Vegetation Characteristics Research Articles

Comprehensive Assessment of the Risk of Symptomatic Embolism in Patients With Infective Endocarditis.

Echocardiographic evaluation of vegetations is crucial in infective endocarditis (IE). Although several studies have noted a link between larger vegetations and an increased risk of embolization, a more comprehensive evaluation of vegetation characteristics in a contemporary cohort has not been conducted. Our study aimed to define the short-term risk of symptomatic embolization in patients with IE. The Mayo Clinic IE registry was screened to identify patients from 2015 to 2021 who had undergone transesophageal echocardiography. Multivariable subdistribution hazards regression analysis was used to identify factors associated with the cumulative incidence of symptomatic embolism over 30 days accounting for the competing risk of death. Overall, 779 patients with IE were included, of whom 517 (66.4%) were men, median age was 65.0 (interquartile range, 52.9-74.8) years, and 89.3% were White. In total, 234 patients had a symptomatic embolic event, a 30-day cumulative incidence of 30.2%. In multivariable analysis, a highly mobile vegetation was the strongest predictor of embolism (P<0.001). Vegetation length with interaction of IE type was also associated with embolic risk (P<0.001), with a stronger effect in native valve IE (P interaction=0.001). Other associated factors included multiple vegetations, younger age, and Staphylococcus aureus. A nomogram that incorporated these factors was constructed to facilitate the prediction of embolic risk. Highly mobile, larger vegetations are associated with embolic events. Embolic risk could be assessed by evaluating length as a continuous variable, alongside other echocardiographic findings, using a newly developed scoring tool; external validation is warranted.

Pleistocene Refugia Inferred from Molecular Evidence in a Forest-Dwelling Harvestman (Arachnida, Opiliones, Gonyleptidae) Support a Biogeographic Split in Subtropical Argentina.

This paper addresses the population genetic structure of the forest-dwelling gonyleptid Geraeocormobius sylvarum (Arachnida, Opiliones). Phylogeographic analyses using cytochrome oxidase subunit I (COI) were conducted on 186 individuals from 43 localities in Argentina and Paraguay, arranged into nine operational sectors and defined upon geographic and vegetation features. Given the current environmental uniformity, it was aimed to assess whether molecular fingerprints of G. sylvarum correlate with Pleistocene fragmentation events, inferred through forest contraction/expansion cycles. The network of 87 haplotypes displayed an unstructured pattern; 75 were found in unique localities (54 on single individuals), with most haplotypes restricted to a single operational sector. The calibrated phylogenetic tree revealed significant admixture, with each clade mainly related to one operational sector. Results suggest multiple fragmentation events; most COI diversity arose in the Late Pleistocene/Early Holocene; recent and relict lineages coexist at a few sites. Banks of major rivers (Paraná and Uruguay) in Misiones Province may have served as main refuge areas, with dispersal within each basin being frequent but sporadic across the watershed divide, keeping basins separated for long periods. The split of the Misiones opiliogeographical area into two sectors corresponding to the major basins is proposed.

Classification and Monitoring of Salt Marsh Vegetation in the Yellow River Delta Based on Multi-Source Remote Sensing Data Fusion.

Salt marsh vegetation in the Yellow River Delta, including Phragmites australis (P. australis), Suaeda salsa (S. salsa), and Tamarix chinensis (T. chinensis), is essential for the stability of wetland ecosystems. In recent years, salt marsh vegetation has experienced severe degradation, which is primarily due to invasive species and human activities. Therefore, the accurate monitoring of the spatial distribution of these vegetation types is critical for the ecological protection and restoration of the Yellow River Delta. This study proposes a multi-source remote sensing data fusion method based on Sentinel-1 and Sentinel-2 imagery, integrating the temporal characteristics of optical and SAR (synthetic aperture radar) data for the classification mapping of salt marsh vegetation in the Yellow River Delta. Phenological and polarization features were extracted to capture vegetation characteristics. A random forest algorithm was then applied to evaluate the impact of different feature combinations on classification accuracy. Combining optical and SAR time-series data significantly enhanced classification accuracy, particularly in differentiating P. australis, S. salsa, and T. chinensis. The integration of phenological features, polarization ratio, and polarization difference achieved a classification accuracy of 93.51% with a Kappa coefficient of 0.917, outperforming the use of individual data sources.

Visualization microclimate scenarios of Classical Chinese Garden in Suzhou, China

The intensification of urbanization worldwide, particularly in China, has led to significant challenges in maintaining sustainable urban environments, primarily due to the Urban Heat Island (UHI) effect. This effect exacerbates urban thermal stress, leading to increased energy consumption, poor air quality, and heightened health risks. In response, urban green spaces are recognized for their role in ameliorating urban heat and enhancing environmental resilience. This paper has studied the microclimate regulation effects of three representative classical gardens in Suzhou—the Humble Administrator’s Garden, the Lingering Garden and the Canglang Pavilion. It aims to explore the specific impacts of water bodies, vegetation and architectural features on the air temperature and relative humidity within the gardens. With the help of Geographic Information System (GIS) technology and the Inverse Distance Weighted (IDW) spatial interpolation method, this study has analyzed the microclimate regulation mechanisms in the designs of these traditional gardens. The results show that water bodies and lush vegetation have significant effects on reducing temperature and increasing humidity, while the architectural structures and rocks have affected the distribution and retention of heat to some extent. These findings not only enrich our understanding of the role of the design principles of classical gardens in climate adaptability but also provide important theoretical basis and practical guidance for the design of modern urban parks and the planning of sustainable urban environments. In addition, the study highlights GIS-based spatial interpolation as a valuable tool for visualizing and optimizing thermal comfort in urban landscapes, providing insights for developing resilient urban green spaces.

Morphometric Investigation of a Species Complex in Mimosa Section Batocaulon Series Cordistipulae (Leguminosae, Caesalpinioideae).

Mimosa series Cordistipulae was created by Barneby in 1991, embracing species diagnosed by their small subshrubby habit and the presence of gland-tipped setae and trimerous flowers. Most species are endemic to Northeastern Brazil, and some possess characters deemed diagnostic which nonetheless overlap, making species identification difficult. Our study aimed to test species circumscriptions and sets of characters that could be applied to unequivocally distinguish the species. Twelve populations (225 individuals) were collected at nine localities, encompassing the Brazilian vegetation types Caatinga, Campos Rupestres and Restinga. Linear measurements of 38 floral and vegetative characters were measured and analyzed using Canonical Variate Analysis and cluster analysis. The first two canonical axes explained 41.4% and 18.9% of the variation and separated two populations of the group recently described as a new species. Vegetative characters are more informative for species delimitation than flower characters, and most groups are distinguished primarily by the number of pinnae pairs, number of leaflets per pinna and length of the leaf rachis. The species displaying the highest morphological similarity are M. misera, M. leptantha and M. minarum. The traditional morphometric approach was capable of objectively dealing with a type of variation that would be difficult to interpret by purely examining herbarium specimens.

Improving Forest Canopy Height Mapping in Wuyishan National Park Through Calibration of ZiYuan-3 Stereo Imagery Using Limited Unmanned Aerial Vehicle LiDAR Data

Forest canopy height (FCH) is a critical parameter for forest management and ecosystem modeling, but there is a lack of accurate FCH distribution in large areas. To address this issue, this study selected Wuyishan National Park in China as a case study to explore the calibration method for mapping FCH in a complex subtropical mountainous region based on ZiYuan-3 (ZY3) stereo imagery and limited Unmanned Aerial Vehicle (UAV) LiDAR data. Pearson’s correlation analysis, Categorical Boosting (CatBoost) feature importance analysis, and causal effect analysis were used to examine major factors causing extraction errors of digital surface model (DSM) data from ZY3 stereo imagery. Different machine learning algorithms were compared and used to calibrate the DSM and FCH results. The results indicate that the DSM extraction accuracy based on ZY3 stereo imagery is primarily influenced by slope aspect, elevation, and vegetation characteristics. These influences were particularly notable in areas with a complex topography and dense vegetation coverage. A Bayesian-optimized CatBoost model with directly calibrating the original FCH (the difference between the DSM from ZY3 and high-precision digital elevation model (DEM) data) demonstrated the best prediction performance. This model produced the FCH map at a 4 m spatial resolution, the root mean square error (RMSE) was reduced from 6.47 m based on initial stereo imagery to 3.99 m after calibration, and the relative RMSE (rRMSE) was reduced from 36.52% to 22.53%. The study demonstrates the feasibility of using ZY3 imagery for regional forest canopy height mapping and confirms the superior performance of using the CatBoost algorithm in enhancing FCH calibration accuracy. These findings provide valuable insights into the multidimensional impacts of key environmental factors on FCH extraction, supporting precise forest monitoring and carbon stock assessment in complex terrains in subtropical regions.

Estimation Model for Cotton Canopy Structure Parameters Based on Spectral Vegetation Index.

The spectral vegetation indices derived from remote sensing data provide a detailed spectral analysis for assessing vegetation characteristics. This study investigated the relationship between cotton yield and canopy spectral indices to develop yield estimation models. Spectral reflectance data were collected at various growth stages using an ASD FieldSpec Pro VNIR 2500 spectrometer. Six prediction models were developed using spectral vegetation indices, including the Normalized Difference Vegetation Index (NDVI) and Ratio Vegetation Index (RVI), to estimate the Leaf Area Index (LAI) and above-ground biomass. For LAI estimation using the NDVI, the power function model (y = 10.083x11.298) demonstrated higher precision, with a multiple correlation coefficient of R2 = 0.8184 and the smallest root mean square error (RMSE = 0.3613). These results confirm the strong predictive capacity of NDVI for LAI, with the power function model offering the best estimation accuracy. In estimating above-ground biomass using RVI, the power function model of y = 6.5218x1.33917 achieved the higher correlation (R2 = 0.8851) for fresh biomass with an RMSE of 0.1033, making it the most accurate. For dry biomass, the exponential function model (y = 9.1565 × 10-5∙exp(1.1146x)) was the most precise, achieving an R2 value of 0.8456 and the lowest RMSE value of 0.0076. These findings highlight the potential of spectral remote sensing for accurately predicting cotton canopy structural parameters and biomass weights. By integrating spectral analysis techniques with remote sensing, this research offers valuable insights for precision cotton planting and field management, enabling optimized agricultural practices and enhanced vegetation health monitoring.

Investigating the impact of oligo-chitosan on the growth dynamics and yield traits of Oryza sativa L. 'BRRI dhan29' under subtropical conditions.

Reducing the harmful chemical use along with obtaining potential yield in field is a worth exploring practice in rice cultivation. To mitigate the prevailing yield gap, the current study was designed to evaluate the effect of chitosan in improving growth, yield contributing characters and yield of rice. The experiment comprised eight different treatments viz. control (no fertilizer and Chitosan) (T0), conventional method (with fertilizers) (T1), conventional method with foliar spray of 100ppm chitosan solution (T2), conventional method with foliar spray of 300ppm chitosan solution (T3), conventional method with foliar spray of 500ppm chitosan solution (T4), only foliar spray of 100ppm chitosan solution (T5), only foliar spray of 300ppm chitosan solution (T6), and only foliar spray of 500ppm chitosan solution (T7). The experiment was laid out in a completely randomized block design containing three replications. Data on different vegetative and yield contributing characters were recorded to evaluate the treatments effectiveness in improving rice yield. Different growth and yield contributing characters showed significant improvement after applying chitosan in addition to the conventional production system. The conventional method with foliar spray of 500ppm chitosan solution had a greater positive effect on yield contributing characters and yield. In vegetative characters, the highest plant height became (87.3cm), number of tiller hill-1 (13.7), Total dry matter (12.9), leaf area index (1.35), and chlorophyll content (57.73). On the basis of assessed treatments in yield contributing characters and yield, the highest plant height was (91.8cm), no. of grains panicle-1 (145.29), grain yield (6.37tha-1), straw yield (6.47tha-1). Results showed that the conventional method with foliar spray of different concentration of chitosan solution was able to increase yield up to 26% in comparison to the conventional method. Overall, our findings suggest that additional foliar spray of chitosan with previously recommended cultivation practice can increase the yield per unit area and offers promising technology to achieve potential yield in farmer's field.

Vertical mass exchange in wetland flows with shear layers

Vertical mass exchange hugely changes the solute distribution with the effects of shear layers and multiple-scale turbulent vortices, and then impacts the effectiveness of wetlands in purifying eutrophic water bodies. This study aims to investigate vertical mass exchange mechanisms in wetland systems and to provide theoretical guidance for optimizing the purification efficiency of wetland water quality. We simulate solute diffusion behaviors originating from a continuous point source with vegetated shear layers and bed absorptions through the adopted numerical simulation method, random walk method. The simulated results mainly contributed to three findings: (1) Vegetation features (density and height) inhibit solute diffusion, resulting in a prolonged steady time required for the cross-sectional concentration to reach equilibrium. (2) There is a threshold for the bed absorption probabilities to impact near-bed concentration distribution, that is the 10% absorption probability, over which the variation of bed absorption has few effects on the solute concentration. (3) The shear layer at the top of vegetation promotes vertical mass exchange while preventing solutes above the wake zone from being absorbed by the bed. In practice, the dual effects of submerged vegetation on vertical mass exchange should be comprehensively considered to ensure the effective functioning of wetland ecosystems.

Shifts in the ecological drivers influence the response of tree and soil carbon dynamics in central Himalayan forests.

Understanding and regulating global carbon relies crucially on comprehending the components and services of forest ecosystems. In particular, interactions that govern carbon storage in trees, soil, and microbes, driven by factors like vegetation structure, function, and soil characteristics, remain poorly understood, especially in the central Himalayas. To address this gap, we investigated carbon storage in tree aboveground biomass, root biomass, and soil across different vegetation types. We also examined how vegetation parameters {vegetation diversity (H'), diameter at breast height (DBH), basal area (BA), and biomass}, and soil characteristics {bulk density (BD), moisture (Mo), pH, and total nitrogen (N)} might influence forest carbon storage. Our study, based on 14 plots (0.1ha each) spanning four distinct vegetation types {Sal forest (SF, 3), Chir-pine forest (PF, 4), Nepalese-alder forest (AF, 3), and Banj-oak forest (OF, 4)} in the central Himalaya, revealed several key insights. Tree carbon storage ranged from ∼79 to 261MgC ha-1, accounting for 41-65% of forest carbon storage, while soil carbon storage ranged from ∼28 to 69MgC ha-1, contributing 35-58%. These values varied with vegetation types and were influenced by the vegetation and soil characteristics associated with each forest type. Important contributors to tree and soil carbon storage included soil Mo, N, and vegetation structural diversity (H', BA), explaining 8-64 % of the variation. Path analysis indicated that increased vegetation diversity, soil properties, and conservative traits (fine roots and leaves) strongly influence tree and soil carbon storage. The study highlights the potential complex system to optimizing carbon storage in natural forest ecosystems, offering valuable insight for managing carbon sinks. Further research is needed to fully understand ecosystem responses to carbon storage across different forest habitats and different spatial-temporal scales.

Updated checklist of Angiosperms in an exceptional area of the Serra do Teixeira National Park (PARNA), Paraíba, Brazil

The Caatinga is the largest Seasonally Dry Tropical Forest (SDTF) in South America with diverse geomorphological features. The “altitude marshes”, exceptional areas with altitudes above 700 m that were established in the humid mountains of the Caatinga, shelter vegetation characteristic of other phytogeographic domains. Despite the importance of these areas for the Brazilian semi-arid region, several of them still remain unknown, or little known, floristically. This study aims to update the floristic inventory of angiosperms in the recently created Serra do Teixeira National Park (PARNA), previously called Pico do Jabre State Park, in the State of Paraíba, Northeast Brazil. The checklist was prepared through field trips between 2018 and 2020 and compiled from a list of species published in 2004. The study compiled 335 species distributed in 70 families and 220 genera, while Fabaceae, Malvaceae and Asteraceae were the most representative families. Species richness depending on altitude was initially observed to be increasing, however, upon reaching intermediate levels of the altitudinal gradient, a decline in richness was observed, which continued to decrease until the top of the massif. Of the total number of documented species, there are representatives widely distributed in the Brazilian territory (141 spp.) as well as species also associated with the phytogeographical domains of Caatinga (281 spp.), Cerrado (254 spp.), Atlantic Forest (263 spp.), Amazon (157 spp.), Pampa (76 spp.) and Pantanal (82 spp.). The results demonstrate that the PARNA of Serra do Teixeira constitutes an important refuge for plant biodiversity, especially in the semi-arid region of Paraíba and Brazil.

Multi-scale temporal and spatial variations of soil heat flux under varying riparian forests: From a day to a year.

This study delves into the multi-scale temporal and spatial variations of soil heat flux (G) within riparian zones and its correlation with net radiation (Rn) across six riparian woodlands in Shanghai, each characterized by distinct vegetation types. The objective is to assess the complex interrelations between G and Rn, and how these relationships are influenced by varying vegetation and seasons. Over the course of a year, data on G and Rn is collected to investigate their dynamics. The multi-scale temporal patterns of G and its relationship with Rn are significantly influenced by both vegetation type and season, with the most pronounced variability observed seasonally, exhibiting distinct cycles for both broadleaf and conifer forests. The presence of shrubs is found to increase G, and the dominant temporal scales were found to vary within broadleaf forests. Additionally, G demonstrates a non-linear gradient with respect to the proximity to the river, with the river's influence on G diminishing at distances less than 11m in broadleaf and 6m in conifer woodlands. While the river enhances G and its hysteresis with Rn, vegetation characteristics dominate in dense canopies. This study underscores the importance of understanding the spatio-temporal variation patterns of soil heat flux and their response to different vegetation attributes. Such knowledge is vital for developing riparian soil heat flux models and informing riparian forest management strategies, especially in the context of climate change. The results provide insights into the complex interactions between soil heat flux, net radiation, and vegetation, offering a foundation for future research and management practices aimed at preserving and enhancing the ecological functions of riparian ecosystems.

Fire frequency shapes diversity in multi‐guild communities through direct and indirect pathways

Abstract Human‐induced changes in fire regimes worldwide are leading to changes in the diversity and composition of plant and insect communities through alterations in vegetation and habitat characteristics. As species interact in complex networks, environmental disturbances, such as an increase in fire frequency, can affect species directly and indirectly through cascading effects across trophic levels. This study examines the effects of fire frequency on multi‐guild communities in the Chaco region in Argentina, aiming to disentangle the direct and indirect pathways of influence between five different species groups: plants, phytophagous insects, ants, predators, and parasitoids. We assess cross‐taxon congruence by analysing α and β diversity indices and performing a structural equation model and Procrustes tests, respectively, trying to elucidate the pathways of influence between fire frequency and the different guilds. Multi‐guild communities responded to environmental changes produced by fire frequency via direct and indirect effects. Fire has both negative and positive, but weak indirect effects on predator richness through a bottom‐up cascading effect from plant richness across phytophagous insects and ants. However, when species relative abundances were considered, no effects have been observed on Shannon and Simpson diversity indices. A positive correlation between species composition of different guilds and fire frequency indicated congruence between connected guilds suggesting that changes in beta diversity propagate across all trophic chains. Given an increase in fire frequency, changes posed to vegetation translated in weak changes via species richness but through pronounced effects on species composition across different trophic levels. Our findings emphasise the importance of a multi‐guild approach to understanding biodiversity responses to environmental changes, highlighting the complexity and intricate dynamics of ecological communities in fire‐prone ecosystems.

Substitution of Chemical Fertilization using PGRs Evident in Growth and Yield of Tomato

The excessive utilization of synthetic fertilizers and chemicals poses a significant threat to both environment and human well-being. A pot experiment was done between December 2022 and April 2023 using a factorial randomized complete block design, which involved combining fertilizers and plant growth regulators (PGRs). The objective was to decrease the utilization of artificial fertilizers through the application of PGRs. The experiment involved applying fertilizers at 80, 90, 100 and 110% of the recommended doses. The recommended doses consist of 12 grams (g) of urea, 10 g of TSP, 5 g of MoP, 3 g of gypsum, 0.5 g of zinc sulphate, and 0.5 g of boric acid per plant. Furthermore, PGRs including gibberellic acid (GA3), naphthalene acetic acid (NAA), 4-chlorophenoxy acetic acid (4-CPA), and salicylic acid (SA) were applied at a concentration of 50 ppm. The results showed that there were no significant differences in growth and yield-contributing features when the fertilizer dose was increased from 80% to 110% of the recommended amount. Nonetheless, there were significant differences compared to the control group. However, PGRs showed significant variability in the morphological and reproductive responses of tomatoes under the conditions being researched. The GA3 treatment resulted in significantly greater plant height, base diameter, number of branches and leaves per plant, canopy spread, and internode length. Moreover, GA3 at 50 ppm produced the highest number of flowers and fruits/plant, with a single fruit weighing 67.83 g and a total fruit production of 6.61 kg/plant of tomato. Among the other PGRs, salicylic acid showed statistical equivalence to GA3 treatment. Nonetheless, there was a notable decrease in both vegetative and reproductive features, including yield, when NAA and 4-CPA were used. The interaction between fertilizers and PGRs showed that combining GA3 and SA with any of the tested fertilizer rates resulted in statistically distinct and improved vegetative and reproductive responses. However, the combination of fertilizer with NAA and 4-CPA produced highly unsatisfactory outcomes. Therefore, GA3 at 50 ppm and SA at 50 ppm can effectively be employed as substitute of synthetic chemical fertilizers in tomato cultivation. J. of Sci. and Tech. Res. 6(1): 53-64, 2024

Regional scale diversity and distribution of soil inhabiting Tetracladium

The genus Tetracladium has historically been regarded as an aquatic hyphomycete. However, sequencing of terrestrial ecosystems has shown that Tetracladium species might also be terrestrial soil and plant-inhabiting fungi. The diversity of Tetracladium species, their distribution across ecosystems, and the factors that shape community composition remain largely unknown. Using internal transcribed spacer (ITS) amplicon sequencing, we investigated the spatial distribution of Tetracladium in 970 soil samples representing the major ecosystems found across the British landscape. Species of the genus were found in 57% of the samples and across all vegetation types. The Tetracladium sequences we recovered included species common in aquatic ecosystems. However, we found five additional clades that clustered with environmental sequences previously found in terrestrial environments. The community composition of the Tetracladium OTUs was mainly related to vegetation type and soil pH. Strikingly, both taxon richness and overall abundance were highest in arable soils and showed positive relationships with soil pH. T. maxilliforme and a taxon of environmental sequences, Tetracladium group 1, was the biggest group, had the most relative abundance across ecosystems and was found in all vegetation types. Overall, this study provides insights into the community composition patterns of Tetracladium in terrestrial ecosystems and highlights the importance of vegetation characteristics in shaping Tetracladium communities.

Vegetation Effects on Air Pollution: A Comprehensive Assessment for Two Italian Cities

The role of urban vegetation in urban air quality is usually assessed by considering only the pollutant removal capacity of the plants. This study aims to show, for the first time, the effects of vegetation on air pollutant concentrations through its effects on meteorology, separately from its biogenic emissions. It also investigates how air quality changes when only biogenic emissions are altered by using plants with different emission factors, as well as the potential effects of introducing new vegetation into urban areas. These assessments were conducted using atmospheric modelling systems currently employed for air quality forecasting and planning, configured specifically for the cities of Bologna and Milan. Simulations were performed for two representative months, July and January, to capture summer and winter conditions, respectively. The variability in air concentrations of ozone (O3), nitrogen dioxide (NO2), and particulate matter (PM10) within the municipal boundaries was assessed monthly. When evaluating the impact of future vegetation, changes in temperature, wind speed, and relative humidity were also considered. The results indicate that vegetation influences air quality more significantly through changes in meteorological conditions than through biogenic emissions. Changes in biogenic emissions result in similar behaviours in O3 and PM10 concentrations, with the latter being affected by the changes in the concentrations of secondary biogenic aerosols formed in the atmosphere. Changes in NO2 concentrations are controlled by the changes in O3 concentrations, increasing where O3 concentrations decrease, and vice versa, as expected in highly polluted areas. Meteorologically induced vegetation effects also play a predominant role in depositions, accounting for most of the changes; however, the concentrations remain high despite increased deposition rates. Therefore, understanding only the removal characteristics of vegetation is insufficient to quantify its effects on urban air pollution.

Anthropogenic Drivers of Small-Island Effects in Urban Remnant Woody Plants.

The positive relationship between species richness and area is a fundamental principle in ecology. However, this pattern deviates on small islands, where species richness either changes independently of area or increases at a slower rate-a phenomenon known as the Small-Island Effect (SIE). While the SIE has been well documented in natural ecosystem, its presence in highly fragmented and disturbed urban ecosystem remains unexplored, posing challenges for urban vegetation conservation. Urban remnant vegetation, isolated by surrounding infrastructures, preserves intact zonal vegetation characteristics, serves as a benchmark for restoring near-natural habitats and offers ideal conditions to test the existence of the SIE in urban area landscapes. In this study, we surveyed 17 remnant vegetation patches in Qingdao City, China. A total of 331 plants attributed to 255 genera in 81 families have been recorded. Firstly, by using six species-area relationship regression models testing the SIE for remnant vegetation with different plant life forms, we found the SIE in only woody plants, with the land surface area threshold ranging from 6.38 ha (tree) to 11.91 ha (shrub). Our finding revealed that the drivers of the SIE in shrubs were landscape shape index, perimeter-area ratio, and the proportion of sealed surfaces within the patch. For trees, the SIE was influenced by the distance to the source of species, GDP, night light intensity, and perimeter-area ratio. This finding justifies that conservation in urban planning, construction, and development should focus not only on protecting large areas but also on maintaining and promoting diverse habitats within these areas. At the same time, reducing anthropogenic disturbance and enhancing the connectivity of green spaces are important for the persistence of metacommunities and can contribute to the local species pool, thus potentially improving the ecological resilience of urban environments.

Study on the Stability of Loess Landslides Based on Vegetation Characteristics and the Geo-Studio Model

Study on the Stability of Loess Landslides Based on Vegetation Characteristics and the Geo-Studio Model

Shrub height estimation for habitat conservation in NW Iberian Peninsula (Spain) using UAV LiDAR point clouds

ABSTRACT This study aimed to develop and validate a method of estimating 3D parameters from DJI Zenmuse L1 LiDAR on DJI Matrice 300 RTK UAV data to characterise and monitor the structure and conservation status of dense shrub formations. The shrub heights were estimated using Progressive Morphological Filter (PMF) and the Ground Filter module of the FUSION/LDV software. A digital terrain model (DTM) was interpolated with RMSE 0.23 and 0.27 m, respectively, and a normalised canopy height model (nCHM) was calculated by subtracting it from the LiDAR data and the best DTM obtained. The reliability of the estimates was evaluated against georeferenced field data. In addition, the study examined the impact of vegetation characteristics and return reduction in the original point cloud on the accuracy of LiDAR-data derived . Significant differences were found in the correlations between observed and estimated data for the DTM (R2 = 0.9998) and nCHM heights (R2 = 0.51/0.54). The corresponding RMSE values were 0.23 and 0.34 m. Moreover, no significant differences in the reliability were found for different vegetation types, whereas reduction point cloud density (up to 25–50 returns/m2) did not significantly affect accuracy. In conclusion, lightweight UAV LiDAR can effectively detect sub-metric scale vegetation 3D structure, useful for fine-scale habitat conservation.

Influence of Floral Strip Width on Spider and Carabid Beetle Communities in Maize Fields.

The study explored the impact of floral strip width on the spider and carabid beetle communities in maize fields over two years. Three widths of floral strips (2 m, 4 m, and 6 m) were compared with maize-only control strips to evaluate species diversity and distribution. The results showed significant differences in both spider and carabid populations between floral and control strips, with 4 m and 6 m widths consistently harboring higher biodiversity. The results also showed distinct community clustering within floral strips in 2021, which became more cohesive by 2022. Further analysis validated significant community dissimilarities between different strip widths and controls, highlighting the ecological advantages of wider floral strips for enhancing natural enemy biodiversity. Spider activity density was notably higher in floral strips than in adjacent farmland, peaking at the edges of 4 m-wide strips and decreasing in 6 m-wide strips, with the lowest density in 2 m-wide strips. Carabid beetle activity density varied considerably with strip width and proximity to the edge, typically peaking at the edges of wider strips. Spiders were more responsive to strip width than carabid beetles. Based on these findings, we suggest using 4 m- or 6 m-wide floral strips to enhance biodiversity and natural pest control in agricultural landscapes; the floral strips narrower than 4 m (such as 2 m) could not support optimal biodiversity, as spiders and carabid beetles do not disperse far into the maize field, with spiders having dispersal distances of less than 3 m and carabid beetles less than 10 m. Vegetation characteristics significantly influenced spider and carabid communities, impacting species richness, diversity indices, and community structures across two study years. These insights highlight the necessity of thoughtfully designing floral strips to enhance biodiversity and natural pest control in agricultural landscapes.