茂名大雾岭中次生林植被蚯蚓多样性的空间特征

在样方调查的基础上,研究大雾岭天然次生林中大田顶、茄顶两座山东、南、西、北四个坡向植物多样性、蚯蚓多样性和土壤有机质含量。结果表明:大雾岭天然次生林1)乔木总数以南坡偏低,在大田顶、茄顶南坡分别0Ind·m^-2和0.06Ind·m^-2;各坡向乔木Shannon-Weaver指数在0～2.24之间,Margalef指数在0～3.15之间,乔木多样性指数没有坡向差异;2)灌木总数没有坡向差异,灌木多样性指数南坡最低,Shannon-Weaver指数与Margalef指数在大田顶南坡分别为1.52和1.70,在茄顶南坡则分别为2.05和2.33;3)草本植物总数以南坡最高,在大田顶、茄顶南坡分别有87Ind·m^-2与244Ind·m^-2;草本植物多样性指数以南坡较高,其中Shannon-Weaver指数与Margalef指数在大田顶南坡分别为2.46与3.36;4)蚯蚓总数以南坡偏低,在大田顶与茄顶分别为7Ind·m^-2和0Ind·m^-2;各坡向蚯蚓Shannon-Weaver指数在0～1.63之间,Margalef指数在0～2.20之间,蚯蚓多样性指数没有坡向差异:5)土壤有机质无坡向差异,各坡向离地面50cm以内的土壤有机质含量在11.2～40.6%,离地面0.5～1m的有机质含量在5.6～17.5%。由于生物资源分布有坡向差异,因此在天然次生林管理时可根据不同的坡向选择相应的开发或保护模式。

Direction effects on plant diversity,earthworm diversity,and soil organic matter of natural secondary forest in dawuling mountains

Investigations were made on plant diversity, earthworm diversity, and soil organic matter in different directions of natural secondary forest in Dawuling Mountains. Four slopes,east-facing slope (EFS),south-facing slope (SFS),west-facing slope (WFS), and north-lacing slope (NFS) of Datianding Hill and Qieding Hill,were sampled. In the Dawuling Mountain, 1)the number of tree was lower on SFS that other directions, the densities of on SFS of Datianding Hill and Qieding Hill being 0 Ind·m^-2 and 0.06 Ind·m^-2, respectively, but there was no difference of tree diversity among directions, Shannon-Weaver index of tree ranging from 0 to 2.24, Margalef index from 0 to 3.15; 2) the number of shrub was not dominant in any directions, but SFS had the lowest shrub diversity, Shannon-Weaver index and Margalef index of SFS of Datianding Hill being 1.52 and 1.70, respectively, those of Qieding Hill being 2.05 and 2.33, respectively; 3) the number of herb on SFS was the highest among those or all directions, the densities of herb on SFS of Datianding Hill and Qieding Hill being 87 Ind·m^-2, and 44 Ind·m^-2,respectively, and SFS also had the highest herb diversity, Shannon-Weaver index and Margalef index of herb on SFS of Datianding Hill being 2.46 and 3.36, respectively; 4) the number of earthworm was low on SFS. the densities of earthworm on SFS of Datianding Hill and Qieding Hill being 7 Ind·m^-2 and 0 Ind·m^-2, respectively, but the earthworm diversities was insignificantly influenced by direction, Shannon-Weaver index of earthworm ranging from 0 to 1.63. Margalef index from 0 to 2.20; and 5) direction had no influence on the content of soil organic matter, and the soil within 50 cm from the surface had 11.2～40.6% of organic matter, that between 50 cm and 100 cm from the surface having 5.6～17.5% of organic matter. Because of direction effects on biological sources, different methods should be used to manage natural secondary forest according to slope-exposure.