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广东东莞短萼仪花的资源分布与观赏特性研究 总被引：2，自引：1，他引：1
短萼仪花(Lysidice brevicalyx C. F. Wei)属苏木科仪花属,是我国特有的少见植物,株型挺拔、叶密而翠绿、花色艳丽、花期长,是优良的乡土园林树种,目前对其研究报道非常少。在广东东莞,短萼仪花只分布于清溪林场,主要以单株散生、萌生林2种群落类型存在,面积46.7 hm2,为目前广东省范围内最大面积的短萼仪花群落。文章报道了短萼仪花在东莞的资源现状与观赏特性,研究了短萼仪花的开花结实特性及种子萌发规律,提出了建立短萼仪花保护点,扩大异地繁育栽培面积,进行种质资源的有效保护措施和资源的持续利用对策。 相似文献
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广东五桂山四药门花种群生态学研究 总被引：4，自引：2，他引：2
四药门花（Loropetalum subcordatum）是我国特有的稀有植物,仅零星分布在香港、广东和广西。中山五桂山是四药门花自然种群的主要栖息地之一。在五桂山四药门花种群所在的次生林群落中设置样方,调查样方内树种名称及其胸径和树高;采取相邻格子法,记录样方内所有四药门花植株及其大小。调查结果表明四药门花所在的次生林群落以降真香（Acronychia pedunculata）、四药门花和铁榄（Sinosideroxylonwightianum）等树种为优势。在400 m2的样方中,乔木层树种丰富度指数为2.10～4.08,灌木层为5.81～8.37;乔木层Shannon-W iener多样性指数为1.42～2.51,灌木层为2.78～3.89;乔木层树种均匀度指数为0.59～0.84,灌木层为0.81～0.92。种群调查结果表明四药门花种群小,以Ⅲ级小树（2.5 cm≤dbh≤7.5cm）为优势,缺乏幼苗和幼树,自然更新不良;四药门花花期长,但自然种群的结实率低。继续开展四药门花自然种群的传粉生物学、遗传多样性和种苗扩繁技术研究有利于该稀有物种资源的保护和利用。 相似文献
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对宁波市鄞州区天童林场盘山林区退化金钱松人工林实施择伐、留养和补植先锋树种的近自然化改造,比较不同林分早期恢复生长的差异。结果表明:①改造6年后,山坡上的木荷、青冈和沟谷上的红楠等地带性常绿阔叶树种呈快速的恢复生长,已形成了一个高3~5 m的更新层,林分结构得到改善,已形成松阔异龄混交林,比对照区林分蓄积量分别提高68.3%和18.9%。②通过抚育使山坡和沟谷类型更新层的优势种群密度分别达2 538、3 183株.hm-2,比对照区提高1.8倍、7.2倍;山坡类型更新的木荷和青冈种群的个体数量分布基本上呈正态分布,这表明更新种群都处于恢复中前期增长进程阶段;沟谷类型更新的红楠种群个体数量呈逆J型分布,已成为稳定型种群。③改造后混交林群落结构发生变化,更新优势种群抗胁迫性显著增强。 相似文献
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珠海市是广东省最早建立的经济特区之一。由于长期的人类活动,珠海市原生森林早已破坏殆尽,现有的山地森林群落多为人工林和次生植被。应用样方法,在珠海面积较大、林相结构较完整的森林群落中设置了34个面积400m2的样方,调查和分析了这些山地森林群落的物种组成和植物多样性特点。研究结果表明,珠海市山地森林群落类型主要有风水林、沟谷林和早期次生林,以风水林和沟谷林的物种多样性较高,它们是珠海市宝贵的森林遗产。珠海市的森林群落以樟科、大戟科和山茶科植物最为丰富,茜草科、桃金娘科和桑科等热带植物种类也比较丰富。珠海市的天然林对维持当地生态平衡和区域性生物多样性的保护均具有重要的作用。 相似文献
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《林业实用技术》2018,(12)
为了解江西五梅山自然保护区药用树种虎皮楠(Daphniphyllum oldhamii)群落的分布和生长情况,采用样方调查法,在虎皮楠自然集中分布的区域设置样方并开展全面调查,研究结果表明:(1)虎皮楠群落中共有维管束植物62种,隶属31科53属。植物区系组成以北温带分布和热带亚洲分布占比最高;(2)群落的垂直结构可分为乔木层、灌木层和草本层,乔木层较草本层和灌木层发达。群落根据Raunkiaer生活型谱划分,居于第一的是高位芽植物,占79. 03%;(3)群落中虎皮楠的重要值为17. 58,为该群落的优势种;多样性指数(H)灌木层最高,均匀度指数乔木层最高;物种丰富度灌木层最高;(4)年龄结构显示,江西五梅山自然保护区虎皮楠正处于年轻茂盛的阶段,种群比较稳定。 相似文献
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基于40个样方的调查数据,明确乔木层径级分布和物种类型,揭示种群特征和种间关联性,分析孔林植物群落物种多样性,评价植物群落恢复现状和演替动态。结果表明:1)乔木层和灌木层的Shannon-Wiener指数、Simpson指数和Pielou指数为黄连木群落显著高于侧柏群落(P<0.05),与麻栎群落无显著差异,其草本层间各多样性指数均无显著性差异;2)乔木扩展种7种、隐退种16种、稳定侵入种2种和随机侵入种3种,侧柏种群明显缺乏Ⅰ级幼苗和Ⅱ级幼树,麻栎种群极度缺乏Ⅱ级幼树;3)造成当前孔林植被现状的主要因素是灌草收割试验,重要原因是景观破碎化、面积效应和环境非异质性。 相似文献
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Philip M. Perrin Fraser J.G. MitchellDaniel L. Kelly 《Forest Ecology and Management》2011,262(12):2328-2337
Changes in ground flora were monitored over a 32-year period in deer exclosures in a yew-wood and a neighbouring oakwood in Killarney National Park, southwest Ireland; both woods are Annex I habitats under the European Habitats Directive. Comparison was made with unfenced plots adjacent to each of the exclosures. During the period of the study, both woods were heavily grazed by introduced sika deer (Cervus nippon). In the yew-wood exclosures, total ground flora cover increased markedly during the period of deer exclusion, the main species to increase in abundance being Rubus fruticosus agg. and Hedera helix. Herbaceous species increased initially in frequency but subsequently declined; herbaceous species had higher total cover in unfenced plots than in fenced plots at the end of the study. In the oakwood, Luzula sylvatica and Vaccinium myrtillus expanded their cover in one exclosure with cover in ferns declining, but in other exclosures where dense holly thickets developed, it was instead R. fruticosus and H. helix that became more abundant within the fences than outside. Overall, long-term fencing has caused a shift from vegetation characterised by woodland specialist to woodland generalist species and there are indications of a long-term decline in diversity. We conclude that chronic heavy grazing in these woodlands has strongly influenced the overall abundance and composition of the ground flora, but that complete exclusion of grazing is also undesirable due to potential declines in diversity of woodland specialists. 相似文献
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研究合肥市区不同功能区景观林组成与结构,共记录102个样方。结果表明:景观林主要组成种有111种,分属45科、81属;主要优势种是香樟、枫杨、水杉、杨树、桂花、石楠等;不同功能区景观林树种相似性系数分别为0.4(公园与居住区)、0.24(高校与居住区)、0.22(公园与高校);林分平均密度560株/hm2,平均基盖度18.83 m2/hm2,平均胸径16.99 cm,平均树高10.13 m,均为正态分布。群落类型可归纳为5个植被型、16个群系及69个群丛,以落叶阔叶型与常绿落叶阔叶混交型为主。建群树种主要有香樟、广玉兰、女贞、雪松、水杉;群落外貌较整齐,树木整体较为健康,景观效果较佳;但层次结构、树种多样性不高,应丰富树种,增加群落的垂直层次,采用近自然经营。
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《Forest Ecology and Management》1999,113(1):11-21
A methodological approach to the identification of biodiversity indicators in commercial forest stands is illustrated by analysis of the relationships between syrphid (hoverflies) and carabid (ground beetles) community composition and diversity, and stand structure and field layer vegetation. Data were collected from 12 commercial forest sites encompassing a range of climatic conditions and different crop types (Scots pine, Sitka spruce, Norway spruce and Corsican pine) across the UK. Comparisons were also made between unmanaged semi-natural Scots pine woods and Scots pine plantations. For both syrphids and carabids, no differences in species richness and diversity were recorded between semi-natural stands and plantations; one rare syrphid considered to be restricted to semi-natural pine stands was also found in spruce. Syrphid species diversity and richness was higher in southern spruce sites than in the northern sites. Northern sites had distinctive carabid communities, as did sites in the New Forest, a large ancient woodland in southern England. Of the measured habitat variables, vertical stand structure showed the best correlation with species richness and diversity of both carabids and syrphids. Richness and diversity were less in stands with high vertical cover values for canopy layers. Stands with higher field layer cover supported greater syrphid diversity, but lower carabid diversity. Measures of stand structure could be used as potential indicators of syrphid and carabid diversity, but additional habitat parameters also need to be tested. 相似文献
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不同林分类型及土层对土壤养分的影响 总被引：2，自引：0，他引：2
在中山五桂山保护区选择4个不同的林分类型,分别进行土壤采样,测定土壤养分指标,分析不同林分类型及土层对土壤养分的影响,为林分改造、土壤养分改良提供理论和数据支撑。结果表明:(1)四种土壤养分指标在四种林分类型间均有显著性差异,四种林分类型的土壤养分指标含量大小排序大致为:沟谷季雨林阔叶混针阔混针叶林,只有有效磷含量是阔叶混大于沟谷季雨林。(2)四种土壤养分指标在针叶林、针阔混交林、沟谷季雨林这3种林型中的5个土层间变化均有显著性差异,而在常绿阔叶林中仅速效钾在5个土层间有显著性差异。(3)四种林分类型中,沟谷季雨林各指标含量相对较高,处于"中下"等级,而针叶林各指标含量低,处于"很低"等级。总的来说,四种林分类型的土壤养分含量偏低,特别是针叶林,各项土壤指标含量均为"很低",可以参考群落演替方向对针叶林进行林分改造来提高土壤养分。 相似文献
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《Southern Forests》2013,75(2):113-117
The study investigated the tree species composition, vegetation structure and harvesting pattern to guide management of the Maruzi Hills Forest Reserve. Stratified random sampling was used to site six (100 m × 100 m) permanent sample plots in the woodland, bushland and grassland vegetation types identified in the reserve. Rényi diversity profiles indicated that bushland vegetation had a lower Shannon diversity index (H = 2.054) than grassland (H = 2.38) and woodland vegetation (H = 2.319). Grassland and woodland vegetation also had lower proportions of the dominant species (α∞ = 1.15 and 1.66, respectively) than bushland vegetation (α∞ = 3.25). However, the mean stem density of the woodland, bushland and grassland vegetation was 214 stems ha?1, 191 stems ha?1 and 114 stems ha?1, respectively. Bray-Curtis and Jaccard ecological distance matrices showed that, although the three vegetation types shared some common species, the ecological distances were relatively high suggesting significant species composition variation between the vegetation types, particularly between the bushland and the other vegetation types. The species with the highest proportional abundance in the survey were Combretum molle (23%), Acacia hockii (17.7%), Combretum collinum (16.1%), Grewia mollis (6.5%) and Lannea barteri (6.5%). Diameter size-class distribution of woody perennials and tree stumps indicated higher frequencies of the smaller-diameter size classes. The stump records were indicative of charcoal burning and firewood collection as major causes of tree/shrub harvesting. The Maruzi Hills woodland conservation strategy should consider the differences in species composition between vegetation types if the highest number of species is to be conserved. 相似文献
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两种菊酯类农药对马尾松林昆虫群落的影响 总被引：7，自引：0，他引：7
化学农药的大量使用,会导致许多不良后果,如害虫的抗药性增加,次要害虫的爆发,对非目标生物的不良影响,农药残毒对环境的污染等等。但由于化防具有高效、快速、方便、灵活和经济等特点,如何利用生态学原理恰当应用农药,使它在害虫综合管理中发挥作用,是一个重要的研究课题。作者于1989年4月-1990年4月,对马尾松林昆虫群落(包括蜘蛛)化防前后的种类和数量变化进行了连续的抽样调查,旨在分析菊酯类农药对群落的影响程度,对如何评价菊酯类农药防治对昆虫群落的影响和指导害虫防治提供依据。 相似文献
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甜槠林是我国中亚热带地区地带性植被常绿阔叶林的主要类型之一,也是鹰咀界天然林保护区内代表性植被。我们在群落调查的基础上,通过统计计算分析将区内的甜槠林分成3大类别8种群落类型。并分别用物种丰富度指数（Dg1）、Simpson指数（D）、Shannon—Wiener指数（H’）、Pielou均匀度指数（J）、Alatalo均匀度指数（E）对各群落类型进行了物种多样性研究,结论为：群落多样性乔木层、灌木层（不包括乔木幼树、幼苗）〉草本层,但乔木层多样性不一定大于灌木层,灌木层、草本层的分布均匀度较乔木层高,变异系数小。 相似文献
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The Impact of Large Herbivores on the Conservation of Semi-natural Woods in the British Uplands 总被引：3，自引：0，他引：3
This review considers the history of woodland grazing and thegrazing ecology of large herbivores in the context of the conservationof semi-natural woods in the British uplands. The impact thatgrazing has on natural regeneration is frequently highlightedbut its effects on other vegetation, particularly the balancebetween bryophytes and higher plants are equally important.Grazing also influences both invertebrate and vertebrate populationsthrough its effect on vegetation structure. A low level of grazingby large herbivores in woodland provides a greater diversityin vegetation structure and species composition than eitherthe current prevalence of overgrazing or the absence of grazingin fenced woods. Low levels of grazing may also create conditionsfor the highest diversity of both plants and animals. The practicalproblems of managing woodland grazing are addressed in relationto conservation objectives for upland woods. Rotational grazing,seasonal grazing and reducing the overall levels of grazingin a wood are identified as possible management options. Furtherwork on these is however needed and topics for future researchare identified. 相似文献