第二代桉树人工纯林和混交林土壤呼吸及其组分研究  

Study on the Soil Respiration and Its Components of the Second Rotation Eucalyptus Plantations in Subtropical China

作　　者：黄雪蔓[1] 刘世荣[1] 尤业明[2] 

机构地区：[1]中国林业科学研究院森林生态环境与保护研究所,国家林业局森林生态环境重点实验室,北京100091 [2]北京林业大学森林培育与保护教育部重点实验室,北京100083

出　　处：《林业科学研究》2014年第5期575-582,共8页Forest Research

基　　金：林业公益行业科技科研重大专项(200804001;201104006)

摘　　要：以广西凭祥中国林业科学研究院热带林业实验中心第二代桉树人工纯林(PP2)及其与降香黄檀混交的混交林(MP2)为研究对象,采用壕沟法,利用LI-8100土壤呼吸测定系统,对两种林分土壤呼吸组分进行分离研究。结果表明:PP2和MP2土壤呼吸速率及其各呼吸组分季节变化与土壤5 cm处的温度季节变化相似,峰值出现在6—8月份,谷值出现在12月底至次年1月初,土壤呼吸速率与土壤含水量无关;PP2全年土壤总呼吸为1 147.41 g·m-2,比MP2(844.07 g·m-2)增加了26.44%,MP2的自养呼吸(RR)累积量(136.87 g·m-2)比PP2(506.72 g·m-2)降低72.99%,而其异养呼吸(RH)累积量(707.21 g·m-2)却比PP2(640.69 g·m-2)增加了10.38%。纯林和混交林的细根生物量差异以及土壤有机质含量、凋落物有机质含量、土壤C/N、凋落物量和凋落物C/N的不同是导致自养呼吸和异养呼吸产生差异的主要原因。In order to determine the seasonal pattern of respiration and elucidate the contribution of respiration com- ponents and their control factors in Eucalyptus plantations, comparative experiments and the trenching plot method with LI-8100 automated CO2 flux system were used to quantify the components of soil respiration in three-4-year-old second rotation pure plantations （PP2） of Eucalyptus and three 4-year-old second rotation mixed Eucalyptus urophyl-la and Dalbergia odorifera plantations （MP2） in Guangxi Zhuang Autonomous Region, southern China. The results showed that there were similar seasonal dynamics for the respiration and its compoments in both the plantations. Thetotal respiration （Rs ）, heterotrophic respiration （RH） , and autotrophic respiration （RR ） varied markedly during the year with the highest rates between June to August, and the lowest rates between December to January. The soiltemperature was the main factor that affected Rs and its components, while there was no significant relationship be- tween soil water content and soil respiration flux. The estimated Rs, RR and RH values for PP2 were 1147.41 g·m^-2 , 506.72 g· m^-2 and 640.69 g· m^-2 respectively in average, and the estimated Rs, RR and R, values for MP2were 844.07 g· m^-2, 136.87 g· m^-2 and 707.21 g· m^-2 in average. The estimated Rc increased from 56.03% in the PP2 to 83.94% in the MP2. There was significant correlation between litterfall mass, fine root biomass, C/N ratio of litterfall and Rs and RR. However, there was just significant relationship between RH and total organic car- bon of soil and litterfall.

关 键 词：桉树人工林 固氮树种 土壤呼吸 异养呼吸 自养呼吸 

分 类 号：S792.39[农业科学—林木遗传育种]