油蒿不同演替阶段钻蛀性害虫数量变动与环境的关系

油蒿是我国北方农牧交错带的重要固沙植物,近年来受到油蒿钻蛀性害虫的危害,导致大面积死亡.2006年5月至2007年9月在宁夏盐池县对油蒿不同演替阶段的油蒿钻蛀性害虫混合种群的组成和数量变化及环境因子进行系统的调查,结果表明:危害油蒿的钻蛀性害虫分别是沙蒿大粒象、沙蒿木蠹蛾、沙蒿圆吉丁虫和一种蛀茎蛾(鳞翅目:卷蛾科);在油蒿不同演替阶段,上述4种油蒿钻蛀性害虫均有危害,且每个阶段的优势种各不相同;线性逐步回归分析表明油蒿钻蛀性害虫混合种群受油蒿林的演替阶段及油蒿群落的微环境影响较大.     

不同分布格局低覆盖度油蒿群丛防风效果

以低覆盖度(约20%)油蒿群丛为研究对象,采用多点式自记风速仪,研究行带式配置和随机分布的防风效果.结果表明:1)行带式配置的油蒿群丛的防风效果大于同覆盖度的随机分布的油蒿群丛,行带式配置具有显著的防风效果;2)在灌丛与灌丛之间形成的类似"狭管"流场的局部,有局部提升风速的作用,导致群丛内局部风速大于对照风速,致使随机分布的油蒿群丛内流场结构复杂、变化多样,低覆盖度时,沙地处于半固定、半流动状态,稀疏群丛内同时存在风蚀和积沙现象;3)除去两个极值后,行带式配置的油蒿群丛内平均地表粗糙度是随机配置的4倍,平均摩阻速度是随机配置的1.3倍,说明行带式配置具有显著的防止风蚀、固定流沙的作用.     

沙蒿、油蒿空间构件及固沙机制研究

油蒿和沙蒿同属菊科、蒿属的沙生半灌木，抗旱性强，生态幅宽，在沙区人工植被中可天然更新，是我国干旱沙区优良的固沙植物种。由于油蒿能够进行光合的部件远多于沙蒿且相对沙蒿能够更好地利用空间资源，在相同的时间内油蒿经光合沉积的生物量远大于沙蒿。受个体空间结构、生物量分配模式及种群整体特征的共同影响，在生存环境相同的情况下油蒿的个体及种群固沙效益要比沙蒿高。     

基于MSO方法的2个油蒿群落格局对比研究

应用多尺度排序法(multiscale ordination,简称为MSO),对乌兰布和沙漠东北缘黄河水与井水2种灌溉模式绿洲外围的半固定油蒿群落进行多种群格局对比研究。结果表明:在黄灌区,油蒿不仅是群落的优势种(重要值为45.26%),而且对植被格局的贡献率也最高;83.84%的植被形成了油蒿单种群格局,且油蒿贡献率高达0.889 6。在井灌区,植物种对格局的贡献率与其在群落中的重要值明显不一致:油蒿是群落的优势种(重要值为47.41%),但在植被格局中的贡献率明显下降,只有15.54%的植被形成了以油蒿为主的格局;沙冬青、白刺却相反,它们在植被格局中的贡献率远远高于其在群落中的重要值。对比2区段的其它格局特点还发现:井灌区油蒿群落植被的斑块化现象更严重一些,并且油蒿斑块内的格局强度低于黄灌区。     

平茬处理对油蒿群落冠层结构的影响

通过对库布齐沙漠的油蒿群落进行平茬处理,研究了平茬后油蒿群落冠层结构的变化。结果表明:在生长旺季7月和8月上旬,平茬油蒿的叶面积指数(LAI)显著高于未平茬油蒿的值(P0.05),反映出平茬处理后油蒿的叶面积指数增大,提高了光能利用能力;平茬油蒿群落的天空开度(DIFN)显著低于未平茬油蒿群落的值(P0.05),说明平茬处理有利于油蒿枝叶更新,使其新生枝叶的生长更为茂密。总的来说,平茬在一定程度上改善了油蒿群落的冠层结构,提高了油蒿群落对光能的利用率,有利于油蒿的生长。     

鄂尔多斯地区两种典型沙质荒漠化阶段微气象特征的比较研究

本文旨在研究鄂尔多斯地区的两种典型的沙质荒漠化阶段的下垫面微气象特征(净辐射、土壤水分、土壤温度、降水量、风速)的变异性规律与沙质荒漠化之间的关系。两种典型沙质荒漠化阶段的群落类型分别为油蒿群落和牛心朴子群落。结果表明，由于沙质荒漠化不同阶段的下垫面的植被群落组成、结构和盖度的差异，引起净辐射、土壤含水量、近地层风速等产生较大差异。油蒿群落的太阳净辐射能明显比牛心朴子群落高；油蒿群落与牛心朴子群落的不同深度土壤水分差别很大，当降雨量在45mm以下时，只能影响0—40cm土深的土壤水分状况，而这一深度恰好是大部分植物根系分布的区域。油蒿群落比牛心朴子群落更有利于维持土壤温度的恒定。油蒿群落对近地面风速有明显的削减作用。     

油蒿不同演替阶段钻蛀性害虫幼虫与天敌在空间格局上的关系

油蒿(Artemisia ordosica)钻蛀性害虫包括沙蒿圆吉丁虫(Sphenoptera sp.)(鞘翅目:吉丁虫科)、沙蒿大粒象(Adosopius sp.)(鞘翅目:象甲科)、沙蒿木蠹蛾(Holcocerus artemisiae)(鳞翅目:木蠹蛾科)和一种卷蛾科(Tortricidae)蛀茎害虫,主要分布于我国的内蒙古、陕西、宁夏、甘肃等省区(阎伟等,2009a;2009b),且有大面积暴发的趋势.它们主要以幼虫危害油蒿根和茎基部,在根茎内钻蛀隧道,破坏木质部而导致油蒿死亡.因其只在成虫期行裸露性生活,营隐蔽性生活时间很长,监测和防治都极为困难.油蒿是我国特有的优良固沙半灌木植物,亦称黑沙蒿,属菊科植物,是毛乌素沙地中分布最广泛的沙生植物群落的优势种,遍见于半固定与固定沙丘沙地,是沙地天然植物群落,具有耐沙埋、抗风蚀、耐贫瘠、分枝和结实性能好的特性,对毛乌素沙地系统的稳定起着关键作用(北京大学地理系等,1983;张新时,1994;杨洪晓等,2004;张德魁等,2007).目前对油蒿钻蛀性害虫的生物学和生态学方面的研究报道不多.宁夏盐池县油蒿钻蛀性害虫的主要天敌为寄生于幼虫的一种蒲螨(Pyemotes herfsi)(蒲螨科Pyemotidae)(马立芹等,2008)和啄开根部捕食幼虫及蛹的斑翅山鹑(Perdix dauuricae).为探讨合理有效的综合治理技术,2006-2008年在宁夏盐池县对4种油蒿钻蛀性害虫及其寄生性天敌蒲螨和斑翅山鹑啄痕的空间格局进行系统调查.     

乌兰布和沙漠东北部绿洲边缘2种天然植被特征研究

白刺(Nitraria tangutorum Bobr.)和油蒿(Artemisia ordosica Krasch)是乌兰布和沙漠东北部人工绿洲边缘常见的植物种,从植物群落及个体特征对此2种天然植被进行研究,结果表明:白刺群落和油蒿群落结构都比较简单,白刺群落环境优于油蒿群落;白刺的地上生物量显著高于油蒿(P<0.05),两者的基径、高度和冠幅之间没有显著差异(P>0.05);白刺的地上生物量与基径、高度之间存在显著的正相关性,而油蒿的各生长指标之间没有显著的相关性。     

鄂尔多斯高原油蒿灌丛群落生物量和净初级生产力研究(英文)

应用标准株收获法对鄂尔多斯高原油蒿灌丛群落生物量和净初级生产力进行了一个生长季(6月~10月)的研究。结果表明:(1)生长季内不同月份之间相同株型单株油蒿地上和地下生物量差异不显著(p>0.1),而地上当年生部分生物量差异显著(p<0.01);(2)油蒿群落中,地上和地下总生物量为699.76~1246.40gm-2,年地上部分NPP值为224.09 gm-2y-1;(3)单株油蒿生物量和 NPP 与灌丛体积具有较好的相关性,应用幂指数方程能够达到较好的拟合效果。     

黑沙蒿的优良特性与开发利用

一、黑沙蒿的分布 黑沙蒿,又名沙蒿、油蒿、鄂尔多斯蒿,分布范围跨越了典型草原、荒漠化草原和草原化荒漠3个自然带。据西北水土保持生物土壤研究所调查,沙蒿在西北和内蒙古西部地区分布面积达37,500万亩。     

Damage characteristics of three boring pests in Artemisia ordosica

The population density and distribution of the three major boring pests,Holcocerus artemisiae,Sphenoptera sp.and Adosopius sp.were studied in their host plant Artemisia ordosica.Results show that the larvae of H.artemisiae mainly bore the rhizome of A.ordosica,but also the larvae of Sphenoptera sp.and Adosopius sp.bore the rhizome of A.ordosica.The adults of Sphenoptera sp.and Adosopius sp.feed on the leaves of A.ordosica as a nutritional supplement.The distribution of the larvae of three pests in their hos...     

Damage characteristics of three boring pests in Artemisia ordosica

The population density and distribution of the three major boring pests, Holcocerus artemisiae, Sphenoptera sp. and Adosopius sp. were studied in their host plant Artemisia ordosica. Results show that the larvae of H. artemisiae mainly bore the rhizome of A. ordosica, but also the larvae of Sphenoptera sp. and Adosopius sp. bore the rhizome of A. tordosica. The adults of Sphenoptera sp. and Adosopius sp. feed on the leaves of A. ordosica as a nutritional supplement. The distribution of the larvae of three pests in their host plant is completely different. H. artemisiae and Sphenoptera sp. are distributed in the whole A. ordosica plant. The newly hatched larvae first feed on the phloem and xylem of stem and then burrow to the roots before the winter of the same year. However, Adosopius sp. is distributed mainly in the roots. The newly hatched larvae move from the phloem to the xylem, and gradually damage the lower part of the trunk. The larvae of the three pests sometimes coexist in a single A. ordosica plant. However, the probability of the coexistence of the three pests is very small. The highest probability of coexistence of two pests was observed in Sphenoptera sp. and H. artemisiae, while the probability of coexistence of Sphenoptera sp. and Adosopius sp. as well as H. artemisiae and Adosopius sp. was smaller. The reasons for coexistence or its avoidance are not only related to the amount of food provided nor the volume of larval living space in a single A. ordosica plant, but also related to the development characteristics of different kinds of larvae and interspecific competition.     

2种经营方式下早竹林虫瘿的空间分布研究

正早竹(Phyllostachys praecox C.D.Chu et C.S.Chao)别名早园竹(浙江德清),属禾本科(Gramineae)刚竹属(Phyllostachys Sieb.et Zucc)刚竹组(Sect.Phyllostachys),产于我国江苏、安徽、浙江、江西、湖南、福建等省[1-3]。早竹因其笋期早、产量高、笋味美,而成为我国南方的重要笋用竹种[1]。据统计,我国南方早竹的种植面积在6.7万hm2以上,年产值达10亿多元[4]。然而,随着早竹大面积的推广种植和新的生产经营方式的推广应用,早竹遭受造瘿昆虫的严重危害。在部分严重危害的地块,有虫株率     

松褐天牛肿腿蜂对松褐天牛低龄幼虫控制作用的研究

研究测定了松褐天牛肿腿蜂对松褐天牛1～3龄幼虫的控制作用,采用林间和室内罩网相结合的方法研究了2组松褐天牛肿腿蜂对松褐天牛幼虫的寄生情况.结果显示:在室内试验条件下,松褐天牛肿腿蜂产卵之前的刺蛰、补充营养取食能直接造成松褐天牛1～3龄幼虫死亡,对1、2及3龄幼虫的平均致死率分别为95.66％、85.91％、57.88％,并可产卵寄生2、3龄幼虫;林间释放2组松褐天牛肿腿蜂后,在刺蛰和补充营养取食后能有效寄生寄主的肿腿蜂雌蜂数量比例变化较大,有效肿腿蜂率最高为14.9％,最低为2.3％.松褐天牛肿腿蜂寄生行为不受寄主聚集程度的影响,但刚羽化出茧肿腿蜂雌蜂的寄生效率比经饲喂后的雌蜂高近5倍.从肿腿蜂单一个体来看,每头雌蜂补充营养取食和产卵寄生致死的松褐天牛幼虫数为2.1～7.7头.松褐天牛肿腿蜂雌蜂的补充营养习性及刺蛰、取食致死寄主行为在防治中有很重要的作用,表明该种肿腿蜂是防治松褐天牛的重要天敌,在生物防治松褐天牛幼龄幼虫上具有良好的应用前景.     

辣木人工林的主要害虫种类及其空间分布

对广东省梅州市梅江区西阳镇林林试验样地进行调查，初步掌握了辣木人工林为害害虫的 主要种类、发生规律以及空间分布。结果表明：辣木人工林主要害虫种类有含夜蛾 Prodenia litura、小 菜蛾 Plutella xylostella、赤斑白条天牛 Batocera rufomaculata、花蓟马 Frankliniella intonsa、稻管蓟马 Haplothrips aculeatus、斜纹夜蛾 Spodoptera litura 和茶蚜 Toxoptera aurantii 共 7 种；夜蛾与小菜蛾的发生 危害程度已达到重度危害水平，而花蓟马、稻管蓟马与茶蚜则达到中度危害水平，斜纹夜蛾与赤斑白条 天牛的危害程度则为轻度；主要害虫幼虫种群的发生为害高峰时间为 9 月，1 月 -3 月幼虫种群几乎不发 生为害，其余月份幼虫种群虫口密度较低；夜蛾、小菜蛾、花蓟马、稻管蓟马、茶蚜与斜纹夜蛾的幼虫 空间分布均呈均匀分布，而赤斑白条天牛幼虫呈聚集分布，聚集发生的原因是林间外界环境因子与其自 身生物学特性共同相互作用引起的。     

Long-term spatial dynamics of Acer saccharum during a population explosion in an old-growth remnant forest in Illinois

Species richness and evenness have greatly declined in oak–hickory forests in the central hardwood region in the U.S.A. in the past 100 years due to the rapid population growth of Acer saccharum. This study used a 50-year record of spatial dynamics to examine how demographic processes, particularly recruitment, may have contributed to this increase in an old-growth forest remnant, Brownfield Woods, Urbana, Illinois, U.S.A. The impact of canopy disturbance, including the outbreak of Dutch elm disease, on this increase was also evaluated. Historical maps of trees (≥7.6 cm DBH) from 1951, 1988, and 2001 in a 180 m × 280 m area were used to develop a series of univariate Ripley's L(d) functions to study changes in spatial patterns of three size classes of A. saccharum over time. Bivariate Ripley's L(d) functions were also utilized to evaluate spatial associations between recruitment and canopy disturbance. Our results indicated that A. saccharum was aggregated at most spatial scales up to 80 m during 1951–2001. Such aggregation arose mainly from small individuals. Furthermore, newly recruited individuals were aggregated at multiple spatial scales, and were significantly associated with canopy disturbance in general, as well as gaps created by Ulmus trees killed by Dutch elm disease. The aggregation of the 1951 initial group of small individuals changed via mortality to a random distribution over time. The results indicate that tree deaths caused by disturbances of different scales and types were the main cause of increased recruitment of A. saccharum in Brownfield Woods. The occurrence of Dutch elm disease further accelerated its population increase. This study demonstrated a direct spatial link between recruitment of A. saccharum and disturbance, and provided a long-term case study of a population explosion.     

深圳梅林仙湖苏铁的种群特征与保护研究

To study the population characteristics of Cycas fairylakea D. Y. Wang, a comprehensive field investigation was conducted with the help of GPS system. In this study, the quantitative characteristics and age structure of the genet were analyzed, and their distribution pattern and grow conditions were evaluated. In investigation, 1 013 C. fairylakea trees were found,which distributed in patch. Although the population scale and structure get better recovery,being limited by the topography and microclimate conditions, the growth conditions and natural proliferation ability of the population is still very fragile. To make C. fairylakea get rid of endangered status, it is proposed to establish a protection area for it and adopt necessary measures to promote the regeneration and development of the population.     

Multiscale spatial variation of the bark beetle Ips sexdentatus damage in a pine plantation forest (Landes de Gascogne,Southwestern France)

Bark beetles are notorious pests of natural and planted forests causing extensive damage. These insects depend on dead or weakened trees but can switch to healthy trees during an outbreak as mass-attacks allow the beetle to overwhelm tree defences. Climatic events like windstorms are known to favour bark beetle outbreaks because they create a large number of breeding sites, i.e., weakened trees and for this reason, windthrown timber is generally preventively harvested and removed. In December 1999, the southwest of France was struck by a devastating windstorm that felled more that 27 million m³of timber. This event offered the opportunity to study large-scale spatial pattern of trees attacked by the bark beetle Ips sexdentatus and its relationship with the spatial location of pine logs that were temporally stored in piles along stand edges during the post-storm process of fallen tree removal. The study was undertaken in a pure maritime pine forest of 1300 ha in 2001 and 2002. We developed a landscape approach based on a GIS and a complete inventory of attacked trees. During this study more than 70% of the investigated stands had at least one tree attacked by I. sexdentatus  . Spatial aggregation prevailed in stands with n≥15$n\ge 15$ attacked trees. Patches of attacked trees were identified using a kernel estimation procedure coupled with randomization tests. Attacked trees formed patches of 500–700 m² on average which displayed a clumped spatial distribution. Log piles stemming from the sanitation removals were mainly distributed along the large access roads and showed an aggregated spatial pattern as well. The spatial relationship between patches of attacked trees and log pile storage areas was analyzed by means of the Ripley’s statistic that revealed a strong association at the scale of the studied forest. Our results indicated that bark beetle attacks were facilitated in the vicinity of areas where pine logs were stored. The spatial extent of this relationship was >1000 m. Similar results were obtained in 2001 and 2002 despite differences in the number and spatial distribution of attacked trees. The presence of a strong “facilitation effect” suggests that log piles should be removed quickly in order to prevent outbreaks of bark beetles.     

海南岛尖峰岭卵叶樟种群结构与分布格局动态研究

卵叶樟(Cinnamomum rigidissimum H. T. Chang)是樟科(Lauraceae)樟属(Cinnamomum Trew)植物,是第一批被列入<国家重点保护植物名录>的二级重点保护物种[1],具有重要的经济和科研价值.根据以往调查,卵叶樟在海南尖峰岭的数量较少,一般生长在海拔6001 000 m的热带山地雨林中,这与森林商业性采伐和盗伐等人为干扰活动导致森林环境变迁有关[2-3].种群是群落构成的基本单位,种群结构不仅对群落结构有直接影响,而且能客观地体现群落的发展趋势[4].研究种群空间格局及其动态可为研究森林群落演替趋势、森林生态系统可持续经营提供基础理论,其数量分析指数还可为生物多样性保护、森林可持续经营评价等提供可靠依据[5].本文通过探讨卵叶樟种群结构和分布格局及其动态的数量特征,为探讨其濒危机制及合理保护提供理论依据.     

樟子松梢斑螟幼虫空间分布型研究

为了研究樟子松梢斑螟(Dioryctria mongolicella)幼虫在樟子松栽植区的空间分布格局和抽样技术,并为该虫的野外调查与防治提供理论依据,采用8个聚集度指标和3种回归分析法对樟子松梢斑螟幼虫的空间分布型进行测定。同时,通过Iwao回归法计算了樟子松梢斑螟幼虫种群的最适抽样量并拟合序贯抽样模型。结果表明,樟子松梢斑螟的8个聚集度指标均显示为聚集分布,分布的基本成分是种群,且个体之间相互吸引。随着田间平均虫口密度的增大,抽样数逐渐减少;随着允许误差逐渐减小,所需要的抽样数就越大。建立的序贯抽样表和最适抽样量表可在林间调查中应用。