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Ecological distribution and population structure of Litsea glaucescens(Lauraceae)in the ravines of Sierra Fría and Sierra Laurel,Central Mexico

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Journal of Mountain Science 2022年第7期19卷 1945-1960页

作者： Mara Irais FLORES-GALLEGOS Edmundo GARCIA-MOYA Angelica ROMERO-MANZANARES Mario LUNA-CAVAZOS Martin Alfonso MENDOZA-BRISENO Heike VIBRANS Posgrado en Botánica Colegio de PostgraduadosCampus Montecillo.Km 36.5carretera México-TexcocoMontecilloTexcocoEdo.de México56230México Colegio de Postgraduados Campus Veracruz.Carretera Jalapa Veracruz Km 88.5Altamirano91690VeracruzMéxico

Litsea glaucescens Kunth(Mexican bay leaf,laurel)has a wide distribution in Mexico,growing at both riparian and rupicolous environments in the mountainous region of the Central Highlands of the *** Fría-Sierra Laurel is a protected natural area covered by a dry *** Mexican bay leaf is associated with the oak forest,especially on *** species has been considered at risk in recent *** research is focused on analyzing the elements of the environment of the ravines,which are influencing the distribution and establishment of laurel populations in the *** mountainous regions of Aguascalientes were selected,Sierra Fría and Sierra *** ravines of the basin were selected to obtain environmental *** registered were topographic,edaphic,and *** component analysis was used to identify ecological factors associated with the presence of *** bay leaf populations were registered in 10 *** the structural level in the community,29 woody species were registered,Mexican bay leaf had an importance value index of 15.8,ranking 10th among all *** of laurel were classified by size classes(S,individuals with heights ranging from 0 to 20 cm;S,heights ranging from 0.2 to 1.0 m;S,heights between 1 and 2 m with light trace of flowering;S,heights greater than 2 m with flowering greater than 30% of the canopy;and S,individuals with heights greater than 5 m,curved trunk and basal regrowth)to obtain the population *** importance index value for all the species in the riparian community was calculated to the community *** factors that characterized the presence of Mexican bay leaf were a high percentage of rock coverage(90%),less mulch depth,and sandy loam shallow *** that showed higher cation exchange capacity had a higher presence of individuals of the S,S,and Ssize *** Sindividuals were found in shady places with 97% of intercepted *** o

关键词： Dry Forest Ephemeral stream importance value index Mexican bay leaf Population structure Principal Component Analysis

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

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Journal of Forestry Research 2018年第5期29卷 1241-1249页

作者： S.C.Das M.S.Alam M.A.Hossain Institute of Forestry and Environmental Sciences University of Chittagong

Fasiakhali Wildlife Sanctuary is a protected area composed of tropical remnant rainforest that harbor substantial number of large,old Garjan（Dipterocarpus spp.）*** 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 *** forest is low in plant diversity as represented by Shannon–Wiener diversity and Simpson Dominance *** turbinatus was the most dominant species with maximum relative density,frequency,dominance,and importance value *** firmum and Tectona grandis followed in terms of *** structural composition indicated higher number of individuals in the medium growth classes（41 to 〈 511 cm DBH and 16–20 m height ranges）,whereas *** was the only species that dominated most of the growth *** stem density in lower growth classes indicated meager recruitment of regeneration which may be due to lower annual precipitation,increased grazing and *** study will help to understand the patterns of tree species composition and diversity in the remnant dipterocarp forests of *** will also contribute to identifying threatened plants to undertake *** based conservation and sustainable management of the Fasiakhali Wildlife Sanctuary.

关键词： Species diversity Structural composition Protected area importance value index Cluster analysis

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Vegetation Structure and Regeneration Status of the Western Escarpment of the Rift Valley of the Gamo Zone, Southern Ethiopia

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Open Journal of Ecology 2022年第1期12卷 94-111页

作者： Temesgen Dingamo Serekebirhan Takele Zerihun Woldu Sebsebe Demissew Biodiversity Conservation and Research Center College of Natural Science Arba Minch University Arba Minch Ethiopia Department of Biology College of Natural Science Arba Minch University Arba Minch Ethiopia Department of Plant Biology & Biodiversity Management College of Natural & Computational Sciences Addis Ababa University Addis Ababa Ethiopia

Understanding the structure and regeneration of forest resources contributes to identifying the elements of diversity, endemism, threatened and endangered species. This study was conducted in the western escarpment of the Rift valley of the Gamo Zone, Southern Ethiopia. The main objective was to investigate structure and regeneration status of the study area. A systematic sampling method was used to collect vegetation data from a total 102 quadrats, each 20 × 20 m (400 m2) and five 1 × 1 m (1 m2) sub-quadrats were established at the four corners and at the centre for sapling and seedling estimation. Tree and shrub species were listed;Height (H ≥ 1.5 m) and DBH ≥ 2 cm were measured and recorded. R-statically software and Microsoft Excel were used to record and analyse the data. A total of 126 plant species belonging to 43 families and 90 genera were identified. The most dominant families were Fabaceae, followed by Anacardiaceae and Euphorbiaceae. Most frequent species were Euclea divinorum (84.3%), followed by Rhus natalensis (83.3%), Terminalia brownii (74.5%). DBH class ≤ 5cm had highest density (63.6%) and DBH ≥ 25.1 cm had the lowest density (0.87%). Three population patterns have been observed;inverted J, J-shaped and irregular shaped. 93% of species had IVI values b/n 1 - 4, 65% of species IVI values values ≥ 5.28. Pappea capensis, Combretum molle, Terminalia brownii, Euclea divinorum had highest IVI values. In the vertical stratification, lower story was 91.3% of the individuals. Only a few species contributed to the high density of saplings (440.2/ha) and seedlings (825.49/ha) while most had very little or no saplings and seedlings at all. Thus, in order to revert the current forest structure and regeneration to the previous natural state, it is considered important to minimize the influence of the human interference, grazing and raising awarene

关键词： importance value index Regeneration Seedling/Sapling Vegetation Structure

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Species composition, stand structure, and regeneration status of tree species in dry Afromontane forests of Awi Zone, northwestern Ethiopia

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Ecosystem Health and Sustainability 2019年第1期5卷 199-215,I0020页

作者： Getaneh Gebeyehu Teshome Soromessa Tesfaye Bekele Demel Teketay Center for Environmental Science in Addis Ababa University Addis AbabaEthiopia Ethiopian Environment and Forestry Research Institute Addis AbabaEthiopia Department of Crop Science Botswana University of Agriculture and Natural ResourcesGaboroneBotswana

Species composition,structure,and regeneration status of trees were assessed in five dry Afromontane *** each of the forests,trees having≥5 cm diameter at breast height were identified and measured in 80 quadrats(20×20m^(2)).We compared tree species composition and similarities,stem densities,frequencies,basal area and importance value index of *** index was calculated to 13.3%in the least disturbed and 22.5%in highly disturbed forests.A total of 1,655 individuals representing 38 species and 28 families were *** tree densities varied from 364.1 to 664.1stem ha^(−1) with an average basal area of 20.7m^(2) ha^(−1).The analysis showed significant differences in basal areas of tree species between the least and highly disturbed *** densities ranged from 2000 to 8162.5 stem ha^(−1) and sapling densities ranged from 512.5 to 2562.5 stem ha^(−1).The anthropogenic disturbances revealed high degradation of population structure and regeneration statutes of the trees in the studied forest *** conclusion,the study provided empirical results on the dominance,population structure,importance value and regeneration status of tree species,which would be instrumental for the development of successful rehabilitation strategies for the studied forests.

关键词： Basal area disturbances importance value index regeneration specie composition similarity topographic factors

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Tree Species Composition and Diversity in the Riparian Forest of Lake Barombi Kotto, Cameroon

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American Journal of Plant Sciences 2021年第1期12卷 127-145页

作者： Awo Miranda Egbe Pascal Tabi Tabot Fonge Beatrice Ambo Department of Plant Science University of Buea Buea Cameroon Department of Agriculture Higher Technical Teachers’ Training College Kumba University of Buea Buea Cameroon

Tree species composition and diversity were investigated in the riparian forest around Lake Barombi Kotto, Cameroon. This study aimed at determining the tree species composition, population structure, and providing evidence of anthropogenic disturbances in the riparian forest of Lake Barombi Kotto. The objectives were to determine the tree species composition and diversity in the riparian forest around Lake Barombi Kotto, to elucidate the forest structure and to document the anthropogenic disturbances in this forest. Five plots were laid within which the tree enumeration and measurement of dbh were carried out. Trees were identified using scientific identification keys in the Flora of West Africa. Disturbance scores were given to each site by qualitatively assessing various disturbances. A total of 340 trees belonging to 70 plant species, 63 genera and 28 plant families were enumerated. Shannon-Wiener diversity varied across sites, with the highest value (H = 3.45) recorded in Tung and the lowest (H = 2.21) in Malenda. Population structure differed across sites, the largest stand basal area of 43.78 m2/ha was recorded in Bondokombo while the smallest (2.15 m2/ha) was recorded in the Sacred Island. Cecropia

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

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Open Journal of Forestry 2021年第1期11卷 37-46页

作者： Khalid A E Eisawi Hong He Tayyab Shaheen Emad H. E. Yasin College of Forestry Northwest A & F University Yangling China College of Forest & Range University of East Kordofan Rashad South Kordofan Sudan College of Forestry Key Laboratory of National Forestry and Grassland Administration on Management of Forest Bio-Disaster Northwest A & F University Yangling China Faculty of Forestry University of Khartoum Khartoum North Postal Code 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

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