The aim of this work was to characterize the spatial and temporal dynamics of the transformation of the natural cover in the Dry Chaco ecoregion from 1976 to 2012. Dry forests in this region have one ...of the highest deforestation rates in the world. We analyzed 44 Landsat scenes, including part of Argentina, Paraguay and Bolivia. The analysis was based on tracking individual transformed plots of the entire Dry Chaco region for over more than three decades using the same protocol. Until the end of 2012 15.8 million ha of the original habitats of the Chaco were transformed into croplands or pastures. Our study showed that the greater annual rates of transformation were observed in Paraguay, where deforestation increased dramatically in the last decade, reaching values higher than 4.0% in 2010, the highest historical value in the entire region. The size of the transformed plots increased significantly through the studied period both in Argentina and Paraguay, while in Bolivia decreased. At the landscape level, the use of several fragmentation indices showed the disruption of the continuity and connectivity of the original vegetation. The spatially explicit description of the dynamics of transformed areas is an indispensable tool for natural resources management, territorial planning and deforestation impacts assessment. The developed geo-database is available online at http://monitoreodesmonte.com.ar/ for further analyses and use.
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•We generated a geo-database of the natural cover transformation in Dry Chaco.•We analyzed the deforestation patterns at plot and landscape level.•The transformed area in Dry Chaco by the end of 2012 totalized 15.8 million ha.•Annual Rates of Transformation were intensified from 1976 to 2012 at country level.•Paraguay showed an exponential increase in the Annual Rate of Transformation.
Conflicts over land use and ownership are common in South America and generate frequent confrontations among indigenous peoples, small-scale farmers, and large-scale agricultural producers. We argue ...in this paper that an accurate identification of these conflicts, together with a participatory evaluation of their importance, will increase the social legitimacy of land use planning processes, rendering decision-making more sustainable in the long term. We describe here a participatory, multi-criteria conflict assessment model developed to identify, locate, and categorize land tenure and use conflicts. The model was applied to the case of the “Chaco” region of the province of Salta, in northwestern Argentina. Basic geographic, cadastral, and social information needed to apply the model was made spatially explicit on a Geographic Information System. Results illustrate the contrasting perceptions of different stakeholders (government officials, social and environmental non-governmental organizations, large-scale agricultural producers, and scholars) on the intensity of land use conflicts in the study area. These results can help better understand and address land tenure conflicts in areas with different cultures and conflicting social and enviornmental interests.
Dry forests are among the most threatened ecosystems globally, due to agricultural expansion driven by the increasing demand for food, fibers, and energy in developed and emerging countries. Among ...these, the forests of the South American Gran Chaco are one of the global deforestation hotspots. The Argentine Dry Chaco has been the focus of several studies that assess the factors that drive forest conversion. However, these studies do not describe the causal relationships among these drivers and seldom use existing theory to select drivers. Here we employ a theory-driven approach to test the relative merits of alternative and complementary hypotheses to explain the drivers and mechanisms explaining the unequal spatial distribution of forest loss and maintenance in the Argentine Dry Chaco from 2000 to 2010. Using structural equation modeling, we quantified the direct and indirect effects of multiple drivers and compared the explanatory power and parsimony of these alternative hypotheses, i.e. the biophysical, infrastructure, socio-demographic, institutional, and the integration of them. For both forest loss and maintenance, the model containing infrastructural drivers had the best balance between parsimony and explanatory power. Integrated models, comprising a combination of drivers, had the highest explanatory power (R2 = 0.81 for forest maintenance, and R2 = 0.58 for forest loss). We show that biophysical constraints operate directly and indirectly: soil suitability had direct effects on forest cover maintenance, while precipitation affected it both directly and indirectly through influencing the institutional (land tenure) and infrastructure (road density). Indigenous communities positively affected forest maintenance both directly and indirectly mediated by non-private land tenure. Our results suggest that disentangling the structure of the relationships among drivers could increase our capacity for understanding and steering land-use change. Furthermore, policies for halting deforestation might increase their effectiveness by accounting for the mechanisms that underlie forest loss and maintenance.
•We assessed the drivers of forest cover change in the Argentine Dry Chaco through structural equation modeling.•Our findings support the agricultural adjustment hypothesis.•In the Argentine Dry Chaco, agglomeration economies might be influenced by land privatization.•Our study supports the neoliberal frontiers hypothesis since demography is a consequence rather than a cause of deforestation.•Overall, assessing indirect effects increased the capacity to understand forest cover change.
The expression Forest Transition (FT) and Ecological Transition (ET) were coined to describe the recovery path of forested areas (or more general natural vegetation) after heavy conversion into ...croplands. FT/ET would be driven by two main socio-economic controls: a) agricultural intensification in the most productive areas and the simultaneous reduction of cropped area in the less suitable areas (land-sparing); and b) rural population migration from rural to urban areas. In the argentine portion of the Semiarid Chaco a rapid and extensive clearing for industrial agriculture and cattle ranching based on sown pastures is taking place. In this article we evaluated the occurrence, magnitude and localization of FT/ET in the argentine portion of the Semiarid Chaco during the 1977–2007 period using an approach based on remotely sensed data. From land cover maps we derived three diagnosis variables of FT/ET: (1) the area of natural vegetation at the end of the study period; (2) the rate of annual clearance (natural vegetation loss) for the whole period; and (3) the temporal change of the area of natural vegetation in the last portion of the study period. The diagnosis variables were combined to derive 12 classes (landscape types). We observed a systematic loss of the surface occupied by natural vegetation. Industrial agriculture grew in aggregated patches generating a homogenization of the landscape. In only a 4.8% of the study area we observed a pattern of change compatible with a FT/ET. In contrast, in a 34% of the study region (9.57 million ha) a clear negative trend in the cover of natural vegetation was observed during 1977–2007 period. The area that had a negative trend in the cover of natural vegetation was 7 times greater than the portion of the region experiencing positive trends. Such number indicates an imbalance in the landscape dynamics that would further reduce areas covered by natural vegetation.
•We evaluated the occurrence of Forest/Ecological Transition in the argentine Semiarid Chaco.•We observed a systematic loss of the surface occupied by natural vegetation.•Only a 4.8% of the study area was compatible with a Forest/Ecological Transition situation.•In contrast, 34% was negative trend in the cover of natural vegetation.•That imbalance isn't compatible with a land-sparing or Forest/Ecological Transition processes.
Despite much deforestation in the past, the northwestern Argentinean province of Salta still has more than 6 million hectares of native forests. Land use conversion for agriculture is threatening ...these forests and the survival of indigenous populations and small-scale farmers. In November 2007, Argentina’s National Congress passed a law to regulate the management and conservation of native forests. This "Forest Law" required provincial governments to implement comprehensive and participatory Land Use Planning Processes (LUPPs). In this article, we describe and analyze, within a political ecology framework, the LUPP carried out in Salta. We focus on the conflicts derived from the different visions of development held by the interest groups involved, and we highlight some contradictions between their discourses and practices. We argue that "development" or "progress," understood as a process of wealth and power accumulation linked to the possession of land and the production of agricultural commodities, was the leading ideology of political and economic elites in Salta during the LUPP. This ideology, and the established institutional power system behind it, was challenged when the National Supreme Court of Justice decided to suspend logging and deforestation activities on land claimed by marginalized ethnic and socioeconomic groups. We assess the implications of this ruling for the conservation of native forests and local livelihoods. As the final outcome of this case is still uncertain, a number of possible scenarios are presented and discussed.
Forest conservation Kuemmerle, Tobias; Altrichter, Mariana; Baldi, Germán ...
Science (American Association for the Advancement of Science),
02/2017, Letnik:
355, Številka:
6324
Journal Article
En un complejo escenario ambiental, productivo y socioeconómico, el 28 de noviembre de 2007 fue sancionada en Argentina la Ley Nacional No 26.331 de “Presupuestos Mínimos de Protección Ambiental de ...los Bosques Nativos" (conocida como "Ley de bosques") con el propósito de proteger los bosques nativos a escala nacional. En este artículo nos proponemos realizar una síntesis crítica de la información disponible acerca de esta ley a diez años de su sanción, con una aproximación que toma en cuenta aspectos ambientales, económicos y sociales. Caracterizamos el desempeño de esta ley en la Región Chaqueña en cuanto a diferentes dimensiones, identificamos sus principales desafíos y describimos una serie de propuestas que desde el sector de Ciencia y Técnica pueden contribuir a su (re)diseño e implementación en el contexto de las actualizaciones de los Ordenamientos Territoriales de Bosques Nativos provinciales. Para ello, integramos información disponible proveniente de distintas fuentes, tales como normativas (nacionales y provinciales), literatura científica, informes de organismos estatales y de ONG y artículos periodísticos. La Ley de Bosques instaló en la opinión pública de nuestro país la problemática vinculada a la pérdida de bosques nativos y se ha posicionado como el principal instrumento de política forestal nacional para su protección. Si bien hubo una reducción en las tasas de deforestación en la región Chaqueña, no existen evidencias certeras de que esta reducción se deba a su aplicación. La Ley de Bosques en la Región Chaqueña presenta una serie de desafíos para mejorar su desempeño en cuanto a su efectividad, equidad y legitimidad social. En este trabajo se presentan diez observaciones que emergen de la revisión realizada. Por otro lado, se esbozan una serie de propuestas de investigación y acción en torno a la ley vinculadas a esas observaciones. *Ex Aequo https://doi.org/10.25260/EA.18.28.2.0.677
•We study the deforestation drivers in the Argentine Chaco for 25 years.•We model the way those factors operated through time and space.•We evaluate the effect of regulations controlling the land ...transformation.•The legal instruments were insufficient to control land clearings.•The relative importance of the anthropic factors increased through time.
Clearance for agriculture or cattle ranching was the dominant land-cover change during the last two decades in the South American Dry Chaco. The Argentinean portion has been particularly affected, presenting greater deforestation rates than the continental and global averages. Little is known on the control factors of the location and the spatial clearance patterns. In this article we studied (a) deforestation dynamics in the Argentinean Dry Chaco and the factors determining land clearing locations for the last 25 years; (b) changes in the relative impact of those factors through time and space; and (c) the effect of regulations aimed to control the location and magnitude of land transformation. We also tested the “expansion of the agricultural frontier” hypothesis for the Argentinean Chaco. To identify the factors that defined agricultural expansion we used binomial logistic models that were fitted to a set of independent variables (bio-physical, infrastructure and political factors) that could eventually influence the distribution of new agricultural areas. Results indicate that the Forest Law devised by the Argentinean federal government to control the clearing process was insufficient to restrict both the area transformed per year and clearance locations. Agriculture is expanding over marginal areas and land clearing dynamics have been increasingly associated to the proximity to already cleared areas, defining a frontier—advancement pattern which gives the idea of a contagion process. According to our results, the relative importance of the anthropic factors associated to the agricultural expansion in the region increased through time.
The impact of land cover change across the planet continues to necessitate accurate methods to detect and monitor evolving processes from satellite imagery. In this context, regional and global land ...cover mapping over time has largely treated time as independent and addressed temporal map consistency as a post-classification endeavor. However, we argue that time can be better modeled as codependent during the model classification stage to produce more consistent land cover estimates over long time periods and gradual change events. To produce temporally-dependent land cover estimates—meaning land cover is predicted over time in connected sequences as opposed to predictions made for a given time period without consideration of past land cover—we use structured learning with conditional random fields (CRFs), coupled with a land cover augmentation method to produce time series training data and bi-weekly Landsat imagery over 20 years (1999–2018) across the Southern Cone region of South America. A CRF accounts for the natural dependencies of land change processes. As a result, it is able to produce land cover estimates over time that better reflect real change and stability by reducing pixel-level annual noise. Using CRF, we produced a twenty-year dataset of land cover over the region, depicting key change processes such as cropland expansion and tree cover loss at the Landsat scale. The augmentation and CRF approach introduced here provides a more temporally consistent land cover product over traditional mapping methods.
•PES schemes are used to conserve natural ecosystems and improve human livelihoods.•Understanding temporal and spatial enrollment patterns in PES is key.•This can improve conservation of threatened ...ecosystems for long time periods.•We present a large-scale PES program that attracts high conversion threat lands.•But enrollment of these lands was shorter than lands with lower conversion threat.•Both temporal and spatial dimensions of PES enrollment are key for informing policy.
Payments for Ecosystem Services (PES) programs are increasingly emphasized to address challenges of conserving forests. However, concerns remain regarding the ability of PES programs to ensure long-term conservation of threatened lands. Evaluation of large-scale PES programs, including the spatial and temporal patterns of enrollment, is scarce, especially for programs that aim to protect forest from severe threats such as expansion of industrial agriculture. Using information on PES enrollment across 252,319 km2 in the Argentine Chaco, we examined both the duration for which lands are enrolled in PES and their suitability for agriculture. Specifically, we examined whether the PES program has resulted in adverse selection not only in space but also in time. We built spatially explicit generalized linear models using information on participants’ length of contract and the potential of their land for agricultural use. We found the PES program enrolled land in areas with high agricultural potential, but enrollment of these lands occurred for shorter time periods than lands with lower levels of threat from deforestation. Consequently, adverse selection occurred over time but not in space. Our work demonstrates the importance of evaluating both temporal and spatial dimensions of adverse selection in PES for informing policy.
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