Sustainable Private Native Forestry A review of timber production, biodiversity and soil and water indicators, and their applicability to northeast New South Wales RIRDC Publication No. 09/022
Sustainable Private Native Forestry A review of timber production, biodiversity and soil and water indicators, and their applicability to northeast NSW
Alex Jay, David Sharpe, Doland Nichols and Jerry Vanclay Southern Cross University Lismore NSW March 2009
RIRDC Publication No 09/022 RIRDC Project No USC-8A
© 2009 Rural Industries Research and Development Corporation. All rights reserved.
ISBN 1 74151 827 X ISSN 1440-6845 Sustainable Private Native Forestry: A review of timber production, biodiversity and soil and water indicators, and their applicability to northeast NSW Publication No. 09/022 Project No. USC-8A The information contained in this publication is intended for general use to assist public knowledge and discussion and to help improve the development of sustainable regions. You must not rely on any information contained in this publication without taking specialist advice relevant to your particular circumstances. While reasonable care has been taken in preparing this publication to ensure that information is true and correct, the Commonwealth of Australia gives no assurance as to the accuracy of any information in this publication. The Commonwealth of Australia, the Rural Industries Research and Development Corporation (RIRDC), the authors or contributors expressly disclaim, to the maximum extent permitted by law, all responsibility and liability to any person, arising directly or indirectly from any act or omission, or for any consequences of any such act or omission, made in reliance on the contents of this publication, whether or not caused by any negligence on the part of the Commonwealth of Australia, RIRDC, the authors or contributors.. The Commonwealth of Australia does not necessarily endorse the views in this publication. This publication is copyright. Apart from any use as permitted under the Copyright Act 1968, all other rights are reserved. However, wide dissemination is encouraged. Requests and inquiries concerning reproduction and rights should be addressed to the RIRDC Publications Manager on phone 02 6271 4165.
Researcher Contact Details Alex Jay Southern Cross University School of Environmental Science and Management Box 157 Lismore NSW
Dr. Doland Nichols Southern Cross University School of Environmental Science and Management Box 157 Lismore NSW
Phone: Fax: Email:
Phone 02 6620 3492 Fax 02 6620 3492
[email protected]
02 6620 3650 02 6620 3492
[email protected]
In submitting this report, the researcher has agreed to RIRDC publishing this material in its edited form. RIRDC Contact Details Rural Industries Research and Development Corporation Level 2, 15 National Circuit BARTON ACT 2600 PO Box 4776 KINGSTON ACT 2604 Phone: 02 6271 4100 Fax: 02 6271 4199 Email:
[email protected]. Web: http://www.rirdc.gov.au
Printing by Union Offset Printing, Canberra Electronically published by RIRDC in March2009
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Foreword The commercial and environmental values of private native forests have become increasingly important following reductions in log supply available from public forests, and with the realisation that achieving biodiversity conservation goals will require sympathetic management of the landscape matrix outside of the formal reserve system. This study reviews the forms of sustainability indicators such as standards and scoring systems that are relevant to private forests of the northeast NSW region. The research is a precursor to developing practical indicators which will help landholders and policy makers determine whether forestry management is likely to maintain or improve environmental outcomes, this being a key criterion in pending State legislation. However this research is independent of State government processes. This project was funded by the Natural Heritage Trust through the Joint Venture Agroforestry Program (JVAP), which is supported by three R&D Corporations — Rural Industries Research and Development Corporation (RIRDC), Land & Water Australia, and Forest and Wood Products Research and Development Corporation1 (FWPRDC), together with the Murray-Darling Basin Commission (MDBC). The R&D Corporations are funded principally by the Australian Government. State and Australian Governments contribute funds to the MDBC. This report is an addition to RIRDC’s diverse range of over 1800 research publications. It forms part of our Agroforestry and Farm Forestry R&D program, which aims to integrate sustainable and productive agroforestry within Australian farming systems. The JVAP, under this program, is managed by RIRDC.
Most of our publications are available for viewing, downloading or purchasing online through our website: www.rirdc.gov.au.
Peter O’Brien Managing Director Rural Industries Research and Development Corporation
1
Now Forest & Wood Products Australia (FWPA)
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Abbreviations ABARE
Australian Bureau of Agriculture and Resource Economics
AFS
Australian Forestry Standard
CMA
Catchment Management Authority (NSW)
CRA
Comprehensive Regional Assessment (a joint assessment of forest values – environmental, heritage, economic and social – undertaken by the Commonwealth and a State or Territory)
CSIRO
Commonwealth Scientific and Industrial Research Organisation
dEOAM
draft Environmental Outcomes Assessment Methodology, a regulation under NVA
ES(F)M
Ecologically Sustainable (Forest) Management
FSC
Forest Stewardship Council
FWPRDC
Forest and Wood Products Research and Development Corporation
GIS
Geographic Information System
LGA
Local Government Area
LNE
lower northeast region of NSW
MPIG
Montreal Process Implementation Group
MC& I
Montreal Criteria & Indicators
NSW
New South Wales
NVA
the NSW Native Vegetation Act 2003
PNF
private native forests or forestry as the context suggests
s.d.
standard deviation of a sample
SE
standard error of a sample mean
SEQ
southeast Queenland
Qld
Queensland
R&D
Research and Development
RFA
Regional Forest Agreement
RIS
Regulatory Impact Statement
SFM
Sustainable Forest Management
(S)
FNSW Forests New South Wales
UNE
upper northeast region of NSW
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Contents Foreword ...................................................................................................................................iii Abbreviations ............................................................................................................................ iv Contents...................................................................................................................................... v Executive Summary ................................................................................................................. vii Introduction ................................................................................................................................ 1 1. Sustainability definitions........................................................................................................ 1 2. PNF in northeast NSW........................................................................................................... 5 3. The legal and policy context .................................................................................................. 8 4. Certification and standards................................................................................................... 13 5. Biodiversity indicators ......................................................................................................... 16 5.1 What is Biodiversity? ..................................................................................................... 17 5.2 What is Habitat ? ............................................................................................................ 18 5.3 Population Size and Conservation.................................................................................. 19 5.4 Surrogate Species ........................................................................................................... 20 6. Habitat value, site attributes, and spatial and environmental effects ................................... 23 7. Resolving the use of fauna indicators .................................................................................. 27 8. Effects of timber harvesting ................................................................................................. 29 9. Timber production indicators ............................................................................................... 30 9.1 Sustainable silviculture: maintaining an even flow of timber........................................ 30 9.2 Forest condition and removals; regeneration and gap size ............................................ 31 9.3 Economics of stand rehabilitation .................................................................................. 33 10. Soil and hydrological processes ......................................................................................... 38 10.1 The role and function of stream buffers ....................................................................... 38 10.2 Area of stream buffers in UNE NSW PNF .................................................................. 41 10.3 Soil management .......................................................................................................... 42 11. Uncertainty and risk management...................................................................................... 43 12. A comparison of three structural and landscape indices for biodiversity value and sustainability............................................................................................................................. 46 12.1. The Habitat Hectares (HHa) approach ........................................................................ 48 12.2 Biodiversity Benefits Index BBI .................................................................................. 49 12.3 PVP developer and the BioMetric score ...................................................................... 53 13. Adaptive management........................................................................................................ 57 14. Towards an improved index of sustainability .................................................................... 58 14.1 Rationale for, and form of a sustainability index ......................................................... 58 14.2 Integrating time effects in the sustainability index ...................................................... 62 14.3 Conclusion.................................................................................................................... 65 15. References .......................................................................................................................... 66
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List of Figures (note Figures and Tables are numbered according to the sections they appear in the document)
Figure 1 Figure 2 Figure 3 Figure 6.1 Figure 6.2 Figure 9.1 Figure 9.2 Figure 9.3 Figure 14.2.1 Figure 14.2.2 Figure 14.2.3
Components and Process of Sustainable Forest Management. ..................................... 2 Northern Rivers Catchment Management Authority area............................................. 5 Native forest wood supply in NE NSW ........................................................................ 6 Maximum combined spatial and structural heterogeneity in a logged landscape ...... 24 Fauna & Habitat correlation ....................................................................................... 25 A representative stand structure for mixed-age Spotted Gum forest. ......................... 33 Annual growth in value in a simulated stochastic mixed-age Spotted Gum forest stand ............................................................................................ 34 Outcome from EUCAMIX model indicating stand development under three silvicultural regimes. ................................................................................................... 34 Site scoring for BBi over time: ................................................................................... 62 Site scoring for two sites ............................................................................................. 63 Site scoring showing biodiversity credit and debit ..................................................... 64
List of Tables Table 4: Table 9 Table 12.2.1 Table 12.3.1 Table 12.3.2 Table 14.1
excerpts from AFG checklist for compliance with AFS ............................................. 14 Mean NPV outcomes ($/ha) for three silvicultural treatments.................................... 35 Weightings used in BBI vegetation condition score V. .............................................. 51 Vegetation associations. .............................................................................................. 54 The “PVP developer” BioMetric scoring system........................................................ 56 Passport scoring approach for wildlife-BBi ................................................................ 61
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Executive Summary What the report is about Private Native Forests are a dominant part of the landscape in northeast NSW and their future is a matter of great debate. Private Native Forests are an essential component in the supply of building materials to the public, and have historically contributed significantly to regional economic activity. These contributions have been made from the matrix of managed and reserved lands that also provide a complex array of environmental benefits. Sustaining the flow of these benefits is important for landowners, timber and tourism industries, and regional communities in northeast NSW. In recent decades society has expressed concerns about how to integrate forest management techniques for timber production with those that improve the condition of the physical and biological environment. This report reviews our knowledge base of native forest silviculture in this region, including what is known about the current condition of private native forests. Secondly, the report reviews the use of indicators of sustainable maintenance of habitat and discusses their major strengths and weaknesses.
Who is the report targeted at? The report should be read by those interested in understanding the general nature of private native forests in northeast NSW and in the management regimes that have led to their current state. The report also should be read by those with an interest in developing habitat and landscape indices for planning and valuation purposes, including wildlife researchers, forest managers, and policy makers.
Aims/Objectives The aim of the research is to provide background information that will inform the development of a sustainability index for private native forestry to be used by landowners, stewardship incentive program managers, and standards compliance assessors. We aim to develop a standard of care for native forests that incorporates the knowledge base that has been accumulated in the forest and biological sciences.
Methods used The report describes private native forests in northeast NSW and their legislative context, and reviews the use of standards and scoring methods as sustainability indicators, with a particular focus on the differences among the various indices. The effects of timber harvesting practices on fauna, timber production and soil and water processes are discussed, and an efficiency-based approach for dealing with the uncertainties prevalent in long-term resource management is described.
Results/Key findings Sustainability is a dynamic process and cannot be measured by a snapshot view. Within-forest variation across time and spatial scales is desirable to maintain a diversity of habitats, but this leads to problems in reliably detecting long-term trends. Ongoing monitoring is expensive and should be targeted to areas of key concern. Standards are most useful as strategic planning and basic operational “harm-prevention” tools, but do not encourage outcomes above a lowest common denominator. Scoring methods are more relevant for operational-level assessments and to measure trends over time and if appropriately linked to stewardship rewards, can encourage general improvement and promote the most efficient outcomes. Although correlation between habitat attributes and fauna presence is of
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low precision (the presence of suitable habitat does not guarantee presence of targeted fauna), an objectively-scored coarse filter approach fits well with precautionary principles and can be used to prioritise action among sites. Current scoring methods are based on before-and-after site conditions, and are not well suited for forestry operations which involve dynamic forest structures and conditions.
Implications for relevant stakeholders Landowners have to make management decisions about a dynamic system (i.e. the forest) in a complex environment of personal, financial, and legal conditions. By adopting the use of sustainability indicators which account for dynamic forest development and point towards broadly desirable outcomes, landowners can reduce some of this complexity and will be better equipped to adopt a planning and adaptive management framework focussed on their objectives, that will also include environmentally sustainable outcomes. The community – through work on specific pieces of forest - will have more visible indications that private native forests are being responsibly and sustainably managed. Policy makers and strategic planners will have a greater resource of information to use, and will be better able to choose and prioritise between alternative actions.
Recommendations The second phase of this research aims field test some different forms of indicators in the widespread, commercially important dry Spotted Gum forest type, and develop a “toolkit” to simplify the measurement and interpretation of the indicators. The outcomes of this exercise will be relevant to landowners and policy makers, who need specific measures they can use to distinguish well-managed from poorly-managed or abandoned forests.
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Introduction The direction of management of the vast private native forestry estate in NSW is an important and contentious issue. The purpose of this review is provide theoretical and practical guidance for assessing the maintenance of biodiversity, timber production and soil and water values in private forests in the northeast region of NSW. The SCU research team has proposed developing and field testing an index of sustainability, based on the information in this review.
1. Sustainability definitions There is currently great discussion of “sustainability” across all realms of society. Concerns fall into the environmental, social and economic spheres and the goal in most consideration of sustainability is to define how to balance these three elements in a given system. Sustainable forestry is presently defined by use of criteria and indicators. “The criteria are general principles that express commonly agreed upon objectives…., while the indicators are designed to assess whether these objectives are being met” (Brand 1997, cited by Di Stefano 2001). A well-known and widely-adopted example is the Montreal Criteria and Indicators (MC&I). MC&I in turn provide the basis for the Australian Forestry Standard (AFS) which is a quality assurance scheme to certify that participants are following particular processes in forest management. Under the Montreal Process sustainable forestry is achieved when these goals are met: • • • • • •
Maintenance of productive capacity of forest ecosystems. Maintenance of forest ecosystem health and vitality. Conservation and maintenance of soil and water resources. Maintenance of forest contribution to global carbon cycles. Maintenance and enhancement of long-term multiple socio-economic benefits to meet the needs of societies. There is a legal, institutional and economic framework for forest conservation and sustainable management.
One of the most common concepts of sustainability is that of a steady “flow” of services or materials derived from “stocks” of natural resources. The idea of outputs in perpetuity is intuitively reasonable, but needs to be qualified with the condition that such outputs do not arise from running down the capital stock, eg harvesting faster than growth rate. Sustainability is therefore by definition dynamic, and cannot be measured by snapshot views of the resource or system being considered.
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The process of assessing sustainability is a cycle and suitable indicators are context-dependent (Vanclay 1995), as illustrated in Figure 1 based on Di Stefano (2001) and Chesson (2002)
Subdivide the goals until measurable operational criteria are possible Aggregate lower level indicators to form a core set for assessment and reporting without destroying information content Establish baseline levels and critical change levels to trigger action
Define sustainable forestry objectives and goals
Social values Ecological values Economic values
Select indicators that measure status of criteria & goals
Forest management practices
Change Implement monitoring program
Test for change in indicators
Don’t change
Management Decision
Figure 1 Components and Process of Sustainable Forest Management.
Identifying the core objectives is important at the outset so that the indicators don’t become a defacto goal in themselves. Furthermore, indicator measures must be practical to collect and monitor and have meaning and benefit for the land managers who will ultimately be using them. Achieving a balance between simplicity and accuracy is an ongoing challenge. The critical level of change that triggers management changes, and the probability and cost of correctly detecting it, are issues that need wider recognition (Di Stefano, 2001). Long a focus of forest management, as opposed to forest exploitation, has been the concept of “sustained yield”, meaning that the forests of a region or country should not be harvested at a rate greater than their growth. The idea of outputs in perpetuity is embedded in the phrases “sustainable development” and “ecologically sustainable forest management” (ESFM) and while various definitions of these focus on either end-points or on processes, most incorporate the “triple bottom line” of environment, economy and social conditions. “Sustainable development” embodies the broader idea of tradeable (fungible) natural, social and economic capital (Pearce & Turner 1990) whereas ESFM would initially seem to be more focussed on flows and stocks within the boundaries of a geographically defined biological system. However this seeming distinction between ESFM and SD may be misleading. In Australia, ESFM definitions start from the 1995 National Forest Policy Statement (Anon 1995) where the broad principles of ESFM have been summarised as [ RFA (2000 ) ; Attachment 14 ]: •
Maintain or increase the full suite of forest values for present and future generations across the NSW native forest estate. Aims for values include biodiversity; the productive capacity and sustainability of forest ecosystems; forest ecosystem health and vitality; soil and water; positive contribution of forests to global geochemical cycles; long term social and economic benefits; natural and cultural heritage values.
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• • • •
Ensure public participation, access to information, accountability and transparency in the delivery of ESFM. Ensure that legislation, policies, institutional framework, codes, standards and practices related to forest management require and provide incentives for ecologically sustainable management of the native forest estate. Apply precautionary principles for prevention of environmental degradation. Apply best available knowledge and adaptive management processes.
Indicators are indirect or proxy measures for assessing whether goals are being attained. Indicators of sustainability have been used at a range of scales from the broad national level (Yale Univ CELP, 2005) to specific resource elements in a particular context, for example plantation soil management (Carlyle et al 2003). Since it is not possible to monitor or measure everything, or even measure some items directly (e.g. “conservation of biodiversity”), ESFM can only be implemented by having measurable, scientifically valid indicators of progress or outcomes. However given the broad objectives, such indicators are, not surprisingly, difficult to formulate. In this review we have adopted the position that assessing sustainability is best done as a scientific, positive, objective process, while moral philosophy or normative value judgements create the social context from which management goals are derived. The Australian State and Federal parliament’s views of the essential aspects of ecologically sustainable development might perhaps best be gauged from statutory definitions of this term. These are to be found in (i) Sect 6(2) of NSW Protection Of The Environment Administration Act 1991 (POEAA) from whence the definition is carried across into other Acts including the Native Vegetation Act (NVA) 2003, and (ii) Sec 3A of the Commonwealth Environmental Protection and Biodiversity Conservation Act 1999 (EPBCA). In summary the definitions encompass (a) the precautionary principle - notwithstanding scientific uncertainty, avoid irreversible damage by considering risk-weighted consequences (b) inter-generational equity - ensure a full range of options is available to future generations (c) conservation of biological diversity and ecological integrity- a fundamental consideration (d) improved valuation, pricing and incentive mechanisms- environmental factors should be transparently valued in pricing of assets and services Thus both Commonwealth and State legislation indicate four primary principles of sustainability. The Commonwealth also says “decision-making processes should effectively integrate both long-term and short-term economic, environmental, social and equitable considerations” ( EPBCA 1999 sec 3A), and the clause in the NSW State Act (POEAA 1991) concludes … environmental goals, having been established, should be pursued in the most cost effective way, by establishing incentive structures, including market mechanisms, that enable those best placed to maximise benefits or minimise costs to develop their own solutions and responses to environmental problems. Clearly, parliament has perceived that equity and efficiency are important elements of ecologically sustainable development, and that regulatory mechanisms alone will be ineffective. ESFM is a primary driver of public forest management in the Upper North East (UNE) region of NSW (SF NSW 2004, 2005). The NSW government has also confirmed its commitment to “the achievement of [ESFM]… on Private Land …” (clause 46, RFA 2000). The signed RFA document further noted that arrangements for attaining ESFM on private lands would comprise • a process of encouragement of private landowners (cl. 55), • a Code of Practice for PNF (cl. 57), • voluntary participation by landholders in schemes to achieve conservation objectives (cl. 56),
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and that conservation levels achieved in the Comprehensive, Adequate and Representative (CAR) reserve system on public lands would not be used as a basis for preventing timber harvesting on private lands (cl. 59). Broadly, the assessment of socio-economic sustainability of forest land use decisions include various permutations of Benefit-Cost Analysis taking into account market and non-market values (e.g. Sinden & Worrell 1979). It is not proposed to go into detail on those aspects in this review; Jay (2005a) provides an overview. Some further comment on economic aspects of sustainability is in section 10. (‘Uncertainty and risk management’).
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2. PNF in northeast NSW The discussions in this report are relevant to the area of NSW from about Port Macquarie to the Queensland border, and inland to the New England Highway. This includes the Northern Rivers Catchment Management Authority (CMA) Area (Figure 1), which in turn encompasses the northern third of the Lower North East (LNE) Regional Forest Agreements (RFA) area and all except some western parts of the Upper North East (UNE) NSW.
Approximate division between upper northeast and lower northeast RFA regions
Figure 2
Northern Rivers Catchment Management Authority area
(source http://www.cma.nsw.gov.au/)
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Private Native Forestry (PNF) is a significant economic and land use activity in the region. In 1999 some 40% of the 450,000m3/ annual hardwood log intake of the UNE region’s mills was being sourced from private land. Public forest supply has declined substantially since the early 1990’s and is projected to decline sharply again in about 20 years or less as shown below. High Quality Large (HQL) logs are likely to constitute progressively less of the total volume over time.
Private UNE State Forests HQL HQS
Projected Wood Supply from northeast NSW (UNE + LNE) public forests (SFNSW 2005) 800,000
95
85
20
75
20
65
20
1995
45 55
1990
35
1985
20
1980
25
1975
0 20
year
200,000
15
-
400,000
20
100,000
native 600,000
05
m 300,000 3/ yr 200,000
plantation
20
400,000
20
An n u al Volu m e (m 3 ) for 5 year periods
500,000
20
LQ PNF une+lne
20
Native Forest Hardwood supply ; UNE+LNE (DAFF,
Figure 3 Native forest wood supply in NE NSW (a) actual (b) projected from public forests
Total employment in the hardwood timber industry sector in NE NSW was around 1200 persons excluding private native forest landowners, and the industry contributed some $220M annually to the regional economy in the form of timber, wages, value-adding and other payments (CARE et al 1999). However the private log supply is on a steep downward trend in both UNE and LNE, having halved between 1975 and 2000. Countering this trend are short term spikes in private log supply which have occurred as a response to withdrawals of public forest from the production estate. (DAFF 1999a). The private native forests of the region are comparable in extent to the public forests (State Forest, National Park, Nature Reserves and Crown Land combined); PNF is in fact slightly larger than the public forest area in UNE. About 60% of the combined UNE and LNE land area (9.7M ha) has forest cover (5.6M ha), and about two-thirds of the forest cover on all tenures is potentially productive native eucalypt forest types (3.8M ha). Nearly half of this (1.7M ha) is privately owned, being divided about 0.8/0.9M ha between UNE/LNE respectively (Keenan and Ryan 2005). Dry Spotted Gum (Corymbia maculata, C. variegata and C. henryi) and Dry Blackbutt (Eucalyptus pilularis) broad forest types comprise about a third of the potentially productive private forest, and these two species provided about half of the total (public and private) log volume supplied to mills in the late 1990’s. (DAFF et al 1999). Spotted gum logs are more predominant in the north and blackbutt in the south. In 1998 there were around 145 licensed sawmills in the UNE area. Fifty-five of these receive Crown logs and of those, only 8 receive>10,000m3/yr, and 28 receive< 1000m3/yr (Fortech 1999). The intake of one large company (Boral Ltd) amounts to ~ 60% of the total Crown supply. Most larger sawmills supplement their State Forest allocations with private property resource, whilst a large number of small mills rely totally on private forestry harvests. Nearly three-quarters of the public forest
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hardwood sawlog sales are for floorboards (42%) and house framing (22%) and other dry structural products (11%) (FNSW 2004). A number of studies have considered economic development opportunities, supply scenarios, and the role of PNF in the regional economy. These include CARE et al (1999), Fortech (1998), NNFS (1994, 1999, 2000, 2002), MGP, Powell and James (1995), DSD (NSW Dept State Development) (1989) CARE et al. (1999) has detailed socio-economic and statistical information including regional input/output matrix, employment and value multipliers. Compiling various figures from these reports suggests that around two-thirds of the total potential current private sawlog and roundwood supply is currently being made available to industry by landowners in the UNE region, which translates to an annual average (sawlogs & other roundwood only) yield of 0.8 to 1.0m3/ha/yr from a net production estate (after accounting for intent, accessibility and net harvestable area) of around 150,000 to 180,000 ha in UNE region (Jay 2005 in prep c). Jay (2005a) reports on landowner management intent for the UNE region, and estimates an upper limit of annual harvested area (selection harvest not clearfell) to be at most about 12,400 ha or 1.0% of the gross PNF estate. Data is no longer kept by State Forests of NSW on the annual volume of logs that mills source from private forests. Sustainable future supply is dependent not only on the net available area of the forest but also its silvicultural condition and non-declining biophysical conditions. The PNF estate is in generally poor productive condition, having had a long history of indifferent management and/or high-grading, meaning removal of commercial stock without due attention to silvicultural improvement treatment. Jay (2005c) found that the most common structure in inventoried PNF plots in Spotted Gum and Blackbutt types was one where the predominant biomass (basal area) class was trees 10-25cm diameter, with very few trees in the >70cm DBH classes. However Keenan and Ryan (2004) list 234,000 ha of UNE PNF or some 20% of the total private forest as old-growth (i.e. predominantly mature forest where effects of disturbance are now negligible and regrowth cover is less than 30% of total). They also note that 371,000 ha of old-growth or 57% of the total 655,000 ha area of old-growth on both public and private land, is in formal and informal reserves. Both of these contrasting structures are relevant to future supply, since the poor silvicultural condition of the regrowth dominated stands means they are unlikely to be a source of significant volumes of timber for some time (especially the high quality large logs which are in short supply), and regulatory constraints may prevent harvest in old-growth stands. Private forests in northeast NSW are also important for their conservation, biodiversity, water quantity and quality, landscape aesthetics and other environmental values. However as non-market, nonexcludable products (i.e. goods or services), the continuing supply of these values (products) from private land is dependent on either (i) landowners managing their forests to supply their own demand for the products, (ii) the development of market systems to generate value from the products, or (iii) regulatory systems to coerce, control or command supply of the products. Young et al (1996) have comprehensively discussed voluntary market-based instruments to promote conservation of biodiversity. Markets for ecosystem services are the subject of a scoping study by Binning et al (2002), and are also discussed by ABARE (2001), van Bueren (2001) and The Productivity Commission (2004). Pannell (2004) provides perhaps the most accessible and comprehensive introduction. Figgis (2004) suggests that the role of market incentives is to reward provision of valuable services, not to provide compensation for a hands-off prescription. Gillespie (2000) cites some costs of native vegetation ownership on private land in NSW; direct costs of managing remnant vegetation in the Riverina averaged around $2400 per annum per property, and for 89% of landholders the sum of direct plus opportunity costs of native vegetation retention exceeded agricultural productivity or other directly marketable benefits obtained on site. Pilot incentive-based schemes have been trialled in NSW, but prescriptive regulation appears to be the most likely form of government interventions in PNF in NSW (DIPNR, 2004).
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3. The legal and policy context Private native forest harvesting or other silvicultural action in NSW is regulated primarily under the Native Vegetation Conservation Act 1997 (NVCA). Harvesting on steep land (>180 slope) or other protected land is subject to approval and conditions set by the Department of Natural Resources (DNR, formerly DIPNR). Although the NVCA was repealed by Parliament in December 2003 and replaced by a new Native Vegetation Act (NVA 2003), this is yet to be gazetted so the provisions of the 1997 Act continue. Under the NVCA, where a Regional Vegetation Management Plan is not in force, as is the case for the northeast, some forms of “clearing” continue to be exempt from the NVCA 1997 under transitional provisions in that Act retained from State Environmental Planning Policy SEPP 46 Schedule 3. These exemptions include (i) The clearing of native vegetation in a native forest in the course of its being selectively logged on a sustainable basis or managed for forestry purposes (timber production). There are no statutory definitions of the meaning of “sustainable” in this context, and the interpretation of this provision is subject to guidelines issued by DIPNR. These state, inter alia, Selectively logged on a sustainable basis is taken (as adapted from Smith and van der Lee 1992 [ref unknown]) to be felling and removal of part of a forest for the purpose of selective timber production which, at a minimum, maintains: • habitat value; • an uneven age forest structure; • more than 50% retention of trees greater than 40 cm dbh (diameter at breast height) on a broad area basis in each logging cycle; and • the forest in a state from which it can recover to a similar structure before next logging cycle. ……To be eligible to claim this exemption, therefore, it would be reasonable to expect a private- native forest owner to be able to furnish evidence of the application and accomplishment of these sustainable land practices through some form of forest management plan…… ……This means that there should be clear evidence of the continuous passage or progress through time of a succession of stages of forest management practices……. (http://www.privateforestry.org.au/exempt4.htm ) “Sustainable” practices are thus prescribed by an administrative interpretation rather than by Parliament, with a strong if not mandatory need for documentary support and evidence of intent. As far as is known, has not been tested in the courts. Northern Rivers Private Forestry Development Committee cautiously considers that …….By and large the current exemptions do not cover normal forestry operations such as selective logging… http://www.privateforestry.org.au/private_nat_for_res_ntnsw4.htm This current status of exemption by administrative interpretation was clearly never intended to be a long-term provision. The NVCA intended that Regional Plans would eventually supercede the SEPP 46 provisions, however the draft Plans were highly controversial and the NVCA was repealed prior to their gazettal as a regulation. Only two, Riverina-Highlands and Mid-Lachlan, appear to have become statutory instruments (http://www.austlii.edu.au). Prior to the introduction of the new Act, a working group of appointed members of the public, NGOs and government agencies produced a report recommending the adoption of a Code of Practice for PNF and the form this might take
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Currently forest landholders are encouraged to follow the “Interim Best Operating Standards for Private Forest Harvesting”,(http://www.dipnr.nsw.gov.au/nativeveg/plantations/pnf.shtml 42pp); however this document has no legal force except where it is attached as a condition for harvesting on Protected Land or on a “clearing approval” when landholders make an application under the NVCA 1997 if they are uncertain about or unable to exercise the “sustainable forestry” exemption. The more contentious conditions of the proposed Code include • • • • • •
Requirement to prepare detailed forest management and harvest plans Continued responsibility to survey/manage for Threatened Species Riparian buffer zones from 10 to 40m Retention of minimum basal areas 12-18m2/ha depending on site height Retention of habitat trees and recruits additional to those in buffers or unlogged areas. Associated additional costs of planning, operations, and loss of management control and sovereignty
The NVA 2003 was passed in the same parliamentary session as legislation which created Catchment Management Authorities. CMAs are appointed boards with statutory responsibilities for planning and implementing natural resource policies. A major role of the CMAs will be to approve or modify Property Vegetation Plan (PVP) applications. Submitting PVPs is voluntary, but once approved they become binding on the title for a term of 15 years and may only be varied with the Minister’s consent. PVPs determine vegetation management on the property in that period. It is still unclear whether the NSW government intends that the CMA be a determining authority for PNF proposals within a PVP, or whether this role will be retained by DNR. In the Minister’s second reading of the Act, he said… The Hon. MICHAEL COSTA (Minister for Transport Services, Minister for the Hunter, and Minister Assisting the Minister for Natural Resources (Forests)) I will take this opportunity to explain how the Government intends to deal with the issue of private native forestry. It is intended that a regulation will be made to include a code of practice for private native forestry. If private native forestry operations conform with that regulation, a PVP will be approved. The code of practice will be developed in full consultation with PNF stakeholders including the growers. Conforming operations should be able to be processed quickly. If necessary, interim arrangements can be established through the regulations to continue the current exemption under the Native Vegetation Conservation Act 1997 until the new arrangements are in place. Using this approach, the Government aims to avoid disrupting current operations, particularly those on the North Coast. (NSW LEGISLATIVE COUNCIL Hansard, Page: 5947 Friday 5 December 2003 http://www.parliament.nsw.gov.au/prod/parlment/hansart.nsf/a60a6a8d2db7ace1ca256e6a002 4cf47/de871b888ec6a4ffca256dfd002147a8!OpenDocument ) Following the passing of the NVA 2003, a new group was formed to revisit the formulation of a Code under this new Act,. This group met throughout 2004 without coming to agreement on basic matters, including acceptable numbers of hollow trees and minimum basal areas to be retained. The original group has not been reconvened since October 2004. However according to DNR a draft Code of Practice for PNF is continuing to be developed .(http://www.dipnr.nsw.gov.au/nativeveg/plantations/pnf.shtml – accessed November 3, 2005).
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The overarching principle in NVA 2003 is that any clearing is only to be permitted if it “improves or maintains environmental outcomes” ..“in accordance with the principles of ecologically sustainable development” (NVA 2003 sec 3(b) ). The intention is that landholders who operate in accordance with a PNF Code under the Act will be deemed to be automatically complying with this principle. An assessment of whether other clearing (including forestry operations not in accordance with the PNF Code) meets the “maintain or improve” test is to be a carried out using a defined methodology (draft Environmental Outcomes Assesssment Methodology, henceforth dEOAM). dEOAM will be given statutory authority by reference from the Native Vegetation Regulations (NVR sec 18[2]) which have been made under part 32(b) of the Act (NVR Part 5 secs 18 & 20). The NVA 2003 distinguishes between “regrowth” and “remnant” vegetation, and generally only applies restrictions to clearing of remnant vegetation. In the northeast region, remnant vegetation is defined (sec 9 ) either as that which has regrown since 1990, or since another date specified in a PVP. This differs from the generally understood definition of “regrowth” forest as that which has grown since abandonment of human-cleared areas. However the NVR (sec 9) permits a PVP to vary this date only if there has been two occasions of clearing “pursuant to existing rotational farming practices” since 1950. Sec 9(3)(a) of the Act defines the latter as those “that are reasonable and in accordance with accepted farming practice”. It is unclear whether “rotational farming” includes intermittent sustainable forestry harvest, although clearly PNF has not been specifically or purposefully included. The dEOAM has an extensive list of forest types (“Keith Formations”, Appendix D in dEOAM) grouped by CMA region in which any “broadscale clearing” will be prohibited if less than 30% of the original extent remains. Of the potentially commercial forest types in this category in UNE NSW, most are tableland occurrences (Stringybark, Peppermint, Brown Barrel, Messmate and Manna Gum types); Swamp Mahogany is the only affected coastal type. If the Act and current general draft regulation are gazetted without a PNF Code, it thus appears that PNF will be immediately subject to the same general provisions as all other “broadscale clearing”. As will be noted later , the effect of this would be to make PNF immediately inoperable. The legislative power to make separate specific provision for a PNF Code appears to be possible either (i) under sec 32(b) of NVA whence the present NVR and dEOAM have been derived, but noting that these do not currently exclude PNF, or (ii) declaring PNF to be a conditional “routine agricultural management activity” under Sec 11(2) of the new Act. Various aspects of a prescriptive regulatory Code do not appear to conform with other policy directions taken earlier by the State government. The NSW Cabinet office (1995) states….. The removal of overly prescriptive provisions...is consistent with the government policy for more efficient regulation established by the Regulatory Review Unit of the NSW Cabinet Office. The best practice approach requires that regulatory proposals: • • • • • •
• • •
have clear objectives and focus on fixing identified problems regulate ends not means maximise benefits and minimise costs are integrated with other regulatory systems so that the public is presented with requirements that 'make sense' across government as a whole minimise the number of government agencies involved promote certainty (so that the assessment of applications for approvals, permits, licences, etc is based on clearly stated criteria and the timeframe for the assessment process is indicated publicly) are simple for the users to understand are simple to administer are easy to enforce
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• • • •
have a high voluntary compliance rate are subject to regular review do not restrict competition use commercial incentives rather than command and control rules, for example by: o information provision o encouraging voluntary compliance backed up by a statute only where necessary o attaching monetary value to reduction in environmental harm o tying the long-term commercial interests of natural resource harvesters to their current management of the stock o providing accessible legal remedies so that consumers, rather than government, can act to enforce their rights without prohibitive costs The above is an edited extract from a 1995 NSW Cabinet Office publication: “From Red Tape to Results - Government Regulation: A Guide to Best Practice”, which was the subject of “Memorandum 95-11; Regulatory Reform- Memorandum to all Ministers”, an instruction from the Premier Mr Carr to adopt such criteria in the interests of best practice regulation. These form a suitable set of criteria against which to evaluate a draft PNF Code. Other legislation which has direct impact on management of PNF include the NSW Environmental Planning and Assessment Act 1979 as amended (EPAA), and the NSW Threatened Species Conservation Act 1995 as amended (TSCA). The EPAA defines protocols for assessment of development applications which are referred to in NVA, but otherwise is relevant principally in that it allows continuance of existing lawful use (Sec 107[1]), notwithstanding a change in any environmental planning instrument which may affect the land. However a burden of proof may rest with the landowner who wishes to claim an existing use of intermittent forestry operations, since Sec 107 [3] states that “a use is to be presumed, unless the contrary is established, to be abandoned if it ceases to be actually so used for a continuous period of 12 months.” Whether a forest is “used” for production while growing between cutting cycles has not been tested in the courts. Changes of scale or intensity of use are specifically denied under the existing use provision. The TSCA aims to prevent development activities significantly damaging listed “threatened species [both animal and vegetable], populations and ecological communities” A significant impact triggers a Species Impact Statement (SIS) which will usually explain or propose some mitigating modifications to the proposal or compensatory offset actions. The burden of proof is on the proponent of the activity to demonstrate by means of an eight-part test (sec 94) that there will not be any significant impacts from the proposed activity. Specific activities may also be listed as “key threatening processes”. Forestry per se is not included in this list but certain listed threatening processes are relevant (e.g. clearing of native vegetation, removal of dead wood and dead trees, high fire frequency; Sched 3 TSCA) The Commonwealth Environment Protection and Biodiversity Conservation Act 1999 (EPBCA) relates to biodiversity issues on a national scale, irrespective of land tenure. Developments and/or activities that are likely to have a significant impact on listed species, communities and heritage areas must be referred to the Commonwealth Minister for the Environment for approval. However forestry operations conducted under a Regional Forest Agreement are exempt from EPBCA 1999 (sec 38, with some exceptions not relevant to PNF). Continuation of lawful pre-existing uses is also exempt (sec 43B). An RFA forestry operation is by definition one which occurs in one of the listed Forest Ecosystems in the signed Agreement (RFA 2000) and is permissible under that Agreement. The listed Forest Ecosystems for UNE NSW cover some 2.1M ha, and include all forested private land including that with candidate old-growth forest and rainforest. No forestry
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operations on private land are specifically excluded under the RFA if they are permitted generally by NSW law. It therefore appears that EPBCA has little direct relevance for PNF in NE NSW.
Given this very murky situation, considerable uncertainty surrounds the continued capacity to harvest logs from NSW private native forests, and landowners are, on anecdotal evidence at least, very reluctant to make any silvicultural investment in improving the productive capacity of their forests when future harvests may not be permitted or are highly restricted.
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4. Certification and standards The recent publication Forests for Tomorrow (CSIRO 2005) provides a succinct overview of current status of sustainability in Australian forestry, but mostly in reference to public forests and the RFA process and outcomes. The RFAs, in agreeing to implement ESFM, drew substantially on standards derived from the 1993 Montreal Criteria and Indicators (MC&I) for sustainable forest management. Australia is one of 12 nations which have endorsed the MC&I (MPIG 1998, AFFA 2005). Collectively these countries encompass some 90% of the world’s temperate and boreal forests and account for 45% of world trade in wood and wood products. The MC&I cover broad forest values that society seeks to maintain eg • socio-economic benefits • conservation of soil & water • ecosystem health • forest productivity • conservation of biodiversity Indicators are intended to provide measures of change in the criteria over time. In Australia extensive research has been undertaken to investigate where and how these may be applied and reported at regional levels. Turner et al (2003) reviewed this research and concluded that only a limited number of the total of 67 national-level indicators had regional relevance. Many of the indicators comprise lists or quantities of some description, for example status of threatened species, removal of wood products compared with sustainable volume, employment in the forest sector etc. Others are reported in narrative form, eg capacity of institutions and legal framework. Chikumbo et al (2001) highlighted the distinctions between strategic-level and operational-level assessments and planning for sustainability. Strategic planning is a long-range landscape or regionalscale process that provides a framework for guiding and constraining short-range (i.e. operational) site–level processes. This means that for PNF, strategic planning is primarily the province of policymakers, while operational implementation is in the hands of landowners. The Montreal C& I generally involve strategic goals, and the indicators are processes of planning or monitoring procedures (e.g. populations of threatened species across their ranges of occurrence), or of an auditable sum of individual operations (e.g. area of forest in protected streamside reserves, area of land affected by soil erosion or compaction). Strategic planning involves either or both of “commandand-control” regulation and behavioural incentives, the simplest of which are price-based. Operational planning is necessarily site-specific, and when both sites and owner’s objectives are highly variable, a policy approach which is heavily-reliant on prescription of practices may be an inefficient means (sensu Sinden 1984) of attaining the strategic objectives. Prescriptive approaches are inefficient because many of the real costs are opaque or hidden, and not directly borne by the beneficiaries. This encourages inefficient allocation of resources. The Australian Forestry Standard is a certification or quality assurance (QA) scheme that is derived from MC&I (AFS 2005). A similarly-structured standard is that of the Forest Stewardship Council (FSC), although FSC is more performance-based (Gullison 2003) than the process-based AFS. New Zealand has legislated standards and guidelines based on MC&I, with a hierarchical system of principles (criteria), goals, indicators and benchmarks. Collectively all of these are referred to as standards, but function at different geographic and management scales. The standards focus on private forest, since the bulk of NZ native forest is Maori owned. SFM plans are required for all significant operations; mills cutting indigenous timber must be registered and are subject to restrictions including export controls (NZ MAF 2003).
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Holvoet & Muys (2004) compared 164 Standards designed to improve or implement ESFM. They found a range of differences principally related to (i) whether they were aimed at national or forest management unit level and (ii) whether they were from developed countries (which tended to emphasise ecological aspects derived from research) or developing countries which emphasised social and economic aspects. Australian Forest Growers, the main organisation representing private landholder forestry other than Farmer Associations, engaged URS Forestry to prepare a checklist of compliance with AFS for smallscale private foresters (AFG 2005). AFS and the AFG checklist both certify that a process is being followed but not that measurable stocks or flows are being maintained. While this is useful as for QA purposes, it does not indicate changes in condition over time except to the extent that the QA processes themselves require monitoring and amelioration of negative change. Some examples from the checklist are in Table 4. Table 4: excerpts from AFG checklist for compliance with AFS
all under Criterion 4 “Maintain the productive capacity of forests” - forest types or ecosystems and oldgrowth forest which are under-represented in the regional reserve system? - known or likely occurrence of threatened (vulnerable, rare or endangered) species, community or relevant habitat? - species (flora or fauna) that are rare at the regional level? (i.e.. May be the only known occurrence in the local area) - habitat of migratory species listed under the Commonwealth's Environment Protection and Biodiversity Conservation Act 1999? - internationally important (Ramsar) wetlands?
4.1.3 Operational plans a/ b/
Do you develop written operational plans prior to each forest operation? (i.e.. establishment plan, harvesting plan etc) Do your operational plans include: - objectives and specifications for the proposed activity? - defined roles and responsibilities? - provision for training of staff and contractors where necessary? - communication and documentation procedures? - contingency or emergency plans to manage accidents and emergencies? (i.e.. Personal injuries, oil spills etc)
4.4.2 Planning operations to ensure productive capacity is maintained
4.1.4 Monitoring system a/ b/
Do you have a system for regular monitoring and, if necessary, updating forest management activities? Does this monitoring system include provision for checking whether: - there has been any new or modified legislation or controls? (i.e.. revised Codes of Practice, new or modified legislation) - actual forest operations met the intended objectives and specifications? - there is room for improvement in any forest operation?
a/ b/ c/
d/
4.3.1 Identification of significant biological diversity values a/ b/ c/
Do you know the average growth rate of wood products and average production of non-wood products from your forest? Do you know the productive area of your forest? Do you know the area of forest that cannot be harvested (streamside buffers, steep areas etc)? Is the timing and intensity of regeneration and establishment, silvicultural and harvesting operations carried out so the productive capacity of the forest site is not compromised?
4.4.3 Silvicultural systems (native forest only)
Have you had a flora assessment done of the forest by a recognised professional? Have you had a fauna assessment done of the forest by a recognised professional? Have you conducted flora and fauna surveys to identify: - threatened (vulnerable, rare or endangered) forest types or ecosystems and old-growth forest that are locally depleted?
a/ b/ c/
Will a silvicultural system be implemented that maintains or improves the productive capacity of the forest? Can you support your choice of silvicultural system by consideration of key ecological factors? Have you reviewed the effectiveness and appropriateness of your silvicultural system(s) over time?
What is an auditable standard in this check list framework ? An auditable outcomes-based measure rather than a prescription of process as in the above excerpts is administratively simple, more certain of meeting the ostensible purpose, and of
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being able a priori to pass the “maintain or improve” test. An objective measure of some outcomes is preferred to compliance with (Code) prescriptions and process constraints. Indicators that rely on forest structure (discussed in a later section) are a useful starting set of attributes which can be measured objectively to compare pre-and post- harvest states, and form a basis for auditing, monitoring and prioritising actions. This must considered part of an adaptive management process since the correlation of such indices with outcomes is yet to be broadly empirically demonstrated. In AFS, the focus is on “continuous improvement” and “not compromising” and “embracing” the principles of sustainability rather than certifying its attainment. AFS does not provide indices for measuring “sustainable “ outcomes of or “improvement” in the context of for example biodiversity, wildlife habitats or silvicultural management. It is an awareness tool not a statement of desirable objectives to be achieved. Certification requires documentary evidence of procedures and is likely to be time-consuming, expensive and “character-building” for small-scale growers (Clarke 2005). Clarke (ibid.) reports first-year audit costs of $3850 for 400 ha of PNF in which 7 ha was thinned. Quotes up to $12,000 were received. To pass the audit, inter alia, a 45 page forest management plan was required, including 26 pages of control documents (i.e. proofs of compliance and certifiability. Audit-points are given for having a written policy, plans, monitoring of processes/outcomes, and (bi)annual written reviews. Certification will not make NSW PNF owners exempt from regulatory controls as currently proposed, but may create some marketing benefits in price premiums or access. Gullison (2003) posed the question “does certification conserve biodiversity?” and concluded that while FSC certification generates improvements to management with respect to value for biodiversity, current incentives are not sufficient to cause the majority of producers to seek certification, nor (especially in tropical countries) to prevent conversion of forest to agriculture. He also cautioned that funds spent on establishing certification and subsequent audits and compliance monitoring and reports may be competing with funds available for direct on-ground works. Generally the MC&I and AFS type of standard and reporting has little applicability at patch or stand level. The NZ example is one of the few that appears to be well-integrated across scales. However some standards or process-based indicators may be useful at operational scales for soil and water management, and are discussed later. Indicators for biodiversity sustainability in forest management are more likely to be effective and efficient if they are outcomes-based measures, even if based on surrogates such as vegetation structures.
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5. Biodiversity indicators This section focuses on the biodiversity aspects of sustainable private native forestry, with a brief overview of the major issues affecting population viability. The types of approaches that may be used to monitor biodiversity and animal habitats are then discussed. The conservation of biodiversity and the maintenance of ecosystem services are key and related elements of sustainable forestry, both on public and private lands. Leslie (1986) suggests that such services are indeed the only reason for the State to invest in forest growing. Managed forests, including private forests, will continue to play an important role in biological conservation because of on-going permanent habitat loss (mainly on private lands) for urban development and agriculture (Recher & Lim 1989; Reed & Lunney 1990) and because a system of conservation reserves will not guarantee that there will be no loss of species (Goldingay & Newell 2000; Kallimanis et al. 2005). Moreover, a rapid expansion in the area of conservation reserves without adequate funding and management may lead to the “benign neglect” of biodiversity. This may produce less beneficial and more costly outcomes than the alternative of continued broadscale forest harvesting at an appropriate intensity (e.g. south-east Queensland: McAlpine et al. 2005). Privately-owned land holds a significant portion of the nation’s biodiversity, and is an essential and integral part of the matrix of reserved and managed landscape (Figgis 2004). The conservation of biodiversity (Criterion 1) and the maintenance of forest health and ecosystem services (Criterion 3) are key elements of the MC&I. Indicators for the criterion of conservation of biodiversity include........ 1. extent and reservation of forest types and successional stages 2. number of threatened forest species 3. number of forest species that occupy a small portion of their former range 4. number of forest dependent species 5. fragmentation (of habitats and reserve); assessed by index related to shape, dispersal/connectivity, 6. area:perimeter ratios 7. population levels of representative species from diverse habitats monitored across their range FNSW conducted some 1500-2000 wildlife surveys each year from 2001-2004 in compartments where harvesting was planned, recording an average number of “sightings” (of 41 targeted species of birds, mammals, bats etc) per survey from 1.4 to 2.0, and an average field cost of just $800-$1000 per survey (FNSW 2004). With total harvested native forest area of 45,000 ha in 2004, survey intensity thus averages one per 30 ha harvested. Sighting densities can be construed similarly. Issues of scale are important as to how these MC&I are applied in practice. It is unreasonable to expect that every small patch of forest should be evaluated, or that assessment only be done on national or state basis. Species’ presence is influenced by factors such as the successional stage of the vegetation, variation in food supply and demographic stochasticity, therefore populations wax and wane with time for any given point in space (e.g. Arpat et al. 2004; Sharpe 2004). Hence headcounts (notwithstanding difficulties in obtaining accuracy anyway) , or more strictly speaking inferences made from absence or low headcounts, are of less value than may be supposed unless they are part of an extensive long-term records. A goal for biodiversity conservation in production forest landscapes might be to maintain the presence and broad distribution of species at a landscape level (i.e. 10,00030,000 ha, or a square with 10-18 km on a side). Species with wide range home ranges (e.g. powerful owl) may be difficult to monitor directly. The approach taken is often to monitor the environment instead, for example (micro-) habitat features such hollow branch abundances, or to focus on easy-to-collect invertebrate indicator species (bottom of
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foodchain, recyclers, pollinators) that are found mainly or exclusively in old-growth or naturally disturbed forest. In the latter case questions remain about which are the key indicator species and how they respond to micro-habitat changes as opposed to landscape level changes (see below for further discussion of indicator species).
5.1 What is Biodiversity? Biodiversity can be defined at a number of levels: genetic, population, species and community/ecosystem (Burgman & Lindenmayer 1998; Clark et al. 1991). Genetic diversity is the level at which natural selection operates. It can be defined as the heritable variation that occurs between individuals, populations and species. While genetic diversity is the most fundamental level of diversity and techniques exist to measure it, it is costly to procure the required information. Within a species, populations are more or less isolated aggregates of individuals that have regular genetic exchange, but that have limited or no genetic exchange with other members of the species outside the population. Diversity at this level occurs because of genetic drift and because each population experiences different environmental conditions (local adaptation). Populations are often regarded as the fundamental unit of conservation as genes cannot exist independently of populations, which are the smallest definable demographic unit (Burgman & Lindenmayer 1998). Biodiversity is used most commonly to refer to the number of species in an area (species richness) and possibly also their abundance (Burgman & Lindenmayer 1998; Clark et al. 1991). The number of species can vary widely in different regions and in different habitat types. Measures of species richness are also scale-dependent and may include introduced species if simple counts are used. Social and political factors often result in a legal mandate that focuses conservation at the species level (e.g. the NSW Threatened Species Conservation Act 1995 (TSC Act)). However, a pitfall of this approach is that variation below the species level may be ignored, for example it has been argued that taxonomically distinct species (e.g. the swamp wallaby Wallabia bicolor is not a threatened species, but its conservation priority is high because it is the only member of its genus) and locally endemic species should be given a higher weighting due to their uniqueness (Burgman & Lindenmayer 1998). A community is an assemblage of populations of different species occurring within a defined area. Communities are therefore derived from the species that comprise them. The community concept is most frequently applied to assemblages of plants; there may be variation in the physical structure of the vegetation both within and between communities. For example, different forest communities may differ in the degree of canopy closure, which may reflect site conditions such as productivity . There may also be variation within a community due to disturbance (i.e. successional stage) (Burgman and Lindenmayer 1998). Such differences may influence the presence of species that are not used to define the community (e.g. fauna, herbs). There is also often a social mandate to protect communities (e.g. rainforest, old growth forest), which is currently being extended to a legal mandate. For example, the TSC Act recognises Endangered Ecological Communities. These communities are based on the occurrence of certain plant species, while recognising that relatively predictable fauna species may occur within them. From the preceding it is clear that the conservation of biodiversity is necessary to maintain evolutionary potential as it provides a buffer against environmental change. In turn, biodiversity is essential to the maintenance of ecosystem services, such as nutrient cycling, pollination and seed transport. Moreover, it can be argued that species have an inherent right to exist and that there is value in simply knowing that this is occurring (e.g. Armstrong et al 2004 cite some examples). Thus, there are ethical, social, political and legal reasons to protect biodiversity. This can be best achieved via the conservation of populations in situ and by conserving plant communities, which provide habitat. Armstrong et al. (2004) describe three forms of biodiversity α, β, γ, being local (patch) level species richness and diversity as measured respectively by (a) indices such as Shannon-Wiener heterogeneity
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(entropy), (b) the difference between various patches (community diversity), and (c) the combined or landscape level total diversity across all patches. The northeast NSW region being examined in the present study has high community diversity (Specht & Specht 1999) and high species diversity (e.g. Calaby 1966), which is a function of its location within the Macleay/Macpherson overlap zone (an area of overlap between tropical and temperate species, in addition to species endemic to the subtropics) (Milledge 1991). The subtropical climate suggests that populations of a species in this area will have genetic and behavioural adaptations different to the same species in different climatic zones. The region has also retained a relatively high degree of natural vegetation, which can support large populations of many species. These populations are likely have retained a high degree of their heritable (genetic) variation. Thus, the claim of high biodiversity in north-east NSW appears to be justified on all levels that are used to define biodiversity (Brown et al 2000).
5.2 What is Habitat ? Species are not randomly distributed throughout the landscape. Rather, their distributions are linked to particular places and features of the environment that favour survival and successful reproduction (Bolen & Robinson 2003; Burgman & Lindenmayer 1998). A species’ habitat is an area occupied (or potentially occupied) permanently or temporarily that contains essential resources or necessary conditions, such as temperature, moisture, food, shelter and cover. Habitat, therefore, refers to the specific areas suitable for a species’ existence. Areas of potential habitat can be largely defined by climate and by the floristic and structural characteristics of the vegetation. It is also important to understand the value of a particular habitat. For example, in some cases habitats may be broadly classified by quality as population sources or sinks. The birth rate exceeds the death rate in source habitats, whereas the reverse is true of sink habitats (e.g. McCoy et al. 1999). Thus, persistence in sink habitats depends upon dispersal from source areas. While it is tempting to focus on source habitats only, research has shown that sink habitats are also important to population stability and persistence (Foppen et al. 2000). Moreover, a species’ can sometimes exist at higher densities in sink habitats due to its social dynamics. Such as situation may arise where socially dominant individuals force subordinate animals into sink habitats. Thus, the source habitat may have a low density of high quality individuals, while the sink habitat may have a high density of subordinate animals. Not all studies that have examined this issue have found support for source-sink dynamics (e.g. Johnson et al. 2005), but this may be partly related the search behaviour (directed or random) of dispersing individuals (Armsworth & Roughgarden 2005) and/or temporal variation between habitats and the associated populations (Tattersall et al. 2004). Considering factors such as source/sink dynamics, demographic stochasticity and fluctuating population size, it becomes evident why models relating habitat quality to population size do not work particularly well (e.g. Pearce & Ferrier 2001). However presence/absence correlations with some structural habitat attributes have been detected for some species (e.g. Lindenmayer et al. 1995; Pausas et al. 1995). Correlations may be low because of chance population fluctuations, or because correlation with static variables may not be adequately discerning important features, for example, when there have been temporal discontinuities in the supply of essential habitat features (Rolstad et al. 2002). Moreover, animal survival may be dependent on a complex range of attributes that are seasonally important, for example, winter flowering species and squirrel gliders. (Sharpe 2004). However, these relationship may not always be understood. The concept of habitat can be further reduced to the niche concept. A niche is a species role within a community (or habitat). The preceding definition refers to a species’ fundamental niche; a species’ realised niche is the region of habitat space occupied in the face of competition, predation, etc. For example, within a forested habitat there will be animals that live on the ground and those that live in trees, those that feed on leaves and those that feed on nectar. Thus, many species may use a given habitat, but the area is likely to be used in different ways by each of the resident species (Krebs 1985). Indeed, the Principle of Competitive Exclusion suggests that different species cannot have complete
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niche overlap. More complex habitats tend to have a greater variety of niches available, which promotes greater species richness. Thus, habitat complexity promotes biodiversity (alpha [within patch] and beta [between patches]).
5.3 Population Size and Conservation Species extinction is essentially a population-level phenomenon. Simply, a species becomes extinct when all of its populations have disappeared. The loss of populations typically occurs when they have become much reduced in size for some reason (e.g. habitat loss) and become increasingly vulnerable to stochastic processes (e.g. demographic variability, catastrophes, disease) (Clark et al. 1991). However, stochastic modelling has shown that smaller connected populations are also likely to survive seasonal crash events, especially if the broader habitat attributes are favourable (Fahrig 2001) and the source of variation is not correlated between patches (see Kallimanis et al. 2005). Provided individuals remain in nearby habitat, the recolonisation of vacant patches may occur by dispersal. Unfortunately, knowledge of source areas is limited and they may vary over time due to successional process and recurrent disturbance. In the context of PNF, it is important to remember that critical source areas for the recolonisation of temporarily vacant habitat following population declines may be larger than single stands. The conservation of biodiversity essentially requires that a sufficiently large number of connected populations and fit individuals of a species are maintained to enable it to persist and to maintain adaptive potential (Reed 2005). Such considerations are based on the effective size of a population, rather than its census size (the number of individuals known to be in a population). The effective size of a population (Ne ) is a measure of the rate that genetic diversity is eroded by genetic drift. It is measured as a proportion of the total (i.e. census) population (N), so the ratio Ne/ N defines an effective population (Kalinowski & Waples 2002; Vucetich et al. 1997). Effective population size can be influenced by a number of factors, such as the breeding system of a species (Nunney & Elam 1994). For example, Ne will be higher in a monogamous species compared to one that is strongly polygynous. Temporal fluctuations in population size will also influence the effective size of a population due to a “bottleneck” effect; species with low fecundity and/or survival will require longer periods to recover from population lows. Therefore, the degree of environmental variation and the frequency of disturbance will be important determinants of effective population size (Kallimanis et al. 2005). The effective size of a population becomes reduced as its amplitude of fluctuation increases (Kalinowski & Waples 2002; Vucetich et al. 1997). Thus, extinction risk is also related to population fluctuations (Vucetich et al. 2000). The question of minimum viable population sizes has been the focus of much research (Thompson 1991). A popular “rule of thumb” was that the minium number of breeding individuals ranges from 50 to 500, depending on time-scale used to define “viable”. The 50/500 rule derives from a presumed short-term effective population size (Ne) of 50 to prevent an unacceptable rate of inbreeding, and a long-term Ne of 500 to maintain overall genetic variability. (Thompson 1991 cites Franklin 1980 and Soule 1980 as the sources for these numbers) However, “the 50-500 rule has a chequered history and is not universally accepted even for terrestrial organisms” (Simberloff 1988), so there is no clear generally applicable threshold beyond which a species can be considered viable. In some cases it may be as low as 20, for example the largest known purebred herd of Banteng cattle is a feral population of around 5000 in Arnhem Land NT which originated from a few cattle abandoned after failed European settlement in 1849. (ABC 2005). Furthermore, low remnant population numbers and possible genetic non-viability has not deterred efforts to conserve animals such as the northen Spotted Tail Quoll, which is known from only 3 noninterbreeding locations in far north Queensland, estimated to have populations ranging from 20 to 280 individuals. (Burnett and Marsh 2004). Data to define Ne/N is rarely available , but may be
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determined from either genetic or demographic methods (Nunney & Elam 1994). Thresholds of nonviability may be more definable, but are a stochastic and, therefore, an impractical target. Nonviability may depend on the demographic structure of the population at the time which coincides with an exogenous crash event (e.g. failure of seasonal food supplies). Thus, population viability must be considered on a case-specific basis. However, two important general points can be made. :•
Large populations are more viable than small ones (Wilcox & Murphy 1985). While this may be obscured in interspecific or inter-population comparisons due to differences in fecundity, survival and dispersal (Fahrig 2001, Tyre et al 2001), the effective size of a population becomes reduced as its amplitude of fluctuation increases (Kalinowski & Waples 2002; Vucetich et al. 1997).
•
Patch size, patch quality (population) and connectivity (meta-population) are important because they will affect size of population, breeding success rates, gene flows, and recolonisation after crash events.
Population modelling may also assist the assessment of population viability. Population Viability Analysis (PVA) is a method of estimating the minimum viable population size, giving a defined probability of persistence over a given period of time. (Thompson 1991). A PVA is undertaken by computer simulation modelling, provided parameters such as mean and variance of age and sexspecific mortality and fecundity rates, age structure, sex ratios, dispersal, and the relationship of these to density, are known or reasonably able to be estimated. Although estimating variances is a particular problem due to the number of samples required and data is often lacking for even well-studied species, it is possible to address this problem by exploring ranges of parameter values and thereby estimating critical values. (Thompson 1991, Goldingay and Sharpe 2004). As an example relevant to this region, Lunney et al (2002) used PVA to model dynamics in an isolated but otherwise healthy northeast NSW koala population. They found an unexpectedly high probability of extinction in the absence of external recruitment. Such extinction events are stochastically driven and management to retain habitat structural features in isolated patches may have little effect at very low population sizes. It is important to note that sources of unpredictability in real populations includes both demographic and environmental stochasticity (May, 1973). Thus, while PVA is a valuable exploratory tool for comparing different management options, the estimates of absolute extinction risk should be viewed cautiously due to the uncertainty associated with model inputs (Brook et al. 2002; McCarthy et al. 2001).
5.4 Surrogate Species Given the large number of species that may be present in an area, and their often competing requirements, there have been proposals to focus on a subset of species, both for management and for monitoring. This would obviously require careful selection of the target species (Carignan & Villard 2002). Several such approaches to simplify biological considerations have been proposed. These can be broadly called surrogate species approaches and include the use of “indicator”, “umbrella”, “keystone”, “flagship” or “focal” species. Like any form of indicator, they are used to provide an efficient means of assessing the target of interest (e.g. biodiversity, effects of disturbance) when it is too costly or time consuming to measure it directly. Unfortunately, the various terms used to describe surrogate species in the literature are used interchangeably, making consistent definition difficult (Caro & O'Doherty 1999). However, some clarification is offered below. The indicator species concept is perhaps the most generic of the surrogate approaches and it can be argued that the other forms really fall within its scope (Carignan & Villard 2002; Lindenmayer et al. 2000). When used more particularly, however, an indicator species is one whose presence is supposed to infer the presence of a broader range of species. They have been used to infer species richness and to estimate the population trends of other biota, such as prey species (e.g. Caro & O'Doherty 1999;
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MacNally & Fleishman 2002, 2004). In turn, the inferred species richness may be used to assist in the identification of areas suitable for conservation reserves, where the aim is to maximise species richness (Tognelli 2005). Indicator species have also been used to identify intact (i.e. long undisturbed) forested areas by focusing on dispersal-limited species (Rolstad et al. 2002), however, this approach may also fall under focal species (see below). Thus, indicator species are used to identify areas of the landscape of particular interest (Caro & O'Doherty 1999). An umbrella species is really a special case of the indicator species approach. Umbrella species are generally regarded to be those with large spatial requirements. The requirements of species with smaller spatial needs are assumed to be encompassed by ensuring the existence of a viable population of the umbrella species. Top-end predators and other large mammals are typically used as umbrella species because they have large spatial requirements. Thus, umbrella species are typically used to identify the size and types of habitats that require protection, rather than being specifically concerned with location (Caro & O'Doherty 1999). Keystone species are those species whose ecological role is important to the maintenance of ecosystem processes (e.g. nutrient cycling, seed dispersal). Accordingly, their loss would compromise ecological functioning. The use of keystone species supposes that we understand ecological function and the role of particular species in those processes. However, our understanding of these issues is far from complete. Moreover, most ecological systems have redundant species, making the detection of ecological changes following the loss of species elusive (Burgman & Lindenmayer 1998). Flagship species are charismatic species used to garner public support for conservation. Thus, flagship species are selected based on appeal (e.g. Koala), size or degree of endangerment (Caro & O'Doherty 1999). Thus, there may be no necessary underlying ecological basis for the selection of flagship species. They may, however, be effective in generating broad public support for conservation, which would be of indirect conservation value. The focal species approach relates surrogate species specifically to threatening processes and other disturbances (Lambeck 1997). Under this approach, a focal species is assigned to each threatening process. The species selected for each case is supposed to be the one most sensitive to that threat. As the remaining species are less sensitive to that threat, their continued presence is inferred by the persistence of the focal species (Lambeck 1997, 2002). The similarities of these approaches is that they all are based upon the selection of a species, or a small group of species, that act as a surrogate for a much broader group of species or, indeed, biodiversity in general. The surrogate species approaches assume that species’ distributions are nested so that predictable assemblages can be identified. This does not appear to be true, particularly at larger spatial scales (Fleishman et al. 2002; Storch & Bissonette 2002). Moreover, it is assumed that species responses to threatening process and disturbances will be relatively predictable, particularly if the species are related or belong to the same functional guild. However, there is no reason to assume that this is true. The principle of competitive exclusion suggests that the concurrence of a large number of species is only possible due to niche partitioning (i.e. each species does something at least a little different from all others, enabling coexistence) (Krebs 1985). Therefore, there is no a priori reason to expect that indicator species should work particularly well at capturing broader ecological information. While such surrogate species approaches appear to have merit and to have met with occasional success (MacNally & Fleishman 2002, 2004; Tognelli 2005), the major critique of them revolves around the lack of a clear link between the management action and the biota, or the indicator and that which it is meant to indicate (Rolstad et al. 2002). Moreover, because each species responds to environmental variation in different ways, responses to disturbance are species-specific due to differences in life
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history (e.g. birth rates, survivorship, dispersal ability). Such factors limit the utility of surrogate species approaches. Thus, most studies have found that such approaches do not work well in practice (Fleishman et al. 2001; Pearce & Venier 2005; Sætersdal et al. 2005), which may be at least partly due to scale-dependent differences in species perceptions of habitat and fragmentation (Storch & Bissonette 2002), the analytical methods used to assess their utility (Mouillot et al. 2002) and statistical power(e.g. Newmark & Senzota 2003).
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6. Habitat value, site attributes, and spatial and environmental effects An alternative or complementary approach to the use of surrogate species is to use habitat-based indices. This makes intuitive sense, as the management of fauna is, in many respects, the management of habitat, particularly in areas subject to human use and disturbance. Habitat-based approaches can be implemented at different spatial scales. Stand-level indices would include resources such as coarse woody debris, hollow-bearing trees, nectar sources, etc. (e.g. Eyre & Smith 1997). Landscape level factors would include the number of patches within a certain radius, the amount of cover within the landscape, the distance between patches, etc. (Turner 2003). Both spatial scales are important to biodiversity conservation and are considered in more detail later. An advantage of these approaches is that they do not require a detailed understanding of habitat requirements for all species, but rely on the maintenance of more general naturalness (hemeroby) and ecological principles such as those espoused by Lindenmayer & Franklin (2002). The latter are discussed in more detail in section 12. At the broadest scale, potential habitat and conservation priorities may be estimated by environmental domains, which are combinations of physical and climatic factors such as slope, aspect, soil type, temperature and rainfall (e.g. Pressey et al 1996). These domains define the broad limits to a species distribution between and within regions. At smaller spatial scales, landscape and stand-level factors become important. One rationale for measures of structural and spatial complexity as surrogates for biodiversity provided by Lindenmayer et al (2000) is that, although studies to more rigorously or empirically establish the effects of logging are needed, forests will meanwhile continue to be logged to satisfy the social demand for timber. Therefore some form of interim indicator is required. They suggest that stand structural complexity (floristic, ground cover, and tree size class diversity), connectivity between forest patches and heterogeneity of disturbance events over a range of spatial and temporal scales are the most useful attributes for such an interim indicator. With regard to landscape heterogeneity, Hunter (1990 p.91) suggests that a log-log straight line relationship between size of logged forest area and number of such patches will maximise spatial heterogeneity and structural diversity and thus provide opportunities for a wide range of habitats. To this might be added the extra dimension of time (Figure 6.1). Note that number of cut areas x size of each cut given in Fig. 6.1 is constant , so each cut size/opening and structural class occupies the same area of the total landscape.
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N cuts
Time Size of each cut area
Figure 6.1 Maximum combined spatial and structural heterogeneity in a logged landscape (after Hunter 1990)
Limitations of spatial indices include different species responses to fragmentation, lack of clear impact thresholds (Lindenmayer et al 2005), and difficulty in differentiating between fragmentation and diminished area effects per se (Cooper and Walters 2002, Fahrig 2003). For many species, (excepting dispersal-limited species), the proportion of critical habitat in the landscape is more important in maintaining populations than its degree of non-consolidation (Turner et al 2003). McAlpine & Eyre (2000) tested a range of landscape metrics to evaluate MC&I (1.1e) ‘fragmentation of forest types in dry eucalypt forests of subtropical Queensland. Using target species of gliders (4) and diurnal birds (6) as well as measures of total bird diversity and nectar-feeding bird diversity, they found that stand structural and compositional attributes were more influential than landscape metrics with scales of influence at stand (2 ha) and various landscape (78-1250 ha) extents. However even the most influential site variables had only weakly predictive ability for counts of most species (R2 ~0.100.17), notwithstanding that the probability of some effect existing was significant (e.g. p
