TWINSPAN Classification Research Articles

Drivers of the Distribution of Ecological Species Groups in Temperate Deciduous Managed Forests in the Western Carpathian Mountains

Managed broadleaf deciduous forests are an important type of forest vegetation in Central Europe, also in the Western Carpathians. These forests are both economically and environmentally valuable. However, little is known about ecological species groups and the inter-specific associations of dominant species in temperate deciduous managed forests in Central Europe. Since the forest stands are in a managed landscape, they are not consistent with the traditionally recognized and used vegetation associations in the Western Carpathians. For these reasons our research contributes to understanding the consequences of broadleaf deciduous forest management. The aim of this research was the determination of ecological species groups and an investigation into the main environmental drivers, in order to explain the distribution of ecological species groups. The numerical TWINSPAN classification was selected to distribute 146 relevés to the five ecological species groups. Of these, 77 relevés were divided into two groups with Fagus sylvatica dominant, while 63 relevés were Quercus petraea dominant. Carpinus betulus, Tilia cordata and Fraxinus excelsior were dominant in 19 relevés. Constrained Analysis of Principal Components was used to explain the vegetation–environment relationship on three transects in the Male Karpaty Mountains. Altitude, pH, Ca, C, K and Mg were selected as the significant environmental drivers responsible for a large part of the species group variability (31.8%). The main requirement for sustainable forest management is knowledge of the vegetation–environment relationship and this research was focused on gaining such understanding. This knowledge can be used as a decision support tool for sustainable management in managed deciduous forests.

On the Ecology of Weeds in the Orchards habitat During Summer Season in Nile Delta, Egypt

The present study aims to investigate the ecology of weed communities associated with some orchards habitat using the variations in environmental factors to determine the distribution and abundance of the recognized weed communities in the study areas. The sampled stands were distributed in four Governorates. Field visits were started from January 2014 to September 2015, 45 stands were selected for sampling the vegetation types during summer season. The application of TWINSPAN classification based on the importance values of 49 plant species recorded in selected 45 sampled stands representing the summer orchards sites in the study areas led to the recognition of four vegetation groups (Euphorbia heterophylla, Commelina benghalensis, Cynanchum acutum and Xanthium strumarium were the dominate plants). In summer season, the application of DCA technique proved that, the plant communities recognized by TWINSPAN classification were markedly distinguishable and having clear pattern of segregation on the ordination plane. The application of CCA technique was used to determine the most effective soil variables controlling the abundance and distribution of weed communities associated during summer season.

Numerical classification and ordination of Esenli (Giresun) forest vegetation

The forest vegetation of Esenli Forest Planning Unit was investigated between 2015 and 2018 from the phytosociological point of view. The study area is situated in the Euxine province of Euro-Siberian Region. Phytosociological studies were carried out in accordance with the classical Braun-Blanquet methodology, and 131 releves were collected during the field survey. The releves were classified using the Modified TWINSPAN classification, and general distribution patterns of vegetation were analysed using indirect ordination analysis (Principal Component Analysis) with the R-Project available in the JUICE program. In addition to topographic factors, ecological factors were assessed using the mean Ellenberg Indicator Values to observe the ecological relationships among communities. Four new plant associations (Cirsio trachylepidis-Pinetum sylvestris, Angelico sylvestri-Alnetum barbatae, Circaeo lutetianae-Fagetum orientalis, and Veronico chamaedryo-Piceetum orientalis) were described as belonging to humid montane coniferous and thermophilous deciduous forests within four classes. Distribution pattern of plant communities was strictly influenced by altitude, inclination, moisture, nutrient content, and light.

Formalized classification of semi-dry grasslands in central and eastern Europe

European semi-dry grasslands are among the most species-rich vegetation types in the northern hemisphere and form an important part of the habitat mosaics in the forest-steppe zone. However. there is no comprehensive evaluation of the variation in their composition and the phytosocio-logical classification of these grasslands. For the syntaxonomic revision, we used a dataset of 34,173 vegetation plot records (releves) from central and eastern Europe. which were assigned to the class Fesiuco-Bromeiea using the diagnostic species listed in the EuroVegChecklist. To determine the diagnostic species of the orders, we used a TWINSPAN classification of the whole dataset. Of the total dataset, 15,449 releves were assigned to the order Brachypodietalia pinnati. which corresponds to semi-dry grasslands. This subset was again classified using TWINSPAN. Formal definitions of the following alliances were established: Mesobromion erecti, Cirsio-Brachypodion pinnati (incl. Fragario-Trifolion montani. Agrosiio-Avenulion schellianae, Scabioso ochroleucae-Poion angustifoliae and Adonido vernalis-Stipion iirsae), Scorzonerion villosae and Chrysopogono-Danshonion. Another alliance, Armerion elongatae (=Koelerio-Phleion phleoidis p.p.). is transitional towards the class Koelerio-Corynephoreiea and its status needs further evaluation. We also established formal definitions of all of the associations of Mesobromion and Cirsio-Brachypodion within the area studied. Associations were identified using (i) a TWINSPAN classification of the whole order, (ii) TWINSPAN classifications of regionally restricted data sets (usually all Brachypodietalia plots in one country) and (iii) existing national classification schemes. All formal definitions were written in the expert system language of the JUICE program. To obtain a more complete picture of the floristic similarities and gradients. we performed a DCA ordination of the associations. Our results revealed that meadow steppes in the forest-steppe zone in eastern Europe are very similar to semi-dry grasslands in central Europe.

Vegetation composition and ecological gradients of subtropical-moist temperate Ecotonal forests of Nandiar Khuwar Catchment, Pakistan

Present study was conducted in the mixed Pinus roxburghii Surgent and Pinus wallichiana A.B. Jackson forests of Nandiar Khuwar catchment Battagram District of Pakistan. The aim of this study was to examine the spatial pattern of vegetation composition and its relationship to microclimatic and edaphic factors. Vegetation sampling was carried out using 12 stands between elevations of 1250 - 2050 m in the study area. Four plant communities were recognized through TWINSPAN classification. Life form was dominated by nanophanerophytes and leaf size spectra were dominated by microphyll. The maximum similarity index value (32.9) was recorded between P. roxburghii, P. wallichiana, Q. incana community and Q. incana, P. roxburghii, P. wallichiana community. In Bray-Curtis ordination, maximum ordination score (0.746) was recorded for axis 1. In DCA ordination, maximum gradient length (2.43) was recorded for axis 1 with eigenvalue 0.35. In CCA ordination, maximum eigenvalue was recorded for axis 1 (0.35). The total variance (inertia) in the species data was 2.15, explanatory variables account for 100%. On axis 1 the maximum correlation (−0.749) and maximum tau value (−0.565) was recorded for wet bulb. On axis 2 the maximum negative correlation value was recorded for temperature (−0.553) and maximum tau value was recorded for slope aspect (−0.480).

Evaluation of multi-causal dynamics of variability composition of patch edges in temperate forest

In this study, we examine the effect of 13 microenvironmental variables, 3 landscape variables and 8 anthropogenic pressure variables on species richness, abundance and diversity in the distribution of plant communities and the pattern of species diversity using multivariate statistics. Results of TWINSPAN classification have identified three compositional types of edge. DCA clearly distinguished these groups by the first two DCA axes. Both classification and ordination resulted in a clear demonstration of the vegetation pattern in the study area. The results obtained from the SEM showed that microenvironmental variations (canopy openness, litter layer) determine, to a large extent, the species composition of edges, and that landscape properties are correlated with these environmental variations, but anthropogenic pressures had no significant effect on them. This final model can be used as a tool for the application of management and conservation strategies in fragmented forests, as it contributes to identify the direct and indirect effects with the largest impacts on floristic variation.

Syntaxonomy of chalk outcrop vegetation of the order Thymo cretacei-Hyssopetalia cretacei

Abstract The order Thymo cretacei-Hyssopetalia cretacei Didukh 1989 combines chalk outcrop plant communities of the southwestern Central Russian Upland. Its specificity can be attributed to a rather peculiar and heterogeneous flora with a large number of endemic species. The question about its origin has caused a lively discussion, which has been going on since the late nineteenth century. Since 1989 works on the classification of these communities have frequently been carried out, but until today no unanimous decision could be reached. The purpose of our research was to conduct a critical analysis of the syntaxonomical structure of Cretaceous outcrop vegetation and to show its difference from the steppe vegetation of the class Festuco-Brometea Br.-Bl. et Tx. ex Soó 1947. The territory of our research covers the southwestern foothills of the Central Russian Upland and the Donetsk Range, located only within the steppe zone and characterised by Cenomanian chalk outcrops. In total 354 relevés were used for the analysis. The modified TWINSPAN classification was used for the analysis. Our research has shown that the order Thymo cretacei-Hyssopetalia cretacei includes twelve associations belonging to three alliances: Artemisio hololeucae-Hyssopion cretacei Romashchenko et al. 1996, Euphorbio cretophilae-Thymion cretacei Didukh 1989 and Centaureo carbonatae-Koelerion talievii Romashchenko et al. 1996.

Trophic-level differences in functional composition of the Nardus grassland vegetation

In this study, we examined floristic and functional composition of Nardus grassland of the highlands of NE Slovenia. The data-set included 55 relevés, 59 plant species, and 17 plant functional traits (PFT). The TWINSPAN classification resulted in two plant communities; calcifuge species (G1_oligotr) and another group of species characteristic of mesotrophic meadow (G2_mesotr). On the basis of selected PFT 11 out of 17 differ significantly between the groups. Group G1_oligotr had higher community-weighted mean trait values for chamaephytes (G1 = 0.09; G2 = 0.02), geophytes (G1 = 0.03; G2= 0.01), competitors (G1 = 0.43; G2 = 0.41) and plants that start flowering later (G1 = 142.84; G2 = 136.69). On the other side was G2_mesotr represented with more plants that are therophytes (G1 = 0.04; G2 = 0.09), creeping (G1 = 0.01; G2 = 0.12) and short-lived (G1 = 0.04; G2 = 0.11) and have longer flowering period (G1 = 3.24; G2 = 3.60). Differences may reflect the stronger effect of disturbance and eutrophication in G2_mesotr, probably due to intensification of grassland management (grazing) in the region. Our findings are significant in understanding the relative influence of environmental stress and disturbance within Nardus grasslands, and this may have important implications for their conservation management.

Mediterranean landscapes and plant communities relationship

From a previous landscape classification of Huelva by the Twinspan multivariate classification method, which resulted in eight landscape types, it has been proposed the hypothesis that there is a landscape types-plant communities association. The study was performed on samples of serial scrub communities, by means of a stratified sampling between landscape types. These samples were classified using both phytosociological and Twinspan methods. Through an independent process of synthesis of landscape types and community types (according to Twinspan classification), the possible association between landscapes and communities has been analysed. This analysis has been carried out by two-way contingency table between five landscape units and five plant communities. The null hypothesis that both descriptors were independent has been rejected. On the basis of the appropriate global correspondence between phytosociologic and multivariate plant community classifications, a study of the plant community variation, in accordance with the ecological characterization of the identified syntaxa, has been developed. From it has been concluded the more important role of parent material than climate variables to explain this variation. This conclusion is in agreement with the assigned role to each of them in the biogeographic scope, according to the scale of the study.

Agro ecological assessment of Siwa Oasis arable lands

A critical foundation of sustainable agriculture is to understand different agro-ecosystems components and to investigate relations between different species and environmental factors affecting their presence and expansion. The flora of Siwa Oasis agro-ecosystems was investigated and assessed. A total of 132 stands (66 in spring and another 66 in summer) were chosen to represent the study area and its soil properties during spring and summer. Cover of each species and foliage projective cover of each stand was visually estimated. Species richness, diversity and evenness were calculated for each stand. Soil analyses showed that stands could be differentiated geographically. Vegetation and soil relationships were explored using different ecological multivariate techniques. TWINSPAN classification resulted in four ecological groups in spring and four more groups in summer. DCA and DCCA clustered stands in a similar manner to the ecological groups extracted from TWINSPAN classification. Indicator species and correlated soil characteristics of each group were identified. Salinity, crop type, water availability, shade and human intervention are the major factors affecting the diversity and richness of the vegetation communities in Siwa Oasis cultivated land. Some of the species recorded are of high economic importance, highlighting a valuable opportunity to cultivate problematic soils with non-traditional crops.

Floristic composition and species diversity of urban vegetation in Bloemfontein, Free State, South Africa

Background: Urban vegetation studies have, until recently, been relatively uncommon in South Africa. Yet, natural urban vegetation is constantly competing with and greatly impacted by urbanisation. This vegetation requires proper management and needs to be conserved because it is an important ecological infrastructure.Objectives: The objectives of the study were to identify the main vegetation types within the urban open spaces in the Bloemfontein metropolitan area, and to determine the floristic composition and species diversity of the area.Methods: A total of 248 relevés were classified using the TWINSPAN classification algorithm, and relationships between the communities and the environment were determined with the Detrended Correspondence Analysis and Canonical Correspondence Analysis computer programs. Species diversity was partitioned into α-, β- and γ-diversities.Results: Within the study area, 77 plant families and 248 genera, with a total of 376 plant species, were identified. The largest families are Poaceae, Asteraceae and Fabaceae, whereas the largest genera are Eragrostis, Aristida, Cyperus, Asparagus and Senecio. The study area has high species richness and the most species-rich sites are found adjacent to rivers and streams, and also on the slopes of hills and ridges. The vegetation is classified under five major vegetation types and four sub-units, which show a distinct association with topography and soil texture.Conclusion: The urban vegetation of Bloemfontein is species-rich and should be properly managed and conserved. In particular, the wetlands and rocky outcrops on hills and ridges, which are the most threatened habitats in the study area, need special management.

Long-Term Vegetation Changes in the Pietersburg Plateau Bushveld of the Limpopo Province, South Africa: A New Floristic Assessment of the Turfloop Nature Reserve

A floristic assessment of the Turfloop Nature Reserve was undertaken, with specific reference to the vegetation structure, species of conservation importance (i.e. Red Data species, protected, endemic species, species of medicinal value and biotic and a biotic environment). Releves were compiled in 33 random sample plots placed in the study area. A TWINSPAN classification, refined by Braun-Blanquet procedures, revealed eight plant communities. A hierarchical classification, description and ecological interpretation of plant communities are presented. The general structure in terms of growth forms and dominant species of vegetation has changed, compared to a similar survey conducted 39 years ago. Three new plant communities occur and changes also occurred within existing communities. The abundance of vegetation on certain areas has decreased due to severe unsustainable exploitation of resources by surrounding villages, leading to the demise of old and the establishment of new plant communities. The study addresses the long-term changes in vegetation, including the effect of human intervention. It has implications for all involved in veld management, illustrating the effects of over-exploitation on natural resources.

Floristic Composition and Vegetation Analysis in Suez Governorate, Egypt

The present study provides a detailed depiction of the floristic composition and vegetation analysis of four habitats in Suez Governorate, Egypt. The investigated habitats include desert, waste lands, crop fields and orchards. A total of 107 species (56 annuals, 2 biennials and 49 perennials) belonging to 93 genera and 33 families were recorded in the study area. The most represented families were Asteraceae, Poaecae, Brassicaceae, Fabaceae and Chenopodiaceae. Therophytes were the most prevailing life-forms. Chorological analysis revealed that the Saharo-Sindian and Mediterranean chorotypes either pure or extended into other regions form the major component of the floristic structure. The application of TWINSPAN classification technique on the importance values of 107 plant species recorded in 40 stands representing the studied habitats produced four vegetation groups named after their dominant species. Group A: dominated by Zygophyllum coccineum, group B: dominated by Tamarix nilotica, group C: dominated by Beta vulgaris, Chenopodium murale and Melilotus messanensis and group D: dominated by Oxalis corniculata. Species richness, Shannon-Wiener and Simpson indices measurements indicated that vegetation groups D and C were the most diverse ones, followed by groups A and B. Detrended Correspondence Analysis (DCA) results indicated a reasonable segregation among these groups along the first and second axes. Linear correlation of soil variables with the importance values of some dominant species and the application of Canonical Correspondence Analysis (CCA- biplot) indicated significant correlation between species distribution of the studied habitats and the soil variables such as, soil texture, organic matter, CaCo3, pH, electrical conductivity, bicarbonates, chlorides, sodium, magnesium, pota-ssium and calcium.

Floristic Composition and Vegetation Analysis in Suez Governorate, Egypt

The present study provides a detailed depiction of the floristic composition and vegetation analysis of four habitats in Suez Governorate, Egypt. The investigated habitats include desert, waste lands, crop fields and orchards. A total of 107 species (56 annuals, 2 biennials and 49 perennials) belonging to 93 genera and 33 families were recorded in the study area. The most represented families were Asteraceae, Poaecae, Brassicaceae, Fabaceae and Chenopodiaceae. Therophytes were the most prevailing life-forms. Chorological analysis revealed that the Saharo-Sindian and Mediterranean chorotypes either pure or extended into other regions form the major component of the floristic structure. The application of TWINSPAN classification technique on the importance values of 107 plant species recorded in 40 stands representing the studied habitats produced four vegetation groups named after their dominant species. Group A: dominated by Zygophyllum coccineum, group B: dominated by Tamarix nilotica, group C: dominated by Beta vulgaris, Chenopodium murale and Melilotus messanensis and group D: dominated by Oxalis corniculata. Species richness, Shannon-Wiener and Simpson indices measurements indicated that vegetation groups D and C were the most diverse ones, followed by groups A and B. Detrended Correspondence Analysis (DCA) results indicated a reasonable segregation among these groups along the first and second axes. Linear correlation of soil variables with the importance values of some dominant species and the application of Canonical Correspondence Analysis (CCA- biplot) indicated significant correlation between species distribution of the studied habitats and the soil variables such as, soil texture, organic matter, CaCo3, pH, electrical conductivity, bicarbonates, chlorides, sodium, magnesium, pota-ssium and calcium.

Environmental drivers of freshwater macrophyte diversity and community composition in calcareous warm‐water rivers of America and Africa

Abstract This study assessed the hypothesis that spatial and environmental drivers of river macrophyte diversity and community composition differ in relative importance in calcareous river systems located in warm regions of America versus Africa. We collected aquatic vegetation and spatio‐environmental data, during 2006–11, from >200 hardwater rivers, and associated floodplain waterbodies, located up to 30° north or south of the Equator, in México, Trinidad, Brazil, Argentina, U.S.A. (Florida), South Africa, Botswana and Zambia. Species rarefaction procedures were used to assess the impacts of differing sampling effort in the two continents upon estimation of γ‐diversity (“species pool”). We then used a cluster analysis approach (two‐way indicator species analysis: TWINSPAN) to classify samples into groups based upon species composition. Variation in species richness, community composition and six spatial and environmental variables, among samples making up these groups, were compared using ANOVA and Kruskal–Wallis procedures. Regression trees and redundancy analysis were used to infer the relative importance of spatial and environmental drivers in explaining variation in local species richness and species community composition between the two continents. Sorensen's index (Cs) was calculated to estimate species turnover (β‐diversity) between African and American samples. In total, 378 macrophyte taxa were recorded, with no significant difference in mean macrophyte α‐diversity between African and American sites, but with evidence for high species turnover between the two continents (Cs = 0.17). Rarefaction analysis confirmed the existence of a larger macrophyte species pool in the hardwater rivers sampled in Africa compared to America. TWINSPAN classification identified seven sample end‐groups, only one of which contained a mix of sites from both continents. PERMANOVA and non‐metric multidimensional scaling ordination analysis confirmed significant differences in community composition present in these sample‐groups. There were substantial differences between the sample‐groups for α‐diversity, and for spatial and environmental variables. The high species turnover between Africa and America may be accounted for by geographical segregation, along with differences in aquatic habitat characteristics, and varying long‐distance dispersal capacities of individual species. The relative importance of spatial and physicochemical drivers (latitude, pH, altitude, alkalinity and electrical conductivity but not flow) differed between the continents in influencing variation in both macrophyte diversity and community composition. Latitude was a significant, although nonlinear and rather complex, spatial driver of macrophyte α‐diversity in both American and African hardwater rivers. Water chemistry variables varied in relative importance as drivers of macrophyte α‐diversity for African and American sites individually, and for all sites combined, but pH and/or electrical conductivity were more important than alkalinity in each case. In all three cases, altitude was consistently the third most important driver of α‐diversity. Spatial and environmental variables played important roles in structuring macrophyte community composition in warm‐water calcareous rivers in both America and Africa, with latitude being the strongest individual driver. Thus, this spatial variable, which is a surrogate for numerous enviro‐climatic variables, appears to be of importance in determining macrophyte distributions at large spatial scales, for the ecosystem type examined here.

A framework for quantifying the extent of impact to plants from linear construction

We present a novel framework that accurately evaluates the extent of a linear project’s effect from the variability of the structure of the plant community while avoiding interference caused by pioneer species and invasive species. This framework was based on the change of dominant species in the plant community affected by construction. TWINSPAN classification and variation of the integrated importance value (IIV) of each plant species group were used to characterize the process of change in the structure of the plant community. Indicator species group and its inflection point were defined and used to judge the extent of the effects of pipelines. Our findings revealed that dominant species in the working area of the pipeline construction were different from the original plant communities. With the disturbance decreased, the composition and structure of the plant communities gradually changed. We considered the outer limit of the area affected by the construction to be the first area in which the plant community reached a steady state and was similar to the original community. The framework could be used in the post eco-environment impact assessment of linear construction to estimate the intensity of disturbance and recovery condition.

Classification of European beech forests: a Gordian Knot?

AbstractQuestionsWhat are the main floristic patterns in European beech forests? Which classification at the alliance and suballiance level is the most convincing?LocationEurope and Asia Minor.MethodsWe applied a TWINSPAN classification to a data set of 24 605 relevés covering the whole range of Fagus sylvatica forests and the western part of Fagus orientalis forests. We identified 24 ‘operational phytosociological units’ (OPUs), which were used for further analysis. The position of each OPU along the soil pH and temperature gradient was evaluated using Ellenberg Indicator Values. Fidelity of species to OPUs was calculated using the phi coefficient and constancy ratio. We compared alternative alliance concepts, corresponding to groups of OPUs, in terms of number and frequency of diagnostic species. We also established formal definitions for the various alliance concepts based on comparison of the total cover of the diagnostic species groups, and evaluated alternative geographical subdivisions of beech forests.ResultsThe first and second division levels of TWINSPAN followed the temperature and soil pH gradients, while lower divisions were mainly geographical. We grouped the 22 OPUs of Fagus sylvatica forests into acidophytic, meso‐basiphytic and thermo‐basiphytic beech forests, and separated two OPUs of F. orientalis forests. However, a solution with only two ecologically defined alliances of F. sylvatica forests (acidophytic vs basiphytic) was clearly superior with regard to number and frequency of diagnostic species. In contrast, when comparing groupings with three to six geographical alliances of basiphytic beech forests, respectively, we did not find a strongly superior solution.ConclusionsWe propose to classify F. sylvatica forests into 15 suballiances – three acidophytic and 12 basiphytic ones. Separating these two groups at alliance or order level was clearly supported by our results. Concerning the grouping of the 12 basiphytic suballiances into ecological or geographical alliances, as advocated by many authors, we failed to find an optimal solution. Therefore, we propose a multi‐dimensional classification of basiphytic beech forests, including both ecological and geographical groups as equally valid concepts which may be used alternatively depending on the purpose and context of the classification.

Convergence and impoverishment of fen communities in a eutrophicated agricultural landscape of the Czech Republic

AbstractQuestionsOn‐going rapid loss of fen biodiversity in Central Europe is well known, but rigorous testing of this is complicated. We compared historical and present‐day vegetation plot records from a cultural landscape rich in fishponds, where recent eutrophication and water table manipulations threaten the unique fen diversity. We assess species composition change over the last 50 yr.LocationTřeboň Basin, Czech Republic.MethodsFirst, we revisited historical vegetation plots to collect present‐day data and then identified the most similar present‐day record (the present‐day counterpart) because no permanent plots were available. Second, we inferred water level, pH and conductivity (a proxy of mineral richness) using a training set of present‐day field measurements, and calculated Ellenberg indicator values. Then we applied modified TWINSPAN classification, CCA, PERMANOVA, PERMDISP and RMANOVA in order to test changes in the species composition, β‐diversity and environmental conditions between the historical records and their present‐day counterparts.ResultsFen vegetation has persisted on half of the sites. Out of four vegetation types, poor fens and especially flooded fens were over‐represented in the present‐day subset, while rich fens and quaking fens were under‐represented. Overall species composition differed between historical plots and their present‐day counterparts, even within individual vegetation types. Historical rich fens showed significantly higher β‐diversity than their present‐day counterparts, which predominantly represent flooded fens. Inferred water level and its fluctuation, Ellenberg moisture and nutrient values have increased, while inferred pH, conductivity and Ellenberg light value have decreased.ConclusionsThe historically wide array of fen vegetation has turned into a homogeneous and floristically depauperate set of acidic yet productive flooded fens with a high water level. Rich and quaking fens that were both low in nutrient availability and had a stable water level near the moss layer experienced a large and substantial reduction and have become rare in the landscape. Eutrophication combined with a lack of management has resulted in fen species persisting only in flooded fens. However, fluctuating water levels and high nutrient availability in flooded fens favour productive Sphagnum fens over the other vegetation types, and, importantly, do not support some endangered fen species.

Syntaxonomical analysis of the riparian vegetation of thePorsuk River (Eskişehir-Kütahya/Turkey)

This study is about the classification and syntaxonomic allocation of the riparian vegetation of the Porsuk River (Eskişehir-Kütahya, western part of Central Anatolia). The Porsuk is part of the Sakarya River basin and is the longest tributary of the Sakarya River. The data were collected using the phytosociological method of Braun-Blanquet and analyzed using TWINSPAN classification and NMDS ordination. Ten syntaxa were identified, all of which are more or less widespread in the nemoral and meridional zone. The woody alluvial vegetation of the study area comprises the associations Salicetum albae, Populetum albae, and Elymo-Rubetum caesii. The riparian reed bed vegetation is represented by the associations Phragmitetum australis, Schoenoplectetum tabernaemontani, Typhetum latifoliae, Typhetum angustifoliae, Cyperetum longi, Caricetum gracilis, and Galio palustris-Juncetum inflexi. The community composition, though of azonal character, suggests marked influence of biogeographical and climatic sub-Mediterranean conditions.

山西文峪河上中游森林群落多样性

PDF HTML阅读 XML下载 导出引用 引用提醒 山西文峪河上中游森林群落多样性 DOI: 10.5846/stxb201605090894 作者: 作者单位: 山西大学黄土高原研究所,山西大学黄土高原研究所,太原工业学院 环境与安全工程系,山西大学黄土高原研究所 作者简介: 通讯作者: 中图分类号: 基金项目: 科技部科技基础性工作专项资助项目（2011FY110300，2015FY110300）；山西省自然科学基金资助项目（20130110371）；我国主要灌丛植物群落调查资助项目（2015FF110300）；2016年山西省研究生教育创新项目（2016BY015） Diversity of forest communities in the upstream and middle reaches of the Wenyu River watershed, Shanxi Author: Affiliation: Institute of the Loess Plateau,Shanxi University,Institute of the Loess Plateau,Shanxi University,Department of Environmental and Safety Engineering, Taiyuan Institute of Technology,Institute of the Loess Plateau,Shanxi University Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:基于山西文峪河上中游森林群落的野外调查数据，选取植物生活型、生活史、固氮类型、传粉途径、种子传播途径等14个植物功能性状，计算丰富度指数（R）、多样性指数（H'）、均匀度指数（E）等物种多样性指数和功能丰富度指数（FRic）、功能均匀度指数（FEve）、功能分歧度指数（FDiv）等功能多样性指数，并用TWINSPAN对森林群落进行分类，Spearman秩相关分析多样性指数间及其与环境因子间的相关性，对山西文峪河上中游森林群落多样性进行研究。结果表明：青杄林种数最多（R=27），辽东栎油松林和油松林种数最少（R=16）；白桦林的H'和E最大，油松林的H'和E最小。山杨白桦林的FRic值最大，白杄林的FRic值最小；青杄林的FEve值最大，山杨白桦林的FEve值最小；山杨林的FDiv值最大，白桦林的FDiv值最小。文峪河上中游森林群落物种多样性指数与功能多样性指数间相关性不显著（P > 0.05），仅FDiv与H'呈显著负相关关系（P < 0.05）；物种多样性指数间呈极显著相关关系（P < 0.01），功能多样性指数间相关性不显著（P > 0.05），仅FRic与FEve呈显著负相关关系（P < 0.05）；随着海拔增加，物种多样性指数增加（P < 0.05或P < 0.01），但功能多样性指数减小（P < 0.01或P > 0.05）。 Abstract:Over the past 10 years, ecosystem functional diversity has played an important role in ecological research. Many studies have revealed that biodiversity has a substantial impact on ecosystem function through functional diversity, i.e., functional diversity is the factor closely related to the ecological process of biological diversity. The diversity of forest communities in the upstream and middle reach of the Wenyu River watershed, Shanxi was studied based on the field survey data. In the forest communities, we determined the growth form, life history, types of nitrogen fixation, C3/C4 type, light tolerance, leaf type, flower type, pollination mode, fruit type, seed propagation, flowering time, flowering phase, fruitage time and fruit season. These variables were used as plant functional traits to calculate species diversity indices, including richness index (R), species diversity index (H'), and evenness index (E), as well as functional diversity indices including the functional richness index (FRic), functional evenness index (FEve), and functional divergence degree index (FDiv). Classification of forest communities was analyzed using TWINSPAN and the correlation among diversity indices and between diversity indices and environmental factors were determined using Spearman's rank correlation analysis. The results indicated that:1) Based on the TWINSPAN classification results and in accordance with the principle and method of classification of vegetation, 52 forest quadrats in the upstream and middle reach of the Wenyu watershed were classified into nine formations, including Form. Betula platyphylla, Form. Picea meyeri, Form. Larix principis-ruprechtii, Form. Quercus wutaishanica, Form. Quercus wutaishanica+Pinus tabuliformis, Form. Picea wilsonii, Form. Populus davidiana+Betula platyphylla, Form. Populus davidiana and Form. Pinus tabuliformis. 2) The number of species was greatest in Form. Picea wilsonii (R=27) and Form. Quercus wutaishanica+Pinus tabuliformis, whereas Form. Pinus tabuliformis had the least (R=16); the H' and E of Form. Betula platyphylla were the largest, and they were smallest for Form. Pinus tabuliformis. 3) The FRic of Form. Populus davidiana+Betula platyphylla was largest, and it was smallest for Form. Picea meyeri; the FEve of Form. Picea wilsonii was the largest, and it was smallest for Form. Populus davidiana+ Betula platyphylla; the FDiv of Form. Populus davidiana was largest, and it was smallest for Form. Betula platyphylla. 4) There was no correlation between the forest community species diversity index and functional diversity index (P > 0.05), with only FDiv and H' being significantly negatively correlated (P < 0.05). 5) The correlation between the species diversity indices was highly significant (P < 0.01), the correlation between the functional diversity indices was not significant (P > 0.05), and FRic and FEve were significantly negatively correlated (P < 0.05). 6) The R value and altitude were highly significantly positively correlated (P < 0.01), the H' value and altitude were significantly positively correlated (P < 0.05), the H' the E values were significantly negatively correlated (P < 0.05), the FDiv value and latitude were highly significantly negatively correlated (P < 0.01), the FDiv value and altitude were highly significantly negatively correlated (P < 0.01). 7) As altitude increased, the species diversity index increased, and the linear relationship between the R and E values changed with altitude and was significant (P < 0.05); the linear relationship between the H' value and altitude was highly significant (P < 0.01), but as the functional diversity index decreased, the linear relationship between the FRic and FEve values changed with altitude was not significant (P > 0.05); the linear relationship between the FDiv value and altitude was highly significant (P < 0.01). 参考文献 相似文献 引证文献