不同海拔高度对周公山柳杉人工林植物多样性及土壤养分的影响

【目的】研究海拔高度对周公山柳杉人工林林下植物多样性及土壤养分的影响,对人工林的抚育及合理经营有着重要意义,旨在为人工林近自然改造以及利用山地造林、恢复森林生态提供科学依据。【方法】采用代表性样地法和随机取样法相结合的方法,在800、1 000和1 200 m 3个海拔高度对周公山柳杉人工林林下的物种组成、物种重要值、物种多样性和土壤养分进行了初步研究和对比分析。【结果】1)林下草本层共发现植物33种,属于19科32属;林下灌木层共发现植物49种,隶属于39属26科。2)草本群落Shannon-Wiener多样性指数(H)、Simpson优势度指数(H’)和Pielou均匀度指数(JSW)均随着海拔的升高表现为先升高后降低的趋势,符合"中度膨胀"理论,而草本层物种丰富度指数(D)以及灌木层群落各多样性指数则符合负相关关系理论。3)林下植被0~40 cm深度土壤养分随土层深度增加,全氮、全磷、有效磷、速效钾、有机碳、有机质含量均降低。4)物种多样性指数与有机质、全氮(TN)、全磷(TP)、有效磷(AP)的含量呈显著负相关。【结论】应控制人为干扰的强度,保持合理的林分密度,改善柳杉人工林的物种组成和群落结构,使人工林处于一种天然更新状态。

Effects of different altitude on plant diversity and soil nutrients of Cryptomeria fortunei plantation in Zhougong mountain

【Objective】Studying the influence of altitude on plant diversity and soil nutrients under the forest of C. fortunei plantation in Zhougong mountain is of great significance to the cultivation and rational management of plantation, and the purpose of this paper is to provide scientific basis for the near natural transformation of plantation and the restoration of forest ecology in the use of mountain afforestation.【Method】The species composition, species importance, species diversity and soil nutrients under the forest of C. fortunei plantation in Zhougong mountain were preliminarily studied and compared by means of the combination of representative sample method and stochastic sampling method at 800 m, 1 000 m and 1 200 m three elevations.【Result】1) 33 species of plants were found in the herb layer of undergrowth, belonging to 19 subjects and 32 genera, and 49 species of plants were found in the undergrowth shrub layer, belonging to 39 genera and 26 subjects. 2) The H value, H′ value and JSW value of herb community increased with altitude, which showed the tendency of first rising and decreasing, in line with the theory of "moderate expansion", while the D value of herbaceous layer and the diversity index of shrub layer community were in accordance with the theory of negative correlation relationship. 3) The content of total nitrogen, total phosphorus, effective phosphorus, available potassium, organic carbon and organic matter decreased with the increase of soil nutrient at the depth of 0-40 cm in undergrowth vegetation. 4) The species diversity index was significantly negatively correlated with the content of SOM, TN, TP and AP.【Conclusion】The intensity of human disturbance should be controlled, reasonable forest density should be adopted to improve the species composition and community structure of C. fortunei plantation, so that the plantation is in a natural renewal state.