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以平潭岛天然次生林为研究对象,分析灌草丛、针叶林、针叶混交林、常绿阔叶林群落的物种组成、重要值、物种多样性特征的变化,探讨平潭岛与邻近海岛和大陆的群落物种多样性差异。结果表明:4种群落类型共有53科89属104种植物,群落类型间及各层次的丰富度、多样性、均匀度从灌草丛到针阔混交林阶段呈上升趋势,阔叶林阶段呈下降趋势。群落各层次的丰富度、多样性变化,乔木层为针阔混交林>阔叶林>针叶林;灌木层为针阔混交林>针叶林>常绿阔叶林>灌草丛;草本层为针阔混交林>常绿阔叶林>针叶林>灌草丛。单因素方差分析,乔木层丰富度、多样性、均匀度在针阔混交林和针叶林呈显著性差异(P<0.05);灌木层和草本层多样性在针阔混交林与灌草丛和常绿阔叶林呈显著性差异(P<0.05)。平潭岛群落物种多样性水平明显低于普陀山岛和大陆。 相似文献
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卧龙自然保护区大熊猫栖息地植物群落多样性研究:丰富度、物种多样性指数和均匀度 总被引：2，自引：0，他引：2
根据64个植被样方调查资料,分析卧龙自然保护区大熊猫栖息地植物群落多样性特征.结果表明:卧龙自然保护区大熊猫栖息地不同植被类型的物种多样性指数值H'、D和均匀度指数Jsi基本表现出一致的变化趋势:常绿落叶阔叶林＞温性针阔混交林＞落叶阔叶林＞温性针叶林＞亚高山针叶林,而物种丰富度S变化为温性针叶林＞落叶阔叶林＞常绿落叶阔叶林＞亚高山针叶林＞温性针阔混交林.在不同的植物群落中,由于地形地势、坡度、土壤、水热条件等原因,其物种多样性指数不同,但其多样性测度指标除物种丰富度外均呈现出基本一致的变化趋势.随海拔的升高,大熊猫栖息地物种丰富度、多样性指数和均匀度变化先增加,然后下降,最后趋于平稳.坡度不是影响卧龙野生大熊猫栖息地生物多样性的关键因子.不同的坡向其物种丰富度S变化为西＞北＞东＞南,物种多样性指数H'、D呈现西＞南＞北＞东的递降格局,均匀度指数Jsi呈现南＞西＞东＞北的递降格局.在不同的群落中,物种丰富度变化表现为灌木层＞乔木层＞草本层,且42.9%群落中乔木层大于灌木层、64.3%群落中乔木层大于草本层、92.9%群落中灌木层大于草本层,落叶针叶林乔木层树种丰富度小于灌木层和草本层,但其灌木层物种丰富度大于草本层.在同一或不同生长型中,物种多样性指数和均匀度指数变化大体一致. 相似文献
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【目的】探讨凉水自然保护区3类森林的植物组成和林分结构特征,以期为小兴安岭保护区科学管理及经营天然次生林提供基础支撑。【方法】以存在小兴安岭核心区的凉水国家自然保护区及周边的典型针阔混交林、阔叶林和针叶林3类森林为对象,详细调查乔木层(80块30 m×30 m样地)、灌木层(160块5 m×5 m样地)和草本层(160块1 m×1 m样地)的林分结构特征(树高、胸径、枝下高、冠幅、灌高、灌木直径、灌木盖度、草本株高、乔灌草密度等),分析种类组成并计算物种丰富度指数、多样性指数(Shannon-wiener及Simpson指数)和均匀度指数(Pielou和Alatalo指数),并采用方差分析、冗余分析(RDA)探究林分间的差异。【结果】3类森林有乔木28～30种、灌木22～25种、草本78～90种,其乔、灌、草植物种类差异明显,阔叶树种以白桦最多,针叶树种以兴安落叶松最多,灌木最多的是毛榛子,草本以蚊子草和小叶芹最多;针阔混交林的丰富度指数、多样性指数总体上高于针叶林和阔叶林,而阔叶林的均匀度高于其他2个森林类型;同一森林类型的多样性指数和丰富度指数均表现为草本层乔木层灌木层; 3种森林类型中灌木层的均匀度高于其他层;从结构特征来看,树高和胸径平均为14和18 cm,树高和枝下高表现为针叶林针阔混交林阔叶林,灌木层冠幅表现为针阔混交林阔叶林针叶林,草本层每个种的平均多度与盖度表现为针叶林显著(P0.05)高于针阔混交林;冗余排序分析表明,阔叶林和针叶林的多样性特征差异主要由草本层特征解释,而针阔叶混交林则主要受乔木层结构特征影响,其中阔叶林草本植物的多度、密度和株高等可解释48.4%～62.1%的多样性差异,针叶林可解释30.5%～44.3%;针阔混交林中显著影响多样性的林分特征表现为灌木地径乔木枝下高草本株高乔木胸径,合计分析乔木层、灌木层的特征能解释多样性差异的38.8%～40.1%和27.4%～50.7%。【结论】凉水自然保护区乔木优势种以先锋树种白桦和兴安落叶松等为主,个体较小,尚需更长时间保护才能恢复为高质量森林资源;草本层的植物多样性最高,在多样性保护中需关注;植物多样性能在林分结构恢复中得以协同提升,但不同森林类型差异明显,如针阔叶混交林调控乔木枝下高和灌木密度等更有效,而针叶林和阔叶则是调控草本密度或改善草本生长环境才能更有效改善植物多样性。 相似文献
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《浙江林业科技》2014,(1)
通过380个浙江省生态公益林中常绿阔叶林、针阔混交林、松林、杉木林4种主要森林群落的典型样地调查,对不同群落类型物种多样性的时空格局进行研究,结果表明:在空间格局上不同群落类型物种多样性存在较大差异,乔木层多样性指数以针阔混交林和常绿阔叶林为最高;针阔混交林的下木层物种数最高,其次是常绿阔叶林,但下木层各指数在各林型间均无显著差异;杉木林下草本层物种数指数最高,松林草本层各项指数都最低。从时间格局分析,不同群落类型的多样性指数随年龄变化各不相同,常绿阔叶林和针阔混交林乔木层物种数在幼龄-中龄-近熟阶段趋势一致,均为先大幅增加然后略有下降,两种针叶林型的物种数都相对稳定;4种主要群落类型的乔木层Simpson生态优势度指数D,常绿阔叶林和针阔混交林随时间变化趋势一致,均为先增加后略有下降再增加,且显著高于同年龄级的针叶林;常绿阔叶林和针阔混交林乔木层Shannon-Wiener多样性指数H′随时间各异,但都极显著高于同年龄级针叶林的指数。常绿阔叶林和针阔混交林群落物种组成丰富、多样性指数高,是浙江省生态公益林的理想群落与目的群落。 相似文献
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不同森林类型土壤肥力状况研究 总被引：1，自引：0，他引：1
利用贵州天保工程效益监测网络设置在9个监测县和2个自然保护区的101个固定样地土壤分析结果,按常绿落叶阔叶林、常绿阔叶林、落叶阔叶林、针阔混交林、针叶林、针叶混交林、灌木林、竹林等8种不同森林植被类型在不同基岩发育的森林土壤中营养元素含量,对不同森林土壤的综合肥力进行分析评价。结果显示,不同森林植被类型的森林土壤的A层土中有机质、水解性氮、有效磷、速效钾等各项指标含量与森林植被类型呈正相关趋势且高于B层,B层土随不同基岩不同而有所变化,显示不同森林植被类型对土壤综合肥力的影响大于基岩;不同森林植被类型土壤的综合肥力大小顺序依次为:常绿落叶阔叶林>常绿阔叶林>针针混交林>落叶阔叶林>灌木林>针阔混交林>针叶林>竹类。 相似文献
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武夷山国家级自然保护区植物物种多样性研究 总被引：44，自引：0，他引：44
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。 相似文献
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《西部林业科学》2015,(6)
采用典型取样的方法,对大亮子河国家森林公园臭冷杉-红松林和以白桦为主的阔叶混交林植被群落物种多样性进行了调查分析。结果表明,在臭冷杉-红松林8块样地内共有维管植物66种,隶属34科56属,阔叶混交林6块样地内共有维管植物77种,隶属33科62属。从不同群落类型同一植被层看,臭冷杉-红松林草本层物种丰富度指数小于阔叶混交林,两种群落类型乔木层和灌木层各物种多样性指数差异不明显;而草本层差异明显,阔叶混交林物种丰富度指数、Simpson指数和Shannon-Wiener指数较高,仅臭冷杉-红松林的Pielou均匀度指数略高。从同一群落类型不同植被层看,两种群落类型的物种丰富度指数与Shannon-wiener多样性指数均表现为草本层乔木层灌木层;Simpson指数均为乔木层灌木层草本层;物种均匀度指数均表现为灌木层高于乔木层和草本层,其中臭冷杉-红松林草本层均匀度指数略高于乔木层,而阔叶混交林中正好相反。 相似文献
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基于2018年对广东罗浮山省级自然保护区5种典型植物群落物种调查数据,分析了各群落的物种组成、垂直结构,选取物种丰富度指数、Simpson优势度指数、Shannon-Wiener多样性指数及Pielou均匀度指数描述植被多样性特征。结果表明:不同林型植被监测样地共记录野生维管植物210种,分属于81科158属,其中,蕨类植物有10科10属11种,珍稀濒危保护植物4种。优势物种主要包括马尾松、木荷、黄樟、密花树等。通过群落聚类分析和群落乔木层主要优势种重要值排序分析,可将16个样地聚为3种森林植被类型、5种群落类型,包括马尾松针叶林、马尾松+木荷针阔混交林、黄樟+华润楠+青冈常绿阔叶林、华润楠-密花树常绿阔叶林、密花树山顶矮林。群落垂直结构可分为乔木层、灌木层、草本层、层间藤本4个层次,乔木上层的建群种主要是黄樟、马尾松,乔木中层常见的优势种有罗浮柿、密花树和木荷,乔木下层高1～5 m,优势种主要有密花树、豺皮樟等。不同群落植物多样性和结构差异明显,季风常绿和山地常绿阔叶林的物种丰富度指数明显高于针叶林、针阔叶混交林和山顶矮林。 相似文献
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A. Lehtijärvi H. T. Doğmuş‐Lehtijärvi A. G. Aday Kaya S. Ünal S. Woodward 《Forest Pathology》2017,47(6)
Although several Armillaria species have been reported in Turkey, there is little information about their ecology in Turkish forests. In this study, we investigated five forest stands, approximately 5–74 ha in size, in Kastamonu province in the Black Sea Region of Turkey for the presence of Armillaria species in stumps and logs. The stands were mixed Abies nordmanniana ssp. bornmülleriana and Pinus sylvestris forests managed using a selective cuttings system; the proportion of fir in the total number of stems and stumps ranged from 36 to 98%. Based on sequence analysis of the internal transcribed spacer and intergenic spacer regions of the rDNA, all rhizomorphs sampled from the stumps and logs were of Armillaria ostoyae. The size of the genets was estimated with random amplified microsatellites analysis of the isolates and ranged from single stumps to approximately 450 m2. One to seven genets were found in each stand. These results indicate that the genets had arisen from spores and vegetative spread was limited on most sites. 相似文献
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通过对上海松江中央公园内65株特大银杏树白蚁为害情况的调查,发现该公园银杏受害率为100%,其中存在活白蚁的银杏占总量的56.9%,采用毒土处理、粉剂疗法、建立白蚁监测点等措施,经过两次灭杀,活白蚁的灭杀率达到92.3%和93.3%,从而使存在活白蚁银杏树的比例从56.9%下降到2.7%,白蚁发生情况明显降低。
相似文献
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建平半干旱地区石质山地造林技术研究 总被引：1，自引：0，他引：1
研究了不同植物在石质山地的造林成活率、土壤化学性质随造林年限的变化和造林措施对土壤化学性质和植物胸径、树高年净生长量的影响。结果表明：不同植物在石质山地的成活率在21%～85%之间,其中白榆和沙打旺的成活率分别为81%和85%,而小叶杨、刺槐、栾树的成活率均在70%左右;植被能明显提高石质山地不同土层的有机质、全N、P2O5含量,但提高程度随土层深度、养分种类和造林年限的不同而不同;在同一土层,生物复合肥料、菌剂和保水剂均显著提高土壤有机质含量（p〈0.01）并显著降低土壤P2O5含量（p〈0.01）;只有保水剂可引起土壤全K含量的明显升高;生物复合肥料、菌剂和保水剂均显著提高白榆、小叶杨、刺槐、栾树树高和胸径的年净生长量,但保水剂的提高程度最高。 相似文献
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植物经常暴露在各种生物和非生物的胁迫之下,这些胁迫会影响植物的生长发育和繁殖并最终导致植物死亡。为了抵御不利的环境条件,植物已经进化出复杂而精细的网络来感知胁迫并激活防御系统。为此,植物激活许多信号转导通路,这些信号转导通路可以改变一些胁迫响应基因的表达,从而引起植物形态、生理和生化的改变以适应逆境。DNA胞嘧啶甲基化是高等真核生物的主要表观遗传机制之一,在维持基因组稳定性和调节基因表达方面起着关键作用。表观遗传变异比遗传变异更为灵活。一旦环境条件发生变化,为了适应新的环境植物都会发生表观遗传的改变。许多研究表明DNA甲基化参与植物的发育和应激反应。基于相关研究对DNA甲基化进行了综述,对植物逆境胁迫有重要意义。 相似文献
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《Scandinavian Journal of Forest Research》2012,27(6):530-542
Abstract The success of natural regeneration on patch clear-cuts in Norway spruce stands in Southern Finland was examined in terms of stocking and tree height. The experiment was established in mature spruce stands in the submesic Myrtillus (MT) site type. In each of the eight study sites, three plots were treated with clear-cutting and planting, clear-cutting with partial tree retention and planting, and patch clear-cutting without site preparation, respectively. In three of the study sites, one plot with patch clear-cutting and site preparation was established. Each plot was 1 ha, out of which three patches of 40×40 m were clear-cut in the patch treatments. 10–11 years after cutting, the patches had on average 1316 crop trees ha–1, of which 91% were spruces. Some 27% of the stands were up to the target stocking level (≥1600 ha?1), and 36% were at least satisfactory (≥1300 ha?1). Site preparation did not yield greater stocking levels on patches, but that result is ambiguous due to a difference in initial stocking. The average spruce tree height in the patches (0.76 m) was much smaller than in the case of clear-cutting and planting (2.42 m). In conclusion, the patches had been restocked tolerably well with spruce and birch for practical purposes during the 10- to 11-year period, but the regeneration process had been very slow compared to clear-cutting and planting. 相似文献
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The study focused on the success of regeneration on patch cuts in spruce-dominated stands in terms of stocking and tree height. It was based on an experiment in the Kainuu region in northern Finland. The experimental design included 8 stands with 58 clearcut patches of variable size (0.09–0.37?ha), on which either natural regeneration without site preparation or site preparation and planting of Scots pine was applied. A regeneration survey was conducted 13–15 growing seasons after treatments. Patches without site preparation had been restocked quite well from natural seed sources. The average number of trees was about 11,000?ha?1, of which 1700?ha?1 crop trees. With site preparation and planting, the stocking levels were also very high, 25,000 and 2100?ha?1, respectively. One hundred percent of the planted patches and 75% of the naturally regenerated patches had an acceptable density. Restocking was equally good across the range of patch sizes. Tree growth had been somewhat slower in the smallest patches than in the largest ones in the range. Natural regeneration was capable of yielding good regeneration results in most patches, especially when site preparation was applied. Stocking levels and height development were higher yet in the planted patches. 相似文献
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Keisuke Kojiro Yuzo Furuta Makoto Ohkoshi Yutaka Ishimaru Misao Yokoyama Junji Sugiyama Shuichi Kawai Takumi Mitsutani Hiromasa Ozaki Minoru Sakamoto Mineo Imamura 《Journal of Wood Science》2008,54(6):515-519
To investigate the changes in microstructures of wood with elapsed time in the environment, CO2 adsorption onto dry wood was measured at ice-water temperature (273 K) for samples aged from 0.1 years to over 1000 years.
The micropore size distribution was obtained using the Horvath-Kawazoe method. Micropores smaller than 0.6 nm in wood decreased
in number with elapsed time in the environment, and a negative correlation was found between cumulative pore volume for pores
smaller than 0.6 nm and elapsed time in the environment. Cumulative pore volume in the 1000-year sample was almost half of
that in the 0.1- year sample. Micropores smaller than 0.6 nm in wood with a few decades or more of elapsed time increased
in number after rewetting and drying. Consequently, microstructures of wood with longer time elapsed in the environment were
considered to be more stable, because of longer-term thermal motion and possibly more repeated moisture adsorption and desorption
and/or temperature variation in the environment. 相似文献
20.