红脂大小蠹种群空间格局地统计学分析及抽样技术

红脂大小蠹是我国一重要林业外来入侵害虫,主要危害油松、白皮松和华山松,目前已扩散到山西、陕西、河北、河南、北京等地。为了研究其种群空间格局,用地统计学方法分析了受害程度不同的油松纯林和混交林林分内红脂大小蠹种群空间分布特性。结果表明:两种受害程度不同的油松纯林内红脂大小蠹的危害具有显著差异,轻度受害林分内有虫株率为4.9%,而重度受害林分则达到23.6%。全方向的变异函数曲线图分析得知:轻度受害纯林、重度受害纯林、混交林林分内红脂大小蠹种群的空间依赖范围分别为49.400、47.400\,73.820m,而局部空间连续性强度分别为0.824、0.582\,0.762。轻度受害纯林与重度受害纯林林分内红脂大小蠹种群均表现为较强的空间聚集性,而混交林受害林分内其种群则表现为随机分布。受害程度不同的纯林林分内红脂大小蠹种群空间格局具有一定的差异,而且纯林与混交林林分内其种群空间格局也有较大的差别。本文根据红脂大小蠹种群空间分布特性,对其种群空间抽样技术与传统抽样技术做了相应的比较与探讨。     

云南松林两种切梢小蠹成虫蛀梢期的空间分布格局

【目的】云南松Pinus yunnanensis Faranch是我国西南地区的重要造林绿化树种。近年来,云南省祥云县云南松林受到云南切梢小蠹Tomicus yunnanensis KirkendallFaccoli和横坑切梢小蠹Tomicus minor Hartig的共同危害。本文对两种害虫在蛀梢期的危害特性和空间分布进行了研究,以期为切梢小蠹的发生监测及防治提供依据。【方法】利用地统计学方法分析不同受害程度云南松林内两种切梢小蠹成虫蛀梢期的空间分布特性。【结果】受害程度不同的云南松林内两种切梢小蠹的危害差异显著,轻度受害林分内受害梢率为11.38%,中度受害林分内受害梢率为36.56%,而重度受害林分则达到59.7%。分析全方向的变异函数曲线图得知,蛀梢期两种切梢小蠹在不同受害云南松林中均呈聚集分布。其中,两种切梢小蠹在不同受害林分中空间依赖范围依次是:轻度受害林分中度受害林分重度受害林分,而局部空间连续性依次是:轻度受害林分中度受害林分重度受害林分。【结论】云南松林两种切梢小蠹成虫在蛀梢期的空间分布格局为聚集分布,明确两者在该时期存在聚集危害的特性,导致云南松因树梢受到聚集危害变为衰落木,从而有利于成虫蛀干危害和繁殖。本文为探究两种切梢小蠹在云南松林中的危害机制提供理论基础,也为虫害监测及防治提供参考与技术支持。     

褐梗天牛幼虫和成虫空间分布的地统计学研究

褐梗天牛(Arhopalus rusticus Linnaeus)是一种对松、杉、柏等林木危害非常严重的蛀干害虫,主要危害针叶树的衰弱木以及火灾后的枯立木,是继松褐天牛之后携带拟松材线虫能力最强的蛀干害虫。为了更好地控制其危害,深入地研究其种群空间格局,运用地统计学方法分析了3块受害程度不同的油松林内褐梗天牛幼虫和成虫的空间分布特性。结果表明:3种受害程度不同的林分内,褐梗天牛的危害具有显著差异,轻度受害林分内有虫株率为30.8%,中度受害林分内有虫株率为44.3%,而重度受害林分内高达78.3%。根据变异函数曲线图分析得知:轻度受害林、中度受害林和重度受害林内褐梗天牛幼虫种群空间分布最优拟合模型分别为高斯模型、高斯模型和指数模型,成虫的种群空间分布最优拟合模型均为线性模型。在3种林分中褐梗天牛幼虫数量具有明显的空间依赖性,轻度受害林、中度受害林和重度受害林内幼虫数量的空间依赖范围分别是19.10、11.97、61.98m,其空间连续性强度分别是0.646、0.784和0.500;成虫的空间依赖范围分别是43.08、43.23、44.17m,其空间连续性强度分别是0.044、0.021和0.171,但其成虫的数量在空间呈随机分布,没有表现出空间依赖性。根据垂直分布图分析得出:褐梗天牛幼虫和成虫在油松上主要集中聚集在某个高,然后随着高度增加密度降低,随着高度接近地面密度也降低。用Kriging插值法生成的空间分布图显示幼虫在空间分布上具有明显的聚集性,其聚集中心主要集中在林地中心,由林地中心株向整个林地扩散,而成虫则表现为随机分布。     

沙棘木蠹蛾蛹的空间分布

沙棘木蠹蛾（Holcocerus hippophaecolus Hua, Chou , Fang et Chen）是近几年在内蒙古、辽宁、山西、宁夏和陕西等地大面积爆发的一种钻蛀性害虫,该虫约4a完成1代,主要以幼虫危害沙棘（Hippophae rhamnoidea）的根部和干部,老熟幼虫在土壤中化蛹.为了解种群的空间结构,从而有效控制其危害,应用生物学统计方法和地质统计学（Geostatistics）方法对沙棘木蠹蛾蛹的空间分布特性进行了分析研究.结果表明：约90%的蛹在6月初到7月末之间羽化,而7月份羽化的数量占总数的一半之多.在调查样地中,雌雄蛹的比例基本为1：1.每株沙棘树周围,蛹的数量为0～4个,有蛹株率仅为24.3%.蛹在距离根基部周围1.3m的范围内均有分布,不同分布区间内蛹的数量变化没有一定的规律性,但90%的蛹分布在距根基部1m的范围内.沙棘木蠹蛾蛹的种群呈现较明显的空间聚集状态,空间依赖范围大小为11.1m,局部空间连续性强度为90.7%,呈现较明显的斑块状分布,在整个区域内有很多聚集点.对不同样方大小的变异曲线图进行比较得知：样方边长分别为5、6、7m时,变程、空间局部连续性强度和基台值的变化幅度均很小,几乎相等,而样方边长为5m时的决定系数较大,此样方为最适样方大小.     

沙棘主要蛀干害虫种群生态位

沙棘木蠹蛾(H olcocerus h ipp ophaecolusHua,Chou,F ang et Chen)是近几年在我国内蒙古、辽宁、山西、宁夏、陕西和甘肃等地大面积爆发的一种钻蛀性害虫,主要以幼虫危害沙棘(H ipp ophae rham noid ea)的根部和干部。在宁夏,沙棘除受到沙棘木蠹蛾的危害,还受到红缘天牛(A sias ha lod end ri Pa llas)的严重危害,该虫主要危害沙棘的干部。作者根据种群生态位理论,从时间、空间等资源利用上,定量地描述了沙棘木蠹蛾与红缘天牛种群之间的联系和竞争共存机制,结果表明:沙棘木蠹蛾幼虫主要分布在根部和干部80~120cm的范围内,不同时期,幼虫具有从干部向根部转移危害的习性;而红缘天牛主要分布在干部40~120cm的范围内,不同时期,幼虫没有转移危害的习性。沙棘木蠹蛾和红缘天牛的时间生态位和空间生态位宽度均较大,发生期较长,在沙棘上的活动范围较广,而不同时期内沙棘木蠹蛾的空间生态位宽度变动较红缘天牛大,其在沙棘上的活动范围在不同时期有较大的变动,而红缘天牛则较小。空间生态位重叠较小,在沙棘上的分布趋于分离,对空间资源的需求具有较大的差异,而时间生态位重叠较大,在沙棘的生长季节均能同时危害,危害期长但不具有明显的危害高峰期。两种害虫在空间生态位上的种间竞争强度较小,而在时间生态位上的种间竞争强度较大,在整个发生期内,两种害虫均能同时危害沙棘,但其位置有较大差异,在沙棘根部和干部40cm范围内,两种害虫几乎不能共存。     

云南松三种同域共存切梢小蠹梢转干期的空间分布格局

分布在我国西南地区的横坑切梢小蠹,云南切梢小蠹和短毛切梢小蠹同域危害寄主云南松,给林业生产带来巨大损失。为探讨同域切梢小蠹种群在共存下对其空间分布格局的影响,采用传统聚集指标法和地统计学方法研究了三者在梢转干期不同受害云南松纯林树冠中的空间分布型。结果表明重度受害样地中云南切梢小蠹种群密度显著高于横坑切梢小蠹,在轻度受害样地则相反;传统聚集指标法结果显示同域共存的3种切梢小蠹种群在不同受害程度云南松中均为聚集分布,横坑切梢小蠹和云南切梢小蠹聚集是由环境因素和昆虫本身的聚集习性引起;地统计学结果表明除重度受害样地中短毛切梢小蠹呈随机分布外,其余切梢小蠹在不同种群密度下均呈聚集分布;除重度受害样地横坑切梢小蠹外,其他小蠹的空间依赖范围为4.01—7.45 m。横坑切梢小蠹和云南切梢小蠹在不同受害林分中拟合的半变异函数模型在球形模型和高斯模型之间转换。同域共存关系不影响不同种群密度下的切梢小蠹种群空间分布类型,但影响其半变异函数模型和理论参数。     

沙棘灌丛林受害程度的预测模型

我国沙棘灌丛林目前的灾害可分为生物灾害和非生物灾害。生物灾害以沙棘木蠹蛾危害为主,是近几年在内蒙古、辽宁、山西、宁夏和陕西等地大面积爆发的一种钻蛀性害虫;非生物灾害主要是立地和气候因素,总体表现为沙棘生长衰退,甚至出现大面积枯死。对辽宁省建平县和内蒙古敖汉旗不同受害程度沙棘灌丛林进行抽样调查,共设50块标准地,分别调查沙棘死亡株率、有叶树冠比例、沙棘木蠹蛾危害株率和20cm根干部沙棘木蠹蛾虫口数等沙棘受害指标,同时调查记录坡向、坡位、坡度、树高、地径和林分密度等多项生跃环境因子。通过模糊综合评判法,对4种受害特征指标进行权重分配,并根据综合评判值的大小,将沙棘灌丛林的受害程度分为健康、轻、中和重4个等级,以坡向、坡位、坡度、树高、地径和林分密度为预测因子,分别构建沙棘灌丛林受害程度BP神经网络模型和Logistic模型,BP神经网络的拟合率达88．1％,预留样本检验准确率为75％,Logistic模型的概率一致率为69．4％。在其它条件相同的情况下,坡位对受害程度的影响是其它因素的4．93倍。     

沙棘木蠹蛾的幼虫空间分布与抽样技术

利用常用的聚集度指标 ,对沙棘木蠹蛾HolcocerushippophaecolusHua ,Chou ,FangetChen幼虫的分布进行了分析。结果显示 ,该幼虫的空间分布格局为聚集型分布。通过Iwao的m - x回归检验方程 ,确定了其最适抽样数和最佳样方大小。采用对角线、之字型、五点式、棋盘式和平行线等 5种抽样方法对沙棘木蠹蛾幼虫的抽样技术分别进行了研究 ,结果表明 :最佳的抽样方法为棋盘式。     

马尾松毛虫空间格局的地学统计学分析

应用地学统计学方法分析了湿地松 马尾松 火炬松林中马尾松毛虫越冬代蛹、第一代卵块和低龄幼虫的空间格局 .结果表明 ,蛹在 0°、45°、90°、1 35°4个方向上的半变异函数曲线为球形 ,在 90°方向上的空间连续性大于其他方向 ;卵块和低龄幼虫的为指数形 ,在各方向上无差异 .蛹、卵块和幼虫在全方向上的半变异函数曲线均为球形 ,呈聚集型的空间格局 ,聚集强度以蛹最高 ,依次是幼虫和卵块 .分别拟合了蛹、卵块和幼虫的半变异函数模型 ,估算了样地各处的密度 ,绘制了密度等值线图     

栎黄枯叶蛾低龄幼虫空间分布的地统计学分析

栎黄枯叶蛾(Trabala vishnou gigantina Yang)是近年在陕西吴起发现的严重危害沙棘的一种食叶害虫。为了准确把握栎黄枯叶蛾幼虫的分布规律,以便对该虫的危害盛期进行预测预报和采取防治措施,因而采用地统计学分析方法对不同坡向和疏密度的沙棘林中栎黄枯叶蛾低龄幼虫的空间分布格局进行了研究。结果表明:栎黄枯叶蛾卵孵化高峰期为6月中旬。通过全方向的变异函数曲线分析得知:阴坡密林、阴坡疏林、阳坡密林、阳坡疏林中,栎黄枯叶蛾低龄幼虫空间依赖范围分别为19.96、9.45、20.75、13.48 m,空间变异值分别为0.692、0.613、0.679、0.597。密林样地的半变异函数最佳拟合模型均为高斯模型,疏林样地均为指数模型,两种模型均指明栎黄枯叶蛾低龄幼虫的空间分布格局为聚集分布。引起种群聚集的原因主要为其生物学特性。用Kriging插值方法生成的空间分布图显示低龄幼虫在空间分布上存在明显的边缘效应。     

Spatial distribution of Holcocerus hippophaecolus (Lepidopetera: Cossidae) pupae in a seabuckthorn (Hippophae rhamnoides) stand.

The seabuckthorn carpenter moth,Holcocerus hippophaecolus,which has a generation time of four years,is recently becoming one of the major pests of the seabuckthorn (Hippophae rhamnoides) in Inner Mongolia,Liaoning,Shanxi,Ningxia and Shaanxi of China (Hua et al.,1990).The larvae of the H.hippophaecolus mainly damage the stems and roots of the seabuckthorn,and the mature larvae pupate in the soil.The spatial distribution of the pupae was analyzed by using biostatistics and geostatistics in order to effectively control the insect and further study the spatial distribution of the population.Results show that most of the pupae (90%) had an eclosion time span from early June to the end of July.The sex ratio of the pupae was nearly 1:1 in the woodland samples.In addition,24.3% of the 971 trees investigated had pupae and it ranged from 0 to 4 per tree within a distance of 1.3 m from the base of the stem.90% of the pupae were aggregated within a distance of 1 m from the base of the stem.The pupae show intense spatial aggregation in the sampled woodland which had an 11.1 m spatial dependence and a 90.7% intensity in the local spatial continuity.Moreover,the population presented an intensive spotted distribution and many aggregated spots were found in the woodlands.As for the relationship between grid size and variogram of the pupae,the variations in the range,the intensity of local spatial continuity and the sill were all very low or non-existent when the grid size was 5 m,6 m or 7 m.Whereas,the value of the decisive coefficient was the biggest when the grid size was 5 m making it the ideal grid size.     

Spatial distribution of Holcocerus hippophaecolus (Lepidoptera: Cossidae) pupae in a seabuckthorn (Hippophae rhamnoides) stand

The seabuckthorn carpenter moth, Holcocerus hippophaecolus, which has a generation time of four years, is recently becoming one of the major pests of the seabuckthorn (Hippophae rhamnoides) in Inner Mongolia, Liaoning, Shanxi, Ningxia and Shaanxi of China (Hua et al., 1990). The larvae of the H. hippophaecolus mainly damage the stems and roots of the seabuckthorn, and the mature larvae pupate in the soil. The spatial distribution of the pupae was analyzed by using biostatistics and geostatistics in order to effectively control the insect and further study the spatial distribution of the population. Results show that most of the pupae (90%) had an eclosion time span from early June to the end of July. The sex ratio of the pupae was nearly 1:1 in the woodland samples. In addition, 24.3% of the 971 trees investigated had pupae and it ranged from 0 to 4 per tree within a distance of 1.3 m from the base of the stem. 90% of the pupae were aggregated within a distance of 1 m from the base of the stem. The pupae show intense spatial aggregation in the sampled woodland which had an 11.1 m spatial dependence and a 90.7% intensity in the local spatial continuity. Moreover, the population presented an intensive spotted distribution and many aggregated spots were found in the woodlands. As for the relationship between grid size and variogram of the pupae, the variations in the range, the intensity of local spatial continuity and the sill were all very low or non-existent when the grid size was 5 m, 6 m or 7 m. Whereas, the value of the decisive coefficient was the biggest when the grid size was 5 m making it the ideal grid size.     

Spatial distribution of Holcocerus hippophaecolus (Lepidoptera: Cossidae) pupae in a seabuckthorn (Hippophae rhamnoides) stand

The seabuckthorn carpenter moth, Holcocerus hippophaecolus, which has a generation time of four years, is recently becoming one of the major pests of the seabuckthorn (Hippophae rhamnoides) in Inner Mongolia, Liaoning, Shanxi, Ningxia and Shaanxi of China (Hua et al., 1990). The larvae of the H. hippophaecolus mainly damage the stems and roots of the seabuckthorn, and the mature larvae pupate in the soil. The spatial distribution of the pupae was analyzed by using biostatistics and geostatistics in order to effectively control the insect and further study the spatial distribution of the population. Results show that most of the pupae (90%) had an eclosion time span from early June to the end of July. The sex ratio of the pupae was nearly 1:1 in the woodland samples. In addition, 24.3% of the 971 trees investigated had pupae and it ranged from 0 to 4 per tree within a distance of 1.3 m from the base of the stem. 90% of the pupae were aggregated within a distance of 1 m from the base of the stem. The pupae show intense spatial aggregation in the sampled woodland which had an 11.1 m spatial dependence and a 90.7% intensity in the local spatial continuity. Moreover, the population presented an intensive spotted distribution and many aggregated spots were found in the woodlands. As for the relationship between grid size and variogram of the pupae, the variations in the range, the intensity of local spatial continuity and the sill were all very low or non-existent when the grid size was 5 m, 6 m or 7 m. Whereas, the value of the decisive coefficient was the biggest when the grid size was 5 m making it the ideal grid size. __________ Translated from Acta Ecologica Sinica, 2006, 26(10): 3232–3237 [译自: 生态学报]     

Spatial distribution and sampling plans for Mesoplatys ochroptera (Coleoptera: Chrysomelidae) on sesbania

With the widespread introduction of the nitrogen-fixing legume sesbania, Sesbania sesban (L.) Merril, in agroforestry systems, the defoliating beetle Mesoplatys ochroptera St?l has become a serious pest of the trees in Africa. To determine within-field and within-plant spatial distribution of M. ochroptera on both seedlings and trees of sesbania, distribution statistics were computed using Iwao's mean crowding regression model. In 1- to 3-mo-old seedlings, the model accounted for 29.8, 32.2, and 61.0% of the variation observed in mean crowding to mean relationships in egg masses, larvae and adults, respectively. The model slopes of the regression were greater than unity for all stages indicating aggregated spatial distribution. Values of the intercept were greater than zero for egg masses, larvae and adults indicating that the basic components of the population are groups of individuals. The highest density (>80%) of mating and feeding adults was found in the upper third of 1- to 2-mo-old seedlings, while most of the egg masses were found in the lower half of seedlings. In trees, >60% of the individuals of all stages were found in the lower third of the foliage canopy, while <10% were found in the upper third. Sampling adults was found to be easier and gave better density estimates of M. ochroptera population than egg masses and larvae. Therefore, sampling plans useful for population studies and decision-making in pest management were developed for adults.     

荒漠景观下柠条豆象的空间分布及其对景观斑块格局的反应

柠条豆象Kytorhinus immixtus Motschulsky是危害柠条种子的主要种实害虫之一。本文应用了多个聚集度指标和回归分析方法,研究探讨了柠条豆象卵、幼虫在宁夏盐池、灵武、银川等荒漠景观中11个生境斑块中的空间分布型及种群对景观斑块格局的反应情况。结果表明:在11个景观样地中,柠条豆象卵和幼虫在各种生境斑块中均呈聚集型的负二项分布;卵和幼虫空间分布的Iwao回归方程分别为m*=2.23695+1.64742m(r=0.8273)和m*=2.24418+1.42084m(r=0.8889)、Taylor幂模型分别为logS2=0.51292+1.41118logm(r=0.9344)和logS2=0.59645+1.14736logm(r=0.9786),种群分布的基本成分为个体群,个体间相互吸引,有密度依赖性,聚集主要由环境因素和种间竞争引起的,聚集强度随种群密度的升高而增加。在荒漠景观下,柠条豆象的种群发生与寄主植物的种类、在斑块内的分布格局有着密切的关系,与斑块面积相关性较低(R2=0.1995)。主成分分析显示柠条林生长的土壤类型、生长方式是影响柠条豆象寄生的主要因素。     

Scales of aboveground and below-ground competition in a semi-arid woodland detected from spatial pattern

Abstract. Semi-arid woodlands are two-phase mosaics of canopy and inter-canopy patches. We hypothesized that both aboveground competition (within canopy patches), and below-ground competition (between canopy patches), would be important structuring processes in these communities. We investigated the spatial pattern of trees in a Pinus edulis-Juniperus monosperma woodland in New Mexico using Ripley's K-function. We found strong aggregation of trees at scales of 2 to 4 m, which indicates the scale of canopy patches. Canopy patches were composed of individuals of both species. Crown centers of both species were always less aggregated than stem centers at scales less than canopy patch size, indicating morphological plasticity of competing crowns. In the smallest size classes of both species, aggregation was most intense, and occurred over a larger range of scales; aggregation decreased with increasing size as is consistent with density-dependent mortality from intraspecific competition. Within canopy patches, younger trees were associated with older trees of the other species. At scales larger than canopy patches, younger trees showed repulsion from older conspecifics, indicating below-ground competition. Hence, intraspecific competition was stronger than interspecific competition, probably because the species differ in rooting depth. Woodland dynamics depend on the scale and composition of canopy patches, aggregated seed deposition and facilitation, above- and below-ground competition, and temporal changes in the spatial scale of interactions. This woodland is intermediate in a grassland-forest continuum (a gradient of increasing woody canopy cover) and hence we expected, and were able to detect, the effects of both above- and below-ground competition.