Identifying and mapping biodiversity processes for conservation planning in islands: A case study in Réunion Island (Western Indian Ocean)

Over the last century, island biodiversity has become one of the most threatened in the world. Although many island conservation plans address biodiversity requirements at the species level, few plans address the spatial requirements of the biodiversity processes that underpin the persistence of these species. Using systematic conservation planning principles, we map the spatial components of biodiversity processes (SCBPs) and use these to design broad-scale conservation corridors for Réunion Island. Our method is based upon a literature review, expert knowledge, spatially explicit base data, conservation planning software, and spatial modelling. We combine a target-driven algorithm with least-cost path analyses to delineate optimal corridors for capturing key biodiversity processes while simultaneously considering biodiversity pattern targets, conservation opportunities, and future threats. We identify five SCBPs: the oceanic-terrestrial interface; riverine corridors; macrohabitat interfaces; the boundaries of isolated topographic units; and lowland-upland gradients. A large proportion of the SCBPs (81.3%) is currently untransformed, whereas 3% is irreversibly transformed by urbanisation and 15.7% is transformed but restorable. However, SCBPs are almost fully disrupted by urbanisation in the lowlands, thereby compromising functional corridors along full altitudinal gradients. This study is a contribution toward the reconciliation of conservation versus development objectives on Réunion Island but we believe that the delineation method is sufficiently general to be applied to other islands. Our results highlight the need for integrating marine, coastal and terrestrial conservation planning as a matter of urgency, given the rapid transformation of coastal areas on islands.     

CITES, sustainable use of wild species and incentive-driven conservation in developing countries, with an emphasis on southern Africa

Over 30,000 species of animals and plants that are, or may be, detrimentally affected by international trade are listed on the Appendices of the Convention on International Trade in Endangered Species of Wild Flora and Fauna (CITES). The Convention aims to regulate transboundary trade in species and their derivatives through a system of permits and certificates, and to ensure that such trade conforms to the principle of sustainability. In the developing world, a considerable component of its biodiversity lives outside protected areas where governments have limited potential to manage wildlife. Based on selected vertebrate and plant species, this paper concludes that: (1) use of wildlife in developing countries is more likely to be an imperative rather than a choice; (2) the legal instruments of CITES have limited capacities to ensure that international trade is sustainable; (3) sustainable use of species is best achieved by gaining the support of affected local communities; (4) community support can be maximized by the devolution of ownership or user rights of species from the state to, e.g., the communal level, and the development of effective economic incentive structures to prevent alternative land-use strategies; (5) countries in southern Africa have pioneered devolution of ownership/user rights to the district/communal level; (6) in combination with effective CITES trade controls, trade opportunities, rather than trade restrictions, are most likely to assist in the development of incentive-driven conservation strategies; (7) to avoid negative incentives and to increase awareness of livelihoods, the international CITES community may need to consider whether CITES Appendices I and II listing decisions should be based not only on biological/trade criteria but also on socio-economic considerations, if it is in the conservation interest of the species concerned; (8) a strategic cooperation with the Convention for Biological Diversity (CBD) could improve strategies for sustainable trade; (9) while incentive-driven conservation can provide significant longer-term potential for the protection of animal and plant species, it may be most difficult to achieve for species whose high-value products have a long tradition in medicinal use and (10) the conditions under which incentive-driven conservation is most likely to promote sustainable use need to be clearly identified.     

Relative effects of fragment size and connectivity on bird community in the Atlantic Rain Forest: Implications for conservation

It is known that large fragment sizes and high connectivity levels are key components for maintaining species in fragments; however, their relative effects are poorly understood, especially in tropical areas. In order to test these effects, we built models for explaining understory birds occurrence in a fragmented Atlantic Rain Forest landscape with intermediate habitat cover (3%). Data from over 9000 mist-net hours from 17 fragments differing in size (2-175 ha) and connectivity (considering corridor linkages and distance to nearby fragments) were ranked under a model selection approach. A total 1293 individuals of 62 species were recorded. Species richness, abundance and compositional variation were mainly affected by connectivity indices that consider the capacity of species to use corridors and/or to cross short distances up to 30 m through the matrix. Bird functional groups were differently affected by area and connectivity: while terrestrial insectivores, omnivores and frugivores were affected by both area and connectivity, the other groups (understory insectivores, nectarivores, and others) were affected only by connectivity. In the studied landscape, well connected fragments can sustain an elevated number of species and individuals. Connectivity gives the opportunity for individuals to use multiple fragments, reducing the influence of fragment size. While preserving large fragments is a conservation target worldwide and should continue to be, our results indicated that connectivity between fragments can enhance the area functionally connected and is beneficial to all functional groups and therefore should be a conservation priority.     

The influence of fruit abundance on the use of forest and cultivated field habitats by the endemic Madeira laurel pigeon Columba trocaz: Implications for conservation

This study was conducted over a two year period in the north west of Madeira Island (Macaronesian Atlantic Islands, Portugal). It investigates the relationship between fruiting patterns in the indigenous forest and the use by the Madeira laurel pigeon of forest habitats and cultivated areas. Habitat use observations were carried out using line-transects in forest sites where the availability of fruit (the most important element of the diet) was assessed. The use of agricultural fields was measured indirectly by the assessment of the damage caused to crops. The findings provided strong evidence that bird movements and shifts in abundance are related to fruit usage and availability. The use of fruits is mostly opportunistic but when many species are available, selection was observed. From an ecological perspective, our findings indirectly confirm a high concordance between pigeon diet, studied by microhistological techniques, and habitat use. The use of crops also seems to be mostly opportunistic and is governed by the birds’ movements within the adjacent forest. It is hypothesised that fruit phenology will influence the use of agricultural areas only to the extent that it governs such movements; there is no strong evidence that crops are attacked only when the availability of natural foods is low. Our results suggest that the current management strategy for the forest is adequate for the conservation of this pigeon but that the conservation value of forest edges should be redefined. It is also proposed that crop damage may be reduced by identifying the proximate factors, which lead to the use of specific fields.     

Microsatellite diversity and effective population size in a germplasm bank of <Emphasis Type="Italic">Hymenaea courbaril</Emphasis> var. <Emphasis Type="Italic">stilbocarpa</Emphasis> (Leguminosae), an endangered tropical tree: recommendations for conservation

Deforestation in southeast Brazil has led to the extinction of Hymenaea courbaril var. stilbocarpa and ex situ conservation has been established. In this study, the levels of genetic diversity and the effective population size of H. courbaril in a germplasm bank were investigated using six nuclear microsatellite loci. A total of 79 and 91 alleles were found in 65 seed-trees and their 176 offspring, respectively. Offspring have a higher average number of alleles per locus (A = 15.2) than seed-trees (A = 13.2), but lower observed heterozygosity (offspring: H _o = 0.566; seed-trees: H _o = 0.607). The estimate of outcrossing rate shows that the study population is perfectly outcrossed (t _m  = 0.978, P > 0.05). Significant deviations from random mating were detected through mating among relatives and correlated matings. The average variance in effective population size for each family was 2.63, with a total effective population size retained in the bank of 170.1. These results confirm that the preserved population of H. courbaril retains substantial genetic variability. Moacyr Antonio Mestriner and Ana Lilia Alzate-Marin—CEEFLORUSP Members.