六盘山华北落叶松人工林多样性、生产力研究

Species diversity and productivity of Larix principis-rupprechtii plantation woods in Liupan Mountains

根据对宁夏西部六盘山林区人工营造的华北落叶松林典型样地的抽样调查,分析了3种不同类型的华北落叶松林群落中的植物多样性、生产力及其相互关系.结果表明:华北落叶松纯林多样性最小,而落叶松阔叶混交林多样性较大.华北落叶松纯林内的植物种数仅为混交林的53%～60%,植物总数量也只有混交林的16%～38%.落叶松—阔叶混交林总生物量为华北落叶松纯林的152.71%;落叶松—油松—阔叶混交林总生物量为华北落叶松纯林的72.14%.落叶松—油松—阔叶混交林乔木层生物量占其总生物量的比例最大,而华北落叶松纯林最小.3种林型中,草本层生物量所占比例最小.伴生树种是阔叶树,其林地生产力比伴生种有油松等针叶树种的生产力高.在3种不同的落叶松林中,多样性与生产力均表现为正的幂指数函数关系,物种多样性和生产力之间的相关关系达到了显著水平.本文所研究的多样性和生产力之间的关系与许多学者的研究结论所认可的单峰关系不一致,也许只是在单峰关系的左半边,即处于上升阶段.

A sample survey was conducted of artificially planted Larix principis-rupprechtii in the forest district of Liupan Mountains in western Ningxia. At the typical sample plots, species diversity biomass and correlation between them were analyzed. The result indicates that Larix principis-rupprechtii has the minimum species diversity, but deciduous broadleaved forest has a larger species diversity. The amount of foliage pure forests accounts for 53%-60% of total amount of foliage, the total amount of foliage is 16%-38% in the proportion of Larix principis-rupprechtiipure forests. The general biomass of deciduous and broad-leafed mixed forests is 152.71% in the proportion of Larix principis-rupprechtiipure forests, the general biomass of Larix principis-rupprechtii-Pinus tabulaeforrnis-Carr-latifoliate mixed forests is 72.14% and the arbor of Larix principis-rupprechtii-Pinus tabulaeformis-Carr-latifoliate mixed forests has the maximum biomass, whereas Larix principis-rupprechtii has the minimum. Associated species is the main factor of species diversity and productivity. Species diversity and productivity of associated species belonging to hard woods are higher than associated species belonging to Pinus tabulaeforrnis. The relationships between species diversity and productivity always represent plus power index function and the correlativity between the species diversity and productivity has achieved a remarkable level. This article studies the relations between the species diversity and productivity which is inconsistent with the unimodal relationship that many scholars have approved, perhaps only in the left of the unimodal relations, i.e. at the ascent stage.