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  Elevational distribution of restricted range forest tree taxa in eastern Tanzania »

  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
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  Using Higher-Taxon Richness as a Surrogate for Species Richness: II. Local Applications »

  Recent analyses confirm that urgent attempts to catalogue the distribution of biological diversity may be facilitated by focusing at the level of genera or families rather than species. However, questions remain over the application of higher-taxon surveys to identify networks of priority areas for conservation action. Is the close spatial match between species and higher-taxon richness at global and regional scales reiterated when sites are locally distributed? How much money is saved by the higher-taxon approach? And how does using genus or family information affect the efficiency with which spatial priorities for conservation are identified? We examined these issues using data on the diversity of woody plants in Sri Lankan forests.

  Resource Type: Journal Papers
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  Conservation and sustainable use of tropical trees in the genus Aquilaria I. Status and distribution in Indonesia »

  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
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  Genetic variation in wild Chilean and cultivated British populations of Podocarpus salignus D. Don (Podocarpaceae) »

  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
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  Distribution and stand characteristics of relict populations Mexican beech (Fagus grandifolia var. mexicana) »

  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
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  Genetic variation in the vulnerable and endemic Monkey Puzzle tree, detected using RAPDs »

  Araucaria araucana (Monkey Puzzle), a southern South American tree species of exceptional cultural and economic importance, is of conservation concern owing to extensive historical clearance and current human pressures. Random amplified polymorphic DNA (RAPD) markers were used to characterise genetic heterogeneity within and among 13 populations of this species from throughout its natural range.

  Although populations are geographically divided into Chilean Coastal, Chilean Andes and Argentinean regions, this grouping explained only 1.77 of the total variation. Within Andean groups there was evidence of a trend of genetic distance with increasing latitude, and clustering of populations across the Andes, suggesting postglacial migration routes from multiple refugia. Implications of these results for the conservation and use of the genetic resource of this species are discussed.

  Resource Type: Journal Papers
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  Using Higher-Taxon Richness as a Surrogate for Species Richness: I. Regional Tests »

  In the first of two papers, we explored congruence between species and higher-taxon richness across protected areas in Indo-Malaya and the Pacific rim. Our results support the use of the higher-taxon approach in guiding tropical conservation, but with certain reservations. In all three groups examined, higher-taxon richness was quite closely related to species number. However, the precision with which absolute species richness of reserves could be predicted from higher-taxon richness was often surprisingly low, particularly for rich sites where surveying higher taxa rather than species would save most time. The performance of higher taxa as surrogates also dropped sharply with increasing taxonomic rank, resulting in a trade-off between time saved by high-level surveys and the value of those surveys. Lastly, we found that species richness within individual higher taxa was potentially as powerful an indicator of the overall species diversity of a site as the number of higher taxa it contained.

  Resource Type: Journal Papers
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  Reproductive ecology of Aquilaria spp. in Indonesia »

  Aquilaria spp. (Thymelaeaceae) are the principal source of Gaharu, a valuable resin, yet information about their reproductive ecology is almost entirely lacking. Individuals of six species (A. beccariana, A. crasna, A. filaria, A. hirta, A. malaccensis and A. microcarpa) in cultivation in Indonesia were investigated to assess reproductive phenology, pollination, seed production and germination. Seed production and seedling dispersion were also assessed in natural populations of A. beccariana, A. malaccensis and A. microcarpa in Kalimantan.

  The results indicate that Aquilaria spp. have high reproductive potential, but suggest that seed dispersal might be limited in natural forests. The implications of these results for the management of Aquilaria spp. are discussed.

  Resource Type: Journal Papers
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  Bombina variegata mating behavior »

  This article reports the first record of a male Bombina variegata amplecting a dead female. This observation provides additional evidence suggesting that male B. variegata do not assess females carefully before clasping them, occasionally making obvious mistakes. The benefits of being first to encounter a female probably outweigh the costs of this type of error.

  Resource Type: Journal Papers
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  Factors influencing the survival and growth of Aquilaria malaccensis seedlings in Indonesia »

  Aquilaria malaccensis (Thymelaeaceae) is the principal source of gaharu, one of the most valuable tropical forest products in international trade. Despite its economic importance, the autecology of this species is virtually unknown. Seedling growth and survival of A. malaccensis was monitored over a 15-month period in natural forest in West Kalimantan. Mean height growth rate was 21.2 + 2.3 cm year1, and was positively related to light availability (i^= 0.79, p < 0.001), but unrelated to distance to the nearest mature tree or seedling density. By the end of the observation period, fewer than 20% of seedlings surveyed initially were still alive, trampling and cutting being one of the main causes of mortality. A nursery experiment examined the influence of soil (two treatments), light availability (four treatments) and seedling density (four treatments) on growth. Although a decrease in irradiance was associated with significantly (p < 0.01, t - test) lower values for height and stem diameter, seedlings were able to survive under the low light treatment. Lower height growth rates and leaf increment were observed with higher seedling densities on the more fertile soil; no such effects of density were observed on the relatively infertile soil. The implications of these results for the sustainable management of A. malaccensis are discussed.

  Resource Type: Journal Papers