准噶尔盆地东部卡拉麦里山有蹄类自然保护区主要植物群落及其特征

该文调查了准噶尔盆地东部卡拉麦里山自然保护区的主要植被类型, 通过对54个样地的样方数据分析, 量化描述了这一保护区的主要植物群落特征。结果表明, 这一地区植被主要分为梭梭群系(Form. Haloxylon ammodendron)、驼绒藜群系(Form. Krascheninnikovia ceratoides)、刺木蓼群系(Form. Atraphaxis spinosa)、红砂群系(Form. Reaumuria songarica)、准噶尔沙蒿群系(Form. Artemisia songarica)、刺旋花群系(Form. Convolvulus tragacanthoides)、盐生假木贼群系(Form. Anabasis salsa)、沙生针茅群系(Form. Stipa glareosa)和白茎绢蒿群系(Form. Seriphidium terrae-albae)等9个主要群系, 并进一步划分出16个群丛。     

Distribution,community characteristics and classification of Stipa tianschanica var. gobica steppe in China

戈壁针茅(Stipa tianschanica var. gobica)草原主要分布于荒漠草原区的石质丘陵或石质山坡, 向东可以分布在典型草原区的石质丘陵或山地, 向西也可以分布在荒漠区的石质山坡上。该研究调查了中国戈壁针茅草原的主要植被类型, 通过对115个样地的样方数据分析, 量化描述了这一草原类型的主要植物群落特征。结果表明, 中国戈壁针茅草原共有维管植物272种, 隶属于38科127属; 其中裸子植物3种, 隶属于1科1属; 被子植物269种, 隶属于37科126属, 物种数大于等于10种的科为: 菊科、禾本科、豆科、蔷薇科、百合科、藜科、石竹科; 戈壁针茅草原植物区系的生活型谱以地面芽植物为主, 共178种植物, 占总种数的65.44%; 水分生态类型以旱生植物为主, 共120种, 占总种数的44.12%; 植物区系地理成分上以东古北极分布种和亚洲中部分布种(含其变型)最多, 分别为82种和80种, 占总种数的30.14%和29.41%; 盖度等级划分上以0.1%-1.0%的盖度最多, 共174种, 占总种数的63.97%; 恒有度等级划分上以I级(0-20%)的物种数最多, 共258种植物, 占所有植物种数的94.85%。基于群落调查数据, 按照群落-外貌分类原则, 将戈壁针茅群系划分为8个群丛组106个群丛。     

内蒙古西鄂尔多斯地区半日花荒漠群落特征及其分类

半日花(Helianthemum songaricum)为亚洲中部特有种和古地中海残遗植物, 其群落为内蒙古西鄂尔多斯地区的特有荒漠植物群落。该文以2016-2017年野外调查数据为基础, 结合相关文献资料, 对半日花荒漠群落的分布、群落特征及其分类进行了总结。结果表明: (1)半日花荒漠群落集中分布于黄河以东内蒙古西鄂尔多斯的阿尔巴斯山麓南北部、千里沟; 少量分布于黄河以西贺兰山北端内蒙古乌海市与阿拉善盟交界处及贺兰山最南端的内蒙古阿拉善盟与宁夏交界处明长城沿线的石质残丘。(2)根据样地调查, 半日花荒漠群落记录到种子植物58种, 隶属于17科39属, 其中灌木、半灌木18种, 多年生草本27种, 一年生草本植物13种; 水分生态类型中强旱生植物(15种)和旱生植物(29种)占绝对优势; 区系地理成分以中亚东部成分为主, 其次为古地中海成分和戈壁成分。(3)根据生活型和优势度, 半日花荒漠群落可分为半日花-草本荒漠群丛组、半日花-灌木-草本荒漠群丛组和半日花-半灌木荒漠群丛组, 进一步分为10个群丛。     

中国西南干旱河谷植物群落的数量分类和排序分析

中国西南干旱河谷植被是我国西南横断山区特有的植被类型, 目前关于西南干旱河谷植被还没有整体性的群落类型划分研究。根据对甘肃、四川、云南三省九条主要河流的干旱河谷段野外调查和文献来源的1,339个植物群落样方数据, 采用自适应仿射传播聚类方法, 对我国西南干旱河谷的植物群落进行数量分类, 并采用典范对应分析方法进行排序分析。结果表明: (1)调查样方的植物群落分为7个植被型(稀树草原、肉质灌丛、常绿阔叶灌丛、暖性落叶阔叶灌丛、常绿硬叶林、落叶阔叶林和暖性针叶林), 24个群系, 31个群丛类型。暖性落叶阔叶灌丛是本植被区的代表性植被类型; 分布最广的群系为鞍叶羊蹄甲灌丛(Form. Bauhinia brachycarpa, 样方比例50.9%)、黄茅灌草丛(Form. Heteropogon contortus, 样方比例11.9%)、孔颖草灌草丛(Form. Bothriochloa pertusa, 样方比例5.6%)、黄荆灌丛(Form. Vitex negundo, 样方比例4.2%)、知风草灌草丛(Form. Eragrostis ferruginea, 样方比例3.8%)、车桑子灌丛(Form. Dodonaea viscosa, 样方比例3.4%)、云南松疏林(Form. Pinus yunnanensis, 样方比例3.3%)。(2)冬季低温和降水的季节性是限制干旱河谷植物群落分布的主要气候因子。稀树草原、肉质灌丛是典型的干热河谷植被类型; 暖性落叶阔叶灌丛、常绿硬叶林、常绿阔叶灌丛是干暖河谷植被的优势类型; 暖性针叶林、落叶阔叶林则主要在干温河谷环境占优势。     

Association classification of a 30 hm2 dynamics plot in the monsoon broad-leaved evergreen forest in Pu’er,Yunnan, China

季风常绿阔叶林是我国南亚热带典型的地带性植被, 建立森林动态监测样地是研究生物多样性维持和群落构建机制的重要平台。该文以普洱30 hm ²森林动态监测样地为研究对象, 采用多元回归树、重要值、主成分分析与指示种相结合的方法对样地内750个样方进行群丛数量分类, 以获取季风常绿阔叶林森林植被群丛类型。结果表明: 森林动态监测样地共发现木本植物271种, 隶属于78科178属, 群落类型为短刺锥(Castanopsis echidnocarpa)群系, 可划分4个群丛类型, 分别是珍珠花+毛银柴-短刺锥+泥柯群丛(Lyonia ovalifolia + Aporosa villosa - Castanopsis echidnocarpa + Lithocarpus fenestratus Association)、云南瘿椒树+耳叶柯-短刺锥+西南木荷群丛(Tapiscia yunnanensis + Lithocarpus grandifolius - Castanopsis echidnocarpa + Schima wallichii Association)、大果杜英+黄药大头茶-短刺锥+西南木荷群丛(Elaeocarpus sikkimensis + Polyspora chrysandra - Castanopsis echidnocarpa + Schima wallichii Association)、西桦+尼泊尔桤木-短刺锥+枹丝锥群丛(Betula alnoides + Alnus nepalensis - Castanopsis echidnocarpa + Castanopsis calathiformis Association)。群丛间物种分布存在较多过渡重叠, 指示物种是区分群丛类型的主要依据, 海拔与坡向对群丛分类有较大的影响, 坡度对群丛分类影响较小。     

Species composition and structure characteristics of the major montane shrub communities in the west slope of Helan Mountains,Nei Mongol,China

灌丛是贺兰山最主要的植被组分, 但关于该地区灌丛群落的专门研究并不多见。为了解该地区灌丛资源的分布及生长状况, 该研究对内蒙古贺兰山国家级自然保护区内主要的山地灌丛群落进行样方调查, 通过分析样方数据, 量化描述了各群落的基本特征。结果表明: 贺兰山自然保护区沿海拔梯度主要有准噶尔栒子群系(Form. Cotoneaster soongoricus)、紫丁香群系(Form. Syringa oblata)、小叶金露梅群系(Form. Potentilla parvifolia)、虎榛子群系(Form. Ostryopsis davidiana)、小叶忍冬群系(Form. Lonicera microphylla)、银露梅群系(Form. Potentilla glabra)、山生柳群系(Form. Salix oritrepha)和鬼箭锦鸡儿群系(Form. Caragana jubata) 8种主要的山地灌丛群系。     

新疆奇台荒漠类草地自然保护区主要植物群落及其特征

该文调查了新疆奇台荒漠类草地自然保护区的主要植被类型, 通过对65个样地的样方数据分析, 量化描述了该保护区的主要植物群落特征。该保护区内主要包括梭梭荒漠(Haloxylon ammodendron Semi-Arbor and Shrub Desert Alliance)、膜果麻黄荒漠(Ephedra przewalskii Simi-Arbor and Shrub Desert Alliance)、裸果木荒漠(Gymnocarpos przewalskii Simi-Arbor and Shrub Desert Alliance)、红砂荒漠(Reaumuria soongarica Simi-Arbor and Shrub Desert Alliance)、戈壁藜荒漠(Iljinia regelii Semi-Shrub and Herb Desert Alliance)、短叶假木贼荒漠(Anabasis brevifolia Semi-Shrub and Herb Desert Alliance)、短穗柽柳落叶阔叶灌丛(Tamarix laxa Deciduous Broadleaf Shrubland Alliance)、盐爪爪荒漠(Kalidium foliatum Semi-Shrub and Herb Desert Alliance)、灌木亚菊荒漠(Ajania fruticulosa Semi-Shrub and Herb Desert Alliance)、芨芨草草地(Achnatherum splendens Tussock Grassland Alliance)、窄颖赖草草地(Leymus angustus Rhizome Grassland Alliance)和芦苇草地(Phragmites australis Rhizome Grassland Alliance)共12个主要群系, 并进一步划分出15个群丛。     

华北地区主要灌丛群落物种组成及系统发育结构特征

灌丛在中国北方广泛分布, 研究其物种组成特征及构建机制对植被恢复有重要意义。群落系统发育结构能有效反映群落组成的生态过程, 对揭示群落构建机制具有重要作用。该研究利用华北地区自然植物群落资源综合考察数据库的灌丛数据, 分析了中国华北地区主要灌丛群落的分布情况、物种组成及其系统发育结构特征。同时, 结合WorldClim数据库中的气候因子利用逐步回归和一般线性模型分析了气温和降水对灌丛不同垂直结构层物种系统发育结构特征的影响。经统计, 共调查木本植物75科207属570种; 草本植物99科491属1 221种。按植被型和群系类型分类后, 共有5种植被型, 195个群系, 其中分布最多的群系类型为虎榛子(Ostryopsis davidiana)灌丛、荆条(Vitex negundo var. heterophylla)灌丛、荆条+酸枣(Ziziphus jujuba)灌丛和沙棘(Hippophae rhamnoides)灌丛。整体上, 草本层的物种丰富度高于灌木层。草本层的系统发育结构表现为发散模式, 而灌木层的系统发育结构表现为聚集模式, 且不同植被型灌丛的系统发育结构不同。气候因子的变化对灌木层和草本层系统发育结构都表现出了明显的影响, 但对灌木层的影响要强于对草本层的影响, 且气候因子和植被型、群系类型都有明显的交互作用。分析结果表明, 区域尺度上气温和降水的变化会影响灌丛群落不同结构层的系统发育结构特征, 且对不同的植被型和群系类型的影响不同。     

Diversity of dark septate endophyte in the roots of Ammopiptanthus mongolicus and its companion plants

Aims Dark septate endophytes (DSE) extensively colonize in plant root tissues in different ecosystems. However, our understanding of the ecological significance of DSE in semiarid and arid lands is limited. The main objective of this study was to compare the community composition and species diversity of DSE in Ammopiptanthus mongolicus and its companion plants in desert habitats. Methods Healthy root samples of Ammopiptanthus mongolicus’s companion plants, Artemisia desertorum, Caragana rosea, Nitraria tangutorum and Caragana korshinskii, were collected separately from four main locations of Ammopiptanthus mongolicus plantation in Dengkou of Nei Mongol, Minqin of Gansu, Yinchuan and Shapotou of Ningxia in July 2013. Important findings A total of 103 strains belonging to seven species (i.e Alternaria, Curvularia, Embellisia, Phialocephala, Phoma, Podospora and Pleosporales) of DSE were isolated from the four types of companion plants by means of morphological identification and molecular identification. Among the seven genera, Alternaria, Embellisia, Curvularia and Podospora are found for the first time in desert ecosystems. Ammopiptanthus mongolicus and its companion plants at the same site had significantly different community composition of DSE. Ammopiptanthus mongolicus and its companion plants at different sites had significantly different DSE diversity index. The colonization and species richness of DSE, especially the species and the quantity of spores were higher in roots of Ammopiptanthus mongolicus than in its companion plants. This study supports the results that DSE can form a better symbiotic relationship with the roots of Ammopiptanthus mongolicus than with its companion plants, and can enhance the ecological adaptability of Ammopiptanthus mongolicus to the extreme desert environment.     

Spatial pattern of riparian vegetation in desert of the lower Tarim River basin

AimsRevealing the spatial pattern of riparian vegetation in hyper-arid regions can improve our understanding on the water relations of riparian vegetation in the desert watershed ecosystem, and also can provide valuable scientific guidance for desertification control and water resources management of watershed of the arid region in northwestern China. This research objective is to show the spatial distribution and structures of typical riparian vegetation in hyper-arid desert watershed from regional and overall perspective.Methods Based on Landsat-8 OLI remote sensing images and a large number of field vegetation surveys, the supervised classification method was used to distinguish three main vegetation categories in the lower Tarim River basin: Tamarix thicket, Populus euphratica woodland, and Phragmites australis grassland. The leaf area index (LAI) of Tamarix thickets and Populus euphratica woodlands were inverted by using the remote-sensed LAI inversion empirical model that we developed.Important findings Supervised classification supporting abundant information of ground objects by remote sensing was an effective method to determine desert riparian vegetation categories in arid desert regions. The area was 336.4 km² for the Populus euphratica woodlands and 405.3 km² for the Tamarix thickets, respectively. The Tamarix thickets had a wider distribution range while the Populus euphratica woodlands grew near the river channel. The overall LAI of the riparian vegetation was low. The average LAI value was 0.253 for the Tamarix thickets and 0.252 for the Populus euphratica woodlands. The areas of vegetation with the LAI value of less than 0.5 accounted for 92.4% and 90.1% of the total area of the Tamarix thickets and the Populus euphratica woodlands, respectively. The statistic results showed that large spatial variability of the riparian vegetation LAI existed. The spatial variability of the Populus euphratica woodlands was larger than that of the Tamarix thickets. The LAI values of the riparian vegetation had a significant negative exponential relationship with the distances away from the river channel. The LAI values declined rapidly within the distance of 1 km from the river channel and they were generally lower than 0.1 when the distances beyond 1 km, which indicated that the riparian vegetation was mainly distributed within 1 km from both side of the river. This research indicated three basic characteristics of the spatial pattern in riparian vegetation from hyper-arid desert regions, including overall sparse spatial distribution, high spatial variability and negative exponential relationship between LAI and distance away from the river channel.     

Preliminary study on pollen distribution in the surface soil of the Turpan region in the southern slope of Tianshan Mountains,Xinjiang, China

Aims Our main purposes were to analyze the relationship between vegetation and pollen in the surface soil of the Turpan region, which is located in the southern slope of the eastern Tianshan Mountains, and to compare different pollen assemblages between the Turpan region and the northern slope of the Tianshan Mountains.Methods We collected 36 modern pollen samples and carried out modern vegetation survey in the Turpan region along an altitudinal gradient from 2 000 m to -154 m. Detrended correspondence analysis and Redundancy analysis were applied to analyze the distribution pattern of pollen in surface soils. Important findings We divided the pollen spectra into four pollen assemblage zones (mountain desert-steppe and desert, Gobi gravel, typical desert and salt mash vegetation), corresponding to the major vegetation types in the Turpan region. When compared with the northern slope, the characteristics of pollen assemblages in the mountain desert-steppe and desert were similar to those in the forest-steppe on the northern slope of the Tianshan Mountains; the pollen assemblages in the Gobi gravel and the typical desert seemed to be more consistent with those in the typical desert on the northern slope; however, no analogue was found in the salt mash vegetation. Obviously, the vertical pollen spectra in Turpan region were incomplete, lacking typical forest and Artemisia desert pollen zones. Besides, similar pollen zones in the Turpan region were found at an elevation of about 300 m higher than those in the northern slope. It is remarkable that the typical tree pollen, such as Picea and Pinus, showed their extra representation in the Turpan region. On one hand, the valley forest on the southern slope of the Tianshan mountains played an important role in pollen dispersal. On the other hand, with the cold air on the northern slope over the Tianshan Mountains, pollen may be carried and deposited in the Turpan region. The rivers feeding into Aiding Lake in the Turpan region may also contribute to the distribution of Picea and Pinuspollen. Lots of pollen studies have shown that the ratio of Artemisia to Chenopodiaceae (A/C) can be used as a good indicator of the degree of humidity in the semi-arid and arid areas. Our study revealed that A/C can roughly reflect the characteristics of the desert zone in the study area. The results of Redundancy Analysis ordination on pollen assemblages and environmental factors (mean annual temperature (MAT), mean annual precipitation (MAP) and altitude (ALT)) revealed that MAP was the main environmental factor affecting the pollen assemblages in the surface soil in the Turpan region and had more significant effects on the distribution of Nitraria pollen than on the distribution of Artemisia and Chenopodiaceae.     

Characteristics of plant communities containing rare conifers in Poyang Lake Basin,China

The endangerment mechanism of rare conifer species is a very critical problem in conservation biodiversity. Thus, the studies on the protection of the rare and endangered coniferous trees have received extensive attention. The objective of this study was to understand the survival and distribution of the rare coniferous tree species in natural forests of the Poyang Lake Basin. Field investigations on plant communities were conducted in 21 plots from Oct. 2014 to Oct. 2015. These plots were distributed in the Nanling Mountains, Luoxiao Mountains, Wuyi Mountains, Huangshan Mountains, and Jiuling Mountain. The dimensions of each plot were 20 m × 20 m. Community species composition and quantitative characteristics in each plot were recorded. The importance values of trees, shrubs and herbs were computed, respectively. The community types and structural properties were analyzed. A total of 23 sets of community sampling data were obtained in details. A number of 11 species of rare conifers were found in 14 different formations. Rare conifer trees mainly occurred in the communities as co-edificatos or companion species. The formations included Form. Taxus wallichiana var. mairei, Form. Pseudotsuga sinensis, Form. Fokienia hodginsii and Form. Torreya grandis, where the dominant species was coniferous trees. In conclusion, our study provides valuable field investigation data of rare coniferous in Poyang Lake basin, which could provide insight into the protection and management of these species.     

新疆阿尔泰红山嘴地区的表土孢粉与现代植被

在新疆阿尔泰山中段的红山嘴地区选取一条沿海拔745-2 413 m的不同植被带群落样方进行调查, 对应采集37个表土样品进行孢粉统计和排序分析, 初步探究了红山嘴地区的植被与表土孢粉之间的对应关系, 并将之与新疆阿尔泰西部的喀纳斯西坡孢粉垂直带进行对比。结果表明, 红山嘴地区表土孢粉谱依照海拔高度自上而下划分为4个孢粉组合类型, 分别对应亚高山草甸、山地森林、灌丛草原和荒漠草原。乔木植物中云杉属(Picea)和松属(Pinus)花粉, 灌木植物中麻黄属(Ephedra)及草本植物中的苋科和蒿属(Artemisia)因受到自然风力、水流及人为活动的影响, 表现出明显的超代表性; 乔木植物中的落叶松属(Larix)花粉, 草本植物中的禾本科及莎草科花粉, 却在其自身为优势种的群落中呈现低代表性; 蒿属与苋科花粉百分含量的比值(Ar/Am)能较好地反映该区气候垂直带的干湿状况, 灌丛草原带的Ar/Am低, 在一定程度上反映了人类活动对草原灌丛化的影响。与新疆阿尔泰西部的喀纳斯西坡孢粉垂直带相比, 红山嘴垂直带的孢粉类型偏少, 同时相似的孢粉带在该区的分布高度比喀纳斯西坡高。此外, 排序分析(RDA)结果表明, 年降水量是影响该区表土孢粉组合的主要环境因子。     

鄂西南亚高山不同覆被类型泥炭藓沼泽湿地甲烷排放特征及其环境影响因子

沼泽湿地是大气甲烷(CH₄)的重要来源, 但有关亚热带亚高山沼泽湿地CH₄排放的研究却鲜有报道, 特别是对不同覆被类型泥炭藓沼泽湿地CH₄排放量的精确估算及其与环境因子的关系尚不清楚。该研究选择鄂西南亚高山泥炭藓沼泽湿地为研究区域, 于2018年11月-2019年10月间, 使用静态箱-气相色谱仪法原位测定3种覆被类型泥炭藓沼泽湿地CH₄通量, 同步记录大气和地下5 cm土壤的温度以及地下水位变化。结果表明: (1)光照下, 裸露地(B)、泥炭藓(Sphagnum paluster)(S)、金发藓(Polytrichum commune)(P) 3种覆被类型泥炭藓沼泽湿地CH₄-C通量全年变化范围分别为: 0.012-1.372、0.022-1.474、0.027-3.385 mg·m^-2·h^-1; 遮光处理下, B、S、P 3种覆被类型泥炭藓沼泽湿地CH₄-C通量的全年变化范围分别为: 0.012-1.372、0.009-1.839、0.017-2.484 mg·m^-2·h^-1, 均为CH₄排放源。同时, 光照条件下不同覆被泥炭藓沼泽湿地CH₄排放量略大于黑暗条件, 但差异不明显。(2)不同覆被类型泥炭藓沼泽湿地CH₄排放存在明显的季节变化规律, 即: 夏季>秋季>春季>冬季, 其中夏季CH₄排放量显著大于其他季节, 占全年的57%-84%。该研究发现泥炭藓沼泽湿地CH₄通量均与气温和地下5 cm土壤温度极显著相关, 且CH₄排放量随温度升高呈指数增加, 表明温度是影响泥炭藓沼泽湿地CH₄排放时间变化的主要环境因子。(3) 3种覆被类型泥炭藓沼泽湿地的年平均和年累计CH₄排放量均依次为: P > S > B, P显著大于B。该研究发现植被类型与泥炭藓沼泽湿地CH₄排放量存在显著相关性, 表明覆被类型是影响泥炭藓沼泽湿地CH₄排放量空间变异的主要因子。(4) 3种覆被类型泥炭藓沼泽湿地CH₄排放量均与地下水位变化不相关。该研究进一步丰富了泥炭藓沼泽湿地CH₄排放规律, 同时也为区域碳循环提供了详实的基础数据。     

宁夏贺兰山斑子麻黄荒漠群落特征

斑子麻黄(Ephedra rhytidosperma)群落是贺兰山山麓特有荒漠植物群落。该研究于2019年调查了16个斑子麻黄典型群落, 分析了物种组成的区系特征, 运用TWINSPAN软件对16个斑子麻黄群落进行了分类。结果表明: 1)斑子麻黄群落物种组成以禾本科、菊科、豆科和蒺藜科植物为主, 隶属13科24属27种。2)斑子麻黄荒漠群落生活型以多年生草本(44.44%)和灌木(29.63%)为主; 区系以古地中海成分(44.44%)和东亚成分(33.33%)为主; 水分生态类型以旱生(40.74%)和强旱生(37.04%)为主。3)根据生活型和优势度, 斑子麻黄群落可分为斑子麻黄-半灌木荒漠(Ephedra rhytidosperma - Semi-Shrub Desert)和斑子麻黄-草本荒漠(Ephedra rhytidosperma - Herb Desert) 2个群丛组, 进一步划分为3个群丛: 斑子麻黄-刺旋花-兴安胡枝子 半灌木与草本荒漠(Ephedra rhytidosperma - Convolvulus tragacanthoides - Lespedeza davurica Semi-Shrub and Herb Desert)、斑子麻黄-刺旋花-中亚细柄茅 半灌木与草本荒漠(Ephedra rhytidosperma - Convolvulus tragacanthoides - Ptilagrostis pelliotii Semi-Shrub and Herb Desert)和斑子麻黄-中亚细柄茅 半灌木与草本荒漠(Ephedra rhytidosperma - Ptilagrostis pelliotii Semi-Shrub and Herb Desert)。     

Community characteristics and spatial distribution of dominant tree species in a deciduous broad-leaved forest of Muzhaling,Henan, China

Aims The objective of this paper is to quantify the species composition and spatial distribution pattern in a deciduous broad-leaved forest in temperate to subtropical ecological transition zone.
Methods In this study, a 3-hm² forest was selected in the temperate to subtropical ecological transition zone to analyze the community species composition, structure of diameter at breast height, community classification and spatial distribution pattern of dominant tree species.
Important findings Our results showed that in the plot there were 85 species, 52 genera and 31 families, mainly composed of Betulaceae, Celastraceae, Caprifoliaceae, Salicaceae and Aceraceae. Quercus aliena var. acuteserrata and Pinus armandii are dominant species of the community tree layer. The rare species and occasional species accounted for 20.0% and 28.24% of total species respectively. Size distribution of all species showed an invert J-shape, which indicates that the community is in a stable and normal growth status. Using multiple regression trees, the community in this plot can be divided into four categories: 1) Quercus aliena var. acuteserrata + Pinus armandii + Litsea tsinlingensis + Cerasus clarofolia + Lindera obtusiloba; 2) Quercus aliena var. acuteserrata + Salix chaenomeloides + Sorbus hupehensis; 3) Quercus aliena var. acuteserrata + Ailanthus altissima + Cerasus clarofolia + Litsea tsinlingensis; 4) Quercus aliena var. acuteserrata + Fraxinus chinensis + Litsea tsinlingensis + Philadelphus incanus. Under the completely random distribution model, the main species in the plot display clustered distributions, with the different species occurring in different habitat types, showing obvious terrain habitat preferences. However, under the heterogeneous Poisson distribution model, these species at different scales are distributed randomly or regularly. This study helps to understand the plant community species composition of the Muzhaling World Geopark, community structure and community distribution. The results show that the terrain habitat heterogeneity is an important factor influencing the spatial distribution of the species. The present work improves the understanding of plant community in Muzhaling World Geopark, and provides technical reference for biodiversity conservation and forest management of this area.     

山东蒙山6种造林树种40余年成林效果评价

植被恢复一直是恢复生态学研究的核心问题和首要解决目标。该文拟评估山东蒙山森林植被恢复与重建的现状和程度, 评价不同造林树种对植物多样性的影响, 筛选一批造林工具种, 为今后沂蒙山区森林植被恢复与重建的调控和预测提供依据。采用样地法和样方法, 选择林龄超过40年的6种主要人工林为样地, 采用典型取样法进行林内调查。根据乔木层、灌木层和草本层的物种丰富度、Shannon-Wiener多样性指数、Simpson多样性指数和Pielou均匀度指数评价物种多样性, 分析乔木径级分布, 判断植物发展类型。结果表明: 乔木层、灌木层和草本层的4种多样性指数较为一致地显示赤松(Pinus densiflora)、栓皮栎(Quercus variabilis)、黑松(Pinus thunbergii)、日本落叶松(Larix kaempferi)和刺槐(Robinia pseudoacacia)的成林效果较好, 油松(Pinus tabuliformis)相对较差。6种人工林群落灌木层和草本层的4种多样性指数基本无显著差异, 而乔木层中, 油松人工林群落的4种多样性指数与黑松人工林、刺槐人工林、栓皮栎人工林和日本落叶松人工林存在部分显著差异(p < 0.05)。从整体上看, 人工林群落灌木层发育最好, 4种多样性指数均为灌木层>乔木层>草本层, 且差异大多极显著(p < 0.01)。研究发现: 乔木扩展种29种、隐退种3种、稳定侵入种9种和随机侵入种11种, 表明人工林群落正处于向森林演替的过程中。数据显示: 3种隐退种赤松、油松和日本落叶松均为群落局部优势种, 赤松和油松种群更新困难, 日本落叶松完全没有更新幼苗。作者认为林下发达的灌草层可能是阻碍针叶林天然更新的关键因素。评估筛选出15种造林工具种: 早期开荒工具种(A类) 7种和后期顶级工具种(B类) 8种。其中A1类(建群种) 2种: 赤松和油松, A2类(伴生种) 5种: 黄檀(Dalbergia hupeana)、花曲柳(Fraxinus rhynchophylla)、君迁子(Cerasus serrulata)、山合欢(Albizia kalkora)和鹅耳枥(Carpinus turczaninowii); B1类(建群种) 2种: 栓皮栎和麻栎(Quercus acutissima), B2类(伴生种) 6种: 水榆花楸(Sorbus alnifolia)、槲树(Quercus dentata)、山樱花(Diospyros lotus)、小叶朴(Celtis bungeana)、大叶朴(Celtis koraiensis)和三桠乌药(Lindera obtusiloba)。     

Effects of a winter wildfire on plant community structure and forage quality in subalpine grassland of western Sichuan,China

火是继土壤、水分、温度之后, 塑造地表植被的主要力量。该文以2010年“12·5”冬草场火烧事件为背景, 通过对比川西亚高山草地火烧区域和未火烧区域火后第一年植被群落结构和牧草质量, 探讨亚高山草地植被对冬季火烧的响应机制。通过物种多样性分析、双向指示种分析(TWINSPAN)和干重等级法(dry-weight-rank)分析发现, 冬季火烧未改变植被的生物多样性、均匀度和物种丰富度, 却改变了植被群落结构的物种组成。冬季火烧导致一年生禾草、一年生杂草、灌木等3种生活型植物的数量和生物量增加; 多年生杂草数量减少, 生物量增加; 多年生禾草数量和生物量减少。冬季火烧也极大地减少了可食禾草的比例, 增加了各种杂草的生物量比例。此次火烧事件降低了细柄草(Capillipedium parviflorum)和早熟禾(Poa sp.)等可食禾草的竞争能力, 增加了一些杂草(如火绒草(Leontopodium leontopodioides)、白莲蒿(Artemisia sacrorum)、草玉梅(Anemone rivularis)等)在资源竞争中的相对优势, 最终表现为火后牧草的可食性下降。     

《中国植被志》的植被分类系统、植被类型划分及编排体系

植被志(vegegraphy)是基于植被调查资料, 全面记叙植被的群落外貌、种类组成、结构和功能、生境条件, 以及地理分布等特征, 并对同类植被进行归纳和总结的志书。“植被志”的英文译为“vegegraphy”, 是本文的新造词, 它是由“vegetation”的词头“vege-”和英文后缀“-graphy” (记叙之意)组成的合成词。《中国植被志》的研编是一项时间紧迫、内容复杂、工作量浩繁的重大科学工程。它的完成将极大提升中国植被科学和生态学的研究水平, 并为中国植被资源的合理利用、生物多样性保护及生态环境治理等提供不可或缺的基础资料。本文首先简述了植被的基本特征(主要包括外貌特征、种类组成、群落结构以及动态变化等)和国内外植被调查的进展情况, 简要回顾了中国植被分类系统的研究历史, 并对以往的分类系统进行了若干修订。在此基础上, 着重讨论并提出了《中国植被志》卷册编排体系和用于《中国植被志》研编的植被类型划分方案。在对植被分类系统的修订方面, 主要对高级分类单位及相对应的英文名称进行了讨论和修订。按照本文修订的分类系统, 中国植被的分类单位及其对应的英文名称分别是: 植被型组(Vegetation Formation Group)、植被型(Vegetation Formation)和植被亚型(Vegetation Subformation)、群系组(Alliance Group)、群系(Alliance)和亚群系(Suballiance)、群丛组(Association Group)以及群丛(Association)。在植被型组中, 划分为9类: 森林、灌丛、草本植被、荒漠、高山冻原与稀疏植被、沼泽与水生植被、农业植被、城市植被及无植被地段。关于《中国植被志》的卷册编排和“植被类型”划分, 首先按高级分类单位——植被型划分相应的“卷”; 在此框架下, 模糊“植被亚型”、“群系组”和“群系”的概念, 确定“植被类型” (Vegetation type), 并将其作为植被志各卷中的“册”。这样处理不仅保证了研编工作的可操作性, 也保持了同一卷册中特定植被类型的完整性。《中国植被志》编排体系中的“植被类型”的划分很重要, 它是指具有相同建群种及相同优势类群(如种、属)的植被组合, 但它不是严格意义上的植被分类单位。“植被类型”的划分遵循“优势类群及生活型的同一性, 生境条件的相对重要性, 植被特征及用途的差异性, 以及突出植被志的应用性”等原则。按该编排体系, 《中国植被志》将由48卷约110册组成。     

Responses of plant community biomass to nitrogen and phosphorus additions in natural and restored grasslands around Qinghai Lake Basin

Aims Plant biomass reflects the primary productivity of community vegetation, and is the main resource of carbon input in the terrestrial ecosystem. It is usually limited by nitrogen (N) and phosphorus (P) availability in the soil. Alpine grassland around Qinghai Lake Basin has experienced extensive land-use changes due to the cultivation of native grassland and vegetation recovery on cropped land. In this experiment, two grassland types were chosen, natural alpine grassland (NG) and its adjacent restored grassland (RG), to determine the responses of plant community biomass to N and P additions with different land-use. Methods NH₄NO₃ and Ca(H₂PO₄)₂·H₂O were added in a completely randomized block design, with medium levels of 10 g N·m^-2 and 5 g P·m^-2. Soil NO₃^--N and available P contents, and the plant community biomass were measured in the two grasslands. Two-way ANOVA was used to determine the effects of nutrient additions on all measured indicators, and regression analysis was used to analyze the correlations between plant biomass and soil NO₃^--N and available P contents.Important findings Results showed: (1) N and P additions both increased grass biomass in the NG, and significantly elevated the total aboveground biomass, with the promoting effect of N addition higher than that of P addition; N addition significantly increased both grass and forb biomass in the RG, and markedly promoted the total aboveground biomass, while P addition had no effects on the functional groups and total aboveground biomass (p > 0.05). (2) N and P additions both had no effects on the belowground and total biomass in the NG, whereas N addition significantly increased the total biomass by 34% in the RG, which suggested that the effect of N limitation on the vegetation primary productivity was stronger in the RG at present stage. (3) The aboveground biomass in the NG increased with soil NO₃^--N content (p < 0.05), and the above- and below-ground as well as the total biomass were all positively correlated with soil NO₃^--N content in the RG (p < 0.01). These results indicated that the plant growth in alpine grassland around Qinghai Lake Basin was prone to N limitation, and the effect of P limitation changed with land-use. Soil available N might be the key limiting factor for vegetation restoration and reconstruction in the RG. The “Grain for Green” project (the land-use policy) and atmospheric N deposition are benefiting both plant growth and C accumulation in the alpine grassland ecosystem around Qinghai Lake Basin.