A new role for PGRP-S (Tag7) in immune defense: lymphocyte migration is induced by a chemoattractant complex of Tag7 with Mts1

PGRP-S (Tag7) is an innate immunity protein involved in the antimicrobial defense systems, both in insects and in mammals. We have previously shown that Tag7 specifically interacts with several proteins, including Hsp70 and the calcium binding protein S100A4 (Mts1), providing a number of novel cellular functions. Here we show that Tag7–Mts1 complex causes chemotactic migration of lymphocytes, with NK cells being a preferred target. Cells of either innate immunity (neutrophils and monocytes) or acquired immunity (CD4⁺ and CD8⁺ lymphocytes) can produce this complex, which confirms the close connection between components of the 2 branches of immune response.     

秦岭山地松栎混交林主要木本植物组成及更新特征

采用样方法对秦岭南坡中段松栎混交林主要木本植物组成及天然更新特征进行了研究.结果表明:(1)松栎混交林乔木层物种共计40种,油松、锐齿槲栎和华山松为优势种,重要值分别为35.19％、31.99％和8.12％,漆树、栓皮栎和楝木为亚优势种.(2)更新层木本植物共计87种,其中乔木幼苗34种,占总数的39.08％,灌木物种也有一定优势地位,优势种有锐齿槲栎、悬钩子和菝葜等,高度级较小的更新苗在群落内占有较大比例.(3)优势乔木更新特征不同,锐齿槲栎幼苗和幼树密度显著高于油松和华山松,且锐齿槲栎幼苗密度显著高于其幼树,但油松幼苗与幼树、华山松幼苗与幼树间无明显差异.(4)混交林内锐齿槲栎径级结构呈近似倒“J”形分布,种群稳定;油松和华山松种群均呈近似正态分布,大径级个体群相对稳定,但林下幼树不足.该研究结果提示,松栎混交林下油松和华山松更新不良,这将不利于其长期存留于群落中,虽然锐齿槲栎从幼苗到幼树的发育过程中存在更新障碍,但并未影响其种群整体更新,若无大规模干扰,锐齿槲栎将维持逆“J”型的更新方式并成为松栎混交林群落中的第一优势种.     

秦岭山地典型次生林木本植物幼苗更新特征

采用样方法调查了秦岭山地5种典型次生林--油松林、锐齿栎林、红桦林、云杉林和华山松林幼苗的更新特征.结果表明: 不同次生林木本植物幼苗物种分化明显,除锐齿栎林和华山松林外,其余次生林幼苗物种相似性系数均较低;油松林和锐齿栎林木本植物幼苗数量、物种丰富度指数、Simpson优势度指数及均匀度指数均较高,红桦林均最低;云杉林和华山松林幼苗数量及物种多样性指数基本一致.不同次生林幼苗和幼树所占比例存在明显差异,除红桦林幼树数量的比例较大外,其余林分幼苗的比例较大,为云杉林＞油松林＞锐齿栎林＞华山松林.不同林分幼苗萌生比例差异明显,为华山松林＞云杉林＞红桦林＞锐齿栎林＞油松林.锐齿栎林和油松林乔木幼苗比例最高,分别占木本幼苗总种数的68%和51.4%,群落处于演替中期,持续更新能力较强;云杉林、华山松林乔木幼苗比例分别为40%和15%,处于演替后期,更新能力较差;而红桦林中幼苗很难发育成幼树,持续更新能力欠缺.     

秦岭西段鱼类多样性现状初报

对秦岭西段汉江水系和嘉陵江水系的鱼类和环境调查显示,人类活动对鱼类多样性产生了较大的影响。本文试图对该地区鱼类多样性丧失的现状加以报道并对原因进行分析。以前该地区鱼类共有142种,本次调查的渔获物中只有34种。鱼类物种资源的减少是多种因素造成的：水坝的修建使得鱼类栖息地环境改变从而导致鱼类的种类和种群数量变化,水污染、过度捕捞和非法渔业也在一定程度上破坏了鱼类物种多样性。     

贵州梵净山地衣的初步研究

梵净山国家级自然保护区是联合国“人与生物圈网”的成员之一,位于中国西南贵州省的东北部。报道了梵净山地衣物种119种,其中106种为梵净山新记录,79种为贵州新记录,2种为中国新记录:Dermatocar-ponintestiniforme(K rb.)Hasse.和Thelotrema similansNylander,同时对梵净山地衣进行了初步的地理学分析,从而为该地区地衣生物多样性的研究及地衣资源的保护和利用提供了相关资料。     

秦岭中段松栎混交林群落数量分类与排序

依据陕西省境内秦岭山脉中段设置的34个样地调查资料,从植物物种组成、植物群落与地形因子之间的关系等对该区域松栎混交林群落进行TWINSPAN分类和DCCA排序。结果表明:(1)研究区34个样地共记录维管束植物297种,隶属于77科178属,其中被子植物72科,裸子植物2科,蕨类植物3科;分布较广的植物有:松科、壳斗科、蔷薇科、菊科、禾本科和百合科。(2)TWINSPAN聚类结果将样地群落划分为13个群丛,其中以油松+锐齿槲栎为建群种的群丛最多,占总群丛数量40%,是该区主要的松栎混交林群落类型。(3)样地的DCCA排序结果表明,第一轴明显地反映出群落分布沿海拔、坡位的变化,第二轴主要表现出群落分布沿坡向、坡度的变化趋势;其中海拔、坡度与DCCA一、二轴相关系数分别达到最大值(-0.946 2、-0.795 7),是对该群落分布起决定性作用的因子。(4)研究区主要优势物种的DCCA排序与样地的DCCA排序综合反映出该区松栎混交林群落分布的地形梯度。     

Vegetation changes following sheep grazing in abandoned mountain meadows

Abstract. Sheep grazing was investigated as an alternative to traditional management of meadows in the Krkono?e Mts. Until the second World War these meadows were mown in mid‐summer and grazed by cattle for the rest of the season. Subsequent abandonment of the meadows has resulted in decreasing species richness. Degradation phases of the former communities have been replacing the original species‐rich vegetation. Significant changes were apparent six years after the introduction of sheep grazing. In grazed plots the proportion of dominant herbs (Polygonum bistorta and Hypericum maculatum) decreased and grasses (Deschampsia cespitosa, Festuca rubra, Agrostis capillaris, Anthoxanthum alpinum) increased. The increase in grasses was positively correlated with an increase in several herbs. The proportion of some herbs increased despite being selectively grazed (Adenostyles alliariae, Melandrium rubrum, Veratrum lobelianum). Any losses caused by grazing of mature plants were probably compensated by successful seedling establishment. Cessation of grazing resulted in significant changes in vegetation within three years. The cover of nitrophilous tall herbs and grasses (e.g. Rumex alpestris, Holcus mollis, Deschampsia cespitosa, Geranium sylvaticum) increased in the abandoned plots. In the plots grazed for nine years cover of species‐rich mountain meadow species increased (e.g. fine‐leaved grasses, Campanula bohemica, Potentilla aurea, Viola lutea, Silene vulgaris). The main conservation risk is the expansion of a competitive species with low palatability, Deschampsia cespitosa. This species can be suppressed by a combination of grazing and mowing. In order for grazing to be effective, the number of sheep should be proportional to meadow production. This may be difficult to maintain as production is variable and is impossible to predict at the beginning of a growing season. A large part of the biomass may thus remain intact in some years. Negative effects of grazing may be, at least partly, eliminated by a combination of cutting and grazing.     

秦岭山区中国大鲵生境因子的选择

通过对秦岭山区中国大鲵(Andrias davidianus)栖息地生境因子调查、统计,利用R语言分析了各因子与大鲵生境选择的相关性,得出研究结果:秦岭山区影响大鲵生存的主要因子为栖息地类型(相关系数r=0.98),其次是水温(相关系数r=-0.8)、河岸坡度(r=-0.6)和p H (r=-0.6);浊度(相关系数r=0.5)、电导率(r=0.49)、DO(r=0.4)、人为干扰(r=0.35)和海拔(r=0.31)对大鲵分布影响不大。研究结果为探讨中国大鲵对野生环境的适应性选择提供了参考。     

Constructive Species’ Coexistence Mechanisms of Pine Oak Mixed Forest in Qinling Mountains Based on the Niche Differentiation

Based on the 15 plots of Pinus tabuliformis and Quercus aliena var. accuteserrata mixed forest in Qinling Mountains, we analyzed this community’s characteristics from the aspects of species composition, niche width and diameter class, also, we used the Canonical Correspondence Analysis to explore the effects of environment on plants’ distributions and conductive species’ morphological characteristics, the main results were as follows: (1) Fifteen plots record 139 vascular plants, belonging to 53 families 102 genera, the families which possessing higher richness were Rosaceae, Asteraceae, Liliaceae and Poaceae; (2) The niche widths of Ptabuliformis (Bi=2674) and Q var. accuteserrata (Bi=2679) were all higher than other accompanying plants, and there was little niche overlap value (< 01) between them; (3) Organic matter, total nitrogen, elevation and slope mainly effected plant’s distributions; (4) Four morphological characteristics of constructive species in CCA diagram presented a opposite distribution patterns, while elevation, slope position and available nitrogen were the main induced factors; (5) Community stability of this pine oak mixed forest was relatively higher based on Godron index, and two conductive species’ diameter class were all growing type. In conclusion, high habitat heterogeneity of terrain and soil nutrient brought niche differentiation and promoted species coexistence of pine oak mixed forest in Qinling Mountains.     

佛坪国家自然保护区地面生苔藓植物物种多样性

通过对秦岭南坡佛坪国家自然保护区地面生苔藓植物的调查,采用相似性系数、重要值、多样性指数对其进行物种多样性的研究。结果表明:29个样地内地面生苔藓植物共33科69属189种,包括苔类植物7科8属15种和藓类植物26科61属174种,其中青藓科是最优势的科。落叶阔叶栎(Quercus)林下地面生苔藓植物的物种多样性最高,其次是落叶阔叶桦(Betula)林带、竹林、针叶林和沟谷岩石,杜鹃(Rhododendron)灌丛带的最低。落叶阔叶栎林带和落叶阔叶桦林带的种相似性最高,杜鹃灌丛与其它植被带的种相似性都很低。研究表明秦岭南坡的佛坪国家自然保护区内,低山地区的落叶阔叶栎林带是该地区苔藓植物多样性的分布中心,是物种多样性保护的关键地带;亚高山地区杜鹃灌丛带的苔藓植物物种多样性虽然不高,但种类明显不同于别的地带,所以也应是苔藓植物多样性保护值得注意的地带。