**3. Results**

### **3.1 Temperature and precipitation changes**

The annual mean air temperature had an increasing trend and increased by 1.17°C from 1982 to 2011(**Figure 2A**). In contrast with mean annual temperature, mean annual precipitation showed a decreasing trend and larger intra- and interannual variations in our study, indicating the warmer and drier climate. The mean annual precipitation from 1982 to 2011 was 425.42 mm, with markedly lower values in 1986, 1991 and 1999 and with higher values in 2003 (**Figure 2B**).

### **Figure 2.**

*Mean annual air temperature (a) and mean annual rainfall (B) of growing season, nongrowing season and entire year at Yunwu Mountain during 1982–2011.*

### **Figure 3.**

*Changes of coverage (a), number of plants (B), plant density (C) and Shannon-wiener index (D) of grassland with grazing exclusion time at 5, 10, 15, 20, 25 and 30 years.*

**141**

**Figure 4.**

*Responses of Community Structure, Productivity and Turnover Traits to Long-Term Grazing…*

Grassland coverage, plant species richness (number of plant species), plant density (number of plant individuals) and Shannon-Wiener index had similar variation tendencies during the three-decade restoration process (**Figure 3**). Initially, the coverage, plant richness, plant density and Shannon-Wiener index significantly increased. After 20 years' restoration, they reached peak values of 92.47%, 29.33

process continuing, the four indices' values decreased to 88.73%, 28.2 species m<sup>−</sup><sup>2</sup>

There were significant differences in aboveground biomass between four groups and between total aboveground biomass and total belowground biomass (**Figure 4**).

*Biomass changes of Gramineae (a), Leguminosae (B), Compositae (C), weeds (D), aboveground community (E) and belowground community (F) of grassland with grazing exclusion time at 5, 10, 15, 20, 25 and 30 years.*

and 2.47, respectively (**Figure 3**).

**3.3 Biomass changes in grassland community after grazing exclusion**

and 2.93, respectively. With grazing exclusion

,

**3.2 Vegetative ecological characteristics after grazing exclusion**

*DOI: http://dx.doi.org/10.5772/intechopen.85306*

, 161.8 individuals m<sup>−</sup><sup>2</sup>

species m<sup>−</sup><sup>2</sup>

138.7 individuals m<sup>−</sup><sup>2</sup>

*Responses of Community Structure, Productivity and Turnover Traits to Long-Term Grazing… DOI: http://dx.doi.org/10.5772/intechopen.85306*
