论文部分内容阅读
研究了福建三明 2 7a生杉木观光木混交林和杉木纯林群落细根 (d <2mm)的生产力、分布和养分归还 .结果表明 ,混交林细根生物量、N、P养分现存量分别为 5 .381thm-2 、4 8.0 85kghm-2 和 4 .174kghm-2 ,分别比杉木纯林增加17.4 %、2 7.2 %和 2 0 .0 % .混交林细根的年净生产力达 4 .12 4thm-2 a-1,比纯林高出 16 .9% .混交林杉木和观光木细根均在表层土壤富集 ,而在较深层土壤两者分布具镶嵌性 ;与混交林杉木相比 ,纯林杉木土壤表层细根量较少 ,最大分布层次下移 .混交林中观光木细根的周转速率为 1.16 ,杉木为 0 .96和 0 .95 ;而林下植被层细根周转速率 (1.4 6～ 1.5 2 )均高于相应的乔木层 .混交林细根的年死亡量、N和P养分年归还量分别达 2 .119thm-2 、18.5 5 9kghm-2 和 1.5 6 5kghm-2 ,分别是纯林的 1.2 1倍、1.2 3倍和 1.14倍 ,其中林下植被细根占有较为重要位置 .对细根分布与土壤性质的相关分析表明 ,细根的垂直分布与土壤全N的相关性最强 (0 .87～ 0 .89) .图 1表 4参 32
The productivity, distribution and nutrient return of the fine roots (d <2mm) in the mixed forest of Chinese fir and Chinese fir in Sanming 2 aa were studied. The results showed that the contents of fine root biomass, N and P nutrients in mixed forest were 5. 381thm-2, 4 8.085kghm-2 and 4.174kghm-2 increased by 17.4%, 7.2% and 20.0% respectively compared with pure Chinese fir plantations. The annual net net productivity of fine roots in mixed forest reached 4.12. 1, 16.9% higher than the pure forest.The fine roots of mixed forest and sightseeing wood were all enriched in the surface soil, while those in the deeper soil were inlaid. Compared with the mixed forest, The fine root amount of the surface layer was less and the maximum distribution level was shifted downwards.The turnover rate of fine roots of tourist plants in mixed forest was 1.16 and that of Chinese fir was 0.96 and 0.95, 2) were higher than that of the corresponding tree layer.The annual mortality of fine roots in mixed forest was 2.119thm-2, 18.559kghm-2 and 1.56 5kghm-2, respectively, which were 1.2 1-fold, 1.2-fold and 1.14-fold, respectively, in which the fine roots of understory vegetation occupy a more important position.Correlation between fine root distribution and soil properties Showed vertical distribution of fine roots and soil total N strongest correlation (0.87 ~ 0.89). FIG. 1 Refs. 32