**Modification in Grassland Ecology under the Influence of Changing Climatic and Land Use Conditions**

Jimin Cheng, Chengcheng Gang, Liang Guo, Wei Li, Jingwei Jin, Jishuai Su and Lin Wei

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/intechopen.69478

### Abstract

[92] Nippert JB, Knapp AK. Linking water uptake with rooting patterns in grassland spe-

[93] van Wilgen BW, Trollope WSW, Biggs HC, Potgieter ALF, Brockett BH. Fire as a driver of ecosystems variability. The Kruger Experience. In: Du Toit JT, Rogers KH, Biggs HC, editors. Ecology and Management of Savanna Heterogeneity. Washington, DC: Island

[94] Heisler JL, Briggs JM, Knapp AK, Blair JM, Seery A. Direct and indirect effects of fire on shrub density and above-ground diversity in a mesic grassland. Ecology. 2004;**85**:

[95] Ratajczak Z, Nippert JB, Hartman JC, Ocheltree TW. Positive feedbacks amplify rates of

[96] Walter H. Ecology of Tropical and Subtropical Vegetation. Edinburgh: Oliver and Boyd;

[97] Knoop WT, Walker BH. Interactions of woody and herbaceous vegetation in a southern

[98] Seymour C. Grass, rainfall and herbivores as determinants of *Acacia erioloba* (Meyer)

[100] Kellner K, Bosch OJH. Influence of patch formation in determining the stocking rate for southern African grasslands. Journal of Arid Environments. 1992;**22**:99-105

[101] Okin G. Desertification: Monitoring and Forecasting, Desertification—Introduction;

[102] van den Berg L, Kellner K. Restoring degraded patches in a semi-arid rangeland of

[103] Cairns J. Rehabilitating Damaged Ecosystems. 2nd ed. Boca Raton: Lewis Publishers;

[104] Coetzer KL, Erasmus BFN, Witkowski ETF, Bachoo AK. Land cover change in the Kruger to Canyons Biosphere Reserve (1993-2006): A first step towards creating a conservation plan for the subregion. South African Journal of Science. 2010;**106**:26-35 [105] Matsika R, Erasmus BFN, Twine W. A tale of two villages: Assessing the dynamics of fuelwood supply in communal landscapes in South Africa. Environmental Conservation.

2002. website: http://www.planetary.caltech.edu/\_arid/desert/desert.html

on woody plant inva-

woody encroachment in mesic tallgrass prairie. Ecosphere. 2011;**2**:1-14

recruitment in an African savanna. Plant Ecology. 2008;**197**:131-138

[99] Ward D. A resource ratio model of the effects of changes in CO<sup>2</sup>

South Africa. Journal of Arid Environments. 2005;**61**:497-511

African savanna. Journal of Ecology. 1985;**73**:235-253

sion. Plant Ecology. 2010;**209**:147-152

cies. Oecologia. 2007;**153**:261-272

42 Plant Ecology - Traditional Approaches to Recent Trends

Press; 2002. pp. 149-170

2245-2257

1971

1995

2013;**40**:71-83

Grasslands are important terrestrial ecosystems in China, which are mainly distributed in arid and semiarid regions. Based on the multiyear field experiments in the semiarid grassland, the effects of land use practices on grassland above- and belowground community characteristics were investigated. In addition, how the annual climate factors regulate grassland productivity was also studied to detect critical periods for grass growth. Results showed that grazing exclusion increased grassland root biomass, root length density and root surface area with declining plant species richness. After grazing exclusion, with perennial bunchgrasses being predominant in root community all the time, proportion of perennial rhizome grasses increased and proportion of perennial forbs declined. Clipping significantly decreased the annual mean soil respiration and its components. The root respiration was more sensitive to clipping than microbial respiration. Temperature increments during the early stage of the growing season (April–May) were positively correlated with aboveground productivity. However, hot and dry summer (June–July) strongly inhibited aboveground productivity. Impacts of drought and heat in August on productivity were negligible. Increased temperature and precipitation during the senescence period (September–October) and a warmer dormancy phase (November–March) were negatively correlated with productivity in the following year, while precipitation during the dormancy period had no detectable effects.

Keywords: semiarid grassland, grazing exclusion, soil respiration, climate variation, biodiversity, productivity
