1.key laboratory of Oasis Ecology under the Ministry of Education,College of Ecology and Environment Science,Xinjiang University;2.China;3.Institute of Forest Ecology,Xinjiang Academy of Forestry;4.Tianshan Forest Ecosystem National Station
在高纬度高海拔区域气温增幅更大的背景下，高山亚高山森林土壤有机碳稳定性组分分配比关系以及由于此差异导致对增温的反馈效应均有待深入阐释。天山森林是以雪岭云杉(Picea Schrenkiana)为单优树种的温带针叶林，在天山北坡中山带（海拔约1760—2800 m）呈垂直落差超过1000 m的带状斑块分布，便于排除混交树种的影响，而量化土壤有机碳库稳定性组分分配比关系沿海拔的分异规律，及其对气候变化的响应情况。本文沿海拔梯度设置森林样地并分层采集土样，研究各土层土壤总有机碳库（CSOC）、活性碳库（Ca）、缓效性碳库(Cs)、惰性碳库(Cp)、微生物量碳（MBC）在海拔梯度上的变化特征，通过碳库活度（A）、碳库活度指数（AI）、碳库指数（CPI）、土壤碳密度（SOCD），探讨天山森林土壤有机碳稳定性组分沿海拔的分异特征。结果表明：（1）随着海拔的升高，天山中段北坡云杉森林土壤Ca占比逐步升高，Cs和Cp占比逐步降低，这意味着天山中段北坡云杉森林土壤碳的分解释放与区域气候变暖间将呈现出加速偏离平衡态的正反馈效应；（2）该区域森林土壤的MBC和微生物熵（qMB）虽均随海拔升高呈双峰曲线，但峰值有所差异，qMB在高海拔处（2600—2800 m）显著升高，这意味着在森林高海拔区域土壤微生物的活性更强；（3）CSOC、Ca、Cs、Cp表聚效应明显，且随海拔升高呈现出单峰曲线；（4）海拔2400—2600 m的AI、CPI最大，海拔2200—2400 m的A、CPI和SOCD处于较低水平。本文对进一步深入了解天山森林土壤碳库对气候变暖的响应过程提供了科学参考，为天山森林土壤碳库管理提供了有益借鉴。
Under the background of greater temperature increase in high latitude and high elevation areas, the distribution ratio of soil organic carbon fractions in the alpine and subalpine forest and its feedback to temperature increase need to be expounded. On the Tianshan Mountains, there are temperate coniferous forests with Picea Schrenkiana as the monodominant tree species. Furthermore, on the northern slope of the middle Tianshan Mountains at an elevation range of about 1760—2800 m, the zonal and patch distribution of Picea Schrenkiana with an elevation drop of more than 1000 m makes it convenient to exclude the influence of mingled forest to determine the altitudinal distribution ratio of the soil organic carbon (SOC) fractions and the response of the distribution difference to climate change. In this study, the sampling plots were set along the altitudinal gradients, and soils were sampled from different soil layers to determine the altitudinal variation of the total soil organic carbon pool (CSOC), active carbon pool (Ca), slow carbon pool (Cs), passive carbon pool (Cp), and microbial biomass carbon (MBC). Besides, the carbon pool activity (A), carbon pool activity index (AI), carbon pool index (CPI) and soil organic carbon density (SOCD) were also determined to explore the altitudinal variation of SOC fractions on the Tianshan Mountains. The results showed that: (1) As the elevation increased, the ratio of Ca in the Picea Schrenkiana forest soil on the northern slope of the middle Tianshan Mountains grew gradually, while that of Cs and Cp gradually decreased. This indicates a positive feedback of the decomposition and release of soil carbon in the Picea Schrenkiana forest to the regional climate warming, showing an increasing deviation from the equilibrium state. (2) Although both MBC and microbial quotient (qMB) of the forest soil showed bimodal curves as the elevation increased, their peaks were different. The qMB increased significantly at high elevation (2600—2800 m), indicating the stronger soil microbial activity in the high elevation area of the forest. (3) CSOC, Ca, Cs, and Cp showed obvious topsoil aggregation and their value changes showed unimodal curves as the elevation increased. (4) The AI and CPI were the highest in the elevation range of 2400—2600 m, and the A, CPI, and SOCD were at a low level in the elevation range of 2200—2400 m. This study provides scientific reference for the further study of the responses of forest soil organic carbon pool on the Tianshan Mountains to climate warming as well as the management of the soil organic carbon pool in this area.
王珍,常顺利,王冠正,周小东,张毓涛,孙雪娇,李翔.天山中段北坡森林土壤有机碳库稳定性组分沿海拔的分异规律.生态学报,,(). http://dx. doi. org/[doi]复制