油松和樟子松人工林不同坡位土壤养分特征及其与生长性状的关系--以辽东地区为例

Characteristics of Soil Nutrients and Relations with Stand Growth of Pinus tabulaeformis and Pinus sylvestnis var. mongolica Plantations under Different Slopes in Low Mountains and Hill District of Eastern Liaoning Province

为研究辽东低山丘陵区油松(Pinus tabulaeformis)和樟子松(Pinus sylvestnis var.mongolica)人工林在不同坡位的土壤养分分布特征及其与林木生长性状间的关系,本研究对桓仁、清原和本溪3个地点共计18块样地的油松和樟子松林分进行调查,按照不同坡位(坡上、坡中、坡下),分上、下两层(0~15cm和15~30cm)采集土壤样本,并在每层钻取周边4个点,混合成1个样本,带回实验室测定土壤有机碳、全氮、速效氮、全磷和速效磷。结果表明:两树种林地土壤养分特征均表现为,坡下>坡上>坡中,上层>下层,其中土壤全磷含量在不同坡位和土层呈现出明显差异;两树种坡下的各土壤养分元素间相关系数高于坡中和坡上,其中,油松林地土壤养分间相关系数超过0.880,樟子松林地土壤养分间相关系数超过0.910,均达到极显著水平;两树种土壤养分与林木生长性状间相关性结果,除油松林地坡上和坡中的土壤有机碳与冠幅呈极显著的正相关,坡上和坡中的土壤全氮和全磷与冠幅呈显著的负相关,坡中的土壤全磷与树高呈显著的负相关,以及樟子松林地坡上和坡中土壤有机碳与冠幅呈极显著的负相关外,两者林地坡上和坡中的土壤养分与各生长性状间的关系不紧密,而坡下的土壤养分与林木生长性状的相关性高于坡中和坡上,且大部分达到显著水平。综合来看,两种造林树种坡下表层土壤养分能显著影响林木生长状况,在林分经营过程中,可据此进行针对性管护。

Characteristics of spatial distribution of soil nutrients of Pinus sylvestnis var.mongolica(P.mongolica)and Pinus tabulaeformis(P.tabulaeformis)plantations in low mountains and hill district of eastern Liaoning province and their relations with growth traits under different slope positions were studied.Our research aimed to provide theoretical basis for soil nutrients and forest management of P.tabulaeformis and P.mongolica tree species.The experiments were conducted in Huanren,Qingyuan and Benxi spots,18plots in total.Investigations were made on the soil samples collected from different slope positions(upper,middle and lower slope),top and underlying layers(0-15cm and15-30cm).Four subsamples were collected from in each layer and then were mixed to1sample.Soil organic C,total N,total P,available N and available P were measured in the laboratory.The result indicated that the order of soil nutrient content was:lower slope>upper slope>middle slope,top>underlying layer.There was obvious difference in total P content between slope positions and soil depth.The correlations of soil nutrient contents in lower slope were higher than those of middle and upper slope.In P.tabulaeformis plantation,the correlation coefficients of nutrients were above0.880,and in3.mongolica plantation,those were above0.910,both reaching to significant levels.In P.tabulaeformis plantation,for the relations of soil nutrient contents and growth traits in upper and middle slope,soil organic C was significantly positively correlated with canopy,and total N and total P were significantly negatively correlated with canopy.For the relations of soil nutrient contents and growth traits in middle slope,total P was significantly negatively correlated with tree height.In P.mongolica plantation,the relations of soil nutrient contents and growth traits in upper and middle slope,soil organic C was significantly negatively correlated with canopy.The relationships between other soil nutrients and growth traits under upper and middle slope were insignificant.The relations of soil nutrient contents and growth traits in lower slope were higher than those of middle and upper slope,most of soil nutrient and growth indicators reaching to significant level.Overall,the soil nutrient in surface soil under lower slope nutrient can significantly affect the growth traits of two tree species,and during the forest management processes,such forest management and protection can be done based on our research results.