Woody Plant Species Composition Research Articles

Quantifying the effects of landscape and habitat characteristics on structuring bird assemblages in urban habitat patches

Understanding the determinants of biodiversity in fragmented habitats is fundamental for informing sustainable landscape development, especially in urban landscapes that substantially fragment natural habitat. However, the relative roles of landscape and habitat characteristics, as emphasized by two competing frameworks (the island biogeography theory and the habitat diversity hypothesis), in structuring species assemblages in fragmented habitats have not been fully explored. This study investigated bird assemblages at 26 habitat patches (ranging in size from 0.3 to 290.4 ha) in an urban landscape, southwest China, among which habitat type composition and woody plant species composition varied significantly. Through 14 bird surveys conducted over six breeding seasons from 2017 to 2022, we recorded 70 breeding bird species (excluding birds recorded only once and fly-overs, such as raptors, swallows and swifts), with an average of 26 ± 10 (SD) species per patch. We found that patch area had significant direct and indirect effects on bird richness, with the indirect effects mediated by habitat richness (i.e., the number of habitat types). Isolation (measured as the distance to the nearest patch), perimeter to area ratio (PAR), and woody plant richness did not significantly predict variation in bird richness. Furthermore, none of these factors significantly sorted bird species based on their functional traits. However, the overall makeup of bird assemblages was significantly associated with the specific habitat types and woody plant species present in the patches. The results suggest that neither the island biogeography theory nor the habitat diversity hypothesis can fully explain the impacts of habitat fragmentation on bird richness in our study system, with their roles primarily being linked to patch area. The findings that habitat and plant compositions were the major drivers of variation in bird assemblage composition offer valuable insights into urban planning and green initiatives. Conservation efforts should focus not only on preserving large areas, but also on preventing urban monocultures by promoting diverse habitats within those areas, contributing to the persistence of meta-communities.

Woody Species Composition, Structure, and Status of Regeneration in Pugnido Forest, Gambella Region, Western Ethiopia.

Ethiopia is a biodiversity hotspot area with a high concentration of plant species that play countless roles in ecosystem resilience and mitigating the effects of climate change. However, forest resources are degrading at an alarming rate due to different anthropogenic factors. Pugnido Forest, which is among Ethiopia's greatest woodland sections, also faced a similar challenge. Thus, this study was intended to assess the composition, structure, and regeneration status of woody plant species in Pugnido Forest, West Ethiopia. Eighty main plots sized 20 × 20 m were sampled systematically on six east-west-oriented line transects, which are parallel to each other and 500 m apart. At the four corners and the center of the main plots, five subplots sized 2 m × 2 m were laid to collect seedling and sapling information. Individual woody species were identified and then recorded per plot. The forest structure and regeneration status data were recorded and analyzed using structural parameters. Communities were identified via cluster analysis. A comparison of diversity and composition among communities was made using the Shannon-Wiener diversity and Sorensen's similarity coefficients, respectively. A total of 106 woody species included in 40 families were documented. Fabaceae stands first in the species-rich family (23.6%), and Moraceae stands second (8.5%). Overall Shannon-Wiener diversity and evenness of species were 4.41 and 0.93, respectively. Four communities were generated from cluster analysis. Sorensen's similarity value among communities ranged from 42% to 59%. The forest's density and basal area were 5298.8 stems·ha-1 and 82.5 m2·ha-1, respectively. The trend in frequency and density classes showed a decreasing number of species towards higher classes. Diameter at breast height (DBH), height, and basal area analyses revealed a normal J-shaped pattern. Several species had a smaller importance value index (IVI) value. Density ratios of juveniles to adult plants indicated good regeneration status. Species with small IVI values and few or no seedlings require conservation priority. Top priority must be given to conserving species with low IVI values and few or no seedlings.

Farm management and landscape context shape plant diversity at wetland edges in the Prairie Pothole Region of Canada.

Evaluating the impacts of farming systems on biodiversity is increasingly important given the need to stem biodiversity loss, decrease fossil fuel dependency, and maintain ecosystem services benefiting farmers. We recorded woody and herbaceous plant species diversity, composition, and abundance in 43 wetland-adjacent prairie remnants beside crop fields managed using conventional, minimum tillage, organic, or perennial cover (wildlife-friendly) land management in the Prairie Pothole Region. We used a hierarchical framework to estimate diversity at regional and local scales (gamma, alpha), and how these are related through species turnover (beta diversity). We tested the expectation that gamma richness/evenness and beta diversity of all plants would be higher in remnants adjacent to perennial cover and organic fields than in conventional and minimum tillage fields. We expected the same findings for plants providing ecosystem services (bee-pollinated species) and disservices (introduced species). We predicted similar relative effects of land management on alpha diversity, but with the expectation that the benefits of organic farming would decrease with increasing grassland in surrounding landscapes. Gamma richness and evenness of all plants were highest for perennial cover, followed by minimum tillage, organic, and conventional sites. Bee-pollinated species followed a similar pattern for richness, but for evenness organic farming came second, after perennial cover sites, followed by minimum tillage and conventional. For introduced species, organic sites had the highest gamma richness and evenness. Grassland amount moderated the effect of land management type on all plants and bee-pollinated plant richness, but not as expected. The richness of organic sites increased with the amount of grassland in the surrounding landscape. Conversely, for conventional sites, richness increased as the amount of grassland in the landscape declined. Our results are consistent with the expectation that adopting wildlife-friendly land management practices can benefit biodiversity at regional and local scales, in particular the use of perennial cover to benefit plant diversity at regional scales. At more local extents, organic farming increased plant richness, but only when sufficient grassland was available in the surrounding landscape; organic farms also had the highest beta diversity for all plants and bee-pollinated plants. Maintaining native cover in agroecosystems, in addition to low-intensity farming practices, could sustain plant biodiversity and facilitate important ecosystem services.

Composition and diversity of woody plant species in agro-ecosystems of Uluguru Mountains, Tanzania

Woody plant species are important components of agro-ecosystems that determine their productivity and biodiversity conservation in tropical mountain landscapes. This study investigates woody plant species composition and diversity through simple random sampling of sixty (10 × 10 m) plots in crop fields, hedgerows, and homegardens at Uluguru Mountains, Morogoro, Tanzania. In total, 85 woody plant species, representing 82 genera and 40 families were recorded. The most species-rich families were Proteaceae (with 323 individuals), Lauraceae (205), and Meliaceae (185). Among the woody plant species, Grevillea robusta (Proteaceae) showed the highest importance value index of 41% across different agro-ecosystem types. Shannon (1.87), Simpson (0.82), and evenness (0.91) diversity indices were highest in hedgerows compared to other agro-ecosystems. Hedgerows recorded the maximum richness, followed by homegardens and lastly crop fields. Present agro-ecosystems should be promoted to enhance the restoration and conservation of agro-biodiversity in mountain landscapes.

Woody Plant Assemblages of Recently Declared Village Land Forest Reserve in The Eastern Afromontane Biodiversity Hotspot

Understanding of species composition of village land forest reserves and their driving factors informs adequate development of effective restoration strategies and sustainable forest management of miombo woodlands. This study assessed the effects of human disturbance as well as environmental variables on woody plant species composition using 24 square plots of 10 x 10 m in a recently declared village land forest reserve in the Eastern Afromontane biodiversity hotspot of Tanzania. Ordination analysis technique canonical correspondence analysis was used to identify important vegetation gradients and significant factors that explain the spatial variation in species composition of woody plants. Results showed that, 779 individual woody plants were recorded, of which 379 were seedlings (48.6%), 102 saplings (13.1%) and 298 adults (38.3%). The three most dominant plant species were Brachystegia spiciformis (42.2%), Diplorhynchus condylocarpon (9%) and B. boehmii (8.7%), while the least were Multidentia crassa and Diospyros squarrosa with each species having less than 1% overall abundance. Pterocarpus angolensis, a highly protected and near-threatened tree species, was also recorded but with only very few individuals. Canopy cover and soil pH were the two most important variables explaining the spatial variation in species composition of woody plants. These results emphasise that village forests are important for preserving native and threatened tree species, and improved management should discourage all practices that change natural conditions of canopy cover and soil pH to safeguard the remaining village forests, biodiversity and rural livelihoods.

Potential replacement understory woody plants for Robinia pseudoacacia plantations: species composition and vertical distribution pattern

Black locust ( Robinia pseudoacacia L.) plantations on the Loess Plateau have become multigenerational sprouting forests with an obvious trend toward degradation. The species composition and vertical distribution pattern of understory woody plants were investigated in mature stands located at the top (T_GS) and bottom (B_GS) of a slope in the gully region to explore whether there may be replacement species for black locust. The species composition of T_GS and B_GS clearly differed, and species diversity indices in B_GS were significantly greater than those in T_GS. These differences in species composition were mainly attributed to elevation, leaf area index, and basal area of total canopy trees. In T_GS, Rubus corchorifolius and Rosa xanthina had an absolute advantage in terms of the number of individuals in the vertical space of (0, 100] cm and (100, 300] cm, respectively. In B_GS, Acanthopanax senticosus was dominant at (0, 200] cm, and Broussonetia papyrifera and Celtis sinensis began to dominate at >200 cm. These results suggest that shrub species ( Rubus corchorifolius and Rosa xanthina) and tree species ( Broussonetia papyrifera and Celtis sinensis) should be prioritized when mixed with black locust in T_GS and B_GS, respectively, to gradually replace black locust on the Loess Plateau.

Variation in understorey floristic composition regeneration and fire hazard under Acacia invaded forest canopy in New Zealand

Acacia species are considered invasive exotic species in many regions globally, and influence the floristic composition and fire hazard of ecosystems they invade. Managing such species requires an understanding of their invasion capability, and persistence through succession in the community. New Zealand is one of the countries that have experienced Acacia invasion in the forest canopy, however, the potential long-term successional trajectories and future fire hazards of these communities have rarely been studied impeding management. We investigated the variation in woody plant species composition that was regenerating at different height tiers, and the comparative flammability of constituent species, under the canopy of Acacia-invaded forest sites in New Zealand, and evaluated the likely long-term changes in vegetation succession and fire hazards. From the floristic survey of 24 10 × 10 m plots in Acacia-invaded sites, we found a significantly higher number of native species (7.33 ± 0.67) than exotic species (4.83 ± 0.38) regenerating under Acacia-invaded canopies. While exotic stems dominated the lowest height tiers (<0.3 m), native stems outnumbered exotics at other understorey height tiers (0.3–2 m, 2–5 m and 5–12 m) and were recruiting successfully. We also found that invaded Acacia species and other exotic species at the sites were comparatively higher in flammability than most of the native species in the area, and can potentially increase the flammability of the invaded forest area if not managed appropriately. The successful regeneration and recruitment of natives in all height tiers under the Acacia canopy indicates a potential native succession in the longer term. Thus, the Acacia invasion can be managed through passive restoration where the dominant Acacia-invaded canopy in the forest area is replaced by native species, while also likely decreasing the fire hazard of the vegetation. This study provides evidence for the regeneration potential of native species in the understorey of Acacia-invaded forest sites and the knowledge helps forest managers make appropriate decisions to manage this woody exotic invasion and fire hazard of the invaded forest sites in New Zealand as well as other Acacia-invaded sites globally.

Woody species diversity and regeneration status of Sub-Alpine forest of Mount Adama exclosure site, Northwestern highlands of Ethiopia

Forests provide a wide range of ecosystem services. Despite these facts, the expansion of agriculture and settlement at the expense of forest resources has threatened the forest resources and results in biodiversity loss. To halt this problem, various conservation practices that believed to restore the degraded lands and biodiversity of the country have been implemented. Area exclosure is among the conservation strategies that have been used to restore the degraded lands in Mount Adama forest. However, its role in woody species regeneration in Mount Adama was not investigated. Thus, the objective of the study was to evaluate the impact of area exclosure on woody plant species composition, regeneration status, structure and diversity in Mount Adama. A systematic transect sampling method was used to collect vegetation data. Hence, 53 plots with 400 m2 area were laid along 11 transects. Then, within the main plots, five subplots with 1 m2 were laid to determine the abundance and frequency of seedlings. The results showed that about 31 woody species that belong to 30 genera and 19 families including four endemic species were identified. The majority (67.74%) of the species were categorized under shrub habitat, while the remaining 19.35% and 12.90% were trees and lianas or climbers, respectively. Asteraceae family was dominant by contributing 4 species followed by Rosaceae and Solanaceae each contributed 3 species. Hypericum revolutum was the dominant species with 53.38 important value index followed by Erica arborea and Hagenia abyssinica with 49.12 and 40.05, respectively. The overall Shannon- Wiener diversity index and Shannon evenness in the exclosure site were 2.6 and 0.73, respectively. Furthermore, the number of seedlings and saplings were higher in the exclosure than the untreated site. The results of the study evidently showed that area exclosure that implemented in Mount Adam successfully contributed to the biodiversity restoration. Therefore, further conservation efforts targeting species with low IVI values are needed for sustainable management and ecological recovery of the area.

Floristic Composition, Structure, and Regeneration Status of Woody Plant Species in Hurubu Natural Forest, North Shewa, Oromia Region, Ethiopia

Abstract Ethiopia harbour the Eastern afromontane and Horn of Africa hotspots of biodiversity. The general objective of this study was to investigate the floristic composition and diversity of species, the structure and the regeneration status of the Hurubu forest. Three parallel transects lines with 1 km length were systematically laid across the forest with an interval of 500 m in south to north direction. Thirty sample quadrants of 20 m × 20 m were placed along transects at an interval of 200 m for mature trees and shrubs, while for the purpose of seedling and sapling inventory, four sub-quadrants of 1 m × 1 m were laid at each corner of the main quadrant. A total of 32 woody species representing 25 families were recorded consisting of trees and shrubs. The lower storey consisted of all woody plant species, except Ekebergia capensis tree species. The middle storey consisted about 14.41 % of the tree species while the upper storey involved only 2.35 % of the total individual trees in the forest. The total basal area of woody plants in Hurubu forest was 90 m2 per ha. The three most important woody species with the highest IVI were Juniperus procera, Osyris quadripartite and Myrsine africana in decreasing order. The general regeneration status of the tree species of the study site was satisfactory at the community level showing a ‘fair’ regeneration status. Therefore, special conservation actions should be implemented for the poorly and not regenerating woody species of the forest.

Species Diversity, Structure, and Regeneration Status of Woody Plants in Saleda Yohans Church Forest, South Wollo, Ethiopia.

The study was conducted to determine woody plant species composition, structure, and regeneration status in Saleda Yohans Church forest, South Wollo Zone, Ethiopia. Five transect lines oriented to north-south directions at a distance of about 500 m were laid down along transects across the forest. Fifty main plots of 20 m × 20 m were laid for tree/shrub data collection. Within each main plot, 5 small quadrats of 5 m × 5 m were laid in the corners and centre for the collection of seedling and sapling data of woody species. All vegetation data within the plots were counted and recorded. Tree height and diameters at the breast height of plants were also measured and estimated. Moreover, frequency, basal area, diversity, evenness, and other vegetation data were analyzed. The result showed that this Church forest is composed of 50 woody plant species distributed in 31 families. The Shannon-Wiener diversity index and evenness values of the forest were found to be 3.82 and 0.84, respectively. Lamiaceae was the dominant family followed by Fabaceae in their species composition. The density of trees/shrubs, saplings, and seedlings was 625, 650, and 935 ha-1, respectively. Based on the result, the entire vegetation of Saleda Yohans Church forest is in good regeneration status. In conclusion, although this Church forest appears to be in a good regeneration status, its species richness is low compared to a similar study of some other vegetation. Therefore, attention should be given to the rehabilitation of this forest.

Floristic Composition and Structural Analysis of Woody Plant Species in Jib Godo Natural Forest, Farta District, South Gonder Zone, Amhara Region, Ethiopia

Afromontane forests are crucial for maintaining plant diversity and reducing climate change. Even though the Jib Godo Natural Forest is subject to anthropogenic impacts such as cutting and farming, it lacks long-term conservation practices. The researchers conducted fieldwork in Jib Godo Natural Forest to investigate the floristic composition and structural analyses of woody plant species in Ethiopia. The vegetation and environmental data were collected from 50 (20 m × 20 m) sample plots established for woody species at every 100 m along seven transect lines and 5 m × 5 m in five subplots for saplings and seedlings using a systematic sampling procedure. In each sample plot, soil samples were obtained from 0–20 cm and mixed to generate a composite sample. A vegetative structural analysis of DBH, height, and stem IVI was computed. There were 65 species of woody plant identified, belonging to 58 genera and 41 families, with 34 species (52.30 percent) being trees, 23 species (35.38 percent) being shrubs, and 8 species (12.30 percent) being lianas. Outside of the sample plot, four other species were identified. Only eleven environmental characteristics were significant at p &lt; 0.05, according to the results of canonical correspondence analysis (CCA). In conclusion, the distribution of plant communities and the composition of the species depend on altitude and topographic aspects. The forest’s population structure and regeneration condition suggested that the area had experienced forest degradation and severe anthropogenic disturbances; therefore, the conservation of species and sustainable use of forest genetic resources are advocated as a result of this study’s findings.

Floristic composition and community analysis of woody species in Hereje Natural Forest, southwest Ethiopia

The floristic composition, diversity, and conservation status of woody plant species in Ethiopia are determined in this study. Data on vegetation are collected using a systematic random sampling method from 45 20 m × 20 m (400m2) plots laid every 100 m along four parallel transect lines running from south to north. The Flora of Ethiopia and Eritrea identification key (Volume I–VIII) is used to identify the scientific names of all woody plant species. The Shannon–Wiener diversity index is used to calculate species diversity, whereas Sorensen's similarity coefficient is used to assess similarities and differences among plant communities. The studied forest contains 44 plant species from 29 families and 40 genera. The Fabaceae is the most dominant family, followed by the Rubiaceae and Combretaceae. In terms of habit, the collected woody species consisted of 30 (68.2%) trees and 14 (31.8%) shrubs. The two most frequent species are Syzygium guineense (51.11%) and Maytenus gracilipes (46.66%). Three plant community types are identified using Agglomerative Hierarchical Cluster Analysis. Most species (Calpurnia aurea-Combretum molle) are observed in community type two. The study is generally limited to the floristic and diversity of woody plant species. Therefore, a thorough investigation of all species' floristic composition, population structure, regeneration status, and ecological aspects is recommended.

Dendroflora in spatial planning compositions of children’s squares in Vyshhorod town

Various groups of urban residents, including children, need to ensure a high-quality environment. One of the important features of urban plantings is their biodiversity, which is often low in the territories of children’s facilities. The purpose of the study is to identify spatial planning solutions and assess the species composition of tree plantations on the territory of six newly created children’s parks of the small historical city of Vyshhorod, Kyiv Oblast, which is located near the capital and is marked by positive demographic dynamics. The initial data were obtained as a result of the authors’ inventory survey of vegetation in these parks. The spatial planning composition of the dendroflora of these parks is also analysed using a visual method. Based on the obtained data, the level of biodiversity of tree stands in parks under study was estimated: the available number of taxa, Menhinick’s richness and diversity index, and the Berger-Parker abundance index were compared. On the territory of these parks, a total of 70 taxa of woody and shrubby plants were identified, among which introduced species predominate. More than half of the identified taxa are found only in one of the parks. The most common types represented on the territory of most children’s parks are the following: Spiraea vanhouttei, Juglans regia, Physocarpus opulifolius. Cluster analysis revealed groups of parks with a similar assortment of woody plants, and, accordingly, similar biodiversity indicators. The relationship between the assortment of plants and the general spatial solution of parks is traced. It was concluded that the selection of the species composition of woody plants for children’s parks should be more thorough, and it is also advisable not to exceed the recommended 10% share of one species in the composition of plantings. The use of “thorny” species that are not recommended for children’s territories is quite balanced and rational. The use of the findings in urban planning would help create a multifunctional eco-balanced children’s space and increase the sustainability of urban ecosystems

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.

Beaver foraging patterns in a human-dominated landscape: Effects on woody vegetation and mammals

Beavers can change habitat composition by cutting down trees, digging, and damming activities, thereby affecting species richness and abundance. Although there is large body of literature regarding the effects of beaver activity on a wide range of taxonomic groups, relatively little is known about how space use by ungulates is affected by beavers in the human-dominated landscapes of Europe. Here, we present a case study from Denmark that investigated potential effects of beaver activity on mammals, with a special focus on roe deer and red deer. Beavers could either facilitate the presence of deer by providing food resources (increased abundance of deciduous trees and shrubs) or compete with them for resources. Using transect counts recording both cut and uncut stems of woody plants, we describe beaver browsing patterns, providing evidence that they either select for areas with higher woody vegetation richness and diversity, or alter woody plant species composition. We then assessed deer presence and relative abundance in relation to the distance from water and in areas with varying beaver activity. Our findings provide limited evidence for exploitative competition between beavers and roe and red deer, as roe and red deer avoided proximity to water in areas with high beaver activity, and deer numbers were higher in areas with low beaver activity. We speculate that the weak effect of beaver activity on deer (and/or vice versa) might be related to the large human impacts in the area, e.g., forest management, potentially superseding effects of interspecific competition. An improved understanding of the complex effects beavers can have on ungulates in human-dominated landscapes will be relevant for wildlife and forestry management, potentially being an important tool to reduce human-wildlife conflicts.

Associations between Epiphytic Bryophyte and Woody Plant Species in a Temperate Deciduous Broad-Leaved Forest

Determining whether epiphytic bryophytes have ecological preferences for woody plants remains difficult. Here, our primary aim in developing the torus-translation test is to evaluate the associations between epiphytic bryophytes and woody plants at the species, genus, or family levels in a 100 m × 100 m forest dynamics plot in a temperate, deciduous broad-leaved forest (China). We collected all the epiphytic bryophyte species on woody plants and recorded the woody plant species in the 1-ha plot in 2020. All the epiphytic bryophytes on the trees from the ground level up to 2 m were collected. We recorded 988 epiphytic bryophyte specimens belonging to 61 species in 254 woody plants. The Torus-translation test showed that 93.44% (57/61), 93.44% (57/61), and 98.36% (60/61) of the bryophyte species were significantly positively associated with the family, genus, and species of woody plants, respectively. A total of 317, 563, and 857 significant positive associations concerning the family, genus, and species of the woody plants were observed among the 61 examined bryophyte species. In addition, few significant negative associations were identified regarding the family, genus, and species of woody plants. More rare bryophyte species were positively correlated with woody plants than dominant bryophyte species. Our study demonstrates that most epiphytic bryophytes exhibit ecological habitat preferences for woody plants. These observations highlight the importance of the species composition of woody plants with respect to the maintenance of epiphytic bryophytes’ diversity. Epiphytic bryophytes’ growth preference for woody plants, especially rare bryophyte species, should be considered in the process of bryophyte diversity conservation in temperate, deciduous broad-leaved forests.

Determination of the species structure of phytocenoses of the natural age oak forest of the Dendrological Park "Olexandria" of the National Academy of Sciences of Ukraine

The modern species composition of woody plants of the centuries-old oak grove of the State Dendrological Park "Olexandria" of the National Academy of Sciences of Ukraine was studied.&#x0D; The work was carried out as part of the study of the dynamics of stands of oak phytocenoses under conditions of anthropogenic load, technogenic pollution and weather fluctuations.&#x0D; It has been established that the oak grove of the arboretum with an area of 446 hectares out of 2000 oaks is a complex multi-species planting. The floristic core of the oak forest consists of the main forest-forming species characteristic of the Right-Bank Forest-Steppe of Ukraine: Quercus robur, Acer platanoides L. and Acer campestre L., Fraxinus excelsior L., Tilia cordata Mill., Carpinus betulus L., Ulmus scabra Mill. The role of the dominant species and edificator was retained by Quercus robur. In the worst growing conditions, monodominant stands are formed. In more favorable ecotopes in the upper tree layer, the participation of Quercus robur is 70–100 %, and its codominant satellites (Acer platanoides, Tilia cordata, Fraxinus excelsior) are 10 % each. All oak forest phytocenoses have a well-developed multi-species second tree layer: Acer platanoides (15–80 % in various phytocenoses), Acer campestre (10–30 %), Tilia cordata (10–60 %), in some phytocenoses Fraxinus excelsior (10–20 %), Ulmus scabra (10–20 %), Carpinus betulus (30 %).&#x0D; The group of asectators is diverse and is represented by small species, local and adventive species, introducers, including invasive species.&#x0D; A characteristic feature of the oak forest is its exorbitant crushing, which, along with the massive introduction of introduced species, caused a powerful ecotonization of the oak forest and formed the cells of the greatest mortality of Quercus robur.&#x0D; The conducted studies establish the modern species composition of the oak forest and are the basis for the study of succession processes in oak forest phytocenoses.

Floristic composition, growth temperament and conservation status of woody plant species in the Cameroonian tropical rainforests

IntroductionCameroon’s tropical rainforests are nowadays strewn with rural forests maintained by local populations; however, these forests are not officially recognized in the non-permanent forest domain. Rural forests are non-delimited riparian areas within the dense moist forest, reserved for rural housing, agricultural activities and agroforestry practices, freely exploited by the local communities for their livelihood without them having any rights to artisanal and commercial logging. This study aimed at contributing to the flora knowledge and the conservation state of woody plant species in rainforests. The study was carried out in two rural forests located in the Eastern and Southern agroforestry zones of Cameroon.MethodsThe method adopted for floristic inventories combined a fixed area sampling unit and a variable area sampling unit. Woody individuals with diameter at breast height (dbh) < 3.2 cm were counted and shrubs of 3.2 ≤ dbh < 10 cm were measured to analyse the understorey, while trees with dbh ≥ 10 cm were measured and identified to characterize the canopy.ResultsIn the Essiengbot-Mbankoho rural forest in Eastern Cameroon, 468 species belonging to 61 families were recorded in the understory while 227 species belonging to 53 families were identified at the canopy level. A total of 40 (7.68%) threatened species, 18 (3.45%) Near Threatened species and 408 (78.31%) Least Concern species were recorded. In the Nbgwassa-Opkweng rural forest in Southern Cameroon, 534 species belonging to 64 families were identified in the understory while 225 species belonging to 43 families were recorded in the canopy. A total of 54 (9.69%) threatened species, 25 (4.49%) Near Threatened species and 421 (75.58%) Least Concern species were identified in this forest. Shannon’s diversity indices were above five in the understories and canopies of both forests. Shade-bearer species were the most represented in the understories while the non-pioneer light-demanding and shade-bearer species were the most abundant in the canopies.ConclusionsDespite the influence of slash-and-burn agriculture and subsistence farming practices, rural forests managed by local populations provide opportunities for preserving plant biodiversity. However, the presence of threatened species, pioneer species and non-pioneer light-demanding species in these forests is an indicator of moderate and man-induced disturbances that, in the absence of a forest management plan or sustainable management, may threaten this biodiversity. Legal management of rural forests could help in limiting the anthropogenic activities and pressures on community forests.

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.

Invasive alien species of woody and shrubby plants and assessment of their phytocenotic aggressiveness in the State Regional Nature Park “Medeu”

The aim of the work was to determine the species composition of woody and shrubby plants of the State Natural Park “Medeu” and to identify invasive species. For the first time, an assessment of the aggressiveness of invasive species and their impact on the ecosystem was carried out. The article provides an analysis of the dendroflora of the GRPP “Medeu”. The species composition of native and invasive species was revealed, the degree of aggressiveness of the latter and the peculiarities of their distribution were analyzed using the species abundance assessment scale. It is shown that the uncontrolled spread by self-seeding and overgrowth of particularly aggressive plant species such as Acer campestre, Acer negundo, Fraxinus excelsior has a depressing effect on the local natural flora, leads to the homogenization of ecosystems and a decrease in the biodiversity of cenoses, by reducing the number of individual species and reducing their ranges. This may further lead to the complete destruction of wild fruit forests growing in this region, and disruption of the ecosystem of plant communities in which red Book plants grow. During the survey conducted on the territory of the Medeu State Regional Natural Park were identified 35 naturally growing species of trees and shrubs 5 of which are red-listed, 27 alien species, three of which are classified as aggressive, and 13 invasive species that may eventually become aggressive.