Some developmental differences inEpinotia granitalis (Lepidoptera: Tortricidae) between two host tree species

To detect developmental differences inEpinotia granitalis in two host tree speciesCryptomeria japonica andChamaecyparis obtusa, the fourth or fifth instar larvae were collected daily from the two species located on the grounds of the National Forest Tree Breeding Center, from April 19 to May 9 in 1994 and April 18 to May 10 in 1995. Larvae ofE. granitalis collected fromC. obtusa had heavier body weight, developed to larger adults than those collected fromC. japonica, and mortality from the fourth or fifth instar larval stage to adults onC. obtusa was lower than that onC. japonica. All these facts suggest that larval performance onC. obtusa was higher than that onC. japonica.     

甜槠群落主要种群空间分布格局对人为干扰的响应

研究了不同人为干扰强度对甜槠天然群落中主要种群甜槠和赤楠的分布格局的变化动态.结果表明,人为干扰会使甜槠种群的聚集性加强,而赤楠种群的聚集性降低.干扰强度对甜槠聚集性的影响随树龄的增大而逐渐减小,而对赤楠聚集性的影响则是随林龄增大呈现由小→大→小的规律.     

云南松毛虫越冬代幼虫自然种群空间分布型的研究

通过样方调查计算，采用聚集度指标法，测定云南松毛虫越冬代幼虫的空问分布型，建立了最适抽样数关系式，并对其进行了序贯抽样分析。结果表明：云南松毛虫越冬代幼虫种群在林内呈聚集分布，其Iwao回归方程为m*=5．2181 1．0207x^-、复相关系数R=0．9918；最适抽样株数为：N=621．81/x^- 2．07。     

影响松毛虫赤眼蜂种群消长因子研究

１９８６－１９９０年的研究得知：松毛虫赤眼蜂在浙江于３月下旬开始活动，１０月上旬至１１月陆续以蛹在马尾松毛虫、云南松毛虫等虫卵中越冬在林中常年都可见到该蜂的活动，其种群数量出现的高峰期与松毛虫卵期相一致，林中昆虫卵的多少、蜜源植物的有无、温度的高低、是影响松毛虫赤眼蜂林间种群消长的主要因子。     

Genetic diversity of Populus euphratica populations in northwestern China determined by RAPD DNA analysis

Five Populus euphratica Oliver populations in northwestern China were analyzed using RAPD DNA markers to determine genetic diversity among and within populations. One hundred-and-five polymorphic bands were observed, ranging in size from 250 bp to 1700 bp, using 10 primers. Only one population on the north side of the Tianshern Range had a unique band common to all individuals that was not found in individuals from populations in the Tarim River valley. Intra-population genetic diversity was high in two populations along the Tarim River and low in the other three populations. There was no significant correlation between genetic distances and geographic distances. The result of correspondence analysis shows that the individuals from the three populations with low genetic diversity are isolated from each other. The result of cluster analysis based on genetic distance shows that the population in the Tianshern Range is genetically distant from the other populations. These results suggest that the Tianshern Range population was genetically isolated from the other populations.     

Spatial structure of genetic variation within populations of forest trees

The spatial pattern and structure of genetic variation are important aspects of the population genetics of forest stands. Combined with limits to seed and pollen dispersal, spatial structure affects the level of inbreeding and the action of natural selection. The genetic constitution of stand regeneration, following different forestry practices, is also influenced by spatial structure. For example, natural regeneration with seed trees involves sampling seed trees from a stand that may be genetically nonhomogeneous. This paper reviews theoretical and empirical results on spatial patterns of genetic variation, produced under limited gene flow and selection, in terms of recently developed spatial statistics (e.g., spatial autocorrelation). Genetic correlations in samples from spatially structured populations are also described, as well as how spatial samples can be used to characterize the structure of genetic variation, and how inferences can be made about (spatially distributed) components of fitness and yield.     

物种或种群生态位宽度与生态位重叠的计测模型

提出生态位宽度和生态位重叠的新定义及其若干测度模型.对不同学者提出的许多测度生态位宽度和生态位重叠的模型进行分析和评述.迄今为止,在国内限于单一生态资源轴上的生态位参数计测研究很多,随着多维生态位计测方法的不断发展,物种或种群在多维生态空间内的生态位宽度和生态位重叠计测,将备受关注.     

Spatial distribution pattern and dynamics of the primary population in a natural Populus euphratica forest in Tarim Basin, Xinjiang, China

One 50 m × 50 m standard plot was sampled in a natural forest of Populus euphratica in Awati County, situated at the edge of the Tarim Basin, Xinjiang Uygur Autonomous Region, China. The field investigation was conducted with a contiguous grid quadrate method. By means of a test of variance/mean value ratio, aggregation intensity index and theoretical distribution models, the spatial distribution pattern and the dynamics of primary populations in P. euphratica forest were studied. The results showed that the spatial distribution pattern of two dominant arbor populations conformed to clumped distribution. The aggregation intensity of the P. euphratica population was higher than that of P. pruinosa population. The spatial distribution pattern of two companion plant populations in the shrub layer also conformed to clump type, though the aggregation intensity of Tamarix chinensis was higher. In the herb layer, the distribution patterns of Glycyrrhiza uralensis and Asparagus persicus conformed respectively to a clumped pattern and a random pattern. The results of a Taylor power method test and Iwao’s regression model also verified that both P. euphratica and P. pruinosa populations belong to a clumped pattern. Although the distribution pattern of P. pruinosa population at different development stages all belonged to a clumped distribution pattern, the aggregation intensity dropped gradually along with age development. The distribution patterns of the P. euphratica population at different development stages changed from random type to clumped type, and further to random type. The differences in spatial distribution patterns of different populations at different development stages were related not only to ecological and biological characteristics of each species in the communities in the light of competitive exclusion principle among the populations, but were also closely related to the habitats in which the species lived in. __________ Translated from Journal of Southwest Forestry College, 2007, 27(2): 1–5 [译自: 西南林学院学报]     

方正智绘Mirage GIS在资源调查上的二次开发

论述了方正智绘Mirage GIS在森林资源调查中的二次开发,详细介绍了方正智绘MirageGIS进行二次开发的对象模型,方法,并在Visual Basic开发环境下进行具体实例的开发应用。     

竹盲走螨、胡瓜钝绥螨对毛竹害螨的控制作用研究

应用实验种群生命表数据分析毛竹林本土优势种竹盲走螨和引进种胡瓜钝绥螨对毛竹4种害螨南京裂爪螨、竹裂爪螨、竹缺爪螨、竹刺瘿螨的控制能力。结果表明①胡瓜钝绥螨取食上述4种害螨的世代存活率分别为90．4％、77．55％、87．93％、81．63％，每雌总产卵量分别为38．12粒、45．77粒、35．59粒、30．26粒，而乡土优势种竹盲走螨取食上述4种害螨的世代存活率分别为95．23％、100％、87．7％、80．48％，每雌总产卵量分别为44．5、46．8、41．15、20．1粒；②竹盲走螨以南京裂爪螨为猎物时其内禀增长率(0．155)与引进种胡瓜钝绥螨(0．154)相近，均明显高于南京裂爪螨(0．1089)；③竹盲走螨以竹裂爪螨为猎物其内禀增长率(0．152)与胡瓜钝绥螨(0．152)相同但明显低于竹裂爪螨(0．192)；④竹盲走螨以竹缺爪螨为猎物时其内禀增长率为(0．148)明显低于引进种胡瓜钝绥螨(0．175)和其猎物(0．185)；⑤竹盲走螨取食竹刺瘿螨易大量逃跑，雌螨产卵量低，引进种胡瓜钝绥螨取食竹刺瘿螨能正常生长发育，但是其内禀增长率(0．144)明显低于其取食上述其余3种害螨的内禀增长率，产卵量高于当地种竹盲走螨，并描述1998年以来每年5—6月助迁人工繁殖的胡瓜钝绥螨控制毛竹害螨蔓延的效果。