Plant Community Characteristics Research Articles

Plant species richness and phylogenetic diversity can favor the recovery of dung beetle communities in ecological restoration plots

Plant communities with higher species richness and phylogenetic diversity can increase the diversity of herbivores and their enemies through trophic interactions. However, whether these two features of plant communities have the same positive influence on other guilds through non-trophic mechanisms requires further exploration. Dung beetles represent an ideal system for testing such impacts, as they do not have a specialized trophic interaction with plants and are sensitive to changes in vegetation structure and the associated microclimate. We used a dataset of dung beetles collected from forest sites, restoration plots, and cattle pastures to (a) determine whether the richness and phylogenetic diversity of plants within restoration plots influence the total biomass and the taxonomic, functional, and phylogenetic diversity of dung beetles; and (b) determine if the establishment of restoration plots allows to recover the abundance and diversity of dung beetle communities, relative to what is found in livestock pastures. In the restoration plots, the abundance of Scarabaeinae beetles and the total biomass, functional originality, and phylogenetic diversity of dung beetles were positively related to the number of plant species, but only the abundance of Scarabaeinae and total biomass of all dung beetles were positively related to the plant phylogenetic diversity. Finally, the restoration plots allowed a threefold increase in the total biomass of dung beetles relative to the biomass found in pastures. We discuss how restoration plots with high plant species richness and phylogenetic diversity can favor the recovery of dung beetle communities by potentially creating more niche opportunities.

Diversity in Burned Pinyon–Juniper Woodlands Across Fire and Soil Parent Material Gradients

Co-varying disturbance and environmental gradients can shape vegetation dynamics and increase the diversity of plant communities and their features. Pinyon–juniper woodlands are widespread in semi-arid climates of western North America, encompassing extensive environmental gradients, and a knowledge gap is how the diversity in features of these communities changes across co-varying gradients in fire history and soil. In pinyon–juniper communities spanning soil parent materials (basalt, limestone) and recent fire histories (0–4 prescribed fires or managed wildfires and 5–43 years since fire) in Grand Canyon-Parashant National Monument (Arizona, USA), we examined variation at 25 sites in three categories of plant community features including fuels, tree structure, and understory vegetation. Based on ordinations, canonical correlation analysis, and permutation tests, plant community features varied primarily with the number of fires, soil coarseness and chemistry, and additionally with tree structure for understory vegetation. Fire and soil variables accounted for 33% of the variance in fuels and tree structure, and together with tree structure, 56% of the variance in understories. The cover of the non-native annual Bromus tectorum was higher where fires had occurred more recently. In turn, B. tectorum was positively associated with the percentage of dead trees and negatively associated with native forb species richness. Based on a dendroecological analysis of 127 Pinus monophylla and Juniperus osteosperma trees, only 18% of trees presently around our study sites originated before the 1870s (Euro-American settlement) and <2% originated before the 1820s. Increasing contemporary fire activity facilitated by the National Park Service since the 1980s corresponded with increasing tree mortality and open-structured stands, apparently more closely resembling pre-settlement conditions. Using physical geography, such as soil parent material, as a landscape template shows promise for (i) incorporating diversity in long-term community change serving as a baseline for vegetation management, (ii) customizing applying treatments to unique conditions on different soil types, and (iii) benchmarking monitoring metrics of vegetation management effectiveness to levels scaled to biophysical variation across the landscape.

Response of Plant Community Characteristics and Soil Factors to Topographic Variations in Alpine Grasslands.

Topography has an important influence on plant-soil relationships. However, research on plant-soil relationships in alpine grassland at the slope aspect and slope position scales is currently inadequate. In this paper, based on the topographic and geomorphological characteristics of the study area, alpine grassland with typical slope aspect and slope position conditions was selected as the research object. Through field investigations and laboratory research to reveal how the characteristics of the alpine grassland plant community and soil factors respond to changes in topography. The results show: Slope aspect and slope position changes significantly affect alpine grassland plant communities and soil properties. In terms of the dominant species in plant communities, the sunny slopes were dominated by Poaceae and the shady slopes were dominated by Polygonaceae. Plant community characterization variables showed a decreasing trend from shady to sunny slopes and bottom to top. The soil factors showed significant differences among the six types of topography (p < 0.05), and the magnitude order in different slope aspects and positions was basically shady slope > sunny slope and bottom > middle and top. Correlation analysis showed that there were good correlations between soil organic carbon (SOC), soil water content (SWC), total nitrogen (TN), pH, and plant community characteristics in alpine grassland. In addition, redundancy analyses (RDA) indicated that the divergence in plant community characteristics was primarily driven by the change difference in SOC along topographic gradients. Our findings may provide a scientific basis for the restoration and utilization of alpine grassland vegetation and the evaluation of the ecological environment in this region.

Light affects the resistance of native plant communities to Solidago canadensis with low invasion degrees

Light is an important factor for plant growth, and native plant communities are frequently invaded by alien plants to varying degrees. However, little is known about the effect of lighting on the resistance of native plant communities to alien plants with different degrees of invasion. We assessed the interactive effects of light condition and invasion degree on the growth of the invasive plant Solidago canadensis, the characteristics of the native plant communities and the invasion success of S. canadensis through both a field survey and greenhouse experiment. The field survey data showed that shading decreased the biomass of both S. canadensis and the native plant communities. However, it improved the relative dominance and thus, the invasion success of S. canadensis under the low and moderate invasion degrees but not at the high invasion degree. The data of the greenhouse experiment also showed that the native plant communities under shade were more susceptible to invasion by S. canadensis than the unshaded communities, particularly under the low and moderate invasion degree. In summary, we found that shading can weaken the resistance of native plant communities to alien plant invasions when there is a minimal invasion degree. These results underscore that managers need to be more attentive to the invasion of S. canadensis in sheltered environments. These findings provide a scientific reference to manage and control invasion by S. canadensis.

Exploring the potential mechanisms of Urban greenspaces providing pollution Retention and cooling benefits based on three-dimensional structure of plant communities

Establishing urban greenspaces is an effective approach for improving urban air quality and thermal environments. However, at a finer scale, the potential mechanisms of urban greenspaces providing pollution retention and cooling benefits remain unclear, especially for the three-dimensional structural characteristics of plant communities. To explore the potential mechanisms, we conducted field experiments on 108 plant communities in Beijing and simultaneously monitored PM10 concentration data and meteorological data both within and outside the plant communities. We analyzed the relationships between three-dimensional structural characteristic factors, the pollution retention benefit, and the cooling benefit. The results indicated that the majority of the plant communities (90.91%) can simultaneously provide both benefits. The herbaceous layer was a crucial factor influencing the pollution retention benefit, with a nonlinear positive correlation between the pollution retention benefit and the ratio of three-dimensional green biomass of herbs and trees (RTDGB-HT) and a threshold of 0.80-1.00. The tree layer was a crucial factor influencing the cooling benefit, as indicated by a positive linear correlation between the cooling benefit and the ratio of three-dimensional green biomass of trees (RTDGB-T). With changes in three-dimensional structural characteristic factors, the rate of change in pollution retention benefit factors was 3-5.5 times that in cooling benefit factors. Mediation analysis confirmed the trade-off between the pollution retention and cooling benefits, with trees indirectly enhancing pollution retention benefit by reducing the daily mean temperature reduction rate (R-Tmean) by 20.44-22.27% and by reducing the daily maximum temperature reduction rate (R-Tmax) by 13.14-15.99%. Overall, 13–23% of the pollution retention benefit was achieved through reducing cooling benefit, and interventions involving extreme heat can minimize the trade-off between the pollution retention and cooling benefits compared to reducing cooling benefit throughout the day. Our findings enrich and extend the current understanding of the correlations associated with the comprehensive benefits at the plant community scale, emphasizing the differences in three-dimensional structural characteristics that provide different benefits, which can better inform the development of refined and scientifically managed strategies for green space renovation.

Soil properties, climate, and topography jointly determine plant community characteristics in marsh wetlands.

Various environmental conditions influence the characteristics of plant communities within wetlands. Although the influence of key environmental factors on plant community traits within specific types of wetland ecosystems has been studied extensively, how they regulate plant communities across marsh wetland types remains poorly understood. We examined how environmental conditions influence plant communities in marsh wetlands along the lower Tumen River in northeastern China. We collected and analyzed data on the plant community characteristics (species, height, and coverage), soil physicochemical properties (organic carbon, inorganic nitrogen, and sulfur), and climatic and topographic factors (temperature, precipitation, and elevation) of 56 distinct marsh plots (29 herbaceous, 14 shrub, and 13 forested marshes) to understand how these variables correlate with plant community characteristics across marsh types. The wetland plant diversity varied, with the lowest, intermediate, and highest diversity occurring in herbaceous, shrub, and forested marshes, respectively. Climate, topography, and soil properties had crucial influences on plant diversity and biomass. Structural equation modeling showed that, in herbaceous marshes, plant biomass was primarily determined by soil and plant diversity, with climate exerting an indirect effect. In shrub marshes, soil, climate, and plant diversity directly influenced biomass. In forest marshes, soil and plant diversity directly affected biomass, whereas climate and topography had indirect effects. These findings highlight the complex interactions among environmental factors across marsh ecosystems and their influence mechanisms on biomass, aiding in formulating effective conservation and restoration strategies for marsh wetland ecosystems.

Methodological Issues in Pollen Analysis of Pleistocene Deposits in Denisova Cave

Denisova Cave, in the northwestern Altai, is a key Paleolithic complex in North Asia. Pleistocene deposits in the cave contain lithic industries and human fossils documenting the evolution of the cultural traditions of Denisovans in the second half of the Middle and in the Upper Pleistocene. This study addresses methodological issues in paleogeographic interpretation of pollen records relating to Quaternary deposits of cave sites. We present the results of the analysis of recent and subrecent spectra of cave sediments and soil samples taken at sites of characteristic plant communities in natural zones of the Anui River valley near Denisova Cave. Findin gs from taphonomic study of pollen microremains from loose sediments in the East Chamber of the cave make it possible to obtain a correct climato-stratigraphic and climato-phytocenotic interpretation of pollen spectra from Pleistocene deposits in Denisova Cave.

Quantitative classification and biodiversity characteristics of plant communities in Luoshan Mountain steppe, Ningxia, China

To understand the distribution pattern and influencing factors of plant community and diversity along the altitude gradient, we examined plant community types, plant diversity and phylogenetic diversity of mountain steppe in Luoshan, Ningxia, and analyzed the relationship between the plant community and its diversity and environmental driving factors. The results showed that the main community types in the mountain steppe were Asterothamnus centraliasiaticus community, Caragana tibetica community, Convolvulus tragacanthoides community, Stipa bungeana community, Stipa breviflora＋Ajania achilloides community, Artemisia frigida community, Roegneria alashanica＋S. breviflora＋Hedysarum polybotrys community, S. breviflora＋Stipa grandis community, S. grandis＋S. bungeana community, Cyperus glomeratus community, S. grandis community and Carex aridula community. The distribution of mountain steppe community was mainly affected by altitude, soil alkali-hydrolyzed nitrogen, water content, available potassium, silt and organic matter contents, with altitude and soil water content having the greatest effects (P<0.01). The Patrick index and phylogenetic diversity index (PD) of plant community showed an increasing trend with the altitude increase, the Shannon index and Pielou index showed a unimodal trend, and the phylogene-tic structure gradually changed from aggregation to dispersion. There was a significant positive correlation between species diversity index and PD index. Shannon index was negatively correlated with net relatedness index (NRI). Plant species diversity and phylogenetic diversity of mountain steppe were mainly affected by soil water content, available potassium, total nitrogen, silt and sand contents. NTI was significantly affected by altitude, while the NRI index was significantly affected by soil silt content.

Ecological conditions of growth and breeding analysis of Viburnum opulus L. populations in the Kazakhstan part of the Altai Mountains

Abstract. Danilova AN, Vdovina TA, Isakova EA, Kotukhov YA, Sumbembayev AA. 2024. Ecological conditions of growth and breeding analysis of Viburnum opulus L. populations in the Kazakhstan part of the Altai Mountains. Biodiversitas 25: 2845-2857. The purpose of this paper was to study the ecological growth conditions of Viburnum opulus populations and the variability of the main morphological parameters of the vegetative and generative spheres of the species at the interpopulation level in the Kazakhstan part of the Altai Mountains as a future promising donor for breeding work. As a result of field research, using route-reconnaissance, traditional geobotanical, and morphometric methods, 24 isolated locations of V. opulus were discovered in the Kazakhstan Altai in the geographical areas of Kalbinsky, Western, and Southern Altai. These areas' ecological conditions of the species growth were studied for the first time, based on which the characteristics of plant communities with the participation of V. opulus were compiled. It was found that the species grows mainly in three types of associations: tree-shrub, shrub-meadow in the forest zone, and steppe shrub-meadow in the mountain-steppe zone. Plant communities with the participation of V. opulus occupy areas on the northwestern and southeastern mountain slopes associated with river valleys. The vertical range of distribution of the species varies from 395 to 913 masl. The total area of the territory occupied by plant communities with the participation of V. opulus was 198.85 ha. Furthermore, when studying interpopulation variability in 9 populations isolated from each other and located in different ecological and geographical growing conditions, 3 main groups of characteristics were identified depending on the degree of variability. High variability was revealed in the height of the shrubs, fruits in the cluster and their weight, the color of ripe berries, taste indicators for fruit bitterness from 1 to 4 points, and yield. Promising populations regarding productivity were identified in Kalbinsky, Western, and Southern Altai, depending on the ecological and geographical growth in the Kazakhstan Altai.

Fine-scale monitoring of catkins reveals an association between catkin concentration and plant community characteristics and microclimate

Catkins, as a significant source of plant-caused pollution, disrupts daily human activities and industrial processes. Despite their impact, catkins have not been included in official environmental quality monitoring indicators, leading to a deficiency in scientifically rigorous collection and monitoring methodologies, as well as a lack of ecological prevention and management strategies. In this study, we introduced a fine-scale monitoring approach for catkins. Qualitative and quantitative relationships between catkin concentrations, plant community characteristics and microclimate factors were elucidated by analyzing on-site catkin concentration data from 33 representative plant communities in Beijing. Furthermore, we summarized the ecological strategies for the prevention and management of these catkins. The results indicated that (1) TS (three-dimensional green volume of trees in the catkin source layer), SB (three-dimensional green volume of shrubs in the catkin barrier layer), GB (three-dimensional green volume of ground cover plants in the catkin barrier layer), T (three-dimensional green volume of trees in the whole plant community), W (three-dimensional green volume of the whole plant community), species diversity, and relative air humidity were key plant community characteristics and microclimate factors influencing catkin concentration. Among these factors, TS, T, W, and relative air humidity showed a significant positive correlation with catkin concentration, while SB, GB, and species diversity exhibited a significant negative correlation with catkin concentration. (2) All seven key factors exhibited nonlinear relationships with catkin concentration. (3) TS served as the primary deciding factor for catkin concentration within the plant community. When TS > 744.0755 m3, the secondary decision factor for catkin concentration was GB. Otherwise, the determinants were SB and species diversity. The results showed that enhancing tree species diversity, enhancing the three-dimensional green volume of shrubs and ground cover plants, and increasing air humidity were practical means to facilitate the sedimentation of catkins. The measures used to obstruct catkins vary depending on the TS. When catkin source plants are abundant within a plant community, it is advisable to prioritize increasing ground cover plants. Conversely, when fewer sources of such plants exist, emphasis can be placed on augmenting mid-layer shrubs and diversifying plant species. These findings provide a scientific foundation for the planting design and stock optimization of communities containing catkin source plants.

Spatial Distribution Characteristics of Plant Community and the Identification of Driving Factors in Riparian Zone of the Three-River Headwaters Region, China

The unique geographical and climatic conditions in the Three-River Headwaters Region gave birth to distinctive plant species and vegetation types. To reveal the spatial distribution of plant communities and soil habitats along the riparian zone of the Sanjiangyuan Region and their influencing mechanisms, 14 survey plots were set up （ten from the Yangtze River source, two from the Lancang River source, and two from the Yellow River source）, and the effects of soil nutrient characteristics （especially soil phosphorus morphology）, climate factors, and river topography on plant community characteristics were quantitatively analyzed. The results showed that the plant community composition in the riparian zone of the source of the three rivers was dominated by perennial herbs （72.2%）, followed by annual herbs （20.4%） and shrubs （7.4%）. The dominant plants were Stipa purpurea, Polygonum orbiculatum, Carex parvula, Potentilla anserina, and Gentiana straminea. The average plant coverage, Shannon-Wiener index, and Pielou index were （64.4% ±23.6%）, （1.31 ±0.42）, and （0.84 ±0.08）, respectively. The plant community diversity index was the highest in the Yangtze River source, followed by that in the Lancang River source, and the lowest in the Yellow River source. The soil pH of the riparian zone of the Yangtze River source was significantly higher than that of the Lancang River source, whereas the mean contents of organic matter, total nitrogen, and Fe-Al combined phosphorus were significantly lower than those of the Lancang River source. The calcium and magnesium-combined phosphorus was the main form of phosphorus in riparian soil （63.89%）. Temperature, soil organic phosphorus content, and pH had significant effects on plant composition in the riparian zone of the Three-River Headwaters Region, whereas soil calcium and magnesium-combined phosphorus content had significant effects on plant community diversities. These results may deepen the scientific understanding of the evolution trend and genetic mechanism of plant communities in the riparian zone of the Three-River Headwaters Region.

Landscape changes of alpine grasslands in the Zhari Namco basin of the central‐southern Qiangtang plateau, 2001–2021

AbstractThe alpine grasslands of the Qiangtang Plateau face significant ecological risks due to extensive human activities, particularly in areas along lakeshores and riverbanks, where overgrazing has caused severe degradation and salinization of the grasslands. Conducting fieldwork in such environments presents significant challenges for long‐term community‐scale landscape ecological research. In this study, the habitat characteristics of dominant plant communities in the alpine basin of Zhari Namco were quantified from three perspectives: topography, hydrology, and fractional vegetation cover. Using Aster GDEM and Landsat imagery, five grassland types were mapped for 2001–2021. Based on the spatial variables of area, shape, and distance, 13 landscape indices were selected to observe spatiotemporal changes. The results revealed several key findings: (1) The patch structure of the zonal vegetation Stipa purpurea steppe has undergone a pattern of dispersion‐aggregation‐dispersion in the past 20 years, yet the core habitat area remains unchanged by more than 52%, indicating fundamental stability in the southern Qiangtang alpine grassland; (2) Using the minimally grazed Kobresia pygmaea meadow as a reference, other communities exhibit stability similar to or approaching it, but with significant differences in aggregation level. The gradual expansion of grazing and economic activities has been a driving factor; and (3) Water conservation projects have diversified the use of water resources in river and lakeside habitats. Stipa purpurea + Carex moorcroftii steppe and Carex swamp meadow exhibit optimal carrying capacity, making them the only areas with relatively high sustainability. The study underscores that the current ecological benefits are a result of effective management. However, without proper management, the region could trend towards landscape fragmentation, becoming the most vulnerable zone in the watershed. Therefore, it is essential to strengthen retrospective analysis of grazing intensity and trend analysis of habitat changes to provide a scientific basis for local economic development and grazing management.

Precipitation-induced soil properties and plant communities mediate root strategies in an alpine meadow

Abstract Plant roots show flexible traits to changing precipitation, but the factors driving root trait covariation remain poorly understood. This study investigated six key root traits, and the potential driving factors, such as the plant community characteristics and soil properties in the Zoige alpine meadow across five precipitation gradients, including the natural precipitation (1.0P), 50% increasing precipitation (1.5P), 30%, 50% and 90% decreasing precipitation (0.7P, 0.5P and 0.1P, respectively). Our results demonstrated distinct root trait responses to changes in precipitation. Both increasing (1.5P) and decreasing precipitation (0.1P, 0.5P, and 0.7P) inhibited root diameter (RD), specific root length (SRL), and specific root area (SRA) compared to 1.0P. Conversely, root tissue density (RTD) and root nitrogen content (RNC) increased under decreasing precipitation but declined under 1.5P. With increasing precipitation, root foraging strategies shifted with thinner RD and larger SRL to that with larger diameter. Shifts in root strategies were primarily influenced by soil properties, specifically soil water content and available nitrogen. Additionally, root strategies in surface soils (0–10 cm) were mainly related to the grass and sedge coverage, whereas in deeper soils (10–20 cm) root strategies were related to overall plant community coverage and biomass. Our findings indicate that root traits variations and strategies in alpine meadows are co-driven by soil properties and plant communities in response to changing precipitation

Topography and soil variables drive the plant community distribution pattern and species richness in the Arjo-Diga forest in western Ethiopia.

Understanding plant community characteristics, distributions, and environmental relationships is crucial for sustainable forest management. Thus, this study examined the relationships between plant community composition and topographic and soil variables within the Arjo-Diga forest. Vegetation data were collected from 72 nested plots (30 × 30 m2 and 2 × 2 m2) systematically laid along nine transects spaced 300 to 700 m apart. Environmental variables, including soil properties and anthropogenic disturbance, were recorded within each main plot. Agglomerative hierarchical cluster analysis and canonical correspondence analysis (CCA) using R software were employed to identify distinct plant community types and examine their relationships with environmental factors. The Shannon‒Wiener diversity index was calculated to quantify and compare species diversity among the identified community types. The analysis revealed five distinct plant community types: 1: Maesa lanceolata-Ehretia cymosa, 2: Trichilia dregeana-Flacourtia indica, 3: Acacia abyssinica-Millettia ferruginea, 4: Combretum collinum-Croton macrostachyus, and 5: Terminalia macroptera-Piliostigma thonningii. The CCA results highlighted the significant influence (p < 0.05) of altitude, CEC, TN, and disturbance on species distribution and plant community formation. The findings indicate that variation in plant communities is closely associated with altitude, TN, and CEC, as well as with disturbance factors such as human interventions, with elevation being the most influential factor. Based on these findings, it is recommended that conservation plans consider the effects of human interventions to address the challenges in conserving forests in the future. Additionally, further research efforts should focus on mitigating disturbance factors and understanding the environmental variables that affect forests to improve their protection.

Factors governing the dynamics of soil organic carbon and nitrogen in wetlands undergoing management changes in a semi-arid region

Soil organic carbon and nitrogen play pivotal roles as indicators of soil quality and ecological functioning in wetlands. The escalating impact of human activities and climate change has led to a severe degradation of wetland soils, particularly in semi-arid regions. However, an understanding of the factors governing the dynamics of total soil organic carbon (TSOC) and total soil nitrogen (TSN) in semi-arid areas remains elusive, impeding a comprehensive understanding of wetland ecological functions. The present study investigated variations in TSOC and TSN content as well as vegetation and soil physicochemical properties under five different land management practices (mowed wetlands, mowed and slightly grazed wetlands, moderately grazed wetlands, heavily grazed wetlands, and natural wetlands unaffected by human interference) in the semi-arid Songnen Plain region of China. The results revealed significant decreases in TSOC and TSN content within managed wetlands compared to natural wetlands. Moreover, positive correlations were observed between pairs of SOC-TN or their storage values for SOC (TSOC)-TN (TSN). Furthermore, TSOC and TSN exhibited significant positive associations with aboveground and belowground biomass levels, stem C:N, stem C:P, soil C:P, and soil N:P. Additionally, redundancy analysis indicated that species diversity accounted for 37.4% of the variations in TSOC-TSN while belowground biomass accounted for 8.5% of the variations. Furthermore, nutrient content within stems (particularly N content and C:P) contributed to a 37.2% variation in TSOC and TSN whereas root nutrient content (especially N:P, C:N, and C:P) contributed to a 15.3% variation. Soil C:P, C:N, and total phosphorous (TP) content accounted for 65.7%, 9.6%, and 7.5% of variations of TSOC and TSN, respectively. Besides, variation partitioning analysis revealed that plant community characteristics, community nutrient content, and soil physicochemical properties collectively influenced the dynamics of TSOC and TSN. Among these factors, soil physicochemical properties emerged as the primary drivers of carbon and nitrogen dynamics in degraded wetlands in semi-arid regions. The impact on TSN was more pronounced than that of TSOC. This study provides valuable insights for understanding the processes and mechanisms underlying carbon and nitrogen accumulation in degraded wetlands, facilitating the development of regionally adaptive management plans under different management practices.

Effects of Land Use Change on Soil Aggregate Stability and Erodibility in the Karst Region of Southwest China

Differences in land use type and chronological age affect soil properties and plant community characteristics, which may influence soil structural stability and erodibility. However, knowledge on the effects of soil physicochemical properties on soil aggregate stability and erodibility at different land use years is limited. This study selected five land use types: corn field (Year 38th-y), corn intercropped with cabbage field (Year 38th-y + b), fruit and meridian forest (Year 6th-jgl), naturally restored vegetation (Year 6th-zr), and artificial forest (Year 7th-rgl) in the karst landscape of the Chishui River Basin in Yunnan Province. We aimed to identify the influencing factors of soil stability and erodibility under different land use time series. The results indicated that the mean weight diameter (MWD), the geometric mean diameter (GMD), and soil structural stability index (SSI values) were highest in Y6th-zr and lowest in Y7th-rgl. Conversely, the erodibility K value was lowest in Y6th-zr, suggesting that the soil structure in Y6th-zr exhibited greater stability, whereas soil stability in Y7th-rgl was lower. Redundancy and throughput analyses revealed that organic carbon and water-stable aggregates &gt; 2.0 mm content had higher vector values. Soil bulk density, total nitrogen, organic carbon, and soil texture content were the main factors contributing to soil stability variation (0.338–0.646). Additionally, total nitrogen, organic carbon, total phosphorus, and soil texture content drove the variation in K values (0.15–1.311). Natural vegetation restoration measures can enhance soil structure to a certain extent. These findings highlight changes in soil aggregate stability and erodibility over different land use durations. The research results have important theoretical and practical significance for understanding the differences in soil erosion and soil restoration under different land use patterns in the karst landscapes of southwest China.

Assessing the effects of urban green spaces metrics and spatial structure on LST and carbon sinks in Harbin, a cold region city in China

In the face of accelerated urbanization, urban green spaces (UGSs) are crucial in alleviating urban heat island effects. This study investigates the link between UGS landscape patterns, plant community characteristics, Land surface temperature (LST), and Annual carbon sequestration of plant community (ACSPC) across different seasons and scales in Harbin by remote sensing and field measurements. The results show that (1) The LST in urban built-up areas shows an increasing trend, and its correlation with UGS exhibits seasonal fluctuations. (2) Landscape pattern metrics significantly relate to LST, particularly at 1500 and 1260 m window scales. (3) In summer and winter, Aggregation index (AI) , Mean patch area (AREA_MN), Edge density (ED), Percentage of landscape (PLAND), Mean patch shape index (SHAPE_MN), Mean diameter at breast height (MDBH), Mean canopy diameter (MCD), Average carbon sequestration capacity(ACSC), and Leaf area index (LAI) are positively correlated, whereas Sky view factor (SVF) is negatively correlated with ACSPC. (4) LAI, SVF and MCD (winter) significantly affect LST. MDBH, MCD, and SVF in summer significantly influence ACSPC. This research elucidates the effect of UGS landscape patterns and plant community characteristics on urban heat islands and carbon sinks, providing vital insights for urban ecological improvement.

Riparian plant-soil-microbial C:N:P stoichiometry: are they conserved at plant functional group level?

As a consequence of the tight linkages between plants, soil, and microorganisms, we hypothesized the variations in plant species would change soil and microbial stoichiometry. Here, we examined the plant leaf carbon (C):nitrogen (N):phosphorus (P) ratios of nine species coming from three plant functional groups (PFGs) in the riparian zones of Hulunbuir steppe during near-peak biomass. The soil C:N:P, microbial biomass carbon (MBC):microbial biomass nitrogen (MBN), and extracellular enzyme's C:N:P were also assessed using the soils from each species. We found that plant tissue, soil nutrient, microbial, and enzyme activity stoichiometry significantly differed among different PFGs. Plant leaf and soil nutrient ratios tended to be similar (p > 0.05) between different species within the same PFGs. The variations in leaf C:N:P significantly correlated with the changes in soil C:N:P and MBC:MBN ratios. The homeostatic coefficients (H) < 1 suggested the relationships between plants and their resources C:N:P ratios might be non-homeostatic in the examined riparian zone. By assessing plant tissue and its soil nutrient stoichiometry, this study provided a perspective to understand the linkages of plant community, soil nutrient, and microbial characteristics.

Relationships and Changes in Grassland Community Diversity and Biomass in the Pastoral Areas of the Two Rivers under Grazing Disturbance

Grazing affects plant community characteristics and the relationship between above-ground biomass and diversity, which has become a hot topic in grassland ecosystem research in recent years. The present study investigated grassland vegetation in the Two Rivers pastoral area based on 60 sampling points using sampling methods. The effects of grazing on the structural characteristics of plant communities were analysed using the α-diversity index, and the relationship between species diversity and the above-ground biomass of plant communities, as well as their changes, was explored. The results showed that grazing disturbance decreased the number of family species in the grassland plant communities and the similarity between communities; grazing activities significantly decreased the above-ground biomass of the grassland plant communities; the height and cover also showed a decreasing trend (p &lt; 0.01), but the density of the grassland plant communities improved (p &lt; 0.01). The Margalef index, the Shannon–Wiener index, and the Simpson index of the grassland plant communities all showed different degrees of decrease after grazing, while the Alatalo index showed an increase; biomass was positively correlated with the Margalef, Shannon–Wiener, and Alatalo indices and negatively correlated with the Simpson index (p &lt; 0.01). Therefore, in the management and maintenance of grasslands, the impact of grazing on the structural characteristics of plant communities should be taken into account, and reasonable response policies should be implemented according to the actual local situation. This study provides a theoretical basis for grassland maintenance and management and the sustainable development of ecosystems in the pastoral areas of the two river sources of the Altay Mountains.

Vegetation cover is a crucial key to the success of ecological restoration in the desertified steppe of Inner Mongolia

In this study, we analyzed the environmental factors influencing the restoration process of the degraded ecosystem in the Inner Mongolian steppe, the largest steppe ecosystem in Asia, which is experiencing rapid desertification, and evaluated the effects of restoration on the damaged ecosystem in China. For this purpose, we selected degraded steppe areas left to desertification in the Hulunbuir region, four restored sites where vegetation was artificially introduced for restoration, and reference ecosystems, including a non-desertified area with the dominant Pinus sylvestris var. mongolica community and a meadow steppe area. We conducted analyses and monitoring of plant community characteristics and soil environmental factors to assess the progress of restoration. The results showed that the introduction of indigenous woody plants in the degraded areas led to a proportional increase in vegetation cover, plant biodiversity, and species abundance over time. The primary external forces driving the succession of vegetation in the restored sites were soil factors including organic matter content, temperature and total nitrogen levels, which were associated with an increase in vegetation cover. These results can be interpreted as an increase in vegetation cover leading to an increase in litter production. This in turn reduces soil temperature and evaporation, subsequently enhancing the activity of soil microorganisms. Over time, the species composition, structural diversity of communities, and ecosystem functions in the restored sites gradually became more similar to those of the reference ecosystems. This indicates that vegetation restoration in this area has been very successful. In particular, the positive change in local residents’ awareness regarding the necessity of restoration has been considered a crucial contribution to the success of restoration in the degraded areas. It has led to a decrease in perceived anthropogenic threats to the restored sites. These results indicate that the introduction of native woody plants is crucial and can increase vegetation cover and species composition complexity and local residents’ positive perception of restoration for the successful restoration of desertified drylands.