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361.
ABSTRACT

Forest frontiers worldwide reveal trade-offs that are key in mitigating global change. In the forest frontiers of northeast Madagascar, land-use changes result from decisions made by smallholder farmers. In the past, subsistence needs led to increasing shifting cultivation, resulting in forest degradation and deforestation. This study focuses on investigating the role of locally determined factors in land-use change decisions in the forest frontier context. Therefore, we developed a Bayesian network-based land-use decision model that represents the causalities between factors influencing land-use decisions and takes into account local decision-makers’ knowledge. The approach is applied in two comparative case studies in northeast Madagascar. Results show that farmers mostly aim at extending the cultivation of cash crops. These results and the causal mechanisms disentangled for the forest frontier of northeast Madagascar help understand change mechanisms and hence, support decision-making to attain the Sustainable Development Goals.  相似文献   
362.
This paper is a summary and elaboration of an earlier publication in Dutch on the compilation of a landscape-ecological map, scale 1 : 50 000, of the Dutch coast. It is argued that such an integrated map is the best basis for the conservation and management of the coastal dunes and salt marshes. It may be combined with local more detailed vegetation maps, some examples of which are mentioned in the context of management. The Dutch North Sea coast is a ca. 350 km long chain of sandy beaches and sand dunes, from only 100 m to more than 10 km wide. On sheltered stretches of dune coasts along estuaries in the Southwest and on the Wadden Sea islands, salt marshes have developed. The small-scale gradient structure of the beach-dune-salt marsh complex is emphasized.  相似文献   
363.
Changes in agricultural land use are responsible for significant modifications in mountain landscapes. This study is part of an interdisciplinary research on the processes and consequences of spontaneous afforestation of Pyrenean landscapes by ash, and the possibilities for its management. We address the relationships between vegetation dynamics and land-use change from the combination of an agricultural study of change in farm management and an ecological study of grassland colonization by ash. In the framework of a village case study, we characterized parcels management and land-use histories, and analyzed the dynamics of the composition of grassland vegetation communities. From a joint analysis of the results obtained in each discipline, we discuss the limitations and complementarities of the two approaches for the interdisciplinary assessment of the afforestation process.  相似文献   
364.
中国泰和鸡种质资源开发史   总被引:1,自引:0,他引:1  
泰和鸡是我国著名的观赏及药用鸡种,是著名中成药“乌鸡白凤丸”的主要配方用料之一。本文根据实地考察和大量历史资料的分析研究,论述了泰和鸡品种的开发历史及其选育过程。指出泰和鸡在我国已有1300多年的饲养及药用历史。在距今400多年前,泰和鸡始由雏型到品种的初步形成,由血缘紊乱,遗传性状极不稳定至遗传性伏的相对统一,大体约经过了240年的自然选择与人工选择,而品种特征的相对固定,又经过了200多年的选育过程。这是我国劳动人民辛勤培育的结果。本文为进一步合理利用泰和鸡种质资源和发挥我国特有种质资源的生产潜力特提供一些科学依据,这对泰和鸡的深入研究将具有一定的参考价值。  相似文献   
365.
The rise of the postwar environmental movement is rooted in the development of ecological consciousness within intellectual circles as well as the general public. Though many commentators cite the 1960s as the focal point of the new environmentalism, the ecological ethic had actually evolved by the 1930s in the writings and speeches of both scientists and public commentators. Agricultural conservationists led the way in broadcasting the message of ecology. Friends of the Land, an agriculturally-oriented conservation organization formed in 1940 and active through the 1950s, is an interesting example of how the agricultural community was an integral component in the rise of environmentalism. While Friends of the Land flourished only for a brief period, its goals and the ideas that the group represented illustrate how the ecological ethic was burgeoning by the early-1950s. Furthermore, the history of Friends of the Land is an important chapter in the ongoing quest for ecological agriculture and societal permanence.  相似文献   
366.
200 years of sustainability in forestry: Lessons from history   总被引:4,自引:0,他引:4  
Since the end of the 1980s the concept of sustainable development has gained general acceptance, but much uncertainty still exists on how to operationalize this concept. In forestry the concept of sustainability has been an accepted principle since the 18th century. The experiences with its application in forestry may contribute towards obtaining a better insight into the implications and operational significance of the concept of sustainability. This article describes the history of sustainability in forestry, including the various social values on which its interpretation has been based. The original principle of sustained yield has gradually been broadened to a more inclusive principle of sustainable forest management. The dynamics in social valuation of forest resources resulted in various attempts at practical operationalization of the principle. Notwithstanding 200 years of efforts to operationalize the concept of sustainability, its exact application in forestry remains troublesome. Three lessons are drawn: (1) the need to recognize the different nature of ecological limits and social dynamics, (2) the role of dynamic social values with respect to forest resources, and (3) the significance of operational experiences in trying to attain sustainability within a concrete context.  相似文献   
367.
论我国灾害历史的研究   总被引:4,自引:0,他引:4  
许厚德 《灾害学》1995,10(1):18-21
灾害史的研究是灾害学研究的一个重要领域,本文在列举我国历史灾害资料的基础上,论述了灾害历史研究的必要性。  相似文献   
368.
The natural histories of crop-related wild species in their native habitats can be used to develop novel pest management strategies. Traditionally, such information has provided insights for biological control, plant breeding, crop management, and applied ecology Further insights can be garnered.  相似文献   
369.
370.
This perspective recognizes the seminal Ambio articles of Sombroek et al. (1993), Turner et al. (1994) and Brussaard et al. (1997), identifying their individual and collective role in laying the ground work for a global change research agenda on land and its human use through increased understanding of terrestrial ecosystem dynamics and global change, and furthering nascent interdisciplinary efforts within the global change science community to better understand the ‘human driving forces’ of change. From these efforts, land system science, as a systemic science focused on complex socio-ecological interactions around land use and associated trade-offs and synergies, emerges as an ‘interdiscipline’ challenged to better understand land systems as the ‘meeting ground’ for multiple claims on land for biodiversity, carbon, livelihoods, food production among others, and support pathways to sustainability for people and nature.  相似文献   
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