Basal Area Values Research Articles

Structures of Forest Stands in Monospecific Reforestations Based on Tectona grandis Lf. (Verbenaceae) in the Sangoué Classified Forest in Côte d’Ivoire

Teak-based reforestation poses the challenge of sustainable development in terms of meeting economic, social and environmental needs. In order to meet the needs of populations for timber and contain anthropogenic pressures on flora, reforestation based on Tectona grandis is initiated in the Sangoué Classified Forest. Therefore, a diagnostic study is therefore essential to assess the effects of this practice on the environment. This study assessed the consequences of planting Tectona grandis on the conservation and restoration of the Sangoué classified forest. For this, the structural and floristic characteristics of teak stands at different stages of evolution were compared. The results showed that young plots have more plant species, are more diverse and more evenly distributed. Older plots have the highest densities and basal areas of stems, with an inverted J-shaped distribution. Young plots have the lowest densities and basal areas, as well as a more regular horizontal structure. The woody species introduced into reforestation are Tectona grandis, Gmelina arborea and Cedrela odorata. In the 33-year-old block, the total basal area value is 18.07 m² per hectare, then 13.72 m² per hectare in the 30-year-old block. As for the 25- and 28-year-old blocks, the basal area values per hectare are 12.61 m2 and 9.39 m2 respectively. Young plots promote natural regeneration and floristic diversity, while older plots present low floristic diversity with reduced structural balance. Introduced species have benefited more from teak planting than native ones. Teak planting may lead to profit, but it presents challenges for biodiversity. The impact of teak planting on the Sangoué classified forest differs depending on the stage of evolution of the stands. Therefore, it has advantages and disadvantages for forest restoration and conservation. The teak plantation needs to be adjusted to forest management.

Spatial-Temporal Dynamics of Water Resources in Seasonally Dry Tropical Forest: Causes and Vegetation Response

Seasonally Dry Tropical Forests (SDTFs) are situated in regions prone to significant water deficits. This study aimed to evaluate and quantify the dynamics and spatial patterns of vegetation and water bodies through the analysis of physical–hydrological indices for a remnant of FTSD between 2013 and 2021. Basal area, biomass, and tree number were monitored in 80 permanent plots located in two areas of an SDTF remnant with different usage histories. To assess vegetation and water resource conditions, geospatial parameters NDVI, NDWIveg, NDWI, and MNDWI were estimated for the period from 2013 to 2021. The observed patterns were evaluated by simple linear regression, principal component analysis (PCA), and principal component regression (PCR). Area 2 presented higher values of basal area, biomass, and number of trees. In area 1, there was an annual increase in basal area and biomass, even during drought years. The NDVI and NDWIveg indicated the vulnerability of vegetation to the effects of droughts, with higher values recorded in 2020. NDWI and MNDWI detected the water availability pattern in the study area. Physical–hydrological indices in the dynamics of tree vegetation in dry forests are influenced by various factors, including disturbances, soil characteristics, and precipitation patterns. However, their predictive capacity for basal area, biomass, and tree number is limited, highlighting the importance of future research incorporating seasonal variability and specific local conditions into their analyses.

Phytosociological study of a Grassland community of Baripada, Mayurbhanj district of Odisha, India: Conservation strategies for floristic diversity

A phytosociological study of the grassland community at Maharaja Purna Chandra Autonomous College (21 º 93’ N; 86 º 76' E) was conducted from July 2022 to July 2023. The study aimed to understand the floristic diversity and propose conservation strategies. A rigorous data collection methodology was implemented using 1 m × 1 m quadrat sampling, and the findings were analyzed and presented using a novel approach. Parameters such as occurrence (+) and non-occurrence (-) of species, frequency, density, abundance, basal area, basal cover, and Important Value Index (IVI) were recorded for 36 species (18 grasses and 18 non-grasses) throughout the research period. The study revealed that certain species, including Chrysopogon acciculatus and Evolvulus nummularius, exhibited high frequency, density, abundance and IVI throughout the research period. Conversely, Eragrostis unioloides and Sida cordifolia showed the lowest IVI during the study. Basal area and basal cover data indicated an inverse relationship between grasses and non-grasses. The total Relative Frequency (RF), Relative Density (RD), and Relative Dominance (RDo.) of the community were consistently around 100 for each month, and the total IVI values were approximately 300 each month. These results underscore the need for effective conservation strategies to preserve the unique floristic diversity of this grassland community. The remarkable phytosociological attributes of this experimental grassland community may be attributed to the topography, soil composition, and climatic conditions of the locality.

Waterline distance effects in the recovery of forest structure and soil organic matter 12 years after restoration

Efforts to restore tropical forests can result in large unpredictability in their trajectories, mainly due to spatial variation in abiotic conditions and plant resource availability. With the construction of a small hydroelectric power plant, a 70-ha forest restoration was conducted in 2008 within the boundaries of seasonal semideciduous forest in southeastern Brazil. This study described the spatial variation of the restored ecosystem after 12 years by simultaneously evaluating the direct influences of distance from the water body (waterline distance) and soil moisture, and the indirect influence of these factors mediated by the forest structure on accumulated litter and soil organic matter (SOM). These effects were estimated in the area under restoration and in forest remnants (considered as reference sites) (Model A), or in the area under restoration alone (Model B). Data on forest structure included density of individuals, total basal area, tree average diameter, average trunk volume index and stratification. Tree density decreased with increasing waterline distance both in the restoration area and in the forest remnants. Consequently, the sites closest to the reservoir formed denser and more stratified forests. Waterline distance and soil moisture content were correlated with each other, but each variable had independent effects of on the amount of litter and SOM. Wetter sites with denser and more stratified forest had greater amounts of accumulated litter and soil organic matter, but only in Model A, which included both the restored area and the forest remnants. In addition, higher basal area values contributed weakly to greater amounts of accumulated litter. Thus, our study suggests that the trajectory and speed of recovery of some ecosystem processes were determined by the waterline distance and soil moisture. Furthermore, the restoration implementation in the period of just 12 years was sufficient to detect the effect of these actions on the litter accumulation and a substantial increase in the amount of soil organic matter.

Effect of invasive species on forest composition in tropical dry forest: a case study of invasion by Gliricidia sepium

Ecological concerns caused by biological invasion have been considered an inevitable threat to global sustainability. The superior competitive ability of invasive plant species (IPS) has an impact on vegetation composition and loss of native flora. Recognising IPS at an early stage would significantly contribute to controlling invasive plants, protecting biodiversity and formulating appropriate strategies. Most of the studies available on invasive plants are descriptive and largely confined to non-woody species. The present study focused on the alien Gliricidia sepium, a tree species, to determine the invasive potential of its distribution in tropical dry deciduous forests of Central India. Forty square plots (25 × 25 m) were laid out at each uninvaded and invaded forest to enumerate phytosociological attributes to determine the impact of G. sepium on vegetation composition and community structure. Higher density (37.2 individuals ha−1), basal area (6.32 m2 ha−1) and importance value index (95.8) contributed by G. sepium clearly showed the suppression of seedlings, saplings and trees of native forest species at the invaded sites in terms of species richness, cover and other attributes as compared to at the uninvaded sites. Further, other invasive attributes such as higher seed production, dieback phenomenon, higher coppicing power and higher growth rate as observed during the study clearly affirmed the early speculation that the species might be invasive. The species has a strong potential to spread vigorously and may gradually become invasive throughout the country as already reported from various parts of India. In the present study area, G. sepium was introduced due to restoration and plantation programmes and our findings indicate its negative impact on the native vegetation. Thus, we strongly recommend the avoidance of this species for both plantation and restoration programmes, especially for Indian forests. The study helps in early recognition and rapid monitoring of G. sepium to control its spread throughout the country.

Growth, Yield, and Stem Quality of Tectona grandis Grown with Different Spacings at Longuza Forest Plantation, Tanzania

Spacing is a silvicultural practice that affects the growth of trees in forest plantations. However, the yield depends on growth, which is determined by spacing. In addition, spacing influences the quantity of the final crop available for harvesting, specifically in forest plantations for sawlog production. Spacing is also used as a management practice to control the quality of trees, as dense stands are expected to have trees with good stem quality. However, little has been done to address the effects of spacing on the growth, yield, and stem quality of Tectona grandis until final harvesting age. Teak plantations in Tanzania are grown at a rotation age of 20 years. Thus, this study aimed to assess the effect of spacing on the growth, yield, and stem quality of 24-year-old T. grandis in a Longuza Forest plantation in Muheza, Tanzania. Data were collected from a spacing trial using a randomized complete block design with three treatments: 2 m × 2 m, 3 × 3 m, and 4 m × 4 m, with three replications. The growth and yield parameters assessed were diameter at breast height (dbh) total tree height, and stem quality. Data were analyzed to obtain the basal area, volume, and mean annual increment. Statistical analysis was performed using analysis of variance (ANOVA), and multiple comparisons among treatment means were performed using Tukey's honest significant difference test (p-value = 0.05). The results showed that spacing did not significantly affect growth and yield parameters. The stem quality was significantly different in some treatments. The highest dbh and height growth were observed at 4 m× 4 m spacing. The highest values of basal area, volume, and mean annual increment were observed at a 3 m× 3 m spacing. Stem quality differed significantly between the 2 m× 2 m and 4 m× 4 m spacings. Because teak plantations in Tanzania are aimed at sawlog production, it is recommended to continue practising a spacing of 3 m× 3 m, which will ensure a higher mean annual increment with a higher volume at the stand level. In addition, a spacing of 3 m × 3 m ensured a higher percentage of trees with good stem quality.

Efeitos da densidade de plantio sobre características da madeira de sabiá

ABSTRACT This study aimed to evaluate the biomass yield, volume, and basic density of Mimosa caesalpiniifolia Benth. wood in response to planting densities in 13-year-old trees. The research was conducted in Mossoró-RN using a randomized block design with three replications. Plants obtained from seeds collected from the natural vegetation of the Caatinga in Mossoró-RN were subjected to densities of 800 (5.0 m x 2.5 m), 1600 (2.5 m x 2.5 m), 2000 (2.0 m x 2.5 m), and 4000 (1.0 m x 2.5 m) plants ha-1. The following characteristics were assessed: plant height, diameter at breast height, cross-sectional area, basal area, individual volume, stere volume, aboveground biomass, and basic wood density. The dendrometric variables showed a high correlation with planting density. For DBH and cross-sectional area, higher values were observed in the lowest planting densities. The highest values of basal area, volume (m3), stere volume, and dry biomass per hectare were found at the highest planting density. Biomass allocation showed the sequence stem>branches>leaves, regardless of the planting density evaluated. The higher densities resulted in a higher basic density of the wood. The higher planting densities proved advantageous 13 years after planting due to the higher production of dry biomass, volume (m3), and stere volume per hectare.

Mangrove condition at a marine conservation area at Moramo Bay, Sulawesi, Indonesia

Abstract. Oetama D, Hakim L, Lelono TD, Musa M. 2023. Mangrove condition at a marine conservation area at Moramo Bay, Sulawesi, Indonesia. Biodiversitas 24: 6536-6544. The mangrove ecosystem is one ecosystem that supports biodiversity at the Marine Conservation Area (MCA) in Moramo Bay, Southeast Sulawesi, Indonesia. The area of the mangrove ecosystem in Moramo Bay is approximately 1,933.09 hectares, with an MCA of 1,281.46 hectares. This ecosystem plays an important role in protecting the coastline from erosion due to the seawater filtration process in the bay. This study aims to provide information regarding the status of mangrove ecosystem in the MCA, including species, density, basal area, dominance, and canopy cover percentage, which was used to state the standard criteria for mangrove ecosystem damage. The methods involved a 10×10 m² transect and hemispherical photography using a fisheye lens with a 180° field of view. Seven species of mangrove were found in Moramo Bay MCA, including Bruguiera gymnorrhiza (L.) Lam. (dominating with a basal area value of 136,963.66), followed by Sonneratia alba Sm. (153,111.90), Rhizophora mucronata Lam. (113,708.04), Rhizophora stylosa Griffith (28,869.95), Xylocarpus moluccensis (Lam.) M.Roem. (9,326.59), Avicennia marina (Forssk.) Vierh. (3,419.46), and Rhizophora apiculata Blume with a basal area value of 1,690.11. The density of mangrove vegetation was in the criteria of rare to dense, with approximately 800-4,200 individuals per hectare. Furthermore, the mangrove ecosystem in the MCA was found to be damaged up to good condition, with canopy cover percentage values of 45.85%-98.88%. The condition of the mangrove ecosystem in Moramo Bay MCA preserves a basic deliberation for the Indonesian government for adaptive and sustainable management of conservation areas. Protection, preservation, and utilization of mangrove ecosystems should be maximized in all coastal areas to improve the quality of biodiversity.

Allied species with Dicksonia sellowiana Hook. in a High Montane Araucaria Forest Remnant, in Southern Brazil

The Araucaria Forest in highlands is an environment characteristic of regions with altitudes greater than 1200 above sea level, in southern Brazil. The species that occur in this place are adapted to conditions of low temperatures and high humidity, where the presence of Dicksonia sellowiana Hook., a tree-sized pteridophyte with expressive importance value in many remnants. This research aimed to identify the associations of this species in a remnant of Araucaria Forest in the mountain region of Santa Catarina. The site was inventoried with permanent plots of fixed area of 200 m², which were systematically and contiguously distributed in 3 transects following the slope gradient of the terrain (1411 to 1940 m). The surveys evaluated the scientific name, geographic coordinates and DBH, with an inclusion limit of 5 cm for each individual. Subsequently, 14 individuals of D. sellowiana were randomly selected and used as a reference to the center of the sampling units of Prodan method, than the six closest trees were measured, identified and measured the distance from the center of the unit sampling to the sixth tree (R6) to determine its area. As the measurements of the permanent plots contain the geographic coordinates of all trees, the selection of Prodan sampling units and the collection of data (R6, N.ha-1, G.ha-1) were performed using ArcGis Software. The average basal area value was 69.5 m².ha-1 and the average density was 1628 ind.ha-1, values compatible with those obtained in the permanent plots (69.4 m².ha-1 and 1630 ind.ha-1 respectively), obtaining sample sufficiency by the collector curve. Dicksonia sellowiana showed association with 14 species, being inserted in characteristic environments with less sun exposure, slopes and presence of watercourses, generating an environment with low floristic diversity, however, with a high degree of endemism in the Atlantic Forest.

Invasive Alien Plant Species Assessment in Semi-Arid Ecosystems: A Case Study from Southern Haryana, India

Forests of Southern Haryana are incredibly rich in medicinally important plant species but anthropogenic activities and invasive alien plant species are putting a huge stress on these forests. In order to comprehend the ecology of invasive alien plant species, the current study was carried out in the semi-arid forests of Southern Haryana districts, namely Charkhi Dadri and Mahendergarh. During the study, different analytical parameters were calculated such as density(D), basal area (B.A) and importance value index(IVI) along with different diversity indices such as Shannon-weiner index(H'), Simpson index(CD), Pielou index(d) and Margalef index(E). A total of 19 alien plants were recorded with family Asteraceae dominating with 5 species followed by family Solanaceae and Malvaceae. Some of the alien plants were turned out as deadly invasive such as Parthenium hysterophorus, Prosopis juliflora, Chenopodium murale and Croton bonplandianus with high value of IVI, affecting the survival and growth of important native plant species. Thus, the present study is carried out in the field of phytosociology in forests of Southern Haryana. Appropriate strategies must be implemented in this direction to retain the natural ecology of the area.

Comparative Study of the Diametric and Spatial Structures of Guarea cedrata (A. Chev.) Pellegr. (Meliaceae) in the Semi-Caducified Forests of the Central Basin Forest Massif (Tshopo Province, DRC, Congo Basin)

The comparative study of the diametric and spatial structures of Guarea cedrata (A. Chev.) Pellegr. was carried out in the semi-caducified forests of the Tshopo forest massif in the Democratic Republic of the Congo. For this study, two forest reserves were selected: the Yoko Forest Reserve and the Yangambi Biosphere Reserve, successively located in the Ubundu territory, 32 km southeast of Kisangani and in the Isangi territory, 100 km west of the same city. To conduct the present study, two devices of 200 hectares each, were installed, one in Yoko and the other in Yangambi where all the individuals of Guarea cedrata with dhp ≥ 10 cm were measured including their X, Y coordinates. A total of 177 individuals were inventoried within two reserves including 72 individuals, or 0.36 feet/ha in Yoko, and 105 individuals, or 0.525 feet/ha in Yangambi. The total basal area values are respectively 0.0695 m2/ha in Yoko and 0.1712 m2/ha in Yangambi. Both diametric structures are "stretched S" and the spatial distribution is aggregative in Yoko, while random in Yangambi. In general, perch positions and stands are independent from each other; however, there is some dependence at small scale of analysis within the two reserves

Woody Species Composition, Structure, and Diversity of Dindin Natural Forest, South East of Ethiopia

Information on species composition, structure, and diversity is essential to introduce and select different management activities to improve the forest productivity. Accordingly, species composition, structure, diversity, and regeneration status of trees were assessed in the Dindin natural forest. In this forest, trees or shrubs having ≥2.5 cm diameter at breast height and height >1.5 m were identified and measured in 35 quadrats of 20 m × 20 m. Regeneration status was assessed in 5 m × 5 m subplots that were laid within each main plot to sample seedling and sapling. Woody species diversity, density, basal area, and importance value index were calculated. To prioritize conservation efforts, the study utilized factors such as the importance value index, seedling and sapling densities, and population structure. A total of 42 woody tree species representing 30 families were recorded in the forest. The diversity and evenness of woody species in the Dindin forest were 2.66 and 0.70, respectively. Woody species density was 1403 individual ha−1, and the total basal area was 35.54 m2ha−1. About 480 seedlings per hectare were recorded in the Dindin forest. The research yielded practical insights into the dominance, population structure, importance value, and regeneration status of tree species. The analysis of population structure indicates that certain dominant species are experiencing inadequate regeneration. In addition, multiple nondominant shrubs and tree species within the forest are also at risk of extinction due to insufficient regeneration. Therefore, these important findings play a crucial role in the formulation and implementation of effective strategies to restore and rehabilitate the studied forest.

Forest activities drive diversity and structure in the tropical rainforest

AbstractLogging is widely known to be one of the major drivers of the loss of timber resources in tropical rainforests. In order to assess the contribution of this activity to biodiversity and carbon storage in Cameroon's Forest Management Units, this study was carried out in three Annual Allowable Cuts (AAC), of which two were logged, AAC 1‐1 (logged two years before), AAC 1‐2 (logged one year before) and one unlogged (AAC 1‐4). On each stand, 100 sampling plots of 20 m × 20 m were laid. The plot survey assessed the diversity indices, basal area, Aboveground Biomass, wood density, total height and importance value index of the tree species having ≥10 cm diameter at breast height. A total of 203 species belonging to 158 genera and 58 families were recorded. Piptadeniastrum africanum (7.21), Sterculia rhinopetala (23.35) and Ceiba pentandra (14.5) were the commonly traded species with the highest importance value index, respectively, for AAC 1‐1, 1‐2, and 1‐4. Non‐symmetric correspondence analysis (NSCA) revealed that the plots in AAC 1‐4 are more diverse, containing more biomass than those in AAC 1‐1 and 1‐2. Although selective logging has reduced species richness, it remains important to develop enrichment of species removed for ecosystem restoration.

Exploring the effects of various rotation lengths on the ecosystem services within a multiple-use management framework

Addressing the spatio-temporal dynamics of forest development under different management scenarios with varying rotation lengths is a challenge in forest management planning. This research aims to forecast forest development and assess the relative consequences of varying rotation lengths on several ecosystem services such as wood production, habitat for biodiversity, carbon sequestration, water provision, soil protection and cultural values. Forest development is simulated with the ETCAP model to examine the long-term effects of various rotation lengths with silvicultural prescriptions on the ecosystem services. Bürücek forest planning unit is used as a case study area with 10,711 ha forests in upper Mediterranean region of Turkey. Shorter rotation lengths are considered one of the main mitigation measures to climate changes in forestry; however, lead to the increased harvest level, net present value, ground water and soil loss, and reductions in the largest stand volume, understory, basal area, carbon storage and the cultural values with less regulated forest structure. The management scenarios with longer rotation lengths, however, have highlighted improvements in the carbon storage, larger standing volume, mean stand age, basal area and cultural values, and reductions in the mean harvest volume, net present value, ground water and soil loss due to larger-even distribution of tree sizes and stand development stages. An aspiration for a higher level of provisioning services for economic motivations may need to be discarded for the sake of enhancing the capacity of forest ecosystems to sequester more carbon and provide better habitat condition for biodiversity conservation with a careful design and selection of rotation lengths. Overall, the choice of optimal rotation length is highly dependent on a desired set of management objectives and target forest structure driven mostly by management interventions with the appropriate type and level of ecosystem services, provided that a thorough understanding of forest dynamics is achieved by considering both risks and uncertainties associated with natural disturbances and socio-economic conditions.

Vegetation diversity, structure, composition and carbon stock of community managed forests of Mid-hills, Nepal

Abstract. Joshi P, Joshi R, Sapkota RP, Panta M, Chand P. 2023. Vegetation diversity, structure, composition and carbon stock of community managed forests of Mid-hills Nepal. Asian J For 7: 29-36. Depending on management practices, forests can serve as both carbon sinks and sources. The goal of reducing carbon emissions and increasing the carbon sink is thought to be feasible if carbon reservoirs in current forests are protected and conserved. This study was objectively conducted to assess the vegetation diversity, structure, and carbon stock of the Mid-hills of Nepal. The study was undertaken in the Lanta Community Forest, Jajarkot District, Nepal, which has an extent of 38.65 hectares. Data for vegetation analysis and carbon stock assessment were collected using systematic random sampling using quadrats of 10×10 m with a total number of 35 quadrats. Within each quadrat, individual trees and bamboo were identified in the sites, and their height (m) and DBH (cm) were measured. Density, frequency, basal area, and Important Value Index (IVI) were calculated as structural parameters of vegetation. The Above-Ground Tree Biomass (AGTB) and Below-Ground Tree Biomass (BGTB) were calculated using an allometric equation based on tree diameter, height, and wood-specific gravity. The species diversity, species richness, and evenness were found to be 2.2, 2.35, and 0.83, respectively. A total of 14 tree species, with 723 individuals and one bamboo species were recorded. Rhododendron arboreum Sm. had the highest tree density with 211 trees/ha, while Tsuga dumosa (D.Don) Eichler had the highest IVI. Total wood volume, biomass, and total carbon stock were estimated at 15.37 m3 ha-1, 31.99 t ha-1, and 15.03 t ha-1, respectively. There was a strong negative correlation (r = -0.59) between R. arboreum and R. campanulatum D. Don and a strong positive correlation (r = +0.65) between Malus sikkimensis and Machilus species. For the preservation and sustainable management of community forests, information regarding the structure, composition, and dominance of tree species is provided by the study. The establishment of community forests is thus demonstrated in this article as a means of promoting the protection and preservation of regional biodiversity.

Plant Community Composition and Carbon Stocks of a Community Reserve Forest in North-East India

Anthropogenic activities are altering the structure and functioning of forests and their services to society. However, we know little about the degree to which such activities are changing the health of forests through edge effects in fragmented forests in different regions of the world. The present study was carried out in Minkong Community Reserve Forest of Nagaland (North-east India) with the aim to determine the effects of anthropogenic activities on floristic composition and diversity, population structure, and biomass and carbon (C) stocks in the core zone (CZ) and buffer zone (BZ) of the forest. We established 15 plots of 0.04 ha each in the two forest zones. We identified 31 trees, 18 shrubs, and 22 herbs in the CZ, and 22 trees, 25 shrubs, and 24 herbs in the BZ; tree species diversity was greater in the CZ whereas the diversity of shrubs and herbs was greater in the BZ. The values for tree density and basal area in the CZ and BZ were 303 and 197 individuals ha−1 and 32.6 and 22.2 m2 ha−1, respectively; in contrast, the shrub and herb density increased in the BZ (4470 and 50,200 individuals ha−1) compared to that of the CZ (2530 and 35,500 individuals ha−1). The total stand biomass (including that below-ground) was 327 Mg ha−1 in the CZ and 224 Mg ha−1 in the BZ. Similarly, the total ecosystem C stocks in the CZ and BZ were 224 Mg C ha−1 and 173 Mg C ha−1, indicating that the overall ecosystem C pool including soil in the CZ was approximately 30% greater than the BZ. These results show how fragmentation and anthropogenic disturbance can reduce forest diversity and C stocks and that community forest management can play a role in conserving biodiversity and act as an ecosystem management tool to mitigate climate change.

Floristic Composition, Diversity, and Vegetation Structure of Woody Species in Kahitassa Forest, Northwestern Ethiopia

Kahitassa forest is one of the State Forests of Ethiopia with great floral diversity. However, the forest is under threat due to selective cutting of important indigenous tree species and encroachment of the forest area for agricultural purpose. Therefore, the study was intended to explore the floristic composition, structure, and regeneration status of Kahitassa forest. Vegetation data were collected from June to November 2020 using systematic sampling technique from 6 parallel transect lines laid out 500 m apart each other. A total of 101 plots (20 × 20 m) were laid with 100 m apart along transect lines. Vegetation description parameters including Shannon–Weiner Index, evenness, density, DBH, basal area, frequency, and importance value indices (IVI) were computed to characterize both species diversity and vegetation structure. Hierarchical cluster analysis was used to identify plant communities using R (Version 3.1.2) software. A total of 46 woody plant species belonging to 45 genera and 36 families were identified in the forest. Fabaceae and Rosaceae were the dominant families both constituting 34.78% of the total species. The Shannon diversity index (H’) and evenness (E) values of the study area were 2.92 and 0.72, respectively, showing the healthy status of the forest. Five plant community types, namely, Croton macrostachyus–Embelia schemperi, Maytenus undata–Olea europaea subsp. cuspidata, Pavetta abyssinica–Bersama abyssinica, Peucadanum mattiroli, Albizia schimperiana, and Rubus apetalus–Phytolacca dodecandra were identified. The most dominant species as indicated by their important value index (lVI) were Pavetta abyssinica (34.08), Vachellia abyssinica (IVI = 25.13), and Albizia schimperiana (IVI = 21.45). Analyses of DBH revealed that the forest exhibits an inverted J-shape which is typical for selective cutting of multipurpose trees from the forest. Conservation approaches such as enrichment of selected species as well as in situ and ex situ conservation are needed for some plant species under threat.

Analysis of Mangrove Vegetation (Rhizophora sp.) and Vertical Spesies of Fauna in Induha Village, Latambaga District, Kolaka Regency

Indonesian territory is dominated by Rhizophora mangrove vegetation, but in the Kolaka area, especially Induha Village, there is no information about this type of mangrove, so research is needed. The purpose of this study is to determine the vegetation Rhizophora mangroves sp. and fauna vertically in the mangrove forest in Induha Village. The method used is the Point Centered Sampling Method (PCQM). The results obtained, there are 3 types of mangrove Rhizophora namely Rhizophora apiculata, Rhizophora mucronata, and Rhizophora stylosa, with the highest relative density being Rhizophora apiculata at the seedling level (42.13%), sapling (57.50%) and at the tree level (38.31%). The highest relative frequency was Rhizophora apiculata at seedling (35%), sapling (45%) and tree (34.5%) levels. Rhizophora apiculata has the highest relative basal area value at the seedling (50%), sapling (84.83%) and tree (52.34%) levels. The highest relative canopy was Rhizophora apiculata, at the sapling (57.2%) and tree (35.3%). The highest Important Value Index was Rhizophora apiculata, at the seedling level (1 25.3 %), sapling (24 4.5 %) and tree (1 56.1 %). The fauna vertically identified as many as 5 types of species including hermit crabs, sea slugs, caterpillars, weaver ants and black ants. The conclusion of this study is that there are 3 types of mangroves identified in the mangrove forest dominated by Rhizophora apiculata and 5 fauna species. Environmental factors that have been observed support the survival of mangrove species in Induha Village, both in zone 1 and in zone 2, especially the Rhizophora apiculata.

Soil seed bank composition and aboveground vegetation in dry Afromontane forest patches of Northwestern Ethiopia

The species composition in the aboveground vegetation and soil seed bank (SSB) were described for the dry Afromontane forest patches of Northwestern Ethiopia. Plots (30 × 30 m) were established to collect the vegetation and environmental data. Soil samples were collected for the soil bank study from the small plots measuring 10 cm × 10 cm from four soil layers. Shannon Weiner index and evenness were used to assess the species diversity and richness of the forest. Density, DBH, basal area, frequency, and importance value indices (IVI) of woody species were computed to characterize the vegetation structure of the forest. Results indicate the presence of 176 plant species belonging to 80 families. The Shannon diversity index and evenness values of the study area were 2.79 and 0.95, respectively were medium, compared to other dry Afromontane forests of Ethiopia. The total basal area and density of woody species were 51.42 m2 ha−1 and 2679.33 individual ha−1, respectively. The most dominant species as and indicated by their important value index (lVI) was Prunus africana (17.97). A total of 2133 seedlings belonging to 44 species and 27 families were identified from the soil seed bank, with a viable seed density of 4636.95seeds/m2. The species composition of the seed bank was dominated by 29 herb species (65.9%) compared to 2 tree species, which accounted for only 4.54% of the total number of species. The highest number of species density was recorded in the litter and the upper 3 cm layer of the soil and gradually decreased with increasing depth. The Similarity between soil seed bank species composition and aboveground vegetation was low and conclude that the regeneration potential of the forest from seed bank is limited. Redundancy analysis (RDA) showed that emerged seedlings from the soil seed bank were significantly influenced by elevation and soil cation exchange capacity. The natural regeneration process of soil seed bank should be assisted through transplanting indigenous tree species in to the forests to accelerate the restoration of the vegetation and conservation and sustainable utilization of the reaming of forest patches is a necessity.

Floristic composition, structure and regeneration status of woody plant species in Northwest Ethiopia

Most of the natural forests in Awi Zone of Northwest Ethiopia exist as patches due to increasing human disturbance. The Bradi forest in this zone was assessed for its floristic composition, structure and regeneration status of woody plant species to better understand the natural dynamics and suggest appropriate conservation strategies. A total of 60 quadrats (20mx20m) were established along transect lines running parallel to each other using systematic sampling for vegetation sampling. Height and diameter at breast height (DBH) were measured for those woody plant species >2 m in height and >2 cm in DBH. Seventy-one woody plant species that belong to 64 genera and 40 families were identified, of which 36 (50.7%), 13 (18.3%), 13 (18.3%) and 9 (12.7%) were trees, lianas, shrubs and trees/shrubs, respectively. A total of 1838 stems ha−1 with DBH >2 cm and height >2 m were recorded. Albizia shimperiana, Paveta abyssinica, Croton macrostachyus, Discopodium penninervium, Teclea nobilis were the most abundant and frequently-occurrring species in the forest. The forest had a Shannon species diversity index score of 3.84 and an evenness of 0.89. Furthermore, the forest had an average basal area of 90.03m2/ha. Woody species with high basal area value such as Ekebergia capensis, A. shimperiana, Prunus africana, and C. macrostachyus were found to have greater importance value index (IVI). According to the DBH and height class distribution, the forest had an inverted J-shaped distribution pattern. However, analysis of regeneration status at species level revealed that 27.5%, 10%, 40% and 22.5% of the woody plants had good, fair, poor regeneration and not regenerating, respectively. This calls for enrichment planting and area exclosures of the study forest.