Patterns of elevational beta diversity in micro‐ and macroorganisms

Abstract

Aim While ecologists have long been interested in diversity in mountain regions, elevational patterns in beta diversity are still rarely studied across different life forms ranging from micro‐ to macroorganisms. Also, it is not known whether the patterns in turnover among organism groups are affected by the degree to which the environment is modified by human activities. Location Laojun Mountain, Yunnan Province, China. Methods The beta diversity patterns of benthic microorganisms (i.e. diatoms and bacteria) and macroorganisms (i.e. macroinvertebrates) in a stony stream were simultaneously investigated between elevations of 1820 and 4050 m. Data were analysed by using a distance‐based approach and variation partitioning based on canonical redundancy analysis. Results Analyses of community dissimilarities between adjacent sampling sites showed comparable small‐scale beta diversity along the elevational gradient for the organism groups. However, bacteria clearly showed the lowest elevational turnover when analyses were conducted simultaneously for all pairwise sites. Variation partitioning indicated that species turnover was mostly related to environmental heterogeneity and spatial gradients including horizontal distance and elevation, while purely human impacts were shown to be less important. Main conclusions The elevational beta diversity at large scales was lower for bacteria than for eukaryotic microorganisms or macroorganisms, perhaps indicative of high dispersal ability and good adaptability of bacteria to harsh environmental conditions. However, the small‐scale beta diversity did not differ among the groups. Elevation was the major driver for the turnover of eukaryotic organisms, while the turnover of bacteria was correlated more with environmental variation.

Spatial and temporal variability of bacterial communities in high alpine water spring sediments

“…This fact is in agreement with previous studies carried out on glacier streams [12,21,41,42], although our data show that this difference is not detectable later in the summer. Possible explanations for the higher beta diversity in high altitude springs in June may lie in the rapid turn-over dynamics of prokaryotes, and increased carbon availability in higher springs due to melting of glacier snow cover that mainly affects springs closer to the glacier terminus [41]. On the other hand, in late summer, different dynamics occur, such as the decrease in water deriving from snow cover melting, and the consequential increase in water from glacier ice melting and major eukaryotic competition and predation.…”

Phylogenetic beta diversity in bacterial assemblages across ecosystems: deterministic versus stochastic processes

“…This high elevational turnover rate of bacteria is also consistent with the results for diatoms and macroinvertebrates in the same streams (Wang et al, 2012b). On the other hand, high turnover across elevations for bacteria is somewhat different from a previous result obtained using denaturing gradient gel electrophoresis along the same elevational gradient, which showed no significant elevational distance-decay relationship (Wang et al, 2012b). This difference may have resulted from different resolution of the two methods: a method with lower resolution may fail to detect a significant distance-decay relationship because of undetected endemism (Morlon et al, 2008;Hanson et al, 2012).…”

“…Our results are consistent with this observation: turnover rate was significantly higher for the biofilm bacterial communities in mountainside streams than for other habitat types (except subsurface environments). This high elevational turnover rate of bacteria is also consistent with the results for diatoms and macroinvertebrates in the same streams (Wang et al, 2012b). On the other hand, high turnover across elevations for bacteria is somewhat different from a previous result obtained using denaturing gradient gel electrophoresis along the same elevational gradient, which showed no significant elevational distance-decay relationship (Wang et al, 2012b).…”

How do freshwater organisms cross the “dry ocean”? A review on passive dispersal and colonization processes with a special focus on temporary ponds

“…water surface, depth) to be colonized and its hydroperiod length, and (iv) the structure of the receiving community (see next subchapter). However, also regional factors related to altitude distribution of water bodies (Catalán et al, 2009;Wang et al, 2012), as well as the spatial distance among water bodies, and thus their isolation and density in a given territory, may act as important filters (Soininen et al, 2007;Ripley & Simovich, 2009 and literature therein) influencing colonization success.…”