黄土丘陵沟壑区小流域基流特点及其影响因子分析

在对青海湖高寒湿地进行群落调查的基础上,研究了在群落梯度上高寒湿地的生物多样性与生产力的关系,并探讨了在同一区域内环境的整体性对高寒湿地的生物多样性与生产力关系的影响。运用SPSS软件进行曲线拟合,研究了青海湖内陆高寒湿地物种多样性和地上生物量的关系。研究结果表明,(1)无论是在群落尺度上还是在区域尺度上物种多样性指数与地上生物量呈显著的负相关。(2)在研究区内区域因素对物种多样性和生产力的影响较弱,但如果保持区域环境的整体性则可以有效地提高物种多样性和生产力的相关程度。     

The importance of C,N and P as driver for bacterial community structure in German beech dominated forest soils

Among several environmental factors shaping soil microbial communities the impact of soil nutrients is of special interest. While continuous application mainly of N and P dramatically shifts community composition during fertilization, it remains unclear whether this effect is consistent in generic, unfertilized beech forest ecosystems of Germany, where differences in nutrient contents are mostly a result of the parental material and climatic conditions. We postulate that in such ecosystems nutrient effects are less pronounced due to the possibility of the soil microbiome to adapt to the corresponding conditions over decades and the vegetation acts as the major driver. To test this hypothesis, we investigated the bacterial community composition in five different German beech dominated forest soils, representing a natural gradient of total‐ and easily available mineral‐P. A community fingerprinting approach was performed using terminal‐Restriction Fragment Length Polymorphism analysis of the 16S rRNA gene, while abundance of bacteria was measured applying quantitative real‐time PCR. Bacterial communities at the five forest sites were distinctly separated, with strongest differences between the end‐members of the P‐gradient. However the majority of identified microbial groups (43%) were present at all sites, forming a core microbiome independent from the differences in soil chemical properties. Especially in the P‐deficient soil the abundance of unique bacterial groups was highly increased, indicating a special adaption of the community to P limitation at this site. In this regard Correspondence Analysis elucidated that exclusively soil pH significantly affected community composition at the investigated sites. In contrast soil C, N and P contents did mainly affect the overall abundance of bacteria.     

华北土石山区植物群落多样性特征分析

根据12个样地的调查资料，分析了八达岭地区天然林植物群落物种多样性的特征，群落内部各层次物种多样性指数的顺序依次为：草本层＞灌木层＞乔木层，但在糠椴（Tilia mandshurica）林和核桃楸（Juglans mandshurica）林中由于特殊的生境表现为：灌木层＞草本层＞乔木层。白梨（Pyrus bretschneideri）山丁子（Malus baccata）林和核桃楸林群落中Sorenson指数最小，共有种最少，群落间多样性最大。     

安徽琅琊山落叶阔叶林结构及其土壤特性

 以琅琊山落叶阔叶林为研究对象,对样地林分进行每木检尺,并对林下更新状况及土壤特性进行调查分析。结果表明:4块样地共出现树种8种(胸径≥3.0 cm),分属7科9属,以槭树科和榆树科为主;群落垂直结构简单,灌木层和草本不甚明显。乔木层中的五角枫、榉树、化香3个树种居绝对优势地位,琅琊山落叶阔叶林的树种多样性较低。不同林分土壤理化特性表现为:呈中性至微酸性反应,EC值、有机质、速效P及速效K含量都较高,N含量中等,综合养分条件较好;土壤pH(H2O)值、速效N和全N是影响各调查林分林木生长及林下更新的主要因子。研究结果可为琅琊山森林的自然更新和可持续经营提供科学依据。     

陕北黄土区植被特征对坡面微地形的响应

为掌握陕北黄土区不同植被特征对坡面微地形的响应,以陕西省吴起县合沟流域半阴、半阳2个坡向的原状坡及其5种微地形为研究对象,分析对比不同坡向各类微地形的物种组成、草本生物量、植被盖度及植物多样性特征.结果表明:1)各类微地形植物群落的物种组成、植被盖度、草本生物量及植物多样性指数多优于原状坡,其中切沟和塌陷的植被状况最优,其次为浅沟和缓台,陡坎最差;2)各类微地形植物群落的Simpson指数与Shannon-Wiener指数变化趋势一致,均为切沟＞塌陷＞缓台＞浅沟＞陡坎＞原状坡,其中切沟和塌陷的植物群落所处的自然演替阶段高于其他微地形;3)经过15年自然恢复,半阳坡形成以星毛委陵菜、赖草等多年生草本植物为优势种的植物群落,半阴坡形成以铁杆蒿、茭蒿等地带性多年生草本植物为优势种的植物群落,半阴坡各类微地形植物群落的物种组成状况、草本生物量、植被盖度以及植物多样性特征指数均优于半阳坡.掌握不同微地形植被配置的差异,有助于提高陕北黄土区植被恢复措施的有效性和持续性.     

梭梭水力提升与浅根系植物优势度、丰富度和多度的关系

[目的]探究梭梭水力提升与浅根系植物优势度、丰富度和多度之间的关系,以了解干旱区荒漠林内深、浅根系植物的种间关系,对干旱荒漠区植物的利用与保护提供理论依据。[方法]利用群落调查、同位素示踪和对比分析等方法对新疆艾比湖荒漠中梭梭是否拥有水力提升、以及其与植物优势度、多样性之间的关系进行了探索。[结果](1)梭梭拥有水力提升现象;(2)相对梭梭树冠外的浅根系草本和灌木,其树冠下浅根系草本和灌木的生长优势度指数较高,长势更好;(3)一年生长过程中,梭梭树冠下灌木和草本群落的物种多度和丰富度均显著高于树冠外(p0.05)。[结论]干旱区荒漠群落的建群种梭梭拥有水力提升过程,该过程能够改善浅层土壤水分条件,从而使得其伴生的浅根系草本和灌木的长势更好,影响着干旱区荒漠群落的物种多样性维持过程。     

阿克苏河中游荒漠河岸林物种多样性与群落稳定性

[目的]探究阿克苏河中游荒漠河岸林群落的物种多样性、稳定性及其之间的关系,在物种水平上对当前群落植物组成的复杂性及部分环境因子的关系进行探讨,为荒漠河岸生态系统的恢复提供理论依据。[方法]在样方调查的基础上,运用格局分析法,物种多样性指数与均匀度指数,聚类分析以及M.Godron稳定性测度对植物群落进行综合评估。[结果]阿克苏河中游荒漠河岸林主要的植物种群均呈现聚集分布的格局,群落结构简单,具有单寡种优势群落的特征。不同地段的植物群落物种分布较为均匀,但丰富度与多样性的高低略有起伏;荒漠河岸林植物群落根据环境因子的聚类结果可分为6个群丛,其中有3个群丛的物种多样性较低。物种组成与土壤水分的关联较为密切;当前植物群落尚未达到稳定阶段,物种多样性与群落稳定性者之间并无任何直接联系。[结论]单一以河水漫灌的方式促进该地区植物多样性的恢复具有一定的困难,考虑以胡杨、柽柳为主要格局,种植深根系的乔灌木以营造局部地区小气候,间接优化生境的方式对荒漠河岸林的植被恢复更为有利。     

华北土石山区天然森林植被演替中群落结构和物种多样性变化的研究

基于华北土石山区潮关西沟流域天然森林植被调查的基础上．对森林植被群落演替中群落树种组成、胸径结构和生物多样性变化进行了研究。结果表明，随着演替的进行．群落的乔灌木树种数先升高后降低，趋于稳定。而乔木密度呈增加趋势，而灌木密度和乔木树种的最大株数比例的胸径范围呈不断降低趋势。群落的乔木、灌木和乔灌木的物种多样性、丰富度随着演替的进行先升高后降低。除了栎树林乔木和平榛灌丛的乔灌木的均匀度较低外，乔木、灌木和乔灌木其他群落的均匀度变化不明显。     

Polypore diversity in the herb-rich woodland key habitats of Koli National Park in eastern Finland

Species diversity of polypores (Basidiomycetes) was compared between woodland key habitats (WKHs) and old-growth forest controls in boreal forests in eastern Finland. WKHs, which were set aside for their rich vascular plant flora, turned out not to be hot spots for the species richness of polypores, nor did their species composition represent the overall species richness of the area. Differences in the total volume of CWD, tree species composition and several CWD qualities were reflected as differences in the species assemblages between the groups. The results indicated that only a fraction of the overall polypore diversity was represented in the small-size WKHs (<0.5 ha), and the protection of red-listed and indicator polypores in WKHs was random. However, rare old-growth forest indicators were found even in small-size WKHs, if the CWD quality was appropriate for them. Nevertheless, our study does not answer the question whether the occurrences of rare and red-listed species will survive in small-size WKHs surrounded by altered environments such as clear-cuts, because our study sites were located in undisturbed areas. The results stress the importance to protect typical old-growth forest patches with high CWD volume and quality in boreal forests.     

北川河流域退耕还林还草地主要植物群落物种多样性研究

对大通县北川河流域内不同植物群落全面考察的基础上,根据立地条件、植被及土地利用方式等因素,选取代表性地段,设置了24个标准地,应用丰富度指数、Gleason指数、Simpon指数、Shannon-Wienner指数和均匀度指数来综合分析物种丰富度、生态优势度、群落物种多样性和均匀度。结果表明:在不同的退耕时间序列上,随着时间的推移,群落逐渐趋于稳定,群落物种多样性和丰富度呈“小-大-小”的变化过程,而均匀度和优势度指数呈“大-小-大”的变化过程;对不同起源地的群落多样性,天然林>退耕地>耕地,且退耕多年地段的群落物种多样性接近于天然林。     

宝天曼自然保护区栓皮栎林人工恢复与天然恢复效果比较

为比较宝天曼自然保护区内栓皮栎林人工恢复天然恢复的差异,采用样地调查法对相同恢复年限的栓皮栎人工林与天然次生林的物种组成、重要值、多样性指数和土壤性质等群落特征指标进行了比较研究。结果表明:(1)栓皮栎人工林群落具有维管束植物12科18属24种,次生林群落具有维管束植物27科40属48种,两个群落相似性较低(0.36);(2)栓皮栎次生林乔木层和灌木层物种的重要值比人工林低,乔木层和灌木层的物种数较人工林多;(3)栓皮栎人工林与次生林群落的乔木层、灌木层和草本层的Maglef指数、Shannon-Wiener指数、Simpson和Pielou均匀度指数相比均较低,人工林的4个多样性指数大小依次为灌木层、草本层、乔木层,天然次生林指数大小表现依次为灌木层、乔木层、草本层;(4)栓皮栎次生林的土壤全氮、全磷、有机质含量比人工林均较高。研究表明在宝天曼自然保护区内,相同恢复的年限,栓皮栎天然次生林无论物种组成、多样性指数、群落结构和土壤理化性质均优于栓皮栎人工林,天然恢复比人工造林恢复效果好。     

辽东山地老秃顶子冰缘地貌植物群落多样性

[目的]研究老秃顶子冰缘地貌植物群落的多样性特征,为其上植被的保护提供科学依据。[方法]基于48个样地的群落调查数据,采用物种丰富度指数和α多样性指数,对石海、石河、石流坡3种冰缘地貌植物群落的多样性进行定量研究,并对其影响因素进行分析。[结果](1)植被划分为22个群系,6种植被类型,其中石河地貌上植被类型以落叶阔叶林、针阔混交林为主;石海地貌上以灌丛、灌草丛为主;石流坡地貌上以针阔混交林为主,22个群系对应分布于3种地貌,有些群系具有专有性,有些具有共有性。(2)3种冰缘地貌群落总体综合多样性指数大小依次为:石河石流坡石海,乔木层、灌木层综合多样性指数变化均次为:石河石流坡石海;草本层依次为石海石流坡石河。(3)不同植被类型、不同植物群系的物种多样性因所处的生境特征不同而出现差异。(4)地形因子中的海拔对植物群落物种多样性指数影响最大,且灌木层的物种多样性对海拔敏感程度最小。[结论]研究区植物群落的多样性特征较好,海拔是影响多样性指数的主导因子。     

河北省坝上地区森林节肢动物群落生物多样性研究

通过对位于河北省北部的塞罕坝国家森林公园的森林节肢动物群落进行调查,发现随林分类型不同节肢动物群落存在差异。混交林中节肢动物的物种数要多于纯林,且物种的个体数也较纯林分布的均匀;纯林则经常会存在一个优势种,其数量有时可达到总个体数的70%之多。分别运用物种多样性、物种均匀度、物种优势度等指数的计算公式分析各样地所的数据,发现混交林的物种多样性指数和物种均匀度指数要高于纯林,而对物种优势度进行方差分析则发现混交林和纯林优势度指数并没有显著差异。     

人为干扰对高黎贡山社区森林树种多样性的影响

研究人为干扰活动对高黎贡山社区森林树种多样性的影响结果表明 ,人为干扰对该社区森林有明显的负面影响 ,减少了群落树种多样性和破坏森林群落结构 ,降低森林资源量。当地居民对森林树种选择性的砍伐 ,使群落优势种组成发生变化 ,导致某些树种种群减小 ,物种生存受到极大威胁。并提出减少人为干扰的策略。     

Nutritional characteristics of mineral elements in tree species of tropical rain forest,West Sumatra,Indonesia

The nutritional characteristics of mineral elements in tree species were studied in a 1 ha permanent observation plot at Mt. Gadut area near Padang, West Sumatra, Indonesia. The elemental composition of the 42 leaf and the 457 bark samples from the 1 ha plot was analyzed. Most of the elements, such as S, K, AI, CI, Si, B, and Sr, showed a significant correlation between leaf and bark, suggesting that bark can also be used to study the nutritional characteristics of trees instead of leaves as the first approximation. The concentrations of elements in 457 bark samples showed a wide range, indicating the considerable diversity of nutritional characteristics of mineral elements among these tree species. The concentration ranges expressed in mg kg-¹ were Mn (0.1–3,800), Sr (0.1–1,070), Si (2–1,700), Fe (0.6–4,100), Al (10–46,000), Mg (10–7,200), Zn (0.4–290), K (60–22,000), Cu (0.8–150), P (19–2,540), CI (110–9,200), S (170–13,600), Ca (2,300–100,000), B (4–70), and N a (130–700). Accumulator species were defined as trees with concentrations higher than logarithmic mean + 2std., whereas excluder species were defined as trees with concentrations lower than logarithmic mean — 2std. Among the 113 tree species identified, the accumulators were A. maingayi, M. glaberrimus, M. laurinum, P. axillaris, S. javensis, and M. sericea for S, A. frutescens, A. maingayi, M. laurinum, M. corymbosus, and E. acuminata for Al, F. ribes for Ca, B. pendula and U. maerophyllum for Cl, M. affinis and M. sereea for Si, M. affinis, L. elegans, G. maerophyllum, C. seorteehinii, and E. decipiens for Na, G. macrophyllum, E. opaea, E. latifolia, and C. arborea for B, E. opaea for Cu, F. lepicarpa for Fe, G. maerophyllum and E. opaea for P, A. malaccensis for Zn. The excluders were L. conoearpus for S, V. umbonata, L. conocarpus, S. elongata, G. forbesii, and M. serieea for Al, V. umbonata, L. conocarpus, P. grandis, P. eaeruleseens, G. forbeii, and H. arthoearpoid for Ca, V. perakensis, L. conocarpus, C. seorteehinii, and P. grandis for Mg, V. perakensis, B. tokbrai, C. zollingeriana, G. forbesii, and E. fastigiata for Na, P. exeelsa for Cu, A. porteri for Fe, P. alnifolia for Mn, L. conocarpus and G. forbesii for Sr. Specific Al accumulators were observed. M. corymbosus and U. macrophyllum accumulated Al at very high concentrations, 40 and 20 g kg-¹, respectively. Moreover, Al was accumulated not only in the mature leaves but also in the new leaves. A significant correlation between Al and P concentrations in the 457 bark samples was also observed. These observations suggest that Al exerts a beneficial effect on plant growth for certain tree species in the plot by stimulating P absorption.     

榆林风沙草滩区物种多样性研究

通过对榆林风沙草滩区的主要物种进行考察,根据植被、立地条件及土壤水分等因素,选取5个典型样地,应用物种丰富度指数（R1）、Shannon--Weiner多样性指数（H）、Simpson多样性指数（D）和Pielou均匀度指数（E,）综合分析了主要物种的丰富度、多样性和均匀度,并对其重要值和土壤水分与物种多样性的关系进行了研究。结果表明,榆林风沙草滩区主要物种的多样性排列顺序为：紫穗槐群落〉柠条群落〉踏郎群落〉沙柳群落〉沙蒿群落;均匀度排列顺序为：沙柳群落〉紫穗槐群落〉柠条群落〉踏郎群落〉沙蒿群落;土壤含水量排列顺序为：紫穗槐群落〉沙蒿群落〉沙柳群落〉柠条群落〉踏郎群落。     

Effects of nonnative fish and habitat characteristics on lentic herpetofauna in Yosemite National Park, USA

Nonnative fishes have been introduced into naturally fishless mountain lakes worldwide, often with negative consequences for native fauna. In this study, I used data collected during a census of native herpetofauna, nonnative trout, and habitat characteristics at all lentic water bodies in Yosemite National Park (n=2655) to quantify the effect of trout introductions and habitat on the distribution of four amphibian species and two reptile species. Impacts of trout on amphibians and reptiles were characterized using generalized additive models that included as predictor variables fish presence/absence, amphibian presence/absence (only in models for the two reptile species), elevation, water depth, littoral zone and shoreline substrate composition, relative survey date, and location. All species showed significant associations with habitat characteristics, and elevation and water depth appeared particularly important in influencing distributions. In addition, distributions of the mountain yellow-legged frog (Rana muscosa) and Pacific treefrog (Hyla regilla) were strongly negatively associated with the presence of nonnative trout while those of the Yosemite toad (Bufo canorus) and Sierra newt (Taricha torosa sierrae) were unrelated to trout presence. The distribution of the mountain garter snake (Thamnophis elegans elegans) was strongly negatively associated with the presence of nonnative trout and positively associated with the presence of native amphibians. Regression results for the Sierra garter snake (Thamnophis couchi couchi) were similar except that the direct effect of nonnative trout was considerably weaker. Together, these results indicate that trout introductions have resulted in considerable alteration of Yosemite's herpetofauna. Long-term studies will be necessary to determine whether removal of nonnative trout populations, where possible, would allow these impacts to be partially reversed.     

乌兰布和沙漠绿洲东缘植被群落结构及物种多样性研究

根据乌兰布和沙漠东北部绿洲东缘7个样区25个样地的样方调查数据,对该区植物群落结构及物种多样性进行分析。结果表明:研究区自然植被共有52种,分属17科45属,以菊科为优势种,禾本科、豆科和藜科为亚优势种,其他13科为伴生种;群落结构类型以灌木群落为主,草本群落次之;根据群落物种多样性变化规律,可以将研究区划分为南北两部分,南部多样性指数变化幅度较小且保持较高水平,北部多样性指数变化幅度较大且相对较低;沙漠地区通过绿洲防护林建设,能有效改善绿洲外围植物生长环境,增加植物群落物种多样性,控制沙漠扩张。     

五台山森林群落中物种多样性对旅游干扰的生态响应

在对五台山森林植被进行分类的基础上,利用丰富度指数、均匀度指数和多样性指数,研究了不同森林群落中物种多样性对旅游干扰的生态响应。结果表明:(1)各项指数与群落类型有关,群落物种数量越多,其丰富度较大;群落结构越复杂,层次越分明,其多样性指数越大。同时,各项指数与群落发展的限制因素有关,干扰区群落多样性主要受旅游的影响,非干扰区群落多样性主要受海拔等自然条件的影响。(2)干扰区森林群落随着旅游影响的增大,除Simpson指数外,其它指数都呈现下降的趋势。非干扰区森林群落随着海拔高度的增加,除Simpson指数和Alatalo指数外,其它指数都呈下降的趋势。     

西天山野果林小檗群落特征及物种多样性

[目的]调查西天山野果林小檗群落基本生态特征,为其资源保护、可持续利用和种群修复提供科学理论依据。[方法]选择典型小檗群落随机布置临时样地对其物种组成、垂直结构、种群径级结构及物种多样性进行调查,揭示小檗群落物种组成、群落结构、种群更新等方面的特点。[结果]西天山野果林小檗群落调查样地中共有种子植物19科,47属,50种,其中92.00%为双子叶植物,群落在垂直结构上可分为3层:乔木层、灌木层和草本层;灌木层小檗的重要值为196.25%,群落内各层物种多样性复杂程度总体表现为:草本层乔木层灌木层。该群落中小檗成年个体明显多于幼苗、幼树和老年个体。[结论]西天山野果林小檗群落植物区系温带属性较明显,小檗为群落的单优种与建群种。小檗种群的维持依赖于中龄个体,幼树较少,种群年龄结构呈纺锤状,属衰退型种群。