Integrating Agricultural Landscapes with Biodiversity Conservation in the Mesoamerican Hotspot

Abstract

The major challenge in tropical land management is to meet the ever-growing demand for agricultural products while conserving biodiversity, providing critical ecosystem services, and maintaining rural livelihoods. This challenge is particularly acute in the Mesoamerican biodiversity hotspot, a region of high conservation value for both wild and domesticated species that is undergoing rapid human population growth, ecological degradation, and loss of traditional farming systems (Myers et al. 2000; Harvey et al. 2005a). Approximately 80% of the region's vegetation has been converted to agriculture, threatening biodiversity. More than 300 of the region's endemic species of flora and fauna are threatened, including at least 107 that are critically endangered (CI 2007). With continuing habitat loss (deforestation is 1.2%/year in Central America and Mexico combined; FAO 2005) and fragmentation of remaining forests, pressure on the region's biodiversity will intensify. Habitat destruction and fragmentation are not the only drivers of biodiversity loss in the region, however. Globalization of market forces, agricultural industrialization, migration, public policy, and cultural changes are driving the transformation of diverse, traditional, smallholder agroecosystems into agroindustrial systems dependent on chemical inputs and mechanization (Conway & Rosset 1996; Perfecto et al. 1996; Angelsen & Kaimowitz 2001). Agroindustrial intensification is often accompanied by significant reductions in tree cover, fallow vegetation, habitat diversity, and forest connectivity. These transformations directly threaten species dependent on natural habitat and undermine indigenous management practices that coevolved with this biodiversity for over 10,000 years (Nigh & Levy Tacher 2008). Despite considerable efforts to protect biodiversity in reserves and parks in Mesoamerica, many of these refuges are small, fragmented, isolated, or poorly protected (Miller et al. 2001), and not all ecosystems or species are represented adequately (Powell et al. 2000; Rodrigues et al. 2004). Besides having inadequate dimensions, most protected areas are embedded within an agricultural landscape, and existing buffer zones are inadequate to alleviate effects of fragmentation, contamination by agrochemicals, hunting, and unsustainable or illegal logging (DeFries et al. 2005). The fate of biodiversity within protected areas is therefore inextricably linked to the broader landscape context, including how the surrounding agricultural matrix is designed and managed (Wallace et al. 2005; Vandermeer et al. 2007). Protecting biodiversity while sustaining agricultural productivity, indigenous cultures, and rural livelihoods, requires a new approach to conservation, particularly in regions such as Mesoamerica, where substantial habitat conversion has already occurred. In contrast to the prevailing trend of managing protected areas and productive lands separately, we propose integrated landscape management in which conservation and production units within the agricultural matrix are managed jointly for long-term sustainability. We do not advocate agricultural intensification to spare further forest conversion (e.g., Green et al. 2005) because this approach is unlikely to have the intended outcome, for reasons discussed elsewhere (Vandermeer & Perfecto 2005, 2007; Matson & Vitousek 2006). Instead conservation efforts should be based on the recognition that how agriculture is conducted and how different land uses are distributed spatially and temporally determine the region's biodiversity (Perfecto & Vandermeer 1997; McNeely & Scherr 2003). Lasting conservation will therefore require alliances among conservation biologists, farmers, and land managers to actively plan the future of Mesoamerican landscapes. Here we use an integrated landscape approach to highlight opportunities for achieving long-term conservation in Mesoamerica. We provide an overview of the potential for agricultural landscapes and traditional smallholder farming to conserve biodiversity, propose an urgent action agenda to guide conservation in agricultural landscapes and stem the loss of biodiversity and traditional farming systems, and outline key socioeconomic, legal, and political conditions needed for successful implementation of the action plan. Although our examples and recommendations focus on Mesoamerica, our approach is relevant to other regions where there are similar challenges to conserving biodiversity in human-modified landscapes. An increasing number of studies in Mesoamerica show that certain agricultural landscapes and traditional smallholder practices contribute to biodiversity conservation (e.g., Estrada & Coates-Estrada 2002; Daily et al. 2003; Mayfield & Daily 2005) and at the same time contribute to increased food production and rural income (Pretty et al. 2003). In particular, heterogeneous agricultural landscapes that retain abundant tree cover (as forest fragments, fallo