Altitude effects on spatial components of vascular plant diversity in a subarctic mountain tundra

Environmental gradients are caused by gradual changes in abiotic factors, which affect species abundances and distributions, and are important for the spatial distribution of biodiversity. One prominent environmental gradient is the altitude gradient. Understanding ecological processes associated wi...

Full description

Bibliographic Details
Published in:Ecology and Evolution
Main Authors: Naud, Lucy, Masviken, Johannes, Freire, Susana, Angerbjorn, Anders, Dalen, Love, Dalerum, Fredrik
Format: Article in Journal/Newspaper
Language:English
Published: Wiley Open Access 2019
Subjects:
Online Access:http://hdl.handle.net/2263/75582
https://doi.org/10.1002/ece3.5081
Description
Summary:Environmental gradients are caused by gradual changes in abiotic factors, which affect species abundances and distributions, and are important for the spatial distribution of biodiversity. One prominent environmental gradient is the altitude gradient. Understanding ecological processes associated with altitude gradients may help us to understand the possible effects climate change could have on species communities. We quantified vegetation cover, species richness, species evenness, beta diversity, and spatial patterns of community structure of vascular plants along altitude gradients in a subarctic mountain tundra in northern Sweden. Vascular plant cover and plant species richness showed unimodal relationships with altitude. However, species evenness did not change with altitude, suggesting that no individual species became dominant when species richness declined. Beta diversity also showed a unimodal relationship with altitude, but only for an intermediate spatial scale of 1 km. A lack of relationships with altitude for either patch or landscape scales suggests that any altitude effects on plant spatial heterogeneity occurred on scales larger than individual patches but were not effective across the whole landscape. We observed both nested and modular patterns of community structures, but only the modular patterns corresponded with altitude. Our observations point to biotic regulations of plant communities at high altitudes, but we found both scale dependencies and inconsistent magnitude of the effects of altitude on different diversity components. We urge for further studies evaluating how different factors influence plant communities in high altitude and high latitude environments, as well as studies identifying scale and context dependencies in any such influences. Gustavsson's stiftelse, the Swedish Polar Research Secretariat, Formas and the Spanish Ministry of Economy and Competitiveness. http://www.ecolevol.org am2020 Mammal Research Institute Zoology and Entomology