Restoration effects of fertilization and grazing exclusion on different degraded alpine grasslands: Evidence from a 10-year experiment

2021 ◽  
Vol 170 ◽  
pp. 106361
Author(s):  
Ning Zong ◽  
Peili Shi ◽  
Lili Zheng ◽  
Tiancai Zhou ◽  
Nan Cong ◽  
...  
2015 ◽  
Author(s):  
Yan Yan ◽  
Xuyang Lu

Overgrazing is considered one of the key disturbance factors that results in alpine grassland degradation in Tibet. Grazing exclusion by fencing has been widely used as an approach to restore degraded grassland s in Tibet since 2004. Is the grazing exclusion management strategy effective for the vegetation restoration of degraded alpine grasslands? Three alpine grassland types were selected in Tibet to investigate the effect of grazing exclusion on plant community structure and biomass. Our results showed that species biodiversity indicators, including the Pielou evenness index, the Shannon-Wiener diversity index, and the Simpson dominance index, did not significantly change under grazing exclusion conditions. In contrast, the total vegetation cover, the mean vegetation height of the community, and the aboveground biomass were significantly higher in the grazing exclusion grasslands than in the free grazed grasslands. These results indicated that grazing exclusion is an effective measure for maintaining community stability and improving aboveground vegetation growth in alpine grasslands. However, the statistical analysis showed that the alpine grassland type plays a more important role than grazing exclusion in which influence on vegetation in alpine grasslands because the alpine grassland type had a significant effect on vegetation indicators but grazing exclusion not. In addition, because the results of the present study come from short term (5-7 years) grazing exclusion, it is still uncertain whether these improvements will be continuable if grazing exclusion is continuously implemented. Therefore, the assessments of the ecological effects of the grazing exclusion management strategy on degraded alpine grasslands in Tibet are still need long term continued research.


2014 ◽  
Vol 11 (7) ◽  
pp. 1743-1750 ◽  
Author(s):  
Y. M. Gong ◽  
A. Mohammat ◽  
X. J. Liu ◽  
K. H. Li ◽  
P. Christie ◽  
...  

Abstract. Previous work has failed to address fully the response of (autotrophic and heterotrophic) respiration to grazing in different ecosystems, particularly in alpine grasslands outside the growing season. From 2010 to 2011 a field experiment combined two methods (static closed chambers and a closed dynamic soil CO2 flux system) in alpine grasslands located in the Tianshan Mountains. We examined the effects of grazing regime on ecosystem respiration (Re) both outside (NGS) and during (GS) the growing season and determined the pattern of Re in relation to climate change. There was no significant change in CO2 emissions under grazing. Heterotrophic respiration (Rh) accounted for 78.5% of Re with short-term grazing exclusion and 93.2% of Re with long-term grazing exclusion. Re, Rh and autotrophic respiration (Ra) fluxes outside the growing season were equivalent to 12.9%, 14.1% and 11.4% of the respective CO2 fluxes during the growing season. In addition, our results indicate that soil water content played a critical role in Ra in the cold and arid environment. Both Rh and Re were sensitive to soil temperature. Moreover, our results suggest that grazing exerted no significant effect on CO2 emissions in these alpine grasslands.


2020 ◽  
Vol 108 ◽  
pp. 105680
Author(s):  
Chenjun Du ◽  
Jie Jing ◽  
Yuan Shen ◽  
Haixiu Liu ◽  
Yongheng Gao

2019 ◽  
Vol 231 ◽  
pp. 635-645 ◽  
Author(s):  
Jianshuang Wu ◽  
Meng Li ◽  
Sebastian Fiedler ◽  
Weiling Ma ◽  
Xiangtao Wang ◽  
...  

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Jianshuang Wu ◽  
Yunfei Feng ◽  
Xianzhou Zhang ◽  
Susanne Wurst ◽  
Britta Tietjen ◽  
...  

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