Analysis of solute preferential transport in a dark coniferous forest ecosystem of Gongga Mountain,Sichuan Province,southwestern China

We selected a dark coniferous forest ecosystem of Gongga Mountain in the upper reaches of the Yangtze River as our research area to study the preferential flow and solute preferential transport by adding the tracers KNO3 and KBr to the self-made soil column equipment in different ways to examine density and volume changes of inflows and outflows of a mass input （impulse input） and a stable, well-distributed input （step input））. The results showed that this dark coniferous forest ecosystem of Gongga Mountain is a typical area of preferential flow and solute preferential transport, a process that can be classified into five parts. A great amount of solute was transported at high speed as the result of preferential flow in the soil and caused the density of the solute in both deep water and in groundwater to rise rapidly, which definitely increased pollution in the deep soil layer.

Tree structure and diversity shape the biomass of primary temperate mountain forests

Primary forests are spatially diverse terrestrial ecosystems with unique characteristics,being naturally regenerative and heterogeneous,which supports the stability of their carbon storage through the accumulation of live and dead biomass.Yet,little is known about the interactions between biomass stocks,tree genus diversity and structure across a temperate montane primary forest.Here,we investigated the relationship between tree structure(variability in basal area and tree size),genus-level diversity(abundance,tree diversity)and biomass stocks in temperate primary mountain forests across Central and Eastern Europe.We used inventory data from726 permanent sample plots from mixed beech and spruce across the Carpathian Mountains.We used nonlinear regression to analyse the spatial variability in forest biomass,structure,and genus-level diversity and how they interact with plot-level tree age,disturbances,temperature and altitude.We found that the combined effects of genus and structural indices were important for addressing the variability in biomass across different spatial scales.Local processes in disturbance regimes and uneven tree age support forest hete rogeneity and the accumulation of live and dead biomass through the natural regeneration,growth and decay of the forest ecosystem.Structural complexities in basal area index,supporte d by genus-level abundance,positively influence total biomass stocks,which was modulated by tree age and disturbances.Spruce forests showed higher tree density and basal area than mixed beech forests,though mixed beech still contributes significantly to biomass across landscapes.Forest heterogeneity was strongly influenced by complexities in forest composition(tree genus diversity,structure).We addressed the importance of primary forests as stable carbon stores,achieved through structure and diversity.Safeguarding such ecosystems is critical for ensuring the stability of the primary forest,carbon store and biodiversity into the future.

Soil ecosystem changes by vegetation on old-field sites over five decades in the Brazilian Atlantic forest

Vegetation types alter soil ecosystems by changing soil fauna community activities and soil physi-cal-chemical properties.However,it is unclear how tree species(natural forest,native and exotic tree plantations)promote changes in the soil ecosystem,and if these changes alter functional groups of soil fauna and ecosystem services.To determine the effects of five decades of old-field veg-etation on soil ecosystems in the Brazilian Atlantic Forest,field sampling of three ecosystems(exotic tree species Pinus elliottii Engelm.plantation,endangered tree species Arau-caria angustifolia(Bertol.)Kuntze plantation,and a natural ecosystem)were carried out,as well using bait-lamina tests and bioassays with collembolans,earthworms and seeds of Lactuca sativa L.Field sampling evaluated the soil fauna community and soil physical-chemical properties.The bait-lamina test in situ was carried out for 14-days to deter-mine fauna feeding activity,and the bioassays evaluated the reproduction of Folsomia candida,the avoidance of Eisenia andrei,and germination of L.sativa in the soil from each ecosystem.The results are:(1)vegetation type altered the soil fauna community composition;(2)soil fauna feeding was reduced in the plantations compared to the natural eco-system;(3)a physical barrier was created by recalcitrant litter that compromised fauna community structure and seed bank germination in situ;and,(4)changes in soil physical-chemical properties promoted decomposers.

Tree diversity effects on forest productivity increase through time because of spatial partitioning

Background: Experimental manipulations of tree diversity have often found overyielding in mixed-species plantations. While most experiments are still in the early stages of stand development, the impacts of tree diversity are expected to accumulate over time. Here, I present findings from a 31-year-old tree diversity experiment(as of2018) in Japan.Results: I find that the net diversity effect on stand biomass increased linearly through time. The species mixture achieved 64% greater biomass than the average monoculture biomass 31 years after planting. The complementarity effect was positive and increased exponentially with time. The selection effect was negative and decreased exponentially with time. In the early stages(≤ 3 years), the positive complementarity effect was explained by enhanced growths of early-and mid-successional species in the mixture. Later on(≥ 15 years), it was explained by their increased survival rates owing to vertical spatial partitioning — i.e. alleviation of self-thinning via canopy stratification. The negative selection effect resulted from suppressed growths of late-successional species in the bottom layer.Conclusions: The experiment provides pioneering evidence that the positive impacts of diversity-driven spatial partitioning on forest biomass can accumulate over multiple decades. The results indicate that forest biomass production and carbon sequestration can be enhanced by multispecies afforestation strategies.

Dynamics of tree species ecological groups in logged and unlogged tropical forests in the Venezuelan western plains

The study of tree mortality and recruitment contributes to the understanding of forest dynamics and, at the same time, supplies a baseline to evaluate the impact of human activities. The study site is a moist semi-deciduous forest located in the Caparo Forest Reserve, Venezuela. Tree data were obtained from permanent plots established in unlogged and logged stands. Successive measurements were taken during a 15 yr period. Tree species mortality and recruitment was analyzed for individuals with diameter at breast height （d）〉-- 10 cm. The species were classified according to their shade tolerance （low or intolerant, intermediate and high or tolerant） and the maximum height （hmax） （small〈15 m, medium： 15-30 m and large 〉30 m）. Palms were considered as a separate group. In the unlogged stands 307 and 274 trees ha-1 were found at the beginning and final time of the monitoring period, respectively. These trees were classified into 55 and 48 species, respectively. Among them predominate species from the shade intermediate tolerant and large size group and palms. Similarly, in the logged forest 155 and 207 trees ha^-1 were found, whereas 59 and 60 tree species were recorded. Only four species were found with 〉10 individuals had, the majority of these species belong to the functional group of shade intolerant medium size species, which may be partly explained by forest recovering after selective logging. In the unlogged stands the mean annual rate of tree mortality is 2.61% and the highest values corresponded to shade intermediate tolerant and intolerant small size species. Tree density was not significantly correlated to tree mortality in both forest conditions （logged and unlogged）. The recruitment rate in the unlogged forest was 1.33%, with the lowest values obtained for the same groups with highest mortality; whereas in the logged stands reached 2.58%, with the highest value for the shade tolerant small size species, followed by shade intermediate tolerant large size species. A significant difference was found between forest conditions for tree recruitment rates （H=0.0649）. In contrast, the correlation between tree mortality and recruitment was higher for logged （r=0.5988） than unlogged stands （r=0.4904） but not significant.

菌根真菌影响森林生态系统碳循环研究进展

森林生态系统在全球碳(C)储量中占据极为重要的地位。菌根真菌广泛存在于森林生态系统中,在森林生态系统C循环过程中发挥重要的作用。阐述了不同菌根类型真菌在森林生态系统C循环过程中的功能,对比了温带/北方森林与热带/亚热带森林中菌根真菌介导的C循环研究方面新近取得的研究结果。发现温带和北方森林的外生菌根(EcM)植物对地上生物量C的贡献相对较小,然而是地下C储量的主要贡献者;以丛枝菌根(AM)共生为主的热带/亚热带森林地表生物量占比较高,表明AM植被对热带/亚热带森林地上生物量C的贡献相对较大。我们还就全球变化背景下,菌根真菌及其介导的森林生态系统C汇功能,以及不同菌根类型树种影响C循环的机制等进行了总结。菌根真菌通过影响凋落物分解、土壤有机质形成及地下根系生物量,进而影响整个森林生态系统的C循环功能。菌根介导的森林C循环过程很大程度上取决于(优势)树木的菌根类型和森林土壤中菌根真菌的群落结构。最后指出了当前研究存在的主要问题以及未来研究展望。本文旨在明确菌根真菌在森林生态系统C循环转化过程中的重要生态功能,有助于准确地评估森林生态系统C汇现状,为应对全球变化等提供重要的依据。

黔中地区马尾松-甜槠针阔混交林群落结构特征与林木空间分布格局及其关联性

为探究黔中地区天然次生马尾松针阔混交林群落结构及其空间分布格局特征,选取典型的马尾松-甜槠针阔混交林和马尾松纯林为调查对象,采用成对相关函数分析环境异质性对主要树种空间分布的影响、主要树种及径级空间格局和空间关联性研究。调查共记录91种植物,其中马尾松-甜槠针阔混交林和马尾松纯林分别为42种和68种。2个森林群落中乔木总径级整体均呈倒“J”形结构,结构稳定,自然更新良好。结果表明,生境异质性对2种群落类型在小距离上空间分布格局的影响作用明显。2块样地幼树、中树及总体分布格局相似,均为点距离在0~10 m内呈聚集分布、在10~25 m内呈随机分布,而大树在整个观察尺度内均为随机分布。马尾松纯林中马尾松-甜槠、甜槠-槲栎的空间关联性均以不相关为主,马尾松-槲栎以负相关为主;而马尾松-甜槠针阔混交林中马尾松与甜槠在10~20 m以负相关为主。2种群落类型不同径级的空间关联性总体为不相关。黔中山地天然次生马尾松-甜槠针阔混交林、马尾松纯林群落结构存在差异,环境异质性、径级结构和空间尺度对两者空间分布格局及其关联性影响明显。

气候因子对云冷杉针叶混交林主要针叶树种径向生长的贡献率分析

【目的】为分析气候变化对针叶树种径向生长的影响,揭示针叶混交林对气候变化的响应规律,在全球气候变暖的背景下,对森林生态系统的适应性经营提供理论支撑。【方法】以金沟岭林场云冷杉针叶混交林中的3个针叶树种为研究对象,建立3个针叶树种的树轮宽度标准化年表,分析3个树种的树轮宽度与气候因子之间的相关关系,明确该地区显著限制其径向生长的气候因子,并用层次分割法量化气候因子对各树种树轮宽度变化的贡献率。【结果】在95%的置信区间下,与气候因子相关分析显示:红松和臭冷杉的径向生长同时受气温和降水的影响,与生长季初期气温正相关;鱼鳞云杉的树轮宽度主要受气温影响,与秋冬季节气温负相关,与降水量的整体相关性较低。3个树种均受到上一年气候因子的影响,有一定的“滞后效应”。滑动相关分析表明,本研究3个主要针叶树种与气候因子的响应关系存在差异,主要表现为负相关性呈增强趋势。3月平均气温对红松的贡献率最高,为34.56%,4月最低气温对臭冷杉的贡献率最高,为22.29%,对鱼鳞云杉的贡献率为60.89%。【结论】层次分割分析法能够有效量化气候因子对各树种树轮生长的贡献率,分析结果可为制定该地区应对未来气候变化的经营管理措施提供理论参考。

基于LiDAR数据与光谱影像融合的单木提取方法

针对现有的机载数据单木分割方法对林型的普适度不高,尤其在高郁闭度阔叶林地带提取精度偏低的问题,选用海南省海口市热带阔叶林地带的光谱影像和LiDAR数据,先采用基于距离阈值的单木分割方法,利用高分光谱影像分割得到的树冠边缘,对初始探测树顶点进行位置约束。获得单木顶点的精确定位后,采用基于种子点的单木分割方法分割,完成了阔叶林的单木提取。结果显示,与已有的基于单木间相对间距单木分割方法相比,本研究通过选取最佳分割尺度结合光谱影像进行精确定位,改善了原有单一尺度分割方法导致的过分割现象,将单木识别精确率由0.67提升至0.92。该方法在使用遥感对森林单木进行分割工作中,可以更好地识别单木,对不同林型适用度较高,可以为后续的单木信息提取工作提供数据基础。

邻体竞争对城市森林微景观中针叶树视觉形态性状的影响

树木视觉形态性状是城市绿地微景观美学质量的重要影响因素之一,树木视觉形态性状的变化与其周围邻体木的竞争作用息息相关,但邻体竞争对树木视觉性状的作用机制尚不明确。研究于2022年8—10月对北京市城市公园中常见的针叶树种白皮松、侧柏、油松、圆柏展开调查,从树冠形态、干冠协调、树干形态3个方面构建了9个树木视觉形态性状指标,采用3个不同的竞争指标分析邻体竞争对针叶树种视觉形态性状的影响。结果表明,针叶树的树冠形态对邻体竞争的响应比较敏感,竞争中的白皮松、侧柏、油松、圆柏偏冠指数与孤立木相比分别提高了16.95%、28.95%、22.76%、17.67%;树冠缺失率分别提高了3.92%、6.09%、4.87%、4.95%。与孤立木相比,部分针叶树种高径比、分枝角变异度在多侧竞争环境中显著提高,而树冠舒展度则显著降低。邻体竞争强度越大,针叶树树冠的偏移与缺失程度越大。当针叶树受到强烈的侧方竞争时,对象木树冠和树干的径向生长显著受阻,表现为树冠舒展度大幅度下降、高径比显著提高,使树冠向细高方向发展。当针叶树上方的生长空间被占据时,其轴向生长同样受到严重阻碍,树木的冠径比和高径比维持较稳定状态。总体而言,四种针叶树种在视觉形态上对竞争胁迫的响应具有一定差异性,其中油松最为敏感,圆柏次之。综上,在城市森林微景观中,邻体竞争会导致针叶树种的树冠及树形发生明显变化,这种变化主要受综合资源竞争的影响,与其周围潜在生长空间的大小及对称性有关。在城市森林景观营建时,建议将针叶树栽植在对称的竞争环境中,但是其邻体木不宜过高,通过四周邻体木的适度竞争,能够促进针叶树的轴向生长,同时降低树冠偏移或变形的风险,提高其视觉美学效果。

中国北方针叶林碳通量动态变化及其影响因素分析

基于北方针叶林典型站点——呼中定位观测站2014~2018年不同时间尺度碳通量观测数据,探究了该生态系统长时间序列碳通量动态变化及其影响因素。结果表明:受总初级生产力(Gross Primary Productivity,GPP)和生态系统呼吸(Ecosystem Respiration,RE)的综合作用影响,北方针叶林生态系统净碳交换量(Net Ecosystem Exchange,NEE)年际变化差异较大,在2.64~17.63 g(C)m^(-2) a^(-1)之间波动;从季节上看,在生长季(6~8月)GPP值大于RE,北方针叶林以净碳吸收为主,在非生长季,NEE与RE相等,北方针叶林为弱碳源;逐日尺度上,NEE呈倒“U”形变化特征,RE和GPP则呈“U”形特征。日尺度NEE主要受净辐射、相对湿度、气温、土壤温度等因素影响,这些环境因素构建的回归方程可以解释45.19%的NEE日变化;月尺度上NEE主要受净辐射、相对湿度、气温3个因素影响,回归方程可以解释78.42%的NEE月变化。

森林公园林分改造技术及初期效益评价研究——以佛山市云勇生态林养护中心项目为例

习近平总书记强调,为促进生产力发展,要有效保护、优化生态环境。林业建设与经济社会发展密切相关,推动林业建设是落实生态文明建设目标的关键途径。现阶段,社会各界对绿色高质量生态产品的需求逐渐加大,所以在林业工作中,要将培育优质森林、建立功能多样且稳定的森林生态系统作为根本任务。基于此,本文主要以佛山市云勇生态林养护中心项目为例对森林公园林分改造技术的应用进行探究,并全面评估项目的初期效益,以期为相关人员提供参考。

千岛湖马尾松次生林抚育改造种群结构变化研究

为分析马尾松次生林抚育改造的林分密度、树种结构及其空间布局的动态变化,评估马尾松次生林改造成效。以千岛湖的5块马尾松天然次生林改造典型样地为研究对象,2008年在实施林分改造前布设每个30 m×30 m大小的样地,同年冬季间伐、次年春节补植,至2023年进行复位监测,调查林分改造前后样地的林分生长情况,求得树种重要值,分析直径、树高构成以及群落混交度、大小比数、角尺度等空间结构。结果表明:①千岛湖区马尾松次生中龄林间伐并补植阔叶树种,经过14年生长,林分密度提高72.88%;②林分改造后马尾松的重要值从61.308下降至26.754,同时其他常绿针叶树种重要值也同步下降,而常绿、落叶阔叶树树种均有一定程度上升,木荷、石栎的重要值提高6.81%;檵木、短柄枹之类灌木、阔叶小乔木的重要值增幅高达84.81%;③马尾松抚育补植第14年的群落直径分布特征呈“L”形,高度级个体数呈塔型,下层幼树较多,复层结构明显;④平均混交度抚育前为0.42,抚育后混交程度提高至0.72。受优势木增加且补植阔叶树生长的影响,群落的大小比数分化明显。群落的平均角尺度从抚育前的0.59下降至抚育后的0.356,由聚集分布向均匀分布转变。指出了马尾松次生林间伐并补植阔叶树种有利于改善林分结构,提高林分生产力和生物多样性,未来千岛湖马尾松次生林或将以针阔叶树种混交并与小乔木、灌木共同构建复层林方向演替为常态。

National Forest Inventories capture the multifunctionality of managed forests in Germany

Background:Forests perform various important ecosystem functions that contribute to ecosystem services.In many parts of the world,forest management has shifted from a focus on timber production to multi-purpose forestry,combining timber production with the supply of other forest ecosystem services.However,it is unclear which forest types provide which ecosystem services and to what extent forests primarily managed for timber already supply multiple ecosystem services.Based on a comprehensive dataset collected across 150 forest plots in three regions differing in management intensity and species composition,we develop models to predict the potential supply of 13 ecosystem services.We use those models to assess the level of multifunctionality of managed forests at the national level using national forest inventory data.Results:Looking at the potential supply of ecosystem services,we found trade-offs(e.g.between both bark beetle control or dung decomposition and both productivity or soil carbon stocks)as well as synergies(e.g.for temperature regulation,carbon storage and culturally interesting plants)across the 53 most dominant forest types in Germany.No single forest type provided all ecosystem services equally.Some ecosystem services showed comparable levels across forest types(e.g.decomposition or richness of saprotrophs),while others varied strongly,depending on forest structural attributes(e.g.phosphorous availability or cover of edible plants)or tree species composition(e.g.potential nitrification activity).Variability in potential supply of ecosystem services was only to a lesser extent driven by environmental conditions.However,the geographic variation in ecosystem function supply across Germany was closely linked with the distribution of main tree species.Conclusions:Our results show that forest multifunctionality is limited to subsets of ecosystem services.The importance of tree species composition highlights that a lack of multifunctionality at the stand level can be compensated by managing forests at the landscape level,when stands of complementary forest types are combined.These results imply that multi-purpose forestry should be based on a variety of forest types requiring coordinated planning across larger spatial scales.

Forest land use discontinuity and northern red oak Quercus rubra introduction change biomass allocation and life strategy of lingonberry Vaccinium vitis-idaea

Background:Multi-purpose use of forests in a sustainable way forces a recognition of how introduction of alien woody species in forests with different land use histories affect native plants other than trees.Lingonberry Vaccinium vitis-idaea is an important understory component of temperate and boreal forests and provider of valuable non-wood forest products.Here we studied effects of land use changes and introduction of Northern red oak Quercus rubra on lingonberry in mesic Scots pine forests(in central Poland).We measured lingonberry cover,height of shoots,biomass of stems and leaves,and fruit productivity.Shoots were collected within 200 research plots located in recent and ancient Scots pine forests,with and without Q.rubra.Results:We found that V.vitis-idaea reached lower cover,aboveground biomass and fruit production in recent than ancient forests and in forests with than without Q.rubra.The fruit production in recent pine forest was only 2%of that reported in ancient pine forest,and V.vitis-idaea did not reproduce generatively in forests with Q.rubra.Biomass and carbon sequestration of V.vitis-idaea in forests with alien(invasive)trees decreased by 75%compared to ancient pine forest.Effects were also clear at the individual shoot level–in less suitable conditions we found taller heights and higher biomass allocation into stems than foliage.Biomass allocation in fruiting and non-fruiting shoots in pine forests was also different–less of the dry biomass of fruiting shoots was allocated to leaves than to stems.Conclusions:In the age of high interest in ecosystem services and discussions about usage of alien tree species as alternatives in forest management,our results clearly indicate disruption of ecosystem services provided by V.vitisidaea in the presence of Q.rubra.Lingonberry benefited from the continuity of forest land use,however,regardless of land-use legacy,alien tree introduction led to decline in abundance of species crucial for ecosystem functioning.Therefore,to maintain valuable native species and for conservation of ecosystem services delivery,we suggest limiting the introduction of Q.rubra in areas with abundant V.vitis-idaea,especially in forests with continuous forest land-use history.

i-Tree Eco Analysis of Landscape Vegetation on Remediated Areas of Oak Ridge National Laboratory

The Oak Ridge National Laboratory (ORNL) is the largest and most diverse energy, research, and development institution within the Department of Energy (DOE) system in the United States. As such, the site endures constant land development that creates rigorous growing conditions for urban vegetation. Natural resource managers at ORNL recognize that trees are an integral component of the landscape and are interested in characterizing the urban forest and their associated ecosystem services benefits. We evaluated the urban forest structure, quantified ecosystem services and benefits, and estimated economic value of resources using i-Tree Eco at ORNL. While this assessment captured over 1100 landscape trees, the ORNL Natural Resources Management for landscape vegetation can be expanded to include unmanaged landscapes, e.g. riparian areas, greenspace, and other vegetative attributes to increase ecosystem services benefits. Assigning a monetary value to urban forest benefits help to inform decisions about urban forest management, ideally on cost-benefit analysis.

Trees and Shrubs of Zerafshan State National Reserve, Uzbekistan

The riparian (tugai) forest ecosystems of Central Asia are a biodiversity hotspot with unique many trees and shrubs. Intense human pressure and global warming have caused habitat destruction in Zerafshan State National park and it’s 23.5 ha. There grow more than 300 higher plants. We analysed the wild flora and the remains of the species diversity that previously existed on the site of the forestry enterprise, the modern biodiversity of trees and shrubs in the described territory are represented by 52 species from among representatives of 21 plant families. These monitoring and results indicated that some tree species might in the near future become extinct in the wild. We therefore recommend that the local people be encouraged to stop using these trees.

Evaluating Structural and Temporal Factors Affecting Supply of Ecosystem Benefits in a University Urban Environment in South Carolina, USA

Sustainable urban forest management is still an evolving concept, particularly as it pertains to a sustainable supply of ecosystem benefits and management planning. Urban forestry maintains a greater human dimension component than traditional timber-oriented rural forestry because urban trees grow in city centers and neighborhoods, supplying critical ecosystem benefits to the population centers. The overall goal of this study was to evaluate the relationship of urban forest stand structure and its temporal dynamics with the sustainable supply of ecosystem benefits in university environments. Individual tree data were collected from a completed inventory, while the i-Tree Eco model was used to generate ecosystem benefits data from the Clemson urban forest. The cumulative-benefits supply curve had an inverted J-shaped curve, but the average supply curve had a negative slope against the species richness. Likewise, individual tree variables total height, DBH, leaf area, and crown height strongly correlated with the total ecosystem services supply. Based on the temporal supply trends, the study area trees were broadly segmented into three groups: establishment, growth, and legacy, with 65%, 31%, and 4% frequency distribution, respectively. Urban forest managers need to identify forest management goals and preferred ecosystem benefits among the urban communities to guide the required forest structure and dynamics to ensure a sustainable and functioning urban forest.

森林每木生物量数据质控方法和技术研究

【目的】野外森林生态站乔木生物量长期动态观测数据,对于支撑中国典型森林碳储量、森林生产力等分析研究具有重要价值。每木生物量(Tree biomass weight,TBW)数据是估算森林生物量的基础。TBW数据质量是其长期观测的生命线,也是生物量数据相关科学研究获得正确结论的基础。【方法】TBW数据质控方法的研究、数据质控标准的建立和数据质控信息技术手段的使用,是提升TBW数据质量的三个方面。本文首先介绍中国生态系统研究网络(CERN)森林生态站TBW数据生产过程、TBW数据模式和数据项标准化内容,然后介绍TBW数据质控总体框架及质控方法,最后介绍信息技术(基于OLE编程、Python多进程计算)在TBW基础与实测数据质控及在派生数据自动核验方面的应用。【结果】本文实现了TBW数据一致性、准确性的快速检查,有助于形成标准化的数据质控业务流程,对于海量的森林生态站多样地TBW数据的高效质控和快速计算具有重要参考价值。

竞争对天然针阔混交林树木直径生长的影响

为探究不同竞争水平条件时天然针阔混交林中主要组成树种单木直径生长的变化规律,将竞争因子作为重要影响因素来构建天然针阔混交林单木直径生长模型。根据穆棱林业局44块天然针阔混交林固定样地的3期调查数据,利用方差分析分别比较了不同竞争强度时红松(Picea koraiensis)、冷杉(Abies nephrolepis)、云杉(Picea koraiensis)、桦木(白桦(Betula platyphylla),枫桦(Betula costata))、椴树(糠椴(Tilia mandshurica),紫椴(Tilia amurensis))、色木槭(Acer mono)、其他树种间直径生长量的差异,利用最小二乘法建立了与距离无关的单木直径生长基础模型,然后构建树种哑变量单木直径生长模型,并以此为基础引入样地随机效应因子构建样地水平混合效应模型。使用独立检验数据对基础模型、哑变量模型、混合模型进行检验。结果表明:天然针阔混交林各树种间直径生长量不同,随竞争强度的增大,各树种直径生长量均显著降低。不同树种在同一竞争强度下直径生长量不同,所有林木断面积之和(B_(AL))≤9 m^(2)时,其他树种的直径生长量最大,色木槭的最小;9 m^(2)<B_(AL)≤36 m^(2)时,云杉的直径生长量最大,色木槭的最小;36 m^(2)<B_(AL)≤45 m^(2)时,色木槭的直径生长量最大,桦木的最小。与基础模型相比,哑变量模型在保证预估精度的同时能够体现树种间直径生长量的差异,其决定系数(R^(2))从0.6115提高到0.6425,均方根误差(ERMS)从0.7669 cm下降到0.7360 cm;混合效应模型的R^(2)从0.6425提升到0.6627,ERMS降低到0.7149 cm,提高了模型的预测精度。在天然针阔混交林中,所有树种直径生长量均随竞争强度的增大而减小,但不同树种间存在差异。包含哑变量的线性混合效应模型可以提高天然针阔混交林的单木直径生长模型预测精度,能较好地描述天然针阔混交林树木直径生长过程。