Limits...
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

(A) Average root biomass during growing season of 2012 and (B) belowground net primary productivity from May 2012 to May 2013 in the warmed (dashed line) and control (solid line) plots. Different letters indicate statistically significant differences at the corresponding confidence interval among the two treatments. Error bars represent the standard error for n = 5.
© Copyright Policy - creativeCommonsBy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC4588646&req=5

ece31685-fig-0003: (A) Average root biomass during growing season of 2012 and (B) belowground net primary productivity from May 2012 to May 2013 in the warmed (dashed line) and control (solid line) plots. Different letters indicate statistically significant differences at the corresponding confidence interval among the two treatments. Error bars represent the standard error for n = 5.

Mentions: The growing season average root biomasses in 2012 were 3021.74 and 3095.04 g m−2 in control and warmed plots, respectively. Infrared heaters nonsignificantly (P > 0.05) increased the total root biomass in the 0–50 cm depth by 73.30 g m−2. However, heaters caused different changes in root biomass between the upper and the deeper soil layer (Fig. 3A and Table 2). In the top soil layer (0–10 cm depth), root biomass in warmed plots was significantly (P < 0.05) lower than that in control plots (203.82 g m−2 difference). In contrast, the root biomass in 30–40 cm layer of warmed plots was significantly (P < 0.001) higher than that in control plots (141.98 g m−2 difference). Heater‐induced decreases in the upper layer root biomass and increases in the deeper root biomass resulted in the upper layer root biomass percentage of the total root biomass to decrease from 80.90% to 72.88% and increased the deeper root biomass percentage from 19.10% to 33.30%.


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)

(A) Average root biomass during growing season of 2012 and (B) belowground net primary productivity from May 2012 to May 2013 in the warmed (dashed line) and control (solid line) plots. Different letters indicate statistically significant differences at the corresponding confidence interval among the two treatments. 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-0003: (A) Average root biomass during growing season of 2012 and (B) belowground net primary productivity from May 2012 to May 2013 in the warmed (dashed line) and control (solid line) plots. Different letters indicate statistically significant differences at the corresponding confidence interval among the two treatments. Error bars represent the standard error for n = 5.
Mentions: The growing season average root biomasses in 2012 were 3021.74 and 3095.04 g m−2 in control and warmed plots, respectively. Infrared heaters nonsignificantly (P > 0.05) increased the total root biomass in the 0–50 cm depth by 73.30 g m−2. However, heaters caused different changes in root biomass between the upper and the deeper soil layer (Fig. 3A and Table 2). In the top soil layer (0–10 cm depth), root biomass in warmed plots was significantly (P < 0.05) lower than that in control plots (203.82 g m−2 difference). In contrast, the root biomass in 30–40 cm layer of warmed plots was significantly (P < 0.001) higher than that in control plots (141.98 g m−2 difference). Heater‐induced decreases in the upper layer root biomass and increases in the deeper root biomass resulted in the upper layer root biomass percentage of the total root biomass to decrease from 80.90% to 72.88% and increased the deeper root biomass percentage from 19.10% to 33.30%.

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