Root-induced alterations in soil hydrothermal properties in alpine meadows of the Qinghai-Tibet Plateau

Abstract. Climate warming and engineering activities have various impacts on the thermal regime of permafrost in alpine ecosystems of the Qinghai–Tibet Plateau. Using recent observations of permafrost thermal regimes along the Qinghai–Tibet Highway and Railway, the change of such regimes beneath embankments constructed in alpine meadows and steppes are studied. The results show that alpine meadows on the Qinghai–Tibet Plateau can have a controlling role within engineering construction effects on permafrost beneath embankments. The artificial permafrost table (APT) beneath embankments is predominantly controlled by alpine ecosystems, but the change rate of APT is not closely related with those ecosystems; it is mainly related with cooling effects of railway ballast and heat absorption effects of asphalt pavement. Variation of soil temperature beneath embankments is independent of alpine ecosystems, but variation of mean annual soil temperature with depth is closely related to those ecosystems. The vegetation layer in alpine meadows can have an insulation role within engineering activity effects on permafrost beneath embankments. This insulation role is an advantage for alleviating permafrost temperature rise in the short term, but a disadvantage in the long term because of climate warming, suggesting that vegetation layer in alpine meadow should be removed upon initiating engineering construction.

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Nutrients available in the soil regulate the changes of soil microbial community alongside degradation of alpine meadows in the northeast of the Qinghai-Tibet Plateau

The Science of The Total Environment ◽

10.1016/j.scitotenv.2021.148363 ◽

2021 ◽

pp. 148363

Author(s):

Haiyun Li ◽

Yizhi Qiu ◽

Tuo Yao ◽

Dongrong Han ◽

Yamin Gao ◽

...

Keyword(s):

Microbial Community ◽

Soil Microbial Community ◽

Tibet Plateau ◽

Alpine Meadows ◽

Soil Microbial ◽

Qinghai Tibet Plateau

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Soil degradation influences soil bacterial and fungal community diversity in overgrazed alpine meadows of the Qinghai-Tibet Plateau

Scientific Reports ◽

10.1038/s41598-021-91182-7 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Lin Dong ◽

Jingjing Li ◽

Juan Sun ◽

Chao Yang

Keyword(s):

Fungal Diversity ◽

Soil Degradation ◽

Belowground Biomass ◽

Control Site ◽

Plant Litter ◽

Community Diversity ◽

Tibet Plateau ◽

Alpine Meadows ◽

Soil Bacterial ◽

Qinghai Tibet Plateau

AbstractOver half of the alpine meadows in the Qinghai-Tibet Plateau (QTP) are degraded due to human activities. Soil degradation from overgrazing is the most direct cause of grassland degradation. It is thus important to synthesize the effects of multiple soil degradation indicators on the belowground biomass of plants and soil microorganisms in the degraded QTP. We studied the diversities and structures of soil bacterial and fungal communities using soil bacterial 16S rRNA and the fungal ITS gene under four degradation gradients, D1: lightly degraded, D2: moderately degraded, D3: highly degraded, and a non-degraded control site (CK). The bacterial Shannon diversity in D3 was significantly lower than that in D1 (p < 0.001), and the bacterial richness index in D3 was significantly lower than that in D1 (p < 0.001). There was no difference in soil fungal diversity among the different degradation levels; however, soil fungal richness decreased significantly from CK to D3. The phyla Actinobacteria, Acidobacteria and the genus Mortierella were differed significantly under the four degradation gradients. Plant litter mass and root C/N ratio were important factors associated with bacterial and fungal diversity and richness. These results indicated that alpine meadow degradation can lead to variations in both microbial diversity and the potential functioning of micro-organisms in the QTP.

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