Benefit-cost analysis of fuelwood management using native alder in Ecuador

The profitability of four farm-level fuelwood management alternatives were examined using benefit-cost analysis. The value of alder wood is based on the market price of a cubic meter of fuelwood sold in Saraguro, Loja, Ecuador. A sensitivity analysis of wage rate, fuelwood price, and project subsidies tests the effects of changes in key economic parameters on project profitability. Present trends in fuelwood demand and social externalities are examined and the subsidy bill is estimated for implementing an alder management plan.School of Renewable Natural Resources, University of Arizona     

Removal of nonnative fish results in population expansion of a declining amphibian (mountain yellow-legged frog, Rana muscosa)

The mountain yellow-legged frog (Rana muscosa) was once a common inhabitant of the Sierra Nevada (California, USA), but has declined precipitously during the past century due in part to the introduction of nonnative fish into naturally fishless habitats. The objectives of the current study were to describe (1) the effect of fish removal from three lakes (located in two watersheds) on the small, remnant R. muscosa populations inhabiting those lakes, and (2) the initial development of metapopulation structure in each watershed as R. muscosa from expanding populations in fish-removal lakes dispersed to adjacent habitats. At all three fish-removal lakes, R. muscosa population densities increased significantly following the removal of predatory fish. The magnitude of these increases was significantly greater than that observed over the same time period in R. muscosa populations inhabiting control lakes that remained in their natural fishless condition. Following these population increases, R. muscosa dispersed to adjacent suitable (but unoccupied) sites, moving between 200 and 900 m along streams or across dry land. Together, these results suggest that large-scale removal of introduced fish could result in at least partial reversal of the decline of R. muscosa. Continued monitoring of R. muscosa at the fish-removal sites will be necessary to determine whether the positive effects of fish eradication are sustained over the long-term, especially in light of the increasingly important role played by an emerging infectious disease (chytridiomycosis, caused by Batrachochytrium dendrobatidis) in influencing R. muscosa populations.     

塞拉里昂海域双支架虾拖网作业中试验小网设计的研究

本文应用动力相似原理,研究设计了塞拉里昂渔场双支架虾拖网的试验小网,用来判断渔场资源和中心渔场。通过对试验小网的研究设计和实际应用发现,使用试验小网判断渔场的资源情况,具有快速性、方便灵活性和实用性等特点。     

Integrating wild mushrooms use into a model of sustainable management for indigenous community forests

Recently, the importance of fungal resources has been brought to the forefront due to their ecological and economical importance. There have been many efforts to record their diversity at local and regional scales. However, few studies deal with the potential value of fungi for the development of local communities, particularly in developing countries. The present study presents the results of a five-year inventory of useful mushrooms in the communal land of Ixtlan de Juarez, Oaxaca. We use the species list to analyze the real possibility of local communities incorporating these resources into a model of local development exploiting wood and non-wood forest products in the context of Smart wood certification. The model discusses three main strategies for mushroom management (diversification of forest exploitation, incorporation of soil function to forestry and fungal technology development); in each case we also discuss the viability and infrastructure necessary to implement it. We identified a total of 159 taxa of useful mushrooms and provide information on their habit, substrate, abundance and recorded use. Thirteen taxa were Ascomycetes and 146 Basidiomycetes; belonging to 42 families and 73 genera. A total of 38 taxa (23.9%) were new records for the state of Oaxaca. This is, to date, the most comprehensive list of useful mushrooms presented in Mexico. It demonstrates the huge mycological diversity of these resources present in the Juarez’ Mountain Range. A total of 113 species are edible, 38 species have direct applications in forest management, 19 species have medicinal properties, 12 are toxic and 12 species have recorded biotechnological applications. The diversity and heterogeneity of potential uses of these resources represent a challenging opportunity for local communities. Product diversification is a fundamental strategy to integrate a model of sustainable forest exploitation. We concluded that communities developing forestry activities must be aware of the functional properties of ectomycorrhizal and saprotrophic fungi to include them in their own forest management plans. We also outline a set of common steps for initiating sustainable and diversified forestry practices which include: awareness-raising targeted to local authorities and forestry technicians on the ecological importance of mushrooms; illustrated catalogues on useful species accessible to all the communities, which would allow taxonomic identification for all species; local technical capacity to obtain and disseminate strains of mycorrhizal and saprotrophic fungi; obtaining resources to develop infrastructure to cultivate mushrooms, among many others projects.     

Forest Utilization in the Sierra Juarez,Oaxaca, Mexico

Abstract

As one of the most diverse biological regions in the seasonal tropics, Oaxaca's main management challenge is balancing sustainable forest harvesting with preserving biological diversity, especially challenging for a village community with limited resources—both economic and technical. A closer look at the history of forest management activities in Sierra Juarez shows exploitative practices by Fabricas de Papel Tuxtapec (FAPATUX), a national paper manufacturer. In 1956, FAPATUX acquired a 25 year concession to harvest the communal forests of Ixtlán. Despite the success of the communities in working with FAPATUX and influencing the management of the communal lands, the communities eventually demanded greater control over the lands and sought to prevent the continuation of the concessions. Since then, communal forest management has sought to achieve two primary goals: (1) to provide economic returns and employment, and (2) to steward the land responsibly and sustainably. Their management plan has evolved into the manipulation of standard silvicultural procedures and their integration with traditional agricultural practices. The management of the timber resources in Ixtlán will continue to be a dynamic process. Having the flexibility to respond to failures and ever-changing conditions will ensure that Ixtlán will adapt its management and silvicultural systems over time to achieve its objectives.