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Belowground carbon responses to experimental warming regulated by soil moisture change in an alpine ecosystem of the Qinghai-Tibet Plateau.

Xue X, Peng F, You Q, Xu M, Dong S - Ecol Evol (2015)

Bottom Line: Our results show that 3 years of warming treatments significantly elevated soil temperature at 0-100 cm depth, decreased soil moisture at 10 cm depth, and increased soil moisture at 40-100 cm depth.In contrast to the findings of previous research, experimental warming did not significantly affect NH 4 (+)-N, NO 3 (-)-N, and heterotrophic respiration, but stimulated the growth of plants and significantly increased root biomass at 30-50 cm depth.Analysis shows that experimental warming influenced deeper root production via redistributed soil moisture, which favors the accumulation of belowground carbon, but did not significantly affected the decomposition of soil organic carbon.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of Desert and Desertification Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences 320 West Donggang Road Lanzhou 730000 China.

ABSTRACT
Recent studies found that the largest uncertainties in the response of the terrestrial carbon cycle to climate change might come from changes in soil moisture under the elevation of temperature. Warming-induced change in soil moisture and its level of influence on terrestrial ecosystems are mostly determined by climate, soil, and vegetation type and their sensitivity to temperature and moisture. Here, we present the results from a warming experiment of an alpine ecosystem conducted in the permafrost region of the Qinghai-Tibet Plateau using infrared heaters. Our results show that 3 years of warming treatments significantly elevated soil temperature at 0-100 cm depth, decreased soil moisture at 10 cm depth, and increased soil moisture at 40-100 cm depth. In contrast to the findings of previous research, experimental warming did not significantly affect NH 4 (+)-N, NO 3 (-)-N, and heterotrophic respiration, but stimulated the growth of plants and significantly increased root biomass at 30-50 cm depth. This led to increased soil organic carbon, total nitrogen, and liable carbon at 30-50 cm depth, and increased autotrophic respiration of plants. Analysis shows that experimental warming influenced deeper root production via redistributed soil moisture, which favors the accumulation of belowground carbon, but did not significantly affected the decomposition of soil organic carbon. Our findings suggest that future climate change studies need to take greater consideration of changes in the hydrological cycle and the local ecosystem characteristics. The results of our study will aid in understanding the response of terrestrial ecosystems to climate change and provide the regional case for global ecosystem models.

No MeSH data available.


Related in: MedlinePlus

Average soil respiration, heterotrophic respiration, and autotrophic respiration in warmed (black bar) and control (gray bar) plots during the growing season of 2012. Different letters indicate statistically significant differences at the corresponding confidence interval among the two treatments as determined by ANOVA followed by a Tukey test. Error bars represent the standard error for n = 5.
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ece31685-fig-0005: Average soil respiration, heterotrophic respiration, and autotrophic respiration in warmed (black bar) and control (gray bar) plots during the growing season of 2012. Different letters indicate statistically significant differences at the corresponding confidence interval among the two treatments as determined by ANOVA followed by a Tukey test. Error bars represent the standard error for n = 5.

Mentions: Figure 5 shows the growing season average soil respiration values (Rs) in 2012 in control and warmed plots, respectively. Infrared heaters significantly (P = 0.004) increased Rs by 0.68 μ mol m−2 sec−1, nonsignificantly (P = 0.729) increased soil Rh by 0.07 μ mol m−2 sec−1, and significantly (P = 0.000) increased soil Ra by 0.56 μ mol m−2 sec−1.


Belowground carbon responses to experimental warming regulated by soil moisture change in an alpine ecosystem of the Qinghai-Tibet Plateau.

Xue X, Peng F, You Q, Xu M, Dong S - Ecol Evol (2015)

Average soil respiration, heterotrophic respiration, and autotrophic respiration in warmed (black bar) and control (gray bar) plots during the growing season of 2012. Different letters indicate statistically significant differences at the corresponding confidence interval among the two treatments as determined by ANOVA followed by a Tukey test. Error bars represent the standard error for n = 5.
© Copyright Policy - creativeCommonsBy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4588646&req=5

ece31685-fig-0005: Average soil respiration, heterotrophic respiration, and autotrophic respiration in warmed (black bar) and control (gray bar) plots during the growing season of 2012. Different letters indicate statistically significant differences at the corresponding confidence interval among the two treatments as determined by ANOVA followed by a Tukey test. Error bars represent the standard error for n = 5.
Mentions: Figure 5 shows the growing season average soil respiration values (Rs) in 2012 in control and warmed plots, respectively. Infrared heaters significantly (P = 0.004) increased Rs by 0.68 μ mol m−2 sec−1, nonsignificantly (P = 0.729) increased soil Rh by 0.07 μ mol m−2 sec−1, and significantly (P = 0.000) increased soil Ra by 0.56 μ mol m−2 sec−1.

Bottom Line: Our results show that 3 years of warming treatments significantly elevated soil temperature at 0-100 cm depth, decreased soil moisture at 10 cm depth, and increased soil moisture at 40-100 cm depth.In contrast to the findings of previous research, experimental warming did not significantly affect NH 4 (+)-N, NO 3 (-)-N, and heterotrophic respiration, but stimulated the growth of plants and significantly increased root biomass at 30-50 cm depth.Analysis shows that experimental warming influenced deeper root production via redistributed soil moisture, which favors the accumulation of belowground carbon, but did not significantly affected the decomposition of soil organic carbon.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of Desert and Desertification Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences 320 West Donggang Road Lanzhou 730000 China.

ABSTRACT
Recent studies found that the largest uncertainties in the response of the terrestrial carbon cycle to climate change might come from changes in soil moisture under the elevation of temperature. Warming-induced change in soil moisture and its level of influence on terrestrial ecosystems are mostly determined by climate, soil, and vegetation type and their sensitivity to temperature and moisture. Here, we present the results from a warming experiment of an alpine ecosystem conducted in the permafrost region of the Qinghai-Tibet Plateau using infrared heaters. Our results show that 3 years of warming treatments significantly elevated soil temperature at 0-100 cm depth, decreased soil moisture at 10 cm depth, and increased soil moisture at 40-100 cm depth. In contrast to the findings of previous research, experimental warming did not significantly affect NH 4 (+)-N, NO 3 (-)-N, and heterotrophic respiration, but stimulated the growth of plants and significantly increased root biomass at 30-50 cm depth. This led to increased soil organic carbon, total nitrogen, and liable carbon at 30-50 cm depth, and increased autotrophic respiration of plants. Analysis shows that experimental warming influenced deeper root production via redistributed soil moisture, which favors the accumulation of belowground carbon, but did not significantly affected the decomposition of soil organic carbon. Our findings suggest that future climate change studies need to take greater consideration of changes in the hydrological cycle and the local ecosystem characteristics. The results of our study will aid in understanding the response of terrestrial ecosystems to climate change and provide the regional case for global ecosystem models.

No MeSH data available.


Related in: MedlinePlus