Vol17 No.3: 542-555
【Title】Microtopography driven plant species composition in alpine region: a fine-scale study from Southern Norway
【Author】BHATTARAI Prakash1,2*, BHATTA Kuber Prasad3, ZHANG Yang-jian1, VETAAS Ole Reidar4
【Addresses】1 Key Laboratory of Ecosystem Network Observation and Modelling, Institute of Geographic Sciences and Natural Resources Research, Beijing 100101, China; 2 University of Chinese Academy of Sciences, Beijing 100049, China; 3 Department of Biological Sciences, University of Bergen, Bergen, N-5020, Norway; 4 Department of Geography, University of Bergen, Bergen, N-5020, Norway
【Corresponding author】BHATTARAI Prakash
【Citation】Bhattarai P, Bhatta KP, Zhang YJ, et al. (2020) Microtopography driven plant species composition in alpine region: a fine-scale study from Southern Norway. Journal of Mountain Science 17(3). https://doi.org/10.1007s/11629-019-5488-6
【Abstract】This study explores the relationship between the species composition of lichen and vascular plant species with microtopography at fine scale. We conducted our study in Hardengervidda National Park, Norway. Specifically, we aim to test whether the species richness of different plant life-forms peaks at middle of the microtopography gradient, and then explain the observed patterns with an aid of snow cover gradient along microtopography and snow cover.We sampled 69 species of vascular plants and lichens in 151 plots of 4 m2 along 23 transects during summer on Tronsbu, Sandhaug and Besso. Detrended correspondence analysis (DCA) was performed to explore how microtopographical gradient was related to the variation in the species composition. One-way ANOVA was performed to test the microtopographic variability in species richness. Afterwards, generalized linear model (GLM) was used to reveal species richness patterns along the snow cover gradient.The first axis in DCA represents the complex gradient from snow free ridge to wet snowbed habitats and the second axis represents a gradient from acidic to calcareous sites. Lichen's species richness is greater in ridge than in snowbeds, while all other life forms follow the opposite trend. Species richness for total plant species, vascular plant species and herbaceous plant species increased with increase in weighted average snow indicator value (WASI), whilst species richness for lichen species declined substantially towards the maximum WASI value. In contrast, species richness for dwarf shrub species showed a unimodal relationship with WASI. This study shows that liquid water availability provides a good potential explanation for species composition and richness in mountains, which is controlled by snow cover and prevalent wind direction.
【Keywords】Species richness; Water energy dynamics hypothesis; Weighted average snow indicator value; Microtopography; Ordination