Abstract
Global climate change is predicted to stimulate primary production and consequently increases litter inputs. Changing precipitation regimes together with enhanced litter inputs may affect plant community composition and structure, with consequent influence on diversity and ecosystem functioning. Responses of plant community to increased precipitation and belowground litter addition were examined lasting 5 years in a semiarid temperate grassland of northeastern China. Increased precipitation enhanced community species richness and abundance of annuals by 16.8% and 44%, but litter addition suppressed them by 25% and 54.5% after 5 years, respectively. During the study period, perennial rhizome grasses and forbs had consistent negative relationship under ambient plots, whereas positive relationship between the two functional groups was found under litter addition plots after 5 years. In addition, increased precipitation and litter addition showed significant interaction on community composition, because litter addition significantly increased biomass and abundance of rhizome grasses under increased precipitation plots but had no effect under ambient precipitation levels. Our findings emphasize the importance of water availability in modulating the responses of plants community to potentially enhanced litter inputs in the semiarid temperate grassland.
Highlights
Precipitation is a major environmental factor in determining ecosystem structure and function, especially in water-limited temperate grasslands (Burke, Lauenroth, & Parton, 1997; Epstein, Burke, & Lauenroth, 2002; Zhou, Talley, & Luo, 2009), which account for about 45% of the global land surface (Saco, Willgoose, & Hancock, 2006)
The extra litter inputs are considered an environmental problem that disrupts plant interspecific competition (Wang et al, 2010); but, from a management perspective, enhanced litter inputs to the soils have been put forward as a means to reverse the loss of species diversity and promote the restoration of degraded of lands because soil fertility is mainly kept by cycling of litter nutrient in the temperate grasslands (Liu, Huang, Han, Sun, & Zhou, 2006)
Similar to increased precipitation treatment, we found no effects of litter addition on the biomass of five functional groups during the 5 years (Figure 2)
Summary
Precipitation is a major environmental factor in determining ecosystem structure and function, especially in water-limited temperate grasslands (Burke, Lauenroth, & Parton, 1997; Epstein, Burke, & Lauenroth, 2002; Zhou, Talley, & Luo, 2009), which account for about 45% of the global land surface (Saco, Willgoose, & Hancock, 2006). Empirical studies have indicated that changes in precipitation regime and their direct influence on soil water availability are a dominant factor for structuring regional and local plant community structure and composition We hypothesized that (1) increased precipitation and litter addition would significantly stimulate plant richness, abundance, and biomass of different functional groups, because water and nutrient are key factors limiting productivity in temperate grassland ecosystem (Harpole, Potts, & Suding, 2007); (2) there would be additive or synergistic effects of combined increased precipitation and litter addition on plant community composition based on the above prediction
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
