乔木层植被结构对印支灰叶猴夜宿地选择的影响

Effects of Vegetation Structure of Arbor Layer on Overnight Habitat Selection of Trachypithecus crepusculus

为了评估濒危灵长类印支灰叶猴(Trachypithecus crepusculus)现有分布区的夜宿地质量,并为亚洲疣猴栖息地植被的保护提供具体意见,于2010年1月—2022年12月对云南无量山印支灰叶猴夜宿地选择策略进行研究。通过长期行为监测确定猴群夜宿地位置,利用样方调查法对夜宿地地形、乔木层植被特征和食物资源等因素进行分析。结果表明:(1)印支灰叶猴夜宿地内乔木的胸径[(33.92±6.09)cm]、基径[(38.94±8.36)cm]、树高[(16.10±2.86)m]和有藤乔木株数[(8.32±5.95)株]皆显著高于对照样方,其余生境变量与对照样方无显著差异,说明印支灰叶猴偏好在乔木高大且附生藤本植物丰富的区域夜宿,而地形、冠层覆盖度和食源植物丰富度等因素对印支灰叶猴夜宿地选择无影响。(2)就夜宿地内印支灰叶猴的食源植物而言,红梗楠[Phoebe rufescens,(0.67±1.60)株]、华南蓝果树[Nyssa javanica,(0.66±1.18)株]显著高于非夜宿地,罗浮锥[Castanopsis faberi,0株]、枹丝锥[Castanopsis calathiformis,(0.29±1.17)株]和黄丹木姜子[Litsea elongata,(0.59±3.31)株]显著低于非夜宿地,其余19种食源植物在夜宿地和非夜宿地之间无显著差异,说明食物资源丰富度不是猴群夜宿地选择的限制因素。(3)对调查样方环境因子进行主成分分析,共得到7个环境因子,累计贡献率达到81.23%;非参数检验结果表明,高度因子和藤本因子贡献率高且对猴群夜宿地选择有显著影响;冠层盖度和灌木因子有影响,但主成分贡献率低于10.00%;地形因子、数量因子和乔木外形因子对猴群夜宿地选择无显著影响。总体上,无量山印支灰叶猴在选择夜宿地时因安全需求和便利需求主要受乔木层结构的影响,高大乔木丰富的低海拔森林可能提供更多高质量夜宿地资源,建议在无量山印支灰叶猴保护工作中重点关注低海拔森林栖息地的保护与恢复。

In order to evaluate the quality of the sleeping sites in the current distribution area of the endangered primate In⁃dochinese gray langurs(Trachypithecus crepusculus),and provide recommendations for the conservation of the forest habitats of Asian colobine monkeys,from January 2010 to December 2022,we conducted a study on the sleeping site se⁃lection strategy of Indochinese gray langurs in Wuliangshan,Yunnan Province.We determined the location of the sleeping sites of the monkey group through long-term behavioral monitoring,and analyzed factors such as the topography of the sleeping sites,the characteristics of the vegetation in the tree layer,and the food resources using the sample square sur⁃vey method.The results showed that:(1)The diameter at breast height[(33.92±6.09)cm],basal diameter[(38.94±8.36)cm],tree height[(16.10±2.86)m],and the number of trees with lianas[(8.32±5.95)plants]of trees were signifi⁃cantly higher in the nocturnal roosting area of Indochinese gray langurs than in the control group,but there was no signifi⁃cant difference between other habitat variables and the control sample.These results indicate that the Indochinese gray lan⁃gur preferred to stay at night in the area with tall trees and abundant epiphytic lianas,while topography,canopy cover,and food plant richness had no effect on the choice of night sleeping place of Indochinese gray langur.(2)In terms of the food source plants of the Indochinese gray langur,the abundance of Phoebe rufescens[(0.67±1.60)plants]and Nyssa ja⁃vanica[(0.66±1.18)plants]were significantly higher in the sleeping sites than in the non-sleeping sites,while the abun⁃dance of Castanopsis faberi(0 plants),Castanopsis calathiformis[(0.29±1.17)plants],and Litsea elongata[(0.59±3.31)plants]were significantly lower than those in the non-sleeping sites.The remaining 19 food plants did not differ sig⁃nificantly between the sleeping sites and the non-sleeping sites,suggesting that the abundance of food resources is not a limiting factor in the choice of sleeping sites for the monkeys.(3)A total of seven environmental factors were obtained by principal component analysis,with a cumulative contribution rate of 81.23%.The results of non-parametric test showed that the contribution rates of height factor and vine factor were high and had a significant effect on the selection of the troop’s sleeping sites,the canopy cover and shrub factor had effects,but the contribution rate of the principal component was lower than 10.00%.Terrain factor,quantity factor and tree shape factor had no significant effect on the selection of the troop’s sleeping sites.In general,the selection of night lodging sites for Indochinese gray langurs in Wuliangshan was mainly influenced by the structure of the tree layer due to the safety and convenience needs,and the low-altitude forests with abundant tall trees may provide more high-quality sleeping sites.Therefore,the conservation of Indochinese gray lan⁃gurs in the Wuliangshan should focus on the protection and restoration of low-altitude forest habitat.