Understanding Forest Health with Remote Sensing -Part I—A Review of Spectral Traits, Processes and Remote-Sensing Characteristics <s> 3. <s> The high vascular plant species richness of urbanized areas in Germany is biased towards species with specific functional traits or trait states, and towards common species, as shown in the preceding chapters. The last aspect of species diversity to be analyzed here is phylogenetic diversity: In terms of species richness, an assemblage of three Poaceae species seems as diverse as an assemblage of one Poaceae, one Asteraceae and one Fagaceae species; but the former assemblage appears much less diverse when considering their phylogenetic background: The three Poaceae species belong to one family and are thus closer related to each other than the species from the three families of Poaceae, Asteraceae and Fagaceae. Phylogenetic diversity, which measures the diversity of evolutionary relationships between species, reveals these underlying patterns, and so provides valuable information for species conservation and about mechanisms of species assembly (Vane-Wright et al. 1991). <s> BIB001 </s> Understanding Forest Health with Remote Sensing -Part I—A Review of Spectral Traits, Processes and Remote-Sensing Characteristics <s> 3. <s> Although urban areas only occupy c. 2.8% of the earth's land surface, urbanization threatens biodiversity as areas of high human population density often coincide with high biodiversity. Therefore, nature conservation should concentrate on both remote areas and densely populated regions. Protecting rare plant species in rural and urban areas can contribute to the protection of biodiversity. We therefore need to understand why species are rare. Studies on causes of rarity often concentrate on either plant traits or extrinsic threats (such as habitat fragmentation or nitrogen enrichment). However, there are only a few studies that combine traits and extrinsic threats, although such analyses might clarify causes of rarity. We assessed how the affinity of vascular plant species to urban land use ('urbanity') interacts with plant traits in determining species frequency. Germany, resolution c. 12 km x 11 km. Species with a low frequency may be rare because they occur in rare habitats or because of other reasons, although their habitat is frequent. Therefore, we calculated the frequency of species corrected for habitat frequency, i.e. relative species frequency. We explained relative species frequency by the interactions of species traits and species affinity to urban land use using generalized linear models. Simultaneous autoregressive error models controlled for phylogenetic relationships of species. Relative species frequency depends on species affinity to urban land use, independent of the different interactions between traits and urbanity used as predictors. The higher the urbanity the higher is species frequency. Urbanity interacts with species preferences towards temperature and soil acidity. Moreover, dispersal, nitrogen preferences and origin explain relative species frequency, amongst others. Many rare species, especially those preferring cool or acidic habitats might already have disappeared from urban areas. Analyses that combine species traits and environmental effects can explain the causes of rarity and help to derive better conservation strategies. <s> BIB002 </s> Understanding Forest Health with Remote Sensing -Part I—A Review of Spectral Traits, Processes and Remote-Sensing Characteristics <s> 3. <s> The controls on aboveground community composition and diversity have been extensively studied, but our understanding of the drivers of belowground microbial communities is relatively lacking, despite their importance for ecosystem functioning. In this study, we fitted statistical models to explain landscape-scale variation in soil microbial community composition using data from 180 sites covering a broad range of grassland types, soil and climatic conditions in England. We found that variation in soil microbial communities was explained by abiotic factors like climate, pH and soil properties. Biotic factors, namely community-weighted means (CWM) of plant functional traits, also explained variation in soil microbial communities. In particular, more bacterial-dominated microbial communities were associated with exploitative plant traits versus fungal-dominated communities with resource-conservative traits, showing that plant functional traits and soil microbial communities are closely related at the landscape scale. <s> BIB003
Drivers, processes and stress can manifest in the molecular, genetic, epigenetic, biochemical, biophysical or morphological-structural changes of traits BIB003 BIB001 BIB002 which can lead to irreversible changes in taxonomic, structural and functional diversity in FES. These changes can be measured by spectral traits and spectral trait variations (Figure 3 ).