Responses of plant biomass, photosynthesis and lipid peroxidation to warming and precipitation change in two dominant species (Stipa grandis and Leymus chinensis) from North China Grasslands

Abstract

Influential factors of global change affect plant carbon uptake and biomass simultaneously. Although the effects from warming and precipitation change have been extensive studied separately, the responses of plant biomass, photosynthesis, and lipid peroxidation to the interaction of these factors are still not fully understood. In this study, we examined the physiological responses of two dominant plant species from grasslands of northern China with different functional traits to combinations of five simulated warming patterns and five simulated precipitation patterns in environment‐controlled chambers. Our results showed that the biomass, net CO 2 assimilation rate (P n), maximal efficiency of photosystem II photochemistry (F v/F m), and chlorophyll content (Chl) of Stipa grandis and Leymus chinensis were enhanced by moderate warming and plus precipitation, but they declined drastically with high temperature and drought. High temperature and drought also led to significant malondialdehyde (MDA) accumulation, which had a negative correlation with leaf biomass. The lower level of lipid peroxidation in leaves of S. grandis suggests that this species is better protected from oxidative damage under heat stress, drought stress and their interactive conditions than L. chinensis. Using the subordinate function values method, we found S. grandis to be more sensitive to climate change than L. chinensis and the gross biomass and root biomass of S. grandis and the leaf biomass of L. chinensis were most sensitive to climate change. Furthermore, the P n of both S. grandis and L. chinensis had a significant linear relationship with F v/F m and Chl, indicating that carbon assimilation may be caused by nonstomatal limitations.

Selection of Reference Genes for qRT-PCR Analysis of Gene Expression in Stipa grandis during Environmental Stresses

“…is a C3 perennial bunchgrass [1] that is distributed widely in eastern Eurasian steppes and the middle Eurasian steppe zone [2]. This species is dominant in the typical steppe of the Xilingole Plateau of Inner Mongolia [1].…”

“…The physiological responses of S . grandis to high temperature and drought have also been reported [2]. Several genetic diversity studies have been carried out on S .…”

Community carbon and water exchange responses to warming and precipitation enhancement in sandy grassland along a restoration gradient

“…Precipitation contributes to soil moisture directly by adding water to the system, which influences plant growth strongly (Yang et al, ), especially in semiarid regions (Song et al, ). Precipitation enhancement may increase photosynthesis (Song et al, ), plant community coverage (Wu et al, ), and extend the growing season (Wertin, Reed, & Belnap, ) to promote the growth of plants. However, precipitation enhancement may distribute more material to assimilate organs, and thus, roots were inhibited.…”

“…However, Shi et al () reported that warming decreased the turnover rate of the live C pool but increased the turnover rate of litter and fast soil C pool; as a result, warming decreased gross primary production and total ecosystem C. The effect of warming on optimum temperature, warming time, and water availability varies among ecosystems. At the temperature below the optimum level, warming contributes to plants; however, it was shown that temperature which is higher than optimal one for plant growth or photosynthesis produced adverse effects on plant photosynthesis, productivity, and water use efficiency (Bauweraerts et al, ; Song, Wang, & Lv, ). On the other hand, warming usually accelerates ecosystem respiration in the short term, but in the long term, responses of respiration to warming are less clear because most warming experiments are too short (Li et al, ; Rustad et al, ).…”

Contrasting responses of steppe Stipa ssp. to warming and precipitation variability

“…Each pot was filled with approximately 0.61 kg of dry chestnut soil (organic carbon content 12.3 g/kg, total nitrogen content 1.45 g/kg, and soil field capacity 24.8%-26.8%), and 10 seeds were planted per pot. All pots were first placed in glasshouse (day/night temperature of 26-28/18-20°C, maximum photosynthetic photon flux density of 1,000 mol m -2 s -1 ) and wellwatered to complete the growth of the seedlings (Lv, Zhou, Wang, & Song, 2016;Song et al, 2016). Until the third leaf emergence (about 3 weeks after sowing), the seedlings were thinned to four plants per pot.…”