蚱蝉成虫的空间格局研究

蚱蝉成虫在其产卵危害林内不同时期及日不同时刻的分布均为聚集分布。其聚集度在一日之内随温度的升高而降低，在不同时期随密度和龄期的增大而增强。     

祁连山浅山区金露梅群落种间关系及其分布格局

通过对祁连山浅山区金露梅群落特征、种间关系及分布格局的分析 ,结果表明 :浅山区金露梅群落相对重要值为 10 4 .2 8% ,频度为 92 .0 0 % ,为主要优势种 ;群落内种间关系关联性不强 ,分布状况受环境条件影响而独立地分享环境资源 ,种群间相互影响小 ;经各种群分布格局的检验 ,祁连山浅山区大多数种群呈聚集分布 ,有利于种群的生存和发展。     

Distribution of Aeolothrips intermedius Bagnall (Thysanoptera: Aeolothripidae) and its potential prey Thysanoptera species on different cultivated host plants

The results of the monitoring of Thysanoptera species on cultivated plants in Slovenia (2000–2001), Croatia (1994–1996), and Serbia and Montenegro (1988–2003) are presented in this study. The aim of the investigation was to study the host plant distribution of the predator Aeolothrips intermedius Bagnall and its potential prey. Banded thrips were found on 30 different host plant species belonging to 16 botanical families, always in mixed populations with phytophagous or facultative phytophagous insects (including 18 Thysanoptera species). On the vegetative parts of the cultivated plants, banded thrips were found less numerous in spite of the massive population of some harmful thrips species. This indicates highly important role of pollen as alternative food for Aeolothrips intermedius.     

张家沟集水区林木竞争指数空间分布的探讨

对张家沟集水区内的树木,运用Visual foxpro编写程序计算树木的竞争指数,并对树木所受到的竞争强度的平均值进行统计,根据结果分析树木竞争指数的分布格局。     

矮杨梅生境及群落学特征

矮杨梅（Myrica nana Cheval．）隶属杨梅科杨梅属，常绿灌木。仅自然分布于我国西部部分省区．为我国特有的窄生态幅植物。本文对矮杨梅的地理分布、生境、群落特征进行了考查。分析了生境对该物种生长、分布的影响；提出了种内变异问题。以期丰富对矮杨梅这一物种的认识。     

沙棘根系模糊聚类及生长分布规律的探讨

本文对黄土残塬沟壑区人工沙棘林单株根系进行了系统研究。结果表明:1.主根龄是影响沙棘单株根系间模糊聚类的决定性因素,幼龄期单株根系间极易聚合,随着主根龄增加,同龄单株根系间差异逐渐加大而较难聚合。2.用灰色Verhoulst模型对单株沙棘根量、根长的变化过程进行描述和预测,当主根龄达到17龄左右时,根系基本停止生长。3.沙棘根量、根长在土体中的垂直分布规律呈双曲函数关系,各实测值与计算值拟合非常贴切。4.沙棘根系密集层随主根龄的增加而加深,最终稳定在0-50cm左右,粗壮根系多集中在该层。文中还建立了沙棘根量与叶量的线性回归方程。     

杨树超短轮伐期经营的生产力及材性的研究

以美洲黑杨２个无性系为供试材料，研究杨树超短轮伐期经营中地上部分生物量生产、分配模式、Ｎ、Ｐ、Ｋ的输出量及材性。结果表明，在３种密度和３种轮伐期的组合中，２个无性系均以造林密度为１００００株·ｈａ－１、轮伐期为３年的林分生物生产力最高，Ｉ－６９杨为１０．５２ｔ·ｈａ－１·ａ－１，ＮＬ－８０３５１杨约为１２．００ｔ·ｈａ－１·ａ－１；在生物量的分配比率和作为造纸材的经济生物量上也以这种组合模式最为合理，经济生物量最大，Ｉ－６９杨为７．１４ｔ·ｈａ－１·ａ－１，ＮＬ－８０３５１杨为８·４７ｔ·ｈａ－１·ａ－１。养分输出量的多少与林分的生物量生产和分配比率密切相关。轮伐期为３年，密度为１００００株·ｈａ－１的林分Ｎ、Ｐ、Ｋ的输出量最高，Ｉ－６９杨为３３．９７ｋｇ·ｈａ－１·ａ－１，ＮＬ－８０３５１杨为３８．５０ｋｇ·ｈａ－１·ａ－１，但ＮＬ－８０３５１杨每生产１吨经济生物量所输出的Ｎ、Ｐ、Ｋ总量略低于Ｉ－６９杨。杨树超短轮伐期经营中生产出的木材都可用作中、低档的造纸原料，其中Ｉ－６９杨的制浆性能优于ＮＬ－８０３５１杨。     

韩国原麝分布区50年间的变迁

在南朝鲜于1999年的2月至12月间,根据有关文献,调查问卷和对原麝的种类,粪便,及其在有雪和无雪的季节里的野外踪迹的调查,作者概述了50年中原麝的数量和分布区的变化。结果表明:从50年代至1999间,原麝(Moschus moschiferus parvipes)的分布区呈明显缩减之势。由于在原麝分布区中大规模地进行公路及林道的建设,导致了其生境片断化和丢失。而且牟取利润的非法猎捕也是造成原麝的种群数量和分布区缩减的主要原因,在高海拔地区的林道也常被盗猎者所利用。为保护韩国原麝资源,急待严格禁止非法猎捕行为。原麝生活习性方面的研究,为合理的保护和管理原麝提供了重要的基础信息。图1参9。     

神农架地区珍衡植物沿河岸带的分布格局

Due to the importance of riparian zone in maintaining and protecting regional biodiversity, increasingly more ecologists paid their attentions to riparian zone and had been aware of the important effects of riparian zone in basic study and practical management. In this study, 42 sampling belts (10 m×100m) parallel to the bank of Xiangxi River at different elevations in Shennongjia Area were selected to investigate the riparian vegetation and rare plants. 14 species of rare plants were found distributing in riparian zone, accounting for 42.4% of the total rare plant species in Shennongjia Area. The main distribution range of the 14 rare plant species was the evergreen and deciduous mixed broadleaved forest at elevation of 1200–1800 m, where, species diversity of plant community was the maximum at the moderate elevation. The analysis of TWINSPAN divided the 14 rare species into 3 groups against the elevation, namely low elevation species group, moderate elevation species group, and high elevation species group. The analysis of DCA ordination showed similar results to that of TWINSPAN. In the paper, the authors discussed the reasons forming the distribution pattern of rare plant species, and pointed out that the important function of riparian zone on rare plant species protection. Foundation item: This project was supported by National Natural Science Foundation of China (NSFC39970123), and Changbai Mountain Open Research Station, Chinese Acadamy of Science. Biography: JIANG Ming-xi (1965-), male, associate professor in Wuhan Institute of Botany, Chinese Academy of Sciences, Wuhan 430074, P. R. China Responsible editor: Chai Ruihai