应用趋势分析建立蔡家营矿床的物性分布模式

在河北蔡家营铅锌银矿区有代表性的Ｖ矿带，选取了一条钻探剖面，作物性研究。采集了３１２块标本，测试了磁化率、剩余磁化强度及密度等物性参数；结合地面重磁测量，用趋势分析方法，建立该矿床物性分布模式，为本区建立综合地质—地球物理分布模型提供了物性依据。

Climatic niche shift of an invasive shrub (Ulex europaeus): a global scale comparison in native and introduced regions

Aims Invasive species,which recently expanded,may help understand how climatic niche can shift at the time scale of the current global change.Here,we address the climatic niche shift of an invasive shrub(common gorse,Ulex europaeus)at the world and regional scales to assess how it could contribute to increasing invasibility.Methods Based on a 28187 occurrences database,we used a combination of 9 species distribution models(SDM)to assess regional climatic niche from both the native range(Western Europe)and the introduced range in different parts of the world(North-West America,South America,North Europe,Australia and New Zealand).Important Findings Despite being restricted to annual mean temperature between 4℃ and 22℃,as well as annual precipitation higher than 300 mm/year,the range of bioclimatic conditions suitable for gorse was very large.Based on a native versus introduced SDM comparison,we highlighted a niche expansion in North-West America,South America and to a lesser degree in Australia,while a niche displacement was assessed in North Europe.These niche changes induced an increase in potential occupied areas by gorse by 49,111,202 and 283%in Australia,North Europe,North-West America and South America,respectively.On the contrary,we found no evidence of niche change in New Zealand,which presents similar climatic condition to the native environment(Western Europe).This study highlights how niche expansion and displacement of gorse might increase invasibility at regional scale.The change in gorse niche toward new climatic conditions may result from adaptive plasticity or genetic evolution and may explain why it has such a high level of invasibility.Taking into account the possibility of a niche shift is crucial to improve invasive plants management and control.

Study on Distribution Pattern of Plant Diversity of Forest Vegetation in Luofu Mountain,Guangdong

Through sample plot survey and statistic analysis,this paper adopts ecological method to study the characteristics of plant diversity of forest vegetation in Luofu Mountain,Guangdong.The results show that there is a great plant diversity of forest vegetation in Luofu Mountain owing to the ascendancy of aqueous and thermal condition in subtropical zone.The total number of species in 4 500 m2 sample plot(s)are 170 with 3 870 individual plants in total;Dahl species richness index(D)is 44.932;Simpson diversity index(L,D)is 0.022,0.022;Simpson(1982)diversity index(D)is 3.806;Pielou evenness index(E)is 0.984 and Hulbert evenness index(E)is 0.815;Shannon-wiener diversity index(information index H')is 4.188;Asymmetry index(r)is 0.185.These indexes show that a better habitat will bring about plant diversity of forest vegetation,and the diversity of zonal vegetation shows that the higher latitude is,the less species of vegetation can be found.Besides,vertical change of plant diversity of forest vegetation in Luofu Mountain is obvious.Its species richness index and plant diversity index show that monsoon evergreen broad-leaved forest is the tallest,mountain evergreen broad-leaved forest follows as the second and conifer-broad-leaved mixed forest is the shortest.The Wilson β-diversity index,which is obtained by comparison between forest vegetation below 300 m and forest vegetation between 600-900 m,is 0.621.Calculated from comparison between forest vegetation in 600-1 100 m and forest vegetation in 900-1 100 m,the Wilson β-diversity index is 0.727;by comparing forest vegetation below 300 m with forest vegetation in 900-1 100 m,the Wilson β-diversity index is 1.877.This shows that the plant diversity of forest vegetation is affected by the change in gradient of elevation.