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油松天然次生林昆虫群落结构及多样性的研究 总被引：4，自引：0，他引：4
该文对燕山浅山区油松天然次生林中昆虫（包括蜘蛛）群落的种类组成、垂直结构、季节变化以及不同林分类型中昆虫群落的变化情况进行了初步研究。在燕山浅山区油松天然次生林中存在着种类丰富的昆虫和蜘蛛，包括昆虫纲的１９目、８９科、５５２种，蜘蛛纲的２目５６种，其中天敌类群占总种数的３０．５％，植食性种占６４．９％；在林内垂直方向上，以下木层昆虫种类最为丰富；在不同时间上，以７、８月份昆虫种类最为繁多。对不同林分类型昆虫种类及多样性的研究表明，混交林中昆虫种类多于纯林，其群落多样性也高于纯林；人为干扰较少的林分中昆虫种类多于人为干扰严重的林分，其群落多样性也较高。混交林和保护较好、生长旺盛的林分中昆虫种类更为复杂，其数量分布也更为均匀，群落多样性和稳定性也较高，某一种昆虫数量剧增到猖獗水平的可能性也较小，故害虫爆发成灾的概率较小 相似文献
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在西双版纳热带雨林中的木瓜榕和对叶榕两个种群内共采集昆虫标本20088号，其中访问木瓜榕的昆虫有8目21科33属，共40种，在对叶榕上采集到37种昆虫，隶属于7目21科32属。两种榕树的昆虫群落组成特点表现为：害虫种类多，种类达群落总种数的94．6％－97．0％，但个体数量少，主要是鳞翅目、鞘翅目及同翅目等类群的昆虫；许多昆虫既喜食榕果又可危害叶片，部分种类仅取食叶片和蛀干；这些类群中在隐头花果内外活动的昆虫种类最多，达54％，数量上占到93．1％－94．3％。益虫种类少，则个体数量多，尤其是传粉榕小蜂和群数量占绝对优势（86．4％－90．2％），它的成功传粉影响着榕树群落的构建和稳定。 相似文献
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象头山自然保护区昆虫种类已知356种。对昆虫种类组成、群落结构和经济种类进行分析,并对保护区昆虫保护和资源合理利用进行探讨。结果表明鳞翅目种类最多,共117种,占32．87％,沟谷及水库周边的植被上昆虫种类数量和密度均大于山顶。林业害虫有31种,天敌昆虫有57种。 相似文献
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贵州省松杉种子园天敌昆虫种类调查及其利用和保护 总被引：1，自引：0，他引：1
不得９９１～１９９２年，经６个松杉种子国调查，共采集天敌昆虫５０余种，已鉴定４１种，隶属于８目１６科．在不同的种子园中，由于树种的不同和自然地理条件的改变，天敌昆虫的种类和数量也各不相同．马尾松球果害虫天敌寄生率达３８％． 相似文献
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系统地研究了自然分布北界区域马尾松毛虫天敌昆虫种类（包括蜘蛛）。共记录捕食性知敌昆虫23种，寄生性天敌昆虫30种，其中14种天敌为我省首次记载发现。 相似文献
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桉树人工林昆虫群落结构及其多样性初步调查 总被引：2，自引：0，他引：2
对桉树人工林系统昆虫种类进行调查和鉴定,记录了桉树人工林昆虫种类共有16目63科106种．从群落物种数来看．鞘翅目的物种丰富度最高（20．56％）;从物种的个体数量看,鳞翅目昆虫的数量最多（30．71％）;桉树林昆虫总的群落多样性指数为1．3933,均匀性指数为0．9301,鞘翅目的群落多样性指数（0．2937）和均匀性指数（0．2108）都最大．文中就昆虫群落多样性与稳定性的关系以及如何抑制害虫发生等问题进行了讨论． 相似文献
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《河北林果研究》2015,(2)
以承德市滦平县西沟乡山地梨园为研究区,采用网捕和陷阱等方法对节肢动物群落进行调查,分析冀北山区梨园节肢动物的物种组成、群落结构、生物多样性及季节动态变化,然后通过对喷洒低毒广谱杀虫剂梨树与未喷洒药剂梨树上昆虫的种类、数量进行对比分析,研究使用低毒广谱杀虫剂对节肢动物群落各参数的影响。结果表明:除5月份昆虫种类减退率为49%外,其他月份昆虫种类和个体数量上的减退率大都在70%~90%之间,说明喷洒农药可以明显降低林冠层昆虫的种类和个体数量,对害虫有一定的防治作用;在试验的4个月内,园内昆虫群落的相对稳定性值未降反升,由此推出,喷洒农药对梨园林冠层的昆虫群落多样性有一定的促进作用;在调查月份中,植食性昆虫种类数量减退率达36%~72%,而捕食性和寄生性昆虫所占群落的比例都有不同程度的上升,说明喷洒低毒广谱杀虫剂能够相对降低有害昆虫的比例,增加天敌昆虫的数量。 相似文献
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抚顺地区森林昆虫资源调查研究 总被引：1，自引：0，他引：1
调查了解森林昆虫种类组成，以及不同林分类型的森林害虫分布范围和危害状况，林木害虫的天敌种类、数量及利用价值等，不仅对治理森林害虫，保护森林安全发挥积极作用，而且对天敌昆虫的利用提供理论依据。于1984-1995年，对辽宁省抚顺地区的森林昆虫资源进行了较深入的调查研究。通过调查，已发现该地区的森林昆虫种类有18目、185科、l660种，基本摸清了各林分娄型的主要森林昆虫种类．并提出了防治对策。 相似文献
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迭部林区主要害虫防治对策 总被引：2，自引：2，他引：0
迭部林区主要害虫防治对策刘铭汤，张承维，卢子华，张俊海（西北林学院）（迭部林技站）一、迭部林区主要害由的确定原则和种类１．主要害虫的确定原则经过课题组３年的努力，采集昆虫１０１２种，其中害虫有８０７种，天敌昆虫有１５８种。我们根据危害的严重程度及分布... 相似文献
11.
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
12.
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
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