黄土区辽东栎群落细根生物量对物种多样性及气候的响应  

Effects of Species Diversity and Environmental Gradients on Fine Root Biomass of Quercus liaotungensis Forest in the Loess Region

作　　者：邓磊 关晋宏[3] 高万里 杜盛 张文辉[3] 朱春云[1,2] DENG Lei;GUAN Jin-hong;GAO Wan-li;DU Sheng;ZHANG Wen-hui;ZHU Chun-yun(Academy of Agriculture and Forestry Sciences,Qinghai University,Xining,Qinghai 810016,China;College of Forestry,Northwest A&F University,Yangling,Shaanxi 712100,China;Qinghai Plateau Key Laboratory of Tree Genetics and Breeding,Xining,Qinghai 810016,China;Dongxia Forestry Farm in Datong County of Qinghai Province,Xining,Qinghai 810104,China)

机构地区：[1]青海大学农林科学院,青海西宁810016 [2]青海高原林木遗传育种重点实验室,青海西宁810016 [3]西北农林科技大学林学院,陕西杨陵712100 [4]青海省大通县东峡林场,青海西宁810104

出　　处：《西北林学院学报》2018年第5期16-22,共7页Journal of Northwest Forestry University

基　　金：中国博士后科学基金(2015M580877);国家重点研发计划“高寒丘陵区林草植被的结构优化与功能提升技术”(2017YFC0504604);青海省农林科学院创新基金(2017-NKY-02)。

摘　　要：以陕西黄龙、甘肃子午岭、宁夏六盘山和青海孟达辽东栎(Quercus liaotungensis)次生中龄林为研究对象,采用根钻取土芯法收集细根,分析群落细根生物量分布的差异,以及与群落物种多样性和气候的相互关系。结果表明,黄土区辽东栎分布中心的黄龙和子午岭地区群落细根生物量显著高于分布边缘的六盘山和孟达地区(P<0.05);群落细根主要集中在0~20cm表层土壤中,占细根总生物量的60%~80%。黄龙地区细根生物量最大(821.58g·m^(-2))、孟达地区细根生物量最小(495.30g·m^(-2))。分析还表明,辽东栎林0~20cm活细根生物量、0~20cm死细根生物量与群落丰富度指数、Shannon-Wiener多样性指数、Simpson多样性指数、Pielou均匀度指数和年均温呈正相关;与较高的降雨量、海拔呈负相关。不同地区辽东栎群落细根分布的差异表明群落地下生物量分配模式不同,需要在今后研究中深入探索分配差异的机理,为物种多样性影响生态系统碳循环的激发效应提供基础。Fine roots(diameter≤2 mm)contribute significantly to carbon cycling in forest ecosystems because they compromise a large fraction of annual net primary production.However,effects of both species diversity and environmental gradients on fine root biomass have less been investigated.In this contribution,a set of 12 sample plots were conducted in middle-aged Quercus liaotungensis forest in 4 regions of Huanglong Mountains(Shaanxi),Ziwuling Mountains(Gansu),Liupanshan Mountains(Ningxia)and Mengda Nature Reserve(Qinghai)across the Loess region.Fine roots were collected using a cylindrical(9 cm diameter)soil corer in each sample plot.The vertical distribution of fine root biomass in different sites and their relationships with community diversity and environmental factors were analyzed.The results showed that the total fine root biomass of the central distribution area in Huanglong Mountains and Ziwuling Mountains were significantly higher than those in the marginal distribution area in Liupanshan Mountains and Mengda(P<0.05).Fine root biomass was mainly distributed in 0-20 cm soil layers,which accounted for 60%-80%of the total fine root biomass.The highest fine root biomass was existed in Huanglong Mountains(821.58 g·m-2)while the lowest was in Mengda(495.30 g·m-2).Redundancy analysis showed that there was a significant relationship between species richness,Shannon-Wiener index,Simpson index,Pielou index and 0-20 cm fine root biomass and necromass,whereas a negative relationship between precipitation,elevation and 0-20 cm fine root biomass.We concluded that patterns of belowground biomass allocation differed from regions,more attention should be paid to the mechanism about the effects of species diversity on the priming effect in forest ecosystem carbon cycling.

关 键 词：辽东栎 细根生物量 群落物种多样性 黄土区 经度变化 

分 类 号：S792.18[农业科学—林木遗传育种]