Species Importance Values Research Articles

Eco-systematic assessment of the spring herbaceous vegetation under edaphic and topographic effects

The distribution and composition of the vegetation are greatly affected by the edaphology and topography of an area. The current study explores the vegetation structure of the herbaceous layer at various habitats of district Kohat for the first time. A survey was conducted during the spring seasons of 2021, 2022 and 2023 selecting 40 sites on the basis of edaphology, topography, altitude, aspect and status. Data was collected via quadrat approach to establish plant communities by species Importance Value (IV), point out dominant species by Total IV (TIV) and dominant families via Total Family IV (TFIV). The quantitative biological spectrum was also calculated. Communities’ phytosociological characteristics were analyzed via various diversity indices (Shannon’s Index (H), Simpson’s Index (D), Species Richness (SR), Evenness (E) and Maturity index (Mi)) while similarity between the communities was calculated by using Sorensen’s Index. The findings revealed a total of 253 species belonging to 57 families having the dominant species Cynodon dactylon (L.) Pers. (TIV, 484.3) followed by Saussuria heteromalla (D. Don) Hand. (TIV, 360.4), Anagallis arvensis L. (TIV, 353.2) and Aristida adscensionis L. (TIV, 349.65). Among 40 plant communities, Poaceae (TFIV, 2706.6), Asteraceae (TFIV, 2018.8), Fabaceae (TFIV, 1071.5) and Brassicaceae (TFIV, 825.9) were the dominant families. Therophytes (TIV, 7882) class was the dominant life form class followed by hemicryptophytes (TIV, 2517) while microphylls (TIV, 4669) class was the dominant leaf size class followed by nanophylls (TIV, 5469). Environmental factors i.e. topography and edaphic characteristics, showed significant effects on the diversity of the communities. The study concludes in a diverse pattern of distribution with a rich flora in the area warranting its documentation which will preserve the valuable species opening vistas for future research.

DIVERSITY OF MANGROVES AND ASSOCIATED PLANTS IN MANDANGISIAO ESTUARY, MISAMIS ORIENTAL, PHILIPPINES

The study aimed to assess the diversity status of mangroves and associates. Four transect lines were established perpendicular to the shoreline, ranging from 20 to 100 meters based on mangrove stand size. Along these transects, three 10 m × 10 m quadrat plots were set up to evaluate mangrove trees, and within each quadrat, a 2 m × 2 m regeneration plot was established. The study calculated the di-versity indices, such as relative frequency, relative density, and relative dominance to determine the species im-portance value. A total of four mangrove species and two associated plants were identified, representing three mangrove families and three genera, as well as three plant families and three genera for associated plants. The record-ed species included Avicennia marina, Nypa fruticans, Rhizophora mucronata, Sonneratia caseolaris, Acanthus ebrac-teatus, and Acrostichum speciosum. The overall diversity value of the mangroves and associated plants was 0.87, indi-cating relatively low species richness. The true mangroves, Rhizophora mucronata exhibited the highest values for relative density (68.07%), while Nypa fruticans is the highest in terms of relative dominance (42.20%). Both have the same highest value in relative frequency (32.43%). All in all, the highest species importance value for true mangroves is Rhizophora mucronata with 126.23%. In associated plants, highest value of relative density and relative frequency belongs to Acanthus ebracteatus with 58% and 60%, respectively. Subsequently, the highest species importance value for associated plants is 118% for Acanthus ebracteatus. The study concluded that the Mandangisiao Estuary in Jasaan, Misamis Oriental has a limited species diversity, contrary to the initial hypothesis. Furthermore, the mangrove forest in the estuary faces potential threats from garbage dumping, tree cutting, boat mooring, and human encroachment, despite all the recorded species having a Least Concern conservation status.

Potential distribution and ecological impacts of Acmella radicans (Jacquin) R.K. Jansen (a new Yunnan invasive species record) in China

Background Acmella radicans(Jacquin) R.K. Jansen is a new invasive species record for Yunnan Province, China. Native to Central America, it has also been recently recorded invading other parts of Asia. To prevent this weed from becoming a serious issue, an assessment of its ecological impacts and potential distribution is needed. We predicted the potential distribution of A. radicans in China using the MaxEnt model and its ecological impacts on local plant communities and soil nutrients were explored.ResultsSimulated training using model parameters produced an area under curve value of 0.974, providing a high degree of confidence in model predictions. Environmental variables with the greatest predictive power were precipitation of wettest month, isothermality, topsoil TEB (total exchangeable bases), and precipitation seasonality, with a cumulative contribution of more than 72.70% and a cumulative permutation importance of more than 69.20%. The predicted potential suitable area of A. radicans in China is concentrated in the southern region. Projected areas of A. radicans ranked as high and moderately suitable comprised 5425 and 26,338 km2, accounting for 0.06 and 0.27% of the Chinese mainland area, respectively. Over the 5 years of monitoring, the population density of A. radicans increased while at the same time the population density and importance values of most other plant species declined markedly. Community species richness, diversity, and evenness values significantly declined. Soil organic matter, total N, total P, available N, and available P concentrations decreased significantly with increasing plant cover of A. radicans, whereas pH, total K and available K increased.ConclusionOur study was the first to show that A. radicans is predicted to expand its range in China and may profoundly affect plant communities, species diversity, and the soil environment. Early warning and monitoring of A. radicans must be pursued with greater vigilance in southern China to prevent its further spread.

Impacts of Soil Properties on Species Diversity and Structure in Alternanthera philoxeroides-Invaded and Native Plant Communities.

Soil properties can affect plant population dynamics and the coexistence of native and invasive plants, thus potentially affecting community structure and invasion trends. However, the different impacts of soil physicochemical properties on species diversity and structure in native and invaded plant communities remain unclear. In this study, we established a total of 30 Alternanthera philoxeroides-invaded plots and 30 control plots in an area at the geographical boundary between North and South China. We compared the differences in species composition between the invaded and native plant communities, and we then used the methods of regression analysis, redundancy analysis (RDA), and canonical correspondence analysis (CCA) to examine the impacts of soil physicochemical properties on four α-diversity indices and the species distribution of these two types of communities. We found that A. philoxeroides invasion increased the difference between the importance values of dominant plant species, and the invasion coverage had a negative relationship with the soil-available potassium (R2 = 0.135; p = 0.046) and Patrick richness index (R2 = 0.322; p < 0.001). In the native communities, the species diversity was determined with soil chemical properties, the Patrick richness index, the Simpson dominance index, and the Shannon-Wiener diversity index, which all decreased with the increase in soil pH value, available potassium, organic matter, and ammonium nitrogen. However, in the invaded communities, the species diversity was determined by soil physical properties; the Pielou evenness index increased with increasing non-capillary porosity but decreased with increasing capillary porosity. The determinants of species distribution in the native communities were soil porosity and nitrate nitrogen, while the determinants in the invaded communities were soil bulk density and available potassium. In addition, compared with the native communities, the clustering degree of species distribution in the invaded communities intensified. Our study indicates that species diversity and distribution have significant heterogeneous responses to soil physicochemical properties between A. philoxeroides-invaded and native plant communities. Thus, we need to intensify the monitoring of soil properties in invaded habitats and conduct biotic replacement strategies based on the heterogeneous responses of native and invaded communities to effectively prevent the biotic homogenization that is caused by plant invasions under environmental changes.

Changing Dynamic of Tree Species Composition and Diversity: A Case Study of Secondary Forests in Northern China in Response to Climate Change

Climate warming is believed to have irreversible effects on biodiversity and ecosystem functions. Secondary forests are non-negligible ecosystems in northern China that have attracted much attention because of their instability and sensitivity to global change. However, there is no consensus on the impact of warming on secondary forest succession. In this study, we explored the response of tree species diversity to climate warming in northern secondary forests in China using a series of field surveys combined with annual meteorological data from 2015 to 2021. Our results indicate that the temperature in the study area increased in spring and autumn, while the precipitation increased in spring, summer, and autumn from 2015 to 2021. Changes in species composition in the study area and climate warming were significant in the northern region of China. The importance values of many broadleaf tree species increased, whereas those of local coniferous and broadleaf tree species decreased. The Shannon–Wiener, Simpson, and Margalef indices for the pure forest were significantly lower than those for the broadleaf mixed forest and the conifer–broadleaf mixed forest (p &lt; 0.05) in 2015 and 2021. The highest value for the Pielou index was in the conifer–broadleaf mixed forest (p &lt; 0.05), whereas it was not significantly different between the pure forest and broadleaf mixed forest in 2021. Surprisingly, the secondary broadleaf mixed forest in northern China showed an unfavorable degradation trend under the influence of climate change, just the same as the secondary pure forest. Our work provides an experimental data source for research on secondary forests under various climate change scenarios and is an important reference for predicting and dealing with the impact of global climate change on the adaptive management and protection of secondary ecosystems.

Leaf traits are good predictors of woody species distribution after bamboo expansion in a mountain forest

The expansion of bamboo into neighboring plant communities is a common phenomenon in nature reserves. However, the role of climate factors and plant functional traits in the distribution of woody species after bamboo expansion remains unclear. Six functional traits of leaves of 180 individuals of 52 species, soil properties and air temperature were measured along an elevational gradient with different bamboo densities on Mt. Fanjingshan, Tongren City, Guizhou. Then, the direct and indirect effects of climate, soil properties, leaf traits and bamboo density on woody species distribution were detected. Our results showed that leaf traits were represented by two independent dimensions. The first dimension (PC1) is represented by the trade-off between the pairs leaf P, leaf N and leaf dry matter content, leaf C, representing nutrient use efficiency (NUE). The second dimension (PC2) was positively associated with leaf area, specific leaf area and leaf N, representing the leaf economics spectrum (LES). Climate, soil, leaf traits and bamboo density significantly explained 18% and 21% of the variance in species importance values for all species and evergreen species, respectively, but not for deciduous species. Air temperature had a positive indirect impact on the species importance value of all species via a negative direct impact on PC2, and air temperature affected the evergreen species importance value in two indirect ways: the first was to affect the species importance value positively and indirectly via PC2; the second was to affect the species importance value positively and indirectly through PC2 and PC1. However, bamboo expansion alone had no significant direct or indirect effects on species distribution. These results suggest that leaf traits are good predictors of woody species distribution after bamboo expansion in a mountain forest, and the effects of bamboo expansion are dependent on tree growth type, air temperature and leaf traits.

Spatial and temporal regeneration patterns within gaps in the primary forests vs. secondary forests of Northeast China

Forest gaps play an important role during forest succession in temperate forest ecosystems. However, the differences in spatial distribution and replacement patterns of woody plants (trees and shrubs) between primary and secondary forests remain unclear during the gap-filling processes, especially for temperate forests in Northeast China. We recorded 45,619 regenerated trees and shrubs in young gaps (&amp;lt;10 years), old gaps (10~20 years), and closed forest stands (i.e., filled gaps) in the primary broadleaved Korean pine (Pinus koraiensis Sieb. Rt Zucc.) forests vs. secondary forests (degraded from primary forests). The gap-filling processes along horizontal (Cartesian coordinate system) and vertical (lower layer: 0~5 m, medium layer: 5~10 m, and upper layer: &amp;gt;10 m) dimensions were quantified by shade tolerance groups of trees and shrubs. We found that gap age, competition between species, and pre-existing regeneration status resulted in different species replacement patterns within gaps in primary vs. secondary forests. Gap formation in both primary and secondary forests increased species richness, with 33, 38, 39, and 41 in the primary closed stands, primary forest gaps, secondary closed stands, and secondary forest gaps, respectively. However, only 35.9% of species in primary forest gaps and 34.1% in secondary forest gaps successfully reached the upper layer. Based on the importance values (IVs) of tree species across different canopy heights, light-demanding trees in the upper layer of the secondary forests were gradually replaced by intermediate and shade-tolerant trees. In the primary forests, Korean pine exhibited intermittent growth patterns at different canopy heights, while it had continuous regeneration along vertical height gradients in the secondary forests. The differences in Korean pine regeneration between the primary and secondary forests existed before gap formation and continued during the gap-filling processes. The interspecific competition among different tree species gradually decreased with increasing vertical height, and compared to the primary forests, the secondary forests showed an earlier occurrence of competition exclusion within gaps. Our findings revealed the species replacement patterns within gaps and provided a further understanding of the competition dynamics among tree species during the gap-filling processes.

Impacts of Grazing on Vegetation and Soil Physicochemical Properties in Northern Yinshan Mountain Grasslands

The grasslands at the northern foot of the Yinshan Mountains are an integral component of the northern grassland ecosystem in China. The ecosystem in this region has low stability and poor resistance to disturbance. In this study, experiments were conducted to evaluate the possible changes in vegetation community structure and soil physicochemical properties due to overgrazing in the grasslands. Completely randomized group experiments were designed with grazing intensity as the single-factor study was conducted using natural grassland located in Xilamuren (in Inner Mongolia, northern China) as the study area. Three blocks were created, each having four plots of different grazing intensities and each block having an area of 100 m × 100 m. The experiments were conducted to evaluate the possible variances both in the structure of the vegetation community and the soil physicochemical properties resulting from overgrazing in the grasslands at the northern foot of Yinshan Mountain. The results were as follows: The importance values of dominant species, such as Heteropappus altaicus and Artimisia gmelinii, exhibited varying degrees of change with an increase in the grazing intensity. The surface vegetation cover decreased significantly with an increase in the grazing intensity. The increasing grazing intensity led to a significant increase in the content of very coarse sand grains in the soil. Severe grazing increased the exposed surface area, intensified the effects of blowing wind and scouring action of water, and led to the coarsening of topsoil particles. At 0–5 cm depth, the bulk density of soil exhibited an increasing tendency with an increase in the grazing intensity. The organic matter content of the soil in the heavily grazed plots decreased by 11.74%, 11.00%, and 14.08%, respectively, when compared to that in the 0–40 cm soil layer with no grazing, light grazing, and moderate grazing. The results emphasized the importance of managing grazing intensity for soil and vegetation restoration. Thus, the effects of short-term grazing (for example, 5 years) on vegetation community composition and species diversity may be less pronounced. This study contributes to our understanding of pasture management and the restoration of grassland species diversity.

Assessment on Endangered Plant Biodiversity of Shirui National Park, Ukhrul, Manipur, India

Five different random sites were analyzed for the study of the plant species using quadrat methods from Shirui National Park. The plants were measured and recorded by random sampling with 20 quadrats of 10m ×10m in each study site during the period between January 2023 and April 2023.Site 4 Showed the maximum parameter for IVI value of Plant Species which was represent by Bidens Pilosa with the value of 130.7 Site 5 Showed the minimum parameter for IVI value of Plant Species which was represent by Lliliummackliniae with the value of 24. The IVI results show that the plant species importance values differs from site to site. From the study Llilium Mackliniae (Shirui Lily) is found decreasing in population, a species which is only endemic to Shirui National Park, Manipur.

The plant community of a stretch of riparian vegetation in the upper Paraná River after 20 years of secondary succession (Batayporã, Mato Grosso do Sul, Brazil)

The study of temporal changes in riparian vegetation is essential for understanding the paths taken by the ecosystem during ecological succession. In order to evaluate the changes in floristic composition, structure, and dynamics of the arboreal vegetation in an area of Semideciduous Seasonal Alluvial Forest, we aim to understand the secondary succession that occurs in the Paraná River floodplain. Based on a study conducted 20 years ago, in the municipality of Batayporã, Mato Grosso do Sul, a re-sampling was carried out in the same area, using the same methodology. Phytosociological and ecological parameters between the two temporal samplings were collected and compared using Student's ‘t’ test, where it was possible to find statistically significant variations (p&lt;0.05) in the vegetation structure. A total of 603 individuals were sampled, distributed among 51 species and grouped in 46 genera and 31 families. The analysis of the distribution of abundance and importance values (IV) of species visualized in the histogram indicated an expected pattern in forest communities, which is the substitution of early successional species for late successional species. For the successional categories, the comparison of IVs revealed higher values for secondary species in both surveys and changes in the positions of climax and pioneer species, directly influencing the IVs values of these categories for the zones. When compared to the result obtained in the previous study, a replacement of the IV values of pioneer species with climax and dead species is noted. The comparisons showed that this phytocoenosis is evolving to a mature successional stage, a result of the decrease in the main anthropic impacts in the area. The results obtained highlight the importance of temporal monitoring of forest areas to expand the understanding of the pathways of ecological succession in this type of environment and provide information to assist in biodiversity conservation.

Fine Root Production and Its Benefaction to carbon storage of the Sundarbans Mangrove Forest

The quantification of fine root production (FRP) and biomass (FRB) is of utmost importance in gaining insights into ecosystem dynamics. However, these aspects have received limited attention in mangrove forests, primarily due to the considerable time and labor required for accurate assessment. Therefore, our study aims to estimate FRP and FRB stocks in the Sundarbans mangrove forest in Bangladesh, specifically focusing on two distinct saline zones: oligohaline and mesohaline. To accomplish our objectives, we employed soil coring and long-term ingrowth core methods to collect soil samples from 20 study plots, each covering an area of 200 square meters. Additionally, we assessed the forest structure by measuring the tree height and diameter at breast height. Our findings revealed that the mean FRB and FRP across the study area were 12.65±1.12 Mgha-1 and 2.25±0.13 Mgha-1 y-1, respectively. Notably, the oligohaline zone, characterized by lower salinity levels, exhibited higher FRB stocks and FRP compared to the mesohaline zone. Furthermore, our analysis showed that FRP in the diameter class of 1-2 mm surpassed that of the 0.5-1 mm and ≤0.5 mm classes. In terms of biomass, the mean above-ground, below-ground, and total biomass carbon were determined to be 87.18 ± 18.3, 48.38 ± 8.0, and 135.57 ± 26.3 Mgha-1, respectively. Through species importance value (Iv) analysis, we identified Excoecaria agallocha as the dominant species in the oligohaline zone, while Sonneratia apetala exhibited the highest Iv value in the mesohaline area. Heritiera fomes emerged as the primary contributor to total biomass carbon, particularly in the oligohaline zone, whereas S. apetala contributed the most biomass carbon in the mesohaline zone. These findings emphasize the importance of protecting and conserving mangrove ecosystems as valuable contributors to global carbon dynamics due to its higher fine root production and its contribution to carbon stocks.

Importance Values of Mycorrhizal Fungal Types and Species Diversity Driving Variations in Fungi- and Bacteria-Derived Residues in Planted Forests in Northeast China

Aims: Microbial residue deposition is considered an important part of soil carbon sequestration. However, there is still a lack of understanding of the link between tree species composition and diversity and microbial carbon deposition, which hampers the rational selection and allocation of tree species for artificial carbon sequestration afforestation in northern China. Methods: In this study, plots from temperate planting forests (&gt;60 years) were examined for the importance values of tree species, mycorrhizal types, tree diversity, and soil properties. Soil amino sugar was used as the biomarker to indicate the accumulation of fungi- and bacteria-derived carbon. Results: We found that tree species diversity and the importance values of tree species and mycorrhizal types were significantly positively correlated with soil microbial residual carbon. Hierarchical partitioning modeling showed that three groups of variables significantly affected soil microbial residual carbon, accounting for a total of 26.75% of the variation. Among them, tree species diversity accounted for the largest proportion (11.5%), and tree species diversity and importance values had a high joint impact (9.74%). The importance values of all AM-associated species constituted one of the most significant individual factors and could independently account for 10.9% of the variation in microbial residues. The findings of piecewise structural equation modeling showed that the importance of tree species had a large direct impact on GluN, GalN, and the GluN/MurN ratio. By influencing soil properties, the importance values of tree species also had indirect effects on soil microbial residual carbon. Conclusions: We suggest that an increase in the importance values of AM-associated tree species, such as Acer negundo L., will be accompanied by an increase in the total importance value of AM-associated tree species, which can significantly increase soil microbial residual carbon.

Tree diversity, vegetation structure and management of mangrove systems on Viti Levu, Fiji Islands

Mangrove forest ecosystems are critical natural resources, particularly in the South Pacific region. Mangrove forests in Viti Levu, Fiji’s main island, are threatened by infrastructure development activities and population growth. Consequently, the protection and restoration of mangrove forest are of utmost importance. This study investigated the diversity and structure of mangrove forest on Viti Levu to determine the most appropriate species for use in restoration projects. These species could enhance the management of mangroves in Fiji. Five sites were selected: Ellington Wharf (EW), Naboutini Village (NV), Nasese (NA), Suva City Council Park (SCCP) and the University of the South Pacific Upper Campus (UUC). The variations in the number of tree stumps from site-tosite highlighted differences in the degree of anthropogenic disturbances, EW was classified as an undisturbed site while NA was highly disturbed. The sites were examined using systematic line transects with random starting points. Continuous belt transects were established, along which 10 m × 10 m segments were selected as the primary plots (n = 100 primary plots). Tree species, stand structure, tree diameter and height, stem abundance, stand volume, basal area and natural regeneration were recorded at all sites. Five mangrove species (Rhizophora stylosa Griff., Bruguiera gymnorhiza (L.) Lam., Excoecaria agallocha (L.), Rhizophora samoensis (Hochr.) Salvoza, and Rhizophora × selala (Salvoza) Toml.) were identified. The species importance value indices were highest for R. stylosa at EW (264.0) and for B. gymnorhiza) at NV (175.2). All sites had at least some level of human disturbance but R. stylosa and B. gymnorhiza thrived regardless of the extent of anthropogenic impacts. Subsequently, R. stylosa and B. gymnorhiza are recommended for mangrove forest ecosystem restoration programmes in Fiji.

Niche and Interspecific Association of Dominant Tree Species in Spruce–Fir Mixed Forests in Northeast China

This study focuses on the natural coniferous and broad-leaved mixed forest dominated by Picea asperata and Abies fabri in the Jingouling Forest Farm of Northeast China. Specifically, we place emphasis on examining the effects of different thinning intensities. By comparing the niche characteristics and interspecific associations of dominant tree species under various thinning intensity conditions, our aim is to gain deeper insights into the patterns of resource utilization by species and the interplay of tree species in the forest canopy. Based on plot survey data, analysis methods such as niche breadth, niche overlap index, Pearson correlation coefficient, and Spearman’s rank correlation coefficient were used to analyze the niche and interspecific relationship characteristics of the dominant tree species in the community. The results indicate that among the four selective cutting intensities, the tree species with the highest importance value in all cases is Abies fabri, with an average importance value of 30.29%. Additionally, Picea asperata exhibits the widest niche breadth among the tree species, with a value of 4.59. The selective thinning in this study resulted in a reduction of average species niche overlap in the community compared to the control plots. There were both positive and negative interspecies associations observed, but they were statistically insignificant. Few pairs showed significant correlations, with the positive-to-negative ratio of Pearson coefficients decreasing as the selective cutting intensity increased. The Spearman rank correlation analysis revealed a positive-to-negative ratio exceeding one for species pairs in the community under both light and heavy-cutting conditions, with no significant negative correlations observed. In summary, selective cutting disturbance can effectively increase the importance value of the dominant tree species, Abies fabri, in the community. However, it leads to a reduction in the niche breadth of all tree species present in the forest. Moderate selective cutting is considered a more suitable intensity, as it promotes the maintenance of biodiversity and yields higher forest management benefits in the mixed forest of Picea asperata and Abies fabri in Northeast China.

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 &gt;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.

Species Distribution and Patterns in a Forest-savannah Ecotone: Environmental Change and Conservation Concerns

Understanding the dynamics and patterns of biodiversity in transition forests is vital in promoting conservation and addressing environmental change issues. This work focused on elucidating the diversity, structure, and carbon potentials of a forest-savannah ecosystem. To achieve this, 8 forest plots that measured 50 m × 50 m each was set up in a forest-savannah landscape and used to identify and measure tree species ≥ 10 cm diameter at breast height (DBH measured at 130 cm). Species importance value was used to summarize the biodiversity patterns and the aboveground carbon estimates were elicited with the allometric equation. 43 species within 22 families were enumerated and the diversity was generally low (ranging from 1.82-2.5). Species such as Daniellia oliveri (Rolfe) Hutch. &amp; Dalziel, Pyrostria guinnensis Comm. ex A. Juss, Dialium guineense Willd. and Margariteria discoidea (Baill.) G.L Webster were the dominant species, and had the highest importance values of 113.06, 55.13, 28.16 and 16.95, respectively, while Allophlus africanus P. Beauv., Annona senegalensis Pers., Anthonatha macrophylla P. Beauv., Ficus capensis Thumb. and Lecaniodiscus cupanioides Planch had the least importance values of 0.16 each. Carbon estimates ranged from 16.43172-42.9298 t/Ha. Most frequent species with higher basal areas no doubt contributed much to the carbon estimates, but did not have higher capacities in storing carbon. Managing the ecosystem with more carbon-dense species was seen as a suitable strategy for addressing environmental change in the ecosystem and region.

Species niche and interspecific associations alter flora structure along a fertilization gradient in an alpine meadow of Tianshan Mountain, Xinjiang

The niche breadth, niche overlap, and interspecific associations of species in Bayinbuluke alpine meadow were investigated using ecology statistics to explore the competitive connection between the species and restricted resources in the community and the stable coexistence relationships among populations under different nitrogen addition gradients in the short term. The findings demonstrate the following. (1) The importance value of species shifted, with the fertilization samples Festuca ovina and Poa annua becoming the species with the highest importance value. Species richness fell gradually as fertilization gradient progressed, while the number of species grew initially and subsequently decreased. (2) Under different fertilization methods, the niche width and niche overlap values of the principal species changed. A positive link was found between niche width values and critical values under fertilization treatment compared with the controls. (3) By using the variance ratio approach, Pearson’s correlation, and the association coefficient test, a positive correlation was discovered among species under low fertilization gradient treatment. However, a negative correlation was found under other gradients.

Absorptive root-multidimension strategy links air temperature and species distribution in a montane forest

BackgroundAir temperature affects absorptive root traits, which are closely related to species distribution. However, it is still unclear how air temperature regulates species distribution through changes in absorptive root traits. Seven functional traits of the absorptive roots of 240 individuals of 52 species, soil properties and air temperature were measured along an elevational gradient on Mt. Fanjingshan, Tongren City, Guizhou, and then the direct and indirect effects of these controls on species distribution were detected. ResultsAbsorptive roots adapted to air temperature with two strategies. The first strategy was positively associated with the specific root area (SRA) and specific root length (SRL) and was negatively associated with the root tissue density (RTD), representing the classic root economics spectrum (RES). The second strategy was represented by the trade-off between root diameter, mycorrhizal fungi colonization (MF) and SRL, representing the collaboration gradient with “do it yourself” resource uptake ranging from “outsourcing” to mycorrhizal resource uptake. Air temperature regulated species distribution in six ways: directly reducing species importance value; indirectly increasing the species importance value by reducing soil nitrogen content or increasing soil pH by reducing soil moisture inducing absorptive roots to change from “do it yourself” resource absorption to “outsourcing” resource absorption; indirectly decreasing the species importance value by decreasing soil moisture to change from “outsourcing” resource absorption to “do it yourself” resource absorption; indirectly increasing the species importance value with increasing soil pH by reducing soil moisture resulting in absorptive root traits turning into nutrient foraging traits; and indirectly decreasing the species importance value by promoting absorptive root traits to nutrient conservation traits. ConclusionsAbsorptive root traits play a crucial role in the regulation of species distribution through multi-approaches of air temperature.

Diversity of Ferns and Lycophytes in the Mt. Malambo, Southern Philippines

This research was carried out to study the diversity and assess the conservation status and endemism of ferns and lycophytes in the Mt. Malambo, Datu Salumay, Southern Philippines. Repeated transect walks were done with 20 sampling plots delineated on the site. Specimens were collected, identified, and assessed for their conservation status and endemism. Data gathered were analyzed employing the Shannon-Weiner Index. The inventory revealed 215 species (202 species of ferns and 13 species of lycophytes) belonging to 74 genera and 23 families. Polypodiaceae, Aspleniaceae, Hymenophyllaceae, and Pteridaceae were the species-rich families collected. Asplenium nidus L., Pneumatopteris costata (Brackenr.) Holttum, and Asplenium thunbergii Kunze obtained the highest species importance values. Mt. Malambo has a diversity value of H’=1.83 which is higher compared to other mountains in Mindanao. This study reports 20 Philippine endemic and 19 threatened species of ferns and lycophytes in the area. Of these, one is critically endangered, 11 are endangered, five are vulnerable, and two are other threatened species. The presence of many threatened and endemic species in the area implies that high priority should be addressed in protecting and conserving these species of ferns and lycophytes in Mt. Malambo.

Tree Species Diversity and Stand Structure in Selected Forest Patches of Marilog Forest Reserve, Southern Philippines

&#x0D; Tree species diversity and stand structure investigations were conducted in the forest patches of Barangay Baganihan (site 1) and Mt. Malambo in Barangay Datu Salumay (site 2), Marilog District, Southern Philippines. Thirty-three 20 × 20 m plots were established at 1,197-1,345 masl in the sites. A total of 900 individuals belonging to 33 families, 43 genera, and 65 species of trees were recorded. Analyses of data revealed that the two sites could be categorised as montane forests based on the forest structure and species composition. Palaquium philippense (Perr.) C.B. Rob., Syzygium tula (Merr.) Merr., and Astrocalyx calycina (S.Vidal) Merr. obtained the highest species importance value index in site 1, while Palaquium sp., P. philippense, and Lithocarpus caudatifolius (Merr.) Rehder in site 2. Shannon-Weiner indices (H’) in sites 1 and 2 are relatively low with H’ = 1.22 and H’ = 1.38, respectively. A total of eight threatened species were recorded, viz., A. calycina as endangered; Agathis philippinensis Warb., Becarianthus pulcherrimus (Merr.) Maxw., Camellia lanceolata (Blume) Seem., Dillenia megalantha Merr., P. philippense and Shorea contorta S.Vidal as vulnerable; and Cinnamomum mercadoi S.Vidal as other threatened species. A total of 14 endemic species of trees were also recorded in the study sites. The biodiversity in the two sites is under severe threat due to the different anthropogenic disturbances. A new population of A. calycina, a monotypic genus in the Philippines, was collected and the flowers were documented for the first time after a century. The present study is significant since it would help elucidate the patterns of tree species composition and diversity in the forest patches of Barangay Baganihan and Mt. Malambo in Barangay Datu Salumay. Further, this paper adds to the rich biological diversity in Mt. Malambo by supporting its great potential as an ecotourism site.&#x0D;