冀北沙漠化土地人工防风固沙林林下植被物种多样性研究

Plant species diversity of windbreak in desertification land of northern Hebei province

采用典型样地调查法,在冀北沙漠化土地人工防风固沙林中选取林龄20年以上和10年以下的落叶松(Larix principis-rupprechtii)、樟子松(Pinus sylvestris var.mongolica)、北京杨(Populus beijingensis)6种不同林分,利用α多样性指数对其林下草本层物种多样性进行分析。结果表明:相同树种不同林龄的林分是林龄越大,多样性水平越高;相近林龄不同树种的林分是:落叶松林下草本物种多样性水平最高,樟子松次之,北京杨最低。6种林分林下草本物种多样性水平排序为:林龄20年以上落叶松>林龄20年以上樟子松>林龄10年以下落叶松>林龄20年以上北京杨>林龄10年以下樟子松>林龄10年以下北京杨。

Using sample plot investigation method, forest ages were more than 20 years and less than 10 years were selected in six different plantations forests of Larix principis-rupprechtii, Pinus sylvestnis var. mongolica and Populus beijingensis in desertification land of northern Hebei Province, then using 〉diversity index analyzed the species diversity of herb layer. The results indicated that the older forest age had the higher diversity in forests of same tree spe- cies. Larix principis-rupprechtii forest had the highest herbaceous species diversity, followed by Pinus sylvestnis var. mongolica, and Populus beijingensis had the lowest species diversity in forests with similar forest age. Six kinds of forest stand＇s herbaceous species diversity order： forest age more than 20 years of Larix principis-rupprechtii〉forest age more than 20 years of Pinus sylvestnis var. mongolica 〉 forest age less than 10 years of Larix principis-rupprechtii forest age more than 20 years of Populus beijingensis〉 forest age less than 10 years of Pi- nus sylvestnis var. mongolica 〉 forest age less than 10 years of Populus beijingensis.