scholarly journals Evaluation of structure and natural regeneration status of woody plant species in sudanian domain : Case of eastern part of National Park of Sena Oura, Chad

2018 ◽  
Vol 3 (5) ◽  
pp. 1571-1581
Author(s):  
Gilbert Todou ◽  
Salomon Dedangsou ◽  
Adamou Ibrahima
Fire Ecology ◽  
2020 ◽  
Vol 16 (1) ◽  
Author(s):  
Jan W. van Wagtendonk ◽  
Peggy E. Moore ◽  
Julie L. Yee ◽  
James A. Lutz

Abstract Background The effects of climate on plant species ranges are well appreciated, but the effects of other processes, such as fire, on plant species distribution are less well understood. We used a dataset of 561 plots 0.1 ha in size located throughout Yosemite National Park, in the Sierra Nevada of California, USA, to determine the joint effects of fire and climate on woody plant species. We analyzed the effect of climate (annual actual evapotranspiration [AET], climatic water deficit [Deficit]) and fire characteristics (occurrence [BURN] for all plots, fire return interval departure [FRID] for unburned plots, and severity of the most severe fire [dNBR]) on the distribution of woody plant species. Results Of 43 species that were present on at least two plots, 38 species occurred on five or more plots. Of those 38 species, models for the distribution of 13 species (34%) were significantly improved by including the variable for fire occurrence (BURN). Models for the distribution of 10 species (26%) were significantly improved by including FRID, and two species (5%) were improved by including dNBR. Species for which distribution models were improved by inclusion of fire variables included some of the most areally extensive woody plants. Species and ecological zones were aligned along an AET-Deficit gradient from cool and moist to hot and dry conditions. Conclusions In fire-frequent ecosystems, such as those in most of western North America, species distribution models were improved by including variables related to fire. Models for changing species distributions would also be improved by considering potential changes to the fire regime.


2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Abyot Dibaba ◽  
Teshome Soromessa ◽  
Alemayehu Kefalew ◽  
Admassu Addi

This study was conducted in Agama Forest in Kafa Zone, Southwestern Ethiopia, to assess species diversity, vegetation structure, and regeneration status of woody species. A systematic sampling technique was employed to collect vegetation data. Sixty (60) sample plots of 25 m × 25 m were laid at 300 m intervals all along ten grids interspaced 800 m apart. Sample plots of 25 m × 25 m were used to record DBH and H of all woody plant species reaching a DBH >2.5 cm and height >2 m. For the inventory of seedling and sapling, two subplots of 2 m × 5 m were used at the beginning and the end of the baseline on opposite sides of the main quadrat. Vegetation data such as DBH, height, seedling, and sapling density of woody species were recorded in each plot. Altogether, 72 woody plant species of 65 genera and 35 families were identified. Analysis of selected tree species showed diverse population structures. This study showed that small trees and shrubs dominated the Agama Forest, which revealed its status under a secondary regeneration stage. Study on the structure and regeneration of some woody species indicated that there are species that require urgent conservation measures. Sound management and monitoring, as well as maintenance of biodiversity and cultural and economic values of the forest, require conservation activities that encourage sustainable uses of the forest and its products.


Insects ◽  
2018 ◽  
Vol 9 (4) ◽  
pp. 189
Author(s):  
N’golo Koné ◽  
Kolotchèlèma Silué ◽  
Souleymane Konaté ◽  
Karl Linsenmair

Termites are one of the major components of tropical ecosystems. However, the ecological and biological variables determining the structure of their communities within natural habitats are less documented in general and especially in the Comoe National Park, a Sudano-Guinean savanna zone located in the north-eastern part of Côte d’Ivoire (West Africa). Using a standardized method of belt transects, the structure of termite’s communities was estimated within habitats differing in the structure of their vegetation, soil characteristics, and the disturbance level caused by annual occurrences of bushfires. The effect of a set of environmental variables (habitat type, occurrence of annual bushfire, woody plant density, woody plant species richness, and soil physicochemical parameters) was tested on the habitat-specific recorded termite species. Sixty species of termites belonging to 19 genera, seven subfamilies and two families, namely Rhinotermitidae (Coptotermitinae and Rhinotermitinae) and Termitidae (Apicotermitinae, Cubitermitinae, Macrotermitinae, Nasutitermitinae, and Termitinae) were sampled. These species were assigned to the four feeding groups of termites: fungus growers (18 species), wood feeders (17 species), soil feeders (19 species) and the grass feeders (6 species). The highest diversity of termites was encountered in forest habitats, with 37 and 34, respectively, for the gallery forest and the forest island. Among savanna habitats, the woodland savanna was identified as the most diversified habitat with 32 recorded species, followed by the tree savanna (28 species) and the grassy savanna (17 species). The distribution of termite species and their respective feedings groups was determined by the habitat type and a set of environmental variables such as Woody Plant Diversity (WPD), Woody plant Families Diversity (WPFD), and Organic Carbon (OC). The annual Fire Occurrence (FO) was found to indirectly impact the characteristics of termite assemblages within natural habitats via their respective Herbaceous Species Richness (HSR) and Woody Plant Species Richness (WPSR). In summary, the spatial heterogeneity of the Comoe National Park, modeled by the uncontrolled annual bushfire, offers a diversified natural habitat with an important variety of termite-habitat-specific species, probably due to the food preference of these organisms and its relatively good conservation status.


2016 ◽  
Vol 8 (2) ◽  
pp. 32-40
Author(s):  
Camara Mariama ◽  
D S J Gbemavo Charlemagne ◽  
K Salako Val egrave re ◽  
N Kouame Fran ccedil ois ◽  
Sambou Bienvenu ◽  
...  

2021 ◽  
Vol 2021 ◽  
pp. 1-22
Author(s):  
Semegnew Tadese ◽  
Teshome Soromessa ◽  
Tesefaye Bekele ◽  
Getaneh Gebeyehu

The aim of this study was to analyse the species composition, structures, and regeneration of woody plant species and the impacts of site factors on the natural regeneration of tree species in four study sites of MFBR. The vegetation data were collected systematically in 140 plots with the size of 400 m2 for trees; 25 m2 for seedlings, saplings, shrubs, and lianas; and 1 m2 for herbs. Individual tree and shrub DBH ≥ 5 cm were measured and counted. The diameter at breast height (DBH), frequency, basal area, importance value index (IVI), and density were used for vegetation structure description and regeneration. A total of 158 plant species belonging to 115 genera, 56 families, and 80 species (51%) trees, 26 (16%) shrubs, 19 (12%) herbs, and 33 (21%) lianas were identified and recorded. The most dominant families were Euphorbiaceae, Rubiaceae, and Moraceae, each represented by 13 species (7.4%), 12 species (6.8%), and 10 species (5.7%), respectively. The tree densities varied from 1232 to 1478 stem ha−1, sapling density 176.8 to 708.7 stem ha−1, and seedling density 534.7 to 1657.5 stem ha−1, with an average basal area of 63.6 m2 in the study sites. Dracaena afromontana was the most frequent woody species in the MFBR occurring in 90% followed by Celtis zenkeri (65%) and Pouteria altissima (62.5%). The regeneration status of all the woody plant species was categorised as “not regenerate” (9.6%), “poor” (30.7%), “fair” (59.5%), and “good” (10.8%) in all sites. The correlation result between natural regeneration and site factors revealed both positive and negative relationships. However, the main threat to the biosphere reserve is illegal logging for different purposes. Therefore, awareness creation on sustainable forest management, utilisation, conservation of priority species, and livelihood diversification to the local community and encouraging community and private woodlot plantation in the transitional zone of biosphere reserves are recommended.


2017 ◽  
Vol 1 (1) ◽  
pp. 40-53
Author(s):  
SISAY TEGEGNE ◽  
BIKILA WORKINEH

Tegegne S, Workineh B. 2017. Vegetative structure, floristic composition and natural regeneration of a species in Ylat Forest in Meket Woreda, Northeastern Ethiopia. Asian J For 1: 40-53. The natural forest of Ylat in Meket Woreda, Northeastern Ethiopia was examined to decide the vegetative structure, floristic formation and natural regeneration of woodland species and to supply data on sustainable administration of the woody plants in specific and the woodland founts in common. Systematic sampling design was used in this study to gather vegetation information. For each of the sampling sites, five transect lines having fiftyfour primary plots with 400 m2 (20m × 20m) each were laid out to gather the information on woody species along 200m line transects. A total of 60 vascular plant species having a place to 41 families and 56 genera were identified of which 13 (21.67%) were trees, 31 (51.67%) bushes, 6 (10%) climbers and 10 species (16.66) of herbs. Of all the families, Lamiaceae (8.33%) and Fabaceae, Rosaceae, Solanaceae and Euphorbiaceae 3 species (5%) were the most overwhelming woody plant species and followed by Sapindaceae, Aloaceae, Ranunclaceae, Poaceae, Oleaceae, Polygonaceae and Cucurbitaceae contains 2 species each (3.33%). A total of 2652 woody plant species individuals (1227.77 individual/ha) were found of which 405 individuals were Myrsine africana and 19 individuals were Millettia ferruginea and 20 individuals were Dombeya torrida. This data showed the highest and the lowest number of woody plant species. The thickness of woody species with DBH ≥ 2.5cm was 1227.77 individual/ha, basal zone was 1 m2 /ha, frequency of woody species was 258. The overall Shannon diversity and evenness of woody species was 2.94 and 0.84 respectively, demonstrating that the diversity and evenness of woody species within the timberland is moderately high. The woody plant species having the highest importance value index (IVI) were Erica arborea (36.31) followed by Allophylus abyssinicus (28.65) whereas Hagenia abyssinica, Myrica salicifolia, Euphorbia tirucalli, Calpurnia aurea were the lowest IVI and should be given conservation priority. Finally, this study showed that the population structure of the most woody plant species in Ylat Timberland was in a great state of regeneration recruitment level.


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