黄土残塬沟壑区流域次生植被物种分布的地形响应

研究流域次生植被物种对地形因子的响应规律,识别影响次生植被物种分布的主要地形因子,是流域近自然植被生态恢复和重建的基础。采用ArcGIS空间分析模块和地形分析模块TauDEM,并与统计软件SPLUS2000中的GRASP工具相结合,建立了位于黄土高原残垣沟壑区山西省吉县蔡家川流域次生植被各个物种分布基于地形因子的广义相加模型(GAM)。模型中的地形因子包括:海拔、坡向、坡度、平面曲率、坡位指数(SPI)、地形湿度指数(TWI)、单宽汇水面积(SCA)等。受试者操作特征曲线(ROC)测试中AUC值表明:大部分测试物种(约62%)拟合模型效果较好,且模型较为稳定。总体来看,研究流域次生植被物种分布体现了水分限制的空间分异特征:阴坡各物种分布概率较大,且随海拔升高而减小。影响研究流域次生植被物种空间分布的潜在重要因子为海拔和坡向,而单宽汇水面积(SCA)和地形湿度指数(TWI)虽然是多个物种响应模型的预测因子,但受高一级尺度海拔的影响,SCA与TWI对物种分布的影响作用较小;坡度影响作用最小。据此,在流域植被恢复和防护林建设目标区选择及立地条件划分时应首先以海拔和坡向为依据,单宽汇水面积(SCA)和地形湿度指数(TWI)则可以作为次一级立地分类依据,而坡度则仅能作为最后一级的分类依据。

基于植被物种丰富度的山西省高速公路植被物种多样性调查研究

以山西省高速公路植被物种多样性为研究对象,选取山西省内6条运营高速公路共10处路堑边坡开展实地调查,探讨在不同地理区位、绿化用地地质类型、绿化生态修复施工技术、运营时间等因素下,山西省植被物种丰富度差异。通过调查分析可知:高速公路植被物种多样性受地理区位、绿化用地地质类型、绿化生态修复施工技术等3个要素的影响较大,受运营时间影响较小。其中,晋南地区高速公路植被物种多样性最佳、晋中地区次之、晋北地区最弱;黄土边坡植被物种多样性优于其他不良地质边坡;应用生态修复技术后的边坡植被物种多样性明显优于传统穴栽植被种植技术。

环境因子对桂西南蚬木林下植被物种多样性变异的解释

探索林下植被分布格局及其影响因素,对于天然林保护和森林生物多样性维持机制研究具有重要意义。本文以桂西南喀斯特地区不同蚬木(Excentrodendron tonkinense)天然成熟林为研究对象,采用植物群落样方调查、单因素方差分析、Pearson相关分析和冗余分析(RDA)等方法,研究了8个县市蚬木天然成熟林林下植被物种多样性的变异及其对土壤、地形和光照等环境因子的响应。结果表明,林下植被中灌木层优势种主要有越南槐(Sophora tonkinensis)、鹅掌柴(Schefflera heptaphylla)、毛果翼核果(Ventilago calyculata),以及乔木层幼苗如蚬木、广西澄广花(Orophea anceps)、岩樟(Cinnamomum saxatile)、金丝李(Garcinia paucinervis)等,主要来自豆科、五加科、鼠李科、椴树科、番荔枝科、樟科、藤黄科和大戟科等;草本层优势种主要有肾蕨(Nephrolepis cordifolia)、石山棕(Guihaia argyrata)、崖姜(Pseudodrynaria coronans)、柔枝莠竹(Microstegium vimineum)、水蔗草(Apluda mutica)、沿阶草(Ophiopogon bodinieri)等,主要来自肾蕨科、棕榈科、槲蕨科、禾本科、百合科、铁角蕨科和鳞毛蕨科等。土壤pH值、土壤含水量(SWC)、土壤全钾(TK)、土壤全磷(TP)和坡度(SLO)是林下植被物种多样性的主要影响因素,它们分别解释了林下植被物种多样性32.3%、16.1%、9.7%、8.6%和8.6%的变异。灌木丰富度、灌木多样性指数与TK、SWC、土壤pH值和TP显著负相关,而草本丰富度、草本多样性指数则与TK显著正相关;灌木密度、灌木盖度与土壤pH值显著正相关,草本密度与SWC和TK显著正相关,草本盖度与TP、TK显著正相关,与坡度显著负相关。土壤和地形因素是影响林下植被物种多样性变异的最主要因素,而林分冠层结构的影响较小,土壤各因素对林下植被物种多样性的影响高于地形因素。

高校校园植被功能分区的多样性变化与均质化——以内江师范学院高桥校区为例

校园,特别是高校作为城市植被资源的重要组成部分,以西南地区高校为研究对象,分析了目标校园各功能分区植物群落的种类、结构特征、多样性变化规律以及均质化现象。结果显示:(1)校园中乔木和草本植物种类较为丰富,公共休闲区域和教学区在层次的植被种类均较高,运动区和入口区的物种数相对较少;(2)校园的样地植被面积与Menhinick、Pielou指数具有极显著与显著负相关性,除Margalef指数与Pielou指数之间无相关性,其他指数间均呈现显著或极显著相关性,在校园中,物种优势度对群落多样性指数贡献最大,其贡献度依次为优势度指数D>优势度指数D_(B-P)>丰富度指数D_(Margalef)>丰富度指数D_(mn)>均匀度指数E;(3)校园乔木层的生态稳定性高于灌木层和草本层,各区域间生态稳定性相似,休闲区、建筑区、教学区和宿舍区各层次植被相似较高。在各区域相同优势植被中,存在大量引种的观花木本和地被植物,导致了校园景观的雷同性和植被均质化现象。

鄱阳湖湿地土壤种子库特征及其与地表植被的关系

通过幼苗萌发法研究了鄱阳湖湿地自然保护区内蚌湖、大湖池、中湖池、沙湖、象湖等5个湖泊的不同水位湖滨带土壤的种子库特征,并比较了土壤种子库与秋季地表植被在物种组成上的差异.研究结果表明,种子库中共计萌发了52个物种,其中沙湖最多有35种,而蚌湖最少只有21种.种子库中萌发出的幼苗以牛毛毡(Heleocharis yokoscensis)、沼生水马齿(Callitriche palustris)、刚毛荸荠(Eleocharis valleculosa)、看麦娘(Alopecurus aequalis)、苦草(Vallisneria natans)、陌上菜(Lindernia procumbens)等数量最多.地表植被中则出现了68个物种,以红穗薹草(Carex gotoi)、灰化薹草(Carex cinerascens)、水蓼(Polygonum hydropiper)、蚕茧蓼(Polygonum japonicum)、荻(Triarrhena sacchariflora)等物种的盖度最高.5个湖泊的土壤种子库与地表植被在物种组成上的相似系数都比较低,平均相似系数为25.22%,这表明在秋季退水后,鄱阳湖湖滨湿地植被的恢复与建立主要依赖于根茎等无性繁殖体,土壤种子库的贡献较少.

林分密度对华北落叶松天然次生林林下植被和土壤呼吸的影响

为实现“碳中和”背景下的森林高质量经营,探索林分密度调控对森林生态系统土壤呼吸和林下植被物种多样性的影响具有非常重要的意义。以山西五台山林区华北落叶松(Larix principis-rupprechtii)天然次生林为研究对象,设置不同林分密度样地,调查林下植被物种多样性并测定土壤呼吸速率,分析林分密度对林下植被物种多样性和土壤呼吸速率的影响以及物种多样性和土壤呼吸速率的耦合关系。结果表明,喜光植物的重要值随林分密度增加而逐渐降低,在高密度林分中变成偶见种或消失,耐荫植物的重要值随林分密度增加而升高,在高密度林分中成为代表性种。林下植被物种多样性和土壤呼吸速率均随林分密度增加均呈先上升后下降的趋势;香农-威纳指数、辛普森指数、基于香农-威纳指数的均匀度指数、基于辛普森指数的均匀度指数和物种丰富度指数均在中密度下达到峰值,土壤呼吸速率也在中密度下达到峰值;植被种类、林下植被物种多样性指数与土壤呼吸速率的相关性极强,其中物种丰富度指数对土壤呼吸速率的影响最显著。

闽北丘陵地区杉木林林下植被多样性研究

杉木是我国南方主要的速生用材树种之一,在林业生产中占有重要地位。该文通过对杉木纯林、5杉木5木荷、5杉木5马尾松3种不同杉木造林林分林下植被进行调查研究,结果表明:杉木、木荷混交林,杉木、马尾松混交林和杉木纯林林下植被物种数分别为32种、27种、16种,其中杉木、木荷混交林最多,杉木纯林最少;3种林分中,杉木、木荷混交林H>杉木、马尾松混交林H>杉木纯林H,表明针阔混交林物种多样性比针叶混交林和针叶纯林丰富。

Study on Species Diversity of Alpine Vegetation with Different Altitudes in Daban Mountain

[Objective] The aim of this study is to investigate species diversity of alpine vegetation in different altitudes of Daban mountain. [Method] Plant communities were surveyed in three different altitudes （3 025 m,3 405 m,3 813 m） of Daban mountain,the eastern Qilian,and the richness or diversity index of vegetation in three different altitudes was comparatively analyzed. [Result] The species richness decreased with the gradual increase of altitude,and species diversity of plant communities was relatively lower in medium altitude. Furthermore,community similarity also decreased with the increase of altitude,and β diversity of communities had a significant change. [Conclusion] Environmental factor change caused by different altitudes and human disturbance are important reasons for the change of species distribution pattern in different altitudes.

Effect of Site Factor on Plant Community Characteristic in Closed Watershed in Loess Hilly and Gully Region

[Objective] The aim was to study the effect of site factor on plant community characteristic in closed watershed in loess hilly and gully region.[Method] Based on the investigation of vegetation in the closed watershed of Wuqi County in Shaanxi Province,the difference of plant community characteristic and species diversity under various site types was researched in our paper.[Result] In the investigation area,xerophytic herb was the main community,with sole species composition and simple community structure.Zonal vegetations were Artemisia sacrorum and Artemisia giraldii community;for plant diversity,the order of diversity index was ridge topgully bottomridge slopegully slope in various landform positions and semi-shady slopeshady slopesemi-sunny slopesunny slope in various slope aspects;with the increase of gradient,the diversity index of sunny slope changed with ＂S＂ type,and it reached maximum value at 37°.[Conclusion] Our study could provide theoretical foundation for vegetative restoration in loess hilly and gully region.

林窗理论在山地型城市森林建设中的应用前景

从森林循环演替、森林特殊的生境、边缘效应、森林植被物种多样性及森林景观格局多样性等方面论述了林窗干扰作用,并讨论了林窗理论在山地型城市森林建设中森林动态管理、森林景观格局优化和林相改造等方面的应用前景。

Structure changes and succession dynamic of the natural secondary forest after severe fire interference

The structure and dynamic succession law of natural secondary forest after severe fire interference in recent 20 years were studied by adopting the method of deducing time series from the spatial sequence of vegetation in Heihe region, Heilongjiang, China. Two typical and widely distributed forest types in the study area, namely forest type A and forest type B, were selected as study subjects. Forest type A is pure broadleaf forest or broadleaf mixed forest mainly composing of superior Betula platyphylla and Populus davidiana in the area with gradient 〈25°, while forest type B is pure forest or mixed forest composing of superior Quercus mongolica and Betula davurica in the area with gradient 〉25°. Species richness, vegetation coverage, important value, and similarity index of commtmity in different layers （Herb, shrub, small tree, and arbor layers） were investigated and analyzed for the two typical forests. The results show that after fire interference, the species richness and coverage in each layer in forest type A were higher than that in forest type B. Both for forest type A and B, with elapse of post-fire years, the species richness and coverage of herbs and shrubs showed a decline tendency, while those of arbor layer present a rising tendency. Through comparison of the important values of species in each layer and analysis of community structure changes, the dynamic process of post-fire vegetation succession for forest type A and B was separately determined. Post-fire 80 years＇ succession tendency of forest type A is B. platyphylla and Larix gmelinii mixed forest. Its shrub layer is mainly composed of Corylus heterophylla and Vaccinium uliginosum, and herb layer is dominated by Carex tristachya, Athyrium multidentatum, and Pyrola incarnate; whereas, the post-fire 80 years＇ succession of forest type B is Q. mongolica and B. davurica mixed forest. Its shrub layer is mainly composed of lespedeza bicolar and corylus heterophylla and herb layer is dominated by Carex tristachya, Asparagus densiflorus, and Hemerocallis minor.

银西高铁宁夏段荒漠化特征及肥水状态研究

通过银西高铁宁夏段近5年的气象资料,从降雨量、蒸发量、月均温度、极值风速等方面进行分析研究,结果显示:宁夏段干燥度为4.4~6.7,全年最大温差达到34℃,极值风速达到20.8 m/s,整体表现为荒漠化加剧的特征;选取该段高铁路基中6个试验段,对其土壤的含水率、pH值及土壤养分进行现场监测试验研究,结果表明:该区域土壤表现为低含水量、高盐碱、低氮等特征。为下一步边坡生态防护工程提出了选择耐寒抗旱性较强的乔灌木作为高铁路基边坡绿色植物的科学合理的建议,银西高铁边坡生态防护工程研究取得了阶段性的成果。

Natural vegetation recovery on waste dump in opencast coalmine area

The changes of vegetation compositions, plant species diversity, species important value and succession of plant community were studied on waste dumps in Haizhou opencast coalmine which is located in the west of Liaoning Province, China (41°41(-42°56( N, 121°1(-122°56(E). Four kinds of terraces with different ages (5, 10, 20 and 40 years) were selected for investigation of plants. Total of 63 species of natural colonized plants were recorded on the waste dump and they belong to 23 families. The main families were Compositae (15 species), Fabaceae (11 species) and Leguminosae (8 species), which accounted for 54.0% of total species and play an important role in natural vegetation recovery in waste dump area. The dominant species on 5-, 10-, 20-, 40-year-old terraces were Tribulus terrestris + Echinochloa hispidula + Salsola collina, Echinochloa hispidula + Artemisia sieversiana + Artemisia scoparia, Echinochloa hispidula + Clinelymus dahuricus + Artemisia scoparia + Artemisia sieversiana + Melilotus officinalis, Clinelymus dahuricus+Phragmites communis + Echinochloa hispidula+ Setaria viridis, respectively. According to the important value of species calculated. It is determined that Tribulus terrestris can act as pioneer species on waste dump and Clinelymus dahuricus, Phragmites communis and Echinochloah hispidula are important dominant species in vegetation restoration in Haizhou opencast coalmine. The study results can provide scientific basis for selecting and disposing appropriately plant species and rehabilitating vegetation on waste dumps of coalmine.

Floristic and structural analysis of the woodland vegetation around Dello Menna,Southeast Ethiopia

Floristic composition and vegetation structure were described for the woodland vegetation around Dello Menna, Bale zone, southeast Ethiopia. A total 50 （20 m ×20 m） quadrats were sampled to identify and describe plant community types, species diversity, richness and evenness and to relate the identified plant community types with some environ- mental factors and describe the population structure of woody plant species. In each quadrrat, data on species identity, abundance, height and Diameter at Breast Height （DBH） of woody plant species, altitude and slope were recorded. Vegetation classification was performed using PC - ORD software package. Sorensen＇s similarity coefficient was used to detect dissimilarities among communities. Shannon - Wiener diversity index, species richness and Shannon＇s evenness were computed to de- scribe species diversity of the plant community types. Results show that a total of 171 vascular plant species representing 53 families were re- corded. Fabaceae is the dominant family represented by 13 genera and 26 species （15%） followed by Asteraceae, Lamiaceae and Anacardiaceae with eight species each （4.6%）. Based on the results of vegetation classi- fication, three plant communities （Dalbergia microphylla community, Grewia bicolar- Acacia brevispica community, and Combretum molle- Combretum collinum community） are recognized and described. Species richness, diversity and evenness varied among the plant communities.Species richness and diversity exhibit a bell - shaped pattern along alti- tude. Species turn over among communities more or less follow altitud- inal gradients. Tukey＇s pairwise comparison of means among the plant community types shows significant variations in altitude, implying that altitude is one of the most important factors determining the distribution of plant communities. The community Dalbergia microphylla type exhibits the highest species richness and diversity. Analysis of population structure of the dominant species reveals various patterns. Future research directions and recommendations are suggested for the sustainable utilization.

Vegetation and Community Changes of Elm (Ulmus pumila) Woodlands in Northeastern China in 1983-2011

Elm （Ulmus pumila）, widely distributed in the north temperate zone, contributes to a special savanna-like woodland in typical grassland region in the northeastern China. This woodland performs a variety of ecological functions and environmental signifi- cance, such as decreasing soil erosion, stabilizing sand dunes, preserving species diversity. However, in the last approximate 30 years, the species composition, productivity and distribution area of elm woodland has decreased severely. A series of studies have been carried out to find out whether the climate changes or human disturbances caused the degradation of elm woodland and how these factors af- fected elm woodland. In this study, undisturbed, plowing and grazing elm woodland were investigated in 1983 and 2011 by using Point-Centered Quarter method. The relationship between vegetation changes and environmental factors was analyzed by Bray-Curtis ordination. The results show that in 2011, species diversity and understory productivity of undisturbed elm woodland decrease slightly compared to those of undisturbed elm woodland in 1983. However, nearly 60% of the species is lost in the plowing and grazing elm woodland relative to the species undisturbed elm woodland in 1983. Interestingly, plowing stimulates the growth of elm and certain understory species through furrowing soil and accelerating soil nutrient turnover rate. Grazing disturbance not only leads to species loss and productivity decrease, but also induces changes in elm growth （small, short and twisted）. The mean age of the elm was 29 -4- 2 yr in undisturbed and plowing elm woodland, while only 15 yr in the grazing elm woodland. The results of Bray-Curtis ordination analysis show that all sample stands clustered to three groups： Group I including the undisturbed sample stands of 83UE （undisturbed elm wood- land in 1983） and l lUE （undisturbed elm woodland in 2011）; Group II including sample stands of PE （elm woodland disturbed by plowing）; Group III including samples stands of GE （elm woodland disturbed by grazing）. The results indicate that the long time distur- bance of the plowing and grazing have converted elm woodland to different community types. Climate change is not the primary reason causing the degradation of elm woodland, but plowing and grazing disturbance. Both plowing and grazing decrease the vegetation composition and species diversity. Grazing further decreases vegetation productivity and inhibits the growth of elm tree. Therefore, we suggest that reasonable plowing and exclusive grazing would be favorable for future regeneration of degraded elm woodland.

Plant Communities and Factors Responsible for Vegetation Pattern in an Alpine Area of the Northwestern Himalaya

The study intended to describe the alpine vegetation of a protected area of the northwestern Himalaya and identify the important environmental variables responsible for species distribution.We placed random plots covering different habitats and altitude to record species composition and environmental variables.Vegetation was classified using hierarchical cluster analysis and vegetation-environment relationships were evaluated with Canonical Correspondence Analysis.Four communities,each in alpine shrub and meadows were delineated and well justified in the ordination plots.Indicator species for the different communities were identified.Maximum species richness and diversity were found in community IV among shrub communities and community II among the meadows.Studied environmental variables explained 61.5% variation in shrub vegetation and 59.8% variation in meadows.Soil variables explained higher variability (～35%) than spatial variables (～21%) in both shrubs and meadows.Altitude,among the spatial variables and carbon/nitrogen ratio and nitrogen among the soil variables explained maximum variation.About 40% variations left unexplained.Latitude and species diversity among the other variables had significant correlation with ordination axes.Study showed that altitude and C/N ratio played a significant role in species composition.Extensive sampling efforts and inclusion of other non-studied variables are also suggested for better understanding.

Net Primary Productivity and Species Diversity of Herbaceous Vegetation in Banj-oak (Quercus leucotri-chophora A.Camus) Forest in Kumaun Himalaya,India

Net primary productivity and species diversity of herbaceous vegetation of banj-oak （Quercus leucotrichophora A. Camus） forest in Kumaun Himalaya, India were analyzed. Across different growth forms （tall forbs, short forbs, cushion and spreading forbs, grasses）, short forbs were most dominant component during rainy season （1VI=152） and winter season （IVI=167） and grasses during the winter season （IVI=148）. Maximum above-ground production occurred during rainy season （132.5 g m-2） and minimum during winter season （2.8 g m-~）. Below-ground production was maximum （85.9 g m-x） during winter season and minimum （14.9 g m-x） during summer season. Annual net shoot production was 15o g m-~ and below-ground production was 138 g m-~. Of the total input 61% was channeled to above- ground parts and 39% to below-ground parts.

施济普、魏明宝等获本刊优秀论文奖

根据我部决定(见本刊1999年第2期第159页)和有关专家推选评定，施济普、赵崇奖、朱华(的论文《衣裳牢山西坡主要植被类型的特征与物种组成》[2005，11(1)：1～7]和魏明宝、崔长征、方呈祥、张甲耀、王海、王亚芬的论文《铜绿假单胞菌增强型绿色荧光蛋白标记的研究》[2005，11(1)：74～77]获本刊2005年第1期优秀论文奖．本刊将授予两篇论文奖金各500元人民币，授予两篇论文的每在作者获奖证书。

Riparian Vegetation Dynamics Across Two Different Landscapes Along the River Cauvery in the Kodagu Region of Western Ghats

Decades of commercial planting and other anthropogenic processes are posing a threat to the riparian landscapes of the Cauvery river basin, which supports a high floral diversity. Despite this, the habitats in the upstream sections of the River Cauvery are still intact, as they are located in sacred groves. To understand the dynamism of riparian forests exposed to anthropogenic pressures, the upstream stretch of Cauvery extending from Kushalanagara to Talacauvery （~102 km） was categorized into two landscapes： agro ecosystem and sacred （i.e. preserved）. The tree species were sampled using belt transects at 5 km intervals and the regeneration status of endemic species assessed using quadrats. A total of 128 species belonging to 47 families, and representing 1,590 individuals, was observed. Amongst them, 65% of unique species were exclusive to sacred landscapes. A rarefaction plot confirmed higher species richness for the sacred compared to the agro ecosystem landscapes, and diversity indices with more evenness in distribution were evident in sacred landscapes. A significant loss of endemic tree species in the agro ecosystem landscapes was found. Overall, this study demonstrates that an intense biotic pressure in terms of plantations and other anthropogenic activities have altered the species composition of the riparian zone in non-sacred areas. A permanent policy implication is required for the conservation of riparian buffers to avoid further ecosystem degradation and loss of biodiversity.

Ecological Status and Uses of Juniper Species in the Cold Desert Environment of the Lahaul Valley, North-western Himalaya, India

The juniper species Juniperus polycarpos C. Koch, J. indica Bertol. and J. communis L. var. saxatilis （Pallas） are important elements of the forest vegetation in Lahaul valley in the north-western Himalaya. Their ability to grow under the barren and xeric conditions of cold deserts makes them particularly suited for afforestation programmes under these eeologieal conditions. In the Lahaul valley, juniper species are used as subsistence resources and for religious purposes. Excessive removal of juniper wood and leaves by the local population, overgrazing, habitat fragmentation and low regeneration potential are the main obstacles to eonservation of juniper forests in this region. The present study was carried out to assess density, basal area and importance value index （WI） of the local vegetation as well as uses and amounts of juniper wood and leaves removed from the local forests. Pressure on relict juniper forests due to grazing animals and intensive removal of wood and leaves by the loeal population was found to be greater at an altitude above 3,00o m. The results of the study demonstrated that the different juniper speeies were adapted to specific altitude ranges. A higher species density was recorded at lower altitude except for J. indica which was only present at high altitude （〉3,200 m） on south-facing slopes. Density, basal area and IVI of J. polycarpos were higher at Hinsa （2,7oo m） than at Jahlma （3,000 m）. The rapid loss of vegetation due to overuse and habitat degradation has made the eonservation of juniper forests an important priority in the Lahaul valley. J. polycarpos at loweraltitude and J. indica at higher altitude are ecologically the more suitable species for the successful implementation of conservation programmes. The support of rehabilitation programmes by regional authorities is essential for the reestablishment of the local juniper forests.