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1.
Proc Natl Acad Sci U S A ; 115(51): 12859-12867, 2018 12 18.
Artigo em Inglês | MEDLINE | ID: mdl-30487220

RESUMO

Current theoretical models of the commons assert that common-pool resources can only be managed sustainably with clearly defined boundaries around both communities and the resources that they use. In these theoretical models, open access inevitably leads to a tragedy of the commons. However, in many open-access systems, use of common-pool resources seems to be sustainable over the long term (i.e., current resource use does not threaten use of common-pool resources for future generations). Here, we outline the conditions that support sustainable resource use in open property regimes. We use the conceptual framework of complex adaptive systems to explain how processes within and couplings between human and natural systems can lead to the emergence of efficient, equitable, and sustainable resource use. We illustrate these dynamics in eight case studies of different social-ecological systems, including mobile pastoralism, marine and freshwater fisheries, swidden agriculture, and desert foraging. Our theoretical framework identifies eight conditions that are critical for the emergence of sustainable use of common-pool resources in open property regimes. In addition, we explain how changes in boundary conditions may push open property regimes to either common property regimes or a tragedy of the commons. Our theoretical model of emergent sustainability helps us to understand the diversity and dynamics of property regimes across a wide range of social-ecological systems and explains the enigma of open access without a tragedy. We recommend that policy interventions in such self-organizing systems should focus on managing the conditions that are critical for the emergence and persistence of sustainability.


Assuntos
Modelos Teóricos , Alocação de Recursos , Agricultura , Conservação dos Recursos Naturais , Ecossistema , Pesqueiros , Humanos , Propriedade
2.
Sci Total Environ ; 698: 134284, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31505346

RESUMO

Since Aichi Target 11 imposes 10% of national protected marine surface by 2020, the least developed countries have particularly shortcomings towards this goal, this article evaluates the progress of seven West African countries. We compared the area reportedly protected sites from two different sources, the world database on protected areas (WDPA) - which is the official tool to monitor the Aichi 11 Achievements - and the West African Marine Protected Area Network, which conducted a comprehensive survey in collaboration with the national institutions in charge of MPAs. Overall, the countries included in this study are unlikely to achieve the Aichi target. Comparing WDPA protected area figures against database created directly from national data showed large discrepancies. According to national data, Mauritania (3.71%) and Guinea-Bissau (2.15%) had the highest protected areas. Senegal had 1.61% of his EEZ under protection, while other countries had <1%. The difference between WDPA and national data was high with Guinea-Bissau already at 10% of EEZ protected areas status according to the WDPA. WDPA overestimated 5935 km2 of MPAs, corresponding to 41% of the actual total area. Possible explanations for the differences include: countries not transmitting information or doing so incorrectly; methodological transformations of data are inducing errors; and multiple MPA statutes leading to double counting of protected areas. This study also shows that for these countries, to achieve Aichi Target 11, large offshore MPAs are the only viable option, and therefore identifies potential sites, that should be considered in addition to conservation of coastal zones. However, their viability may be constrained due to oil activities and lucrative fishing. The increasingly anthropized littoral zone offers less space favourable to MPAs, while 138,723 km2 still need to be covered in these countries to reach 10% of marine protected area.

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