| 沙地樟子松散生单木的天然更新幼苗空间分布模型 |
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| 引用本文： | 王锋,卢琦.沙地樟子松散生单木的天然更新幼苗空间分布模型[J].林业科学,2019(8):1-8. |
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| 作者姓名： | 王锋 卢琦 |
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| 作者单位： | 中国林业科学研究院荒漠化研究所 |
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| 基金项目： | 中央级公益性科研院所基本科研业务费专项资金青年人才项目(CAFYBB2017QC007);国家自然科学基金项目(31100518,31570710);国家重点研发计划(2016YFC0500801) |
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| 摘 要： | 【目的】构建具有清晰空间结构的樟子松天然更新幼苗空间分布模型,阐明沙地樟子松散生单木的天然更新幼苗空间分布特征,为重要固沙乔木樟子松天然更新和扩张方向预测提供参考依据。【方法】以呼伦贝尔沙地天然樟子松散生单木为研究对象,利用VonMises分布和韦伯分布构建具有清晰空间结构的樟子松散生单木天然更新幼苗分布模型。基于10株散生樟子松母树及其1374株更新幼苗观测数据,采用由最小二乘法估计模型参数,并应用模型随机模拟樟子松散生单木天然更新幼苗的空间分布状况。【结果】1)樟子松散生单木的天然更新幼苗分布符合Janzen-Connell假说,但更新幼苗分布具有明显的方向性,主要分布在方位角(正北为0°,顺时针旋转)为0°~127°和216°~360°2个区间中,更新幼苗与母树的距离集中在0.37~10.95m,树龄较高的幼苗主要分布在距离母树较远的地方;樟子松散生单木的天然更新幼苗空间分布模型由更新幼苗数量模型、方向分布模型和距离分布模型构成,基于模型发现,樟子松天然更新幼苗的平均扩散方向为北偏东16°,平均扩散距离为5.37m;应用樟子松散生单木天然更新幼苗模型模拟地径为70cm的樟子松母树更新幼苗群体空间格局,生成的樟子松单木天然更新幼苗共97株,模拟的更新幼苗空间分布与观测一致。【结论】樟子松散生单木天然更新幼苗在扩散距离上符合Janzen-Connell假说,但分布具有方向性,绝大部分幼苗分布在母树北面。樟子松幼苗存活要求较低的太阳辐射微环境,没有遮荫的环境不利于天然更新。樟子松散生单木的天然更新幼苗空间分布模型可清晰描述单株樟子松周围更新幼苗的空间格局。
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| 关 键 词： | 森林动态 空间格局 空间直观模型 Janzen-Connell假说 天然更新 |
A Spatial-Explicit Seedling Recruitment Model for Scattered Individual Trees of Pinus sylvestris var. mongolica |
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| Wang Feng,Lu Qi.A Spatial-Explicit Seedling Recruitment Model for Scattered Individual Trees of Pinus sylvestris var. mongolica[J].Scientia Silvae Sinicae,2019(8):1-8. |
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| Authors: | Wang Feng Lu Qi |
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| Institution: | (Institute of Desertification Studies,CAF,Beijing 100091) |
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| Abstract: | 【Objective】We present a spatial-explicit model of seedlings establishment for scattered individual trees of Pinus sylvestris var.mongolica,which describes the spatial pattern of seedling recruitments.This study will provide a basis for prediction of expanding trend and natural regeneration of Pinus sylvestris var.Mongolica.【Method】A new spatial-explicit seedling recruitment model was developed based on the Von Mises distribution and Weibull distribution.The proposed model was calibrated by the least square method based on the measurement dataset of 1 374 seedlings from 10 scattered individual trees of Pinus sylvestris var.mongolica located at Hulun Buir sandy land in Northeast China.The proposed model simulated the spatial pattern of seedlings from an isolated Mongolian Scots pine with the base diameter of 70 cm.【Result】1)The spatial pattern of natural regeneration for scattered individual trees of Pinus sylvestris var.mongolica followed the Janzen-Connell hypothesis but had the specific direction.The azimuth of seedlings had two zones of 0°-127°and 216°-360°,and the distance of seedlings to the parent tree was 0.37-10.95 m;2)The spatial-explicit seedling recruitment model consists of seedling number modules,azimuth modules and distance modules.Derived from the model,we found the mean directions of seedlings dispersal were 16°north by east,and the mean distances of seedlings dispersal were 5.37 m;3)The simulated spatial pattern of seedling recruitment agreed well with the observed ones.【Conclusion】The distances between seedlings and parent tree followed the Janzen-Connell’s hypothesis,but their azimuth had the specific direction.The success of seedling establishment requires low radiation. |
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| Keywords: | forest dynamics spatial pattern spatial-explicit model Janzen-Connell hypothesis natural regeneration |
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