RESUMO
Agricultural landscape homogenization has detrimental effects on biodiversity and key ecosystem services. Increasing agricultural landscape heterogeneity by increasing seminatural cover can help to mitigate biodiversity loss. However, the amount of seminatural cover is generally low and difficult to increase in many intensively managed agricultural landscapes. We hypothesized that increasing the heterogeneity of the crop mosaic itself (hereafter "crop heterogeneity") can also have positive effects on biodiversity. In 8 contrasting regions of Europe and North America, we selected 435 landscapes along independent gradients of crop diversity and mean field size. Within each landscape, we selected 3 sampling sites in 1, 2, or 3 crop types. We sampled 7 taxa (plants, bees, butterflies, hoverflies, carabids, spiders, and birds) and calculated a synthetic index of multitrophic diversity at the landscape level. Increasing crop heterogeneity was more beneficial for multitrophic diversity than increasing seminatural cover. For instance, the effect of decreasing mean field size from 5 to 2.8 ha was as strong as the effect of increasing seminatural cover from 0.5 to 11%. Decreasing mean field size benefited multitrophic diversity even in the absence of seminatural vegetation between fields. Increasing the number of crop types sampled had a positive effect on landscape-level multitrophic diversity. However, the effect of increasing crop diversity in the landscape surrounding fields sampled depended on the amount of seminatural cover. Our study provides large-scale, multitrophic, cross-regional evidence that increasing crop heterogeneity can be an effective way to increase biodiversity in agricultural landscapes without taking land out of agricultural production.
Assuntos
Agricultura , Biodiversidade , Produtos Agrícolas , Ecossistema , Animais , Abelhas , Aves , Borboletas , Europa (Continente) , Humanos , América do Norte , AranhasRESUMO
The concept of ecological solidarity (ES) is a major feature of the 2006 law reforming national park policy in France. In the context of biodiversity conservation, the objectives of this study are to outline the historical development of ES, provide a working definition, and present a method for its implementation that combines environmental pragmatism and adaptive management. First, we highlight how ES provides a focus on the interdependencies among humans and nonhuman components of the socioecological system. In doing so, we identify ES within a framework that distinguishes ecological, socioecological, and sociopolitical interdependencies. In making such interdependencies apparent to humans who are not aware of their existence, the concept of ES promotes collective action as an alternative or complementary approach to state- or market-based approaches. By focusing on the awareness, feelings, and acknowledgement of interdependencies between actors and between humans and nonhumans, we present and discuss a learning-based approach (participatory modeling) that allows stakeholders to work together to construct cultural landscapes for present and future generations. Using two case studies, we show how an ES analysis goes beyond the ecosystem management approach to take into account how human interactions with the environment embody cultural, social, and economic values and endorse an ethically integrated science of care and responsibility. ES recognizes the diversity of these values as a practical foundation for socially engaged and accountable actions. Finally, we discuss how ES enhances academic support for a socioecological systems approach to biodiversity conservation and promotes collaboration with decision-makers and stakeholders involved in the adaptive management of protected areas and their surrounding landscapes.
Assuntos
Conservação dos Recursos Naturais , Ecossistema , Meio Social , Meio Ambiente , França , Humanos , PolíticasRESUMO
Protected areas (PAs) remain central to the conservation of biodiversity. Classical PAs were conceived as areas that would be set aside to maintain a natural state with minimal human influence. However, global environmental change and growing cross-scale anthropogenic influences mean that PAs can no longer be thought of as ecological islands that function independently of the broader social-ecological system in which they are located. For PAs to be resilient (and to contribute to broader social-ecological resilience), they must be able to adapt to changing social and ecological conditions over time in a way that supports the long-term persistence of populations, communities, and ecosystems of conservation concern. We extend Ostrom's social-ecological systems framework to consider the long-term persistence of PAs, as a form of land use embedded in social-ecological systems, with important cross-scale feedbacks. Most notably, we highlight the cross-scale influences and feedbacks on PAs that exist from the local to the global scale, contextualizing PAs within multi-scale social-ecological functional landscapes. Such functional landscapes are integral to understand and manage individual PAs for long-term sustainability. We illustrate our conceptual contribution with three case studies that highlight cross-scale feedbacks and social-ecological interactions in the functioning of PAs and in relation to regional resilience. Our analysis suggests that while ecological, economic, and social processes are often directly relevant to PAs at finer scales, at broader scales, the dominant processes that shape and alter PA resilience are primarily social and economic.
Assuntos
Conservação dos Recursos Naturais/métodos , Ecossistema , Animais , Atitude , Humanos , Modelos Teóricos , Opinião Pública , Rede Social , Valores Sociais , África do SulRESUMO
Policy for biodiversity conservation must evolve to cope with the increasing human footprint on natural systems. A major issue here is the need for policy for protected areas, which integrates their surrounding landscape and local human populations in the construction of socially grounded measures. To illustrate current conceptual thinking in this direction we present and provide a conceptual basis for a recent initiative in national park policy in France that is based on "ecological solidarity". In the light of other policy ideas and tools that have recently emerged for the co-construction of conservation policy, we argue that this concept provides an imaginative step towards consolidating ecological and social interdependence in biodiversity policy that goes beyond statutory park boundaries.