發(fā)布時(shí)間：2018-06-05 23:33

  本文選題：華北落葉松 + 降雨��； 參考：《生態(tài)環(huán)境學(xué)報(bào)》2017年08期

【摘要】：近年來(lái)隨著降雨格局的變化,區(qū)域性干旱加劇,而干旱對(duì)土壤碳循環(huán)的影響情況仍不十分明確。為探究降雨減少對(duì)土壤呼吸的影響,2016年以華北落葉松(Larix principis-rupprechtii)人工林為研究對(duì)象,設(shè)置對(duì)照(CK)、減少降雨30%(W1)和減少降雨60%(W2)3個(gè)處理水平,通過(guò)人工隔離降雨模擬干旱條件對(duì)土壤呼吸速率的影響。在6—10月份生長(zhǎng)季,采用LI-8100土壤碳通量測(cè)量系統(tǒng)測(cè)定每月月中、月末土壤呼吸速率,并同時(shí)測(cè)定5 cm深度土壤溫濕度。結(jié)果表明:減少降雨60%使土壤濕度顯著降低17.8%(P0.05),而對(duì)土壤溫度的影響不顯著;減少降雨30%對(duì)土壤溫濕度的影響均不顯著;對(duì)照、減少降雨30%和減少降雨60%的平均土壤呼吸速率分別為2.45、2.29和2.16μmol·m~(-2)·s~(-1),與對(duì)照相比,減少降雨抑制了土壤呼吸,減少降雨60%使平均土壤呼吸速率降低了11.84%(P0.05),土壤呼吸通量減少了41.01 g·m~(-2),而減少降雨30%對(duì)土壤呼吸的影響不顯著;土壤呼吸速率與土壤溫度呈顯著指數(shù)相關(guān)(P0.05),土壤溫度解釋了66.2%的對(duì)照處理的土壤呼吸變異,適當(dāng)減少降雨能夠提高土壤呼吸速率與土壤溫度的相關(guān)性;在2~7℃土壤溫度下,土壤呼吸速率與土壤濕度呈顯著二元線(xiàn)性相關(guān)(P0.05),且在2~7℃土壤溫度下減少降雨提高了土壤呼吸速率和土壤濕度的相關(guān)性;在13~17℃土壤溫度下,減少降雨則降低了土壤呼吸速率和土壤濕度的相關(guān)性;減少降雨提高了土壤呼吸的溫度敏感性,且隨著降雨減少程度的增大而增大。可見(jiàn),降雨是影響華北落葉松人工林土壤呼吸的重要因子。
[Abstract]:In recent years, with the change of rainfall pattern, regional drought intensifies, but the effect of drought on soil carbon cycle is still unclear. In order to investigate the effect of rainfall reduction on soil respiration, in 2016, the Larix principis-rupprechtii plantation was used as the research object, and three treatment levels, CK, 30% rainfall and 60% W2, were set up. The effects of drought conditions on soil respiration rate were simulated by artificial rainfall isolation. During the growing season in June-October, the soil respiration rate was measured by LI-8100 soil carbon flux measurement system, and the soil temperature and humidity were measured at a depth of 5 cm. The results showed that the effect of reducing rainfall by 60% on soil moisture was significantly lower than that on soil temperature by 17.8%, but had no significant effect on soil temperature, while the effect of reducing rainfall by 30% on soil temperature and humidity was not significant. The average soil respiration rate of 30% and 60% decreased rainfall was 2.45 ~ 2.29 and 2.16 渭 mol / m ~ (-2) 路s ~ (-1) ~ (-1) ~ (-1), respectively. Compared with the control, the decrease of rainfall inhibited soil respiration. The average soil respiration rate decreased by 11.84% and the soil respiration flux decreased by 41.01 g / m ~ (-2) by 60% rainfall, but the effect of reducing rainfall by 30% on soil respiration was not significant. Soil respiration rate was significantly correlated with soil temperature (P 0.05). Soil temperature explained the variation of soil respiration in 66.2% of the control treatments. Proper reduction of rainfall could increase the correlation between soil respiration rate and soil temperature. There was a significant binary linear correlation between soil respiration rate and soil moisture, and the decrease of rainfall at 2 ~ 7 鈩，

本文編號(hào)：1983897