The effects of climatic factors on radial growth of ...

Beskydy, 2010, 3 (1): …–… © Mendelova univerzita v Brně ISSN: 1803-2451

The effects of climatic factors on radial growth of Norway spruce Picea abies in the Silesian Beskids P. Čermák1), M. Rybníček 2), T. Žid1), T. Kolář2), H. Bočková2), E. Přemyslovská2) 1) doc. Ing. Petr Čermák Ph.D., Ing. Tomáš Žid, Department of Forest Protection and Game Management, Faculty of Forestry and Wood Technology, Mendel University in Brno, Zemědělská 3, 613 00 Brno, Czech Republic, e-mail: [email protected] 2) Ing. Michal Rybníček, Ph.D., Ing. Tomáš Kolář, Helena Bočková, Ing. Eva Přemyslovská, Ph.D., Department of Wood Science, Faculty of Forestry and Wood Technology, Mendel University in Brno, Zemědělská 3, 613 00 Brno, Czech Republic, e-mail: [email protected]

Abstract: Čermák, P., Rybníček, M., Žid, T., Kolář, T., Bočková, H., Přemyslovská, E. 2010: The effects of climatic factors on radial growth of Norway spruce Picea abies in the Silesian Beskids. – Beskydy 3 (1): …–… Monitoring of Picea abies according to a standard tree-ring and correlation analysis was carried out on 9 plots in three forest districts of Jablunkov Forest Administration (Nýdek, Písek, Horní Lomná) in the course of 2008. At each of the plots, 30 samples were always taken by means of a Pressler increment borer. Based on the regional standard annual-ring chronology particularly the increase is evident of radial increments in the second half of the 1990’s, which was interrupted in 2000. A two-year period with increased radial increments followed, which was interrupted again in 2003 and then in 2006. The diameter increment significantly correlates with precipitation in September of the previous year (Nýdek, Písek, the group of all three districts) and precipitation in June of the current year (Nýdek, Písek, the group). The growth of spruce also significantly correlates with temperatures in October of the previous year (Písek, Horní Lomná), in March of the current year (Nýdek, Písek, Horní Lomná, the group) and in April of the current year (Horní Lomná). The negative statistically significant correlation of the increment was found for temperatures in September of the previous year (Písek). Further, negative pointer years were identified. On the basis of results obtained it is possible to conclude that climatic factors of last circa 20 years markedly affected the vitality of stands. In the 1990’s, their effects can be particularly evaluated as predisposition. However, dry and warm weather in 2003 can be considered to be an initiation stressor showing a substantial or even key role in the present health condition of stands. Keywords: Silesian Beskids, Picea abies, tree-ring analysis, temperature, precipitation

Introduction

decline where synergetic effects of the larger spectrum of factors can be expected it is suitable to monitor, except the actual response of a tree (defoliation etc.), its general vitality. Vitality is understood as an ability to survive the effect of stress (Larcher 2001), i.e. as capacity to live, grow and develop or to assimilate carbon, to resist the stress, to adapt to changing environmental conditions and to reproduce.

At monitoring the decline or dying of trees, it is mostly rather complicated to determine the response of trees to stressors. Monitoring the manifestations of decline is usually relatively short-term starting aer the first more marked symptoms. Thus, it can provide rather a picture on the mortality or initiation factors than on predisposition factors. To interpret non-specific 1

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P. Čermák, M. Rybníček, T. Žid, T. Kolář, H. Bočková, E. Přemyslovská

Radial growth is a suitable indicator of the tree vitality for longer time periods. In a number of cases (e.g. extreme summer drought), growth responds immediately whereas, for example, defoliation or other visible responses are evident aer a certain delay. Factors of the environment affecting physiological and growth processes of trees are permanently stored in the structure of created biomass. In principle, trees monitor environment conditions through the structure of their annual rings (Fritts 1976). In other words, intensity of these factors reflects in the radial growth of trees. Thanks to the tree ring analysis it is possible to obtain back information for long periods and to use it in connection with particular stressors. At the evaluation and interpretation of data it is necessary to take into account evident growth fluctuations in both directions. Low growth will indicate (with high probability) reduced vitality while extremely high growth can (under certain conditions) subsequently induce decreased vitality. The Silesian Beskids, particularly LS Jablunkov (Forest Administration Jablunkov) were affected by the progressive impairment of the health condition of Norway spruce stands. Aer primary symptoms of yellowing, the extensive part of stands dies back, namely individual trees as well as their groups. Stands of all age categories are affected. Present surveys conclude that the present health condition of spruce results from the complex of causes (climate, the stock and availability of nutrients, Armillaria sp. and other fungal pathogens, bark beetles etc.), which differ in the weight attributed to particular factors. Generally, according to Manion (1981), the dying has parameters of the forest decline (decline disease) or complex disease. It is probable that, climatic factors play an important role in the complex of causes. The aim of the paper is to use standard dendrochronological methods and the analysis of climatic data and to identify the response of radial growth to the course of meteorological elements and subsequently to evaluate the importance (the rate of effects) of climatic factors for the vitality of stands. Material and methods Monitoring was carried out on nine plots in three districts of LS Jablunkov during June– August 2008. The first three plots were selected in the heavily damaged district Nýdek, other four plots were selected in the Písek district and last two plots in the Horní Lomná district. All plots occurred in the 5th forest vegetation zone (alti-

tude 601–794 m), predominantly at mesotrophic sites, see Tab. 1. In the course of vegetation season 2008 was realized habitual tree diagnostics according to Cudlín et al. (2001). The plots had similar defoliation. The average defoliation was 34%, the minimum defoliation was 28% (Písek 3), maximum defoliation was 37% (Nýdek 3). In the most of trees, the yellowing was not presented or was to 5% of a crown. Sampling and processing the samples were carried out according to a standard dendrochronological method (Cook, Kairiukstis 1990). At each of the plots, 30 samples were always taken for dendrochronological analyses (in total 270 samples). Samples were taken by means of a Pressler increment borer. Increment cores were carried out at a height of 1.3 m above the ground. The samples were taken along the contour line so that increment is not influenced by the presence of compression wood. Only one sample was taken from each of the trees. Measurements and sating the samples were carried out using the PAST 32 program. Annual increments were measured accurate to 0.01 mm. Particular annual ring series were exported from the PAST 32 program to the ARSTAN program (Grissino–Mayer et al. 1992) where their detrendation was carried out and autocorrelation was removed. Detrendation is removing a trend in a tree-ring whatever the origin of this trend (effects of tree age, etc.). The removal of the age trend was carried out using a two-step detrending method (Holmes et al., 1986). First, a negative exponential function or a linear regression curve, which best express the change of the growth trend with age, were used (Fritts et al., 1969). Other potentially non-climatically conditioned fluctuations of values of thickness increments, brought about by e.g. competition or forester’s interference, were balanced using the cubic spline function (Cook, Peters, 1981). The chosen length of the spline function was 67% of the detrended tree-ring curve length (Cook, Kairiukstis, 1990). On the basis of detrended annual rings, index residual annual ring chronology was created in the ARSTAN program. To model a diameter increment depending on climatic characteristics the DendroClim soware was used (Biondi, Waikul 2004). The climatic time series of average monthly temperatures and precipitation was built from Jablunkov meteorological Czech Hydrometeorological Institute station data (N 49°35´38,04; E 18°44´39,12). The series covers the period from 1961 to 2007.

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The effects of climatic factors on radial growth of Norway spruce Picea abies in the Silesian Beskids

Tab. 1: Characteristics of monitored plots GPS

Age of stand

Edaphic category (Plíva 1971)

Nýdek 1

N 49°40.879 E 18°46.984

78

mesotrophica

778

NW 280°

20°

Nýdek 2

N 49°40.177 E 18°47.036

83

lapidosa mesotrophica

673

NW 325°

22°

Nýdek 3

N 49°39.709 E 18°48.030

103

mesotrophica

601

S 165°

30°

Písek 1

N 49°34.709 E 18°48.951

95

lapidosa mesotrophica, mesotrophica

650

W 265°

15°

Písek 2

N 49°35.156 E 18°49.794

114

lapidosa mesotrophica, lapidosa acidophila

753

SW 225°

20°

Písek 3

N 49°34.304 E 18°49.964

82

mesotrophica

549

SE 50°

25°

Písek 4

N 49°35.551 E 18°48.973

120

mesotrophica

759

SW 205°

18°

Horní Lomná 1

N 49°30.422 E 18°38.367

101

mesotrophica, lapidosa mesotrophica

765

SE 135°

15°

Horní Lomná 2

N 49°30.821 E 18°36.721

115

mesotrophica

794

SW 310°

13°

Plot

Results On the basis of comparisons of mean annual ring curves for particular plots in all three districts, their high similarity was evident. Thanks to the similarity, it was possible to compile standard annual ring chronologies for particular districts. From the regional standard annual ring chronology at the Nýdek district, an increase of the radial increment was evident in the second half of the 1990’s, which was interrupted in 2000. A two-year period follows with an increased radial increment, which was interrupted again in 2003 and subsequently in 2006 (Fig. 1A–1D). In forest districts Písek and Horní Lomná (Fig. 1B, 1C), a decline is evident in the radial increment from the beginning of the 1970’s to the first half of the 1990’s of the 20th century. The development in recent ten years is similar to the Nýdek district (Fig. 1A). The course of a mean curve for the whole area (Fig. 1D) approaches most the Písek district (Fig. 1B). The years with low radial increments were confirmed by the analysis of negative pointer years (Tab 2). The correlation of diameter increment with mean monthly temperatures and precipitation shows above all positive statistically significant correlations. The diameter increment significantly positively correlates with precipitation in September of the previous year (Nýdek – Fig. 2A, Písek – Fig. 2B, the group of all three districts – Fig. 2D) and precipitation in June of the current year (Nýdek – Fig. 2A, Písek – Fig. 2B, the group

Altitude Exposition Slope m (slope orient.) inclination

of all three districts – Fig. 2D). The growth of spruce also significantly correlates with temperatures in October of the previous year (Písek – Fig. 3B, Horní Lomná – Fig. 3C), in March of the current year (Nýdek – Fig. 3A, Písek – Fig. 3B, Horní Lomná – Fig. 3C, the group of all three districts – Fig. 3D) and April of the current year (Horní Lomná – Fig. 3C). The negative statistically significant correlation of increment was determined for temperatures in September of the previous year (Písek – Fig. 3B). Discussion and conclusions Based on the standard annual ring chronology, gradual decreasing the radial increment is evident from the beginning of the 1970’s to the end of the first half of the 1990’s of the 20th century. The cause of this decline consisted very probably in heavy air pollution load, namely SO2 air pollutants in the 1970’s of the 20th century in combination with climatic factors. This period was also critical for spruce growth in the Krušné hory Mts. (Kroupová 2002), Polish Western Beskids (Wilczyński and Feliksik, 2005) and later for the Jizerské hory Mts. and Krkonoše Mts. (Kroupová 2002). Negative effects of air pollutants on the increment were repeatedly proved (e.g. Feliksik, 1995; Juknys et al. 2002). In the second half of the 1990’s of the 20th century, the gradual increase of the radial increment follows being interrupted in 2000. This

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A

Nýdek

Annual ring width [0.01 mm]

300 250 200 150 100 50 0 1969

1974

1979

1984

1989

1994

1999

2004

1999

2004

1999

2004

1999

2004

Position of curves [years]

Písek

B 300


250 200 150 100 50 0 1969

1974

1979

C

1984 1989 1994 Position of curves [years]

Horní Lomná


180 160 140 120 100 80 60 40 20 0 1969

1974

1979

D

1984 1989 1994 Position of curves [years]

Silesian Beskids


250 200 150 100 50 0 1969

1974

1979

1984

1989

1994

Position of curves [years]

Fig. 1: Regional standard chronologies for particular districts (A – Nýdek, B – Písek, C – Horní Lomná) and the whole monitored area (D – Silesian Beskids). Grey line = plots (A, B, C) or districts (D), black line = average.


Tab. 2: Negative pointer years 1969

1982

1995

1970

1983

1996

1971

1984

1997

1972

1985

1998

1973

1986

1999 2000

1974

1987

1975

1988

2001

1976

1989

2002

1977

1990

2003

1978

1991

2004

1979

1992

2005

1980

1993

2006

1981

1994

2007

legend: 1988 – Negative pointer year for the group of all three districts 1970 – Negative pointer year only for the Nýdek district 1979 – Negative pointer year only for the Písek district 1996 – Negative pointer year only for the Horní Lomná district Negative pointer year which was found for two districts are also negative pointer years for the group of all districts (complex of all data).

period was characterized by temperate winters without temperature extremes, high temperatures in the growing season, more or less normal precipitation and also by the decline of air pollution. An obvious increase in the increment of spruce was documented by Wilczyński and Feliksik (2005) in the Polish Western Beskids for the same period. The two-year period of an increased radial increment followed being interrupted again in 2003 and 2006. The course of regional standard chronologies from our monitoring is in principle consistent with findings of Šrámek et al. (2008) from the same area. Aer confrontation negative pointer years (Tab. 2) with climatic data it is possible to deduce effects of the lack of precipitation on growth – particularly 1976 and 2003 were extremely dry. Drought in 2003 was evaluated as150-year and generally the second most important in the CR aer the year 1947 while drought in 1976 was evaluated as the third (Možný 2004). The course of precipitation in 2003 is commented below. In 1976 in the Jablunkov area, it referred to very low precipitation in the period FebruaryApril and further to low precipitation in June. The year was markedly subnormal also in the total annual precipitation. Markedly dry were also

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next two negative pointer years 1992 and 1993. The period 1989–1993 was the driest five-year period in the CR from 1876 (Blinka 2004). In the Jablunkov area, it referred particularly to the marked fall of summer precipitation (MayAugust). In 1993, it referred also to autumn precipitation (September-November). Also summer 2004 was precipitation-subnormal, namely May and July to September. In 1980 and 2006, the interaction of temperatures and precipitation was decisive in the key spruce growth periods of the year. In 1980, low temperatures from March to May connected with subnormal precipitation in March and May were essential. The combined effect of high temperatures and low precipitation in 2006 is commented below. Similar results were noted in the region of the Orlické hory Mts. (Rybníček et al. 2009). There is coincidence in the negative pointer years: 1971 (the Orlické hory Mts. and Horní Lomná), 1974 (the Orlické hory Mts. and Horní Lomná), 1980 (the Orlické hory Mts. and the Silesian Beskids), 2003 (the Orlické hory Mts. and the Silesian Beskids). Interpretation by the correlation of radial increment of the regional standard chronology with mean monthly temperatures and precipitation is partly evident and partly rather complicated. The positive effect of precipitation in September of the previous year (Fig. 2A, B, D) can be interpreted by the creation of a sufficient supply of water in soil at the end of the growing season. Sufficient soil moisture is important for the creation of storage substances and thus also for the initial stage of the creation of annual rings in the following year. The positive effect of precipitation on growth was detected also in Poland at Forest District Bukowiec. It referred to the radial growth and precipitation correlation for the whole growing season (April – September) and correlation with winter precipitation (Feliksik 1993). The soil moisture can be also linked with the negative correlation of temperatures in September of the previous year and increment found in Forest District Písek (Fig. 3B) – high temperatures in September result in soil desiccation (already insufficiently covered by undergrowth). This negative correlation was also determined at the analysis of data set of 22 spruce and pine plots ICP Forests (Mze ČR, VÚLHM 2004); the negative effect of high temperature in summer and at the beginning of autumn (June – September) of the previous year was also noted by Feliksik (1993). The positive effect of June precipitation on radial growth in the current year (Fig. 2A, B, D) is

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A

Nýdek 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0

-0.1 -0.2 -0.3

B

Písek 0.6 0.5 0.4 0.3 0.2 0.1 0

-0.1 -0.2

C

Horní Lomná

0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 -0.05 -0.1 -0.15 -0.2

D

Silesian Beskids

0.6 0.5 0.4 0.3 0.2 0.1 0 -0.1 -0.2

Fig. 2: Values of correlation coefficients of the regional residual index annual ring chronology with mean monthly precipitation of May of the previous year to August of the current year for the period 1969–2001. Black coloured values are statistically significant ( = 0.05). A – Nýdek, B – Písek, C – Horní Lomná, D – Silesian Beskids.


A

7

Nýdek 0.5 0.4 0.3 0.2 0.1 0

-0.1 -0.2 -0.3 -0.4

B

Písek 0.5 0.4 0.3 0.2 0.1 0

-0.1 -0.2 -0.3 -0.4

C

Horní Lomná 0.6 0.5 0.4 0.3 0.2 0.1 0

-0.1 -0.2 -0.3 -0.4

D

Silesian Beskids 0.5 0.4 0.3 0.2 0.1 0

-0.1 -0.2 -0.3

Fig. 3: Values of correlation coefficients of the regional residual index annual ring chronology with mean monthly temperatures from May of the previous year to September of the current year for the period 1969–2001. Black coloured values are statistically significant ( = 0.05). A – Nýdek, B – Písek, C – Horní Lomná, D – Silesian Beskids.

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an expected effect belonging to the most oen proved correlations. In June and July, significant part of the total annual increment is created. Thus, if sufficient water supply and, at the same time, also favourable temperatures occur, it reflects markedly in the radial increment. Positive correlations of summer precipitation and radial increment documented Feliksik et al. (1994) from the Polish part of the Beskids for June and July and Desplanque et al. (1999) from lower locations of the French Alps for May to July. The growth of spruce is also significantly positively affected by temperatures in March of the current year (Fig. 3A–D) and in case Forest District Horní Lomná by temperatures in April (Fig. 3C). In this season, spruce regenerates its photosynthetic capacity. According to Bergh, Linder (1999), this regeneration is particularly affected by average air temperatures and the presence of heavy night frosts. Another possible explanation of the relationship can consist in the earlier thawing of soil (and thus higher soil temperature). The earlier thawing affects the regeneration of photosynthetic activities and provides also better availability of water for tree roots at the beginning of cambial activities in May. Relationships of March temperatures with increments were also determined from the ICP Forests data (MZe ČR, VÚLHM 2004) just for areas in forest regions of the Sub-Beskids Upland (the Podbeskydská vrchovina Upland) and the Moravian-Silesian Beskids. The positive effect of spring temperatures has been already documented in the cited survey from the Polish Beskids (Feliksik et al. 1994), viz. for the period March-May. The explanation of positive correlation between temperatures in October of the previous year and increment determined in Forest Districts Písek and Horní Lomná (Fig. 3B, C) is rather complicated. At first sight, this relationship is in contradiction with the above-mentioned negative correlation for September and for its interpretation. Of course, it is necessary to take into consideration that October temperatures are mostly 3–5 °C lower and that they mostly do not result in the excessive desiccation of soil. Higher mean temperatures in October can rather point to more balanced temperatures without sudden declines and thus to the more fluent and grad-

ual transition of spruce to dormancy (including more favourable conditions for the allocation of nutrients). The turn from the negative correlation of temperatures and increments to positive correlations from September to October (although it did not refer to statistically significant correlations) was found both at dendrochronological surveys in the Orlické hory Mts. (Rybníček et al. 2009) and at the processing of data set of 22 spruce and pine plots ICP Forests (MZe ČR, VÚLHM 2004). The dendrochronologial data confirm a hypothesis on the important role of the climatically unfavourable year 2003 for spruce decline in the Silesian Beskids. Aer the fall of increments in 2003, trees did not reach increments from the period 1997–2002. Another marked fall occurred in 2006. In the same period, symptoms of the decline of stands were more intensive and the mortality of stands increased. The year 2003 was markedly dry and warm. Extremely low precipitation in February was the beginning of the water deficit in soil, the deficit of precipitation continued in spring months and virtually throughout the growing season and extremely particularly in June and August. At the same time, above-average temperatures occurred (particularly in May, June and August), which, together with lower air humidity, resulted in the intensive soil desiccation. In 2006, the extreme deficit of precipitation in combination with highly above-average temperatures (nearly 5 °C higher mean temperatures in July than a long-term normal in 1961–1990) showed a decisive role. Repeated spells of drought decreased the adaptation potential of Norway spruce stands and markedly reflected in their increments. This effect can be evaluated as a predisposition effect before 2003. Dry and warm weather in 2003 can be consider as the initiation stressor showing the substantial or even key role in the present health condition of stands. Acknowledgement The paper was prepared within the Czech Terra VaV SP/2d1/93/07 project of the CR Ministry of Environment.


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