小陇山辽东栎次生林的结构特征和物种多样性

Tree Species Diversity and Structure Characteristic of Secondary Forests of Quercus liaotungensis on Xiaolongshan

运用混交度、角尺度、大小比数、林层数等林分空间结构参数,直径分布和物种多样性等非空间结构参数,对小陇山林区辽东栎天然林林分结构特征进行分析研究。结果表明:小陇山林区辽东栎天然林群落的灌木层和草本层物种丰富,多样性高;乔木层物种多样性指数明显低于灌木层和草本层;直径分布特征表现为典型的异龄林直径分布特征;林分天然更新良好,辽东栎实生苗占幼苗总数的46%;林分中林木个体分布角尺度均值为0.541,林木个体水平分布格局属团状分布;群落的树种隔离程度较高,平均混交度高达0.71,群落中77.4%以上的林木处于中度混交以上,处于强度混交的比例也接近于24%;林分中各树种以胸径作为比较指标的大小比数排序为:锐齿栎>辽东栎>漆树>灯台树>华山松>青榨槭>三桠乌药>椴树>秦岭白蜡>梾木;在垂直结构方面,林分的平均林层数为2.45层,林层分化明显。依据辽东栎林分的天然更新和结构特征提出经营建议。

The stand structure characteristics of secondary forests of Quercus liaotungensis on Xiaolongshan was analyzed using spatial structure and non-spatial structure indictors such as mingling, uniform angle index, neighborhood comparison,diameter distribution,layer number and species diversity. The results showed that the species number of shrub layer and the herb layer was abundant and the species diversity was high. The species diversity index of the arbor layer was significantly lower than shrub layer and herb layer. Feature of the stand diameter distribution was typical unevenaged forest character. The stand natural regeneration was good and the number of Q. liaotungensis seedlings accounted for 46% of the total number of seedlings. The stand mean angle index was 0. 541,and the pattern of individual tree horizontal distribution was cluster distribution. The species segregation was high and the average value of mingling was 0. 71. Approximate 77. 4% individual trees was medium mingling and 24% individual tree was intensive mingling in stands. The order of tree species neighborhood comparison compared with breast height diameter was as follow： Quercus aliena var. acuteserrata,Q. liaotungensis,Rhus verniciflus ,Cornus controversa,Pinus armandi,Acer davidii,Lindera obtusiloba, Tilia tuan,Fraxinus paxiana,Crnus macrophylla. The stand average layer number was 2. 45 on vertical structures and the layer was clearly differentiated. Some management advices are proposed according to the regeneration and structure characters of the forests.