Impact of grassland contract policy on soil organic carbon losses from alpine grassland on the Qinghai-Tibetan Plateau

2017 ◽  
Vol 33 (4) ◽  
pp. 663-671 ◽  
Author(s):  
J. Cao ◽  
Y. Gong ◽  
E. T. Yeh ◽  
N. M. Holden ◽  
J. F. Adamowski ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Alpine Grassland ◽  
Contract Policy ◽  
Carbon Losses

scholarly journals Soil age and soil organic carbon content shape biochemical responses to multiple freeze–thaw events in soils along a postmining agricultural chronosequence

2021 ◽  
Author(s):  
Christoph Rosinger ◽  
Michael Bonkowski
Keyword(s):  
Microbial Biomass ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Carbon Content ◽  
Organic Carbon Content ◽  
Freeze Thaw ◽  
Biochemical Responses ◽  
Microbial Responses ◽  
Soil Age ◽  
Carbon Losses

AbstractFreeze–thaw (FT) events exert a great physiological stress on the soil microbial community and thus significantly impact soil biogeochemical processes. Studies often show ambiguous and contradicting results, because a multitude of environmental factors affect biogeochemical responses to FT. Thus, a better understanding of the factors driving and regulating microbial responses to FT events is required. Soil chronosequences allow more focused comparisons among soils with initially similar start conditions. We therefore exposed four soils with contrasting organic carbon contents and opposing soil age (i.e., years after restoration) from a postmining agricultural chronosequence to three consecutive FT events and evaluated soil biochgeoemical responses after thawing. The major microbial biomass carbon losses occurred after the first FT event, while microbial biomass N decreased more steadily with subsequent FT cycles. This led to an immediate and lasting decoupling of microbial biomass carbon:nitrogen stoichiometry. After the first FT event, basal respiration and the metabolic quotient (i.e., respiration per microbial biomass unit) were above pre-freezing values and thereafter decreased with subsequent FT cycles, demonstrating initially high dissimilatory carbon losses and less and less microbial metabolic activity with each iterative FT cycle. As a consequence, dissolved organic carbon and total dissolved nitrogen increased in soil solution after the first FT event, while a substantial part of the liberated nitrogen was likely lost through gaseous emissions. Overall, high-carbon soils were more vulnerable to microbial biomass losses than low-carbon soils. Surprisingly, soil age explained more variation in soil chemical and microbial responses than soil organic carbon content. Further studies are needed to dissect the factors associated with soil age and its influence on soil biochemical responses to FT events.

Soil organic carbon pool along different altitudinal level in the Sygera Mountains, Tibetan Plateau

2016 ◽  
Vol 13 (3) ◽  
pp. 476-483 ◽  
Author(s):  
He-ping Ma ◽  
Xiao-lin Yang ◽  
Qi-qiang Guo ◽  
Xin-jun Zhang ◽  
Chen-ni Zhou
Keyword(s):  
Tibetan Plateau ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Carbon Pool ◽  
Organic Carbon Pool

Storage, patterns and controls of soil organic carbon in the alpine shrubland in the Three Rivers Source Region on the Qinghai-Tibetan Plateau

CATENA ◽  
2019 ◽  
Vol 178 ◽  
pp. 154-162 ◽  
Author(s):  
Xiuqing Nie ◽  
Lucun Yang ◽  
Fan Li ◽  
Feng Xiong ◽  
Changbin Li ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Source Region ◽  
Three Rivers ◽  
Storage Patterns
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