The Causes of Tropical Deforestation in Ecuador: A ... - Science Direct

World Development, Vol. 19, No. 9, pp. 1145-1151, 1991. Printed in Great Britain.

0305-750X/91 $3.0t) + 0.110 © 1991 Pergamon Press plc

The Causes of Tropical Deforestation in Ecuador: A Statistical Analysis D O U G L A S S O U T H G A T E , R O D R I G O SIERRA, and LAWRENCE BROWN* Ohio State University, Columbus - - This paper reports a statistical analysis of the causes of agricultural colonization and land clearing in eastern Ecuador. The results bolster many of the arguments that have been made about the social forccs driving I~ropical deforestation. In gcneral, the prospect of capturing agricultural rents stimulates settlement of tree-covered hinterlands. Accordingly, the presence of roads and urban centers attracts rural settlement. Colonists also prefer to go where soils are suitable for crop or livestock production, all else remainiug the same. In addition to being a function of population pressure, the extent of land clearing is shown to be a consequence of tenure insccurily. These results suggest that institutional reform is nccdcd to encourage conservation of tropical forests.

Summary.

1. I N T R O D U C T I O N W i d e s p r e a d c o n c e r n o v e r the impacts of tropical d e f o r e s t a t i o n has s t i m u l a t e d e x a m i n a t i o n of the factors inducing people to settle a n d clear t r e e - c o v e r e d h i n t e r l a n d s in the T h i r d World. For the most part, r e s e a r c h e r s have u n d e r t a k e n case studies, analyzing individual frontier c o m m u n ities' r e s p o n s e s to a variety of g o v e r n m e n t a l policies a n d m a r k e t forces ( M a c d o n a l d , 1981; M o r a n , 1983: R u d e l , 1983; Lisansky, 19891. While this a p p r o a c h yields valuable insights, a series of case studies does not constitute a solid basis for assessing the relative s t r e n g t h of the various forces responsible for d e f o r e s t a t i o n . T h a t kind of a s s e s s m e n t requires an analysis with an e x p a n d e d g e o g r a p h i c focus. T h e r e s e a r c h r e p o r t e d in this p a p e r addresses this n e e d . O u r study of the causes of tropical deforestation was conducted in eastern E c u a d o r ' s A m a z o n i a n lowlands. W o r k i n g with data collected in a large area has allowed us to use statistical analysis, r a t h e r t h a n a case study a p p r o a c h . T h a t analysis is well suited to clarifying relationships a m o n g hind clearing, rural p o p u l a t i o n pressure, local d e m a n d for agricultural c o m m o d i t i e s , i n f r a s t r u c t u r e d e v e l o p m e n t , a n d t e n u r e insecurity. T h e p a p e r begins with a brief description of the study area. Basic f e a t u r e s of the physical env i r o n m e n t are n o t e d , as are characteristics of the h u m a n p o p u l a t i o n . Next, a m o d e l explaining tropical d e f o r e s t a t i o n is p r e s e n t e d . A f t e r that,

data used to e l a b o r a t e the model are described a n d the results of regression analysis are s u m m a r ized. W e c o n c l u d e with a discussion of the n e e d s for additional research as well as the implications of this study for policy g o v e r n i n g the developm e n t of the A m a z o n basin.

2. E A S T E R N E C U A D O R ' S A M A Z O N I A N LOWLANDS With 26,266,000 ha of territory on the S o u t h A m e r i c a n m a i n l a n d a n d 801,000 ha in the Galapagos Islands, E c u a d o r (Figure 1) is slightly larger t h a n the f o r m e r West G e r m a n y or the state of C o l o r a d o . N e v e r t h e l e s s , its g e o g r a p h y is astonishingly wtried. T h e coastal plain, or littoral, e n d s a b r u p t l y 150-200 kill inland from the Pacific O c e a n . Nestled in the A n d e s , which are d o m i n a t e d by volcanoes rising as m u c h as 6,310 m a b o v e sea level, are t e m p e r a t e i n t e r m o n t a n e valleys. B e y o n d the e a s t e r n range of the A n d e s , a rapid descent into the A m a z o n i a n rainforest of *The authors thank the Jesse Smith Noyes Foundation for supporting Mr. Sierra',', graduate studies and the Graduate School of Ohio State University for providing funds to complete the research described ill this paper. Also, Mr. Roberto U[Ioa greatly facilitated data collection in Ecuador and Profs. Paul Colinvaux, Earl Epstein, and John Lyon of ()hit) State University provided many useful insights to the authors, who arc, of course, responsible for all errors and omissions ill this paper.

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0

0

,¢o~

50 k .

provincial boundary

duction around Nueva Loja, began during the 1970s. Improved infrastructure, in turn, has stimulated rapid settlement. Between the 1974 and 1982 censuses, 92,700 individuals moved into Ecuador's four eastern provinces. The 1982 census reveals that a relatively small part of the labor force found employment in the oil industry or in the rapidly expanding service and construction sector. Instead, 611% of the region's economically active population worked in agriculture (INEC, 1985). With the agricultural population expanding rapidly, there has been substantial deforestation in the Oriente. For example, although forests continue to cover well over half of northeastern Ecuador, 36% of the region has been claimed by agricultural colonists, all of whom arc clearing land (MAG, 1987: Brown et al., 19921.

Figure 1. Map of Ecuador and study area.

3. A M O D E L OF T i l E CAUSES OF TROPICAL DEFORESTATION

the Oriente begins. An Amazonian frontier town, Nueva Loja (formerly called Lago Agrio) is only 400 km from the Pacific and 300 m higher than the surface of the Atlantic Ocean, which is 3,0011 km due east. In Ecuador, dramatic topography is matched by climatic and biological diversity. Twenty-five of the 30 life zones identified by Holdridge (1967) are found in the country (Cabarle e t a l . , 1989, p. 5). In addition, the number of plant and animal species living in or endemic to Ecuador approaches similar counts for larger countries in the Western hemisphere (Cabarle et al., 1989). Nowhere are natural resources more varied than in the Amazonian lowlands of the country's four eastern provinces. Regardless of former President Plaza Lasso's warning that "the Oriente is a myth," many Ecuadorians and their political representatives continue to think that the eastern part of their country has great agricultural potential. Certainly, climatic conditions are promising. Average temperatures vary from 20°C to over 24°C and precipitation is plentiful throughout the year. Ongoing surveys of the Oriente, however, indicate that limited soil fertility, and poor drainage render sustained crop production uneconomical in most of the region. In 1987, the Ministry of Agriculture and Livestock concluded that no more than 16'7o of northeastern Ecuador should be in cropland or pasture (MAG, 1987). Agricultural colonization of the Oriente was confined to a few lower Andean valleys until the late 1960s. Exensive road construction in the region, undertaken primarily to service oil pro-

Although population growth and deforestation are closely related, land clearing is not an exclusively demographic phenomenon. As Bromley and Cernea (19891 point out, tangible environmental problems in the developing world, including tropical deforestation, are often a manifestation of underlying institutional crises. A crisis is obvious when public sector claims on forests far outstrip the government's capacity to manage "its" properties. In Ecuador, for example, practically all tree-covered land is designated as "forest patrimony" or national parks. The government's effective control of that land is negligible, however. No rangers work in the 211(111,000 ha of forest patrimony delimited in the northwest and northeast (MAG, 1987) and, as of 1987, a mere two administrators, 25 technicians, and 119 permanent and seasonal rangers had been assigned to the 2,111(1,000 ha of parks in continental Ecuador (DINAF, 19881. A discrepancy between public sector claims on forests and limited governmental capacity to control access would normally bring about what Hardin (1968) calls a "tragedy of the commons." That is, individuals encroaching on the forest patrimony or national parks (e.g., to collect fuelwood) would neglect the costs society as a whole associates with forest degradation. Tacitly recognizing this, Ecuador's government allows individuals and firms to make claims on treecovered land. Private parties interested in timber management, however, cannot acquire forests: logging concessions were banned in 1982. Instead, formal property law, as executed by the Ecuadorian Institute for Agrarian Reform and

CAUSES OF TROPICAL DEFORESTATION Colonization ( I E R A C ) , has required that those settling in tree-covered hinterlands, clear their respective parcels in order to acquire formal property rights. This tenurial regime induces a cycle of excessive land clearing and inadequate soil conservation in the vicinity of agricultural frontiers (Southgate, 1990). In addition, bureaucratically induced tenure insecurity contributes to deforestation. Like other land reform agencies established during the era of the US-sponsored Alliance for Progress, I E R A C requires a long time, often years, to adjudicate claims for formal property rights. Delays are explained in part by administrative constraints; I E R A C ' s recordkeeping system is cumbersome and the agency did not acquire its first computer until the late 1980s. Furthermore, the complexity of formal property law lengthens the adjudication process; I E R A C is obliged to execute 10 separate procedures during the course of settling a tenure claim (Seligson, 1984). In the face of tenure insecurity, which is especially severe for those who lack the funds or influence needed to "move the system along," agricultural colonists in the Amazon basin tend to safeguard land claims by continuously using their parcels for crop or livestock production (Rudel, 1983). Indigenous groups respond identically to the same institutional incentives. Macdonald (1981) reports, for example, that the periodic fallowing scheme long practiced by the Amerindian community of Pasu Urcu, in eastern Ecuador, was abandoned during the 1970s after I E R A C agents informed the community that fallow lands could be claimed by agricultural colonists, who were 50 km away at the time. For colonists as well as indigenous inhabitants, then, continuous agricultural production is a way to assert and to protect property rights. To describe the demographic and institutional forces responsible for deforestation, our model treats settlement in tree-covered hinterlands and land clearing as two separate activities. (a) Agricultural colonization Because frontier tenure regimes impair the ability of individuals and firms to collect forestry and other nonagricultural income, settlement in tree-covered hinterlands is stimulated by the prospect of capturing agricultural rents. That is, there is a direct and positive relationship between demographic pressure at any particular site and agricultural (as opposed to nonagricultural) rents at the same site. Agricultural rents and, hence, settlement are

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an increasing function of three factors: the scale of nearby urban development, soil productivity, and access to outside markets. The presence of cities and towns enhances agricultural income by strengthening local demand for crops and livestock. Soils underlying tropical forests are usually infertile and often erodible (Nicholaides et al., 1983), however, which tends to impede agricultural colonization. Finally, improved access is critical for agricultural development in developing country hinterlands. For example, Bromley (1981) points out that primary forests covered most of northwestern and northeastern Ecuador before all-weather highways were constructed in those two regions. These influences on agricultural rents are expressed by the three right-hand side terms of the first regression in our model, which explains the extent of agricultural colonization in the 20 cantons of the four provinces in eastern Ecuador: A G P O P = bl0 + bit U R B P O P + b12 SOILS + bj3 R O A D S , (I) where: AGPOP

= the canton's agricultural labor force, U R B P O P = the canton's urban population, SOILS = hectares in the canton covered with soils that do not have major limitations for crop production, and ROADS = kilometers of all-weather roads in the canton.

A G P O P is an indicator of rural population pressure. As indicated above, the size of the canton's urban population, URBPOP, is a satisfactory proxy for local demand for agricultural products. Discussed in the next section are the criteria used to measure the variable SOILS. The extent of all-weather roads in a canton, R O A D S , indicates the canton's accessibility. Regression coefficients bll through bL~ are" all expected to be positive. Some explanation of the exogeneity of the three factors influencing agricultural rents is in order. Urban expansion in the Amazon basin tends to be weakly related to agricultural production in the surrounding countryside. The growth of northeastern Ecuador's towns, for example, has been closely linked to petroleum industry development. At an extreme, the large size of Manaus, Brazil is explained by its status as a duty-free zone, which has greatly stimulated industrial development. Given this characteristic of urban development in the region, it is appropriate to treat U R B P O P as exogenous in equation (1).

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The second right-hand side variable in equation (1) is i n d e p e n d e n t because the natural capacity of land to support crop or livestock production is beyond human control. The history of the A m a z o n basin generally and eastern E c u a d o r specifically demonstrates that the penetration of highways into forested hinterlands usually leads to agricultural colonization, not vice versa. The g o v e r n m e n t s of Brazil and o t h e r countries have constructed roads more to establish " h u m a n frontiers,'" which safeguard territorial claims, than because they are convinced of the A m a z o n basin's great agricultural potential (Landau, 1980). Settlement of northeastern E c u a d o r began in earnest only after infrastructure had improved, following the discovery of p e t r o l e u m in the region (Bromlcy, 1981). Brazilian and Ecuadorian experience confirms that the wlriable R O A D S can be treated as exogenous in this analysis. (b) L a n d clearing The second equation of tile regression model reflects the institutional environnlent facing settiers in the A m a z o n basin. That is, it relates tile extent of land clearing in a canton, D E F O R , to d e m o g r a p h i c pressure (specifically, the first e q u a t i o n ' s d e p e n d e n t wlriable) as well as to a non-negative index of relative tenure security, TENSEC: D E F O R = b > + bel A G P O P + h~.2 T E N S E ( ' . (2) A G P O P ' s coefficient, bel, is expected to be positive. T E N S E C is constructed so as to indicatc differences in formal tenure security a m o n g cantons: TENSEC adjudicated % of a canton's agricultural land adjudicated % of agricultural hind in study area (3) If the wtlue of T E N S E C for any particular canton were greater than 1.00, then that canton's farmers would be more likely than others in eastern E c u a d o r to have lk)rmal tenure. Conversely, a wdue less than 1.00 indicates that a canton's farmers are less likely to have formal tenure. T E N S E C ' s coefficient bee, is expected to bc negative because enhancing formal tenure security reduces the need for continuous exercise of informal agricultural use rights. Because the pace of land adjudication in different parts of thc country is the prerogative of the national governmerit, T E N S E C is an exogenous variable. Arguably, tenure security could influence far-

mers" Iocational decisions, t t o w e v e r , the correlation between A G P O P and T E N S E C is only 0. 133. Accordingly, it is reasonable to conclude that formal tenure security influences colonists' resource d e v e l o p m e n t decisions (i.e., choices about hind clearing) once they have settled m a particular area. Cohmization itself is driven by forces expressed in equation (1).

4. D A T A The first equation's d e p e n d e n t w m a b l e , A G P O P , and one of its independent variables, U R B P O P , were obtained from a 100% sample of individual returns collected in eastern E c u a d o r during the country's most recent census, conducted by the National Institute for Statistics and the Census ( I N E C ) in 1982. The agricultural labor force was found to be highly correlated with other measures of settlement in the countryside (e.g. rural population or rural employment), Similarly, urban population is highly collinear with other proxies for local demand for agricultural conlmodities (e.g., nonagricultural work force). Thc variable S O I L S , which equals thc area in each canton with " g o o d " agricultural potential, was assessed through interpretation of soil maps prepared by the National Program for Agrarian Regionalization ( P R O N A R E G ) . Recognizing the principal environmental constraints on crop and livestock production in eastern Ecuador, wc classified the region's soils according to drainage and fertility. Our procedurc yielded results very similar to those obtained by the country's National Developnlcnt ('ouncil ( C O N A D I : . ) and the Unitcd Nations E n v i r o n m e n t a l Program (tINEP), which also relied on P R O N A R E G maps. Whereas C O N A D E - U N E P (1986) found that 5.69% of eastern Ecuador is suitable for agriculture, we d e t e r m m e d that 5.04% of the same region was free of serious drainage or fertility problems. Road maps prepared by INE(" as well as an inventory conlpleted by thc Ministry of Public Words ( M O P , 1987) were used to detcrnline how nlany kihmletcrs of all-weather roads existed in each canton in 1982. Tile National Institute for tile Colonizathm ol tile Ecuadorian Anlazon ( I N C R A E ) and the C e n t e r for Integrated h w e n t o r y of Natural Resources (('I+IRSEN) have used aerial photographs and satellite inlages to assess land use change in different parts of eastern Ecuador between 1977 and 1985 ( I N C R A E - ( ' I A R S E N , 1987). The results of that study allowed us to calcuhttc the extoll! of tropical deforestation in

CAUSES OF TROPICAL DEFORESTATION the early 1980s (i.e., the second equation's dependent variable) in 11 of eastern Ecuador's 20 cantons. No such estimates are available for the other nine cantons. Finally, records showing cumulative land adjudication in eastern Ecuador were collected from IERAC. Those records, along with INCRAE land use data, were used to determine the index, TENSEC, for each canton. Correlations among each regression equation's right-hand variables are, in general, quite low. The major exception is the 0.636 coefficient for URBPOP and ROADS, which is understandable since urban settlement is rare where all-weather roads have not yet penetrated. Collinearity between the two variables impedes reliable estimation of their respective standard errors. As indicated above, the two right-hand variables in equation (2), which explains land clearing, are not collinear.

5. R E G R E S S I O N RESULTS Equations (1) and (2) comprise a recursive system of regressions. Koutsoyiannis (1977, pp. 340-342) points out that ordinary least squares (OLS) estimates of such a system's coefficients are efficient. OLS estimation of equation (1), which explains agricultural settlement, yields the following results (standard deviations are shown in parentheses): AGPOP = +

469.144 + 0.263 URBPOP (251.334) (0.061)

0.008 SOILS + 3.350 ROADS (0.002) (2.527)

F = 26.856

adj R 2 = 0.803

n = 20.

In spite of limited degrees of freedom, applying the F-test with a 99% confidence interval leads to rejection of the hypothesis that all regression coefficients equal zero. This test result is consistent with the hypothesis underpinning this equation, that the prospect of capturing agricultural rents stimulates colonization of forested hinterlands. At the same time, application of a t-test with a 99% confidence interval leads to rejection of the null hypothesis for the coefficients of the first two right-hand variables. The somewhat lower t-statistic for the coefficient of ROADS is possibly explained by multicollinearity between that variable and URBPOP. The signs of the right-hand coefficients are all positive, as expected. OLS regression of the second equation, which

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explains land clearing, yields the following resuits: DEFOR = F = 36.097

16,111.728 + 51.073 A G P O P (23,977.621) (6.241) 26,989.394 TENSEC (12,321.915) adj R z = 0.875

n = 11.

Applying the F-test with a 99% confidence interval leads to rejection of the hypothesis that the right-hand coefficients of equation (2) all equal zero. A G P O P ' s and TENSEC's coefficients are positive and negative, respectively, as expected. A G P O P ' s coefficient is significantly different from zero when a 99% confidence interval is used. If a confidence interval of 94% or less is used, then TENSEC's coefficient is also significantly different from zero. The preceding estimates of regression coefficients are efficient. Had a larger sample been available, then confidence intervals around true coefficient values would have been smaller. In particular, more conclusive testing of the significance of TENSEC's coefficient would have been possible. Also, the problem of multicollinearity is frequently addressed by using a larger sample. Consequently, high covariance between U R B P O P and ROADS, which might explain acceptance of the null hypothesis for the latter's coefficient, might be symptomatic of the small sample used in this research. In spite of the small data set available to us, the preceding results of regression analysis provide conclusive evidence about the causes of tropical deforestation.

6. DISCUSSION To date, case studies have constituted the principal point of empirical reference for discussions of the causes of tropical deforestation. That literature provides useful insights into the market forces and public policies that induce the clearing of tree-covered land near the equator. However, a series of case studies alone does not constitute a satisfactory basis for general statements about linkages among land clearing, tenure security, rural population pressure, and the factors influencing agricultural rents. The research reported in this paper constitutes a methodological departure from previous analyses of the causes of tropical deforestation. We have shown that statistical analysis can indeed clarify the human context of land clearing and resource management across broad stretches of an agricultural frontier. Our results bolster the

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argument that settlement of forested hinterlands is driven by the prospect of collecting agricultural rents. In addition, it suggests that deforestation is a consequence of demographic pressure. Deforestation also occurs as colonists attempt to safeguard their tenuous legal hold on frontier lands. These results, obtained with a small sample, should encourage parallel research with the larger data sets that can be assembled in other countries. Also, as r e m o t e sensing technology advances, it will be possible to undertake this type of analysis with samples comprising smaller geographic units. In and of itself, however, our analysis yields insights for policy making. D e v e l o p i n g country governments can do two things to resolve the institutional crises contributing to tropical deforestation. First, they can streamline tenure adjudication procedures. If this is done, people living in tree-covered hinterlands will no longer be obliged to deplete resources just to safeguard weak property rights. Second, land clearing should no longer be a prerequisite for formal tenure. W h e r e land clearing is a prerequisite, no one has a clear right to the income associated

with forest conservation. Consequently, everyone is obliged to respond immediately to any opportunity to capture the rents generated by land use conversion (Southgate, 199(/). Location theory informs us that where there are nonattenuated property rights agriculture's extensive margin is flmnd where per-hectare agricultural rents equal per-hectare rents associated with forestry or other alternative land uses (Southgate, 1990). Unfortunately, property rights attenuation is the norm in Latin America. Tenure insecurity is a problem in all countries with extensive tropical forests. In these countries, property rights are a reward for land clearing, as Mahar (1989) documents for the case of Brazil. U n d e r these circumstances, the relationship among agriculture's extensive margin, property rights, and rents associated with different land uses cannot be determined. While this paper's analysis furnishes no specific insights into the likely impacts of institutional reform in Ecuador or any other country, it nevertheless bolsters the argument that institutional crisis contributes significantly to deforestation in tropical America.

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Rudel, T., "'Roads, speculators, and colonization in the Ecuadorian Amazon," Human Ecology, Vol. 11, No. 4 (1983), pp. 385-403. Seligson, M., "'Land tenure security, minifundization, and agrarian development in Ecuador," Mimeo (Quito: USAID, 1984). Southgate, D., "'The causes of land degradation along expanding agricultural frontiers in the Third World,'" Land Economics, Vol. 66, No. 1 (1990), pp. 93-101.