Diversity and structural composition of species in dipterocarp forests:a study from Fasiakhali Wildlife Sanctuary, Bangladesh

Fasiakhali Wildlife Sanctuary is a protected area composed of tropical remnant rainforest that harbor substantial number of large,old Garjan（Dipterocarpus spp.）trees.The present study assessed composition,structure and diversity of the species in this protected area.A total of 32 trees species were recorded with DBH ≥ 11 cm belonging to 24 genera and 19 families.The forest is low in plant diversity as represented by Shannon–Wiener diversity and Simpson Dominance indices.Dipterocarpus turbinatus was the most dominant species with maximum relative density,frequency,dominance,and importance value index.Syzygium firmum and Tectona grandis followed in terms of dominance.The structural composition indicated higher number of individuals in the medium growth classes（41 to 〈 511 cm DBH and 16–20 m height ranges）,whereas D.turbinatus was the only species that dominated most of the growth classes.Poor stem density in lower growth classes indicated meager recruitment of regeneration which may be due to lower annual precipitation,increased grazing and encroachments.This study will help to understand the patterns of tree species composition and diversity in the remnant dipterocarp forests of Bangladesh.It will also contribute to identifying threatened plants to undertake D.turbinatus based conservation and sustainable management of the Fasiakhali Wildlife Sanctuary.

Relationship between diversity of forest plant species and environmental gradient in eastern mountainous area of Heilongjiang Province, China

Twenty-three secondary forest communities with different structure were selected in Mao＇er Mountain National Park of Heilongjiang Province, China to study the relationship between diversity of forest plant species and environmental gradient. The forest plant species diversity was analyzed by the diversity index, and the environmental factors was quantified by the method of Whittaker＇s quantification of environmental gradient. Meanwhile, β-diversity indexes of communities were calculated with similar measurements. The results showed that the Shannon-wiener diversity index of forest plant species increased with the increase of the environmental gradient, and the β-diversity indexes of communities showed a liner increase along with the change of environmental gradient.

Changes in tree species diversity and dominance across a disturbance gradient in Nepalese Sal (Shorea robusta Gaertn. f.) forests

Disturbance is often touted as a management tool, as moderate disturbance is believed to enhance diversity; thus an understanding of frequent and fluctuating disturbance regimes in forests and their effects on stand structure, dominance and diversity is very crucial. Here, the effects of different disturbance regimes, along a gradient, on diversity and dominance of five Shorea robusta Gaertn. f.-dominated forests were investigated in 25 one-ha plots in Nepal. A total of 67 tree species were recorded; of which 41 species were encountered in least disturbed and 10 species in beavily disturbed forest. Significant variations among forests were observed for all measures of alpha diversity. Alpha diversity measures declined linearly along a disturbance gradient while dominance increased linearly. Relative basal area of S. robusta increased as the level of disturbance increased, which in turn produced more than two-fold higher important value index in heavily disturbed forest than the least disturbed forest. All alpha diversity measures declined in an order of three with increasing relative basal area of S. robusta. The similarity in species composition between each pair of disturbed forests was generally low （Jaccard＇s similarity index 〈 57%）, suggesting a higher Beta diversity, It can be concluded that diversity of Sal forests declines with increasing magnitude of disturbance, which in turn favors a higher domi- nance of S. robusta. Controlling the population of the dominant species, mainly S. robusta, is recommended to enhance diversity and to achieve multiple-use forest management objectives.

The Rich-Gini-Simpson quadratic index of biodiversity

The Gini-Simpson quadratic index is a classic measure of diversity, widely used by ecologists. As shown recently, however, this index is not suitable for the measurement of beta diversity when the number of species is very large. The objective of this paper is to introduce the Rich- Gini-Simpson quadratic index which preserves all the qualities of the classic Gini-Simpson index but behaves very well even when the number of species is very large. The additive partitioning of species diversity using the Rich-Gini- Simpson quadratic index and an application from island biogeography are analyzed.

Isolation and species diversity of arbuscular mycorrhizal fungi in the rhizosphere of Puccinellia tenuiflora of Songnen saline-alkaline grassland,China

Salinization has led to the deterioration of the ecological environment,affected the growth of plants,and hindered the development of agriculture and forestry.Arbuscular mycorrhizal(AM)fungi,as important soil microorganisms,play significant physiological and ecological roles in promoting plant nutrient absorption and improving soil structure.Puccinellia tenuiflora(Turcz.)Scribn.et Merr.in Songnen saline-alkaline grassland was selected as the research object to observe AM fungal colonization of the roots and explore the species and diversity of AM fungi in symbiotic association with P.tenuiflora.This study showed that AM fungi colonized in P.tenuiflora roots and formed a typical Arum-type mycorrhizal structure.A significant correlation was observed between vesicular abundance and the colonization intensity of mycorrhiza.Isolation and identification revealed 40 species of AM fungi in the rhizosphere of P.tenuiflora,belonging to 14 genera,of which two species could not be identified.The richness of the genus Glomus was the highest,accounting for 30%of the total species.Funneliformis mosseae and Rhizophagus intraradices were isolated from all the samples and were the species with the widest distribution in the rhizosphere of P.tenuiflora.Correlation analysis showed that pH only had a significant impact on the distribution of a few species,such as Glomus pustulatum,Diversispora spurca,Glomus aggregatum,Rhizophagus clarum,and Acaulospora foveata.The present study provides a theoretical basis for further exploring the resources of AM fungi in saline-alkaline soil.

Effect of exclosure ages on woody plant structure,diversity and regeneration potential in the western Tigray region of Ethiopia

Exclosure is a method of rehabilitating degraded lands by protecting them from the interference of animals and from human encroachment, and is used to regenerate native vegetation as a way to reduce soil erosion, increase rain water infiltration and provide fodder and woody biomass in degraded grazing lands. Therefore, we studied woody plant structure, diversity and regeneration potentials in 5-and 10-year grazing exclosures in comparison with open grazed sites in a semi-arid environment. Data on species diversity, abundance, structure, basal area, frequency, density, and regeneration status were collected from 270 sample plots. Forty-one woody species representing 20 families were identified, with 18, 28 and 38 species found in open grazed areas, and in 5-and 10-year grazing exclosures, respectively. The 10-year grazing exclosures had a higher(P <0.05) species richness and plant densities compared to the 5-year grazing exclosures and the open grazed areas. The population structure and regeneration status of woody species in both grazing exclosures showed an inverted J-shape, indicating a healthy regeneration status, whereas hampered regeneration was observed in open grazed areas. The establishment of grazing exclosures had positive effects in restoring woody plant diversity and improving vegetation structure and regeneration potentials of degraded grazing lands.

Global comparisons of beta diversity among mammals,birds,reptiles,and amphibians across spatial scales and taxonomic ranks

Beta diversity is the change in species composition among areas in a geographic region. The proportion of species shared between two areas often decreases when the distance separating them increases, leading to an increase in beta diversity. This study compares beta diversity among four classes of terrestrial vertebrates （mammals, birds, reptiles, and amphibians） at both regional （biogeographic realm） and global extents, using the same sets of faunal sample units for all four groups in each comparison. Beta diversity is lower for the two endothermic taxa （birds and mammals） than for the two ectothermic taxa （reptiles and amphibians） in all six biogeographic realms examined. When the four taxa in the six biogeographic realms are combined, beta diversity at the species rank is higher than that of the genus rank by a factor of 1.24, and is higher than that of the family rank by a factor of 1.85. The ratio of beta diversity at the genus rank to that at the family rank is 1.50. Beta diversity is slightly higher for ecoregions of 5000-99,999 km^2 than for ecoregions of 100,000-5,000,000 km^2.

Evaluation of Broadleaf Tree Diversity at the Basin Scale—In Case of Artificial <i>Chamaecyparis obtusa</i>Forests

In recent years, the various functions required of forests, especially the conservation of biodiversity, have been attracting increasing attention in Japan and worldwide. In Japan, 67% of national land is covered by forest, 41% of which is artificial forest (i.e., plantations). Therefore, forest biodiversity conservation efforts should also target artificial forests. In this paper, we seek to promote sustainable forest management that considers biodiversity conservation by examining indices that can be used by forest managers to evaluate the diversity of broadleaf trees. The result was that evaluation of broadleaf tree diversity in artificial forests at a basin scale was possible by combining several types of indicators.

Can picnic influence floral diversity and vitality of trees in Bhawal National Park of Bangladesh?

We examined the impact of picnic activities on forest diversity, structure, regeneration and vitality of tree species in the Bhawal National Park of Bangladesh. The study area was classified as a non-used, occasionally used and frequently used area on the basis of the intensity of the picnic activities. A total of 43 plant species were enumerated in the whole study area. The highest plant species richness （41 species） was observed in the non-used area whereas the lowest species richness （11 species） in the frequently used area. The diversity index decreased with the increase of picnic intensity whereas the concentration of dominance increased. Density of all plant groups except mature trees, and the basal area of the mature trees showed a declining trend from the non-used to frequently used area. The frequently used area exhibited very poor regeneration. Tree vitality decreased with the increase of picnic intensity. The relevance of our study as a basis for further research to determine the impact of tourism on biodiversity in Bangladesh is discussed.

Bayesian Estimation of Shrubs Diversity in Rangelands under Two Management Systems in Northern Syria

The diversity of shrubs in rangelands of northern Syria is affected by the grazing management systems restricted by the increase in human and livestock populations. To describe and estimate diversity and compare the rangeland grazing management treatments, two popular indices for diversity, the Shannon index and the Simpson index, were studied for the four combinations of two sites, Hammam and Obeisan, and two grazing methods, Closed and Open, using frequentist and Bayesian approaches. We simulated the a priori and a-posteriori distributions of the Shannon and Simpson diversity indices, where from a range of values for a constant in the a priori distribution the best value normalizing the distribution of the diversity indices was chosen. The Bayesian diversity estimates were higher than their frequentist counterparts and had lower standard errors. The grazing methods at each site and sites under each grazing method delivered significant diversity of shrub species. The Bayesian estimates resulted in lower p-values than the frequentist approach for two cases reflecting in Bayesian method’s higher power. Bayesian approach is recommended as it has a wider framework for inference on diversity studies.

Assessment of Tree Diversity and Abundance in Rashad Natural Reserved Forest, South Kordofan, Sudan

This study aims to estimate the tree diversity status of Rashad Forest Reserves in the Rashad locality of the South Kordofan State of Sudan. For data collection, eight sample plots (20 × 20 m) were taken randomly, and parameters were determined: trees species diversity, composition, relative density, dominance, important value index, and species richness in the Rashad forest reserve. The results show that a total of 237 and 56 tree species, including 22 families, have been identified in the study area. Fabaceae family and species numbers have the highest number of 13 species in 8 genera, followed by Combretaceae with 8 species belonging to 3 different genera, Malvaceae with 5 species belonging to 4 different genera, Apocynaceae with 3 species belonging to 3 different genera. The Arecaceae, Burseraceae, Capparaceae, Euphorbiaceae, Meliaceae, and Rubiaceae families each had two species, and all the other 11 families had one species each. Among the 56 different tree species found within the reserve. The results also indicated that Tamarindus indica L. and Ziziphus spina-christi (L.) Desf. had the highest relative density and dominance of 4.64% and 11% respectively. Adansonia digitata L., Grewia villosa Willd, Vepris nobilis (Delile) Mziray had density and dominance of 4.80% and 9%. Followed by Anogeissus leiocarpa (DC.) Guill. & Perr, Adansonia digitata L., Catunaregam nilotica (Stapf) Tirveng. (Syn: Xeromphis nilotica (Stapf) Keay, Vangueria madagascariensis J. F. Gmel. with 3.38% and 8%, respectively. Eleven species recorded the least relative dominance of 0.42%. Shannon-Weiner diversity index (H’) value stood at 3.82. And as diversity indices varied with location depending on the species available within an ecological zone, Rashad forest reserve is blessed with a moderate diversity index.

Characterization of sugar diversity in floral and extra-floral nectar from the Coastal Coral Tree(Erythrina caffra Thunb.)in Southern California

The Coastal Coral Tree (Erythrina caffra Thunb.) produces floral nectar (FN) that serves to attract pollinating insects, but also secretes nectar from extra-floral (EFN) glands that serves to attract predatory insects, such as ants. While studies on myrmecophytes (i.e. specialized plants that attract and interact with ants) have primarily focused on interspecific evaluations of EFN chemistry, the Coastal Coral tree offers an opportunity to contrast intraspecific nectar chemistry with differing evolutionary and ecological functions. We hypothesized that the richness of (molecular) sugar species, relative concentrations, and diversity of sugars in FN and foliar EFN would diverge due to differences in the ecological role of the two types of nectar. High performance liquid chromatography with refractive index detection was used to identify the richness of sugar species (based on retention time), measure the relative concentrations, and evaluate the diversity of sugars in FN and foliar EFN secretions. We detected sugar species unique to each gland type and reported significant differences in the relative concentration of one sugar species common to both gland types. While the mean diversity index of sugars was similar for both gland types, the diversity of foliar EFN sugars was significantly more variable than that of FN sugars. The composition of FN showed little variation, and was reflective of its fundamental role in plant reproduction. Foliar EFN, however, demonstrated the variability expected of a context-dependent myrmecophyte that interacts with a facultative ant species assemblage across a mosaic of abiotic and biotic conditions.

大别山南坡森林植物群落物种多样性及其与海拔因子的关系

大别山地区植物资源丰富,区系组成复杂且起源古老,为连接华东、华北和华中三大植物区系的纽带,也是我国重要的生物多样性保护和水源涵养生态功能区。采用样方法,在大别山南坡的多枝尖、庵基坪和麒麟沟3个地区,沿着不同海拔高度选取了具有代表性的森林植物群落进行研究,从不同植物群落类型和层次的物种多样性、均匀度和丰富度及其与海拔因子的关系等方面,对大别山南坡的森林植物群落物种多样性进行综合分析。结果表明:1.共记录有植物108科270属449种,划分为20个森林植物群落类型;2.森林植物群落各层次物种丰富度表现为草本>乔木>灌木;Shannon-Wiener多样性指数和Simpson多样性指数呈现出乔木>灌木>草本;Pielou均匀度指数变化较为复杂;3.森林植物群落各层次的物种丰富度随海拔升高而下降;Shannon-Wiener指数和Simpson指数也表现为随着海拔升高而下降,但草本层在1400m之后有上升的趋势。Pielou指数在乔木层中表现为随着海拔的升高而下降,在草本层中表现为先下降后出现上升,在灌木层中则随着海拔的升高而上升,但其波动更为剧烈。本研究对大别山南坡森林植被大范围的采样观测研究,能够全面的展现大别山南坡森林植物的种类分布、空间组成等整体概况及其与海拔因子的关系,能为以后大别山南坡生物多样性的保护提供较为全面真实的数据,从而为大别山地区生物多样性的保护和可持续利用提供理论依据和实践意义。

山西省亚高山草甸群落组成及其多样性研究

【目的】以山西省从南到北分布的6个亚高山草甸为研究对象,探讨亚高山草甸的群落物种多样性和空间分布格局。【方法】采用有限样方内生物多样性的测定方法,测定了从南到北分布的6个亚高山草甸的物种组成和多样性指数,并比较了各草甸之间的群落相似性。【结果】6个亚高山草甸上共有172种植物,菊科、禾本科、蔷薇科、豆科分布较为广泛。各草甸物种多样性指数存在显著差异(P<0.05),其中大同市灵丘县亚高山草甸的群落物种多样性和丰富度指数最高,太原市娄烦县亚高山草甸的均匀度最高。从物种组成的群落相似性结果来看,吕梁市离石区亚高山草甸与大同市灵丘县亚高山草甸的物种组成相似性最高,忻州市宁武县亚高山草甸和大同市广灵县亚高山草甸的物种组成相似度最低。【结论】随着海拔的升高,亚高山草甸的多样性指数呈现随之降低的趋势。

甘肃连城国家级自然保护区蝶类多样性及种-多度分布

为明确甘肃连城国家级自然保护区蝶类多样性及种-多度分布情况,采用样线法,共选定8条样线进行蝴蝶标本采集,并对保护区内不同生境蝴蝶的多样性及种-多度分布进行分析。结果显示:共采集标本998号,隶属7科60属102种。保护区内优势科主要为粉蝶科(Pieridae)与蛱蝶科(Nymphalidae);优势种主要集中在粉蝶科,包括箭纹绢粉蝶(Aporia procris)、绢粉蝶(Aporia crataegi)、秦岭绢粉蝶(Aporia tsinglingica)等。区系分析表明,保护区内古北种占34.31%,东洋种占19.61%,广布种占46.08%,其中广布种占主导地位。各样线的多样性指数表明,样线Ⅴ(森林-灌丛-草甸)的科级多样性指数、优势度指数、物种丰富度指数及个体数均为最高,样线Ⅲ(森林)的属级多样性指数最高,样线Ⅱ(森林-灌丛)均匀度指数、种级多样性指数最高。相似性结果表明:样线Ⅲ(森林)和样线Ⅷ(森林)的相似性系数最高(0.509 1),呈中等相似;样线Ⅱ(森林-灌丛)和样线Ⅳ(森林-灌丛),样线Ⅲ(森林)和样线Ⅳ(森林-灌丛)相似性系数分别为0.230 8、0.229 7,位于极不相似区间,其余样线之间皆处于中等不相似。种-多度分析显示,保护区蝶类总体呈对数级正态分布,而样线Ⅴ与样线Ⅲ与Preston对数正态模型的吻合度较高,且样线Ⅴ的拟合效果最佳。表明样线Ⅴ(森林-灌丛-草甸)的生境条件优于其他样线,蝶类对其具有较高适应性。总体来看,保护区内生境良好,结构稳定,有利于蝴蝶群落生存。但不同生境及人为干扰等因素是影响蝴蝶多样性的主要原因,应对保护区内生境加强保护,减少对环境的破坏,从而使得保护区内生物多样性保持稳定水平。

西洞庭湖洲滩植物物种与功能多样性空间分布特征及其相关性

洞庭湖是长江中下游重要的通江湖泊,具有调蓄洪水和维护周边湿地生态系统及生物多样性等生态功能。研究植物群落物种多样性与功能多样性在异质环境条件下的特征及其相关关系,对认识植物群落分布规律、保护修复生态系统结构和功能具有重要意义。以西洞庭湖沅江和澧水水流方向上的洲滩植物群落为研究对象,采集优势种并测定其根和叶的碳氮磷含量、叶面积和根长等8个功能性状来研究群落间物种多样性差异、水流方向上洲滩群落功能多样性差异、物种多样性和群落功能多样性的关系及多样性指数间的相关性。研究结果表明:(1)沿水流方向不同位置植物群落物种多样性有显著差异。其中,沅江和澧水的水流方向上入湖口物种丰富度均较低;在所有调查区域中,沅江中游洲滩植物群落物种丰富度、香农指数均较高,出湖口的物种多样性最低。(2)澧水上游洲滩植物群落的碳氮磷含量的群落加权平均值(community weighted-mean,CWM)和Rao二次熵指数较高;澧水中游植物群落所有性状的CWM值和Rao二次熵指数最低;沅江上游植物群落具有较高的叶性状值,优势种中一年生草本植物的快速生长策略可能贡献较高的叶性状值。(3)西洞庭湖洲滩植物群落物种多样性与CWM值具有显著相关性,根碳含量的CWM值与物种丰富度、香农指数呈负相关;水流方向上不同位置植物群落物种多样性与Rao二次熵指数没有相关性。研究结果说明,沅、澧两水及沿水流方向不同调查区域的水文地貌特征差异对洲滩湿地植物群落物种和功能多样性都有影响,但拥有更高物种多样性(优势种组成、丰富度等)的植物群落适应能力并不一定更强。此外,沿水流方向,湖泊洲滩植物群落的物种与功能多样性趋异。因此,在西洞庭湖洲滩植物群落的保护和修复工作中需要综合考虑更多因素(如土壤、地形等),以便更全面地了解其生态系统的复杂性和特殊性。

大庆市蝶类多样性及其影响因素

为明确大庆市蝶类多样性及其影响因素,2016-2019年利用样线法对大庆市不同生境类型中的蝴蝶开展了调查研究。共观测到蝴蝶5780只,隶属6科29属36种。灰蝶科的个体数最多,蛱蝶科的物种数最多,是当地的优势类群;凤蝶科仅1种,是当地的稀有类群。优势种7个,常见种5个,少见种4个,稀有种20个。不同的生境蝶类群落种类与数量存在一定的差异,人为干扰小、植物群落结构最为复杂的新华草原蝶类的属数和种数最多,而人为干扰较强、植物群落单一的大庆龙凤湿地自然保护区最少;新华草原的蝶类多样性指数最高,大庆龙凤湿地自然保护区最低;新华草原的丰富度指数最高,乘风湖岸边最低。蝶类物种数、个体数、多样性指数及丰富度指数月度变化基本一致,且与月均温显著正相关(P<0.05),而与月降水量无相关性。综上,蝶类多样性与植被类型、月均温有明显的相关性。而相同气象条件下,植被类型是影响蝶类分布的重要因素。为了保护与丰富蝶类资源,建议植被单一的区域,进行适度的植被异质化建设。

淳安县野生脊椎动物物种调查编目研究——爬行纲动物

在淳安县生物多样性最富集的磨心尖、千岛湖、淳安湿地等区域开展野生脊椎动物实地调查的基础上,对该县爬行纲野生脊椎动物物种调查编目进行研究。结果表明:淳安县爬行纲野生脊椎动物调查编目,共收录物种42种,隶属于2目10科34属。其中,国家一级保护1种,浙江省重点保护9种,IUCN红色名录极危(CR)3种,中国脊椎动物红色名录极危(CR)2种、濒危(EN)7种,CITES附录Ⅰ物种2种、附录Ⅱ物种3种、附录Ⅲ物种1种,中国特有种8种。分布型以南中国型(S)为主体,有26种,占爬行纲物种总数的61.90%。地理区系以东洋种为绝对优势,有39种,占爬行纲物种总数的92.86%。物种多样性G-F指数计算,D G、D F和G-F指数分别为3.37、6.79和0.50,与邻近的江西省的5个动物地理省比较,淳安县爬行动物G-F指数高于江西4个动物地理省,低于江西1个动物地理省。

河北太行山五个自然景观的昆虫物种多样性比较与区系分析

本文基于多年对河北太行山区自北向南5个自然景观(小五台山、五岳寨、不老青山、老爷山、太行山南段)的昆虫物种考察和资料总结,获得昆虫5 945种,隶属4纲32目353科3 046属,对其种类组成和多样性组成进行了横向分析比较,得到如下初步结果:鳞翅目和鞘翅目是构成河北太行山区昆虫物种多样性的最主要类群,两者的物种总数高达3 834种,占昆虫总种数的64.49%;属级构成中日界(3 046属,100%)>古北界(2 511属,82.40%)>东洋界(1 830属,60.07%),凸显该地区的中日界性质(100%),同时与古北界有密切的联系,与东洋界也有较强的关联;在中国动物地理区中,华北区(3 046属,100%)>华中区(2 556属,83.91%)>蒙新区(2 404属,78.92%),华北区成分最为显著(100%),与华中区与蒙新区的联系较为紧密,其次为西南区、东北区、青藏区,而与华南区的联系最弱。对比分析了5个自然景观的鞘翅目物种多样性G-F指数,以小五台山的最高,不老青山最低,整体呈现由北向南随维度不断降低,其物种多样性不断增加的趋势;五岳寨国家森林公园与不老青山森林景区相似性较高(0.53),为中度相似,老爷山与太行山南段、不老青山与老爷山、五岳寨与老爷山为轻度相似;而小五台与五岳寨、小五台山与不老青山、小五台山与老爷山、小五台山与太行山南段为极不相似的关系,讨论了多个相关问题。

城市公园物种多样性保护与生态发展研究——以乌兰察布市公园为例

为了分析西北地区城市公园植物配植组成的多样性,采用指标分析方法,对乌兰察布市6个公园进行调查研究。结果表明:6个公园中除白泉山公园外,Margalef指数均为乔木层>灌木层,榆树湾公园的物种丰富度最低;乔木层和灌木层的生态优势度指数普遍偏高,其中霸王河公园乔灌木层的Simpson指数相差最大;Shannon-Wiener指数在某种程度上变化趋于一致,乔灌木层的不确定性差别都较大;平均密度的分析表明公园内的植物种植密度普遍偏大。指出了乌兰察布市公园建设存在植物选择面小、设计理念不合理、植物配植不丰富等问题。基于此,提出了在该地区公园的建设及后期的景观提升工作中,应采取适地适树的举措,保持和恢复植物多样性,从而发挥公园保障城市景观,促进城市生态健康可持续发展的重要作用。