Assuming no radical transformation in human behavior, we can expect important changes in biodiversity and ecosystem services by 2050. A considerable number of species extinctions will have taken place. Existing large blocks of tropical forest will be much reduced and fragmented, but temperate forests and some tropical forests will be stable or increasing in area, although the latter will be biotically impoverished. Marine ecosystems will be very different from today's, with few large marine predators, and freshwater biodiversity will be severely reduced almost everywhere. These changes will not, in themselves, threaten the survival of humans as a species.
Resource Type: Journal PapersSustainability requires living within the regenerative capacity of the biosphere. In an attempt to measure the extent to which humanity satisfies this requirement, we use existing data to translate human demand on the environment into the area required for the production of food and other goods, together with the absorption of wastes. Our accounts indicate that human demand may well have exceeded the biosphere's regenerative capacity since the 1980s. According to this preliminary and exploratory assessment, humanity's load corresponded to 70% of the capacity of the global biosphere in 1961, and grew to 120% in 1999.
Resource Type: Journal PapersAquilaria spp. are the main source of gaharu, one of the most valuable non-timber products harvested from tropical forests. In order to assess the impact of gaharu harvesting on populations of Aquilaria spp. in Indonesia, the activities of gaharu collectors were assessed by accompanying them on collecting expeditions.
Given current harvesting practices, it is unlikely that gaharu is being sustainably harvested at present. The results suggest that the gaharu trade may have had a substantial impact on the population size of Aquilaria spp. in Indonesia, and their implications are discussed in the context of setting harvest quotas for regulation of trade, as required by CITES.
Resource Type: Journal PapersOur analyses show significant differences between predictions from different models, with predicted changes in range size by 2030 differing in both magnitude and direction (e.g. from 92 loss to 322 gain). We explain differences with reference to two characteristics of the modelling techniques: data input requirements (presence/absence vs. presence-only approaches) and assumptions made by each algorithm when extrapolating beyond the range of data used to build the model. The effects of these factors should be carefully considered when using this modelling approach to predict species ranges. Main conclusions We highlight an important source of uncertainty in assessments of the impacts of climate change on biodiversity and emphasize that model predictions should be interpreted in policy-guiding applications along with a full appreciation of uncertainty.
Resource Type: Journal PapersWe briefly review recent global trends in habitat area in as many broadly-defined natural habitats as possible, and in indices of animal populations characteristic of those habitats. The information available indicates continuing declines in habitat area and species, but those data are extremely sparse.
Resource Type: Journal PapersThe effects of Pleistocene glaciations on the genetic characteristics of the most austral conifer in the world, Pilgerodendron uviferum, were analysed with specific reference to the hypothesis that the species persisted locally in ice-free areas in temperate South America.
Results indicated that Pilgerodendron populations are highly monomorphic, probably reflecting past population bottlenecks and reduced gene flow. Southernmost populations tend to be the least genetically variable and were therefore probably more affected by glacial activity than northern ones. Populations located outside ice limits seem to have been isolated during the glacial period. The presence of centres of genetic diversity, together with the lack of a significant correlation between genetic and geographical distances and the absence of geographical patterns of allelic frequencies at most analysed alleles, may indicate that Pilgerodendron did not advance southward after the last glaciation from a unique northern refugium, but spread from several surviving populations in ice-free areas in Patagonia instead.
Resource Type: Journal PapersThe importance of non-timber forest products (NTFPs) to rural income was examined in a highland community in the Sierra de Manantlán Biosphere Reserve, Jalisco-Colima, Mexico. Rapid Rural Appraisal (RRA) techniques were used to interview 70 of households in the community of El Terrero. Of the nine plant species identified as NTFP sources, the two principal species traded by the community were tila (derived from the flowers and fruits of the tree Ternstroemia lineata), and blackberry (Rubus spp.). Collecting and selling of NTFPs was almost exclusively undertaken by women, with 80 of respondents participating. NTFP sale ranked as the most important source of cash income for 30 of women interviewed, and either second- or third-most important for the remainder. The research examined harvesting impact on populations of T. lineata, an understory tree species characteristic of cloud forest, which this was assessed in the four most-frequented collecting sites. Our results suggested that current harvesting approaches appear to be sustainable, although 95 of the women interviewed reported a decline in resource availability within the last 15 years, apparently resulting from illegal cutting. Suggestions are made with respect to the sustainable development of NTFP resources to help alleviate poverty within the Reserve.
Resource Type: Journal PapersThe number of environmental variables used during modelling could affect the outcome, but we found no correlation between these and our estimates of extinction risk in global samples. Although further investigation is needed, it is unlikely to result in substantially reduced estimates of extinction. Anthropogenic climate change seems set to generate very large numbers of species-level extinctions.
Resource Type: Journal PapersAs the importance of mountain spaces is more widely recogised, it seems necessary to establish a coherent definition of these spaces. The UNEP World Conservation Monitoring Centre (UNEP-WCMC) proposed the first global delineation in 2000. However, certain European countries have used national definitions of mountain spaces since the 1950s. Within the framework of social and economic integration policies at the heart of the European Union, an agreed delineation of European mountain spaces has been established, based on the definition proposed by UNEP-WCMC. The process of adaptation of the global definition to the European context is described, as well as the results for 29 European countries.
Resource Type: Journal PapersAlthough Asian bamboo species constitute a non-timber forest product of major cultural and economic importance, no detailed regional assessment of their distribution patterns has previously been made. To assess the potential of the existing bamboo species distribution data for production of regional mapping tools for planning the conservation of forest-based biodiversity, data on bamboo distribution and forest cover were combined. Over 1000 bamboo species from 60 genera of woody bamboos were incorporated, allowing the mapping of individual species or groups of species and genera, along with potential species richness and biodiversity hotspots. Over 6.3 million km2 of Asian forest potentially contains bamboo, with highest densities indicated from northeastern India through Burma to southern China, and through Sumatra to Borneo. The highest figures for potential species richness (144 spp per square km) were recorded in forests of south China, including Hainan Island. Despite substantial inadequacies and inconsistencies in knowledge of the taxonomy and distribution of bamboo species, this approach may provide a valuable tool for planning in situ conservation of forest biodiversity.
Resource Type: Journal Papers©2013 UNEP All rights reserved