Different growth and physiological responses to experimental warming of two dominant plant species Elymus nutans and Potentilla anserina in an alpine meadow of the eastern Tibetan Plateau

Abstract

The effects of experimental warming on the growth and physiology of grass Elymus nutans and forb Potentilla anserina were studied by using open-top chambers (OTCs) in an alpine meadow of the eastern Tibetan Plateau. The warming treatment increased mean air and soil surface temperatures by 1.53°C and 0.50°C, respectively, but it reduced soil relative water content in the surface layer. Experimental warming enhanced the growth and gas exchange of E. nutans, while it reduced those of P. anserina. Experimental warming resulted in an increased efficiency of photosystem II (PSII) in E. nutans, while decreasing it in P. anserina; significantly stimulated non-photochemical quenching, antioxidative enzymes and non-enzymes in both species; and significantly reduced malondialdehyde content in E. nutans, while promoting it in P. anserina. The results of this study indicated that the two species showed different growth responses to experimental warming and their different physiological performances further indicated that experimental warming alleviated the negative effect of low temperature on the growth and development of E. nutans, but limited the competitive ability of P. anserina in the study region.

Contrasting thermal acclimation of leaf dark respiration and photosynthesis of Antarctic vascular plant species exposed to nocturnal warming

“…This improved carbon gain mediated by enhanced photosynthesis observed in D. antactica was also correlated with increased foliar biomass (Table ), suggesting an increase in growth with warmer nights. We cannot rule out that longer exposure to warming could also increase photosynthesis and consequently foliar biomass in C. quitensis , as it has been reported for other species from arctic (Doiron et al ) and alpine (Shi et al , Fu et al ) ecosystems. Indeed, it was already reported that C. quitensis growing with in situ diurnal warming has a higher relative growth rate related with an increase in the net photosynthesis because of specific adjustment in anatomical traits associated to an increase of the internal CO 2 diffusion (Sáez et al ).…”

Plant functional traits mediate reproductive phenology and success in response to experimental warming and snow addition in Tibet

“…b, e). This high solar noon temperature may suppress photosynthesis activities (Shi et al ., ), which may cause a reduction in the maximum numbers of flowers and reproductive success of plants in our study system.…”

Response of alpine plant flower production to temperature and snow cover fluctuation at the species range boundary

“…Pyancov and Vaskovskii (1994) found a decreased number of chloroplasts in plants of Alopecurus alpinus Smith. exposed to high temperatures, whilst Shi et al (2010) showed reduced efficiency of photosynthesis in Potentilla anserina L. accompanied by oxidative stress due to accumulation of oxidative compounds. It is therefore possible that different physiological responses to temperature variations may have occurred in our species.…”

“…For instance, experimental warming enhanced the growth and gas exchange along with efficiency of photosystem II of Elymus nutans Griseb. in the Tibetan Plateau (Shi et al 2010), and in Oxyria digina (L.) Hill in the Arctic (Pyancov and Vaskovskii 1994). By contrast, prolonged exposure to high temperature can reduce the reproductive performance in many species, as a consequence of morphological modifications and the reduced activity of other physiological processes, such as photosynthesis.…”