昌宁县华山松数量化立地指数表编制

林业生产中,不仅需要评定有林地的立地质量,也需要对无林地的立地质量进行评价,以便合理利用土地,为充分发挥宜林地的生产潜力和适地适树进行造林提供科学依据。为此利用标准地主要环境因子与其地位指数间的相关关系,编制此表,作为评价森林立地质量、预测林地生产力、造林规划设计、森林经营管理等重要依据。编表方法是利用地形、土壤等主要因子为自变量,按地位指数表查定各标准地的地位指数作为因变量,采用数量化理论(Ⅰ)求解,编出标准年龄时华山松立地指数得分表。     

广东杉木立地指数与环境及土壤因子的关系

立地指数是以林木生长指数反映立地质量的一种数量指标,它受环境和土壤因子所制约,在编制立地指数表的同时,若能找出影响立地质量和林木生长的主导因子,分析它们之间的相互关系,建立数学模式,可作为预测林木生长,评价立地质量和确定如何提高林地生产力的依据。本文为在编制广东杉木立地指数表的过程中,对影响立地质量的环境及土壤因子进行统计分析,选出主导因子,据此确立数学模式,以供广东选择杉木立地时参考。     

天然常绿阔叶林数量化地位指数表的编制

数量化地位指数表是评价森林立地质量、预测林地生产力的一种森林经营数表,在立地分类和评价、造林规划设计以及森林经营管理等方面已得到了广泛的应用。论文采用数量化方法,以常绿阔叶林树高为因变量,立地因子为自变量,建立回归模型,通过岭回归筛选出主导因子：腐殖质厚度、海拔、坡度、树龄、土壤类型5个因子,然后以主导因子与树高建立预测方程,编制出了南平市延平区天然常绿阔叶林数量化地位指数表,该地位指数表经检验符合精度要求。     

衡阳地区杉木立地评价及其应用

对湖南衡阳市三个不同地貌区域的山区、孤山区及丘陵区，分别进行了立地质量评价调查研究，共取样地３６２块，优势木、解析木３６２株，并应用多元统计分析，对影响杉木生长的主导立地因子作了筛选，结果认为影响衡阳市杉木生长主导立地因子是中地貌、坡位、坡形、开阔度（ｍ）及土壤腐殖质层厚度与土层厚度。并以中地貌为依据划分了三个立地类型区；以坡位划分立地类型组；以坡形与土壤划分立地类型，同时编制了地位指数表，用以预测立地生产力。从评价立地质量得出，发展杉木以重山区生产力为最高，地位指数１４以上的立地占３５％以上；孤山及丘陵区只占３％～１５％。孤山及丘陵区不宜大面积发展杉木，只宜局部地方种植。     

西畴县杉木立地指数表及数量化地位指数方程

立地指数是衡量林分生产力和评价林地质量的客观标尺,也是各立地因子特定组合在林木生长上的反映。通过编制立地指数图表,对有林地进行林木生长与环境因子的调查,建立立地指数与立地因子的经验式—地位指数方程,估测各立地条件组合的立地指数,即可将有林地的调查结果应用于无林地,为造林地的规划设计提供依据。这是当前用材林基地建设中的一项急待开展的工作。     

三江平原丘陵区长白落叶松适生立地条件分析

在三江平原丘陵区佳木斯市孟家岗林场对不同立地条件下长白落叶松人工林生长指标进行标准地调查,建立立地指数导向曲线方程、同形立地指数族、立地指数表和优势木高与立地因子间的数量化模型,在此基础上,评价立地因子对落叶松生长的影响,得出影响落叶松生长的主要立地因子依次为坡向、土壤A层厚、坡度和坡位,适宜落叶松生长的立地是坡度平缓土层深厚的阴坡中下部。     

基于林分潜在生长量的立地质量评价方法与应用

【目的】提出一种基于林分潜在生长量的立地质量评价方法,为精准提升森林质量提供可靠依据。【方法】首次严格定义潜在立地生产力概念,推导出潜在生产力和现实生产力的模型和计算方法,提出立地元素-林分元素-林分生长类型-现实生产力和潜在生产力模型-落实到地块的立地质量制图技术流程,并以吉林省针阔混交林为例,利用4期一类清查固定样地数据,基于林分潜在生长量的立地质量评价方法开展案例研究。【结果】影响吉林省林地立地质量的主要立地因子包括地貌、海拔、坡位、坡度、土壤类型和腐殖质层厚度;采用立地类型约束的树高生长分级法,将6个因子组合的立地类型分为5个等级,针阔混交林不同立地等级的林分平均高、断面积和蓄积量生长模型具有较好的生物学意义和统计可靠性,决定系数(R~2)分别为0.991 8、0.986 6和0.984 2; 5个立地等级的潜在蓄积生产力在3.6～5.8 m~3·hm~(-2)a~(-1)间,并给出了立地潜在生长量对应的合理林分密度。【结论】基于林分潜在生长量的立地质量评价方法适用于纯林和混交林,可以回答一定立地的最大生产力及现存林分通过密度调控可以提高多少生产力。     

土壤因子对落叶松林分生长的影响

落叶松是吉林省主要造林树种之一。它生长快、质量好,主要分布在本省的中,东部地区。为探讨土壤、立地诸因子与林分生长的关系,以评定落叶松生长条件。通过土壤、立地、测树等因子,用数量化方法编制立地指数表,由得分表中偏相关系数大小,可知诸因子与林分生长的紧密程度,立地指数表得分的高低,将反映不同立地条件对林分生长的关系,分数高,贡献大,它们之间的关系就密切,较能定量的分析各因子与林分生长的关系,从而对立地产量的予测、立地质量的评价、适地适树的造林设计、因林制宜地管理现有林分等方面提供依据。     

立地指数—环境因子模型评价森林立地生产力研究进展

立地质量评价和林分生产力预估对于树种选择、森林经营决策至关重要。目前常利用优势高直接估测立地指数以评价同龄纯林立地生产力,而对于混交林、异龄林、无林地以及随时间不断变化的立地则很难用该方法进行立地质量评价,往往通过立地指数—环境因子模型模拟,应用环境因子预测立地指数。文中简述了环境因子与立地指数关系研究概况,从研究尺度、数据来源、关键环境因子选择、预测模型及其拟合评价等方面进行综述,并讨论和展望了立地指数—环境因子的未来研究重点,以期为我国人工林立地质量评价和科学经营提供参考。     

用模糊关系方程法作地位指数预报

地位指数表或地位级表是目前评定立地质量的二种用表。这两种表都是依赖于林分的平均优势高或林分平均高与林分平均年龄的关系来编制的,都能在有林地中使用。但是,无法使用于无林地,更不能估计各立地因子对林木生长作用的大小。近年来,许多研究表明,对无林地的立地质量评定,判定各立地因子对林木生长作用大小,可通过地位指数与立地因子的关系来建立数学模型解决。本文应用模糊(Fuzzy)关系方程对立地质量评价问题进行探讨。     

淮北平原砂姜黑土兰考泡桐立地分类与评价及生长模型的研究

兰考泡桐（Paulowniaelongata）是淮北平原砂姜黑土上的主要造林树种．为了提高造林质量，提高林业经营与决策的科学水平，开展了该区兰考泡桐立地类型划分、立地质量评价及生长模型的研究．通过调查该立地上兰考泡桐的生长情况．应用数量化理论筛选该类土壤影响兰考泡桐生长的主导因子，划分了9个立地类型．应用Richards函数为导向曲线，以平均优势木胸径为评价指标，导出了地位指数模型．编制了数量化地位指数得分表，实现了有林地与无林地的统一评价．根据兰考泡桐在这一地区栽培密度小的特点，建立了平均本胸径和平均本材积的单木生长模型．     

Analyses of the impact of changes in atmospheric deposition and climate on forest growth in European monitoring plots: A stand growth approach

During the last 15 years a number of studies have shown increasing forest growth in central Europe, rather than a decline as was expected due to negative effects of air pollution. We have here used data from intensive monitoring plots spread over Europe for a five year period in order to examine the influence of environmental factors on forest growth. Evaluations focussed on the influence of nitrogen, sulphur and acid deposition, temperatures, precipitation and on a drought index calculated as deviation from the long-term mean. The study included the main tree species Norway spruce, Scots pine, common beech as well as European and sessile oak and was based on data from 363 plots. As many other factors besides nitrogen and temperature influence tree growth, expected stem volume increments were modelled using site productivity, stand age and a stand density index. Relative volume increment was then calculated as actual increment in % of expected increment. The site productivity, assumed to be given by site conditions and past environmental conditions, was either taken from expert estimates or computed from site index curves from northern, central and southern Europe. The model explained between 18% and 39% of the variance with site productivity being positively related and age negatively related to actual increment. The various models and statistical approaches were fairly consistent, and indicated a fertilizing effect of nitrogen deposition, with slightly above one percent increase in volume increment per kg of nitrogen deposition per ha and year. This was most clear for spruce and pine, and most pronounced for plots having soil C/N ratios above 25. Also, we found a positive relationship between relative increment and summer temperature, i.e. May–August mean temperature deviation from the 1961–1990 means. The cause–effect relationship here is, however, less certain. Other influences were uncertain. Possibly, sulphur and acid deposition have effects on growth, but these effects are obscured by, and outweighed by the positive effect of nitrogen deposition, because of collinearity between these variables. Drought effects were uncertain also, and one reason for this might be large uncertainties in the precipitation data: precipitation measured on some 50% of the plots correlated poorly with the precipitation data obtained from Europe-wide databases. The major finding of this study was a positive relationship between higher than normal volume increment on one hand and nitrogen deposition on the other hand.     

Modelling the site index of Pinus pinaster plantations in Turkey using ecological variables

The determination of site productivity in forest ecosystems plays a crucial role in resource management.This study was carried out to identify relationships between site characteristics and height growth of Corsican maritime pine(Pinus pinaster Ait.) plantations in Turkey.Sixty-nine sample plots 20 years of age were selected from locations with different inclinations,aspects,elevations,slope positions and site class.Soil samples were taken at various depths.Height and age were measured on a dominant tree after felling in each plot.Physical and chemical properties of the soil were determined.Relationships between site index(SI_(25)) and physiographic factors,climatic attributes as well as soil properties were evaluated using correlation analysis and multiple regression analysis.Site index was significantly related with annual precipitation,mean spring rainfall,rainfall June to September,rainfall of the driest month,length of the dry period,mean maximum temperature,mean temperature of the warmest month,stoniness of the soil,sand,silt,clay,pH,electrical conductivity,and available water capacity.Multiple regression accounted for 57.9% of variations in height growth.The models obtained can be used to determine the site index of potential areas in Turkey for maritime pine.It can be said that the productivity of maritime pine may decline in the future due to global climate change.     

耐寒桉树立地类型划分及评价

采用聚类分析和逐步回归分析的方法,分析影响桉树生长的主导因素,确定立地分类系统,划分立地类型,评价生产力。根据桉树立地条件分析结果,提出了以海拔、局部地形、土壤因素为主的三级分类系统。本分类系统按海拔划分出2个类型区,以坡位划出6个类型组,以土壤温度、成土母质和腐殖质层厚度划分出26个主要立地类型。     

美国卡罗莱纳州南部海岸地区火炬松立地质量评价(英文)

Eleven soil types, which can be identified and delineated using conventional soil survey procedures, were characterized for loblolly pine （Pinus taeda L.） productivity. Four 4-hectare study sites, each containing four measurement plots, were established for every soil type studied. In a stepwise multiple regression, both soil parent material （i.e. a combination of subsoil texture and geology） （p〈0.001）, and drainage class （p=0.006） were significant predictors of site index （tree age 25）, and the overall linear regression model had an R2 value of 0.55. The extremes of soil parent material differed by 3.9 m site index （loamy subsoil on the Wicomico-Penholoway surfaces versus clayey subsoil on the Pamlico-Princess Anne surfaces）. Each increment of drainage class differed by 0.7 m site index. For example, a poorly drained soil had 0.7 m lower site index than a somewhat poorly drained soil. For seven of the eleven soil types studied, there is greater than 80% probability that estimated mean site index is within ±0.8 m of the actual soil type mean site index. The other four soil types （labeled G, I, C and K） need to be either redefined or sampled more intensively. Two of these need to be subdivided in order to adequately characterize site quality, one based on geology （Soil type G） and one based on soil drainage class （Soil type I）. Variation in soil drainage class and varying amounts of topsoil displaced into windrows were both factors influencing site quality variation of a third soil type （Soil type C）. The wide variation in site index data for a fourth soil type （Soil type K） appeared to be due, in part, to sampling study locations and individual measurement plots with less than optimum bedding and/or artificial drainage. Soil parent material （subsoil texture and geology） along with drainage class were found to be important factors influencing site quality on the South Carolina Lower Coastal Plain.     

广西大青山西南桦人工林土壤养分特征及其与立地生产力的关系

[目的]探讨西南桦人工林对土壤的适应性及土壤养分特征,揭示土壤养分状况与立地生产力的关系,为其造林地选择及人工林养分管理提供参考。[方法]在广西大青山林区西南桦人工林内设置47块600 m2的典型样地,调查常规测树因子,采集土壤样品,测定10项常规土壤化学性质指标;按照土壤养分分级标准评价土壤养分状况,基于立地指数将样地分为高产和低产组,进一步比较分析两组立地间各养分指标的差异性,探讨土壤养分对立地生产力的影响。[结果]表明:广西大青山西南桦人工林地土壤绝大部分为强酸性,有机质、有效N、全N含量中等偏上,有效P甚缺,其它养分含量中等偏下。高产和低产立地间土壤有机质和全K含量均呈极显著差异(P0.01),有效N含量差异显著(P0.05)。[结论]西南桦对于低pH值、低P含量的土壤具有较强的适应性;有机质、全K和有效N含量是影响广西大青山西南桦人工林立地指数的关键土壤养分因子。     

立地条件对落叶松人工林生长的影响

通过对日本落叶松(Larix kaempferi)人工林在不同立地条件下的生长调查,结果表明,日本落叶松在生长过程中,受土层厚度、林地位置、立地指数等多方面因素的制约:厚层土胸径年生长量比中层土和薄层土高9.2%～26.7%,树高年生长量高21.8%～44%;生长在N坡,坡度较缓、山地下腹为优;在不同的立地指数级中,生长差异明显,18以上指数级比14～18指数级胸径生长量高25.4%,比14以下指数级胸径生长量高33.8%,树高生长量,18以上指数级比14～18指数级高26.7%,比14以下指数级高36.3%。培育日本落叶松人工林,选择优质立地条件不但可提高林木的生长速度,又能促使林木优质高产。