Decomposing the land-use specific response of plant functional traits along environmental gradients

Veronika Fontana; Marina Kohler; Georg Niedrist; Michael Bahn; Ulrike Tappeiner; Georg Frenck

doi:10.1016/j.scitotenv.2017.04.245

Decomposing the land-use specific response of plant functional traits along environmental gradients

Sci Total Environ. 2017 Dec 1:599-600:750-759. doi: 10.1016/j.scitotenv.2017.04.245. Epub 2017 Jun 6.

Authors

Veronika Fontana¹, Marina Kohler², Georg Niedrist¹, Michael Bahn³, Ulrike Tappeiner⁴, Georg Frenck⁴

Affiliations

¹ Institute for Alpine Environment, Eurac Research, Viale Druso 1, 39100 Bozen/Bolzano, Italy.
² Institute of Ecology, University of Innsbruck, Sternwartestrasse 15, 6020 Innsbruck, Austria. Electronic address: marina.kohler@uibk.ac.at.
³ Institute of Ecology, University of Innsbruck, Sternwartestrasse 15, 6020 Innsbruck, Austria.
⁴ Institute for Alpine Environment, Eurac Research, Viale Druso 1, 39100 Bozen/Bolzano, Italy; Institute of Ecology, University of Innsbruck, Sternwartestrasse 15, 6020 Innsbruck, Austria.

PMID: 28499223
DOI: 10.1016/j.scitotenv.2017.04.245

Abstract

Environmental conditions affect functional trait variability within communities and thus shape ecosystem properties. With the ability of plants to adapt morphologically and physiologically to changing abiotic conditions, gradient analysis was shown to be a suitable tool to identify the drivers which determine trait values. Apart from direct environmental drivers and indirect gradients such as elevation, also anthropogenic effects (e.g. irrigation, grazing) can influence trait variability. Our aim was to assess the interactive effects of different environmental drivers on major plant traits and to investigate how these are modulated within two different land-use types (hay meadow vs. pasture). An elevational gradient spanning 1000m was decomposed into its underlying direct components (temperature, water input, length of growing season) for the investigation of gradual responses of five prominent functional traits (aboveground dry weight (AGDW), vegetative height (VegHt), specific leaf area (SLA), leaf dry matter content (LDMC), leaf nitrogen concentration (LNC)) for key species from two functional groups (grasses, forbs) in the two land-use/management regimes. The present study revealed that the detailed analysis of single direct gradients provides substantial additional information on trait response which remains hidden or is even reversed if only indirect gradients such as elevation are analysed. However, trait response to the combination of the three direct gradients aligned surprisingly well with trait response to the indirect gradient underpinning the adequate representation of temperature, water input and length of growing season by elevation. The response of traits significantly depended on the management regime and corresponding intensity which was shown to play an overriding role and constrained and attenuated response ranges of traits to climatic gradients.

Keywords: Alpine grasslands; Direct abiotic gradient; Elevational gradient; Management intensity; Pasture; Variability.