Long-term effects of mowing on plasticity and allometry of Leymus chinensis in a temperate semi-arid grassland, China

Abstract

Mowing is an important land management practice for natural semi-arid regions. A growing body of empirical evidence shows that different mowing regimes affect the functioning of grassland ecosystems. However, the responses of plant functional traits to long-term mowing and their allometric scaling under long-term mowing are poorly understood. For a better understanding of the effects of mowing on grassland ecosystems, we analyzed the allometric traits of leaves and stems of Leymus chinensis (Trin.) Tzvel., a dominant grass species in eastern Eurasian temperate grassland, at different mowing intensities (no clipping, clipping once every two years, once a year and twice a year). Experiments were conducted on plots established over a decade ago in a typical steppe of Xilinhot, Inner Mongolia, China. Results showed that most of the functional traits of L. chinensis decreased with the increased mowing intensity. The responses of leaves and stems to long-term mowing were asymmetric, in which leaf traits were more stable than stem traits. Also significant allometric relationships were found among most of the plant functional traits under the four mowing treatments. Sensitive traits of L. chinensis (e.g. leaf length and stem length) were primary indicators associated with aboveground biomass decline under high mowing intensity. In conclusion, the allometric growth of different functional traits of L. chinensis varies with different long-term mowing practices, which is likely to be a strategy used by the plant to adapt to the mowing disturbances.

Heavy grazing effects on stem elongation and internode allometry: Insights from a natural pasture grass

“…This region has a semi‐arid continental climate. Long‐term meteorological data (1980–2013) show the mean annual temperature is 0.9°C, with mean monthly temperatures ranging from 3.6°C to 19.4°C during the growing season of April to August (Li et al., ). The mean annual precipitation is 328.54 mm.…”

“…Prior to statistical analysis, the mean of each of the plant traits was calculated from measurements of three L. chinensis individuals in a single subplot. The responses of functional traits of L. chinensis between grazed and ungrazed grassland plots were assessed using the plasticity index (PI) (Li et al., ; Olmo, Lopez‐Iglesias, & Villar, ).…”

“…Allometric relationships were analyzed using the classic allometric model (Li et al., ; Warton, Duursma, Falster, & Taskinen, ):where a is the allometric coefficient and b is the allometric exponent. The Equation is usually fitted in the form log Y = l og a + b log X .…”

“…χ 2 and AIC), and the significance (i.e. significance of regression weights) of the functional trait variables within the model (Li et al., ).…”

A Multi-year Beneficial Effect of Seed Priming with Gibberellic Acid-3 (GA3) on Plant Growth and Production in a Perennial Grass, Leymus chinensis

“…Leymus chinensis , a perennial, rhizomatous grass is one of the most widely distributed types of steppe vegetation in temperate eastern Eurasia 26,27 . It is one of the species most preferred for consumption by large herbivores because of its high palatability in terms of forage value, and high crude protein 28 .…”