四川卧龙地区珙桐群落特征的初步研究

珙桐是我国特产的第三纪古热带区系的孑遗植物。本文通过对珙桐群落的区系组成、地理成分和林木层的优势度分析,说明该群落是一种种类丰富,古老成分较多,并以珙桐为优势的具有残遗性质的混交林。通过生活型、叶级谱、叶型与叶质的分析,珙桐林是一种中亚热带亚高山垂直带谱上的典型的常绿、落叶阔叶混交林植被。此外,对群落结构和动态也作了一些分析。     

后河自然保护区常绿落叶阔叶混交林群落学特征研究

研究了后河国家级自然保护区常绿落叶阔叶混交林的区系特点、群落学特征。结果表明 :后河国家级自然保护区常绿落叶阔叶混交林群落物种丰富 ,有 110科 2 88属 5 34种 ,科的分布型以热带类型为主 ,属的分布型温带类型占优势 ,反映该群落区系以温带为主的亚热带区系特点 ;该混交林主要由以单叶、中型叶及非全缘叶为主的常绿、落叶阔叶高位芽植物组成 ,群落层次分明 ,从上至下 ,落叶阔叶树种所占比例逐渐减少 ,常绿阔叶树种比例逐渐增加 ;除两低海拔样地外 ,多样性变化幅度较小 ,各样地的物种多样性指数变化趋势基本一致。     

后河自然保护区常绿落叶阔叶混交林落学特征研究

研究了后河国家级自然保护区常绿落叶混交林的区系特点,群落学特征,结果表明：后河国家级自然保护区常绿叶阔叶混交林群落物种丰富,有110科288属534种,科的分布型以热带类型为主,属的分布型温带类型占优势,反映该群落区系以温带为主的亚热带区系特点;该混交林主要由以单叶,中型叶及非全缘叶为主的常绿,落叶阔叶高位芽植物组成,群落层次分明,从上至下,落叶阔叶树种所占比例逐渐减少,常绿阔叶树种比例逐渐增加,除两低海拔样地外,多样性变化幅度较小,各样地的物种多样性指数变化趋势基本一致。     

广西金钟山自然保护区主要植被类型的特征

金钟山自然保护区计有种子植物101科273属514种,落叶栎林分布面积最广。随海拔升高,植被依次呈现出4个分布带:沟谷落叶阔叶林、沟谷常绿阔叶林、常绿落叶阔叶混交林和落叶阔叶林、山地苔藓矮林和山地常绿阔叶林。该区主要有4个分布区类型:世界分布、热带分布、温带分布和中国特有分布,其中热带分布占总属数的75.21%,表明本保护区的植物分布具有热带性质。其天然植被类型可划分为5个植被型组,7个植被型含暖性针叶林、暖性落叶阔叶林、常绿落叶阔叶混交林、常绿阔叶林、竹林和草丛,2个植被亚型含南亚热带山地常绿阔叶林、山顶阔叶矮林,以及33个群系。     

八大公山中亚热带山地常绿落叶阔叶混交林物种组成与结构

山地常绿落叶阔叶混交林在我国主要分布在中亚热带1000～2000 m中山地带。八大公山位于武陵山系北端,中亚热带北缘,具有保护较好的典型山地常绿落叶阔叶混交林。为了研究常绿落叶阔叶混交林动态和川东-鄂西植物多样性形成及维持机制,按照CTFS（Center for Tropical Forest Science）样地建设标准,中国科学院武汉植物园于2010-2011年在湖南八大公山（Badagongshan,BDGS）国家级自然保护区建立了一个25 hm2（500 m×500 m）中亚热带山地常绿落叶阔叶混交林动态监测样地（Forest Dynamic Plot）。本研究以样地内所有胸径（DBH）≥1 cm的木本植物（不含竹藤）为研究对象,分析该样地区系成分、群落组成、垂直结构、径级结构和空间分布。结果表明：八大公山样地属于典型的山地常绿落叶阔叶混交林,植物以泛热带分布科（24.50%）和北温带分布属（24.56%）占优势,包括9种珍稀濒危植物。样地内木本植物合计53科、114属、238种（含种下分类单位）,186556株存活个体。落叶树144种,常绿树94种。壳斗科（Fagaceae）、杜鹃花科（Ericaceae）、樟科（Lauraceae）和山茶科（Theaceae）占据优势;个体数超过1000的有38个物种,以常绿树种（63.16%）为主;稀有种（〈25株）103个（占样地物种总数43.28%）。群落垂直结构可分为乔木层（优势树种多脉青冈Cyclobalanopsis multinervis和亮叶水青冈Fagus lucida）、亚乔木层（优势种长蕊杜鹃Rhododendron stamineum和黄丹木姜子Litsea elongata）和灌木层（优势种短柱柃Eurya brevistyla和薄叶山矾Symplocos anomala）。个体数超过1000的树种和稀有种主要来自灌木层。由于生长型限制,样地内树种平均胸径较小（5.41 cm）,DBH〈5 cm的个体占优势（68.40%）。主要优势树种的径级结构呈现倒J型。     

黄岗山西北坡森林垂直带群落特征及区系分析

为研究森林垂直带的群落组成特征及其植物地理区系成分,于黄岗山西北坡从低海拔至高海拔设置5个群落带,依次为常绿阔叶林、常绿落叶阔叶混交林、针阔混交林、针叶林、中山苔藓矮曲林。通过统计分析,结果显示,黄岗山垂直带森林具有典型的中亚热带地带性植被特点,以常绿阔叶树和常绿针叶树为主要优势种;种的相似性指数表明,不同植被群落间物种组成具有较大的差异性,同时也说明黄岗山森林丰富的物种多样性;植物区系地理成分复杂多样,以热带成分为主,并具有由热带向温带过渡的性质。     

贵州省宽阔水亮叶水青冈林的数量分类

亮叶水青冈(Fagus lucido) 是我国水青冈属植物中分布较广的一种,常与一些耐寒的常绿阔叶树种构成落叶、常绿阔叶混交林,或形成单优群落镶嵌于落叶、常绿阔叶混交林带内,在较高的山体上亦与常绿针叶,常绿、落叶阔叶树种形成针阔混交林。各种亮叶水青冈林是亚热带山地植被垂直带谱的一个重要组成分子。贵州省宽阔水林区保存有集中连片,面积较大,原生性较强的亮叶水青冈林,是该林区森林植被的主体。本文是应用聚类分析和极点排序的数量分类方法对宽阔水林区亮叶水青冈林类型进行划分并对类型的分布规律、优势种的分布格局和生境梯度的变化进行分析的初步研究。     

浙江仙居俞坑森林群落研究

浙江仙居俞坑森林群落植物种类丰富, 优势种不明显, 群落中植物种类以常绿阔叶树种为主, 落叶阔叶成分也有一定比例。各样地植物种类相似性很低, 组成很不一致。群落垂直结构复杂, 地上成层明显。群落乔木层物种多样性指数较高, 各样地间多样性指数测值变幅较大。样地内的优势种群中常绿阔叶树种的年龄结构呈稳定型或增长型、而落叶树种的年龄结构呈衰退型。乔木层各优势种群的分布格局多呈随机分布或均匀分布。     

峨眉山世界遗产地表土孢粉组合及其生态和古环境启示

通过峨眉山40个样点表土孢粉组合及其与植物群落之间关系的分析,结果表明:(1)花粉组合中木本植物含量(83.3%)占绝对优势,松属、杉科、桤木属、蔷薇科、桦属、枫杨属、蒿属、毛茛科和水龙骨科为主要孢粉类型;(2)中山常绿阔叶林花粉组合未能反映植被的群落特征;低山常绿阔叶林间人工次生林和常绿落叶阔叶混交林花粉组合只能反映母体植被的部分组成;针叶林花粉组合基本可以指示母体植被的群落特征;灌丛草甸花粉组合能够较好地反映母体植被的群落组成;针阔混交林花粉组合不仅可以很好地指示群落特征,花粉高含量类型还可以与植物群落优势种很好地对应;(3)主要花粉类型冷杉属、杜鹃花科、蔷薇科、珙桐属、槭属和盐肤木属具低代表性;枫杨属、栲属/柯属、桤木属和杉科花粉具超代表性;(4) DCA表明,通过花粉百分含量,能较好地区分人类扰动植被、阔叶林和针叶林,但常绿阔叶林、常绿落叶阔叶混交林和针阔混交林之间,针叶林和灌丛草甸之间难以区分;(5)利用孢粉学恢复热带亚热带常绿阔叶代表类群樟科群落和第三纪孑遗落叶阔叶属种珙桐群落时,受其主体植物花粉外壁薄,易破碎影响,原生植被优势种缺失;因此,孢粉实验改良和保存环境研究,与其他生物学指标(植物大化石和气孔器)综合分析在重建古植物群落中具有重要意义;(6)植物(如冷杉)花粉含量一定程度上能够指示其林分结构。本研究可为热带亚热带山地及相似地区利用孢粉学进行地质时期气候与环境重建提供理论支持和基础资料,并对植被生态恢复提供实践和参考。     

广西元宝山中山针阔叶混交林的群落特征

采用样地调查法对广西元宝山中山针阔叶混交林的种类组成、分布区类型、生活型谱和叶片特征等进行了调查和分析.结果表明:该针阔叶混交林种类组成较丰富、物种多样性程度较高,共有维管植物96科201属379种,其中,蕨类植物19科26属33种,种子植物77科175属346种.在种子植物中,单种科和少种科(2～5种)所占比例较大(41.6%和32.5%),蔷薇科(Rosaceae)、杜鹃花科(Ericaceae)、山茶科(Theaceae)、樟科(Lauraceae)、壳斗科(Fagaceae)、冬青科(Aquifoliaceae)、禾本科(Gramineae)、山矾科(Symplocaceae)和百合科(Liliaceae)种类较多,并含有较多起源古老的残遗植物.该针阔叶混交林的种子植物属共有12个分布区类型, 其中, 中国特有分布属 4属,分别是长苞铁杉属(Nothotsuga Hu ex Page)、棱果花属(Barthea Hook. f. )、匙叶草属(Latouchea Franch. )和马铃苣苔属(Oreocharis Benth. );热带分布型属和温带分布型属占绝对优势(53.6%和44.0%),且热带成分所占比例略高于温带成分,表明该群落植物区系表现为明显的亚热带山地性质.群落中以高位芽植物为主(60.4%),藤本植物和地面芽植物也占有较高比例(12.1%和11.1%).群落的叶级以小型叶为主(55.4%),叶片特征以单叶(85.8%)、革质叶(52.6%)和全缘叶(61.2%)为主.此外,在群落的乔木层上层,针叶树种、落叶阔叶树种和常绿阔叶树种的比例分别为23.1%、34.6%和42.3%,表明该群落的中山针阔叶混交林特点十分明显.     

四川卧龙地区珙桐群落的结构与更新研究

 在野外调查基础上,分析了四川卧龙地区珙桐群落的物种构成与生物多样性、群落外貌、结构和珙桐的更新动态。结果表明：1)珙桐群落植物区系丰富、古老、特有性强：2)落叶大、中高位芽和常绿中、小高位芽植物共同构成群落外貌;群落垂直结构复杂,草本层发育;3)在群落演替的前、中期,珙桐种群结构由扩展型变为稳定型;4)珙桐的有性繁殖更新机率随其在群落中重要值的上升而下降。     

Tertiary relic deciduous forests on a humid subtropical mountain, Mt. Emei, Sichuan, China

The floristic characteristics, age structure and survival modes of Tertiary-relic deciduous forests were analyzed at 1600 m on Mt. Emei (3099 m), Sichuan, China. Three plots were selected to represent typical topographies: Plot 1 at 1620 m on a scree slope, Plot 2 at 1640 m on a slope with moderately rocky soils, and Plot 3 at 1616 m on a gentle slope with less rocky soils. At Plot 1, on the scree slope, the forest was rich in species and dominated by Tertiary remnants and other deciduous trees (Davidia involucrata, Styrax hemsleyana, Cercidiphyllum japonicum var.sinense, Pterocarya hupehensis, Prunus brachypoda, Prunus padus, Tetracentron sinense andStaphylea holocarpa). The relic deciduous tree taxaDavidia, Cercidiphyllum, Tetracentron andEuptelea occupied the unstable concave slopes, where evergreen broad-leaved trees (Castanopsis platycantha andMachilus pingii) were rarely able to survive. On the relatively stable convex slopes of this plot, evergreen trees with small diameter mainly appeared in the subcanopy and shrub layers.Davidia involucrata was the dominant species in this forest. On the slope with moderately rocky soils (Plot 2), the forest was co-dominated by relicDavidia and other deciduous (Styrax andPterocarya), and evergreen trees (Castanopsis andMachilus). On the gentle slope with less rocky soils (Plot 3),Davidia trees were found only in the subcanopy and shrub layers, and the forest was dominated byMachilus, Castanopsis, Styrax andPrunus trees. Regeneration ofDavidia occurs mainly on the scree slope where landslides are most common. The age structure of theDavidia stands indicates that this species is able to survive on the unstable scree habitat due to its strong sprouting ability. The Tertiary-relic deciduous forest on the scree slope is seen to be a topographic climax forest.     

湖南大围山杜鹃灌丛的群落组成及结构特征

灌丛是陆地生态系统中最重要的自然植被类型之一, 在植被演替、生物多样性保护和维持生态平衡等方面具有重要作用。本文基于2012年的样地资料, 对湖南大围山杜鹃(Rhododendron simsii)灌丛的物种组成和群落结构进行了分析。结果表明: 群落内共有维管束植物58种, 隶属于36科50属, 其中木本植物19种, 草本植物39种, 缺乏木质藤本; 区系以温带性质为主, 兼受热带亚热带区系的强烈影响; 群落外貌矮平, 灌木层个体集中在1-2 m高度级; 植被分类上, 该群落归属于山地中生落叶阔叶灌丛, 隶属于温性落叶阔叶灌丛群系组; 生活型以地面芽和高位芽植物为主, 反映了亚热带中山山顶温凉湿润的气候特点; 群落各层次优势种明显, 具有较高的稳定性和均匀性; 高度级和基径级分析表明群落内中等大小个体具有保守的生活史策略, 优势种杜鹃为远期衰退种群。综合分析结果表明, 该杜鹃灌丛尚处于群落演替的中期或前中期, 最终将演替为亚热带中山常绿落叶阔叶混交林或常绿阔叶林。     

Zonal transition of evergreen,deciduous, and coniferous forests along the altitudinal gradient on a humid subtropical mountain,Mt. Emei,Sichuan, China

Altitudinal zonation of evergreen, deciduous and coniferous forests on Mt. Emei (3099 m asl, 29°34.5' N, 103°21.5' E), Sichuan, China was studied to understand the transition of vegetation zonation from tropical to temperate mountains in humid Asia. On the basis of quantitative data on floristic composition and community structure sampled at ten plots selected in different altitudes on the eastern slope of the mountain, forest zonation and the inter-relationships among different life-forms of trees in each zonal forest community were studied quantitatively. Three forest zones were identified physiognomically along the altitudinal gradient, viz. (i) the evergreen broad-leaved forest zone (660–1500 m asl), (ii) the mixed forest zone (1500–2500 m asl), and (iii) the coniferous forest zone (2500–3099 m asl). Great compositional changes were observed along elevation, and the zonal forest communities were characterized by their dominants and floristic composition. Maximum tree height decreased from 33 m at lower middle altitude (965 m asl) to 13 m near the summit (2945 m asl). There was no apparent deciduous forest zone along the altitudinal gradient, but true mixed forests of three life-forms (evergreen, deciduous, and coniferous) were formed around 2000–2500 m asl. Patches of deciduous forest were found in a lower part of the mixed forest zone, particularly on scree slopes, between 1450 m and 1900 m asl. These patches were dominated by the Tertiary relic deciduous trees, such as Davidia involucrata, Tetracentron sinense, and Cercidiphyllum japonicum var. sinense. High species diversity in the mixed forest zone resulted from the overlapping of different life-forms at middle altitudes, which is partly due to wider variety of temperature-altitude correlations. A comparison of the altitudinal zonation with the other east Asian mountain vegetation clarified that Mt. Emei is located exactly at the ecotone between tropical and temperate zonation types in eastern Asia.     

土壤氮素与光照对盆栽珙桐幼苗光合参数的影响

珙桐是我国特有珍稀保护物种,在植物系统发育和地史变迁研究上有很高的学术地位,国内外学者进行了大量的研究。以濒危植物珙桐(Davidia involucrate)一年生幼苗为试验材料,通过控制土壤氮素含量与光照的方法,研究了不同土壤氮素含量(0mg、200mg、400mg、600mg、800mg)及是否遮光对珙桐幼苗生长和光合参数的影响,探讨土壤氮素及光照对珙桐幼苗生长的影响。结果表明:1)高氮素水平可以减缓在非适生环境下生长的珙桐幼苗光合速率的降低;2)适宜的直射光照可能对珙桐等喜阴植物的幼苗的生长是有利的;3)氮素对由遮光引起的光合参数的降低有补偿作用,但仍无法完全抵消由于遮光所引起的净光合速率的降低。     

Structures and topographical pattern of the tree layer of Fagus engleriana-Cyclobalanopsis oxyodon community in Shennongjia area, Hubei Province, China

Shennongjia represents an area of considerable plant biodiversity, not only for China but for the whole world. The numerous species are distributed along an altitude gradient. The genus Fagus, commonly known as Beeches, constitutes one of the dominant woody species of the humid temperate forests in China. This paper deals with the community structure of a mixed, broadleaved deciduous-evergreen beech forest dominated by the Fagus engleriana and Cyclobalanopsis oxyodon, which occurs along an altitude gradient range in this area. The community consists of 46 woody species, belonging to 22 families and 27 genera. The tree layer can be divided into three sub-strata. The upper layer is composed of deciduous trees, 80.7% of which is E engleriana. The second and third layers are dominated by the evergreen species, such as C. oxyodon and the Rhododendron hypoglaucum. These species increase from 55.9% in the second layer to 80.5% in the third, and regeneration at that rate allows us to assume that the stability of the community may be guaranteed. The micro-site heterogeneity plays an important role in maintaining species diversity in plant communities. In this research, a terrain surface of 0.96 hm<'2> was simulated using the digital elevation model (DEM) in order to analyze the influence of the topography on plant community structures on a small scale. The slope relief aspect obtained with the DEM showed an accentuated heterogeneity. Semivariance analysis was used to measure the heterogeneity scale. The range and nugget variance of the semivariograms for slope were 285.8 and 280.5, respectively; for aspect, were 21.8 and 498, respectively. The elevated value of the nugget variance suggested that even on a small scale, the topographic variations influenced the species distribution. Twenty-four species were selected to estimate the correlation coefficient between the slope, aspect, and orientation. Then based on the correlation results using the Square Euclidean Distance cluster analysis, the 24 species were divided into four groups.     

Habitat factors affecting site occupancy and relative abundance of four-horned antelope

The four-horned antelope is endemic to the Indian sub-continent. It was formerly distributed widely in deciduous forests throughout its range, but the current distributional patterns of this low-density species are largely unknown and conservation efforts are hampered by the lack of information on species–habitat relationships. We investigated the habitat factors influencing four-horned antelope occurrence and abundance in Bandipur National Park, an important four-horned antelope conservation site in India. Detection/non-detection data, collected under a systematic sampling framework, were used to test a priori hypotheses incorporating covariates believed to influence occurrence and abundance. The best fitting models for four-horned antelope occurrence and relative abundance reveal that the tree-savanna deciduous habitat sub-type, characterized by relatively open habitats with a lower tree density and a high degree of deciduousness, is most preferred by the species. Four-horned antelope conservation efforts in Bandipur National Park and other reserves should be focused on areas typified by tree-savanna habitats. Four-horned antelope occurrence was negatively related to the alien weed Lantana camara . The prolific spread of this weed in Indian deciduous forests is a likely threat.     

罗霄山脉种子植物区系的特有现象与残遗现象

罗霄山脉种子植物区系非常丰富, 是连接华东、华南、华中植物区系的重要通道, 区系组成具有明显的古老性和过渡性特征。本文针对该区域种子植物的特有现象和残遗现象, 分析了其组成特点及形成原因。结果表明: (1)罗霄山脉共有中国特有科3科, 特有属55属, 特有种1,624种, 罗霄山脉区域特有种43种7变种; 特有属中以古特有属为主, 并以温带成分占优势(达55.91%), 体现出明显的古老性和孑遗性。(2)罗霄山脉共有孑遗属165属, 以热带亚洲分布、东亚-北美间断分布、东亚特有及中国特有成分为主, 包括木本属132属。(3)受中新世气候波动以及第四纪冰期的影响, 许多北方热带植物群的常绿成分、北极-第三纪的落叶成分, 在罗霄山脉得以保存下来成为古特有和孑遗成分。特有现象、残遗现象的分析结果表明罗霄山脉是一个重要的生物避难所, 其对中国东部植物区系的保存和重新扩散具有重要意义。