太行山石灰岩中山区树种选择研究初报

对石灰岩中山区两个立地条件，包括干旱阳坡２４个水保林树种，阴坡９个造林树种进行了综合评分。结果为干旱阳坡乔木树种以樟子松、侧柏、油松得分最高，分别为４．８６、４．４３、４．２９；小乔木及灌木树种以沙棘、翅果油树、荆条得分最高，分别为３．７１、３．４３、３．２９；阴坡以樟子松、油松、沙地柏得分最高，分别为５．０、４．０、３．２９。在选择造林树种时，除参考综合评分外，还应考虑立地条件，造林目的和造林方法，以及树种特性和经济价值加以选择。     

平潭岛岩质海岸造林树种生长及适应性评价

为了积累基岩海岸生态恢复经验,改善沿海困难立地的生态环境,对平潭岛临海石质山体造林乔木和灌木树种的生长情况进行了调查,并对其适应性进行了分析。结果表明:岩质海岸不同乔木和灌木造林均表现出较高的保存率,其地径和树高生长比初植时均有显著提高,生态恢复成效显著;通过树种的适应性评判,4种乔木树种的适应性排序为木麻黄台湾相思肯氏南洋杉龙柏,4种灌木树种的适应性排序为黄栀子滨柃夹竹桃海桐。     

苏北地区常绿树种造林应用情况调查分析

对徐州、宿迁和连云港3市近年来造林绿化工程中常绿树种应用情况进行的调查分析结果表明,常绿树种应用频度在94.1%,其中乔木树种的应用频度达88.5%,一般常绿乔木的应用数量已占全部乔木数量的1/3至2/3。3市造林中使用的常绿树种有35种,其中乔木树种只有14种,灌木21种,乔木树种中女贞应用频度最高(75%),其次为雪松、香樟和广玉兰;灌木树种应用频度最高的为红叶石楠,其次为大叶黄杨和海桐;香樟在苏北地区冻害严重,生长势很差。     

西安城市及郊野绿化树种的调查研究

1979年10－11月，在西安市区和郊区以及临潼骊山，华阴华山等进行了集体或分组调查，市区调查树木共3，402株，其中针叶乔木298株，8．8％，常绿阔叶乔木157株，占1．6％，落叶乔木1，795株，占52．8％，常绿灌木203株，占6．0％，落叶灌木760株，占22．3％；藤木189株，占5．5％，在西安市，共调查园林树木275种（变种，变型在内），均按统一表格详细记载，在市区及郊野共记载百年以上的古树74株，其中最老的是一株2，000年生汉槐，对西安市区及郊野调查结果进行了分析，并提出关于西安市基调树种和各类型绿地骨干树种的建议。     

论山东沿海防护林体系建设的树种选择

分析了限制沿海防护林树种选择的5个方面的障碍因素;阐述了沿海防护林的树种选择原则;分别就山东沿海防护林建设中可选的乔木、灌木、草本植物资源作了介绍;指出了提高沿海防护林造林成活率的2种造林方法:容器苗造林和根际覆盖技术。     

适于滇西北造林的6类乡土灌木树种

从生态与经济效益兼备的原则出发，推荐了适于滇西北造林的6类乡土灌木树种。通过对这些树种生态习性、利用价值等的介绍，从而提出了其作为本区经济林的下层树种以及固土保水造林树种的推广应用。     

科尔沁沙地耐旱乡土灌木树种的选择及其生长比较

在干旱年份，从科尔沁沙地干燥沙丘选择特别耐旱的灌木树种进行育苗试验。通过对1、2年生苗木生长状况分析：叶底珠（Securinega suffruticosa）、鼠李（Rhamnus porflorus）、桃叶卫矛（Evonyms bungeanus）、驼绒蒿（Eurotia arborescens）和杠柳（Periplocasepium）等适应性强，1年生苗木高度为对照树种胡枝子的49．6％～101．8％，2年生苗木为对照树种胡枝子的89．0％～97．9％，可以进一步进行沙地造林试验；东北木蓼生长缓慢，不宜继续进行造林试验。     

温州乔木树种资源与开发利用调查

在乔木、灌木树种资源调查的基础上，筛选出适应自然环境生长的152种乔木树种；按树种资源的基本特点，并根据立地条件，分3类阐述树种选择依据和分布现状，提出开发利用意见。     

浅谈达茂旗造林树种的选择

达茂旗由于降水量小、蒸发量大,"十年九旱"很难适应高大乔木生长,实生树种极少,只能在个别地区少量生长榆树、杨树,大面积造林树种只能选择灌木柠条。文章通过分析达茂旗气候、水资源、树种分布状况,以及回顾了达茂旗林业走过历程与得失,阐明"适地适树"树种选择重要性,指出今后要重点发展以柠条为主的灌木林,借鉴"径流林业"的思想并对造林后期管理提出建议。     

玉江高速公路两侧绿化初探

玉江高速公路两侧绿化面积为39.81 hm2,选择绿化造林树种37种,株数777 639株,野花组合87.2 kg。文中阐述了树种选择、树种配置、树种混交方式、整地和挖塘规格、砌花台、客土以及栽植技术等高速公路两侧绿化中的具体做法。经过近3年的精心抚育管护,大乔木和小乔木的成活率和保存率均达100%,灌木和藤本植物的成活率和保存率达95%以上,超过国家标准。通过多树种(草种)的混交造林配置模式,形成复层林分结构,增加了生物多样性,提高了土壤蓄水保水能力,对稳定路基起到重要作用。     

武夷山国家级自然保护区植物物种多样性研究

以植物群落调查样地资料为基础，从不同类型、不同层次的物种丰富度、多样性指数及均匀度指数对武夷山国家级自然保护区植物群落多样性进行了分析。本区植物群落多样性的变化规律为：物种丰富度、多样性指数及均匀度随该区植被演替趋势从针叶林、针阔叶混交林到常 阔叶林而增加，群落间变幅较大；植物生长型在物种丰富度、多样性指数及均匀度等多样性指数上均表现出灌木层＞乔木层的规律。毛竹林作为一种重要的植被类型，其灌木层物种多样性高于其它3种森林类型，但由于毛竹是无性繁殖，其在林分中占绝对优势，故乔木层物种多样性明显低于其它3种森林类型。     

濒危植物大花黄牡丹与生境地群落特征的关系

在濒危植物大花黄牡丹生境地群落学调查的基础上,划分生境地群落类型,分析生境地群落特征,探讨大花黄牡丹与生境地群落特征的相互关系。研究结果表明:TWINSPAN将大花黄牡丹生境地群落划分为乔木群落和灌木群落。乔木群落中大花黄牡丹多度显著低于灌木群落,但大花黄牡丹平均胸径和平均高则与灌木群落无显著差异。群落特征与大花黄牡丹的相关性分析表明:大花黄牡丹多度及平均胸径与群落总多度、灌木多度及乔木物种丰富度存在显著的相关性,而大花黄牡丹多度与乔木多度存在显著负相关,大花黄牡丹平均胸径与群落平均高也存在显著负相关,大花黄牡丹平均胸径及平均高与藤本物种丰富度则存在显著的正相关,具有相关性的变量之间可用不同的回归方程较好的表述。此外,大花黄牡丹冠幅面积、高度、丛数及幼苗数量均与灌丛的冠幅面积存在显著的正相关,但大花黄牡丹幼苗数量在两种群落间无显著性差异。     

宝天曼植物群落物种多样性研究

对宝天曼保护区植物群落物种多样性进行了研究。结果表明 ,物种丰富度指数、多样性指数和均匀度指数在群落梯度上的分布趋势基本一致 ,较好地反映了不同植物群落类型在物种组成方面的差异。草本层物种丰富度指数明显高于乔木层和灌木层 ,草本层物种丰富度指数在群落梯度上的变异最大 ,灌木层次之 ,乔木层最小。乔木层物种多样性指数小于灌木层和草本层 ,草本层和乔木层物种多样性指数在群落梯度上的变异程度明显大于灌木层。灌木层物种均匀度指数大于乔木层和草本层 ,草本层和乔木层均匀度指数在群落梯度上的变异程度大于灌木层。物种丰富度指数和多样性指数的较大值出现在高海拔和低海拔群落 ,较小值多出现在中等海拔群落。物种均匀度指数的较小值多出现在中等海拔群落 ,但其较大值在各海拔群落都有分布。草本层物种丰富度指数和多样性指数的较高值多分布在低海拔群落 ,较小值多分布在中等海拔群落 ;乔木层和灌木层的各种指数以及草本层的物种均匀度指数在海拔梯度上的分布规律不明显     

大关县3种筇竹群落生物多样性研究

对大关县乔木-筇竹群落、灌木-筇竹群落和筇竹-草本群落3种群落,采用二元属性数据测度方法进行了生物多样性的调查。结果表明:3种筇竹群落类型中以乔木-筇竹群落物种总种数(178种)为最多。各层次物种丰富度的顺序依次为,乔木-筇竹群落的物种丰富度为乔木层>草本层>灌木层;灌木-筇竹群落和筇竹-草本群落的物种丰富度一致,其物种丰富度顺序依次都为灌木层>草本层>乔木层。乔木-筇竹群落的乔木层的Shannon-Wiener(H’)指数最高,灌木-筇竹群落的灌木层和草本层的H’指数最高,筇竹-草本群落各层的H’指数都较低。灌木-筇竹群落与筇竹-草本群落在环境梯度上不同点之间的共有种最少,相似性最低,群落间的差异大,群落间物种替代速率较高。     

浙江丽水太山褐叶青冈林群落结构及其多样性

通过样方调查,应用物种丰富度、物种多样性指数和群落均匀度等指标对分布在浙江丽水太山山地的褐叶青冈林群落类型进行了分析.结果表明:太山山地褐叶青冈林物种丰富;乔木层优势种群明显,树高分布主要以近似对称分布为主,群落乔木层个体高度的分布较为均匀;在群落的垂直结构上,灌木层、乔木层、草本层的物种多样性依此降低,灌木层的物种丰富度和物种多样性指数最大;在各样方中,乔木层、灌木层和草本层的物种多样性没有明显的变化趋势;群落生活型以中、小高位芽植物为主,群落叶的性质以单叶、革质和全缘的小叶为主;群落优势种群年龄结构和群落类型属于衰退型.     

冰砬山天然次生林群落结构与物种多样性特征

根据在辽宁冰砬山16块天然次生林样地的调查数据,对天然次生林的植物群落结构和物种多样性特征进行了研究,测定了各层次植物物种的重要值,采用多种方法计算各层次物种的丰富度指数、均匀度指数和多样性指数。结果表明:冰砬山天然次生林群落成层现象和各层次优势种比较明显,依重要值排序乔木层优势种为蒙古栎和紫椴,亚优势种为花曲柳、色木槭和怀槐;灌木层优势种为斑枝卫矛、金银忍冬、胡枝子和金刚鼠李,亚优势种为刺五加和胡榛子;草本层优势种为羊胡苔草。该地区天然次生林群落植物物种比较丰富,丰富度指数草本层最高,乔木层和灌木层较接近;均匀度指数和多样性指数灌木层最高,草本层最低,乔木层居中。     

Woody Plants Diversity and Possession,and Their Future Prospects in Small-Scale Tree and Shrub Growing in Agricultural Landscapes in Central Highlands of Ethiopia

Woody plants diversity and possession in small-scale tree and shrub growing practices among farmers of central highland Ethiopia were assessed by using a complete census of the trees and shrubs existing on farmers’ lands. The future prospects of diversity and possession of woody plants in the agricultural landscapes were also investigated by using the farmers’ species preferences and seedling demands as indicators. Comparisons were made across wealth classes, proximity clusters to a nearby state forest and land uses. It was found that 27 tree and 21 shrub species exist on lands of the studied households. With increasing wealth status of the households, the tree and shrub species richnesses increased. Tree and shrub species richnesses were highest in boundary plantings and homesteads respectively. Small-scale woodlots had the highest number of tree stems while homesteads contained the highest number of shrub stems. The number of tree stems a household possesses is strongly influenced by distance from the state forest, family size, educational level of the household head and number of iron-roofed houses owned. And, the shrub stems possession is significantly influenced by wealth status, distance from the state forest, land holding size, family size, livestock holding, age of wife and possession of off-farm income sources. The species preference analysis and seedling demand computations indicated that the woody species diversity is less likely to change in the future because there is no difference between the currently existing species and the preferred ones. Nonetheless, the number of tree and shrub stems on the farmers’ holdings could increase if the seedling demands of the preferred woody species are met.     

A comparison of riparian plant community response to herbivory by beavers (Castor canadensis) and ungulates in Canada's boreal mixed-wood forest

Herbivores, such as beavers (Castor canadensis) and ungulates, can dramatically alter the species composition and structure of riparian vegetation communities. We examined how four different levels of beaver presence and ungulate density influenced the structure and composition of riparian vegetation communities in the mixed-wood boreal region of east-central Alberta, Canada. Beavers, as central-place foragers, focus on similar species utilized by the six ungulate species in our study area. However, we found that vegetation responded differently relative to the percent cover and heights of emergent, shrub, herbaceous dicots, and tree species depending on the varying combinations of beaver presence and ungulate densities. There was an obvious negative effect of ungulate herbivory on shrub heights and cover; however, we were unable to find any significant effects on the overall composition and structure of vegetation communities that were exclusively related to beaver activities. In areas with no beavers and lower ungulate densities there was a positive growth response in preferred species (e.g., Salix spp., Prunus spp.), which clearly demonstrated the degree of combined influence that these herbivores have on riparian communities. In these areas, Salix spp. was four times shorter than in areas where beavers were not present and ungulate densities were lower. In addition percent cover was lowest for emergent vegetation and herbaceous dicots in areas with higher ungulate densities. Many studies focus on single-species effects on forage resources, yet our research shows that the study of combined effects of multiple herbivores can provide a new insight into these complex systems.     

Socio-economic factors affecting smallholder tree planting and management intentions in Leyte Province,Philippines

Survey data have been collected from four rural communities in Leyte Province, the Philippines, on household tree planting and management intentions, as well as the socio-economic characteristics, attitudes to tree planting and management, farming practices and the number of trees planted. In relation to intended tree planting and management activities, respondents were asked a series of structured questions as to what tree species they intend to plant, how many individual trees of each of those species they plan to plant, and for what purpose they propose to plant each of the tree species. This paper reports the results of analyses of the stated tree management intentions of households in the four communities and identifies the socioeconomic factors that influence householders’ tree management intentions. Respondents were generally enthusiastic about the possibility for further tree planting on their land, 75% indicating they would undertake planting. About 60% indicated an interest in commercial tree farming, with no significant differences in this level of interest between communities. It was found that a number of socio-economic variables indicating higher levels of land ownership and previous experience in the forestry industry are related to the intention to plant trees to produce timber for sale. These include the use of materials from public lands, participation in community organisations and community forestry programs, and the present management of trees to produce timber for sale.     

Species frequency of communities along northern slope of Changbai Mountain, Northeast China

IntroductionAs an important index reflecting species spatialpatterns, frequency reflects not only the importanceof species, but also the evenness of spatial distribution in community (Lin 1986, Magurran 1988; Dale1999). Frequency figure could reveal the complexityand diversity of community at some extent. Raunkiaer(1918) divided frequency indices into five classes,namely, Ac 1%-20%, Ba 21%-40%, Cd 41%-60%, Da61%-80%, and Ed 81%-100%, and based on 8 078frequency indices of herbaceous vegetat…