scholarly journals Impacts of Restoration Projects on a Sahelian Woody Vegetation after 21 Years: The Simiri Plateaus (Niger) Case Study

2019 ◽  
pp. 1-12
Author(s):  
Laouali Abdou ◽  
Boubacar Moussa Mamoudou ◽  
Habou Rabiou ◽  
Ali Mahamane ◽  
Josiane Seghieri
Keyword(s):  
Vegetation Cover ◽  
Recovery Rate ◽  
Crop Yields ◽  
Basal Area ◽  
Tree Height ◽  
Woody Species ◽  
Woody Vegetation ◽  
Number Of Stems ◽  
Similar Site

To face the soil and vegetation degradation in Niger, anti-erosion structures, such as scarification of the surface of the ground, half-moons, benches, trenches, stony cordons, were built in 1989 on three Simiri plateaus. Native and introduced woody species were planted and grasses were sown within the structures. This study aims at evaluating what has become the restoration of the woody vegetation cover compared to an un-restored woody cover located on a nearby similar site. Dendrometric parameters and alpha and beta diversities of the four woody stands in 36 sampled plots were analyzed and compared. The following dendrometric values were found significantly lower in the control than in the restored stands: 3.9% against 12.4-16.8% for the recovery rate, 4.3 against 6.3-10.2 cm for the largest stem diameter, 0.2 against 0.8-1.2 m²/ha for the basal area, and 1.6 against 2.0-2.5 m for the tree height. However, the number of stems per trees was found significantly greater in the un-restored stand (6.6) than in the restored ones (1.8-2.7). The values of dendrometric parameters remained low, as well as the alpha and beta diversities whatever the stand. Nevertheless, population perceptions on the restoration impacts that were collected through focus groups indicated positive impacts on downstream crop yields.

scholarly journals Online appendix 1:Exploring an extensive dataset to establish woody vegetation cover and composition in Kruger National Park for the late 1980s

Koedoe ◽  
2014 ◽  
Vol 56 (1) ◽  
Author(s):  
Gregory A. Kiker ◽  
Rheinhardt Scholtz ◽  
Izak P.J. Smit ◽  
Freek J. Venter
Keyword(s):  
Species Richness ◽  
Vegetation Cover ◽  
National Park ◽  
Large Scale ◽  
Plant Cover ◽  
Canopy Cover ◽  
Woody Species ◽  
Kruger National Park ◽  
Tree Cover ◽  
Woody Vegetation

Woody plant cover and species composition play an important role in defining the type and function of savanna ecosystems. Approximately 2000 sites in the Kruger National Park (KNP) were surveyed by F.J. Venter over a period from 1985 to 1989, recording vegetation, soil and topological characteristics. At each of these sites (approximately 20 m × 20 m each), woody vegetation cover and species were recorded using a rapid, Braun-Blanquet classification for three height classes: shrub (0.75 m – 2.50 m), brush (2.50 m – 5.50 m) and tree (> 5.50 m). The objective of this study was to re-analyse the vegetation component of the field data, with a specific focus to provide a spatially explicit, height-differentiated, benchmark dataset in terms of species occurrence, species richness and structural canopy cover. Overall, 145 different woody species were recorded in the dataset out of the 458 species documented to occur in the park. The dataset describes a woody layer dominated by a relatively small number of widely occurring species, as 24 of the most common woody species accounted for all woody species found on over 80% of all sites. The less common woody species (101) were each recorded on 20 sites or less. Species richness varied from 12 to 1 species per site. Structural canopy cover averaged 9.34%, 8.16% and 2.89% for shrub, brush and tree cover, respectively. The dataset provides a useful benchmark for woody species distribution in KNP and can be used to explore woody species and height class distributions, as well as comparison with more recent or future woody vegetation surveys.Conservation implications: The results provided evidence that large-scale, woody vegetation surveys conducted along roads offer useful ecosystem level information. However, such an approach fails to pick up less common species. The data presented here provided a useful snapshot of KNP woody vegetation structure and composition and could provide excellent opportunities for spatio-temporal comparisons.

scholarly journals Diversité et structure de la végétation ligneuse dans la ville de Malanville au Nord-Bénin

2021 ◽  
Vol 15 (1) ◽  
pp. 129-143
Author(s):  
Baké Orou Wari ◽  
Soufouyane Zakari ◽  
Mama Djaouga ◽  
Ismaïla Toko Imorou ◽  
Ibouraïma Yabi ◽  
...  
Keyword(s):  
Land Use ◽  
Data Management ◽  
Basal Area ◽  
Woody Species ◽  
Management Tool ◽  
Survey Method ◽  
Woody Vegetation ◽  
Floristic Diversity ◽  
Milieu Urbain ◽  
The Town

La végétation urbaine a le potentiel de relever de nombreux défis environnementaux liés à la durabilité des villes. L’objectif de cette étude était de caractériser la végétation ligneuse de Malanville. La méthode de relevé phytosociologique est utilisée pour la collecte des données. L’échantillonnage aléatoire stratifié a permis d’installer 300 placeaux carrés de 1 ha, générés au hasard par l’outil « Data Management » du logiciel ArcGIS 10.5, suite à un maillage de l’armature urbaine. Le travail a permis de dénombrer 68 espèces  ligneuses réparties 58 genres et 33 familles. La diversité floristique est relativement faible et varie de façon significative (p < 0,05) selon les unités d’occupation des terres (richesse spécifique : 2,75 à 6,75 ; diversité de Shannon : 0,83 à 1,64 bits ; équitabilité de Pielou : 0,48 à 0,63). Les paramètres de structure décroissent significativement (p < 0,01) selon les unités d’occupation des terres (densité moyenne : 6,56 à 59,25 N/ha ; surface terrière : 0,77 à 4,52 m²/ha ; circonférence moyenne : 90,7 à 121,17 cm). La ville de Malanville regorge d’une importante biodiversité floristique constituée à 61% d’espèces exotiques. Dans la recherche de solutions locales aux répercussions deschangements climatiques, cette étude est un atout pour la conservation de la végétation ligneuse urbaine permettant de construire des villes plus durables, attractives et vertes.Mots clés : Diversité floristique, structure de la végétation, végétation en milieu urbain, Malanville, Bénin.English title: Diversity and structure of woody vegetation in the town of Malanville in Northern BeninUrban vegetation has the potential to meet many challenges environmental issues related to the sustainability of cities. The objective of this study was to characterize the woody vegetation of Malanville. The phytosociological survey method was used for data collection. Stratified random sampling allowed the installation of 300 square plots of 1 ha, randomly generated by the "Data Management" tool of the ArcGIS 10.5 software, following a meshing of the urban framework. The work enabled the enumeration of 68 woody species distributed in 58 genera and 33 families. The floristic diversity is relatively low and varies significantly (p < 0.05) according to land use units (specific richness: 2.75 to 6.75; Shannon's diversity: 0.83 to 1.64 bits; Pielou's equitability: 0.48 to 0.63). The structure parameters decrease significantly (p < 0.01) according to the land use units (mean density: 6.56 to 59.25 N/ha; basal area: 0.77 to 4.52 m²/ha; mean circumference: 90.7 to 121.17 cm). The town of Malanville has an important floristic biodiversity, 61% of which is made up of exotic  species. In the search for local solutions to the impacts of climate change, this study is an asset for the conservation of urban woody vegetation, enabling the construction of more sustainable, attractive and greener cities. Keywords : Floristic diversity, vegetation structure, urban vegetation, Malanville, Benin

scholarly journals Fuelwood Harvest and No Harvest Effects on Forest Composition, Structure, and Diversity of Arasbaran Forests—A Case Study

Forests ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1631
Author(s):  
Sajad Ghanbari ◽  
Christel C. Kern
Keyword(s):  
Species Diversity ◽  
Tree Height ◽  
Woody Species ◽  
Forest Composition ◽  
Stem Density ◽  
Regeneration Status ◽  
Composition And Structure ◽  
Composition Structure ◽  
The Impact

The impact of fuelwood harvesting on forest structure and composition is not clear, especially on the understudied and scarce Arasbaran forests in Iran. This research compared woody species density, species diversity, forest composition, and regeneration status in areas of continuous and ceased fuelwood harvesting in Arasbaran forests. We expected fuelwood harvesting to decrease stem density, species diversity, tree size (diameter at the breast height (DBH) and height), and shift composition away from preferred fuelwood species. We measured woody species size and frequency and identified species in three fuelwood harvest and three no harvest sites, with six sample plots (100 m × 50 m) per site. Results tended to show differences in composition, diversity, woody species height, and density. Carpinus orientalis, a preferred fuelwood species, tended to be more dominant in no harvest (importance values index (IVI) = 173.4) than harvest areas (IVI = 4.4). The diversity or richness of woody species tended to be higher in harvest (20 ± 1 species per ha) than in no harvest (14 ± 2 species per ha) areas, and other measures of diversity supported this trend as well. Harvest areas tended to also be characterized by shorter tree height and lower density of trees, a higher density of regeneration, and fewer small pole-sized trees than no harvest areas. Ongoing fuelwood harvests may further shift composition and structure away from no harvest area, compromising future fuelwood availability, but further detailed research is needed. Close to nature practices may be useful in sustaining fuelwood harvest areas and diversifying areas where fuelwood harvesting has ceased.

scholarly journals Exploring an extensive dataset to establish woody vegetation cover and composition in Kruger National Park for the late 1980s

Koedoe ◽  
2014 ◽  
Vol 56 (1) ◽  
Author(s):  
Gregory A. Kiker ◽  
Rheinhardt Scholtz ◽  
Izak P.J. Smit ◽  
Freek J. Venter
Keyword(s):  
Species Richness ◽  
Vegetation Cover ◽  
National Park ◽  
Large Scale ◽  
Plant Cover ◽  
Canopy Cover ◽  
Woody Species ◽  
Kruger National Park ◽  
Tree Cover ◽  
Woody Vegetation

Woody plant cover and species composition play an important role in defining the type and function of savanna ecosystems. Approximately 2000 sites in the Kruger National Park (KNP) were surveyed by F.J. Venter over a period from 1985 to 1989, recording vegetation, soil and topological characteristics. At each of these sites (approximately 20 m × 20 m each), woody vegetation cover and species were recorded using a rapid, Braun-Blanquet classification for three height classes: shrub (0.75 m – 2.50 m), brush (2.50 m – 5.50 m) and tree (> 5.50 m). The objective of this study was to re-analyse the vegetation component of the field data, with a specific focus to provide a spatially explicit, height-differentiated, benchmark dataset in terms of species occurrence, species richness and structural canopy cover. Overall, 145 different woody species were recorded in the dataset out of the 458 species documented to occur in the park. The dataset describes a woody layer dominated by a relatively small number of widely occurring species, as 24 of the most common woody species accounted for all woody species found on over 80% of all sites. The less common woody species (101) were each recorded on 20 sites or less. Species richness varied from 12 to 1 species per site. Structural canopy cover averaged 9.34%, 8.16% and 2.89% for shrub, brush and tree cover, respectively. The dataset provides a useful benchmark for woody species distribution in KNP and can be used to explore woody species and height class distributions, as well as comparison with more recent or future woody vegetation surveys.Conservation implications: The results provided evidence that large-scale, woody vegetation surveys conducted along roads offer useful ecosystem level information. However, such an approach fails to pick up less common species. The data presented here provided a useful snapshot of KNP woody vegetation structure and composition and could provide excellent opportunities for spatio-temporal comparisons.

scholarly journals Variabilité Structurale Des Peuplements D’arbres En Forêt De Montagne Du Parc National De Kahuzi-Biega Et Ses Environs, RD. Congo

2016 ◽  
Vol 12 (23) ◽  
pp. 88
Author(s):  
Imani Mugisho Gérard ◽  
Zapfack Louis ◽  
Bernard Riera ◽  
Mwanga Mwanga Ithe Jean-Claude ◽  
Bulonvu Franclin ◽  
...  
Keyword(s):  
Forest Type ◽  
Basal Area ◽  
Tree Height ◽  
Woody Species ◽  
Maximum Height ◽  
Altitude Range ◽  
Chi Square ◽  
Altitude Effect ◽  
Chi Square Analysis ◽  
The Impact

This work aims to determine the change in the diametric structure, density, basal area, height and dominance of trees dbh ≥ 10 cm depending on altitude range or forest types. The study was conducted in 30 ha in Kahuzi Biega National Park and surrounding areas in DR Congo. In total, 16,797 individual trees were surveyed. The number of family, genus and species regress following the altitudinal gradient as the density increases. Mountain ecosystems in Kahuzi-Biega and its surroundings are dominated by Meliaceae, Euphorbiaceae, Moraceae, Fabaceae and Rubiaceae families. The Chi square analysis showed that the diametric structure of vegetation succession following a progressive dynamic and varies according to altitude gradient. The average basal area was 35 m²/ha. The analysis of variance (ANOVA) and post hoc Tukey test does not prove the impact of altitude on the basal area. But it becomes low in elevation due to the reduced diameter of the trees. The vertical structure was analyzed according to the classification IUFRO (International Union of Forest Research Organizations). The maximum height was 48 m and becomes lower in altitude. The tree height diameter relationship varies according altitude range so that the models H/D in this area should be developed for each forest type. We determine that the dominance of woody species following the altitude effect; only Strombosia scheffleri and Xymalos monospora dominated by its basal area, abundance and frequency of the various altitude horizons.

scholarly journals A protocol for sampling vascular epiphyte richness and abundance

2009 ◽  
Vol 25 (2) ◽  
pp. 107-121 ◽  
Author(s):  
Jan H. D. Wolf ◽  
S. Robbert Gradstein ◽  
Nalini M. Nadkarni
Keyword(s):  
Tree Height ◽  
Dry Weight ◽  
Mantel Test ◽  
Tree Size ◽  
Tree Level ◽  
Trunk Diameter ◽  
Host Trees ◽  
Epiphyte Communities ◽  
Vascular Epiphyte

Abstract:The sampling of epiphytes is fraught with methodological difficulties. We present a protocol to sample and analyse vascular epiphyte richness and abundance in forests of different structure (SVERA). Epiphyte abundance is estimated as biomass by recording the number of plant components in a range of size cohorts. Epiphyte species biomass is estimated on 35 sample-trees, evenly distributed over six trunk diameter-size cohorts (10 trees with dbh > 30 cm). Tree height, dbh and number of forks (diameter > 5 cm) yield a dimensionless estimate of the size of the tree. Epiphyte dry weight and species richness between forests is compared with ANCOVA that controls for tree size. SChao1 is used as an estimate of the total number of species at the sites. The relative dependence of the distribution of the epiphyte communities on environmental and spatial variables may be assessed using multivariate analysis and Mantel test. In a case study, we compared epiphyte vegetation of six Mexican oak forests and one Colombian oak forest at similar elevation. We found a strongly significant positive correlation between tree size and epiphyte richness or biomass at all sites. In forests with a higher diversity of host trees, more trees must be sampled. Epiphyte biomass at the Colombian site was lower than in any of the Mexican sites; without correction for tree size no significant differences in terms of epiphyte biomass could be detected. The occurrence of spatial dependence, at both the landscape level and at the tree level, shows that the inclusion of spatial descriptors in SVERA is justified.

scholarly journals Woody Vegetation Cover, Attrition, and Patch Metrics over Eight Decades in Central Texas, United States

2021 ◽  
Vol 78 ◽  
pp. 54-66
Author(s):  
Edward C. Rhodes ◽  
Jay P. Angerer ◽  
William E. Fox ◽  
Jason R. McAlister
Keyword(s):  
United States ◽  
Vegetation Cover ◽  
Woody Vegetation ◽  
Central Texas

scholarly journals Deriving Tree Size Distributions of Tropical Forests from Lidar

2021 ◽  
Vol 13 (1) ◽  
pp. 131
Author(s):  
Franziska Taubert ◽  
Rico Fischer ◽  
Nikolai Knapp ◽  
Andreas Huth
Keyword(s):  
Size Distribution ◽  
Spatial Scales ◽  
Basal Area ◽  
Tree Height ◽  
Tree Size ◽  
Diameter Distribution ◽  
Forest Inventories ◽  
Allometric Relations ◽  
Lidar Measurements ◽  
Derived Data

Remote sensing is an important tool to monitor forests to rapidly detect changes due to global change and other threats. Here, we present a novel methodology to infer the tree size distribution from light detection and ranging (lidar) measurements. Our approach is based on a theoretical leaf–tree matrix derived from allometric relations of trees. Using the leaf–tree matrix, we compute the tree size distribution that fit to the observed leaf area density profile via lidar. To validate our approach, we analyzed the stem diameter distribution of a tropical forest in Panama and compared lidar-derived data with data from forest inventories at different spatial scales (0.04 ha to 50 ha). Our estimates had a high accuracy at scales above 1 ha (1 ha: root mean square error (RMSE) 67.6 trees ha−1/normalized RMSE 18.8%/R² 0.76; 50 ha: 22.8 trees ha−1/6.2%/0.89). Estimates for smaller scales (1-ha to 0.04-ha) were reliably for forests with low height, dense canopy or low tree height heterogeneity. Estimates for the basal area were accurate at the 1-ha scale (RMSE 4.7 tree ha−1, bias 0.8 m² ha−1) but less accurate at smaller scales. Our methodology, further tested at additional sites, provides a useful approach to determine the tree size distribution of forests by integrating information on tree allometries.

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