کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
6457750 1420854 2017 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Effects of short-term N addition on soil C fluxes in alpine Sibiraea angustata scrub on the eastern margin of the Qinghai-Tibetan Plateau
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات علم هواشناسی
پیش نمایش صفحه اول مقاله
Effects of short-term N addition on soil C fluxes in alpine Sibiraea angustata scrub on the eastern margin of the Qinghai-Tibetan Plateau
چکیده انگلیسی


- Effects of short-term N addition on soil C budget in alpine scrub.
- Fine roots play a dominant role in the soil C balance of an alpine scrub ecosystem.
- Short-term N addition increased soil C storage by increasing fine root production.
- Alpine scrub ecosystem may function as a net C sink under high N enrichment.

Although knowledge of the impact of N enrichment on soil C fluxes is scant, such information is highly critical for estimating the global C budget under elevated N deposition. To quantify the effects of short-term N addition on soil C sequestration in an alpine scrub ecosystem, we conducted a field experiment for Sibiraea angustata scrub on the eastern margin of the Qinghai-Tibetan Plateau in China. We quantified the soil C pool (0-30 cm) and C fluxes in litterfall, fine root (<2 mm diameter) production (FRP), and soil CO2 emission (heterotrophic respiration, Rh) over four years with four levels of N addition (N0; control, N20; 20, N50; 50, and N100, 100 kg N ha−1 year−1). The results showed that at control plots the total C-input (433 ± 33 g C m−2 year−1) via FRP (360 ± 34 g C m−2 year−1) and litterfall (73 ± 1 g C m−2 year−1) was close to the C-output via Rh (466 ± 5 g C m−2 year−1), which demonstrates that the S. angustata scrub soil C is at equilibrium status. However, adding N, particularly the N100 treatment, significantly affected the soil C balance; the soil became a C sink (163 ± 46 g C m−2 year−1) by increasing FRP (+63%) rather than by increasing litterfall (P > 0.05) or reducing Rh (P > 0.05). As a result, the soil C pool (0-30 cm) increased significantly. In conclusion, these results suggest that fine roots play a dominant role in the C balance of an alpine scrub ecosystem due to large C-inputs to the soil. Moreover, short-term high N enrichment causes sequestration of additional atmospheric CO2, largely because of the stimulation of fine root growth rather than increased inputs of aboveground plant litterfall or reductions in soil CO2 emission.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Agricultural and Forest Meteorology - Volume 247, 15 December 2017, Pages 151-158
نویسندگان
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