Browsing by Author "Wu, Yunga"

Abstract Forest canopies harbor extraordinary biodiversity, with Collembola being one of the most abundant arthropod taxa. However, much of the research on canopy biodiversity has focused on tropical and subtropical regions, leaving a gap in our understanding of canopy communities in temperate and boreal forests. Studying canopy Collembola along elevational gradients can be particularly informative because several environmental factors change with elevation, and these changes may mirror those seen along latitudinal gradients. To better understand and conserve canopy Collembola diversity along elevational gradients, natural forests are of particular interest. In this study, we used canopy fogging to sample canopy Collembola at four elevation sites (800–1700 m a.s.l.) on Changbai Mountain, northeastern China, representing three natural forest types. We examined changes in species richness, abundance and composition of canopy Collembola, and partitioned beta diversity into nestedness and turnover to identify processes driving changes in community composition. We identified 53 morphospecies among 10,191 individuals, with Entomobryidae and Hypogastruridae being the dominant families. The highest abundance and species richness were observed at 1400 m and remained at similar levels at 1700 m, indicating an increasing pattern with elevation. Species turnover was the main driver of changes in community composition with elevation. Our results provide insights into the shift of canopy Collembola communities across an elevational gradient in temperate boreal forests.

Abstract Filtering processes across environmental gradients can structure patterns of trait variation within communities. The community‐weighted mean (CWM) is a metric that is commonly used to indicate the directionality of such filtering processes and the optimal adaptive strategy of taxa within community. Proximity to the CWM indicates higher fitness, and deviations from this optimal value result in changes in the relative abundances of coexisting species. We investigated patterns of intraspecific trait variation in four coexisting carrion beetle species (Coleoptera: Silphidae) across elevational gradients. The study was conducted in temperate forest ecosystems with distinct natural vegetation zones ranging from 950 m to 1700 m above sea level. Of the 12 traits measured, we found that intraspecific variation ranged from 34% (body length) to 100% (ratio of elytra length, head length and head width to body length) and accounted for a larger proportion of variation than interspecific variation in 7 traits. For most traits, trait range, which indicates the niche breadth of species at a given elevation, was positively correlated with relative abundance. The CWMs of traits associated with long‐distance dispersal decreased with elevation, whereas those associated with microhabitat use showed the opposite trend. Soil temperature influenced tibia length after controlling for the effects of species identity, but soil water content had no effect on trait variation. Patterns of variation in body width and thorax width of two beetle species supported the CWM‐optimality hypothesis; however, patterns of trait variation in body width and thorax length of another species showed an opposite trend. Our study identifies several traits that can be highly variable within carrion beetle species. Such high levels of intraspecific trait variation may enable populations to adapt across a wide range of elevations and vegetation types.