Variation in herbaceous plant thermotolerance: differences between plant functional types and relationship with leaf functional traits

Abstract

Tropical species are expected to be particularly negatively affected by the temperature increases associated with climate change. However, not much is known about the thermotolerance of tropical herbaceous plants, even though this knowledge is required for predicting their sensitivity to future warming. In this study, the thermotolerance of tropical herbaceous plants of Northern Western Ghats was measured, in order to understand how this trait varies between plant functional types, and whether it is correlated with leaf mass per area (LMA) and leaf dry matter content (LDMC). Different plant functional types showed differences in thermotolerance, with geophytes and graminoids showing higher heat tolerance than forbs. A positive correlation with LMA was also found. As LMA and functional type are related to the ecological functions of plants, these results have important implications for future climate-change induced alterations in herbaceous plant community composition and consequently, in ecological processes influenced by plants, especially carbon sink strength of vegetation.