古田山国家级自然保护区甜槠林优势种群生态位

采用样方法进行不同资源位群落调查,利用生态位宽度、生态位相似性比例和生态位重叠公式测试了古田山国家自然保护区甜槠林14个优势种群甜槠(Castanopsis eyrei)、木荷(Schima superba)、马银花(Rhododendron ovatum)、檵木(Loropetalum chinensis)、麂角杜鹃(Rhododendron latoucheae)、虎皮楠(Daphniphyllum macropodum)、马尾松(Pinus massoniana)、青冈(Cyclobalanopsis glauca)、乌饭树(Vaccinium bracteatum)、石栎(Lithocarpus glaber)、赤楠(Syzygium buxifolium)、石楠(Photinia serrulata)、栲树(Castanopsis fargesii)、钩栗(Castanopsis tibetana)]的生态位.结果表明:甜槠和木荷的生态位宽度较大,其Bi、Ba分别为0.8703、0.8528和0.8446、0.7824;而石楠、栲树和钩栗的生态位宽度较小,其Bi、Ba分别为0.2956、0.1359,0.2953、0.1356和0.2684、0.1064.生态位宽度较大的物种之间的生态相似性比例较大,如甜槠与木荷、甜槠与马银花、木荷与马银花的生态相似性比例分别为0.7630、0.7252和0.6452;对生境需求有较大相似性的生态位宽度不同的物种其生态位相似比例也会较高,如木荷与马尾松生态位相似比为0.6866.生态位宽度较大的树种间生态位重叠较大,如甜槠、木荷、马银花等.甜槠林中生态位重叠值大于0.1的有39对,仅占21.4%,生态位重叠值不大,表明甜槠林中因利用相同的资源位而产生的种间竞争并不激烈,是一个稳定的森林群落.

he niche of dominant species populations in Castanopsis eyrei forest in Gutian Mountain National Nature Reserve

A field plot sampling method was employed to investigate community niche of Castanopsis eyrei forest in Gutian Mountain National Nature Reserve. Parameters of niche breadth, niche similarity and niche overlap were calculated to show community characteristics of 14 dominant species, including Castanopsis eyrei, Schima superba, Cyclobalanopsis glauca, Loropetalum chinensis, Daphniphyllum macropodum, Rhododendron ovatum, Lithocarpus glaber, Rhododendron latoucheae, Castanopsis fargesii, Photinia serrulata, Castanopsis tibetana, Pinus massoniana, Syzygium buxifolium and Vaccinium bracteatum. The results showed that niche breadths of Castanopsis eyrei and Schima superba were larger than other species, with Levins (Bi) and Hurlbert's (Ba) values being 0.8703 and 0.8528, and 0.8446 and 0.7824, respectively. Smaller niche breadths were found for Photinia serrulata, Castanopsis fargesii and Castanopsis tibetana species, with Bi and Ba values being 0.2956 and 0.1359, 0.2953 and 0.1356, and 0.2684 and 0.1064, respectively. The niche similarity between populations increased with niche breadth, as shown between Castanopsis eyrei and Schima superba, between Castanopsis eyrei and Rhododendron ovatum, or between Schima superba and Rhododendron ovatum, similarity values being 0.7630, 0.7252 and 0.6452, respectively. Despite of difference in niche breadth, in addition, large niche similarity existed between Schima superba and Lithocarpus glaber (0.6866) due to their similar habitat requirements. Niche overlap degree between populations increased with niche breadth, which was shown in Castanopsis eyrei, Schima superba and Rhododendron ovatum, etc. Only 39 sets of Castanopsis eyrei forest had niche overlap values greater than 0.1, accounting for 21.4% of the total. Therefore, small niche overlap degree found in this study suggests less fierce interspecies competition in the forest, representing a stable community of the Castanopsis eyrei forest of Gutian Mountain.