凋落物输入对土壤呼吸温度敏感性的影响

Effects of litter input on the temperature sensitivity of soil respiration

目的 明确凋落物输入对土壤呼吸温度敏感性(Q_(10))的影响,对准确理解全球气候变化具有重要的意义。方法 利用已发表的47篇研究论文,从凋落物管理措施、植被类型、气候、地形、土壤理化性质等调控因素揭示凋落物输入对土壤呼吸温度敏感性的影响。结果 (1)不同底物调控下,凋落物Q_(10)显著大于土壤呼吸Q_(10),且呈现出对照Q_(10)>倍增Q_(10)>去凋Q_(10)的趋势;(2)不同植被因素条件下,Q_(10)的增加程度在不同植被类型下呈现出阔叶林>混交林>针叶林>草的趋势,且Q_(10)随着林龄的增加而增大;(3)不同气候条件下的Q_(10)随着温度的增加而呈现出逐渐降低的趋势,而随着降雨量增加Q_(10)则呈现出先增后减的趋势;(4)不同海拔梯度条件下,高海拔Q_(10)最大,而低海拔Q_(10)最低;(5)不同理化性质条件下,Q_(10)随着容重的增加而呈负相关,pH以及SOC与Q_(10)呈正相关,Q_(10)随着C∶N的增大呈现先增大后减小的趋势。结论 凋落物输入后会导致Q_(10)发生变化,但这种变化会受到植被类型、气候、地形以及土壤理化性质等因素的调控。

Purposes—To make clear the effect of litter input on the temperature sensitivity(Q_(10))of soil respiration,which is of great significance for accurately understanding global climate change.Methods—Based on 47 published research papers,the effects of litter input on the temperature sensitivity of soil respiration were revealed from the regulatory factors such as litter management measures,vegetation type,climate,topography,as well as soil physicochemical properties.Results—(1)Under the control of different substrates,litter Q_(10) was significantly higher than soil respiration Q_(10),and showed a trend of control Q_(10)>double litter Q_(10)>no litter Q_(10);(2)Under different vegetation factors,the increasing degree of Q_(10) showed a trend of broad-leaved forest>mingled forest>coniferous forest>grass under different vegetation types,and Q_(10) increased with the increase in the age of stand.(3)Q_(10) under different climatic conditions showed a gradually decreasing trend with the increase of temperature,while Q_(10) increased first and then decreased with the increase of rainfall;(4)Under different conditions of altitudinal gradient,Q_(10) at high altitude is the largest,while Q_(10) at low altitude is the lowest;(5)Under different physicochemical properties,Q_(10) is negatively correlated with the increase of bulk density,while pH and SOC are positively correlated with Q_(10),and Q_(10) increases first and then decreases with the increase of C∶N.Conclusions—Litter input will lead to the change of Q_(10),but this change will be regulated by vegetation type,climate,topography,soil physicochemical properties and other factors.