祁连山不同海拔青海云杉天然更新空间格局变化  

Changes in the spatial pattern of natural regeneration of Picea crassifolia at different elevations in the Qilian Mountains

作　　者：刘济萌 刘贤德[1,2] 马瑞 赵维俊[2] 敬文茂 许尔文 杨逍虎 LIU Jimeng;LIU Xiande;MA Rui;ZHAO Weijun;JING Wenmao;XU Erwen;YANG Xiaohu(College of Forestry,Gansu Agriculture University,Lanzhou 730070,China;Water Sources Conservation Forests Research Institute of Qilianshan National Nature Reserve(Gansu Qilianshan Forest Eco-system of the State Research Station),Zhangye 734000,China)

机构地区：[1]甘肃农业大学林学院,兰州730070 [2]甘肃省祁连山水源涵养林研究院(甘肃祁连山森林生态系统国家定位观测研究站),张掖734000

出　　处：《生态学报》2025年第5期2337-2345,共9页Acta Ecologica Sinica

基　　金：国家自然科学基金区域创新发展联合基金项目(U21A20468);甘肃省自然科学基金项目(24JRRG034);甘肃省高校产业支撑计划项目(2023CYZC⁃45);张掖市市级科技计划项目(ZY2022KY03)。

摘　　要：青海云杉(Picea crassifolia)作为祁连山森林生态的建群种,在维系林区生物多样性、保持水土等方面起着非常重要的生态作用,探究其天然更新的空间格局时空动态特征对种群更新具有重要意义。在海拔2800 m、3000 m、3300 m的青海云杉林中设置固定样地,并于2017年、2022年记录样地所有胸径<50 mm的青海云杉胸径、冠幅和坐标等信息。通过Ripley′s K函数、单变量标记点格局探究青海云杉胸径对空间分布特征的影响,再使用Moran′s I统计量和Zα统计量分析青海云杉胸径空间关联性特征,使用LISA聚类方法识别每个青海云杉的胸径在空间中的相互作用关系。结果表明:(1)更新苗空间格局年际间变化整体呈现为聚集程度增加的趋势,2800 m样地聚集程度变化最大,3000 m与3300 m样地聚集程度变化较小,2017年2800 m和3000 m样地存在随着空间尺度的增加聚集分布和随机分布交替出现的现象,2022年这种现象基本消失。(2)基于胸径的单变量标记点格局能够敏锐地捕捉到胸径对空间格局的影响,但随着聚集程度的增加,这种影响逐渐消失。(3)2800 m、3300 m样地的胸径空间关联性年际变化呈现为空间正自相关加强的趋势,在2022年均表现出显著的空间正自相关,3000 m样地呈现为空间负自相关加强的趋势,在2022年表现出不显著的空间负自相关。(4)2800 m样地更新苗胸径集聚模式变化较大,高高集聚与低低集聚的数量显著增加,3000 m样地更新苗胸径集聚模式变化不大,基本无显著空间关联性的植株,3300 m样地更新苗胸径集聚模式变化较大,高高集聚的数量显著增加。考虑到聚集程度的增加带来的影响是复杂的,既包括消极的影响也包括积极的影响。建议在今后的经营管理中可以对呈现低低集聚的青海云杉幼苗进行适当剪除,减小种群的竞争压力从而提高幼苗存活率。Picea crassifolia,as a constructive species of forest ecology in Qilian Mountains,plays a very important ecological role in maintaining forest biodiversity and soil and water conservation.It is of great significance to explore the temporal and spatial dynamic characteristics of its natural regeneration spatial pattern for population regeneration.Fixed plots were established in P.crassifolia forests at altitudes of 2800 m,3000 m,and 3300 m,recoring the diameter at breast height(DBH),crown width,and coordinates of all P.crassifolia trees with DBH<50mm were recorded in 2017 and 2022.The influence of DBH of P.crassifolia on spatial distribution characteristics was explored by K function and univariate marker point pattern.Moran′s I statistics and Zαstatistics were used to analyze the spatial correlation characteristics of DBH of P.crassifolia.LISA clustering method was used to identify the spatial interaction relationship of DBH of each P.crassifolia.The results show that:(1)The interannual variation of the spatial pattern of new seedlings generally demonstrated an increasing trend in aggregation.The aggregation degree of 2800 m plot changed the most,while the aggregation degree of 3000 m and 3300 m plot changed little.In 2017,there was an alternate phenomenon of aggregation distribution and random distribution with the increase of spatial scale in 2800 m and 3000 m plot.By 2022,this phenomenon has largely disappeared.(2)The univariate marker pattern based on DBH could keenly capture the effect of DBH on spatial pattern,but this effect gradually disappeared with the increase of aggregation degree.(3)The interannual variation of the spatial correlation of DBH in the 2800 m and 3300 m plots showed a strengthening trend of positive spatial autocorrelation,showing a significant positive spatial autocorrelation in 2022,and the 3000 m plot showed a strengthening trend of negative spatial autocorrelation,showing an insignificant negative spatial autocorrelation in 2022.(4)The DBH agglomeration pattern among new seedlings

关 键 词：青海云杉 天然更新 空间分布 空间集聚 

分 类 号：G63[文化科学—教育学]