共查询到19条相似文献，搜索用时 187 毫秒
1.
在尖峰岭热带山地雨林中,对食叶昆虫食叶量测试,供试树种计有27科50种。所得结果表明:昆虫食叶面积或重量百分率,各树种变动幅度在0.45％～28.01％之间,平均为7.71％,这种食叶量水平,对林木生长并无影响。但食叶昆虫的存在,对热带森林生态系统来说,在维持生物群落动态平衡方面,起着积极作用。 相似文献
2.
通过在辽宁抚顺市大伙房实验林场,对兴安落叶松鞘蛾食叶量的测定研究结果看出,该鞘蛾一头越冬幼虫平均取食针叶长度为１８４ｍｍ,危害针叶数量为２５枚;在危害期间不同时间段的食叶量和危害量各异,开始取食后的前１０ｄ危害最大,食叶量和危害量分别占整个危害期的８６％和９４％。针叶被害率与虫口密度密切相关,当虫口密度为２．９、５．８、８．７头／１０ｃｍ和１１．７头／１０ｃｍ时,针叶被害率分别为２５％、５０％、７ 相似文献
3.
湖南桃江黄脊竹蝗食叶量与危害叶量观察 总被引：1，自引：0，他引：1
本文以黄脊竹蝗为观察对象，通过套笼，每日套换新叶饲养黄脊竹蝗，测定出雌蝗食叶量、雄蝗食叶量、各龄期食叶量，以及黄脊竹蝗逐日食叶量与危害叶量。 相似文献
4.
根据松毛虫按时间序列有节奏的取食规律，从春季松毛虫上树终止之日起，逐日测定松毛虫群体中个体的平均排粪量，利用排粪量与食叶量的相关关系计算出逐日食叶量、残害量，再利用数学回归方法，建立了松毛虫逐日取食曲线的回归模型与逐日累计取食曲线的回归模型。本文中的取食量采用重量单位来描述，从而避免了用针叶长短测量取食量时针叶粗细不一所产生的误差。取食量数学模型的建立为准确的定量研究松毛虫种群动态与食叶量的关系提 相似文献
5.
黄褐天幕毛虫幼虫食叶量观测及防治指标的测定 总被引：4，自引：0，他引：4
该文探讨了荒漠地区黄褐天幕毛虫Ｍａｌａｃｏｓｏｍａ ｎｅｕｓｔｒｉａ ｔｅｓｔａｃｅａ Ｍｏｔｓｃｈｕｌｓｋｙ幼虫的食叶量。人工模拟不同摘叶强度对胡杨高、径生长量的方差分析及多重比较,Ｆ〉Ｆ０．０１,Ｄ〉Ｄ。摘叶３０％、５０％与摘叶１００％之间高,径生长量差异极显著。掌握了胡杨１００ｃｍ标准枝承受的害虫幼虫数及允许受害密度,建立了胡杨对单株材积生长量的一元回归方程：Ｙ＝２７．６８１８１＋２５１４２ 相似文献
6.
文山松毛虫生命表组建及幼虫食叶量测定 总被引：7，自引：1，他引：6
在云南松人工林中选择９株样株，对文山松毛虫第１代４５００粒卵加以标记，经过幼虫、蛹和成虫不同虫期的存亡状况的跟踪观测，获取不同虫期的存活率，组建自然种群生命表。由生命表得出，文山松毛虫第１代种群数量的很大程度上受外界环境条件特约，整个世代死亡率高达９９．８７％。通过３０头第１代幼虫室外套笼饲养、食叶量测定的结果表明：幼虫期单虫的总食叶量为４８４２ｃｍ；不同龄期幼虫食叶量不同，１￣３龄较少（为６０１ 相似文献
7.
该文探讨了荒漠地区黄褐天幕毛虫ＭａｌａｃｏｓｏｍａｎｅｕｓｔｒｉａｔｅｓｔａｃｅａＭｏｔｓｃｈｕｌ－ｓｋｙ幼虫的食叶量。人工模拟不同摘叶强度对胡杨高、径生长量的方差分析及多重比较，Ｆ＞Ｆ０．０１，Ｄ＞Ｄ＊，摘叶３０％、５０％与摘叶１００％之间高、径生长量差异极显著。掌握了胡杨１００ｃｍ标准枝承受的害虫幼虫数及允许受害密度，建立了胡杨幼树单株材积生长量的一元回归方程：Ｙ＝２７．６８１８１＋２５１４２．３５９５７Ｘ。提出天幕毛虫幼虫防治指标：３．４头／１００ｃｍ标准枝，投入防治费用等于挽回经济损失的危害比例为３３．４％，即害虫幼虫危害大于摘叶３３．４％以上，则应立即防治。 相似文献
8.
本文采用室内与林间饲养幼虫的方法,对赤松毛虫Dendrolimus spectabilisButier幼虫的食叶量进行了研究。结果表明,幼虫的食叶量随着龄期的增加而增大。1头幼虫-生取食油松针叶长度为3794.52厘米,相当于针叶湿重22.97878克,折算成干重为10.52003克,其中以老熟幼虫食叶量最大,占一生食叶总量的75％左右。赤松毛虫对油松针叶的残害量为215.51厘米,危害量是4010.03厘米。群体饲养与单体饲养对幼虫的食叶量无显著影响,雄虫的食叶量相当于雌虫食叶量的73.4％。幼虫对2年生和3年生针叶的取食量无显著差异。室内饲养的幼虫由于环境的改变、其食叶量明显低于林间幼虫的食叶量。 相似文献
9.
本文提出食叶害虫对树木的影响是多方面的，例如，对树木体内化学物质（碳水化合物、氨基酸、苯酚）和树木生长量（叶量、径生长量和高生长量）均有一定的影响。同时，提出了防治食叶害虫的林业技术措施，例如，抗虫育种、调整林木组成及林分密度和促进纯林异龄化等 相似文献
10.
11.
2000—2012年,通过10余年的观察,对近年来杨树食叶害虫的发生情况进行资料收集汇总,梳理分析影响杨树食叶害虫发生的因子,对杨树食叶害虫的发生与树种、气候、监测、防治、营林等方面的关系进行了分析与对比,找出杨树食叶害虫发生发展规律,总结经验教训,研讨解决办法,保护森林资源不受侵害。 相似文献
12.
经济林害虫发生现状与趋势 总被引：5，自引：0，他引：5
选择安徽省28种主栽及名特经济树种为主要对象,经过1988年至1995年8年的调查研究,探明当前各经济树种害虫种类、发生现状与趋势。在28种经济树种上查出害虫1074种,其中危害程度轻微、中等、严重的害虫分别为868种、137种和69种,分别占害虫总数的80.8%、12.8%和6.4%。经济林害虫垂直结构为食叶害虫（626种）>枝梢害虫（290种）>蛀干害虫（78种）>果实害虫（43种）>根部害虫（37种）。害虫总体发生率78.0%,其中危害轻微、中等和严重的发生率分别为41.3%、22.3%和14.4%。分析提出现阶段害虫发生类型。 相似文献
13.
Eben N. Broadbent Gregory P. Asner Marielos Peña-Claros Michael Palace Marlene Soriano 《Forest Ecology and Management》2008
Large-scale inventories of forest biomass and structure are necessary for both understanding carbon dynamics and conserving biodiversity. High-resolution satellite imagery is starting to enable structural analysis of tropical forests over large areas, but we lack an understanding of how tropical forest biomass links to remote sensing. We quantified the spatial distribution of biomass and tree species diversity over 4 ha in a Bolivian lowland moist tropical forest, and then linked our field measurements to high-resolution Quickbird satellite imagery. Our field measurements showed that emergent and canopy dominant trees, being those directly visible from nadir remote sensors, comprised the highest diversity of tree species, represented 86% of all tree species found in our study plots, and contained the majority of forest biomass. Emergent trees obscured 1–15 trees with trunk diameters (at 1.3 m, diameter at breast height (DBH)) ≥20 cm, thus hiding 30–50% of forest biomass from nadir viewing. Allometric equations were developed to link remotely visible crown features to stand parameters, showing that the maximum tree crown length explains 50–70% of the individual tree biomass. We then developed correction equations to derive aboveground forest biomass, basal area, and tree density from tree crowns visible to nadir satellites. We applied an automated tree crown delineation procedure to a high-resolution panchromatic Quickbird image of our study area, which showed promise for identification of forest biomass at community scales, but which also highlighted the difficulties of remotely sensing forest structure at the individual tree level. 相似文献
14.
Guadalupe Williams-Linera Claudia Alvarez-Aquino Estela Hernández-Ascención María Toledo 《New Forests》2011,42(2):131-148
Secondary successional vegetation represents one-third of the 7% of the original area covered with tropical dry forest that
remains in central Veracruz, Mexico. In this region, fallow periods are short, in general, no longer than 7–10 years, and
old secondary successional sites are not available. Therefore we evaluated the potential of very early successional stages
of tropical dry forest with different land use histories for recovering the structure and composition of regional forest.
We compared five early successional sites (7–72 months) with five nearby forest remnants. Successional sites had reached 38
and 30%, respectively, of the average basal area and density recorded for the forest understories, but only 5 and 10%, respectively,
of the basal area and density of forest overstories. A total of 132 tree species were recorded, 45 at successional and 107
at forest sites. Individuals of tree species with animal-dispersed seeds (57%) were significantly better represented than
wind-dispersed (22%) and self-dispersing (21%) species in both successional and forest sites. Successional sites had already
recruited 10% of the intermediate and shade-tolerant species that grow in forest remnants. However, only 20 species occurred
in both early successional and forest sites, several showing resprouting ability. We conclude that the entry of forest species
to the successional process at very early stages and the recruitment of individuals from resprouting may facilitate the recovery
of the dry forest in Veracruz. 相似文献
15.
稠李巢蛾是我国北部林区稠李等灌木林的重要食叶害虫之一。通过试验结果论述了稠李巢蛾的特征及其防治方法。 相似文献
16.
17.
通过对海南岛霸王岭热带山地雨林林隙更新生态位的研究表明：同一树种在不同大小和年龄级林隙内的优势度不同，不同树种在同一大小和年龄级林隙内的优势度不同。根据树种在不同大小级林隙内的生态位宽度的变化，可分为生态位幅度宽、中等、较小和狭小4类；根据树种在不同年龄级林隙内的生态位宽度的变化，可分为对林隙时间生态资源利用充分、利用较充分、利用不充分和利用很少的4类树种。不同的树种或树种组对不同大小和年龄阶段林隙生态资源利用的不一致性，表明热带山地雨林中不同树种的林隙大小级生态位和林隙时间段生态位是相对分离的。分析表明，海南岛热带山地雨林中有很大一部分树种是属于低密度、狭生态位的树种。从物种多样性的角度来看，大量低密度、狭生态位树种的存在表明热带山地雨林是一种较为脆弱的生态系统类型。 相似文献
18.
In tropical regions where agricultural activities are limited, agroforestry is an alternative for both economic development and for the management and conservation of biodiversity. The potential role of different types of land use as reservoirs of dung beetle diversity in the wet tropical forest of the Pacific lowlands of Colombia is evaluated in three agroforestry systems that differ in canopy cover and the sowing density of Borojoa patinoi crops associated with timber forest. Although total species richness was similar among land use types, differences related to the decrease in the abundance and biomass of the species were remarkable, and reflected in turn by the diversity and structure of the guilds. The general pattern observed was one in which the structure of the dung beetle assemblage of B. patinoi growing below a diversified and permanent tree cover was similar to that of the primary and secondary forest. Beetle diversity in management systems with less tree cover or a high sowing density of B. patinoi was lower and very similar to that of abandoned agricultural fields. This suggests that B. patinoi agroforestry systems can be viewed as valuable instruments for biodiversity management and conservation in the wet tropical forests of the Pacific lowlands and not just as substitutes for forest, though we must be aware that structural changes in the beetle community may in turn affect the ecological processes regulated by these insects in the agrosystems under study. 相似文献
19.
近50年来,通过树种调查、繁殖技术研究、造林试验,在西双版纳普文林场,成功地培育出8种热带雨林标志树种的人工林及7种热带山地雨林标志性树种的人工林,并散生培育热带雨林树种12个。还在热区退化地造林中评选出了2个造林先锋树种。它们既形成了高大整齐的林分外貌,也逐步形成了多层次多物种的森林复层结构。在这些人工林下出现了众多的雨林标志树种的天然更新幼苗幼树,说明这些人工林所形成的雨林环境具有可持续经营性。实践表明,西双版纳的热带雨林是可人工恢复的。 相似文献