苏南丘陵区3种林分凋落叶客置分解特征  

Inter-site incubation with leaf decomposition for three forest types

作　　者：陈莉莎[1] 张金池[1] 庄家尧[1] 司登宇[1] 

机构地区：[1]南京林业大学森林资源与环境学院,江苏南京210037

出　　处：《浙江农林大学学报》2013年第5期681-688,共8页Journal of Zhejiang A&F University

基　　金：国家林业公益性行业科研专项(201104068)

摘　　要：于2010年1月至2011年5月,利用野外分解袋法在苏南丘陵区麻栎Quercus acutissima,杉木Cunninghamia lanceolata,马尾松Pinus massoniana等3种林分内进行凋落叶客置后分解速率及养分动态变化的研究。结果表明:阔叶树种分解速率大于针叶树种;分解系数k麻栎叶最高(k=0.391 4),马尾松叶居中(k=0.238 8),杉木叶(k=0.209 1)较低;分解系数k与初始氮含量显著正相关(P<0.01),与初始碳氮比(C/N)显著负相关(P<0.05),失重率分别与氮释放率(P<0.05)、磷释放率、有机碳释放率显著正相关(P<0.01),与C/N显著负相关(P<0.05);分解过程中,氮和钾总体为净释放,磷为释放或固持状态,有机碳释放率逐步上升,C/N比基本呈下降趋势。客置后分解地特征效应较显著,针叶树种凋落叶客置到阔叶林后分解速率加快,反之则减慢;养分释放速率大体表现为促进作用,而分解16个月后,不同分解地的同种凋落叶养分释放率有趋于一致的趋势;经Olson指数衰减模型模拟,客置后麻栎叶分解系数k变小,杉木叶和马尾松叶分解系数k变大,预测麻栎叶t0.50,t0.95分别延长0.09～0.20 a和0.10～0.29 a,杉木叶分别缩短0.11～0.60 a和2.91～2.97 a,马尾松叶在麻栎林分解地t0.50,t0.95分别缩短0.06 a和0.09 a,在杉木林分解地分别延长0.19 a和0.36 a。有机碳t0.50麻栎叶缩短0.09～0.11 a,杉木叶延长0.01～0.09 a,马尾松叶缩短0.07～0.08 a;有机碳t0.95麻栎叶延长0.10～0.23 a,马尾松叶缩短0.30 a,杉木叶在麻栎林分解地缩短0.01 a,在马尾松林分解地延长0.32 a。The litter bag method was used to conduct an inter-site incubation experiment to study leaf decomposition changes and nutrient release for three forest types in the hilly areas of southern Jiangsu Province from January 2010 to May 2011.The Olsen exponential model and correlation analysis were employed.Results showed that the decomposition rate（k） of broadleaf ＞coniferous species with Quercus acutissima （k =0.391 4） ＞Pinus massoniana（k =0.238 8）＞Cunninghamia lanceolata （k =0.209 1）.The initial N concentration and k were significantly and positively correlated （P＜0.01,r =0.843 0）,but k was significantly and negatively correlated to initial C/N （P＜0.05,r =-0.791 0）.Meanwhile,the weight loss rates were significantly and positively correlated to the release rates of N （P＜0.05,r =0.264 0）,P （P＜0.01,r =0.340 0）,and organic carbon （OC）（P＜0.01,r--0.910 0） but significantly and negatively correlated to C/N （P＜0.05,r =-0.766 0）.During decomposition,N and K were totally released; whereas P was released or immobilized.The OC release rate gradually increased,and the C/N value of leaf litter decreased.Inter-site incubation showed that a faster litter k occurred with coniferous species incubated in broadleaf forests and a lower k for broadleaf species incubated in coniferous forests.The Olson exponential model for leaf litter decomposition indicated that inter-site incubation decreased k for Q.acutissima and increased k for P.massoniana and C.lanceolata.After inter-site incubation for Q.acutissima,decomposition of 50％ and 95％ of the leaf litter extended 0.09-0.20 years and 0.10-0.29 years,respectively,and for C.lanceolata shortened 0.60-0.11 years and 2.91-2.97 years,respectively; however,for P.massoniana incubated in a Q.acutissima forest,decomposition shortened 0.06 years and 0.09 years,respectively,and in a C.lanceolata forest extended 0.19 years or 0.36 years,respectively.For 50％ organic carbon decomposition,incubation for Q.acutissima shortened 0.09-0.11 ye

关 键 词：森林生态学 凋落叶 客置 分解速率 养分释放 Olson指数衰减模型 

分 类 号：S718.5[农业科学—林学]