相思人工林生物量分配格局与林下植被多样性分析

对位于漳州平和7年生的3种相思人工林生物量的分配格局和林下植被多样性进行研究,结果表明:马占相思林下植被Shannon-Wiener多样性指数最高(3.0936),黑木相思其次(3.0649),卷荚相思最低(2.2430);而与物种数目无关的Shannon均匀度指数则以黑木相思最高,表明其物种组成比较均匀;3种相思人工林林下植被群落相似性指数均在0.5~0.75之间,表现为中等相似;在3种相思人工林单株各器官生物量组成中,干材生物量所占的比例最大(55.30%~68.28%),其它组分依次为:根(14.72%~19.30%)>皮(10.59%~10.82%)>枝(3.96%~9.19%)>叶(2.42%~8.39%);3种相思人工林林下植被生物量大小顺序为:卷荚相思(6.69 t.hm-2)>马占相思(6.24 t.hm-2)>黑木相思(4.21 t.hm-2);3种相思人工林林分生物量的大小顺序为卷荚相思(75.21 t.hm-2)>黑木相思(49.19 t.hm-2)>马占相思(48.22 t.hm-2)。对3种相思人工林生物量分布格局的比较研究表明:卷荚相思生产力高,适宜在闽南山地营林生产实践中推广。

Allocation pattern of biomass and diversity analysis of the understory in Acacia plantations

The allocation pattern of biomass and the diversity of understory of three Acacia plantation,7-year-old,were studied in Pinghe,Fujian Province.The results showed that diversity indicator of Shannon-Wiener in A.mangium plantation(3.0936) was the highest,followed by A.melanoxylon stand(3.0649),and A.concinnatai stand(2.2430) was the smallest.However,the evenness indicator irrelevant with species was highest in A.melanoxylon stand which demonstrated that the more even species composition.The similarity indicator for three Acacia plantation is between 0.5 and 0.75 which belong to medium similarity.The allocation to stems was the greatest,making up 55.30%～68.28% of the sum.The order for other components: root(14.72%～19.30%) > bark(10.59%～10.82%) > branch(3.96%～9.19%) > leaf(2.42%～8.39%);For the acacia plantation,the order of understory biomass was as followed: A.concinnatai(6.69 t·hm-2) > A.mangium(6.24 t·hm-2) > A.melanaxylon(4.21 t·hm-2).Stand biomass of A.concinnatai,A.melanaxylon and A.mangium was 75.21 t·hm-2,49.19 t·hm-2,48.22 t·hm-2,respectively.Comparing with Acacia plantations each other,A.concinnatai,which has the preferable growth rate,is suitable for being extended in the forest productive practice in Southern Fujian mountain areas.