Woolly and overlapping leaves dampen temperature fluctuations in reproductive organ of an alpine Himalayan forb

Abstract

Aims: Studying the ecological significance of highly specialized morphological traits evolved by alpine plants could help us to understand the adaptation and evolution of these plants under severe alpine environment. We explored the adaptive significance of woolly and overlapping leaves for reproduction in Eriophyton wallichii, a perennial herb native to the subnival belt of the Himalaya-Hengduan Mountains. Methods: We examined whether the trichomes could influence the leaf wettability, temperature and leaf reflectance spectra in the lab. And we investigated the thermal benefits of the woolly and overlapping leaves for flowers and fruits in the field. Pollen viability and seed germination were also examined in the lab to assess whether these leaves enhance reproductive fitness. Important Findings: Our results showed that dense trichomes impart good water repellency, absorption of solar radiation and accumulation of leaf heat. The woolly and overlapping leaves increased the interior temperature of flowers and fruits to an optimal level on sunny hours, but prevented them from overheating when transient intense solar radiation occurs. This kept optimal temperatures in plants' reproductive organs, thus promoting the development of pollen and seed in alpine environment.