scholarly journals Analysis of Structure and Diversity of the Kilengwe Forest in the Morogoro Region, Tanzania

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
David Sylvester Kacholi

This study investigates the structure, species composition, and diversity of a section of the Kilengwe Forest in Tanzania. In order to accomplish the proposed objectives, 18 plots of 20 m × 20 m were randomly established in the forest and the number of tree species in each plot was identified and counted. The most important families and species were determined using importance value indices at the respective taxonomic levels. Diversity was measured using the Shannon-Wiener and Fisher alpha diversity indices. A total of 276 stems/ha representing 93 species/ha within 26 families were documented from 0.72 ha. Fabaceae and Julbernadia globiflora were the dominant family and species, respectively. Seventy-eight percent of the total species were rare. The average basal area of the forest was 7.1 m2/ha. The Shannon-Wiener index (4.02) and Fisher’s alpha diversity (35.5) indicated high species diversity within the forest. The species-area and species-abundance curves revealed an escalating trend implying that more sampling efforts could result in a higher number of species existing in the forest. The size class distribution displayed a reverse J-shaped pattern; however, the larger size classes DBH >50 cm were not represented. The study suggests the necessity for anthropogenic disturbance control as this is the major source of forest degradation in the studied area.

REINWARDTIA ◽  
2018 ◽  
Vol 17 (2) ◽  
Author(s):  
Asep Sadili ◽  
Kuswata Kartawinata ◽  
Herwasono Soedjito ◽  
Edy Nasriadi Sambas

ADILI, A., KARTAWINATA, K., SOEDJITO, H. & SAMBAS, E. N. 2018. Tree species diversity in a pristine montane forest previously untouched by human activities in Foja Mountains, Papua, Indonesia. Reinwardtia 17(2): 133‒154. ‒‒ A study on structure and composition of the pristine montane forest previously untouched by human activities was conducted at the Foja Mountains in November 2008. We established a one-hectare plot divided into 100 subplots of 10 m × 10 m each. We enumerated all trees with DBH ≥ 10 cm which diameters were measured, heights were estimated and habitats were noted. We recorded 59 species, 42 genera and 27 families, comprising 693 trees with the total basal area (BA) of 41.35 m2/ha. The forest had lower species richness compared to those of lowland forests in Kalimantan, and Sumatra and montane forests in West Java. The Shannon-Wiener’s diversity index was 3.22. Nothofagus rubra (Importance Value, IV=47.89%) and Parinari corymbosa (IV=40.3%) were the dominant species, constituting the basis for designating the forest as the Nothofagus rubra - Parinari corymbosa association. To date, the dominance of N. rubra is unique to the Foja Mountains, as elsewhere in Papua the montane forests were dominated by N. pullei or other species. The species-area curve indicated a minimal area of 5000 m2. On the family level Fagaceae (IV=53.23%), Chrysobalanaceae (IV=40.53%) and Myristicaceae (IV=26.43%) were dominant. Verti-cally the forest consisted of four strata (A–D). In each stratum Nothofagus rubra, Platea latifolia, Parinari corymbosa and Myristica hollrungii were dominant. The diameter class distribution of Nothofagus rubra, Parinari corymbosa and Platea latifolia led us to assume that these species were regenerating well.


Diversity ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 32 ◽  
Author(s):  
Omar Cabrera ◽  
Ángel Benítez ◽  
Nixon Cumbicus ◽  
Carlos Naranjo ◽  
Pablo Ramón ◽  
...  

(1) Background: Neotropical montane forests represent one of the most diverse world ecosystems; however, they are also among the most threatened ones mostly due to deforestation. Our main goal is to classify and clarify the forest types based on the changes in basal area (BA), tree density, and species composition of montane forests in Southern Ecuador, and to determine the influence of critical environmental and geomorphological factors. (2) Methods: One hundred thirty-two temporary plots of 400 m2 were installed in homogeneous and well-conserved forest stands. We identified and measured all trees >10 cm diameter breast height (DBH). We modeled species diversity (Fisher’s alpha) change in relation to climatic, altitudinal, and geomorphological gradients using GLM and Kruskall-Wallis analyses. The change in composition was determined using cluster analyses (BIOENV analysis followed by a LINKTREE procedure). Non-metric multidimensional scaling (NMDS) was used to analyze changes across climatic and geomorphological gradients. Finally, we used a SIMPER analysis to identify the species that contributed most to the floristic dissimilarity among the identified altitudinal forests types. (3) Results: The floristic groups were determined by altitude, temperature, and isothermality, but also some geomorphological variables and lithology were used. Plots located in low hills have higher alpha diversity compared to the high hills and dissected mountains. (4) Conclusions: Altitude is the most important factor responsible for the division of structural and floristic groups. In addition, those plots located on the whitish tuff have higher alpha value diversity compared with plots in andesitic tuffs. Precipitation on the wettest quarter (>839 mm) and isothermality (>90.5) are the most relevant climatic factors driving the floristic classification.


2019 ◽  
Vol 11 (1) ◽  
pp. 132-138
Author(s):  
Sucipto Hariyanto ◽  
Akhmad Kharish Fahmi ◽  
Thin Soedarti ◽  
Emy Endah Suwarni

Ecotourism development program at Bama beaches area require baseline data of mangrove structure at Bama Resort and in the past two decades has been lost about 35% area of mangrove forest in Indonesia and in the worldThe aims of this study was to find structure, composition, distribution and zonation patterns of mangroves at Bama Resort Baluran Nasional Park. Ten belt-transects were laid perpendicular to the shoreline, using standard methods. Vegetation structure was determined using data collected on plant species diversity, density, basal area, and the number of each species of mangroves. Shannon Wiener index to calculated diversity, evennes and Simpson to calculated dominance index. The results show there are 2 families and 6 mangrove species occurring in the study areas that is Rhizophoraceae (Rhizophora stylosa, Rhizophora mucronata, Rhizophora apiculata, Bruguiera gymnorrhiza, and Ceriops tagal) and Araceae (Nypa fruticans). The highest importance value was R. apiculata (229.90%) for trees, R. apiculata (148.69%) for the sapling, and R. apiculata (244.83%) for the seedling. The diversity (H) and dominance index (C) values were moderate (1.79) and 0.521. The most dominant species was R. apiculata (C=0.487). The mangrove zonation pattern from coastline to the mainland was R. stylosa, R. mucronata, and R. apiculata, in the outer zone, respectively (zone directly adjacent to the sea); B. gymnorrhiza and C. tagal in the middle zone; and N. fruticans in the zone that adjacent to the mainland. The present study will aid in the conduct and preservation planning of mangrove forest especially at Bama coast and generally in the coastal areas of Indonesia.


2005 ◽  
Vol 137 (1) ◽  
pp. 120-127 ◽  
Author(s):  
Christopher M. Buddle ◽  
Julien Beguin ◽  
Elise Bolduc ◽  
Alida Mercado ◽  
Tara E. Sackett ◽  
...  

AbstractFor over three decades, the importance of taxon sampling curves for comparative biodiversity studies has been repeatedly stated. However, many entomologists (both within Canada and worldwide) continue to publish studies without standardizing their data to take sampling effort into account. We present a case study to illustrate the importance of such standardization, using the collection of spiders (Araneae) by pitfall traps as model data. Data were analyzed using rarefaction to represent one example of a taxon sampling curve, and by a variety of traditional diversity indices to describe alpha diversity. Raw species richness and single-index diversity measures (Shannon–Wiener, Simpson's, and Fisher's α) provided contradictory results. Rarefied species richness standardized to the number of individuals collected enabled more accurate comparisons of diversity and revealed when sampling was insufficient. Focusing on arthropods occurring in forested ecosystems, we also examined the use of taxon sampling curves in current literature by reviewing 133 published articles from 14 journals. Only 26% of the published articles in our review used a taxon sampling curve, and raw species richness and the Shannon–Wiener index of diversity were the most commonly used estimates. There is clearly a need to modify how alpha diversity is measured and compared for arthropod biodiversity studies. We recommend the abandonment of both raw species richness and single-index measures of diversity, and reiterate the need to use rarefaction or a related technique that allows for meaningful comparisons of species richness while taking into account sampling effort.


1999 ◽  
Vol 29 (7) ◽  
pp. 1073-1083 ◽  
Author(s):  
James H Miller ◽  
Robert S Boyd ◽  
M Boyd Edwards

This study tested for effects of site preparation herbicides applied at high labeled rates 11 years earlier on plant species richness, diversity, and stand structure and composition. Four study sites in three physiographic provinces were established in central Georgia in 1984. Six herbicide treatments were included on each site: hexazinone liquid, hexazinone pellets, glyphosate, triclopyr, picloram, and a mixture of dicamba and 2,4-dichlorophenoxyacetic acid (2,4-D). Herbicide and untreated plots were prescribed-burned and planted to loblolly pine (Pinus taeda L.). Eleven years after treatment, 177 total species were identified in these dense pine plantations; 99 species were forbs and grasses-grasslikes. Treated and check plots did not differ in species richness or diversity. Structurally, the total basal area of the tree canopy was not significantly altered, but the proportion of pine to hardwoods and shrub stem density were influenced by treatment. Latent effects were detected in the abundance and frequency of Pinus taeda, Prunus serotina Ehrh., Quercus stellata Wangenh., Diospyros virginiana L., Vaccinium stamineum L., Vitis rotundifolia Michx., and Lespedeza bicolor Turcz. Most are potential mast producers for wildlife. Herbicide site preparation had little influence on total species numbers or their diversity 11 years after treatment but affected composition by altering perennial species abundance.


Author(s):  
Antonio Mora-Santacruz ◽  
María Leonor Román-Miranda ◽  
Omar Nungaray-Villalobos ◽  
Gerardo Alberto González-Cueva

In order to study both diversity indices and structure of forests, which are an essential tool for decision-making in forest management, which show natural successional processes and effects for its management. So the objetive of this study was to evaluate structure and diversity of arboral species in a temperate forest of southern Jalisco state. Five permanent forestry research sites 50 x 50 (2.500 m2) were established, and a census of all tree species was carried out, with normal diameter greater than 7.5 cm. Each individual was measured: height and normal diameter, placing an aluminum plate for identification. We obtained the importance value index (IVI), indices of diversity, richness, and dasometric parameters. There were 17 species, 9 genera and 9 botanical families; the Fagaceae was dominant. Pinus douglasiana presented the highest IVI (57.93%); The Shannon index had a value of 2.0; the index of Margalef was 2.4; the forest has a density of 688 trees ha-1, being the most abundant Styrax ramirezii; Pinus herrerae obtained the highest values in basal area and volume with 30.77 m2 ha-1 and 357,325 m3 ha-1 respectively. The values of diversity are influenced by elements of the cloud forest


2019 ◽  
Vol 12 (1) ◽  
pp. 12-21 ◽  
Author(s):  
A.H. Toorani ◽  
H. Abbasipour ◽  
L. Dehghan-Dehnavi

Summary The white peach scale, Pseudaulacaspis pentagona Targioni-Tozzetti (Hemiptera: Diaspididae), is one of the most important and destructive polyphagous pests of the Rosaceae family trees. Population fluctuations and biodiversity of the hymenopteran parasitoid species associated with the pest were studied in six kiwi orchards in Iran, during one-year period. Parasitoid species abundance, species diversity indices and evenness indices were calculated. Most of the parasitoid species were dominant or eudominant. Based on the alpha diversity indices, the Najarkola region had high diversity and the Kharatkola region had low diversity. The Paeendasteh region (based on Simpson’s Diversity on Camargo evenness indices) and the Samnakola region (based on the modified Nee, and on Smith and Wilson evenness indices) were less uniform. Among the recorded parasitoids, Encarsia berlesei Howard (Hymenoptera: Aphelinidae), followed by Aphytis proclia Walker (Hymenoptera: Aphelinidae), had the highest population in all orchards.


2021 ◽  
Author(s):  
Admasu Moges ◽  
Abyot Dibaba

Abstract The main purpose of this study was to determine and compare the floristic composition and diversity indices of Washa and Borale Wetlands, located in Central Ethiopian. As revealed in the result, 74 species belonging to 26 families, and 57 genera were identified. Asteraceae and Poaceae were the most dominant families contributing 24.56% and 14.04% to the total genera, and 20.27% and 16.22% to the total species identified, respectively. Of the total, about 92% plant species were herbs, whereas 1% was climber, the least one. The alpha diversity of the Washa and Borale wetlands were 51 and 64, respectively. The average richness of the Washa and Borale wetlands were 12.3 ±0.91, and 15.35 ± 0.89, respectively. Likewise, the Shannon diversity (H’) and evenness (E) of Washa and Borale sites were 2.24 and 0.87, and 2.67 and 0.97 respectively. Accordingly, based on their average values, the diversity, evenness and richness indices were higher in Borale than Washa sites, and showed significance difference between the two wetlands (P < 0.05). Likewise, in both sites, especially in Borale, the majority of the species were native, annual and upland, implying the suitability of the wetlands to these native, but to annual and upland invaders due to the ecological and hydrological modifications of the wetlands, and competitive exclusion of the native aquatic plants by upland annual plants. Generally, many of the wetlands’ species were annual and upland invaders. Hence, in-situ and ex-situ strategic plans are required for restoring the wetlands via giving priority.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Amzad Basha Kolar ◽  
Palanivel. S, ◽  
M. Sheik Noor Mohamed ◽  
S. Sheik Mohamed ◽  
M. Shareef Khan ◽  
...  

Biodiversity plays a significant role in maintaining the ecosystem for their sustainable utilization. A preliminary survey was conducted to document the diversity and economic importance of the angiosperms around the Medavakkam Lake, Chengalpattu district, Tamil Nadu. The study area act as a seed bank for native species and provide suitable conditions to endemic and certain endangered species. Diversity indices of the study area was found significant, in which the species abundance, richness and evenness were found. A total of 71 species belonging to 36 families of angiosperms were documented. Among which the Dicotyledons plants were 87.32% and monocotyledon plants were 12.67% of total flora reported. The study area was dominated by the family fabaceae (14.1%) with ten species. Habit wise classification of plants reveal that trees are predominant with 32%, followed by hers (25%), Shrubs (21%), Climbers (13%), undershrubs (6%) and grasses (3%). The Simpson Diversity Index, Shannon Wiener Index and evenness index of the study area is 0.777, 1.5634 and 0.8725 respectively. These plants was found with enormous benefits to the mankind such as medicinal, edible, timber, ornamental, oil and other sources. This investigation divulges that the Medavakkam Lake has substantial angiosperm diversity served as major source for native plants having greater economic importance.


2015 ◽  
Vol 33 (1) ◽  
pp. 64-73 ◽  
Author(s):  
Javier Ramírez S. ◽  
Verónica Hoyos C. ◽  
Guido Plaza T.

<p>Phytosociological studies allow for the characterization and descriptive analysis of weed communities in crops. This study aimed to characterize the weed communities associated with weed crops in the “Centro, Meseta, and Norte” zones of the Tolima Department. The study was conducted in 96 commercial lots, in which a 1 ha area was marked off for the sampling. The development stage, density and cover of the weeds were evaluated. The importance value index, the alpha diversity indices of Shannon-Wiener, Simpson and uniformity as well as the similarity indices of Jaccard, Sorensen and Steinhaus were calculated. For the entire department, 42 weed species were identified, with <em>Echinochloa colona</em> being the principal one in all of the zones. In the Centro zone, 27 species were identified; in the Meseta zone, 31 species were identified; and, in the Norte zone, 38 species were identified. The alpha indices demonstrated that the Meseta zone was the most diverse. The Jaccard and Sorensen indices showed dissimilarity in the weed community for all of the comparisons of the zones. The Steinhaus coefficient registered the highest similarity intensity between the Centro and Norte zones. </p>


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