里生茶秆竹立竹度与生产力关系的研究

通过建立野生茶秆竹立竹度与生产力的数学模型，发现不同立地的茶秆竹立竹度与新竹数量、平均胸径、平均高存在着二次抛物线关系，为不同立地的茶秆竹林经营提供科学理论依据。     

福建酸竹地上生物量积累分配特征及其异速生长关系

为摸清福建酸竹生物量积累与分配特征,测定了1~4年生福建酸竹的秆、枝、叶生物量,分析了立竹地上构件生物积累与分配特征及其相对生长关系。结果表明,不同年龄福建酸竹构件含水率、生物量及其分配比例与相对生长关系差异明显。随立竹年龄增加,秆、枝、叶含水率明显下降,而其生物量及总生物量则显著增加;秆生物分配比例及异速生长指数总体下降,而枝、叶生物量分配比例及其异速生长指数总体升高。综合分析表明,福建酸竹丰产林经营宜多留养2年生、3年生立竹,适量留养4年生立竹。     

四季竹立竹地上现存生物量分配及其与构件因子关系

通过对四季竹立竹构件因子和地上生物量的调查,分析了立竹地上现存生物量分配格局及立竹构件因子与构件生物量的关系。结果表明:地上现存生物量分配格局1年生立竹为竹秆>竹叶>竹枝,2年生立竹为竹叶>竹秆>竹枝,2年生立竹竹秆和竹叶生物量分配比例较1年生立竹分别极显著减少和增加,而竹枝生物量分配比例不同年龄立竹间无显著变化。2年生立竹各构件因子与构件生物量间大多呈显著或极显著相关,立竹全高、枝下高、枝盘数是立竹胸径的从属因子,立竹胸径对立竹构件生物量和地上部分总生物量起着决定作用,两者具有极显著的三次曲线函数关系。四季竹在资源分配时对竹叶构件的倾斜有利于种群对已占领生境的巩固和新生境的开拓。     

大头典竹地上部分生长指标与生物量关系研究

对大头典竹1a、2a、3a及〉3a4个龄级立竹地上部分各器官含水率和生物量调查分析,结果表明：1a生大头典竹竹秆与枝条含水率最高,随着竹龄的增长秆和枝含水率逐渐下降,以秆含水率下降最明显。竹秆生物量占地上部分生物量比例随竹龄增加而降低,枝条生物量占地上部分生物量比例随竹龄增加而升高。各龄级立竹胸径、全高均与地上器官生物量和地上部分总生物量呈显著相关关系。利用相对生长模型回归分析,得出回归方程,通过F检验,均达到显著水平,可用以估算大头典竹生物量。     

茶秆竹生物量模型研究

在标准地调查的基础上，应用多种数学模型对茶秆竹各器官生物量进行相关性分析，建立了茶秆竹各器官间的咽归模型。可用于一定立地条件下的茶秆竹的生物量估测。     

马来甜龙竹地上部分含水率及生物量研究

对马来甜龙竹1年生、2年生、3年生3个龄级立竹不同径级地上部分各构件含水率和生物量进行测定分析,结果表明:1年生竹地上竹秆、枝条和叶片含水率明显高于2年生和3年生竹;同龄竹比较,竹秆含水率最高;竹秆生物量占地上部分生物量比例随竹龄增加而降低;马来甜龙竹地上各部分生物量之间呈极显著相关关系。经生长模型分析结果表明,可利用胸径和秆高估算立竹地上各部分生物量及总生物量。     

天然大节竹林群落林分结构规律的研究

中华大节竹（Indosasasinica）为大中型散生竹类，生长较好的天然竹林主要集中在云南河口大困山海拔400—1000m地区，面积达8580多公顷，具有很高的开发价值。本文根据实测资料，对其林分密度、直径、秆龄、叶面积指数、生物量等因子的变化规律及其相互关系首次进行了系统研究，列出了相应的公式及计量数表。     

粉单竹秆形结构与生物量

在广西南宁市测量粉单竹竹秆的全高、材长、胸径、节间数量及每节间三要素（直径、长度和壁厚）等秆形指标，对砍倒的立竹进行分段称重，研究这些指标与竹材生物量的关系。结果表明：材长、节间数量及三要素均与胸径相关密切，幂函数和线性方程拟合程度高。最长节间出现在第9~12节，最粗直径多在第4~6节。全株生物量中竹秆所占份额最大，为76.82%，各器官生物量依次为秆 > 蔸 > 枝 > 叶。单株竹秆鲜质量与胸径高度显著相关，可用二次线性方程进行较精确估算。研究秆形结构变化规律、全株及每段竹秆鲜质量分配格局，有利于促进粉单竹竹秆科学利用。     

筇刺竹生物学特性的研究

本文根据作者在云南南部筇刺竹集中分布地区所做的调查观测,对筇刺竹的生物学特性,包括形态特征、生态习性、个体结构规律和发笋率与竹丛结构因子的关系进行了分析研究。研究结果表明：筇刺竹是我国南部热区的适生竹种,尤其适于在河谷地带、盆地边缘和低山丘陵地区发展;筇刺竹秆形指标（ｆ１．３）为０．６９５,明显大于其它相近竹种或树木;竹秆最大直径和最长节间出现于秆之中部;胸径与秆高呈指数函数关系,可用Ｈ＝２．２４６４７３Ｄ０．９２６７２５来表达;胸径与秆重呈正线相关,可用Ｗ＝０．１９３３９５（Ｄ２Ｈ）０．６９０４０４来表达;竹丛发笋率、成竹率与秆丛密度和竹丛平均秆径有较密切的关系。本文对竹笋采收指数与老秆采伐年龄的确定进行了探讨     

广东茶秆竹材性分析及开发利用研究

物理力学性能测试结果表明，茶秆竹的密度为0.873g/cm3，抗弯强度和抗弯弹性模量分别达到了276.6MPa和21060MPa，属于常见竹种中的优良品种。结合广东省丰富的茶秆竹资源，分析了深入开发茶秆竹的意义，并在此基础上提出了开发茶秆竹家具、竹纤维、高档竹制品及竹生态旅游等方面的建议。     

Biomass and nutrient allocation in Douglas-fir and amabilis fir seedlings: influence of growth rate and nutrition

Allocation of biomass and nutrients to shoots and roots was followed for three years in fast and slow growing populations of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), a fast growing pioneer species, and amabilis fir (Abies amabilis Dougl. ex J. Forbes), a slow growing shade-tolerant species. Seedlings were grown for three seasons in five nutrient treatments containing varying proportions of nitrogen and phosphorus (N:P). In both species, growth was greatest in the 250:20 N:P treatment followed by the 100:60 and 100:20 treatments. Vector analysis showed that, in both species, relative to the 100:20 treatment, seedlings in the 20:20 treatment were N deficient and seedlings in the 100:4 treatment were P deficient, i.e., where deficiency is defined to mean that an increase in nutrient supply increases nutrient content, nutrient concentration and plant dry weight. Seedlings in the 100:60 treatment had a higher P content than seedlings in the 100:20 treatment but the same dry weight, indicative of what Timmer and Armstrong (1987) termed luxury consumption. No nutrient retranslocation was observed in either species until the third growing season. In Douglas-fir, the greatest percentage of nutrients was exported from one-year-old shoots between May and July of the third growing season to support new growth. The total amount and percent of nutrients retranslocated was higher in Douglas-fir than in amabilis fir. Amabilis fir seedlings also exported N and P from older shoots, but this was later partially replenished. In both species, P retranslocation was greatest in treatments with a high N:P ratio. Nitrogen retranslocation was greatest in amabilis fir seedlings in treatments with a low N:P ratio, and greatest in Douglas-fir seedlings in the 250:20 and 100:60 treatments. Potassium retranslocation was correlated with seedling size. Douglas-fir retranslocated more of its shoot N reserves into new growth at the expense of older needles when soil fertility was high and sinks were strong. Otherwise, both species preferentially translocated the elements in short supply. Thus, retranslocation varied with the ecological characteristics of species, the relative availability of soil nutrients and sink strength.     

茶杆竹的叶面积指数测定

用剪纸称重法实测茶杆竹各径阶标准竹叶面积，竹子叶面积与直径成直线回归关系。回归方程为：y=38553.97 6194.93x，根据该方程计算可列出茶杆竹直径与叶面积关系表，从而可计算林分叶面积与叶面积指数。     

福建茶秆竹林的土壤水文效应

对福建茶秆竹的土壤水文效应进行了分析研究.结果表明：福建茶秆竹林土壤容重、孔隙状况、入渗性能等反映土壤水文效应的指标均高于杉木林和松杂林.土壤贮水量2 612.5 t/hm2,比杉木林、松杂林分别增加了55.3%和52.3%.福建茶秆竹既是优良的经济竹种,也是一种土壤水文效应良好的竹林.     

大花蕙兰、蝴蝶兰在湖州地区的引种栽培及适应性分析

浙江省湖州林科所于2000年首次引进栽培大花蕙兰与蝴蝶兰,共引进了6个品种的大花蕙兰和3个系列的蝴蝶兰.通过引种、栽培及适应性分析,认为湖州地区发展大花蕙兰和蝴蝶兰是可行的,生产的花品质高,经济效益明显.     

Branch growth and biomass allocation in Abies amabilis saplings in contrasting light environments

Aboveground biomass allocation, and height and branch growth were studied in saplings of the shade-tolerant conifer, Abies amabilis Dougl. ex Forbes growing in large openings and in the understory of an old-growth forest in western Oregon. The presence of annual overwintering budscale scars was used to infer extension growth histories; annual growth rings in branches and stems were used in combination with extension histories to compute partitioning of new biomass among leaves, branches and stems. Saplings growing in large gaps had conical crowns, whereas understory saplings had umbrella shaped crowns as a result of much greater rates of branch extension than stem extension. Understory saplings grew slowly in height because of low rates of biomass production and low allocation of biomass to stem extension. About 40% of new biomass was allocated to foliage in both groups, but understory saplings allocated more of the remaining growth increment to branches and less to stem than did saplings growing in large gaps. These results differ from the patterns observed in shade-tolerant saplings of tropical forests, where allocation to foliage increases with shading and branch allocation is much lower than observed here. This difference in allocation may reflect mechanical constraints imposed by snow loads on the evergreen A. amabilis crowns, particularly on flat-crowned understory saplings.     

广宁茶秆竹地上生物量分布特征研究

Based on the diameter, height and biomass of different organs of Pseudosasa amabilis, an individual optimization model is established. The results showed that the relationships among diameter, height, and biomass of different organs followed the power function model, rather than exponential model, linear model, or polynomial model. The biomass proportion of large diameter grade increased apparently after culm harvesting, and diameter was mainly distributed from 4 to 5 cm diameter grade. The standing biomass of cultivated Pseudosasa amabilis was between 48.10 t·hm^-2 and 53.10 t·hm^-2, while standing biomass of non cultivated P. amabilis stand was between 66.90—70.40 t·hm^-2, which is a suitable species for carbon sink. Bamboo individual biomass accounted for 70% of the above-ground biomass and grew multiply as the individual bamboo diameter increasing. The biomass of litter ranged from 8.32% to 18.10% in standing biomass while that of non cultivated bamboo stands was lower than that of cultivated bamboo. There existed a 1∶ 1 constant relationship between leaf biomass and branch biomass.     

Temporal variation and efficiency of leaf area index in young mountain Norway spruce stand

Temporal variation of leaf area index (LAI) in two young Norway spruce stands with different densities was monitored during eight consecutive growing seasons (1998–2005). We focused on: (1) LAI dynamics and above-ground mass production of both spruce stands and their comparison, (2) leaf area duration (LADU), crop production index (CPI) and leaf area efficiency (LAE) evaluation, and (3) thinning impact on the above-mentioned parameters. Also, we tried to deduce the most effective LAI value for the Norway spruce forest investigated. The LAI values of both spruce stands showed a typical seasonal course. To describe the LAI dynamics of the stand, we recommend taking LAI measurements within short time intervals at the time of budding and needle expansion growth (i.e., in early spring) and close to the LAI peak, when the twig growth has been completed. The reason was that after reaching the seasonal maximum, no significant differences between subsequently obtained values were found in the following 2 months. Therefore, we recommend this period for the estimation of seasonally representative LAI values, enabling the comparison of various spruce stands. The maximum hemi-surface LAI value reached 12.4. Based on our results, the most effective LAI values for maximum above-ground biomass production were within the range of 10–11. We found an LAI over these values to be less effective for additional production of above-ground biomass. In forest practice, thinning intensity is mostly described by percentage of stocking reduction. We want to show that not only thinning intensity, but also the type of thinning is important information. The type of thinning significantly affected the stand above-ground biomass increment, canopy openness, stand LAI and LAI efficiency. The stimulating effect of high-type thinning was observed; the LAE as well as the CPI increased. Low-type thinning had no such effects on LAE increments compared to the high-type thinning with similar intensity.

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Oaks (Quercus spp.) in northeast China

There arc eight species and four varieties of oak in northeast China. This paper reports and describes the distribution and phylocoenogenesis of the Korean pine-broadleaved mixed forest and the mongolian oak formation. The close relationship between the flora of Ussuli—Amur region and Japan is discussed. Analyses of heat and energy balance, and biomass of mongolian oak forests arc provided. Many measurements indicate that, in a nonclosed stand, the wood production of a stand is positively correlated with leaf area index (LAI).     

Biomass production potential of three short rotation woody crop species under varying nitrogen and water availability

A study was conducted in an agricultural field to examine the biomass production of three fast-growing short rotation woody crop (SRWC) species, Populus deltoides, Quercus pagoda, and Platanus occidentalis using fertilization and irrigation (fertigation). The study included a randomized complete block (RCB) with five treatments; control, irrigated, and irrigated with 56, 112, and 224 kg nitrogen (N) ha⁻¹ year⁻¹. We quantified survival, basal area, standing biomass, aboveground net primary productivity (ANPP), leaf area index (LAI), and growth efficiency (GE) for each species along the soil nitrogen and water gradient. P. deltoides had low rates of survival (83, 82, and 77% years six, seven, and eight, respectively), but had production values greater than Q. pagoda and P. occidentalis. Standing biomass reached its peak for P. deltoides and P. occidentalis (17.56 and 10.36 Mg ha¹, respectively) in the irrigation treatment, and in the 112 kg N treatment for Q. pagoda (5.42 Mg ha⁻¹). P. deltoides and P. occidentalis ANPP peaked in the irrigation treatment (6.66 and 6.31 Mg ha⁻¹ year⁻¹, respectively) and in the 112 kg N (4.43 Mg ha⁻¹ year⁻¹) for Q. pagoda. ANPP was correlated with LAI; however, the relationship was species specific. Maximum ANPP was reached below the maximum LAI for Q. pagoda and P. occidentalis. P. deltoides ANPP was highest at the maximum LAI, which was achieved with IRR. These results suggest that species-specific cultural practices producing optimum LAI and maximum ANPP should be identified before fertigation techniques are adopted widely for SRWC production on agricultural fields.     

Assessing forest structure and function from spectral transmittance measurements: a case study in a Mediterranean holm oak forest

Annual changes in structural attributes and seasonal dynamics in water content, photosynthetic rate and light-use efficiency (LUE) were assessed by spectral transmittance for 4 years (1999-2003) in six stands of a Mediterranean holm oak forest. Green biomass, total biomass and leaf area index (LAI) were determined. In 1999, seasonal dynamics of net carbon dioxide (CO2) exchange and water content were measured. We recorded photosynthetically active radiation (PAR) transmittance and hyperspectral transmittance in the 400-1100 nm region and derived reflectance-based vegetation indices. Transmittance over the PAR region derived from either ceptometer or spectroradiometer measurements (PART and TPAR, respectively) was related to green and total biomass. Both PART and TPAR were also related to LAI (r=0.79 and r=0.70, respectively, P <0.001) and were appropriate for comparison among stands, whereas subtle changes in LAI within a stand were better assessed by the transmittance amplitude in the red edge region (TRE) (within a stand, r=0.77-0.99, P <0.001). Spectral transmittance-based indices successfully captured physiological processes that occurred on temporal (seasonal) and spatial scales. The transmittance-based water index (TWI) was related to both foliage and canopy water content (r=0.69, P <0.001). Estimates of foliage and canopy water content improved in dense (closed) stands (r=0.84 and r=0.87, respectively, P <0.001) compared with low-density stands. Under non-drought conditions, transmittance-based photochemical reflectance index (TPRI) was related to LUE (r=0.58, P <0.05) and net CO2 exchange (r=0.72, P <0.01), and the combined TPAR x TPRI index greatly improved these relationships (r=0.93 and r=0.84, respectively, P <0.01), indicating that both structural and physiological adjustments modified CO2 fixation capacity in these forest stands. Our novel approach to the study of transmitted radiation provides a tool for estimating structural and functional variables such as LAI, LUE and water content, which are key determinants of terrestrial productivity.