共查询到20条相似文献，搜索用时 62 毫秒
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乳源木莲杉木混交林生长及其竞争关系分析 总被引：6，自引：0，他引：6
阔叶林尤其是常绿阔叶林是亚热带地区的地带性植被,它的存在对维护我国广大南方地域的生态平衡、满足经济建设和人民生活需要起着极其重要的作用。但近年来,阔叶林的人为破坏及阔叶树种人工培育不受重视,加上发展针叶人工林,致使针阔比例严重失调,产生一系列生态问题,很多优良乡土阔叶树种随着天然林的肆意砍伐利用而逐步消失(盛炜彤,1993;俞新妥,1997;陈存及等,2000)。为了扭转这种局面,福建省近年来开始重视阔叶树种的造林,大力挖掘优良乡土树种和寻找新树种,特别是珍稀速生阔叶树种。但是很多优良乡土树种连采种育苗都极为困难,乳源木莲… 相似文献
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南酸枣优树选择方法及优树子代苗期性状变异 总被引：3，自引：0，他引：3
随着我国南方林区树种、林种结构的调整 ,以及市场对阔叶材 ,特别是优质装饰阔叶材的需求逐年增加 ,主要造林树种已从以针叶树种松、杉造林为主 ,逐步转为针阔叶树种并重的格局 ,并向定向、集约化方向发展。近几年来 ,阔叶树造林面积不断扩大 ,绝大部分是以当地普通种为主 ,有些树种采种很困难。可是当前对阔叶树、特别是优质阔叶树种的地理种源变异、遗传改良、育苗造林技术等研究相对较薄弱 ,滞后于生产。南酸枣 (ＣｈｏｅｒｏｓｐｏｎｄｉａｓａｘｉｌｌａｒｉｓＢｕｒｔｔ.ｅｔＨｉｌｌ) ,又称酸枣、五眼果等 ,属漆树科落叶阔叶乔木树种… 相似文献
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在广东乐昌龙山林场进行山乌桕等43个乡土阔叶树种山地造林对比试验,4年生结果显示,43个树种间的造林成活率、树高、胸径、冠幅生长量均存在极显著差异,表明北江流域山地造林成功的技术关键之一是树种选择.43种乡土阔叶树种的高生长与胸径(地径)生长均表现出极显著的正相关(P＜0.000 1).根据各树种的造林成活率与生长量的综合表现,山乌桕、黎蒴、冬桃杜英、枫香、山杜英、拟赤杨、网脉山龙眼、石栎、荷木、杨梅、拐枣在北江流域山地造林表现较优,可作为当地营造水土保持林、水源涵养林等生态公益林的首选树种. 相似文献
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随着我国社会经济的发展,逐步暴露出了许多的生态环境问题。而为了维持生态的平衡,就要提高植树造林的力度,这其中碳汇造林就是植树造林工作的延伸。在碳汇造林中乡土阔叶树种发挥着重要作用,针对乡土阔叶树种在碳汇造林中的应用进行分析,对项目中出现的问题进行优化。 相似文献
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三峡地区高山乡土造林树种选择研究 总被引：2，自引：0，他引：2
《湖北林业科技》2012,(6)
自上世纪70年代以来,大老岭林场开展了北亚热带三峡地区高山造林树种生态调查[1]。依据调查结果:1981年选择玉兰、银鹊、鹅掌秋、鄂枫杨、漆树、大叶杨、山桐子、桦榛、白辛、檫木、珙桐、香椿、亮叶桦、水曲柳等阔叶乡土树种和油松、华山松、落叶松、柳杉等针叶乡土树种开展栽培试验研究。通过各树种成活率、保存率及生长量26 a(2004)调查表明:26 a(2004)生现实遗传增益银鹊比11个阔叶树种材积提高26.8%,比其它10个阔叶树种材积提高32.0%;日本柳杉比4个针叶树种材积提高36.5%,比其它3个针叶树种材积提高48.8%。银鹊,日本柳杉最适宜三峡山区生长,营造银鹊、日本柳杉工业用材林,可大力提高新造林分生产力,现实遗传增益15%以上,取得较好的经济、社会和生态效益。 相似文献
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通过对鄂尔多斯7种不同种源主要绿化树种胸径(地茎)、树高、冠幅、新生枝长的观测,以及多指标综合分析,以确定每一树种的最佳种源地。研究结果表明,乡土树种和在本地引种驯化多年的树种均表现为本地种源适应性最强,生长表现最好;外来引进树种表现为由自然条件较差地区向自然条件较好地区引进适应性较强,生长表现较好。建议鄂尔多斯市在以后的绿化过程中,要注重推广应用乡土树种和引种驯化多年的树种;而在引进外来树种时,要坚持从相应的种子区(亚区)或相邻的种子区(亚区),以及从自然条件低于鄂尔多斯市的地区选购。 相似文献
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通过对福建省乡土野生绿化树种调查,筛选出园林观赏价值高、经济效益好的福建山樱花、香港四照花等10种乡土野生绿化树种进行驯化栽培试验,总结出栽培配套技术和3年生各树种生长情况,投入产出比达1∶3~1∶13,获得显著社会、生态和经济效益,为园林规划和林业生产提供科学依据。 相似文献
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东莞大岭山村边自然次生林群落物种组成特征及其对区域物种库的贡献 总被引：9，自引：2，他引：7
对东莞大岭山村边自然次生林（俗称“风水林”）调查表明,群落组成种类复杂并富于热带性,1hm^2样地内共有维管束植物111种,隶属56科89属,其中以木本植物占绝对优势,有67种,占60．36％;群落中种子植物属为热带分布的共有74属,占总属数的92．5％。群落乔木可分三层,以越南山龙眼为主,其在各层的重要值分别为117．12％,129．44％和57．41％;灌木层以罗伞树和九节等为主;草本层植物以乔灌木小苗为主,草本植物仅沿阶草、海芋和半边旗等少数种类。群落木本植物的科、属、种对区域物种库的贡献率较大,分别为37．7％,25．6％和22．5％,以藤本植物的贡献率最高,接近50％,乔灌植物的贡献率也在20％左右．与鼎湖山季风常绿阔叶林比较．两者物种组成结构相似．但组成种娄仍有一定差距． 相似文献
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Many boreal tree stands are neither clearly even-aged nor clearly uneven-aged. The stands may undergo a series of stages, during which an even-aged stand is transformed into two-storied mixed stand, and finally to multistoried or uneven-aged stand structure. The species composition often changes during the succession of stand stages. This study developed models for stand dynamics that can be used in different stand structures and species compositions. The model set consists of species-specific individual-tree diameter increment and survival models, and models for ingrowth. Separate models were developed for Scots pine, Norway spruce, and hardwood species. The models were used in a growth simulator, to give illustrative examples on species influences and stand dynamics. Methods to simulate residual variation around diameter increment and ingrowth models are also presented. The results suggest that mixed stands are more productive than one-species stands. Spruce in particular benefits from an admixture of other species. Mixed species improve diameter increment, decrease mortality, and increase ingrowth. Pine is a more beneficial admixture than birch. Simulations showed that uneven-aged management of spruce forests is sustainable and productive, and even-aged conifer stands growing on medium sites can be converted into uneven-aged mixed stands by a series of strong high thinnings. 相似文献
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植物引种与外来物种入侵的探讨 总被引：7，自引：0，他引：7
生物入侵正在成为影响我国生态系统的重要因素之一。外来生物入侵的问题 ,越来越受到全社会的关注。本文主要分析了我国外来入侵植物的现状 ,如外来入侵植物的主要种类、对我国生态环境的危害、主要传入途径以及监控措施。 相似文献
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Reforestation, particularly in the tropics, is of crucial importance for the environment as well as society. However, small planting areas and low participation of smallholder farmers in tree planting programmes often obstruct realisation of set planting area targets. In this regard, we interviewed smallholder farmers undertaking indigenous species reforestation in Oda Kotoamso community within the Wassa Amenfi West District in Western Region of Ghana with a pre-tested questionnaire to identify (1) key socio-economic factors that predict the size of plantations they establish, (2) options that could encourage tree planting among smallholder farmers, and (3) tree species planted by the smallholder farmers and their conservation status according to the IUCN Red List of Threatened Species. Key socio-economic factors were predicted with multiple regression models and ANOVA. Options were ranked on a five-point Likert scale and their differences were tested with the Mann–Whitney U test. Age and income of smallholders are the significant predictors of plantation sizes but farmers’ household size and gender were not significant. Age and income accounted for 77.1% and 22.9%, respectively, of the total variation described by our model (R?2 = 38.4%). In order of importance, incentives (mean = 4.35, SD = 0.48), public nurseries (mean = 4.2, SD = 0.82) and agroforestry (mean = 4.06, SD = 0.56) were the options that could encourage reforestation, though incentives and public nurseries were not significantly different (p > 0.05). Almost half (9 of 19) of the tree species planted are categorised as Vulnerable species, which highlights the contribution of smallholder farmers to recovery of threatened tree species. Our findings suggest that sustainable provision of planting materials in incentivised and youth-based tree planting programmes could increase planting hectarage and conserve threatened tree species. 相似文献
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在对重庆市的自然条件及社会经济状况分析的基础上,对实地调查和通过资料查阅确定的60种重庆市优良乡土树种进行了综合评价及选择。分别依据不同用途的树种制定不同的选择标准,确定出若干评价指标：对用材树种选定了速生性、丰产性、耐瘠性、抗寒性、抗旱性、抗病虫害能力、干材形质、材用价值等8个指标;对生物质能源树种选定了速生性、丰产性、耐瘠性、抗寒性、抗旱性、抗病虫害能力、多用途性、工业价值等8个指标;对景观树种选定了观叶、观花、观果、观树形、抗寒性、抗旱性、抗病虫害能力、抗污染性、吸硫能力、滞尘能力、降低噪音能力等11个指标。采用3分制并提出了每个指标的分级标准,运用层次分析法来确定各个指标的权重,根据各指标的分值和权重对60个目标树种进行了综合评价。主要结果与结论如下：（1）对20种用材树种进行综合评价的结果表明：鹅掌楸、香椿、桤木、檫木、毛桂、香樟为综合效益较高的用材树种,苦楝、川楝、厚朴、山杜英等树种次之。（2）按照20种生物质能源树种的综合评价值大小,建议选择杜仲、桤木、苦楝、刺槐、光皮树、山桐子等树种作为生物质能源林建设的主要树种。此外,灯台树、山苍子、文冠果、麻栎、栓皮栎等可以作为备选树种。（3）通过对20种景观树种的综合评价分析得出,深山含笑、四照花、珙桐、栾树、枫香、厚朴等是非常优异的观赏树种,可作为绿化骨干树种,枫杨、山桐子、红豆树、伯乐树等可作为绿化基调树种。 相似文献
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《Journal of Sustainable Forestry》2013,32(2-3):223-236
Abstract Conservation organizations in the Condor Bioreserve (CBR) in northern Ecuador use the spectacled bear (Tremarctos ornatus) as a surrogate species to focus conservation efforts. However, the utility of single-species management has been questioned in recent scientific literature, making it appropriate to review the spectacled bear's efficacy as a conservation tool. The spectacled bear does not enjoy unqualified public support in CBR and surroundings, suggesting that it may not be appropriate as a flagship species. It may be more effective as a keystone species; its diet and migratory habits suggest that it may have a significant impact on plant community structure through fruit dispersal. However, more research is needed in this arena before drawing any conclusions. The spectacled bear is perhaps most appropriate as an umbrella species because of its large home range, which encompasses at least two ecosystem types: páramo and montane forest. Traditionally, the concept of the umbrella species has stressed minimum area requirements, but the spectacled bear may be a more effective umbrella species if its dispersal requirements and seasonal migration patterns are also addressed. Eco-Ciencia, an Ecuadorian research organization, recently constructed a habitat model for spectacled bear. They are uniquely positioned to address issues of habitat connectivity both within and between the protected areas of CBR. In doing so, they could influence future zoning decisions in and around CBR, an area that is experiencing rapid population growth. This could improve conservation efforts for spectacled bear and other species. 相似文献