The 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 Papers
Global and regional coral reef area statistics are of considerable value in fields ranging from global environmental change to fisheries to conservation. Although widely quoted, Smith's 1978 figure of 600 000rkm2 is only an approximate calculation. The World Conservation Monitoring Centre has prepared a new estimate of reef coverage by mapping emergent reef crest and very shallow reef systems. These data were rasterised, using 1rkm grid squares, as a means of reducing errors arising from variation in scale. Global and regional reef coverages were calculated from the resultant grid. The total global area is estimated at 255 000rkm2, considerably lower than many previous estimates. Variation in reef area estimates is, in part, a function of variation in reef definition.Resource Type: Journal Papers
Governments are often accused of responding only to short-term and parochial considerations. It is therefore remarkable that representatives of 190 countries recently committed themselves at the Convention on Biological Diversity to reducing biodiversity loss. This presents conservation biologists with perhaps their greatest challenge of the decade. The authors of this Policy Forum describe approaches to identifying more of the earth's biological diversity; understanding how biological, geophysical, and geochemical processes interact; and presenting scientific knowledge in time to contribute to and achieve the 2010 target.Resource Type: Journal Papers
The forests of eastern Tanzania are a globally important biodiversity hotspot. In this study 361 eastern Tanzanian restricted range forest tree taxa were assessed. Of these taxa, 223 occurred in the Eastern Arc, 150 in Coastal forests, 17 in Northern forests and 21 in the Lake Nyasa forests. The majority of the taxa had restricted elevational ranges with 76.3 occurring in no more than two 200 m elevational bands out of a total potential elevation range of 3000 m. The majority of the taxa occupied a small area in the eastern Tanzanian forests, with 201 taxa being only found at a few sites. In determining priority areas for conservation, selection of taxon definitions can have important effects. For example, tree size varies with elevation, so if only large trees are used then site selection will be biased towards particular areas.Resource Type: Journal Papers
This study demonstrates the utility of carbon isotope discrimination in describing genetic adaptation to arid environments, although it is probably most useful in detecting differentiation when the strategy of the species under investigation is to increase water use efficiency, rather than drought-avoidance. The results suggest that populations on the eastern and western sides of the Andes should be treated as separate management units for the purposes of conserving the genetic resource of this species.Resource Type: Journal Papers
In order to build on the momentum created by the 2010 target of the Convention on Biological Diversity, we propose a shift away from a large set of static targets towards a smaller number of specific targets. Specifically, we present three categories of targets (red, green and blue) with examples of each. These relate respectively to (1) those biodiversity outcomes that must be avoided to avert situations that are deleterious for people, (2) the highly valued biodiversity conservation priorities, and (3) an improved scientific understanding necessary for adaptive management now and into the future.Resource Type: Journal Papers
Tropical trees in the genus Aquilaria Lam. are the principal source of gaharu, one of the most valuable forest products traded internationally. Although these species are the focus of increasing conservation concern, information on their status and distribution is lacking. Information from herbarium accessions, a national forest inventory (NFI), field surveys and gaharu traders was used to assess the distribution of Aquilaria species in Indonesia, indicating population concentrations in Sumatra and eastern Kalimantan.
Given current deforestation rates, these data suggest that all Aquilaria species in Indonesia classify as Vulnerable according to the IUCN Red List criteria.Resource Type: Journal Papers
The threatened Chilean conifer Podocarpus salignus D. Don is currently the focus of ex situ conservation eorts being undertaken by the Conifer Conservation Programme of the Royal Botanic Garden Edinburgh. To assess variation within in and ex situ populations of the species, leaf material collected from four wild populations was analysed by random amplified polymorphic DNA (RAPD).
RAPD was found to be an effective tool for assessing the genetic structure of P. salignus, for providing a guide to future germplasm-sampling strategies, and for hybrid identification. Implications for genetic conservation of the species and the role of ex situ approaches are discussed.Resource Type: Journal Papers
Fagus grandifolia var. mexicana (Mexican beech) is limited to about 10 populations (2-35 ha) in the Sierra Madre Oriental, Mexico. The objectives were to assess the current status and distribution of beech by surveying five sites. Species richness varied between three to 27 tree species in the canopy, and from nine to 29 species in the understorey. Basal area of trees greater than or equal to 5 cm dbh varied between 27.87 and 70.98 m2 ha-1, and density from 370 to 1290 individual ha-1. Beech represented 22-99.6 of total basal area, and 6.8-83.3 of total density. Beech dominance varied from monodominant to codominance with Carpinus caroliniana, Quercus spp., Liquidambar styraciflua, Magnolia schiedeana, and Podocarpus spp. Beech total population size ranged from 180 to 6300 trees with a total of less than 1300 individuals in four sites. Anthropogenic disturbance remains a major threat to these forests. It is uncertain whether Mexican beech will be able to survive without conservation efforts.Resource Type: Journal Papers
In the past few years, a number of analyses have been undertaken to measure progress towards the 2010 and 2012 CBD targets. This report demonstrates how the measurement of progress is influenced by decisions on which protected areas are included (for instance, whether internationally designated sites, or sites without an assigned IUCN category are included) and which biogeographic datasets used (for instance which mountain dataset is chosen), and highlights the need for standardised methods and datasets.Resource Type: Journal Papers
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