Fire and grazing controlling a tropical tree line: Effects of long‐term grazing exclusion in Bale Mountains, Ethiopia

Variations in ecosystem function in response to land-use changes may be expected to reflect differences in the functional traits of plants. In this study, we sought to reveal the relationship between trait variability and grazing management on typical steppe in Inner Mongolia, and explore the implications of this relationship for ecosystem functioning. We measured aboveground biomass and 18 functional traits of the most abundant plant species in a grassland subject to three grazing-management regimes: long-term grazing, short-term grazing exclusion (since 2008) and long-term grazing exclusion (since 1956). Principal component analysis of the variation in species-level traits revealed trade-offs between the traits that enabled rapid acquisition of resources by fast-growing annual species and those that promoted conservation of resources by perennial grasses, especially Stipa grandis. However, there was no systematic pattern of intra-specific variation in trait values recorded among sites. Aggregation of plant functional traits to the community level revealed a gradient of responses of typical steppe to grazing exclusion. Long-term grazing favoured species whose traits indicate low forage quality and relatively low growth rate. Exclusion of grazing for several years favoured species whose traits indicate relatively high growth rate and high capacity to acquire resources. Exclusion of grazing for several decades favoured species whose morphological and physiological traits indicated low growth rates and high capacity for resource conservation. These community-level traits imply that ecosystem carbon and nutrient stores will change in response to the grazing regime. Long-term grazing will result in decreased plant carbon and nitrogen content, and will lead to carbon and nutrient loss, whereas short-term and long-term grazing exclusion are beneficial to the recovery of carbon and nutrient storage. The findings support the value of community aggregated traits as indicators of environmental or management change and for explaining changes in ecosystem function.

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Long-term ecological research in southern Brazil grasslands: Effects of grazing exclusion and deferred grazing on plant and arthropod communities

PLoS ONE ◽

10.1371/journal.pone.0227706 ◽

2020 ◽

Vol 15 (1) ◽

pp. e0227706 ◽

Cited By ~ 3

Author(s):

Pedro M. A. Ferreira ◽

Bianca O. Andrade ◽

Luciana R. Podgaiski ◽

Amanda C. Dias ◽

Valério D. Pillar ◽

...

Keyword(s):

Ecological Research ◽

Southern Brazil ◽

Arthropod Communities ◽

Grazing Exclusion ◽

Long Term Ecological Research

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Identifying drivers of root community compositional changes in semiarid grassland on the Loess plateau after long-term grazing exclusion

Ecological Engineering ◽

10.1016/j.ecoleng.2016.11.050 ◽

2017 ◽

Vol 99 ◽

pp. 13-21 ◽

Cited By ~ 5

Author(s):

Jishuai Su ◽

Guanghua Jing ◽

Jingwei Jin ◽

Lin Wei ◽

Jian Liu ◽

...

Keyword(s):

Loess Plateau ◽

The Loess Plateau ◽

Semiarid Grassland ◽

Grazing Exclusion ◽

Compositional Changes

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Modelling the long-term impacts of selective logging on genetic diversity and demographic structure of four tropical tree species in the Amazon forest

Forest Ecology and Management ◽

10.1016/j.foreco.2007.08.009 ◽

2008 ◽

Vol 254 (2) ◽

pp. 335-349 ◽

Cited By ~ 64

Author(s):

Alexandre M. Sebbenn ◽

Bernd Degen ◽

Vânia C.R. Azevedo ◽

Marivana B. Silva ◽

André E.B. de Lacerda ◽

...

Keyword(s):

Genetic Diversity ◽

Tree Species ◽

Selective Logging ◽

Tropical Tree ◽

Amazon Forest ◽

Demographic Structure ◽

Tropical Tree Species

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Soil bacterial community and functions directly respond to grazing exclusion in a Leymus chinensis steppe of Inner Mongolia, China

10.21203/rs.3.rs-48415/v1 ◽

2020 ◽

Author(s):

Han-Wen Deng ◽

Xin-Fu Bai ◽

Ping Zhu ◽

Yu-Meng Lu ◽

Lei Ji ◽

...

Keyword(s):

Bacterial Community ◽

Inner Mongolia ◽

Soil Bacterial Community ◽

Leymus Chinensis ◽

Absolute Abundance ◽

Ecological Functions ◽

Grazing Exclusion ◽

The Absolute ◽

Soil Bacterial

Abstract Background Grazing exclusion is a common grassland management strategy for restoring degraded grasslands. Its effectiveness on optimizing plant species community, increasing vegetation diversity and biomass, improving soil fertility, has been widely documented in literatures. However, little is known on the responses of the absolute abundance and the ecological functions of soil bacterial community to long-term grazing exclusion. Result In this study, the absolute abundance, diversity, and ecological functions of soil bacterial community were determined by the high-throughput absolute quantitative sequencing technology on a long-term grazing exclusion (40 years, GE) area and three free grazing areas (FGs) within a Leymus chinensis steppe of Inner Mongolia, China, and analyzed the driving forces leading to the variations in soil bacterial community and functions. Our results showed that there was significantly higher soil bacterial abundance in the GE than the FGs along with corresponding variations in vegetation and soil properties. With the decrease of vegetation aboveground biomass, the absolute abundance of soil bacterial community also decreased. Among the phyla of the soil bacterial communities, the relative abundances of Chloroflexi and Firmicutes phyla were especially lower, and that of Verrucomicrobia phylum was higher in the GE than the FGs; the absolute abundances of Euryarchaeota and Microgenomates phyla were especially higher in the GE than the FGs. Conclusions This study suggested that long-term grazing exclusion significantly increased the absolute abundance, changed soil bacterial composition, and especially enhanced bacterial motility and chemotaxis. In particular, soil organic matter was the important agent to influence and connect vegetation and soil. This work will enrich our understanding of the responses of absolute abundance, diversity, and function of the soil bacterial community to long-term grazing exclusion, and help the evaluation of grassland degradation degree and restoration strategy effectiveness.

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