秦岭大熊猫栖息地主要森林群落类型稳定性分析

Analysis of Stability Evaluation about the Main Forest Communities on the Habitat of Giant Panda in Qinling Mountains

为了揭示秦岭大熊猫栖息地主要森林植物群落稳定性现状,于佛坪和长青国家自然保护区各设置1条样线,每条样线上按海拔每升高100m设置1~4个500m^2(20m×25m)典型样地(共计60个)进行样方调查。在分析调查数据基础上,选取分布最广且具有代表性的16个群落类型林地,并利用模糊数学隶属函数对其优势种更新、林地质量、群落物种多样性、群落复杂性、土壤肥力、保护程度6个方面对各群落类型林地的植物群落稳定性进行综合分析评价。结果表明:(1)栓皮栎群落林下的幼苗和幼树数量相对最多,隶属函数最大,其更新能力较强;华山松群落林下的幼苗和幼树数量为零,其更新能力最差。(2)华山松和油松混交林群落林地的立木蓄积量、平均高度、枯落物厚度等3个隶属函数平均值最高,其林地质量相对最好;油松和锐齿槲栎混交林则相反,林地质量相对较差。(3)群落林地土壤肥力6项指标分析显示,太白红杉林隶属函数值最大,土壤肥力相对较高,而板栗林、亮叶桦林隶属函数较小,土壤肥力相对最低。(4)群落林地物种多样性分析显示,铁杉林隶属函数最大,物种多样性表现更为突出,太白红杉林隶属函数值最小,其物种多样性表现相对最差。(5)铁杉林林地群落的复杂性3个方面隶属函数相对最高,复杂性最高,太白红杉则相对最低。(6)太白红杉、巴山冷杉因分布在保护区核心区域,群落林地的保护程度最高,而毛栗林、亮叶桦因分布于保护区边缘的实验区,保护程度最差。(7)综合对比6个指标隶属函数发现,16个群落林地的稳定性由大到小顺序为:铁杉林>短柄枹栎林>太白杨林>华山松林>锐齿槲栎林>巴山冷杉林>白桦林=红桦林>油松+华山松=牛皮桦林>油松+锐齿槲栎混交林>油松林>太白红杉林>栓皮栎林>板栗林>亮叶桦林。

In order to revealed the plant community stability on the habitat of giant panda in Qinling Mountains we set two line transects between the altitude of 900-3 071 min the field,and the standard plots（20m×25m）were investigated on transects in Foping and Changqing Nature Reserves.Based on analysis of survey data,community stability of 16 representatives and typical community types were evaluated by subordinate function of fuzzy mathematics.The evaluation index included the regeneration of dominant species,stand qualities,diversity,community complexity,soil fertility and protective degree.The results showed that：（1）according to the analysis of regeneration ability of dominant species in different com-munity tree layer,the quantity of undergrowth seedlings and young trees of Quercus variabilis were the highest and the subordinate function value was largest,showing the regeneration ability was best.However,none of seedlings and young trees grew under the Pinusarmandiiforest and the subordinate function value was lowest,showing the regeneration ability was worst.（2）According to the analysis of quality of forest land in different communities,the average subordinate function value of growing stock volume and the quality of forest land in mixed forest of Pinusarmandiiand Pinus tabulaeformis were best.However,the average height and litter depth were the lowest in mixed forest of Pinus tabulaeformis and Quercus aliena var.acuteserrata,the quality of forest land was worse.（3）According to the analysis of forest soil fertility,the membership function of Larix chinensis forest was highest and soil fertility was higher,whereas the subordinate function value of Castanea mollissima and Betula luminifera were lower and the soil fertility was lower too.（4）According to the species diversity of forest land in different communities,the subordinate function value of Tsuga chinensis was the highest which showed a outstanding species diversity,and the subordinate function value of Larix chinensis was lower,showing a lower species diversity.（5）According to the complexity of forest land in different communities,the subordinate function value of three aspects of complexity in Tsuga chinensis was relatively higher which showed high community complexity,whereas the subordinate function value of Larix chinensis was lower and the community complexity was lower too.（6）According to the protective degree of forest land in different communities,the protective degree of Larix chinensis and Abies fargesii were high for they were distributed in core region of protected area,while the protective degree of Castanea mollissimaand Betula luminifera were low because of the marginal division of protected area.（7）The subordinate function value showed that the community stability can be arranged as an order of Tsuga chinensis〉Quercus glanduli fera var. brevipetiolata〉 Populus purdomi〉 Pinus armandii 〉Quercus aliena var. acuteserrata〉Abies far gesii〉Betula plat yph ylla = Betula albo-sinensis〉 Pinus tabulae formii＋Pinus armandii = Betula albo-sinensis vat. septentrionalis〉 Pinus tabulae formis ＋Quercus aliena vat. acuteserrata 〉 Pinus tabulae formis 〉 Larix chinensis 〉Quercus variabilis 〉Castanea mollissima 〉 Betula luminifera from high to low.