Ravera F., Tarrason D., Espelta J.M. (2014) Land use change trajectories, conservation status and social importance of dry forests in Nicaragua. Environmental Conservation. : 0-0.EnllaçDoi: 10.1017/S0376892914000186
Interdisciplinary studies have proved the interconnectedness of history and ecology relevant to forest conservation proposals and management policies. Engaging local views and concerns in the evaluation and monitoring process can lead to more robust knowledge in the pursuit of effective conservation. This study aimed to assess the degree to which land use change trajectories influence the state of tropical dry forest conservation, as evaluated by scientists and local people. Focusing on northern Nicaragua, the research identified three historical trajectories for types and magnitude of forest disturbance. The assessment process included inventorying sites under different trajectories and integrating ecological and social indicators (namely local perceptions of biodiversity value and concern over species threat). The different land use change trajectories had no influence on the present structure of the dry forest, but strongly affected species diversity, composition and their social importance. The study provided evidence of positive species selection by farmers, which suggested a feedback loop between ecological conditions, social value and awareness of conservation. Copyright © Foundation for Environmental Conservation 2014.
Ravera F., Tarrason D., Siciliano G. (2014) Rural change and multidimensional analysis of farm's vulnerability: A case study in a protected area of semi-arid northern Nicaragua. Environment, Development and Sustainability. 16: 873-901.EnllaçDoi: 10.1007/s10668-014-9531-z
This paper presents an empirical research in a protected area of northern Nicaragua, aimed at: (a) classifying predominant narratives surrounding present and future pathways of the local rural system, drivers of change, features of livelihoods' vulnerability; (b) understanding current functioning of local metabolic patterns of rural systems by developing a typology of farms and (c) comparing types' vulnerability to current drivers of change. To achieve these objectives, we integrated qualitative and quantitative analytical approaches. The different visions of rural spaces, which emerge from the analysis of the narratives, and the five types of farms, characterized by specific land-time budget and energy and monetary flows, suggest two emerging dynamics of local restructuration in protected areas: (1) a dominant land re-concentration process which is generating increasing inequality in access to resources and a progressive marginalization of the self-sufficient economy of landless and subsistence households; (2) an emergence of a paradigm of 'environmentalization' of rural spaces together with a valorization of small and medium-scale diversified economies. Moreover, the vulnerability assessment focuses on multidimensional features of types' sensitivity to crisis, i.e. risk unacceptability, production instability, economic inefficiency, food and exosomatic energy dependency, as well as capacity to buffer and adapt to change, i.e. access to assets, including labour for men and women, social safety nets and degrees of economic diversification. The discussion highlights the occurrence of trade-off between the solutions adopted by farms within different development paths, suggesting the relevance of the proposed framework of analysis at the interface between science and policy. © 2014 Springer Science+Business Media Dordrecht.
Tarrason D., Ojeda G., Ortiz O., Alcaniz J.M. (2014) Can organic amendments be useful in transforming a mediterranean shrubland into a dehesa?. Restoration Ecology. 22: 486-494.EnllaçDoi: 10.1111/rec.12092
Transforming a shrubland into a dehesa system may be useful for recovering certain productive and regulatory functions of ecosystems such as grazing potential, soil erosion control, and also for reducing the risk of wildfire. However, the productivity of the herbaceous cover and tree development in the transformed system may be limited by soil fertility, especially after wildfire events. Previous studies have shown that adequate doses of sewage sludge may improve soil fertility and facilitate plant recovery, but few studies have focused on plant biodiversity assessment. Here, we compare the effects of sewage sludge that has undergone different post-treatments (dewatering, composting, or thermal drying) as a soil amendment used to transform a fire-affected shrubland into a dehesa, on tree growth and pasture composition (vegetation cover, species richness, and diversity). In the short term, sewage sludge causes changes in both pasture cover and tree growth. Although no major differences in vegetation species richness and composition have been detected, fertilization using sewage sludge was shown to modify the functional diversity of the vegetation community. Rapid replacement of shrubs by herbaceous cover and ruderal plants (e.g. Bromus hordeaceus and Leontodon taraxacoides) and of the three grass species sown (Festuca arundinacea, Lolium perenne, and Dactylis glomerata) was observed, whereas N-fixing species (leguminous) tended to be more abundant in nonfertilized soils and soils amended with composted sludge. These results indicate that sewage sludge modifies the functionality of vegetation when applied to soils, and that the response varies according to the treatment that the sludge has undergone. © 2014 Society for Ecological Restoration.
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