海南长臂猿不同海拔栖息地的森林群落特征

Forest Community Structure and Diversity Characteristics of Hainan Gibbons’Habitat at Different Altitudes

【目的】通过比较海南长臂猿(Nomascus hainanus)不同海拔栖息地森林群落植物物种组成、多样性及结构特征,探究海南长臂猿现有低海拔次生林栖息地(海拔400~800 m)与高海拔原始林栖息地(海拔800~1200 m)群落特征差异,有助于科学评估现有次生林栖息地对海南长臂猿种群的生态供给情况,为海南长臂猿栖息地保护与恢复奠定基础。【方法】以海南长臂猿现有栖息地为对象,在不同海拔栖息地内共布设122个间距为0.5 km、面积为400 m^(2)的网格固定监测样地,调查样地内木本植物种类及胸径、树高、冠幅等测树因子,比较现有栖息地不同海拔森林群落植物物种组成、多样性及结构特征差异。【结果】高海拔栖息地森林群落植物有56科98属167种,其中小径级植物优势种为药用狗牙花(Tabernaemontana bovina,重要值IV=5.21%),大径级植物(IV=3.94%)、食源(IV=6.28%)与夜宿(IV=9.44%)植物优势种均为白颜树(Gironniera subaequalis);低海拔栖息地森林群落植物有45科75属99种,小径级、大径级、食源与夜宿植物优势种分别为黄牛木(Cratoxylum cochinchinense,IV=6.43%)、南亚松(Pinus latteri,IV=7.57%)、鹅掌柴(Heptapleurum heptaphyllum,IV=14.30%)和枫香树(Liquidambar formosana,IV=22.50%)。高海拔生境森林群落内小径级(t=-4.26,P<0.001)、大径级(t=-6.18,P<0.001)、食源(t=-6.58,P<0.001)和夜宿(t=-8.31,P<0.001)植物的物种丰富度以及夜宿植物的相对多度(t=-4.69,P<0.001)均极显著高于低海拔生境,食源植物相对多度显著高于低海拔生境(t=-2.92,P=0.004)。高海拔、低海拔生境的森林群落乔木冠层可分别划为3、2个亚层,第1亚层优势种分别为黄杞(Engelhardia roxburghiana,IV=5.99%)、南亚松(IV=21.75%);高海拔栖息地森林群落植物冠层厚度(CT:5.95±2.77 m;t=16.82,P<0.001)、树高(H:15.33±4.97 m;t=13.00,P<0.001)、单位面积样地内植物冠幅面积(Crown area:2.65±1.08 m^(2)/m^(2);t=26.69,P<0.001)均极显著高于低海拔生境(CT:3.99±1.70 m;H:12.32±3.67 m;Crown area:0.82±0.61 m^(2)/m^(2)),单位面积样地内胸高断面积(Basal area:0.004±0.001 m^(2)/m^(2);t=4.68,P=0.012)显著高于低海拔生境(Basal area:0.003±0.001 m^(2)/m^(2))。【结论】现阶段低海拔栖息地森林群落的植物物种组成、多样性及结构与高海拔栖息地仍存在较大差异,生境内大量分布的南亚松限制了群落内其他食源树种生长,尚不满足海南长臂猿种群发展的生态需求。未来在海南长臂猿栖息地保护与恢复过程中,需适当考虑择伐低海拔生境内的南亚松、黄牛木等先锋优势树种,抚育群落内鹅掌柴等食源及夜宿植物,补植低地雨林内适合海南长臂猿取食、夜宿的大型食源植物,如榕属(Ficus)植物等,加快现有低海拔生境向低地雨林老龄林的演替进程。

【Objective】By comparing the composition,diversity and structural characteristics of forest communities in habitat at different altitudes,the differences in community characteristics between the existing habitats in the low-altitude secondary forest and the high-altitude primary forest would be explored,which could help to scientifically evaluate the ecological supplication of current low-altitude secondary forest and finally lay a theoretical foundation for the protection and restoration of Hainan gibbons'habitat.【Method】To comparative analyze the composition,diversity and structural characteristics of forest communities in existing habitat at different altitudes,a total of 122 plots with a spacing of 0.5 km and an area of 400 m^(2) were set in the existing habitats at different altitudes,and the tree measurement factors such as diameter,tree height,crown size were investigated,as well as the species name.【Result】A total of 167 plant species of 56 families and 98 genera were found in the high-altitude habitat,with Tabernaemontana bovina(Important Value,IV=5.21%)being dominant in small-diameter plants community,and Gironniera subaequalis being dominant in large-diameter(IV=3.94%),food(IV=6.28%)and nocturnal(IV=9.44%)plants community.While the low-altitude habitat included 99 plant species of 45 families and 75 genera,and the dominant species of small-diameter,large-diameter,food and nocturnal plants community were Cratoxylum cochinchinense(IV=6.43%),Pinus latteri(IV=7.57%),Heptapleurum heptaphyllum(IV=14.30%)and Liquidambar formosana(IV=22.50%)separately.The species richness of small-diameter(t=−4.26,P<0.001),large-diameter(t=−6.18,P<0.001),food(t=−6.58,P<0.001)and nocturnal(t=−8.31,P<0.001)plant species in the forest communities of the high-altitude habitats were all extremely significantly higher than that in the low-altitude ones,as well as the relative abundance of nocturnal plants(t=−4.69,P<0.001).While the relative abundance of food plants was significantly higher(t=−2.92,P=0.004)than in the low-altitude ones.The arbor canopy layer of forest communities could be divided into three sub-layers in the high-altitude habitat with Engelhardia roxburghiana(IV=5.99%)being dominant in the first sub-layer,and two sub-layers in the low-altitude habitat with P.latteri dominating in the first sub-layer(IV=21.75%).The canopy thickness(CT:5.95±2.77 m;t=16.82,P<0.001),crown area(2.65±1.08 m^(2)/m^(2);t=26.69,P<0.001),tree heights(H:15.33±4.97 m;t=13.00,P<0.001)in the high-altitude habitat are extremely significantly higher than those in the low-altitude habitats(CT:3.99±1.70 m;Crown area:0.82±0.61 m^(2)/m^(2);H:12.32±3.67 m),while the basal area at chest height(Basal area:0.004±0.001 m^(2)/m^(2);t=4.68,P=0.012)is significantly higher than that of the low-altitude habitat(Basal area:0.003±0.001 m^(2)/m^(2)).【Conclusion】The plant species composition,diversity and structure of the forest community in the low-altitude habitat still differ greatly from those in the high-altitude habitat currently,and the large number of P.latteri in the habitat would limit the growth of other food tree species within the community,which does not yet meet the ecological needs of the Hainan gibbon population.In the future,during the conservation and restoration process of the Hainan gibbons’habitats,appropriate consideration should be taken to the selection cutting of pioneer species such as P.latteri and C.cochinchinense within the low-altitude habitats,nurturing planting of food and nocturnal plants such as Heptapleurum heptaphyllum within the community,and replanting of large food source plants such as Ficus taxa in the lowland rainforest to accelerate the succession of existing low altitude habitats to OG lowland rainforest.