Intra-specific genetic diversity and ecophysiological performance of the aeroterrestrial green alga Klebsormidium (Klebsormidiophyceae, Streptophyta) in biological soil crusts along a gradient of land-use intensity
Final Report Abstract
Members of Klebsormidium occur in the majority of the sampled grassland and forest plots, in most cases in association with biological soil crusts. These microbiotic crusts represent typical pioneer communities, particularly in disturbed environments, that can be characterized as “ecosystem-engineers” forming water-stable aggregates that have important, multi-functional ecological roles in primary production, in nutrient and hydrological cycles, mineralization, weathering and stabilization of soils. The discovery of low genetic diversity among the isolated Klebsormidium strains was unexpected concerning the biodiversity of terrestrial microalgae and represented a clear exception compared to other algal groups. Many studies have shown that, for example, the genetic diversity of terrestrial coccoid green algae is much higher than expected and hence demonstrate in most cases a high hidden diversity (‘cryptic species’). Therefore, it turned out that Klebsormidium is a difficult genus to detect the influence of land-use intensity on the distribution and biodiversity of terrestrial microalgae. Other genera such as Chlamydomonas and its relatives should be chosen in future studies as more suitable candidates. However, the effects of land-use intensity on the biodiversity of terrestrial microalgae and cyanobacteria should be studied not only by selected single genera or species, the whole algal community should be investigated using culture-dependent and metagenomic methods.
