Quadrat Sampling Research Articles

Characterization of carbon fluxes, stock and nutrients in the sacred forest groves and invasive vegetation stands within the human dominated landscapes of a tropical semi-arid region

In the semi-arid plains of Southern India, outside the protected area network, sacred groves forests and the barren lands invaded by Prosopis juliflora are reckoned to be the major greenery, but have homogenous and heterogeneous vegetation respectively. This study attempted to compare 50 Sacred Groves Stands (SGS) and 50 monodominant Prosopis juliflora Stands (PJS) for the functional diversity, evenness, floral diversity, carbon stock and dynamics, carbon-fixing traits, dendrochronology of trees, soil nutrient profiles, and soil erosion. Quadrat sample survey was adopted to record stand density, species richness, abundance, basal area and leaf area index; composite soil samples were collected at depths 0–30 cm for nutrient profiling (N, P, K, and OC). Photosynthesis rate (µmole co2 m2/sec), air temperature (°c), leaf intracellular co2 concentration (ppm), ambient photosynthetic active radiation (µmole m2/sec), transpiration rate (m. mole H2O m2/sec) were determined for the 51 tree species existed in SGS and PJS using Plant Photosynthesis system. Structural Equation Model (SEM) was applied to derive the carbon sequestering potential and photosynthetic efficiency of eight dominant tree species using vital input parameters, including eco-physiological, morphological, and biochemical characterization. The Revised Universal Soil Loss Equation (RUSLE) model, in conjunction with ArcGIS Pro and ArcGIS 10.3, was adopted to map soil loss. Carbon source/sink determinations inferred through Net Ecosystem Productivity (NEP) assessments showed that mature SGS potentially acted as a carbon sink (0.06 ± 0.01 g C/m2/day), while matured PJS acted as a carbon source (−0.34 ± 0.12 g C/m2/day). Soil erosion rates were significantly greater (29.5 ± 13.4 ton/ha/year) in SGS compared to PJS (7.52 ± 2.55 ton/ha/year). Of the eight selected tree species, SEM revealed that trees belonging to the family Fabaceae [Wrightia tinctoria (estimated coefficient: 1.28, p = 0.02) > Prosopis juliflora (1.22, p = 0.01) > Acacia nilotica (1.21, p = 0.03) > Albizia lebbeck (0.97, p = 0.01)] showed comparatively high carbon sequestering ability.

Plant diversity in secondary, montane grasslands – a case study of the abandoned plantations of Mariepskop Mountain, South Africa

Grasslands are one of the most threatened terrestrial ecosystem types, and montane grasslands of particular conservation concern. Despite high rates of transformation in recent decades, croplands and plantations are being abandoned in parts of many countries, creating an opportunity for conservation of montane grasslands through restoration. We report on the changes in the cover of major vegetation types (indigenous forest, grassland, and plantations) between 1935 and 2022, in an area that was intensively afforested from 1930 to 1960 and abandoned in 2000. Montane grassland at the site declined from over 50% of all landcover to below 15%, but subsequently recovered to 30% within 20 years. Many former plantations developed into secondary grassland with estimated gamma plant species richness of 231 for herbaceous species and 45 for savanna species. These are high values considering the size of the study area (4000 ha), and comparable to estimates from primary grassland sites in the broader region. However, at the scale of 1 m2 sampling quadrats, richness in the secondary grasslands was below that recorded in the last remaining patches of primary grassland at the site (means of 2.6 versus 4.7 for graminoid species, and 1.9 versus 2.9 for forbs). Some of the former Eucalyptus plantations had transformed into novel savannas dominated by fire-tolerant, resprouting trees, and may require more active restoration. Secondary grasslands such as those reported on here could potentially make a significant contribution to the conservation of montane biodiversity over the coming decades, warranting further research (both socio-economic and ecological) on the factors that lead to abandonment and promote the emerge of secondary grasslands of high diversity.

Plant communities and potential phytoremediation species for resource utilization of abandoned drilling mud

Oil and gas development produces a large amount of abandoned drilling mud, which may be a source of pollution but may also be a potential resource. A quadrat sampling method was used in the Changqing Oilfield to investigate the plant community characteristics inside and outside abandoned drilling mud pits at different completion times. The importance value of plant showed that the natural succession of plant communities in the abandoned drilling mud pool could be divided into three stages: (1) 4–8 years after the completion of the well, Leymus secalinus, Calamagrostis epigeios with the importance values of more than 100, were dominant species in the initial construction stage; (2) 9–13 years after the succession, the intense competition stage of the plant community, although the importance value of plant inside the mud pit had decreased, it was still higher than the importance value of plant outside the mud pool. The importance values of L. secalinus and Artemisia scoparia outside the mud pool were 62.5 and 52.5, while those in the mud pool were 95 and 75, respectively; (3) 23–28 years after the succession, the gradual stabilization stage of the plant community, the importance value of plant was lower than that in the mud pool. Leymus secalinus, C. epigeios and A. scoparia could be used for phytoremediation of abandoned drilling soil for their higher importance values. Changes of Shannon–Wiener index, Pielou index, Community ecological dominance and vegetation biomass showed that the mud pit was suitable for the recovery and growth of the dominant species, improved the diversity of plant communities inside the mud pit compared with the stable plant community outside the mud pit. Abandoned drilling mud increased the content of nitrogen, potassium and trace elements in plants. While the variation coefficient of heavy metal content in plants inside and outside the mud pit was large, but the content of heavy metals in plants was within the normal range. Abandoned drilling mud has the potential for resource utilization on the premise of ensuring soil quality and safety. This study provides information on the comprehensive treatment, resource utilization, disposal economics and environmental safety of abandoned drilling mud.

Gum and resin bearing dryland forests of Somali region, Southeastern Ethiopia: Diversity, structure and spatial distribution

Despite its ecological and socio-economic contributions, the lowland dry forests of Ethiopia have been experiencing severe deforestation and degradation challenges. It is, therefore, crucial to assess the status of the dry forest resources to formulate an appropriate management strategy and its sustainable utilization. This study was formulated to determine spatial distribution, species composition, structure, and regeneration of the gum and resin species bearing dry forests in the Somali regional state of Ethiopia. The recent Sentinel-2A image was procured and used to classify the area, using a supervised Random Forest Algorithm, into different land covers and vegetation types. Inside the two key vegetation types (Acacia dominated woodland and Mixed woodland), forest inventory was conducted by establishing 30 m x 30 m size quadratic sample plots. The results revealed that the study area was divided into settlement (0.2%), bare land (6.0%), undifferentiated forest (0.5%), acacia woodland (36.3%), mixed woodland (54.1%) and scrubland (2.9%). Thirty-four woody species were identified and recorded with a Shannon diversity of 3.03. The population structure showed a lack of sufficient natural regeneration. It is, therefore, imperative to say that the forest containing the gum and resin-bearing species is not replacing itself. On the other hand, the forest has the potential to produce Oleo-gum resin in various kinds and amounts. Thus, implementing appropriate restoration measures is urgent to enhance natural regeneration. Moreover, formulating sustainable utilization while creating product market of gum and resins are important considerations for the future development of the sector. Int. J. Agril. Res. Innov. Tech. 13(2): 6-13, Dec 2023

Investigating the impacts of agricultural land use on soil earthworm communities: A case study of northern Zagros Mountains of Iran

Earthworms play a crucial role in the invertebrate community of soil by contributing to the belowground biomass and biogeochemical cycle. Environmental stresses, such as human activities and land use changes, have been found to negatively affect their abundance and diversity. To investigate the impact of agricultural land use and pastures on earthworms' genetic diversity in the Northern Zagros Mountains, we used COI molecular marker and DNA barcoding approaches. We collected earthworm specimens from four farmland sites and six pastures and assessed the abundance and species composition of earthworm communities across the two land uses using quadrat sampling. Using the barcoding method, we identified 13 molecular operational taxonomic units (MOTUs) among the captured earthworms. Our results showed that the number of total MOTUs, density, and earthworm communities differed significantly between the two land uses. We also found that pastures had more abundant earthworms, while farmlands had greater diversity. The diversity of OTUs in the Lumbricidae family was dominant in the agricultural system. Overall, the population of invasive earthworm species in cultivation systems is influenced by chemical inputs and organic materials from plant residues, cover crops, manure, or organic fertilizers. Given the rapid rate of land use change worldwide, especially in Iran, it is crucial to understand the impact of disturbances on earthworms.

Macroalgae diversity and its relationship with environmental conditions in polluted waters of Seribu Islands, Jakarta Bay, Indonesia

Abstract. Handayani S, Widhiono I, Widyartini DS. 2023. Macroalgae diversity and its relationship with environmental conditions in polluted waters of Seribu Islands, Jakarta Bay, Indonesia. Biodiversitas 24: 6291-6298. Macroalgae are one of the important marine primary producers because they support the life of other organisms at a higher trophic level in aquatic ecosystems. This study aimed to determine the species diversity and composition of macroalgae and its relationship with local aquatic environmental conditions. This research was conducted in Seribu Islands, Jakarta Bay, and consisted of Pramuka Island, Semak Daun Island, Kotok Besar Island, Karang Bongkok Island, Kongsi Island, and Pari Island as sampling sites. This research used the transect method with quadratic sampling and the data was analyzed using the Shannon-Wiener Diversity Index, Dominance Index, and Evenness. Diversity parameter calculations were carried out using PAST4.0 software. The relationship between diversity and water quality was analyzed using PCA software. Across the six sampling sites, there were 41 species of macroalgae belonging to 3 divisions, namely Chlorophyta (19 species), Phaeophyta/Ochrophyta (10 species), and Rhodophyta (12 species). The species richness among islands showed that Karang Bongkok Island had the highest species with 28 species and the lowest was Semak Daun Island and Kongsi Island with only 15 species. The Diversity Index was the highest in Karang Bongkok Island with 2.679 and the lowest was in Kongsi Island with 1.907. The species with the largest number of individuals were Halimeda macroloba with 930 individuals, followed by Sargassum binderi with 648 individuals, and Corallina officinalis. with 257 individuals. The diversity of macroalgae species on the six islands is classified as moderate and can be used as an indicator of marine ecosystems. Physicochemical parameters that affect macroalgae diversity in the Seribu Islands waters are temperature, depth, currents, salinity, Total Dissolved Solids (TDS), pH, Dissolved Oxygen (DO), Cu, and Phosphate. The finding of this study implies that despite the high pollution in Seribu Islands waters, it is still good for the growth of macroalgae.

Sistemas aéreos no tripulados y sensores remotos pasivos para clasificar microecosistemas de pastizales alto andinos

Pastures are the fodder base for camelid and sheep production in the southern Peruvian Andes, where 80% of alpacas and 15 % of sheep live, which requires better land management and grazing programs through the classification of microecosystems. The objective of this study was to classify the microecosystems based on the grasslands of the Kayra Agronomic Center in the Region of Cusco using unmanned aerial vehicles and remote sensors. To do this, traditional evaluation and estimation methods such as modified Parker and quadrat sampling, were combined with biomass classification and estimation methods supported by multispectral images. This was done using 5 m RapidEye satellite images, and multispectral orthophotographs acquired with a Micasense sensor transported by a Matrix 300 RTK Drone with 10 cm pixels. Processing was performed by Pix 4D version 4.7.5 photogrammetry software, and ENVI and ArcGIS 10.3 image processing software. An algorithm designed in the R programming language was used to estimate the biomass. The results show three life zones, three climatic zones, four ecosystems, and four plant communities with eleven dominant species. The condition of the grasslands evaluated was regular with a tendency to poor and a carrying capacity of 0.3 UV.ha-1.year-1; 0.83 UO.ha-1.year-1 and 1.11UA.ha-1.year-1. The use of remote sensors made it possible to classify grasslands quickly and efficiently.

Identification and Analysis of Biodiversity in the Mount Tidar Botanical Gardens

Existing biodiversity has potential if it can be managed optimally and sustainably. Since January 2020, Mount Tidar has officially changed its status from an urban forest to a botanical garden. This change in status has an impact on nature conservation. The purpose of this study was to identify and determine the level of diversity in the Mount Tidar Botanical Garden (MTBG). The methods used in this study are quadratic sampling, plotting, and survey techniques. Data analysis using reference calculation of Shanon Weiner index, evenness index, Simpson dominance, and Margalef species richness index. The results showed the discovery of 121 species with a total vegetation of 5,912 individuals. Then Shanon Weiner’s diversity calculation got a medium value (H’ 2.306), evenness index at the medium level (E 0.481), Simpson dominance index with a high value (IDS 0.917), and Margalef species richness with a high value around (R 13.82). So that the value of the diversity calculation is the basis that the identification and diversity of vegetation in MTBG is at a stage of rapid development at medium to high levels. This data can be a reference for managers to make it easier to assess the Sustainable Planning and management system of MTBG conservation areas.

Study on Cascade Density of the Impeller Based on Response Surface Analysis

In order to improve the cavitation performance of hydraulic machinery in the design stage, the response surface analysis method is used to study the influence of cascade density on the hydraulic characteristics and cavitation characteristics of a three-dimensional rotating hydrofoil. For this method, an axial flow impeller with a specific speed of 750 is selected as the experimental object. Nine groups of three-dimensional rotating hydrofoils with different cascade densities were designed by the D-optimal quadratic sampling method. The impeller and guide vane were structured and meshed by TurboGrid. The inlet and outlet extension sections were structured and meshed by ICEM. Grid independence analysis was carried out. The hydraulic characteristics and cavitation characteristics of nine groups of hydrofoils were calculated by CFD numerical simulation. The calculation results of nine groups of schemes were analyzed from three angles of external characteristics, flow pattern and cavitation performance, and the better schemes under each analysis angle were obtained. By means of response surface analysis, more external characteristics and cavitation characteristics of different cascade densities will be filled. Finally, combined with the response target, the influence of cascade density on each target is analyzed and the comprehensive selection range of hub and shroud is given. This method can improve the rationality of sampling, and select a more suitable range of cascade density by designing fewer impellers.

Population Structure and Regeneration Dynamics of Tree Species in Banj Oak Forests of Tehri Garhwal, Western Himalaya

Forest regeneration is a natural process of forest resource reclamation through production of young ones (saplings and seedlings). Tree species show variable regeneration potential in different associations and response to natural and man-made factors. Banj oak (Quercus leucotrichophora A. Camus), one of the important forest forming tree species in western montane Himalaya, is facing regeneration failure in different locations. The present study attempted to assess the population structure and regeneration of Q. leucotrichophora and associated tree species in five different stands (sites) of a less explored region (Tehri Garhwal, Uttarakhand, Western Himalaya). To investigate the phytosociological attributes, ten sampling quadrats (400 m2) were laid in random sampling manner in each forest stand for surveying tree layer, 2 sub-quadrats (25 m2) for saplings, and 5 sub-quadrats (1 m2) for seedlings in each sampling quadrat. Among the studied forest stands, tree species richness ranged 8 to 11 (8.8±1.3), total stem density (ind/ha) 750 to 950 (846±85.6), and total basal area (m2/ha) 18.68 to 29.18 (24.1±3.9). Based on abundance data the banj oak showed ‘good’ regeneration statuses (density of seedling > saplings > adult trees) in all forests. The distribution of adult tree individuals into different size classes (DBH classes) also indicate ‘good’ regeneration pattern (higher density in lower size classes and gradual decrease in density towards higher classes or forming a reverse J-shaped pattern). However, majority of the banj oak associated species (e.g. Prunus cerasoides, Pyrus pashia, Rhododendron arboreum, etc.) represented ‘fair’ regeneration statuses (seedlings > or ≤ saplings ≤ adult trees). Overall, the results of this study shed light on the positive prospects for Q. leucotrichophora regeneration and the importance of sustainable coexistence between human communities and these vital forest ecosystems.

Sphagnum cultivation sites as habitat for beetles (Coleoptera) and the effect of vegetation structure on species occurrence and abundance

The cultivation of peat mosses (‘Sphagnum farming’) is a new wet and climate-friendly agricultural use of degraded bog sites. However, it is largely unknown to what extent these surrogate habitats are used by bog fauna. This study investigated the potential of Sphagnum cultivation sites as surrogate habitats for beetles and evaluated the relationship between the vegetation structure and the occurrence of beetle species. In 2017 and 2018, comparative surveys were carried out at different sub-areas of two Sphagnum cultivation sites and one near-natural bog. Beetles living in and on the upper Sphagnum layer were studied by manually extracting quadrat samples. Vegetation surveys were conducted in the same quadrats to analyze the occurrence of beetle species based on vegetation parameters. We collected 926 individuals of beetles belonging to 89 species out of 17 families. At the different sections of the cultivation sites, 8–16 bog-typical beetle species were found, while at the sub-areas of the near-natural bog, there were 15 and 19 bog-typical species, respectively. The statistical analyses showed that vegetation structure influenced the numbers of beetle species and individuals at both the cultivation and near-natural sites.Implications for insect conservationA dense and high Sphagnum carpet is a fundamental habitat structure for the beetle fauna of cultivation sites, while vascular plants initially help to create habitat structures on bare peat. Conversely, if the vascular plants overgrow and shade the Sphagnum, this can have a negative effect on bog-typical beetle species, as shown at the near-natural site.

Inferring single- and multi-species distributional aggregation using quadrat sampling

Ecologists often employ cost-effective strategies such as quadrat sampling for field-based biodiversity assessments. While the negative binomial distribution (NBD) is widely used to characterize quadrat sampling-derived biodiversity data in single-species settings, an equivalent model for accurately modeling community-level distributional aggregation levels, especially for quadrat sampling data, is still lacking. Here, we recommend the application of symmetric Dirichlet-multinomial (SDM) distribution to characterize aggregation patterns for single- or multi-species. Theoretically, we proved that the likelihood formulae for the SDM and NBD models were nearly equivalent, and consequently, the shape parameters of both models were almost identical. Numerical simulations demonstrated that the SDM model consistently outperformed the NBD model except for cases with large numbers of small-sized quadrats. Empirical tests using the SDM model showed that trees of the forest plot on the Barro Colorado Island shifted from aggregated to even and then back to aggregated again from 1982 to 2015 because of stand competition dynamics driven by tree mortality and recruitment balance. Functionally, the aggregation parameter of the SDM model reflects more purely this biological mechanism-driven aggregation trend, whereas classical nonparametric aggregation metrics failed. In summary, the proposed SDM can be an indispensable tool for inferring species- and community-level distributional aggregation patterns.

Species of associated bryophytes and their effects on the yield and quality of Dendrobium nobile

BackgroundDendrobium nobile has unique growth environment requirements, and unstable yields and high management costs are the key factors restricting the development of its imitation wild cultivation industry. The present study explored the effects of different associated bryophyte species on the yield and quality of D. nobile to clarify the dominant bryophyte species associated with D. nobile and to provide a scientific basis for the rational cultivation and quality evaluation of D. nobile.ResultsThe growth of D. nobile was closely related to the microenvironment of the Danxia stone, and the different associated bryophytes had different effects on D. nobile growth. There was a rich variety of bryophytes associated with D. nobile, with a total of 15 families, 24 genera and 31 species of bryophytes identified in the study area, including 13 families, 22 genera and 29 species of mosses and 2 families, 2 genera and 2 species of liverworts, and mosses predominated in the association with D. nobile. Usually, 3–9 species of bryophytes were growing in association with D. nobile, among which associations of 5–6 bryophytes species were more common, and the bryophytes associated with D. nobile were only related to the species to which they belonged. The dry matter accumulation, quality and mineral content of D. nobile differed significantly among different bryophyte species. The coefficients of variation of dry matter accumulation, dendrobine content and content of 11 mineral elements of D. nobile in the 35 sample quadrats were 25.00%, 21.08%, and 11.33–57.96%, respectively. The biomass, dendrobine content and mineral content of D. nobile were analysed by principal component analysis (PCA) and membership function. The results showed that each evaluation method initially screened Trachycystis microphylla and Leucobryum juniperoideum as the dominant associated bryophytes in the preliminary identification analysis, and the frequency of occurrence and coverage of the two bryophytes were significantly higher than those of the remaining bryophytes. It was determined that T. microphylla and L. juniperoideum were the dominant associated bryophytes.ConclusionsThere is a rich variety of bryophytes associated with D. nobile. The yield and quality of D. nobile differed significantly among different bryophyte species. T. microphylla and L. juniperoideum were the dominant associated bryophytes, and were the two bryophytes associated with D. nobile through mixed growth.

Changes in Lactic Acid Concentrations in Culture Media and its Implications in the Inhibition of Fungal Development

In the following research, a novel antifungal culture method was discussed with the aim of developing bacterial culture media in which fungal growth is inhibited and bacterial growth is stimulated. This technique is based on the use of lactic acid as an antifungal agent, due to its capacity to neutralise the electrochemical gradient of fungal cell membranes, thus inhibiting their development. Based on this principle, the Minimum Inhibitory Concentration (MIC) of lactic acid in the culture media was Investigated by changing its concentrations. After the preparation of the solutions, microbiological seeding was carried out in the different experimental groups. Data were collected using a quadrat sampling technique for subsequent statistical analysis using the T-test coefficient. As a result, the minimum inhibitory concentration of lactic acid was found to be 20%, where fungal growth was inhibited, and bacterial growth was stimulated.

Traditional ploughing is critical to the conservation of threatened plants in Mediterranean olive groves

Arable plant diversity has been dramatically declining due to agriculture intensification, with several arable species currently included in national Red Lists. This is particularly relevant in the case of plant communities of the traditional Mediterranean agricultural systems. Despite the current knowledge about the factors affecting this diversity, it is not clear how these communities, which have likely evolved under the pressure of ploughing for millennia, depend on this regular soil disturbance. This is an important issue nowadays, because current management practices focused on the conservation of the ground vegetation cover, to protect soil and other biological groups, often exclude ploughing. In this paper, we test the hypothesis that traditional ploughing is favourable to more specialist arable plants, predictably more dependent on the regular soil disturbance. We address this issue in a Mediterranean agricultural system, the traditional olive groves of Southern Portugal, which is characterized by the annual ploughing of soil. A total of 90 plots containing 1350 sampling quadrats were sampled, and all plant species identified. We categorized plants in four target groups of conservation interest, and then used a joint species distribution model to model their occurrence in relation to three management practices: ploughing, cultivation and low-intensity grazing, using abandoned olive groves as reference level. Results suggest that ploughing is a key factor for the maintenance of arable plant diversity. Ploughing had a positive effect on the occurrence of rare arable plants, archaeophytes and on several Red listed species. In order to conserve these high value plant communities and endangered plant species, we recommend incentivizing ploughing using reduced tillage techniques (e.g. chisel ploughing) on these traditional Mediterranean agricultural systems.

Ecological Assessment of the Role of Mangrove Trees in Carbon Sequestration and Biodiversity In Karimunjawa National Park Indonesia

Mangrove ecosystem has an important role in reducing carbon in the environment. There has been massive conversion of mangrove area into ponds and buildings in the current period. Therefore, the species diversity and carbon sequestration capacity of the mangrove ecosystem must be evaluated to monitor its function. This research aims to evaluate the species diversity and the sequestered carbon in the mangrove ecosystem of Karimunjawa National Park (KNP), Indonesia. The species analysis in the 3 research sites, 9 transects, and 27 plots (10 m × 10 m) that was obtained using the quadrat sampling method. Allometric equations, Shannon–Wiener, and evenness indices were used to estimate the standing biomass and carbon, species diversity, and distribution, respectively. The sediment samples were obtained at a depth of 100 cm and divided into three depths, namely, 0–33, 34–67, and 68–100 cm. The carbon content of mangrove sediments was analyzed in the laboratory using the Walkley–Black method. The results revealed that mangroves in the KNP have moderate diversity and even distribution. The estimated carbon in the mangrove stand was 146.22 t C ha–1 and the estimated carbon stock in the sediment was around 360.61 t C ha–1. Although the mangrove ecosystem in Karimunjawa National Park is still in a stable condition, it is necessary to monitor its changes due to the anthropogenic activities.

Species Diversity and Carbon Stock of Mangrove in Guiuan, Eastern Samar, Philippines

Mangrove forests sequester substantial amounts of atmospheric carbon dioxide, store carbon in their biomass, and have the highest carbon pool of any forest. The Philippines is one of the mangrove-rich countries, with almost 1.9% of the global mangroves. No current published works on mangroves exist in Guiuan, Eastern Samar, Philippines. This study utilized a non-destructive technique through quadrat sampling to identify and measure mangroves’ biodiversity and carbon stock. The allometric equation was applied to quantify the carbon stock and Shannon-Wiener diversity index to determine the biodiversity. Twelve species were identified from the 36 sampling plot with 10 × 10 meter. Results showed the mean species evenness of 0.28 and the Shannon-Wiener diversity value of 0.92, indicating very low diversity. The overall aboveground, belowground, total carbon stock, and CO2 sequestration of 209 t/ha, 76 t/ha, 157 t/ha, and 575 CO2 t/ha, respectively. The test revealed that comparing the six barangays regarding species diversity and carbon stocks gives no statistically significant difference of 0.032 and 0.046, respectively. Considering the estimated carbon stock and CO2 equivalent accounted from the tree biomass, the mangrove stands in Guiuan have the potential to store and sequester a large amount of carbon dioxide.

Effect of short-term grazing exclusion on herbage species composition, dry matter productivity, and chemical composition of subtropical grasslands

Abstract Grazing exclusion (GE) is a useful management technique for restoring degraded grasslands. The herbage mass productivity and chemical makeup in the grazing-excluded subtropical grassland environment has, however, received little attention. A subtropical riverine grassland was selected to determine the effect of GE on herbage mass productivity and chemical composition in Nepal. In three successive harvesting times from September to November 2020, the herbage was sampled along the six randomly selected transects of 100 m length and at two treatments (GA: Grazing-allowed and GE: Grazing-excluded plots) at three different times of harvest from a 1,000-ha grassland. A total of 108 herbage cut samples were collected from the individual 1 m × 1 m quadrats at the three harvests, respectively, from the GA and GE plots. Fences were used to maintain the GE plots to avoid grazing to prevent the vegetation altered by grazing. Day before herbage sampling, the functional groups, cover-abundance within the sampling quadrats were investigated. By cutting the fresh herbage 5 cm above the ground and subjecting it to oven drying for laboratory examination, the herbage mass productivity within each quadrat was measured. Using established laboratory procedures, the chemical analysis of herbage was evaluated for its proximate, fibre, and mineral contents. The results of the study demonstrated that GE significantly increased grass species than other-forbs, other-graminoids, and legumes, respectively, and increased dry matter productivity, which could be seen by an increase in leaf stem ratio, tiller productivity, increased coarseness (fibrous content), total ash, calcium (Ca), and phosphorus (P), but with a decreased nonstructural carbohydrate, and the concentrations of ether extract and crude protein. Research results also confirmed that GE increases herbages’ fibrousness and productivity, though the herbage quality, intake, and digestibility decline. It further demonstrates that grazing is a crucial biological component for maintaining pasture quality in subtropical grasslands and that managing grasslands through livestock grazing would make grasslands more stable and nutrient-enriched. The findings of this study can be useful in the long-term monitoring of grazing livestock in the subtropical grasslands when considering further investigations with the multiple factors in future.

Diversity of Molluscs Associated with Mangroves on The Gerupuk Beach in Central Lombok in 2023

Mangrove ecosystems have an important role in coastal areas. One of the roles of mangroves is to protect the shoreline and prevent seawater intrusion. Molluscs are one of the mangrove association biota whose lives are influenced by the presence of mangrove forests. Therefore, the purpose of this study was to determine the diversity of molluscs and the relationship between mangrove density and limiting molluscs to the coastal mangrove area of ​​Gerupuk Beach, Central Lombok. Sampling of molluscs used the quadrate sampling method with purposive sampling by taking into account the mangrove species found in the observation plots. The data obtained were then analyzed with the charisma index, associations, and Pearson's correlation coefficient. The results of this study obtained 13 species of Molluscs consisting of 12 species of the Gastropod family and 1 species of the Bivalvia family. The Brachyura diversity index at the research station was moderate with a value between 1.48–1.88. Furthermore, there were 8 species of Molluscs associated with 4 species of mangrove from 13 species of Molluscs found. The linear regression equation y = 0.1429x + 0.0007 with a Pearson correlation coefficient (r) of 0.57 indicates a strong relationship between the independent variable (x) mangrove density and the dependent variable (y) exposure to molluscs. The conclusion of this study is that the diversity of molluscs in the mangrove area of ​​Gerupuk Beach is included in the moderate category and there is a significant relationship between mangrove density and mollusk attractions.

Species richness and diversity of pteridophytes along the vicinity of Mt. Kibuwa, Impalutao, Impasug-ong, Bukidnon

Bukidnon being in a tropical country is composed of the richest and most diverse ecosystems. Mt. Kibuwa, the location of this study exhibits this diversity through its vast vegetation of pteridophytes or ferns along its area. Ferns are important ecological indicators since they can live in different niches and they have a variety of commercial uses—thus, there is a need for these species to be conserved. This study assessed the species richness and diversity of ferns along the vicinity of Mt. Kibuwa, Impalutao, Impasug-ong, Bukidnon to heighten up ecological conservation efforts within the area. In this study, Mt. Kibuwa was divided in to ten (10) sampling quadrats measuring 10m by 10m. The researchers collected seven (7) fern species and were confirmed and identified by the Central Mindanao University- Center for Biodiversity Research and Extension in Mindanao (CMU-CEBREM) as: Sphenomeris chusana, Pteridium aquilinum, Pityrogramma calomelanos, Culcita sp., Cyathea dregei, Nephroliphios exaltata, and Dricanopteris linearis. Using Menhinnick’s index of species richness and Shannon-Weinner species diversity index, results show that the species richness in all the sampling sites are closely similar with Pteridium aquilinum being the richest species and Site 1 on the lower elevation being the richest site. In terms of species diversity, this research concludes that Mt. Kibuwa has a good diversity of fern species and can be promoted for high ecological conservation and protection.