Response of plant functional traits to temperature along an alpine gradient of altitude

摘要

Alpine landscapes are characterised by extreme topography and climate conditions with grassland occurring at sites higher than 2,000 m a.s.l. For alpine grassland ecosystems, temperature is the most limiting environmental factor for growth. We hypothesised that the expression of morphological plant functional traits reveals variation in growth rates along temperature gradients. Therefore, a transplantacion experiment was conducted to search for intra-specific differences of traits along a strong altitudinal gradient in Austria. Two widespread alpine grassland species (Trisetum flavescens L. and Plantago lanceolata L.) were cultivated in flower pots under greenhouse conditions and then positioned at four altitudes between 1,092 m to 1,929 m a.s.l. Leaf length (LL), plant height (PH), leaf area (LA), specific leaf area (S L A) and surface biomass were recorded during the observation period. Results clearly indicate a strong linear relationship of plant functional traits with rising altitude, mostly driven by temperature but probably also influenced by other environmental factors such as intensity of radiation.