陕西老县城自然保护区的鸟类多样性及G-F指数分析

2003年7月和2004年5月,利用样线法对陕西老县城自然保护区进行了鸟类多样性调查,结合历史资料,老县城自然保护区共有鸟类13目36科107属190种,其中国家重点保护鸟类16种,我国特有鸟类12种。按季节型区分,其中留鸟116种,夏候鸟56种,冬候鸟、旅鸟和迷鸟共计18种,从分布型区分,东洋种、古北种和广布种分别为70种、87种和33种。多样性指数分析显示,阔叶林生境中鸟类资源最为丰富,其次为针阔混交林。老县城自然保护区鸟类的优势种为红嘴蓝鹊(Urocissa erythrorhyncha)、星鸦(Nucifraga caryocatactes),此外,山雀类(Parusspp.)、柳莺类(Phylloscopusspp.)以及环颈雉(Phasianuscolchicus)也有较大的种群。同时,将老县城自然保护区的鸟类多样性与其周边的佛坪、长青、太白等自然保护区进行了G-F指数对比分析。发现佛坪自然保护区的鸟类多样性无论是F指数、G指数还是G-F指数均为最高,佛坪在鸟纲(AVES)科属水平上拥有相对较高的鸟类多样性。用基于科属水平的G-F指数与基于物种水平的Shannon-Wiener指数相结合评价某一地区的鸟类多样性,将更为客观。     

秦岭山地天然次生林群落MRT数量分类、CCA排序及多样性垂直格局

采用多元回归树(MRT)对秦岭山地天然次生林群落进行数量分类,采用典范对应分析(CCA)进行排序,分析了秦岭山地天然次生林群落物种多样性沿海拔梯度的变化规律。结果表明:(1) 275个样方共有种子植物195种,隶属61科128属。乔、灌、草3个层次物种多样性变化沿海拔梯度的变化趋势基本一致,呈单峰模型;(2)经交叉验证认为秦岭山地天然次生林群落可分为2类,Ⅰ冬瓜杨(Populus purdomii)+陇东海棠(Malus kansuensis)+蛇莓(Duchesnea indica)群落,Ⅱ锐齿槲栎(Quercus aliena var. acuteserrata)+黄栌(Cotinus coggygria)+茜草(Rubia cordifolia)群落;(3) CCA排序结果揭示了群落生境的分布范围,反映出生态轴的排序意义,较好地反映秦岭山地天然次生林群落与环境因子的关系,其结果表明,海拔、坡向、凋落层厚度和干扰情况4个变量对该地区次生林群落的分布有较大的影响。     

秦岭中西部油松径向生长对气候因子的响应差异研究

在气候变暖背景下,树木径向生长对气候因子的响应会随区域干湿变化而有所差异。秦岭属于气候敏感区和生态脆弱区,南北气候特征差异明显,分析气候变化背景下树木径向生长对气候因子及干旱事件的响应,对准确预测未来气候变化对树木生长的影响至关重要。为探究该地区不同干湿环境下油松对气候因子及干旱事件响应的特点及差异,共采集秦岭中西部南北坡共4个样点的油松树轮样芯,利用树木年轮生态学的方法,分析各地油松年表与气候因子之间的关系,通过计算抵抗力、恢复力、恢复弹力等指标探究树木径向生长对干旱事件的应对能力,结果表明：1)在西部和北坡的3个样点,油松径向生长主要与前一年7—9月、当年5—7月的气温呈显著负相关,与当年5月降水呈显著正相关,在中部南坡油松径向生长主要与当年2—4月、9月气温呈显著正相关,与当年4月降水呈显著负相关;2)生长季气温升高所引发的水分亏缺,是研究区西部和北坡油松径向生长受限制的主要原因,且中部南坡油松生长受气温和干旱因子的制约要明显弱于其它3个样点;3)西部北坡油松对干旱的抵抗能力、恢复能力及恢复弹力均弱于西部南坡及中部北坡油松。在未来对研究区树木的管理与保护工作中,应更加关注西部北坡...     

中国陕西秦岭大孢蜈蚣衣属地衣的研究

对采自陕西秦岭地区的大孢蜈蚣衣属地衣从形态学、解剖学、化学方面进行了研究,共鉴定出本属地衣8种,其中P.lobulifera,P.elegantula为陕西新记录种,P.venusta又被列入中国名录。本文给出了分种检索表及种的简要讨论,并附有作者鉴定的标本。     

陕西凤县春季林麝生境的初步分析

2006年4～5月,在陕西凤县共设置41个20 m×20 m的样方和14个生态因子,并以此为基础数据,分析结果表明,林麝春季喜欢选择在海拔1700～2100 m、灌木盖度、竹子密度、倒木密度、树桩密度、动物干扰程度均较低、坡度≥ 40°、半阴半阳坡、远离人类生产活动、有土质覆盖的生境.其他生态因子郁闭度、隐蔽级、乔木密度、灌木密度均以适中为准.因子分析的结果表明,前7个公共因子的累计贡献率达到76.63%,基本上反映了林麝春季栖息地的特征.在前7个公共因子中,占有较高信息载荷系数的变量依次为灌木盖度、树桩密度、乔木密度、活动基底、隐蔽级、人为干扰、竹子密度.     

Thecamoebians from the small streams of the Boubín area (Šumava Mts,Czech Republic)

From 1999–2005, seventy-eight samples were collected from the small streams in the area of the Boubín Mountain including also the natural preserve “Boubínsky prales” (Boubín primeval forest) (Šumava Mts, Czech Republic). Nineteen species of thecamoebians were identified in the samples; the most abundant species were Centropyxis orbicularis, Pontigulasia compressa, Centropyxis aculeata, Difflugia oblonga and Centropyxis arcula. Species composition of assemblages as well as ecological affinities of the most common taxa are comparable with data from the previously analysed streams in the Šumava Mts. This correlation improves the quality of data for environmental preferences of thecamoebian assemblages contained in the streams and these can be used for interpretation of ancient environments. Though species composition of assemblages changes gradually, two end-member assemblages can be defined. For both assemblages, environmental conditions were defined: Lower-diversity assemblages dominated by centropyxids originated mainly from standing water with low content of organic debris. Relative abundances of C. orbicularis showed negative correlations with abundances of other Centropyxis spp. which may indicate different ecological affinities of this species. Centropyxis orbicularis may tolerate higher levels of fine organic debris in stream sediments. Assemblages with common to abundant occurrences of P. compressa and/or D. oblonga prefer running water. Difflugia oblonga dominated in samples with higher content of fine organic debris. Relation between test size of D. oblonga and flow rate was recorded: large D. oblonga prevailed in standing water while small specimens dominated in fast streams.     

The Mts1 protein and control of tumor metastasis

Reviewed are the results of studies on the structure, function, and regulation of themts1 gene and its protein product Mts1.     

Direct inhibitory and indirect stimulatory effects of RAGE ligand S100 on sRANKL‐induced osteoclastogenesis

Diabetes results in increased fracture risk, and advance glycation endproducts (AGEs) have been implicated in this pathophysiology. S100 proteins are ligands for the receptor of AGEs (RAGE). An intracellular role of the S100 family member S100A4 (Mts1) to suppress mineralization has been described in pre‐osteoblastic MC3T3‐E1 cells. However, S100 proteins could have additional effects on bone. The goal of the current study was to determine effects of increased extracellular S100 on osteoclastogenesis. We first determined the direct effects of S100 on pre‐osteoclast proliferation and osteoclastic differentiation. RANKL‐treated RAW 264.7 cell proliferation and TRAP activity were significantly inhibited by S100, and the number and size of TRAP‐positive multinucleated cells were decreased. We then determined whether S100 could affect osteoclastogenesis by an indirect process by examining effects of conditioned media from S100‐treated MC3T3‐E1 cells on osteoclastogenesis. In contrast to the direct inhibitory effect of S100, the conditioned media promoted RAW 264.7 cell proliferation and TRAP activity, with a trend toward increased TRAP‐positive multinucleated cells. S100 treatment of the MC3T3‐E1 cells for 14 days did not significantly affect alkaline phosphatase, M‐CSF, or OPG gene expression. RANKL was undetectable in both untreated and treated cells. The treatment slightly decreased MC3T3‐E1 cell proliferation. Interestingly, S100 treatment increased expression of RAGE by the MC3T3‐E1 cells. This suggested the possibility that S100 could increase soluble RAGE, which acts as a decoy receptor for S100. This decrease in availability of S100, an inhibitor of pre‐osteoclast proliferation, could contribute to osteoclastogenesis, ultimately resulting in increased bone resorption. J. Cell. Biochem. 107: 917–925, 2009. © 2009 Wiley‐Liss, Inc.     

秦岭中段山脊油松叶功能性状差异及其对海拔梯度的响应

山脊油松林是秦岭山地典型的群落类型之一,其在维持生物多样性及发挥生态服务功能等方面具有重要意义.该研究以山脊油松为对象,采用典型取样法研究了秦岭中段山脊油松10种叶功能性状沿海拔梯度的适应性变化规律.结果表明:(1)山脊油松1～3年生各叶龄叶的叶长(LL)、叶氮含量(LNC)、叶磷含量(LPC)和1年生叶的叶绿素[Ch...     

Recovery of ciliate communities from an oligotrophic mountain stream after a catastrophic wind damage

We studied the recovery of ciliate taxoceonoses in a mountain stream after a catastrophic windstorm that strongly affected mountainous regions of Slovakia in 2004. To this end, we analyzed changes in the community structure of ciliate assemblages from the Zubrovica stream in the Low Tatra Mts during the time frame between 2003 and 2008 by various statistical methods, including diversity and similarity indices, hierarchical clustering, multidimensional scaling, and PCA. The climax ciliate communities were characteristic for oligotrophic running waters, i.e., they were equitable (E_H = 0.75–1.00) and harbored a comparatively low number of species (2–9) with typically low abundances (10–125 ind./ml). However, the community structure changed dramatically after the devastating windstorm. There was a significant increase of species number (10–30) and abundance (260–1480 ind./ml), concomitant with a decrease of the equitability (E_H = 0.43–0.83). These changed quantitative and qualitative community parameters wore off comparatively quickly, i.e., about six months after the catastrophic windstorm, the ciliate taxocoenoses had reached a community structure similar to that before the wind damage. The present observations and those from terrestrial habitats indicate that ciliate communities have a good capability to comparatively quickly reach a climax even after a strong disturbance.