Conflicts in maintaining biodiversity at multiple scales

Biodiversity consists of multiple scales, including functional diversity in ecological traits, species diversity and genetic diversity within species, and is declining across the globe, largely in response to human activities. While species extinctions are the most obvious aspect of this, there has also been a more insidious loss of genetic diversity within species. While a vast literature concerns each of these scales of biodiversity, less is known about how different scales affect one another. In particular, genetic and species diversity may influence each other in numerous ways, both positively and negatively. However, we know little about the mechanism behind these patterns. In this issue of Molecular Ecology, Nestmann et al. (2011) experimentally explore the effect of species and functional diversity and composition of grassland plant communities on the genetic structure of one of the component species. Increasing species richness led to greater changes in the genetic composition of the focal populations over 4 years, primarily because of genetic drift in smaller population sizes. However, there were also genetic changes in response to particular plant functional groups, indicating selective differences driven by plant community composition. These results suggest that different levels of biodiversity can trade-off in communities, which may prove a challenge for conservation biologists seeking to preserve all aspects of biodiversity.     

Are molecular markers useful predictors of adaptive potential?

Estimates of molecular genetic variation are often used as a cheap and simple surrogate for a population's adaptive potential, yet empirical evidence suggests they are unlikely to be a valid proxy. However, this evidence is based on molecular genetic variation poorly predicting estimates of adaptive potential rather than how well it predicts true values. As a consequence, the relationship has been systematically underestimated and the precision with which it could be measured severely overstated. By collating a large database, and using suitable statistical methods, we obtain a 95% upper bound of 0.26 for the proportion of variance in quantitative genetic variation explained by molecular diversity. The relationship is probably too weak to be useful, but this conclusion must be taken as provisional: less noisy estimates of quantitative genetic variation are required. In contrast, and perhaps surprisingly, current sampling strategies appear sufficient for characterising a population's molecular genetic variation at comparable markers.     

PERMANENT GENETIC RESOURCES: Development and characterization of 14 polymorphic microsatellite loci in the endangered tree Euptelea pleiospermum (Eupteleaceae)

Fourteen polymorphic microsatellite loci were developed and characterized for the endangered and tertiary relict tree, Euptelea pleiospermum. A genomic DNA enrichment protocol was used to isolate microsatellite loci and polymorphism was explored using 32 individuals from one natural population. The observed number of alleles ranged from two to nine. The ranges of observed and expected heterozygosities were 0.25-1.00 and 0.22-0.85, respectively. These microsatellite markers provide powerful tools for the ongoing conservation genetic studies of E. pleiospermum.     

Habitat preference of Great Argus Pheasant (Argusianus argus) in Kayan Mentarang National Park, East Kalimantan, Indonesia

Summary Habitat preference and abundance of the Great Argus Pheasant was studied over a ten week period in the lowland forests of the Kayan Mentarang National Park, in the remote interior of Indonesian Borneo. Repeat line transect surveys, counting the number of vocalising males, were conducted in four different habitat types. Argus Pheasants were found to be most common in primary forest, and progressively less common in old and young secondary forests. Numbers of calling males were lowest in riverine forest. Argus Pheasant densities were positively correlated with a number of transect characteristics, viz. increasing tree diameter, tree height, height of the first bough and canopy cover, and with increasing remoteness. Dancing grounds were invariably located on ridges. The conservation status of the species on Borneo is briefly discussed. The Great Argus Pheasant is still widespread but thinly spread. The rapid rate of lowland forest clearance, fragmentation of once continuous habitat and increasing hunting pressure owing to increasing accessibility may become serious threats in the near future.

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Habitatpräferenz des Großen Argusfasans (Argusianus argus) im Kayan Mentarang National Park, Ost Kalimantan, Indonesien

Zusammenfassung Die Habitatpräferenz und das Vorkommen des Großen Argusfasans wurden zehn Wochen lang im Flachlandurwald des Kayan Mentarang National Park, tief im Inneren von Kalimantan, Borneo, Indonesien, untersucht. Dazu wurden in vier verschiedenen Vegetationstypen die Anzahl vokalisierender Männchen entlang von Linientransekten festgestellt. Am häufigsten waren die Vögel im Primär-Urwald, seltener in altem und noch seltener in jüngerem Sekundärwald. Am geringsten war die Anzahl rufender Männchen in den flußnahen Wäldern. Die Häufigkeit des Vorkommens war positiv korreliert mit Stammdurchmesser, Stammhöhe, Höhe des ersten dicken Astes, Dichte der Krone und Entfernung zu Ansiedlungen. Die Balzpläte befanden sich immer auf Hügeln oder Hügelrücken. Der Argusfasan ist noch immer weitverbreitet aber nirgends häufig. Das rasche Abholzen von Flachlandwäldern und die zunehmende Jagd, die durch ein neues Wegenetz immer einfacher wird, sind die wichtigsten Gefährdungsfaktoren.

     

Isolation of microsatellite loci from the endangered plant Galium catalinense subspecies acrispum (Rubiaceae)

Galium catalinense subspecies acrispum (Rubiaceae) is a state‐endangered perennial shrub endemic to San Clemente Island. Eight polymorphic microsatellite loci were isolated from G. catalinense ssp. acrispum. These loci show high levels of variability, averaging 6.5 alleles per locus and an expected heterozygosity of 0.550. One locus exhibited significant deviations from Hardy–Weinberg equilibrium (P < 0.01) and one pair of loci exhibited significant linkage disequilibrium.