Partial cutting as a conservation alternative for oak (Quercus spp.) forest—Response of bryophytes and lichens on dead wood

Semi-open oak-rich forests may support many species adapted to large trees and coarse woody debris. Currently many oak-rich forests in northern Europe have more or less closed canopies due to lack of natural and cultural disturbances. In these forests, conservation oriented partial harvesting of biofuel may restore a desired forest structure and light regime that potentially may favour many species that have declined during the last century. We quantified effects of such cutting on lichens and bryophytes living on dead wood in southern Sweden, using a design with paired cutting and control plots (each 1 ha) in 15 forests. In each plot we surveyed the same five logs and three stumps before and after harvest (25% of the tree basal area removed). The epixylic species composition shifted towards a flora typical for dryer dead wood. The mean species number of lichens per stump increased (clear effect) and the mean number of bryophytes per stump decreased (nearly significantly) due to harvesting. The species composition, but not species richness, on logs was affected. No increases or decreases in species of conservation concern could be detected. Since the overall negative effects were weak, we suggest that partial harvesting of dense oak forests is compatible with maintenance of the diversity of lichens and bryophytes on dead wood. However, the amount of such forest harvested needs to be carefully assessed in relation to demands of other taxa.     

Effect of clear-cutting on the understory vegetation,soil and diversity of litter beetles in scots pine-dominated forest

Currently, the aim of modern forest management is not only timber production but also the protection of biodiversity. The initial effects of clear-cut logging on forest understory vegetation, soil and the diversity of litter beetles have been studied. We examined unstudied effects of clear-cutting disturbance on understory vascular plant species abundance, forest soils, and understory vegetation nutrients as well as beetle diversity one year after clear-cutting. Substantial changes in the prominence values and above-ground mass of forest-related vascular plant and moss species were detected. Clear-cuttings resulted in fast appearance of new light-loving plant species. The significant decrease in understory plant biomass influenced the reduction of nutrient pools in clear-cut areas after one year. The clear-cut logging negatively influenced the richness of species and the number of individuals of stenobiontic forest-related beetles in the forest litter. However, forest clear-cuttings were beneficial for eurytopic and open land species.     

马尾松阔叶树混交林不同更新方式对林分生长的影响

通过对将乐县马尾松阔叶树混交林进行天然更新、人工促进天然更新和人工营造杉木林等3种更新方式的林分恢复调查,比较探讨其生长量、生物量及物种丰富度,结果表明：不同更新方式对林分生长、林下植物发育及林分物种丰富度影响较大,采用天然和人工促进天然更新形成的阔叶树林分树种多样,结构稳定,生长良好,是保护和发展阔叶林的一种有效途径。     

The role of indigenous trees for the conservation of biocultural diversity in traditional agroforestry land use systems: The Bungoma case study: In-situ conservation of indigenous tree species

In order to precisely assess the role of agroforestry for the conservation of (agro-)biological diversity there is a need to adjust sampling methods used in plant sociology. This study is on the contribution of agroforestry land use to the in-situ conservation of indigenous trees within a typical East-African smallholder farming system in Western Kenya. A modified approach to measuring species richness and abundance is presented. The selection of tree-rich structures was done according to management patterns rather than considering syntaxonomic classifications from the vegetation science point of view. This approach, which is better suited to the strongly human-influenced vegetation of agroecosystems, employs between-management unit diversity measures to help evaluate abundance and constancy of species in particular management units. The predominant off-farm vegetation patterns are riverine forests, rocky hillsides, hedgerows, wooded grassland relicts, woodlands or colline forest relicts and tree groves whereas the noticeable tree-rich on-farm management units are homegardens, homesteads, life fences, coffee- and banana-groves and annual cropping fields. 98% out of all indigenous tree species known from Bungoma, occur in off-farm lands. 53% of the indigenous tree species occur in tree rich on-farm management units while 47% of the indigenous trees are dependent on the maintenance of off-farm lands. Hedgerows embody the most promising secondary vegetation structure that shows ample potential to accommodate a wide range of indigenous perennial species outside the natural vegetation formations. The pattern of distribution of various vegetation structures, and the mixture with diverse tree-based on-farm plots are interesting features in regard to floristic and eco-diversity on a landscape level. In this respect, three areas that show different population densities and distinct agro-historical conditions were compared. In regions of particular high population density the degree of association of various functional land use forms and woodland structures – each characterised by its own floristic make-up – is comparatively high. In contrast, in regions with less population but that were settled at a later date, one encounters fewer stands of woody plants with lower numbers of species. This revised version was published online in June 2006 with corrections to the Cover Date.     

Retention of aspen (Populus tremulae) at final cuttings - The effect of dead wood characteristics on saproxylic beetles

To preserve biodiversity in managed forest landscapes dead and living trees are retained at final cuttings. In the present study we evaluated the effect of these practices for saproxylic (wood-dependent) beetles inhabiting dead aspen trees (Populus tremulae). For saproxylic beetles, tree retention at final cuttings can be expected to be especially valuable for species adapted to sun-exposed dead wood, a substrate that only rarely occurs in well managed forest stands. Therefore, the current evaluation was conducted as a comparison of species richness, species density (number of species per sample), assemblage composition and occurrence of individual species between clear-cuts, where aspen trees were retained, and closed forest stands with aspen trees. The study was conducted in central Sweden and the beetles were sampled by sieving of bark from CWD (coarse woody debris) of aspen. There was no significant difference in rarefied species richness between forest and clear-cut sites. Species composition differed significantly between the two stand types. Generalized linear mixed-effects models predicted the species density to be 34% lower in CWD objects in forest sites than on clear-cuts. This pattern could partly be explained by differences in CWD diameter, decay class and bark types between the two stand types (clear-cut/forest). Stand type was a significant predictor of occurrence in individual CWD objects for 30% of analysed individual beetle species. For all species except one, the variable stand type predicted higher occurrence on clear-cuts than in forest stands. To conclude, our results demonstrate that retention of aspen on clear-cuts contributes to population recruitment of a different assemblage of species than CWD within stands.     

基于“生态相似性”的珍稀濒危物种植物营养保育策略(英文)

中国主要植物园目前正开展大规模的珍稀濒危植物迁地保护工作,但业已存在和可预见的生长繁殖障碍问题在迁地保护过程中往往被忽视。本文针对这一现状,提出了"基于‘生态相似性’的珍稀濒危物种迁地保护植物营养保育策略"。其主要思路是:迁地保护物种来自于自然生态系统,被人为安置在人工生态系统,最终它们将回归自然生态系统。因此,对于迁地保护物种的植物营养学研究,一方面应该有别于人工生态系统中的以追求产量与品质为主,另一方面也不能只停留在研究其固有的自然规律而排斥人为干预。我们必须兼顾其在自然生态系统与人工生态系统的双重属性,即依据"生态相似性"原理,充分运用人工生态系统中的植物营养学研究手段解决存在的实际问题,以保证物种最终回归大自然并发挥其应有的生态功能。参69。     

北京市朝阳区景观连接度距离阈值研究

景观连接度方法是一种进行景观生态安全格局定量化评价的较好方法。此方法的应用中,景观连接度适宜距离阈值是一个关键因素,以北京市朝阳区为例对其展开研究。选取景观组分数(NC)、整体连接度指数(ⅡC)以及可能连接度指数(PC)来表征景观连接度以及计算斑块重要性值(dI);预设9个距离阈值,探讨不同距离阈值下景观连接度和斑块重要性值的变化规律。结果表明:北京市朝阳区景观连接度的距离阈值以400～600 m为宜。在此距离阈值的约束下分析表明,小型生态斑块对提高区域景观连接度有重要作用。     

加工活性炭处理松材线虫病死木技术的研究

经３ａ的试验和实践结果表明，加工活性炭处理松材线虫病死木中松褐天牛成、幼虫等媒介昆虫是一项简单易行、灭害彻底、效益较高的处理松材线虫病死木的新技术，值得在疫区推广应用。     

Effects of physical properties of wood on the water activity of wood meal media for the cultivation of edible mushrooms

The effects of physical properties of wood, including specific gravity, porosity, and water retention, on the water activity (a _w) of wood meal media for the cultivation of edible mushrooms were examined. Five species of wood, selected from an initial set of 11 species, and six species of fungi popularly cultivated in Japan were used. The water activity of each fungal species was measured using liquid media in which a _w had been reduced by adding NaCl, KCl, sucrose, or ethylene glycol. From the water activities of the media and fungi, we estimated the most suitable wood species for the cultivation of each edible mushroom in wood meal media. Suitable wood species for the wood meal cultivation of shiitake, nameko, and maitake, which had relatively high a _w, was limited to hardwoods like arakashi, konara, and irohakaede because of their higher water activities. Edible mushrooms with lower levels of a _w, like hiratake, enokitake, and bunashimeji, could be cultivated in all kinds of wood species used in this experiment, but especially in sugi.Parts of this report were presented at the 49th, 50th, 51st, and 52nd Annual Meetings of the Japan Wood Research Society, in Kyoto (April 2000), Tokyo (April 2001), Gifu (April 2002), and Fukuoka (March 2003), Japan     

Effects of wood species on degradation rates and bacterial communities in a small-scale biodegradation system for garbage using wood matrices

Simulated organic waste was biodegraded in a laboratory-scale machine using matrices prepared from four wood species to investigate the effects of wood species on the degradation rate and the bacterial community. The degradation rate, estimated by measuring weight loss and CO₂ evolution, was found to be equal among the four wood species. Changes in viable cell counts and microbial communities over time were examined. Viable cell counts were also similar among the wood species, but initial bacterial communities differed owing to differences in wood species, although these communities became similar with time. The sensitivity of isolates to wood extractives was examined using paper discs. The extractive-insensitive bacteria species were dominant at the initial stage of biodegradation. However, occupancy of sensitive bacteria increased with time. It was thought that antibacterial extractives were degraded or inactivated after some time.Part of this report was presented at the 50th annual meeting of the Japan Wood Research Society, Kyoto. Japan, April 2000     

基于时延神经网络的木材干燥温湿度建模研究

利用神经网络建立了木材干燥的温湿度模型,给出了其时延神经网络辨识结构。分别提出温、湿度控制模型(控制信号与温、湿度之间的关系模型)和木材干燥基准模型(温、湿度与木材含水率之间的关系模型),并利用实验干燥窑得到的实际数据进行了仿真研究。仿真结果表明,利用此方法建模是可行的,所建模型是有效的。图10参16。     

A simulation study on the effects of plot size and shape on sampling plant species composition for biodiversity management

Sustainable management of plant diversity in a forest requires adequate information that is often derived from samples. With limited resources, the plot design has to be efficient. Most studies focused on evaluating effects of plot designs on sample estimates of species richness at landscape scale. This study aims at filling a knowledge gap by investigating how plot size and shape affect sample estimates of species composition at a local scale. Two census datasets with distinct forest ecosystems were used. Fifteen combinations of plot size and shape were simulated. Species compositional similarity between two combinations of plot design at a sample point was estimated by Jaccard and Sørensen indices, and their abundance-adjusted counterparts. Similarity in species composition decreased with increasing difference between two plot sizes. Plots with varying shapes were found to have different local species composition but could be similar in the number of observed species, which has not been explicitly reported elsewhere. For less species-rich forests, a 0.025–0.05 ha circular plot is recommended. For species-rich forests, a 0.05–0.1 ha rectangular plot with aspect ratio of at least 1:20 is recommended. The results should be of interest to stakeholders managing small area forests for conservation of plant diversity.     

The effects of shade on the plant communities of rides in plantation woodland and implications for butterfly conservation

During 1985-6 the vegetation in the rides (forest tracks) of eight English lowland woods, planted on ancient woodland sites was surveyed. Shade was measured in each transect by hemispherical photography. Dicotyledonous species richness and the majority of dicot plant species declined as shade increased. The results for individual species compare favourably with Ellenberg's (L) value in most cases, and a method is suggested for modifying Ellenberg's data in the light of new information. The woodlands contained species of both open and shaded habitats and communities were influenced by soil acidity. Because shade in woodland rides increases as the trees mature, theory states that there will almost certainly be a reduction in plant species diversity. Butterfly populations would also be adversely affected, partly because of the reduction in direct sunlight, and partly because their larval foodplants decline in both quantity and quality since they are generally associated with low to moderate shade.     

秃极种质资源迁地保存栽培技术的研究

通过江苏省10年来秃杉种质资源迁地保存利用及相关栽培技术的研究结果表明，在江苏成功引种需采用“选择山洼、北坡或大型河堤有侧方林带庇荫的土层深厚、疏松、湿润的立地条件，用健壮2年生裸根苗或容器苗或带土苗于2月中旬至3月上旬栽植，实行针阔混交侧方遮荫或疏林复层混交遮荫，林地间作豆类等作物覆盖保湿，年生长速生期前（5月中旬-6月中旬）增施氮肥或氮钾复合肥，促进生长”等综合栽培技术。文内还结合引种保存区的自然条件和应用目的，提出了适合苏南低山丘陵山地、自然保护区、森林公园、苏北平原大型河堤，以及城镇绿化的多种栽植模式。     

秃杉种质资源迁地保存育苗技术研究

总结研究了13a来在地处亚热带在江苏省宁镇丘陵地区引种原产云贵高原、鄂西山地的珍稀树种秃杉获得在播种育苗与无性繁殖技术成果。该项 成果认为采用氧化剂消毒浸种侵芽,适时防治幼苗猝倒病,适度遮荫保湿,当年冬季防寒保苗等组装技术,可使每公斤种子产秃杉合格苗2．20万－5．60万株,1年生苗安全越冬;采用砻糠灰作基质,用KMnO4液浸条,在秋冬季扦插,生根率达41．3％－54．4％;用电子叶间隙喷雾,以珍珠岩作基质,或在日光温室内用塑料薄膜封闭保温,用KMnO4液浸条等技术,可使插条生根率达72．6％和76．1％。     

干旱河谷10种生态恢复树种的光合和水分生理特征研究

通过对岷江上游干旱河谷10种生态恢复树种盆栽苗木的光合、荧光以及水分生理特征等的比较,分析了不同植物在干旱地区的光合运作情况以及光合生理特征和水分生理特征,及其间的相关关系,揭示了各类植物的抗旱特征,以期为干旱河谷区植被恢复树种材料的选择提供理论依据。     

武都县洛塘林区自然保护价值生态评价的初步研究

通过数量化分析方法，对甘肃陇南地区武都肥洛塘天然林区进行了自然保护价值生态评价。初步评价结果为87.9分，这在国内国家级自然保护区中处于前列，说明这一区域具有重要的保护地位，亟待建立自然保护区，予以重点保护。同时提出区域发展对策，为管理决策和制定规划提供理论依据。     

基于隶属函数的杉木伴生树种的选择

根据生态相似度,采用隶属函数方法对6种不同类型的杉木伴生树种的选择开展分析,结果表明：木荷和毛竹是良好的杉木伴生树种,马尾松和虎皮楠是较好的伴生树种,而猴欢喜和厚皮香是较差的伴生树种。     

基于生态位模型的松材线虫潜在生境预测方法研究

以江苏省松材线虫（Bursaphelenchus xylophilus）定点发生数据和31个环境变量为主要信息源,采用分类与回归树模型（CART）、基于规则的遗传算法（GARP）、最大熵法（Maxent）、逻辑斯蒂回归（LR）4种模型建立松材线虫在江苏省的潜在生境预测模型,从接受者曲线下面积（AUC）、Pearson相关系数、Kappa值3个方面来检验模型预测精度,分析松材线虫的空间分布规律及其环境影响因素.研究结果表明：在3个评价指标中,CART模型的预测精度较低,其它3个模型的预测精度均达到优良水平,其中Maxent在物种现实生境模拟、主要生态环境因子筛选、环境因子对物种生境影响的定量描述方面都表现出优越的性能.GARP模型对松材线虫潜在生境的预测方面表现出优越的性能.海拔、年降水量、降水的季节性变化、温度的年变化范围是影响松材线虫空间分布的主要环境因子.     

A decision support tool approach based on the Electre TRI-B method for the valorisation of tropical timbers from the Congo Basin: an application for glulam products

An alternative approach to the formal management strategy of tropical timber species from the Congo Basin was investigated. It focused on the development of glulam, with an aim to specify a decision support model for the valorisation of tropical timber species considered for use in these products. There were 76 forest species analysed regarding ecological, engineering and social criteria according to their major uses. The Electre TRI-B multicriteria sorting method was used. The main result was a new and robust classification tool of timber species from the Congo Basin, corresponding to their multicriteria consensus degree. The potentials of the new grouping system were analysed. Species that meet a great majority of criteria were identified. They were highly suitable for sustaining the market position of glulam products. Implementing this strategy may significantly improve the management and increase the value of the timber species from the Congo Basin, while preserving endangered species.