湘中盆地丘陵区马尾松毛虫成灾机制的初步调查研究

通过选择相似的地理条件，对马尾松毛虫不同发生类型和实施不同持续控制技术措施的马尾松林进行调查研究，经分析认为：马尾松林生态环境因子是影响马尾松毛虫种群消长的重要因素，马尾松林中马尾松重要值愈小，植物种类多样性指数和昆虫多样性指数愈高，松林自控松毛虫能力就愈强；反之，松林中马尾松重要值愈大，，植物种类和昆虫多样性指数愈低，松林自控能力差，松毛虫易暴发成灾，通过对不同发生类型的松林采取不同持续控制技术措施，可增强松林自控能力，从而达到持续控制虫灾的目的，并据此提出了持续发展技术体系。     

马尾松毛虫常灾区、偶灾区和无灾区松针挥发物特征

【目的】马尾松毛虫是我国发生最为严重的针叶林食叶害虫,呈现周期性暴发。不同暴发区松林生理特征影响松毛虫暴发过程的机制还不清楚。植物挥发物参与了许多重要的生理、生态过程,通过揭示不同松毛虫发生区域马尾松挥发物的释放特性,以及不同地区的松针挥发物含量与松毛虫暴发情况的相关性,可为更加精确地利用植物挥发物进行松毛虫趋避或者天敌引诱提供可靠的依据。【方法】在广西凭祥大青山地区选取3个典型的松毛虫暴发类型区即无灾区、偶灾区和常灾区,鉴定并比较3个林场松针挥发物的组分及含量。【结果】马尾松针叶挥发物主要包括 S －α－蒎烯、R －α－蒎烯、月桂烯、R －β－蒎烯、S －β－蒎烯、(+)－3－蒈烯、α－萜品烯、(+)－柠檬烯、(－)－柠檬烯、γ－萜品烯。常灾区、偶灾区和无灾区的松针挥发物组成比例差异很大。这些挥发物可以分为4类：第1类包括 R－α－蒎烯和月桂烯,与马尾松毛虫的暴发频率呈负相关( P ＜0.05);第2类包括S－β－蒎烯、γ－萜品烯和 (+)－3－蒈烯,与马尾松毛虫的暴发频率呈正相关(P＜0.01);第3类包括 R －β－蒎烯和(+)－柠檬烯,它们在3种松毛虫暴发区域的松针挥发物中呈现显著但不规则变化(P ＜0.05),最后一类包括S－α－蒎烯,(－)－柠檬烯和α－萜品烯,它们在3种松毛虫暴发区域的松针挥发物中无明显变化。【结论】松针挥发物的组成比例可能影响松毛虫的暴发情况。另外,天敌是控制松毛虫的重要因子,因此松针挥发物对马尾松毛虫天敌的作用程度也可影响害虫的暴发;无灾区或者偶灾区的针叶挥发物可能吸引更多的松毛虫天敌,从而对松毛虫的暴发起一定的控制作用。     

马尾松毛虫不同发生类型的划分及其防治对策和防治效益的探讨

本文通过多年的调查资料，根据松林作业小班的地理生态环境、虫情发生特点等综合因素来划分马尾松毛虫不同发生类型，改变了以往单从松林的海拔、林相、植被、土壤等条件来划分发生类型的方法，较为准确合理。以此划分为基础，对以“虫源地”为重点的松毛虫重灾区、常灾区进行综合治理，取得了显著的经济效益和生态效益。     

浙江省马尾松毛虫寄蝇调查

马尾松毛虫是我国马尾松分布地区的一种重要害虫,在丘陵半山区经常暴发成灾。大发生时,食尽松针,严重影响松林的正常生长,并影响人畜安全。寄蝇是马尾松毛虫的主要寄生性天敌之一,对马尾松毛虫的发     

对马尾松毛虫预测预报中几个问题的探讨

马尾松是我区主要用材林之一,总面积达451万亩。历年来,由于松毛虫的严重危害,使松林资源受到很大损失。据统计,全区12个县(市)中就有10个县(市)属松毛虫常灾区,一般3～5年为一个暴发周期,大发生时受害面积约60～80万亩。松林受害后,重者大片枯死,轻者影响生长。     

不同林分类型马尾松毛虫卵寄生率调查

寄生马尾松毛虫卵期的寄生蜂有10多种,优势种有赤眼蜂、黑卵蜂、平腹小蜂。通过研究不同林分类型的马尾松毛虫卵期天敌寄生率的变化,探讨马尾松毛虫卵期寄生性天敌对马尾松毛虫的控制作用。利用接种式调查方法对东至县金寺山林场马尾松毛虫卵期天敌寄生率进行调查。结果表明,在不同林分类型条件下,第二代卵期黑卵蜂寄生率马尾松林样地大于湿地松林样地,黑卵蜂平均寄生率差异性显著,说明马尾松林和湿地松林样地内黑卵蜂寄生率差异较大。     

马尾松毛虫不同发生类型的划分及其防治对策和防治效益的探讨

本文通过多年的调查资料，根据松林作业小班的地理生态环境，虫情发生特点等综合因素来划分马尾松毛虫不同发生类型，改变了以往单从松林的海拔，要相，植被，土壤等条件来划分发生类型的方法，较为准确合理，以此划分为基础，对以“虫源地”为重点的松毛虫重灾区，常灾区进行综合治理，取得了显著的经济效益和生态效益。     

衢州马尾松毛虫空间格局及其抽样技术

马尾松毛虫是我国南方马尾松林的主要害虫,研究马尾松毛虫的空间格局,对于深入了解松毛虫的生物学特性,选择、确定合适的估计种群密度的抽样调查方法和该虫在不同生境条件下种群消长的规律,有着十分重要的意义,同时也为确定合理的防治指标提供重要的依据。本文通过对衢州市开元寺、荆溪、横路、华墅的马尾松林和马尾松毛虫(1984)第一、第二代、越冬前、越冬代     

沿江低山丘陵区马尾松毛虫控制的研究

马尾松毛虫是沿江低山丘陵马尾松林的历史性害虫，自1980年以来，我们坚持调查和观察，通过采取“虫源地”形成与发生、发展规律的探讨、马尾松毛虫幼虫种群密度简易估计模式模拟和应用、以无公害农药为主，“治点保面”综合治理的协调措施，控制“虫源地”潜伏阶段，达到有虫不成灾，获得少投资、高效果、长效益的目的。贵池区自1992年至今，马尾松毛虫没有暴发成灾，明显地避免了马尾松毛虫发生周期。     

湘西南马尾松毛虫发生规律与环境因子的关系

对湘西南山区马尾松毛虫发生规律与环境因子关系进行了分析,发现在山区温、湿度和降雨量对马尾松毛虫发生都有影响,但不是单因子发生主要作用;在山区南坡山脊、林缘、8～15年树龄的松树中马尾松毛虫分布较多;海拔500m以下、东坡和干燥林地中的松林,马尾松毛虫为害严重,纯林和混交林为害同等严重。     

Past and present outbreaks of the balsam fir sawfly in western Newfoundland: An analytical review

Historical data of defoliation and population density were examined to determine whether a sustained outbreak of balsam fir sawfly (Neodiprion abietis Harris) in western Newfoundland, Canada is unprecedented in severity and duration. Results indicate that the current outbreak departs substantially from historical trends, covering a surface area twice the sum of all infestations occurring in the preceding 50 years. The current outbreak is also of longer duration due to a northward expansion of the range usually subjected to severe defoliation by this insect. Time-series analysis indicates that balsam fir sawfly dynamics have a strong second-order component, providing testable hypotheses for future studies investigating the factors responsible for population fluctuations.     

文峪河流域景观格局动态及其驱动力分析

以文峪河流域为研究对象,分析流域2000—2018年景观格局数量动态的面积、转移及速度特征。从斑块类型尺度与景观尺度2个层面选取景观指数分析流域近18年的景观格局动态,并在流域尺度上沿城市—林区梯度线分析沿线景观格局指数的梯度分布,基于数量统计模型对景观格局动态驱动力进行研究。结果表明,流域耕地、林地、草地面积有所减少,向其余地类支出面积,水域、建设用地、未利用地面积增加,向其余地类吸收面积,不同地类土地转移、变化速度情况不同。不同景观类型的格局动态不同,流域整体景观破碎化程度增加,连通性下降、景观规则度下降、景观核心面积下降,不同景观指数的梯度分布特征不同。自然驱动因子、社会驱动因子对流域景观格局变化均具有驱动作用,文峪河流域的景观动态在过去18年间经历了快速、复杂的变化,社会经济驱动因子是景观格局演变的主要驱动力量,经济与人口发展、产业结构及工业化进程是文峪河流域景观格局演变的重要驱动力量。     

Genetic patterns as possible factors causing population cycles in oak leafroller moth,Tortrix Viridana L.

The genetic patterns and their possible effects on population dynamics were studied in Tortrix viridana L. (Lepidoptera: Tortricidae) – a serious pest of oaks in Europe. The following empiric results were obtained: (1) The trends revealed at the Est-4 and Pts-4 loci were directly related to this insect's population dynamics. Heterozygosity at the loci was high during the outbreak phase and low during the population decline and depression phase. In all the cases genetic changes preceded the changes in population density. (2) Plant–larva interactions resulted in strong gene–environment relationships which indicated that carriers of alternative Pts-4 and Est-4 genotypes inhabited different food micro-niches. These gene–environment relationships were shown to be caused by the differential larvae survival. (3) Natural selection (differential survival) at the larva stage worked in favor of the same genotypes in both the males and females within each of the micro-populations. These genotypes further showed, longer body length in adults, and higher fertility in comparison to those genotypes which were `unfit' during the larva phase. (4) Body size appeared to be subjected to sexual selection as well. Females always tended to mate with larger males. Male's mate selection was related to the phase of the population cycle with smaller females having sexual advantage during the outbreak phase and larger females being selected prior to the population decline and, probably, during the depression phase. This mating system based on body size evoked assortative mating for the Est-4 and, probably, Pts-4 genotypes. It was negative-like during an outbreak, and positive at population decline and during depression phase. These results allowed the construction of a model, probably, describing the population cycles in T. viridana. During outbreaks, genetic heterogeneity was high, and numerous two-locus genotypes prevailed in many different food micro-niches. This strategy thus optimized the entire food resource available to the insect. Conversely, when the heterozygosity was low, only the micro-niches of two-locus homozygotes were filled generating heavy competition among the larvae, leading to a high larval mortality. Assortative mating at allozymic loci is suggested to be the main factor regulating genetic heterogeneity in T. viridana. This mechanism could be incorporated into predictive models used to study the population dynamics of T. viridana.     

Gap dynamics in the Western Carpathian mixed beech old-growth forests affected by spruce bark beetle outbreak

Understanding how species-specific disturbances affect the dynamics of mixed forests is becoming increasingly important due to rapidly changing disturbance regimes. This study estimated the effect of Norway spruce (Picea abies (L.) Karst.) mortality on the disturbance processes in two mixed beech stands of the Western Carpathians that were affected by a bark beetle outbreak. We evaluated the size distribution, fraction of canopy and expanded gaps, the characteristics of gapmakers and the contribution of different species to gap size. The measured canopy gap fraction was <5%, and most canopy gaps were small (<100 m²). Spruce was the most abundant gapmaker, and its share among gapmakers was 3–6 times higher than its share in the canopy. We found that the increase in spruce mortality due to the outbreak resulted in a fine-scale mortality pattern. However, spruce gapmakers did not contribute much to gap area size, as shown by a weak correlation between the number of spruce gapmakers and the area of expanded gaps. Diameter distribution of living versus recently dead trees showed that beech mortality occurred disproportionately in large size classes. However, dead spruce trees were equally frequent in all diameter classes, which means beetles did not exclusively attack larger trees in these stands during the outbreak. We conclude that spruce mortality may have influenced successional processes by giving a competitive advantage to two other species that were not affected by the outbreak, provided that a high deer browsing intensity does not hinder the regeneration of new seedlings.

     

海南岛热带天然次生林生长动态研究

本文对两类处于不同演替阶段的天然次生林,从直径生长、胸高断面积生长、材积生长、林木死亡率等方面进行了对比分析。研究结果表明:随着演替的进程,天然次生林直径生长、胸高断面生长和材积生长呈现下降趋势,林木死亡率也呈现明显的下降趋势,其主要原因是,在演替的早期阶段,速生喜光先锋种在林分中占据较高比例,进而林分表现出较高的死亡率和较高的生长力,但是随着演替的进行,喜光先锋速生树种逐步被耐荫的顶级或亚顶级树种所取代,进而表现出低生长和低的死亡率。     

基于RS和GIS的安宁市景观格局动态变化分析

利用1996年和2003年两期遥感数据,在GIS技术和Fragstats软件的支持下,运用景观生态学原理,采用斑块面积、斑块数、斑块密度、形状指数、面积周长分维度指数、聚集度指数、结合度指数、蔓延度指数、香农多样性指数和均匀度指数等从景观类型水平和景观水平对安宁市景观格局的动态变化进行了分析。结果表明,在类型水平上,安宁市的农业用地和荒地面积减少,而林地和水域面积增加,反映出近年来安宁市开展开荒造林和退耕还林工程的成效;从景观水平上来看,景观多样性提高,且趋于均匀,单类型景观占主导地位的程度降低;从斑块密度、分维度指数和蔓延度指数进行分析表明,景观破碎程度增大,斑块形状趋于复杂化,斑块间趋于离散,反映出人类活动对景观格局的干扰特征。     

Population dynamics of tree species in southern Quebec,Canada: 1970–2005

Over the last few decades, several phenomena contributed to modify the structure and composition of the eastern North American forests. Along with forest management, disturbances such as insect defoliation, global environmental changes, acid deposition, and rising atmospheric CO₂ concentrations, have been identified as phenomena that could affect forest structure and composition. Currently, there is very little quantitative information on the resulting effect of multiple disturbances on the main parameters of forest dynamics (growth, mortality, and recruitment). Using available data from the Quebec permanent sample plots network, we analyzed the ecological response of tree species populations to the combined effect of contemporary global environmental changes, disturbance regimes, and forest management practices over the last 30 years in southern Quebec. The results indicate that the main parameters of forest dynamics changed considerably over the last three decades. The last spruce budworm outbreak initiated a successional change in coniferous stands. The basal area of Abies balsamea and Picea glauca, the most abundant coniferous species, decreased by 29.7%, while pioneer species abundance increased. For late successional deciduous species, observed changes in forest dynamics appear to be mainly associated with global environmental changes rather than with natural disturbances or forest harvesting. The results indicate that inferring responses of tree population dynamics to global environmental changes can be very complex or even misleading considering the confounding effects of other disturbance agents. The results also suggest that the ecosystem-based management approach promoted by forest ecologists, aimed at maintaining landscape stand composition and structures similar to those characterizing natural environments, will not be easily achieved. Forest ecosystems are highly dynamic and disturbances other than tree harvesting appear to have been the major factors affecting their pattern of change over the last three decades. Forest managers should consider adaptive management approaches that will consider the contemporary evolution of forest ecosystems in a changing environment.     

温湿度对昆嵛山腮扁叶蜂的影响

[目的]通过研究温度、降水量、温湿度系数与昆嵛山腮扁叶蜂种群动态变化的关系,探索气象因子对昆嵛山腮扁叶蜂发生的影响。[方法]在昆嵛山区选取7块标准样地,调查昆嵛山腮扁叶蜂发育期内的温度、降水量和相对湿度以及越冬蛹数量,然后统计分析温度、降水量、温湿度系数与昆嵛山腮扁叶蜂种群动态变化的关系。[结果]昆嵛山腮扁叶蜂在生活史的不同阶段所需的温度不同。6、7月份较高的降水量有助于昆嵛山腮扁叶蜂产卵和孵化,较低的降水量有利于其下树入土。同一样地的昆嵛山腮扁叶蜂越冬蛹的数量在不同年份中差异极显著(P<0.001);且所有样地的越冬蛹总量和虫口密度也均达到极显著水平(P<0.001)。昆嵛山腮扁叶蜂的虫口密度与发育期降水量和温湿度系数的年份变化趋势一致,但与温度的年份变化趋势不一致。2011年较低的温度、较高的降水量和温湿度系数造成了昆嵛山腮扁叶蜂的越冬蛹数量增多。[结论]低温高湿环境适合昆嵛山腮扁叶峰越冬蛹的生活。气象因子在调控昆翕山腮扁叶蜂的发生方面起着重要的作用,其为森林有害生物生态调控机制的重要组成部分。     

Simulation of Landscape Pattern of Old Growth Forests of Korean Pine By Block Kriging

IntroductionLandscapecanbeconsideredaspatiaI1yheterogeneousarea,andspatialpatter11referstothearra11gementofstructurall1eterogeneityofenvironments,resourceandbiologicalsysteInsinspace(Formanetall986,Tur11erl987,l989-Risserl987,TurneretaI199l).Turner(1987,1…