Total Basal Area Research Articles

Denser forests across the USA experience more damage from insects and pathogens

Forests across much of the United States are becoming denser. Trees growing in denser stands experience more competition for essential resources, which can make them more vulnerable to disturbances. Forest density can be expressed in terms of basal area, a metric that has been used to assess vulnerability of some forests to damage by certain insects or pathogens. A raster map of total tree basal area (TBA) for the conterminous United States was compared with annual (2000–2019) survey maps of forest damage due to insects and pathogens. Across each of four regions, median TBA was significantly higher within forest areas defoliated or killed by insects or pathogens than in areas without recorded damage. Therefore, TBA may serve as a regional-scale indicator of forest health and a first filter for identifying areas that merit finer-scale analysis of forest conditions.

Landsat data respond to variations in the structure of Caatinga plant communities along a successional gradient.

Plant community succession is generally approached with phytosociological methods, but field surveys are time-consuming, expensive, and limited to several of sites. Remote sensing offers an efficient and economical way to analyze vegetation on large extensions and in inaccessible areas. Most studies addressing remote sensing and tree community succession refer to forest physiognomies. We investigated whether structural changes that occur in non-forest physiognomies are identified by multispectral sensor images (OLI-Landsat). Thirteen 0.1-ha plots were set up in Caatinga fragments aging 10-15, 20-25, 30-35, 40-45 and >50 years to calculate the total density of individuals (TD), mean canopy height (H), total basal area (G) and total aboveground biomass (AGB). We performed correlation analyses between these structural descriptors and eight remote sensing variables (reflectance data and spectral indices) obtained from Landsat images at the end of the rainy season and during the dry season. Blue and short-wave infrared reflectances were negatively correlated with mean height, basal area and biomass, regardless of the analyzed scene (coefficients between -0.58 and -0.79). The litter layer (a non-photosynthetic vegetation component) and the soil exposure are important factors influencing the spectral data.

ASSESSMENT OF TREE SPECIES DENSITY AND STRUCTURE IN GANGUME FOREST RESERVE BALI LOCAL GOVERNMENT AREA TARABA STATE, NIGERIA

Taraba State is one of the states in Nigeria that produce high quality timber. A study to determine the density and stands structure of Gangume Forest Reserve was carried out in Bali Local Government Area of Taraba State, Nigeria. Twenty hectare plots were lay out in the forest and each plot was re-demarcated into four equal sizes of 50m x 50m and one was randomly selected for enumeration. A total of 592 tree species were enumerated belonging to 17 families. The data were analyzed using frequency, percentage, density, basal area, diameter (dbh), and total height of the tree species. The result of the study revealed that the average density was 118 trees/ha, total basal area was 18.2918m2 with an average of 0.91459m2/ha and the diameter distribution revealed that majority (152) 26.0% of the trees falls into diameter class of 20-29cm, followed by 10-19cm (102) 17-2%, and 30-39cm (101) 17.0%. The density was more in the lower DBH from 10cm to 39cm accounting for a total of 380 (64.1) trees in the forest. Four stratum of tree species population structures were identified with the intermediate strata with the highest (201) 33.9% population of trees, followed by the co-dominant with (199) 33.6%, ground floor with (192) 32.4% and the dominant/emergent with only (10) 1.6% population of trees. There is high human activities in the forest despite the fact that the forest has good reproduction and ability of regeneration. The forest should be left undisturbed to regenerate naturally.

The Nauclea, Tristaniopsis, and Terminalia forests: Exploring the lesser-known biotopes of Agusan Marsh, Philippines

The peat swamp forest of Agusan Marsh is characterized by the dominance of a unique and conspicuous assemblage of tree species across different habitat types. Understanding the species richness, diversity, structural patterns, and distribution of these types of forests is crucial for maintaining ecosystem stability and conservation. This study describes three less-explored biotopes dominated by Bangkal (Nauclea orientalis L.), Dangilas (Tristaniopsis decorticata Merr.), and Lanipau (Terminalia copelandii Elmer), using a purposive random sampling method. Across the three sites, 22 tree species, belonging to 17 families and 21 genera, were recorded. Tree density was recorded as the maximum at the Tristaniopsis biotope (650 individuals ha-1) and the minimum at the Terminalia biotope (367 individuals ha-1). The maximum total basal area (162.93 m2 ha-1) was re-recorded in the Tristaniopsis biotope and the minimum area in the Nauclea biotope stand (17.3 m2 ha-1). The ANOVA results for stand DBH, tree density, species richness, species diversity, and species evenness varied significantly among biotope types. The Tristaniopsis biotope had the highest species richness and diversity among the three sites. All stands exhibited a high community dependence on forest resources, which may have increased the vulnerability of the forest to human interference, thus necessitating immediate attention to conservation. Site-specific management and conservation measures are proposed to provide opportunities for sustainable forest management.

A Comparative Study on Community Structure and Regeneration Status of Tree Species in Urban Forests of Delhi, India

‘New Delhi’ capital of India is under immense pressure to sustain increasing population and to cope up with urbanization. It has urban forests or ridges, which aids the Delhi’s healthy lifestyle by balancing ecosystem. To assess the forest health the species composition, density, basal area, IVI, diversity indices, regeneration status of tree species were evaluated. Three sites namely Kamla Nehru Ridge (KR), Central Ridge (CR) and Southern Ridge (SR) were selected. A total of 51 tree species belonging to 21 families were reported. Species richness varied for trees (20-37), saplings (5-20) and seedlings (5-11). Densities ranged between (517-1043 Individuals/ha) for trees, saplings (133-470 Individuals/ha) and seedlings (53-273 Individuals/ha) respectively. Species diversity ranged between for trees (2.3-3.3), saplings (1.4-2.2) and seedlings (1.5-2.1). Total basal area varied from 4.87 to 22.94 m2/ha (trees), 0.26 to 0.49 m2/ha (saplings) and 0.17 to 0.02 m2/ha (seedlings). Maximum species (20-70%) showed ‘no’ regeneration whereas, (30- 50%) showed ‘poor’ regeneration and only Acacia leucocephala showed ‘fair’ regeneration in SR. It was observed that Prosopis juliflora was the dominant species in all three sites; it is an exotic species which hinders the understory growth. All over regeneration status of Delhi’s urban forest was found ‘poor’, which is a matter of concern. For balance environment and for proper inflow of ecosystem services provided by urban forest to sustain healthy lifestyle in city, it is necessary to implement proper strategies for conservation and maintenance of these forests.

Tree Species Diversity and Regenerating Potential along Disturbance Gradient in Chandragiri Hill, Kathmandu, Central Nepal

Tress species regeneration is greatly influenced by climatic, topographic, and anthropogenic activities. Present study was designed to examine the tree species diversity and their regeneration patterns along the anthropogenic disturbance gradient in the temperate forest of Chandragiri Hill, Central Nepal. Data were obtained from 90 sample plots ranging between 1560 to 2290 m asl after randomly sampling along three disturbance classes classified based on canopy coverage and degrees of disturbance activities in 2021. Circumference at breast height (1.37 m height above the ground) of each tree individual was measured and classified into tree, sapling, and seedling. A total of 47 tree species belonging to 42 genera and 26 families were obtained by this study. The highest species richness for seedlings and saplings was obtained in severely disturbed areas and tree species richness in the moderately disturbed area. The tree stands density varied between 350 to 1017 individuals ha-1 with the total basal area between 12.7 to 72.78 m2 ha-1 with the least value in a highly disturbed area and highest in the least disturbed area. The seedling and sapling densities were found increased from lower to more disturbed forests indicating that the forest fragmentation negatively affected the regeneration. The highest values of the Shannon Weiner index, Pielou Index, and the lowest value of the Simpson index were observed at moderate disturbance areas. About 36 to 60% of species were found regenerating in the less disturbed and moderately disturbed forests and no regeneration in severely disturbed areas. Elevation, canopy cover, landslide, and slopes were found to be the most influential variables in forest regeneration as significantly represented by CCA1. The present study has found a moderate level of disturbance to become beneficial for better regeneration of tree species. So, the reduction of excessive disturbance from local people would be a better option for the adequate regeneration of tree species.

Long-term recovery of Mexican spotted owl nesting habitat after fire in the Lincoln National Forest, New Mexico

BackgroundDry mixed-conifer forests of the southwestern United States are experiencing rapid, anthropogenically driven fire regime change. Prior to the Euro-American settlement, most of these forests experienced frequent surface fires but are now vulnerable to uncharacteristically large, high-severity fires. Fire directly influences the structure and composition of these forests and, in turn, the wildlife that inhabit them. Changing fire regimes result in a certain decline of some species and uncertain consequences for others. The Mexican spotted owl (Strix occidentalis lucida) is a federally listed threatened species of particular note in southwestern mixed-conifer forests. High-severity fire is cited as the owl’s primary threat in the revised species recovery plan, but uncertainties surround the impacts of high-severity fire on the habitat of the threatened owl, particularly across a timeframe longer than a few years. Our objective was to explore the long-term (100-year) effects of fire severity on elements of forest structure vital for Mexican spotted owl nesting. We quantified structural attributes for nest/roost habitat across mixed-conifer forests that burned at varying severity levels and time periods in the last century. We then examined the drivers of structural attributes by detecting statistical differences between severity classes and time periods through permutational multivariate analysis of variance.ResultsHigh-severity fire has the strongest deleterious impact on elements of forest structure (total basal area, percent medium tree basal area, percent large tree basal area, large tree density, and canopy cover) vital to Mexican spotted owl nesting, and although the structural differences between severity classes diminish with time, it took ≥ 80–100 years to reach the structural conditions desired for Mexican spotted owl nesting after stand-replacing fires. The most important attribute measured, canopy cover, required 90–100 years after high-severity fires to reach levels most suitable for Mexican spotted owls in the Lincoln National Forest.ConclusionsAs fires increase in frequency, severity, and size compared to the last century, the Lincoln National Forest is projected to face an overall decrease in the structural conditions needed for Mexican spotted owl nesting habitat in this region. Short intervals between uncharacteristically high-severity fires in particular pose an imminent threat to nesting habitat.

Carbon Stock and Carbon Dioxide Sequestration Potential in a Multi-species Forestry Plot of the Kagyu Nalanda Monastery, Bylakuppe, Mysore District, Karnataka, India

In the Kagyu Nalanda Monastery in Bylakuppe, Karnataka, India, during 2010-2011 has established the multi-species forestry plots in the degraded land of the monastery and nurtured them. In one of these plots (2.5 ha in size) aboveground biomass, carbon stock and the potential of carbon dioxide sequestration in the aboveground biomass were assessed. In the study plot, 927 trees belonging to 45 species were recorded. The Gini Index obtained for different species indicated that within a species the inequality is low for tree height when compared to that for tree basal area. The estimated total basal area and total tree volume in the study plot is 33.34 m 2 and 315.73 m 3 respectively. The total aboveground biomass for the plot was 326.39 tonnes with the total carbon stock of 163.18 tonnes. A positive correlation was observed between the carbon stock and total tree volume of the top five species ( Cassia fistula , Swietenia macrophylla, Mangifera indica , Moringa oleifera and Spathodea campanulata), which contributed predominantly (54%) of the total carbon stock (r=0.812, p<0.05). The study plot sequestrated 598.13 tonnes of carbon dioxide with mean annual rate of 59.81 tonnes. the potential annual economic value of carbon dioxide sequestrated in the aboveground biomass of tree community in the study area ranges from US$ 239.3 to 2,990.7 (Indian Rupees 17,872 to 2,23,402; US$ 1= Rs.74.7). The scope for selling the carbon credits generated in this multi-species forestry plot to buyers to support further environmental priorities are discussed.

Species Composition, Structure, and Regeneration Status of Woody Plants and Anthropogenic Disturbances in Zijje Maryam Church Forest, Ethiopia.

Our current study was conducted in Zijje Maryam Church Forest, Ethiopia, to explore woody species composition, structure, regeneration status, and anthropogenic disturbances inside the sacred groves. The aforementioned information for adequate conservation and management of the church forest is not well documented. Fifteen main quadrats each having an area of 625 m2 (25 m × 25 m) were used for vegetation and disturbance data collection. Determination of the sampled quadrats was based on the principle that minimum quadrats give the smallest possible area in which all species occurring in the church forest are present. All woody species with a diameter at breast height (DBH) ≥ 2.5 cm within the quadrat were identified, counted, and their height and DBH data were recorded. The criterion to start at DBH ≥ 2.5 cm was to exclude seedlings having DBH < 2.5 cm and height ≤0.6 m. Sapling and seedling data were collected using 45 saplings and 45 seedling quadrat that measured 4 m2 and 1 m2, respectively. Vegetation data analysis and ANOVA were used for statistical comparison. A total of 48 woody plant species belonging to 46 genera and 36 families were identified. Fabaceae was the dominant family containing 5 species followed by Rosaceae with 3 species. Total basal area of the church forest was 83.03 m2 ha-1. The density of seedlings, saplings, and matured woody species stem ha-1 were 15555, 3833, and 865, respectively. Talking these densities, the regeneration status of the forest was good. The Shannon diversity and evenness of woody plant species in the forest was high, 3.29 and 0.85, respectively. Juniperus procera 27.67 (9.22%) and Olea europaea were species with the highest IVI. Nearly, 22% of areas of the forest get disturbed and higher anthropogenic disturbances occurred near the edge of the forest. Gathering, clearing, and grazing are the major human disturbances that stakeholders need to tackle for conservation. Zijje Maryam Church Forest has heterogeneous species composition with varied seedlings and saplings. Therefore, local conservation policies recommended not only protect large forests, but also the small and valuable forests service to the needs of local people.

Inventory of close-to-nature forest stands using terrestrial mobile laser scanning

• Hand-held mobile LiDAR data of a close-to-nature forest in the leaf-on season. • Fully automatic processing using modified mean-shift and RANSAC algorithms. • 96.5 % detection and 3.5 cm DBH RMSE for trees with DBHs from 4 to 80 cm. • A comparison of different levels of low-intensity filtering is performed. • A walking trajectory consisting of concentric circles is recommended. In this work, we evaluated mobile laser scanning (MLS) technology for the acquisition of individual tree data in a close-to-natural forest structure. The data was collected during the leaf-on period in a single-tree selection forest stand. Individual tree positions and diameters at breast height (DBHs) were acquired in an automatic process. MLS data was collected on 1000 m 2 circular inventory plots. We compared three trajectories consisting of the plot perimeter and 1), two perpendicular lines, 2) an additional concentric circle, and 3) four parallel lines. We compared two algorithms for tree segmentation: 1) a density-based approach and 2) a modified mean-shift algorithm. The diameters were estimated using a modified random sample consensus (RANSAC) algorithm. We tested a series of intensity thresholds for filtering returns from green vegetation. We achieved the best results with an intensity threshold of 0.7 quantile of point intensities, and mean-shift segmentation, resulting in the correct identification of trees representing 96.5 % of basal area and an overestimation of 6.8 % of the total basal area. The algorithm omitted mainly small trees and trees at close distances. False detections mainly comprised unvalidated detections of real trees that were not field-measured as their diameter did not exceed the registration limit, or were caused by point structures representing leaves and understory vegetation. Diameters were estimated with a mean error of 0.03 cm and a root mean square error of 3.5 cm. A joinpoint regression model demonstrated that for small trees (<9 cm) the diameters were generally overestimated. Diameters above 12 cm were underestimated consistently by 1 cm. The trajectory comprising two concentric circles was the most efficient.

Lianas rapidly colonize early stages of tropical forests, presumably through leaf trait diversification

AbstractQuestionsEcological succession is the process during which ecosystems recover after disturbances. Studies investigating community reassembly during tropical forest succession have rarely compared lianas to trees. We addressed two questions: (1) how do changes in stem density, total basal area and species richness of lianas and trees compare throughout a secondary succession, and to what extent does the relative basal area of lianas change along a secondary succession; and (2) how do the successional trajectories of functional community trait values of lianas and trees compare?LocationYoko forest reserve, central Congo basin.MethodsUsing univariate Bayesian modeling techniques, we analyzed differences in successional pathways between lianas and trees in terms of community structure, and functional assembly in a replicated chronosequence spanning from young to old‐growth forests.ResultsWe found divergent structural trajectories between lianas and trees along the forest chronosequence. The stem density of lianas peaked at the intermediate stage, while that of trees almost linearly decreased from early to late stages of succession. The basal area of lianas increased at a higher rate than that of trees, which translated into a marginal increase of liana relative basal area over succession. On the contrary, we observed a lower rate of increase in species richness for lianas than trees over succession. We found a progressive convergence in the responses of lianas and trees to changes with succession in terms of specific leaf area and leaf nitrogen content, but a diverging response in terms of leaf phosphorus content. These functional composition patterns most probably resulted from environmental filtering, induced by a change from nitrogen to phosphorus limitation as the succession progressed to a mature forest.ConclusionsThese findings underscore the rapid colonization of tropical forests by lianas after agricultural abandonment, presumably by deploying a more diverse leaf economic spectrum early in succession.

Investigation of Woody Species Structure and Regeneration Status in the Central Rift Valley, Sidama Regional State, Ethiopia

Protected areas are the most commonly used tool for in situ conservation of biodiversity. Selective removal of species proposed by the local communities living surrounding the national park and grazing pressure negatively affect the composition, structure, and regeneration of woody species. Assessment of vegetation structure and regeneration status of woody species is essential for orienting management activities. The purpose of this study was to investigate the floristic composition, population structure, and regeneration status of woody species in the Loka Abaya National Park, to design conservation strategies. A total of 99, 20 m × 20 m quadrats were systematically laid along an established line transect to collect a list of woody species, abundance, height, and diameter at breast height (DBH), while five 3 m × 3 m subquadrats within the main quadrats were established to assess the regeneration status of woody species. In each quadrat, all woody species were identified, counted, and recorded. In each quadrat, all tree and shrub species higher than ≥2 m in height and ≥2 cm in diameter at breast height were measured by a calibrated wooden stick and by a caliper, respectively. Density, frequency, basal area, importance value index (IVI), height, and diameter at breast height (DBH) were used for description of vegetation structure, while the density of mature trees, saplings, and seedlings was used for assessment of regeneration status of woody species. A total of 101 woody plant species representing 40 families in 69 genera were collected, identified, and documented. Fabaceae was the most diverse family representing 16 (15.84%) species, followed by Euphorbiaceae 9 species (8.91%) and Anacardiaceae with 6 species (5.94%). Four families including Combretaceae, Moraceae, Olacaceae, and Tiliaceae were represented by 4 species each. 4 families were also represented by 3 species each, 12 families were represented by two species each, and 18 families were represented by one species. The density of trees was 831.31 individuals ha−1, while the total basal area was 73.18 m2·ha−1. D. angustifolia, C. molle, E. schimperi, R. natalensis, O. europaea L. subsp. cuspidataD. cinerea, A. brevispica, I. mitis, and E. tirucalli were ecologically important woody species. The majority (75%) of woody plant species had a less than 5% importance value index (IVI). The diameter class distribution of selected tree species demonstrated various patterns of population structure, implying the existence of different population dynamics among ecologically important tree species. The regeneration assessment results demonstrate that 32.35% had poor regeneration, 19.12% had good regeneration, 16.17% had fair regeneration, 8.82% lacked regeneration, and 14.08% appeared as newly regenerated species in the national park. The majority of woody species had a small population size, and some of them were found in specific habitats which need attention for conservation, and those woody species lack regeneration study soil seed bank and propagation methods for sustainable conservation.

Stem Growth of Horse Chestnut (Aesculus hippocastanum L.) under a Warming Climate—Tree Age Matters

This research provides new information about the effect of drought on horse chestnut growth (Aesculus hippocastanum L.) in different ages. Global climatic scenarios predict a higher frequency of heatwaves and drought periods; however, investigations into the growth reaction of horse chestnut to drought are completely lacking. Approximately 50-year-old solitary, 100-year-old solitary, and 100-year-old canopy horse chestnut trees in a floodplain area were investigated. Growth reactions measured using automated dendrometers with respect to meteorological variables and water table depth were investigated during the years 2019–2021. Cambial activity was shown to be driven by tree age, as younger trees had higher stem radial increment rates. Both mature tree groups suffered from a low depth of water level and from higher sensitivity to meteorological variables, as growth was limited when mean daily vapor pressure deficit (VPD) exceeded 600 Pa. Together with a lower probability of growing days and a shorter growing season (GS) with earlier cessation of growth resulted in a lower total year radial increment (GRO) and basal area increment (BAI) when compared to younger trees. The young trees also exhibited lower tree-water-deficit-induced stem shrinkage (TWD) across all the studied years. Overall, horse chestnut trees in this floodplain area could be endangered by the decreasing level of soil water, with a greater age exacerbating the effects of drought. The year water deficit exceeded −340 mm in this locality every year, which has to be compensated for by regular flooding.

An investigation into lidar scan angle impacts on stand attribute predictions in different forest environments

As studies have underlined the sensitivity of lidar metrics to scan angles, the objective of this study was twofold. Firstly, we further investigated the influence of lidar scan angle on the ABA predictions of stand attributes of riparian (29 field plots), broadleaf (42 field plots), coniferous (31 field plots) and mixed (45 field plots) forest types in France. Secondly, we evaluated the potential of voxelisation approaches to normalise scan angle effects in lidar metrics and mitigate scan angle effects in ABA models. To achieve these objectives, we first selected a model based on four lidar metrics with different sensitivities to lidar scan angle, i.e. mean and variance of canopy height values, gap-fraction, and coefficient of variation of plant area density (PAD) profile. For each plot, we considered the point cloud scanned from one flight line independently and characterised each resulting point cloud by the mean scan angle (MSA) and classified them into one of three classes: A (0° <=MSA < 10°), B (10°<=MSA < 20°) or C (20°<=MSA < 30°). An experimental setup involving nine scenarios was conceived to study the impact of the number of flight lines (scenarios fl1, fl2 and fl3) and predominant scan angle (scenarios A, B or C) or combination of scan angle directions (scenarios A and B, or A and C, or B and C), on area-based approach (ABA) models. We built ABA models for the same forest plots for 5000 resampled datasets in each scenario to predict three forest attributes, i.e., stem and total volume (Vst and Vtot) and basal area (BA). Three goodness-of-fit criteria were computed for each model (coefficient of determination (R2), relative root mean square error (rRMSE) and mean percentage error (MPE). We compared the distributions of the goodness-of-fit criteria between scenarios to assess the behaviour of the predictive models when: 1) the number of flight lines (i.e., scan angles) increases (fl1, fl2 or fl3); 2) lidar datasets comprise specific scan angle (A, B or C) or combination of scan angles (AB, AC or BC); 3) voxelisation is used to compute Pf and CVPAD. The results show that models built with point clouds scanned from multiple flight lines were more robust, with a lower standard deviation of their goodness-of-fit criteria. On average, across all forest types, compared to fl1, the standard deviations of R2 distributions were lower for fl2 and fl3 by 42 % and 77 %, respectively. We also observed that a dataset with a predominantly nadir configuration (i.e., scenario A) did not always result in better predictions (mean R2 higher by 0.08, 0.07, 0.04 for scenario B for broadleaf, coniferous and mixed, respectively). For a set ofcalibration plots, the resulting forest attribute models depend on the acquisition geometry over the plots, as observed in this study, which could result in unreliable wall-to-wall predictions. The risk is particularly high in acquisitions with low overlapping rates, with many areas covered by only one flight line. Using voxel-based Pf and CVPAD together with the mean and variance of heights helped to mitigate the impacts of changes in scan angles by a) increasing the means of the distributions, thereby improving the accuracy of predictions, or b) reducing the standard deviations, thereby increasing prediction precision, or c) both of the above.

Evaluation of Trees Species Diversity, Abundance and Soil Physicochemical Properties of Ukpon River Forest Reserves, Cross River, Nigeria

Current status of species diversity, composition and abundance provides guidance for their management and assessment of their ecological usefulness. In this study trees species diversity, abundance and soil properties of Ukpon River Forest Reserve was assessed. Line transect method was using to establish 4 sample plots of 50 x 50 m. Data on vegetation were collected using the appropriate tool and soil samples from the plot were collected with the aid of soil auger. Tree species composition, abundance and diversity indices were estimated using the appropriate formulae and soil samples analyzed following standard methods. A total of 194 individuals in 60 species belonging to 26 families were encountered in the study area. The dominant families are Leguminaceae, Moraceae, Fabaceae, Burseraceae, Apocynaceae, Calsalpinaceace and Euphorbiaceae. The total basal area estimated for tree species was 147.615m2 with Bombax bounpozen having the highest of 11.09m2 and relative dominance (RDo) of 7.51% while Piptadeniastrum africana has the highest relative density (RD) of 7.73% and importance value index (IMI) of 15.63%. Based on their relative density, 68.34% of the trees were Rare, 18.33% Threatened or Endangered, 5% Abundant/ Occasional and 3.33% Frequent. The study had a high Shannon – Weiner index value of 3.04 and Margalef richness of 20.67 and low dominance index of 0.06. The soil properties such as Clay, Organic matter, Phosphorus, Calcium, Cation Exchangeable capacity and Base Saturation were high. The pH value of 5.77 shows the soil were moderately acidic. These properties have been shown to improve soil fertility status and moisture content needed plant growth. Although the tree species diversity in the study area was high, some species appears to have been threatened while majority were rare, sustainable conservation effort should be geared towards ensuring their continuous existence.

Increasing liana biomass and carbon stocks in tropical dry evergreen forests of southern India

Tropical forests act as a great carbon reservoir covering about 30% of the global carbon content, however, structural alteration of these forests caused by forest disturbances adversely affects the carbon cycle. One such structural change happening in these tropical forests is the increasing dominance of lianas (woody climbers). Among various tropical forest types, lianas are an integral constituent of the tropical dry evergreen forests (TDEFs) found in peninsular India. A re-inventory of lianas was carried out to observe temporal changes in basal area and carbon stock in two 1-ha permanent plots of two disturbed tropical dry evergreen forest sites (TDEF; Oorani -OR and Puthupet - PP) over a 19-year interval (2001-2020). The total basal area in OR and PP increased respectively by 2.26 m2 ha-1 and 0.93 m2 ha-1. The total biomass and the carbon stock in OR and PP increased by 82% and 51% respectively. The dominant species Strychnos lenticellata showed an increase in its basal area by three-fold in OR, whereas, in PP, a marginal increase of 4% was observed. The lower diameter class (1-6 cm) showed an increase in basal area in OR and PP by 101% and 16% respectively. The mid-diameter class (6-11 cm) was the top contributor of the total biomass/carbon in both OR and PP in the latest re-inventory (2020). The present results show that lianas, although known to negatively affect the forest biomass/carbon stock, play an important role in carbon sequestration, thus providing insights into their ecological importance which will certainly be useful in proposing strategies for the conservation of this forest type dominated by lianas.

Diversity, Structural, and Regeneration Analysis of Woody Species in the Afromontane Dry Forest of Harego, Northeastern Ethiopia

The study was conducted in the Harego dry Afromontane forest, Northeastern Ethiopia, to analyze woody species composition, diversity, structure, and regeneration status. To collect the vegetation data, a total of 67 sample plots measuring 400 m 2 20 m × 20 m were laid systematically. Species identity, abundance, height, and diameter at breast height (DBH) were recorded for each sample plot. Diversity, structural, and regeneration status were analyzed for the forest. A total of 50 woody species representing 35 families and 44 genera were identified and recorded. According to the IUCN Red List Category, Rhus glutinosa A. Rich and Prunus africana (Hook.f.) Kalkm. are vulnerable species. Fabaceae was the dominant family, and of the total species, 27 were shrubs, 19 were trees, and 4 were climbers. The species accumulation curve indicates that the majority of plant species in the study area were captured by our sampling efforts. The values of true Shannon (N1 = 17) and true Simpson (N2 = 11) indicate that species in the Harego forest are more or less evenly distributed. The abundance-frequency ratio of all woody species (WI = &gt;0.05) indicates the heterogeneity of species composition. The total density and basal area were 4400 stems ha−1 and 9.66 m2 ha−1, respectively. The majority of the species fallen into the lower IVI classes. The diameter and height class distribution revealed an inverted J-shape. The increase in population demand and disturbance shows a high variation in stand structure and hampered natural regeneration, which needs immediate conservation actions.

Woody Plant Conservation Value of Three Contrasting Forest Management Regimes in Southwest Ethiopia

The future of the Afromontane forest of southwest Ethiopia is highly influenced by coffee management intensity. The study was conducted to investigate the woody species conservation value of a human-modified forest in southwest Ethiopia. We assessed woody species composition, regeneration and forest stand structure across three different management regimes (i.e., natural forest, coffee forest and coffee agroforest using 189 plots of 400 m2 (20 m × 20 m). A total of 64 species belonging to 33 families were identified and recorded across the three forest management regimes. About 83% of the recorded woody species were maintained in the coffee agroforest. The three forest types shared 61% of the recorded woody species. The coffee agroforest had maintained four strata or layers of stand structure. Nevertheless, the total abundance, density and basal area of woody species decreased from the natural forest to coffee forest and coffee agroforest. The Analysis of Similarity (ANOSIM) showed significant difference between the natural forest, coffee forest and coffee agroforest (Global RAnosim = 0.36, p &lt; 0.001). Similar regeneration patterns were recorded under the forest management regimes. Coffee agroforests simplify the woody plant composition and stand structure of the Afromontane forest in southwest Ethiopia.

Woody seedling community responses to deer herbivory, introduced shrubs, and ash mortality depend on canopy competition and site wetness

Emerald ash borer (EAB) (Agrilus planipennis), non-native shrubs, and white-tailed deer (Odocoileus virginianus) have been independently shown to affect woody seedling communities. Our objective was to determine the relative importance as well as additive and interactive-effects of these stressors in the context of two environmental factors, canopy tree competition and site wetness. We sampled 24 sites, representing three natural non-congruent gradients in ash mortality, deer browse, and introduced shrub invasion. We explored the responses of seedling species abundance, diversity and richness to an array of deer herbivory, ash mortality, and introduced shrubs and varying levels of canopy tree competition, site wetness. The effects of each stressor on the differences in the relative abundance of seedling species was also evaluated. Our results indicate a persistent negative effect of non-native shrubs in drier forest plots on native seedling abundance, richness, and diversity. In wetter forests, non-native shrubs had no effect on native seedling richness or abundance and were positively related to diversity. Deer browse had a negative effect on seedling diversity in wetter forests and no effect in drier forests. Canopy tree competition had a positive effect on seedling diversity in drier forest plots, but negatively affected diversity in wetter forest plots. Ordination analysis revealed that site wetness, non-native shrubs and the total basal area of trees in the stand had the largest impacts on the species composition of seedlings found at each site. Our results suggest that site wetness and chronic stressors like deer and introduced shrubs are interacting to shift seedling communities towards fewer native species as well as to reduce seedling species richness and diversity.

Comparison of Woody Species Diversity and Population Structure Along Disturbance Gradient in Babile Elephant Sanctuary, Ethiopia

Abstract The study was conducted at Babile Elephant Sanctuary (BES), to identify and document the list of woody species, and to analyze the diversity, richness, evenness, and population structural status of woody species. The diversity of plant species and population structure of woody species were analyzed from 60 quadrats, each with 20 m x 20 m for trees and 5 m x 5 m for shrubs and climbers, using systematic sampling methods with three levels of disturbances regime, namely, low disturbed (LD), moderately disturbed (MD) and heavily disturbed (HD) sites. Vegetation parameters such as diameter at breast height (DBH), richness, evenness, and density of woody species were recorded. Shannon Weiner Diversity Index was used to analysis vegetation diversity and evenness. A total of 61 woody species were identified in the study area that falls within 29 families and 38 genera of which 50.8 % were shrubs, 39.3 % were trees and the rest 9.83 % were climbers. Fabaceae was represented by the highest number of species (14 species = 22.90). The highest plant species richness was recorded from the low disturbed sites, followed by moderately disturbed and heavily disturbed sites respectively. The population density of vegetation was significantly higher in the MD site, followed by the LD site. The total basal area of LD, MD, and HD were 27.2, 19.8, and 11.2 m2/ha, respectively. LD site had significantly (P= 0.04) highest Shannon’s diversity index value (3.21) than the others two disturbance levels. This result suggests that the consequence of human-induced disturbance on woody species diversity and population structure appeared to be negative depending on the type and intensities of the disturbances.