四种针叶低效林单株生长模型构建

以碳汇林基线情景低效针叶林,包括日本落叶松、杉木、马尾松、湿地松为研究对象,利用收集和调查的生物量与解析木实测数据,选择不同数学模型,通过曲线回归、非线性回归方法拟合模型参数,建立4个树种的单株生物量模型、胸径生长模型和树高生长模型。结果表明:4个树种的单株生物量模型、胸径生长模型采用相关系数较高、MSE值最小的幂函数模型、S模型拟合效果最好;4个树种的树高生长模型形式各异,日本落叶松、湿地松以Logistic模型拟合效果最好,杉木以抛物线模型拟合效果最好,马尾松以S模型拟合效果最好;检验结果表明,所建日本落叶松、杉木、马尾松、湿地松的生长模型预估精度均达到了95%以上,且都通过了F检验。     

一平浪林场云南松单株木生长规律初步研究

通过对一平浪林区云南松的林分调查以及树干解析,分析了林分的树高、直径生长过程,结果表明,云南松生长发育过程可划分为苗木生长初期.树高速生期、直径速生期、速生后期和成熟期5个生长阶段.前5年为苗木生长初期,5～10 a是林分开始郁闭.高生长明显加快,10～25 a期间,云南松直径生长量也开始达高峰期,需要加强抚育管理措施;25～45 a期间,直径旺盛生长,树高保持一定生长量,而材积生长量保持最大,其后云南松进入速生后期,生长渐趋于缓慢,但仍保持较高的生长量.表明云南松速生期较长,可作长轮伐期经营,是培育大径材的理想树种.     

阔叶树人工幼林生长调查与分析

阔叶树人工幼林生长调查与分析欧阳遂华薛朝荣（江西省遂川县五指峰林场３４３９０９）关键词：人工幼林阔叶树生长情况１基本概况五指峰林场海拔４００～１０００ｍ，平均坡度２６°，土壤为黄红壤，土层厚１ｍ左右，石砾含量２５％，腐殖质层４０～６０ｃｍ。原生植物群...     

杉木与阔叶树混交林初期生长效应分析

在不同试验地开展杉木(Cunninghamia lanceolata)与红锥(Castanopsis hystrix)、闽楠(Phoebe bournei)、刨花润楠(Machilu spauhoi)和马褂木(Liriodendron chinense)混交林早期生长效应研究.结果表明,杉木生长量在贝江河林场和山口林场...     

湖南主要阔叶树材微观构造的研究

对湖南 19科 2 8属 3 4种主要阔叶树材的微观构造进行了研究 .结果表明 :单位面积管孔数及导管分子长度与管孔直径成反比 ;各种类型轴向薄壁组织所占比率 ,按从小到大排列顺序为轮界型 <傍管型 <离管型 ;按纤维长度分级 ,各级所占比率按从大到小排列顺序为中等 >长 >甚长 >极长 ;按宽度分级 ,各级所占比率按从大到小排列顺序为细 >中 >粗 >甚粗 ;纤维长宽比 >45 ;射线高度的变化规律是 ,单列、二列射线的木材所占比率 ,按从小到大排列顺序为环孔材 <半环孔材 <散孔材 ,多列射线的木材所占比率 ,按从小到大排列顺序为环孔材 <散孔材 <半环孔材 ;纤维微纤丝角度较小     

马尾松与4种阔叶树混交林生长效果调查分析

对马尾松与4种阔叶树种混交效果进行了试验研究。结果表明,马尾松与枫香、黄檀、麻栎混交后,促进马尾松生长效果显著,混交林中马尾松的平均胸径和平均树高都显著大于纯林,林分生产力高,结构稳定。而马尾松与马褂木行状混交林郁闭后,马尾松的生长受抑,平均胸径和平均树高都低与其纯林,林分分化严重,稳定性差。     

阔叶树对红阔混交林生长的影响

栽红保阔是培育速生丰产阔叶红松林的根本途径。红松进入速生期后，在红松保存率较高的前提下，每公顷保留带状或块状阔叶树４００～６００株，红阔株数比５：１～４：１，上方郁闭度０．２～０．３较为适宜。降低红松分权率积极主动的措施是营造混交林，加强幼林保护，人工修枝，防治病虫危害。     

山西省辽东栎单株木生长模型研究

辽东栎(Quercus wutaishansea Mary.)是山西森林分布最广泛的阔叶树种之一,兼具生态价值和良好的经济价值。通过对山西省部分山区66株辽东栎进行树干解析,选取40株辽东栎生长数据作为建模样本,其余26株作为检验样本,选择常用的6个生长方程进行拟合。结果显示,Gompertz方程拟合辽东栎胸径生长,Richards方程拟合树高和材积生长效果最好。对所选模型进行独立样本检验,相应方程的拟合精度都在95%以上。利用模型绘制辽东栎生长曲线,得出山西省辽东栎在20-55年进入胸径生长的高峰期,9-33年进入树高生长高峰期,第51年时,材积的年生长量达到最高峰,当年生长量可达0.009m³。辽东栎在生长83年后,其材积的连年生长量开始小于年平均生长量,达到适宜采伐树龄。     

红锥等5种阔叶树种早期生长比较试验

2001～2004年，在中山市5个点进行红锥等5个阔叶树种生态适应性栽培试验。结果表明：各树种适合在中山生长，地点、树种间各生长量存在极显著差异。树种间比较以红锥和格木生长最好，山乌桕较差；地点间比较以南朗立地树种生长最好，坦洲立地生长最差。文中还分析了5个树种早期生长节律。     

沧州市公园绿地速生树种、中生树种、慢生树种调查

结合文献调查法、比较研究法、实地调研法对沧州市区7个公园进行了实地调查,对公园绿地中速生树种、中生树种与慢生树种的配置情况进行了分析,并针对存在的问题提出了意见和建议,为今后公园绿地建设中科学选择树种、合理配置植物提供参考。     

基于混合效应的湖南马尾松次生林单木生长模型

[目的]建立湖南省马尾松次生林单木断面积与材积生长模型,为林木的生长预估提供理论依据.[方法]以湖南省2014年一类清查样地中的20块马尾松次生林为研究对象,选取5个具有生物学意义的生长方程,建立马尾松断面积和材积随年龄变化的基础模型,在此基础上,加入以样地为随机效应的随机参数,构建基于混合效应的湖南马尾松次生林单木断...     

The impact of atmospheric deposition and climate on forest growth in European monitoring plots: An individual tree growth model

In the climate change discussion, the possibility of carbon sequestration of forests plays an important role. Therefore, research on the effects of environmental changes on net primary productivity is interesting. In this study we investigated the influence of changing temperature, precipitation and deposition of sulphur and nitrogen compounds on forest growth. The database consisted of 654 plots of the European intensive monitoring program (Level II plots) with 5-year growth data for the period 1994–1999. Among these 654 plots only 382 plots in 18 European countries met the requirements necessary to be used in our analysis. Our analysis was done for common beech (Fagus sylvatica), oak (Quercus petraea and Q. robur), Scots pine (Pinus sylvestris) and Norway spruce (Picea abies). We developed an individual tree growth model with measured basal area increment of each individual tree as responding growth factor and tree size (diameter at breast height), tree competition (basal area of larger trees and stand density index), site factors (soil C/N ratio, temperature), and environmental factors (temperature change compared to long-term average, nitrogen and sulphur deposition) as influencing parameters. Using a mixed model approach, all models for the tree species show a high goodness of fit with Pseudo-R² between 0.33 and 0.44. Diameter at breast height and basal area of larger trees were highly influential variables in all models. Increasing temperature shows a positive effect on growth for all species except Norway spruce. Nitrogen deposition shows a positive impact on growth for all four species. This influence was significant with p < 0.05 for all species except common beech. For beech the effect was nearly significant (p = 0.077). An increase of 1 kg N ha⁻¹ yr⁻¹ corresponds to an increase in basal area increment between 1.20% and 1.49% depending on species. Considering an average total carbon uptake for European forests near 1730 kg per hectare and year, this implies an estimated sequestration of approximately 21–26 kg carbon per kg nitrogen deposition.     

An application of Neurogenetic Algorithm System to individual tree growth model

A neural network system with genetic algorithms (Neurogenetic Algorithm System, or NGAS) was employed to develop individual coniferous tree growth models. A multivariable regression model was applied to compare the performance of NGAS. An IBM personal computer with the BioComp System’s software program of NGO was used to execute this comparison. The results indicate that NGAS is more accurate and effective than the conventional regression method in modeling individual tree growth based on the criteria of Sum of Squared Error (SSE), Average Absolute Error (AAE), Mean Squared Error (MSE) and Final Predicted Error (FPE). This study also suggests that individual tree growth may indeed be a non-linear process. Using this flexible neural network system to model individual tree growth can yield satisfactory prediction results.     

A basal area increment model for individual trees growing in even- and uneven-aged forest stands in Austria

Because of the gradual shift from pure even-aged forest management in central Europe, existing yield tables are becoming increasingly unreliable for forest management decisions. Individual tree-based stand growth modeling can make accurate stand growth predictions for the full range of conditions between pure even-aged and mixed-species uneven-aged stands. The central model in such a simulator is basal area increment for individual trees. Spatial information is not needed, and age and site index are intentionally not used to gain generality for all possible stand conditions. A basal area increment model is developed for all the main forest species in Austria: spruce (Picea abies), fir (Abies alba), larch (Larix decidua), Scots pine (Pinus sylvestris), black pine (Pinus nigra), stone pine (Pinus cembra), beech (Fagus silvatica), oak (Quercus robur, Quercus petraea and Quercus cerris), and for all other broadleaf species combined. The Austrian National Forest Inventory provided 5-year basal area increment from 44 761 remeasured trees growing on 5416 forested plots in the 1980s. This large sample is representative of forest conditions and forest management practices throughout Austria and therefore provides an excellent data base for the development of an increment model. The resulting increment model explained from 20 to 63% of the variation for all nine species and from 33 to 63% of the variation if the minor species Pinus cembra is excluded. These results compared quite closely with those of Wykoff for mixed conifer stands in the Northern Rocky Mountains. In the Austrian model, size variables (breast height diameter and crown length) accounted for 14–47% of the variation in basal area increment, depending on tree species. The best competition measure was the basal area of larger trees, which provides a tree-specific measure of competition without requiring spatial information; crown competition factor provided only minor improvement. Competition variables accounted for 9% of the variation on average, and up to 15% for some species. Topographic factors (elevation, slope, aspect) explained up to 3% of the variation, as did soil factors. Remaining site factors; such as vegetation type and growth district accounted for a maximum of 3% of the variation in increment. In total, site factors explained from 2 to 6% of the variation. Even though site factors account for a small percentage of the variation, they are not only significant, but serve to localize a particular prediction. These species-specific interrelationships between basal area increment and the various size, competition, and site varibles correspond quite well with ecological expectations and silvicultural understanding of these species in Austria. Because the sample base is so strong, the resulting growth models can be recommended not only for all of Austria but for surrounding regions with similar growth conditions.     

Modeling individual tree height growth of Norway spruce and Scots pine from national forest inventory data in Norway

We developed individual tree height growth models for Norway spruce (Picea abies (L.) Karst.) and Scots pine (Pinus sylvestris L.) in Norway based on national forest inventory data. Potential height growth is based on existing dominant height growth models and reduced due to competition by functions developed in this study. Three spatially explicit and two spatially non-explicit competition indices were tested. Distance effects and diameter ratio effects were estimated from the data simultaneously with parameters of the potential modifier functions. Large height measurement errors in the national forest inventory data caused large residual variation of the models. However, the effects of competition on height growth were significant and plausible. The potential modifier functions show that height growth of dominant trees is largely unaffected by competition. Only at higher levels of competition, height growth is reduced as a consequence of competition. However, Scots pine also reduced height growth at very low levels of competition. Distance effects in the spatially explicit competition indices indicated that the closest neighbors are most important for height growth. However, for Scots pine also competitors at larger distance affected height growth. The five competition indices tested in this study explained similar proportions of the variation in relative height growth. Given that unbiased predictions can only be expected for the same plot size, we recommend a spatially explicit index, which describes the distance function with a negative exponential, for use in growth simulators.     

柳杉单立木生长模型拟合的初步研究

采用Richards、Logistci、Mitscherlich、Gompertz、Modified—Weibull等5种生长函数对柳杉的直径、树高、材积三个因子生长过程进行拟合以确定其适宜的生长模型。得出：Richards和Gompertz生长函数较适宜柳杉单木生长过程的拟合，而Richards生长函数则在生长过程的拟合和预测两方面都佳。     

Fire sensitivity of broadleaf tree species in plantations of Kurdistan,Iran

To better manage wildfires and plantations in Kurdistan, native tree species commonly used in planting and reviving forests such as Quercus brantii Lindl., Q. infectoria Olivier, Q. libani Olivier, Pistachio atlantica Desf., Fraxinus rotundifolia Vahl, and Robinia pseudoacacia L. were evaluated and compared in terms of fire sensitivity and fire resistance. To determine fire sensitivity, indices such as the fl ammability index, ignition time, fl ame durability, moisture content, carbonized surface, mass reduction, bulk density, as well as dry weight of wood, bark, and leaves were used. The data were subjected to ANOVA. The means obtained, after examining homogeneity or heterogeneity of the variances, were compared using parametric and nonparametric comparison tests. There was a significant difference at the level of 5%. Based on the analysis of these indices, the species could be divided into three groups: species sensitive to fire such as Robinia pseudoacacia, species moderately sensitive to fire such as F. rotundifolia, and species relatively resistant to fire, including Q. brantii, Q. libani, Q. infectoria, and P. atlantica.     

帽儿山林木生长及抚育的研究

笔者提出了饱和接近率的概念 ,可以用于描述林木间竞争的强度 ,并可用于发现那些接近于停滞生长的林木 ,以便在抚育间伐时将这些林木伐去 ;笔者还对三种常用的生物生长模型分析了内在的缺点 ,即生长速率与生物年龄无关。为了体现年龄对生物生长的影响 ,应在生长方程的右边乘上年龄因子t-b。     

湖南省现有森林植被主要树种的碳含量

探讨了湖南省现有森林植被17种树种(杉木、马尾松、湿地松、柏木、乐昌含笑、红花木莲、樟树、桢楠、甜槠、青冈栎、木荷、杜英、山矾、枫香、拟赤杨、杨树、毛竹)各器官的碳含量及其各器官碳含量的算术平均值。结果表明:同一树种不同器官碳含量差异不显著,不同树种各器官碳含量由高至低的排序不完全一致,不同树种同一器官或同一树种不同器官碳含量算术平均值存在一定的差异;针叶树、常绿阔叶树、落叶阔叶树和毛竹各器官碳含量(g·g-1)的变化范围分别为0.491~0.566,0.421~0.549,0.449~0.550,0.470~0.496,各树种种内各器官碳含量算术平均值在0.486~0.551 g·g-1之间变化,柏木最高,毛竹最低;针叶树碳含量高于阔叶树、毛竹,各树种树干碳含量普遍较高于其它各器官,变化范围在0.493~0.556 g·g-1之间,地上部分碳含量普遍高于相应树种的地下部分;17种树种各器官碳含量的算术平均值为0.504 g·g-1。