Grid-based monitoring methods for detecting population declines: Sensitivity to spatial scale and consequences of scale correction

A decrease in the area of occupancy of a species is often criterion by which a species is classified as threatened (i.e. IUCN Red List). However, it is unclear how to accurately measure change in area of occupancy. Area of occupancy is a measure of distribution and the spatial scale at which the distribution is measured will affect the ability to detect a decline. To overcome errors introduced by measuring distribution at different spatial scales, scale correction methods are often applied. It is known that scale correction reliably estimates area of occupancy; however, its suitability to estimate trends in area of occupancy has not been assessed. We investigate the effect of spatial scale and implementation of scale correction when estimating two different forms of decline in area of occupancy: spatially correlated and spatially uncorrelated declines. We explore these issues using simulations of three declining species and a grid-based monitoring method designed to detect the declines. Our results suggest that current grid-based methods are inadequate for detecting uncorrelated local extinctions, even if the total decline is substantial (e.g. 65% of the original range). We demonstrate that scale correction will lead to misleading conclusions in some situations. We suggest an alternative survey method to accurately estimate changes in area of occupancy over time. We provide guidelines for designing grid surveys to measure changes in area of occupancy to assess a species threat status using the IUCN Red List criterion.     

Simulating the effects of using different types of species distribution data in reserve selection

In a perfect world, systematic conservation planning would use complete information on the distribution of biodiversity. However, information on most species is grossly incomplete. Two main types of distribution data are frequently used in conservation planning: observed and predicted distribution data. A fundamental question that planners face is - which kind of data is better under what circumstances? We used simulation procedures to analyse the effects of using different types of distribution data on the performance of reserve selection algorithms in scenarios using different reserve selection problems, amounts of species distribution known, conservation targets and costs. To compare these scenarios we used occurrence data from 25 amphibian and 41 reptile species of the Iberian Peninsula and assumed the available data represented the whole truth. We then sampled fractions of these data and either used them as they were, or converted them to modelled predicted distributions. This enabled us to build three other types of species distribution data sets commonly used in conservation planning: “predicted”, “transformed predicted” and “mixed”. Our results suggest that reserve selection performance is sensitive to the type of species distribution data used and that the most cost-efficient decision depends most on the reserve selection problem and on how much we have of the species distribution data. Choosing the most appropriate type of distribution data should start by evaluating the scenario circumstances. While there is no one best approach for every scenario, we discovered that using a mixed approach usually provides an acceptable compromise between species representation and cost.     

Rules of benefit distribution: A dynamic impact on Nepalese community forestry organizations

Participatory approach has been an official part of Community Forestry (CF) since 1989 when Master Plan for the Forestry Sector (1989) was introduced in Nepal. However, many problems related to benefit distribution from CF have emerged because of the way decision-making is influenced by social and institutional structures present at community level, particularly in terms of dominance by wealthy and caste elite to formulate rules. The study used a conceptual approach using elite theory with models that looked at Executive Committee (EC) that used to formulate distribution rules. The study uses Community Forestry User Groups (CFUGs) level data from 31 CFUGs and household data from 310 households in Baglung district, Nepal. The study examined the factors linked with rules of distribution that determined the relative distribution of forest products. The higher the representation of the poor and disadvantaged households on the EC, the greater the benefits to them in terms of greater quantities distributed and longer collection periods. The policy implication of this study is that the forestry organizations help the poor and underprivileged households to build up capacity to undertake leadership roles that influence the formulation of rules through which organizational elite models in favor to them become part of the elite decision-making.     

Conserving seeds of useful wild plants in Mexico: main issues and recommendations

The efficient storage and germination of seeds underpin the effective use of plants for livelihoods and sustainable development. A total of 204 wild species useful for local communities of the Tehuacán–Cuicatlán Valley were collected and stored in seed banks in country for long term conservation, and 66 % (i.e., 134) duplicated in the U.K., as an effective means of ex situ conservation. Of the 204 species, 147 (122 of which also duplicated in the U.K.) were previously listed as useful plants in the ethnofloristic inventory of the Valley. Based on literature surveys, we found that one of the major impediments to the use of stored seeds of wild species is the lack of knowledge of how to germinate the seed. In detailed studies, we found that seeds of 18 useful plant species from 10 different families germinated readily and could be propagated. In contrast, four species (Actinocheita filicina, Bursera submoniliformis, Karwinskia mollis and Lippia graveolens) produced dormant seeds and therefore further studies are needed before their use can be maximised in large scale propagation programmes in support of conservation and livelihoods. Overall, this large-scale study on useful wild plant species in Mexico confirms that conventional seed banking can effectively support sustainable development and livelihood programmes.