scholarly journals Floristic Composition, Structure, and Species Associations of Dry Miombo Woodland in Tanzania

2014 ◽  
Vol 2014 ◽  
pp. 1-15 ◽  
Author(s):  
Ezekiel Edward Mwakalukwa ◽  
Henrik Meilby ◽  
Thorsten Treue

For the majority of forest reserves in Tanzania, biodiversity is poorly documented. This study was conducted to assess species richness (woody species), diversity, and forest structure and to examine relationships between species occurrence and topographic and edaphic factors in the Gangalamtumba Village Land Forest Reserve, a dry Miombo woodland area in Tanzania. A total of 35 nested circular plots with radii of 5, 15, and 20 m were used to collect data on woody species and soil samples across the 6,065 ha community-managed forest reserve. Stumps were measured 20 cm above ground. A total of 88 species belonging to 29 families were identified. Generally forest structure parameters and diversity indices indicated the forest to be in a good condition and have high species richness and diversity. Vegetation analysis revealed four communities of which two were dominated by the family Caesalpiniaceae, indicating large variation of site conditions and possible disturbances in the study area. The high level of diversity of woody species and the high basal area and volume indicate that the forest is in good condition, but the effect of anthropogenic activities is evident and stresses the need for proper management to maintain or enhance the present species diversity.

2021 ◽  
Vol 22 (3) ◽  
pp. 43-50
Author(s):  
D.M. Taiwo ◽  
S.I. Udoh ◽  
S.O. Olaoti-Laaro ◽  
O.R. Jeminiwa ◽  
M.S. Jeminiwa

The Assessment of forest species composition and species diversity is essential in understanding the status of tree population and diversity for conservation purpose. Olokemeji forest reserve is situated in the lowland rain  forest of south-western Nigeria and it occupies a total land area of 58.88 km2 . Six study plots of 50m2 each were randomly selected and designated as Frequently Burnt Plot 1, Frequently Burnt Plot 2, Harvested Plot, Unharvested Unburnt Plot, Arable Plot 1 and Arable Plot 2 for the purpose of assessment of species diversity and distribution of woody species. Seven species of trees were identified belonging to five families. One hundred and eighty two stands were enumerated, with Unharvested Unburnt Plot having the highest number of trees at 50. The dominance index for the woody flora was 1 in Frequently Burnt Plot 1 and 2 as well as Arable Plot 1 and 2 except for the Harvested Plot that had the lowest (0.29) while the Unharvested Unburnt Plot had 0.75. Highest species richness was recorded at the Harvested Plot at 0.71. The species diversity in Harvested Plot was low (1.54), while it was extremely low in Unharvested Unburnt Plot (0.43). Evenness index was lowest in the Unharvested Unburnt Plot at 0.43. Tectona grandis had the highest relative importance value in the Frequently Burnt Plot 1. The low species richness and species diversity is a direct indication of anthropogenic interference in the study plots and the forest reserve; this requires urgent mitigation to prevent a total loss of its structure and function as expected of a forest reserve. Keywords: Species, Diversity, Evenness, Anthropogenic, Forest, Dynamics


2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Annissa Muhammed ◽  
Eyasu Elias

Bale Mountains National Park is one of the protected areas in Ethiopia that holds the largest area of Afroalpine habitat in Africa and the second largest stand of moist tropical forest. Nevertheless, human settlements, overgrazing, and recurrent fire are the main problems in the park. This study aimed to determine the effects of human-induced landscape change in floristic composition and structure in the park. The vegetation data were collected systematically from 96 sample plots laid along 24 line transects in the edge and interior habitats of the six land cover types. Vegetation composition and landscape structural analysis were made using R software version 3.5.2 and FRAGSTATS version 4.2.1, respectively. Patch number was strong and positively affected species richness (r = −0.90, p < 0.05 ), diversity (r = −0.96, p < 0.01 ), and basal area (r = −0.96, p < 0.001 ), whereas mean patch size was strong and negatively influenced species richness (r = 0.95, p < 0.05 ), diversity (r = 0.87, p < 0.05 ), and basal area (r = 0.82, p < 0.05 ). The overall species richness, Shannon diversity index, and Margalef index were significantly higher in the edge habitat; however, the mean basal area of woody species was significantly higher in the interior habitat at p < 0.05 . This study uncovered that the park is floristically rich and diverse, and it provides a variety of ecological and economic benefits to the surrounding community and to the nation at large. However, these benefits are gradually declining due to the high level of anthropogenic activities in the park. Thus, integrated environmental management strategy that blends with sustainable use of natural resources should be implemented to minimize the threats.


2014 ◽  
Vol 14 (1) ◽  
Author(s):  
Macielle Macedo Coelho ◽  
André Márcio Amorim

The aim of this study is to survey the angiosperms of two montane forest remnants in the southern Bahia, Brazil: Corcovado (SCO) and Pedra Lascada (SPL). Both fragments are located in the municipality of Almadina and Barro Preto, respectively, and are 18 km distant from each other. We sampled 899 species of angiosperms distributed in 437 genera and 116 families. The SCO was the richest area with 678 species, distributed in 367 genera and 100 families. SPL showed 466 species in 269 genera and 88 families. The percentage of species identified was 85.8% and of this total, 37.7% are endemic to the Atlantic Forest, 11.2% are endemic to southern Bahia and northern Espírito Santo and 7% are disjunct between the Atlantic Forest and Amazon. The remaining percentages (44.3%) were of species widely distributed. The richest families in the two areas were Orchidaceae (10%), Rubiaceae (7%), Bromeliaceae (5.5%), Melastomataceae (4.2%) and Poaceae (4%). The richest genera were Psychotria (2%),Piper (1.8%), Ocotea (1.6%),Vriesea (1.5%) and Peperomia (1.4%). More than half of the recorded species showed non-arboreal habit, regarding life forms documented. That comes against the assertion that many authors in the tropical forests, where species richness in angiosperms is expected for non-woody species, especially in montane forests. Twelve species have been identified as new, but seven others already described from collections previously obtained in these two areas. Orchidaceae, Rubiaceae, Poaceae and Bromeliaceae showed significant richness in this study these families are commonly reported as the richest in other inventories in the Atlantic Forest in southern Bahia reinforcing their importance to the regional flora. The high levels of richness, endemism, and the growing numbers of new taxonomic discoveries from the SPL and SCO sites indicate the biological importance of these two forest remnants. The implementation of parks or other protected environmental reserves would be essential to the conservation of its species.


Land ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 4 ◽  
Author(s):  
Mulugheta Ghebreslassie Araia ◽  
Paxie Wanangwa Chirwa ◽  
Eméline Sêssi Pélagie Assédé

Using landscape moderation insurance and Intermediate Disturbance Hypothesis (IDH) as frameworks, this study assessed the response of local assemblage among different land use regimes (mean β-diversity), using the Jaccard dissimilarity matrix in contrasting Human Modified Forest Landscapes (HMFLs). The study was conducted at the relatively simplified Mafhela Forest Reserve and the complex Thathe Vondo Forest Reserve in South Africa. The patterns of overall β-diversity between HMFL and State-protected Indigenous Forests (SIF) were compared and the leading change drivers were then untangled. This study found that human disturbance affects mean β-diversity of local assemblages among land use regimes between the two HMFLs in an ecologically contrasting manner. The HMFL in Mafhela Forest Reserve had distinct local assemblages among land use regimes and did not conform to the expectation of IDH. On average, HMFL had the same average local species richness as SIF, mainly due to change in species composition (species replacement) induced by land use disturbance. Land use intensity gradient was the leading change driver to explain the overall β-diversity of the Mafhela Forest Reserve. The findings in the Thathe Vondo Forest Reserve were in contrast with the Mafhela Forest Reserve. Although on average the HMFL had the same local species richness as SIFs, this was mainly due to a trade-off of species gain in trees along the rivers and streams and species loss in Culturally Protected Areas (sacred forests) (CPA) as expected by IDH. The contrasting findings imply that the effectiveness of any alternative conservation strategy is context-dependent. The resilience of local assemblages and conservation value of HMFL depends on the condition of the overall forest landscape complexity and cannnot be captured by one theory, nor by one species diversity matrix (e.g., β-diversity or Richness). It thus demands the application of complementary theoretical frameworks and multilevel modeling.


1970 ◽  
Vol 7 (7) ◽  
pp. 76-79 ◽  
Author(s):  
Kuber Prasad Bhatta ◽  
Ram Prasad Chaudhary

One of the easiest and the most common way to estimate the biological diversity at a place is to enumerate the organisms at species level, which helps to find the basic patterns of biodiversity at the place. A sound knowledge on floristic composition of particular area is essential to understand the resources, their sustainable use and conservation purposes. Altogether 600 specimens were collected from the Upper Manang area covering an elevation gradient of 2600m to 5200m from sea level, and of which 220 species belonging to 138 genera and 50 families were identified up to species level and used to estimate species richness. Of the total identified species, greatest diversity was found within the families Compositae and Labiatae, comprising 14 and 11 genera, respectively. Similarly, the greatest species diversity was found within the genera Potentilla (12 species) and Primula (6 species). Second order polynomial regression showed unimodal pattern of species richness along elevation gradient, showing greatest species richness between 3500m to 4000m altitude, whereas no any angiosperm species was encountered beyond 5100m. Key words: Species diversity; Grassland; Cultivated land; Manang. DOI: 10.3126/sw.v7i7.3831 Scientific World Vol.7(7) 2009 pp.76-79


2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
J. Kimaro ◽  
L. Lulandala

This paper reports on the findings of an ecological survey conducted in Ngumburuni Forest Reserve, a biodiversity rich forest reserve within the coastal forests of Tanzania. The main goal of this study was to determine the influence of uncontrolled anthropogenic activities on tree species diversity and composition within the forest ecosystem. It was revealed that economic activities including logging, charcoaling, and shifting cultivation were the most important disturbing activities affecting ecological functioning and biodiversity integrity of the forest. Further to this, we noted that the values of species diversity, composition, and regeneration potential within the undisturbed forest areas were significantly different from those in heavily disturbed areas. These observations confirm that the ongoing human activities have already caused size quality degradation of useful plants, enhanced species diversification impacts to the forest ecosystem, and possibly negatively affected the livelihoods of the adjacent local communities. Despite these disturbances, Ngumburuni forest reserve still holds important proportions of both endemic and threatened animal and plant species. The study suggests urgent implementation of several conservation measures in order to limit accessibility to the forest resources so as to safeguard the richness and abundance of useful biodiversity stocks in the reserve.


2021 ◽  
Vol 13 (13) ◽  
pp. 7510
Author(s):  
Kishor Prasad Bhatta ◽  
Anisha Aryal ◽  
Himlal Baral ◽  
Sujan Khanal ◽  
Amul Kumar Acharya ◽  
...  

The high mountains stretch over 20.4% of Nepal’s land surface with diverse climatic conditions and associated vegetation types. An understanding of tree species and forest structural pattern variations across different climatic regions is crucial for mountain ecology. This study strived to carry out a comparative evaluation of species diversity, main stand variables, and canopy cover of forests with contrasting precipitation conditions in the Annapurna range. Firstly, climate data provided by CHELSA version 1.2, were used to identify distinct precipitation regimes. Lamjung and Mustang were selected as two contrasting precipitation regions, and have average annual precipitation of 2965 mm and 723 mm, respectively. Stratified random sampling was used to study 16 plots, each measuring 500 m2 and near the tree line at an elevation range of 3000 to 4000 m across different precipitation conditions. In total, 870 trees were identified and measured. Five hemispherical photos using a fisheye lens were taken in each plot for recording and analyzing canopy cover. Margalef’s index was used to measure species richness, while two diversity indices: the Shannon–Wiener Index and Simpson Index were used for species diversity. Dominant tree species in both study regions were identified through the Important Value Index (IVI). The Wilcoxon rank-sum test was employed to determine the differences in forest structure and composition variables between the two precipitation regimes. In total, 13 species were recorded with broadleaved species predominating in the high precipitation region and coniferous species in the low precipitation region. Higher species richness and species diversity were recorded in the low precipitation region, whereas the main stand variables: basal area and stem density were found to be higher in the high precipitation region. Overall, an inverse J-shaped diameter distribution was found in both precipitation regions signifying uneven-aged forest. A higher proportion of leaning and buttressed trees were recorded in the high precipitation region. However, similar forest canopy cover conditions (>90%) were observed in both study regions. The findings of this research provide a comprehensive narrative of tree species and forest structure across distinct precipitation regimes, which can be crucial to administrators and local people for the sustainable management of resources in this complex region.


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