Francisco Dallmeier

Seasonal drought limits tree species across the Neotropics

Within the tropics, the species richness of tree communities is strongly and positively associated with precipitation. Previous research has suggested that this macroecological pattern is driven by the negative effect of water-stress on the physiological processes of most tree species. This process implies that the range limits of taxa are defined by their ability to occur under dry conditions, and thus in terms of species distributions it predicts a nested pattern of taxa distribution from wet to dry areas. However, this ‘dry-tolerance’ hypothesis has yet to be adequately tested at large spatial and taxonomic scales. Here, using a dataset of 531 inventory plots of closed canopy forest distributed across the Western Neotropics we investigated how precipitation, evaluated both as mean annual precipitation and as the maximum climatological water deficit, influences the distribution of tropical tree species, genera and families. We find that the distributions of tree taxa are indeed nested along precipitation gradients in the western Neotropics. Taxa tolerant to seasonal drought are disproportionally widespread across the precipitation gradient, with most reaching even the wettest climates sampled; however, most taxa analysed are restricted to wet areas. Our results suggest that the ‘dry tolerance’ hypothesis has broad applicability in the worlds most species-rich forests. In addition, the large number of species restricted to wetter conditions strongly indicates that an increased frequency of drought could severely threaten biodiversity in this region. Overall, this study establishes a baseline for exploring how tropical forest tree composition may change in response to current and future environmental changes in this region.

Training developing-country nationals is the critical ingredient to conserving global biodiversity

rowing awareness of global change has hastened a range of responses by international bodies, governmental agencies, and nongovernmental organizations concerned with biological conservation. A paucity of qualified personnel in many developing countries has frustrated the implementation of foreign technical assistance, particularly in the environmental conservation sphere (Adams and McShane 1992). Many developing-country nationals attend North American universities, but natural science is not the preferred curriculum. Ironically, the greatest challenges to the developing world are environmental and will ultimately require solutions based on biological knowledge of tropical ecosystems (Robinson 1989, 1992). One of the nations oldest scientific

Planning an Adaptive Management Process for Biodiversity Conservation and Resource Development in the Camisea River Basin

The Smithsonian Institutions Monitoring and Assessment of Biodiversity Program joined Shell Prospecting and DevelopmentPeru (SPDP) to protect biodiversity during a natural gas exploration project. Emphasis was on long-term societal andenvironmental benefits in addition to financial gain for thecompany. The systematic, cyclical adaptive management process was used to generate feedback for SPDP managers. Adaptive management enables ongoing improvement of management policies and practices based on lessons learned from operational activities. Previous to this study, very little information about the local biodiversity was available. Over a 2-year period, the team conducted biological assessments of six taxonomic groups at five sites located within 600 km2. A broad range of management options such as location,timing and technology were developed from the beginning of theproject. They were considered in conjunction with emerging lessons from the biodiversity assessments. Critical decisions included location of a gas plant and the cost of helicopter access versus roads to service the full field development. Bothof these decisions were evaluated to ensure that they were economically and environmentally feasible. Project design changes, addressed in the planning stage, were accepted once consensus was achieved. Stakeholders were apprised of the implications of the baseline biodiversity assessments.

Framework for Assessment and Monitoring of Biodiversity

Data and information on status and trends of biodiversity are necessary to implement sound conservation and management of species and habitats. Biodiversity monitoring and assessment programs (BMAP) are major components of natural resources management plans, such as those for protected area management and those that integrate natural resource use with sustainable development practices. The BMAP is an effective way to learn how ecosystem components interact and influence one another and provides a framework to evaluate the status and trends in the condition of habitats and species of interest and the effectiveness of management practices.

Modified Whittaker Plots as an Assessment and Monitoring Tool for Vegetation in a Lowland Tropical Rainforest

Resource exploitation in lowland tropical forests is increasingand causing loss of biodiversity. Effective evaluation and management of the impacts of development on tropical forests requires appropriate assessment and monitoring tools. We proposethe use of 0.1-ha multi-scale, modified Whittaker plots (MWPs) to assess and monitor vegetation in lowland tropical rainforests.We established MWPs at 4 sites to: (1) describe and comparecomposition and structure of the sites using MWPs, (2) compare these results to those of 1-ha permanent vegetation plots (BDPs),and (3) evaluate the ability of MWPs to detect changes in populations (statistical power). We recorded more than 400 species at each site. Species composition among the sites was distinctive, while mean abundance and basal area was similar. Comparisons between MWPs and BDPs show that they record similarspecies composition and abundance and that both perform equallywell at detecting rare species. However, MWPs tend to record morespecies, and power analysis studies show that MWPs were more effective at detecting changes in the mean number of species of trees ≥10 cm in diameter at breast height (dbh) and in herbaceous plants. Ten MWPs were sufficient to detect a change of 11% in the mean number of herb species, and they were able to detect a 14% change in the mean number of species of trees ≥10 cm dbh. The value of MWPs for assessment and monitoringis discussed, along with recommendations for improving the sampling design to increase power.

Using Genetic Profiles of African Forest Elephants to Infer Population Structure, Movements, and Habitat Use in a Conservation and Development Landscape in Gabon

Conservation of wide-ranging species, such as the African forest elephant (Loxodonta cyclotis), depends on fully protected areas and multiple-use areas (MUA) that provide habitat connectivity. In the Gamba Complex of Protected Areas in Gabon, which includes 2 national parks separated by a MUA containing energy and forestry concessions, we studied forest elephants to evaluate the importance of the MUA to wide-ranging species. We extracted DNA from elephant dung samples and used genetic information to identify over 500 individuals in the MUA and the parks. We then examined patterns of nuclear microsatellites and mitochondrial control-region sequences to infer population structure, movement patterns, and habitat use by age and sex. Population structure was weak but significant, and differentiation was more pronounced during the wet season. Within the MUA, males were more strongly associated with open habitats, such as wetlands and savannas, than females during the dry season. Many of the movements detected within and between seasons involved the wetlands and bordering lagoons. Our results suggest that the MUA provides year-round habitat for some elephants and additional habitat for others whose primary range is in the parks. With the continuing loss of roadless wilderness areas in Central Africa, well-managed MUAs will likely be important to the conservation of wide-ranging species.

Biodiversity and conservation genetics research in Central Africa: new approaches and avenues for international collaboration

A five-day international workshop was recently convened at the Université des Sciences et Techniques de Masuku in Gabon to enhance international collaboration among Central African, US and European scientists, conservation professionals and policy makers. The overall aims of the workshop were to: (1) discuss emerging priorities in biodiversity and conservation genetics research across Central Africa, and (2) create new networking opportunities among workshop participants. Here we provide a brief overview of the meeting, outline the major recommendations that emerged from it, and provide information on new networking opportunities through the meeting web site.

A review of the impact of pipelines and power lines on biodiversity and strategies for mitigation

Linear infrastructure such as pipelines and power lines is ubiquitous and responsible for loss of habitats and disruption of landscape connectivity. We reviewed published research to answer the following questions: (1) Which organisms are commonly used to indicate impacts of pipelines and power lines to biodiversity? (2) How do pipelines and power lines impact biodiversity? and (3) How are these impacts mitigated? Studies of pipelines most often used mammals and plants as bioindicators, whereas studies of power lines focused largely on birds and plants. A myriad of impacts were identified, including the mortality of plants during construction, changes to the structure and composition of plant and animal communities that resulted from construction, the creation of open and shrubby corridors within intact forests, and collisions and electrocutions of birds with power lines. However, in most studies baseline data were not collected, so magnitudes of the impacts are often unknown. Mitigation in many studies was mentioned only in the discussion as a way to reduce impacts, but mitigation techniques were rarely tested directly. We outline considerations when selecting bioindicators—research that takes a community- or ecosystem-level approach will more fully determine the scope of impacts of linear infrastructure than the historical approach of focusing on populations of select bioindicators. Mitigation strategies must ultimately result from appropriate baseline studies, scientific data collection and analyses, and be implemented within an adaptive management strategy.

Measuring and Monitoring Forest Biodiversity: The SI/MAB Model

Over the past decade, the Smithsonian Institution/Man and the Biosphere Biological Diversity Program (SI/MAB) has developed a biodiversity monitoring protocol and refined it through testing at a number of sites. The protocol has been adopted by SI/MAB colleagues and partners around the world, forming the basis for consistent measuring and monitoring at hundreds of biodiversity monitoring plots, facilitating the transfer of comparable data, and providing the framework for data analysis and dissemination to users. Program staff have trained more than 700 participants in the SI/MAB protocol and in use of BioMon (SI/MAB’s computerized data management system) at annual six-week international courses and through on-site two-week courses in more than two dozen countries. Staff have also been instrumental in setting up and maintaining international biodiversity information exchange networks. The primary goals of the program — to gather, analyse, and disseminate information about biodiversity at selected forested sites throughout the world and to foster co-operation among researchers and decision-makers — are being met. The outlook for strengthening established networks and expanding the program into new areas is bright.

Identifying and Avoiding Sensitive Habitats in Petroleum Operations

Defining and understanding the habitats in which a company is operating is a key step toward the reduction of impacts on biodiversity. Identification of vegetation types is a commonly-used method for mapping an area of operations, and these vegetation types are often used as a surrogate for plant and animal habitats, but defining these types too finely may result in limited biological importance of these types for plants and animals, and may complicate the conservation planning process. Instead, habitat maps based on more coarse-scale but biologically important data such as elevation and geologic history can result in more useful maps of plant and animal communities and can lead to better land management during operations. We created habitat maps for Blocks 39 and 57 in northeastern and south central Peru, respectively, using Landsat imagery and elevation data. In Block 39, three different geological formations, or habitat types, were identified in the map, while four were identified in Block 57. In order to confirm that the habitats identified in this study are biologically distinct in terms of plant and animal communities, CCES researchers assessed soil samples and a variety of taxonomic groups including ferns, birds, bats, amphibians and reptiles in each. The protocol requires a minimum of five days sampling for each taxonomic group in a minimum of four different areas within each distinct habitat in order to ensure thorough data collection. We then use this data to test and redefine the boundaries of habitats, and to identify habitats with communities of plants and animals of special conservation concern. In the cases of Blocks 39 and 57, recommendations were made to the company regarding where to avoid or limit operations, in order to reduce negative impacts on special habitats and improve the likelihood and cost-effectiveness of habitat restoration post-operations.