Vegetation Communities Research Articles

The Effects of Legacy Sediment Removal and Floodplain Reconnection on Riparian Plant Communities

Stream restoration includes a number of different approaches intended to reduce sediment and nutrient export. Legacy sediment removal (LSR) and floodplain reconnection (FR) involve removing anthropogenically derived sediment accumulated in valley bottoms to reconnect incised streams to their floodplains. These projects also present an opportunity to create high-quality riparian and wetland plant communities and provide information about the early stages of wetland vegetation development and succession. We surveyed vegetation immediately after restoration at three sites and at three additional sites 1–3 years post-restoration to determine how LSR/FR affects riparian plant communities. Restoration increased the prevalence of hydrophytic herbaceous species at all sites, suggesting these projects successfully reconnected the stream to the floodplain. Pronounced decreases in woody basal area and stem density likely also influenced an increase in native and graminoid species after restoration. Only 16% of the indicator species identified for restored reaches were planted as part of the restoration, suggesting the local seed bank and other seed sources may be important for vegetation recovery and preservation of regional beta diversity. Although vegetation quality increased after restoration in reaches with initially low-quality herbaceous vegetation, vegetation quality did not improve or decreased after restoration in reaches with higher-quality vegetation before restoration. The practice of LSR/FR has the potential to improve the quality of some riparian vegetation communities, but the preservation of high-quality forested areas, even if they are atop legacy sediment terraces, should be considered, particularly if reductions in nutrient export do not offset losses in tree canopy.

Effective microorganisms input efficiently improves the vegetation and microbial community of degraded alpine grassland.

Soil beneficial microorganism deficiency in the degraded grasslands have emerged as the major factors negatively impacting soil quality and vegetation productivity. EM (effective microorganisms) has been regarded as a good ameliorant in improving microbial communities and restoring degraded soil of agricultural systems. However, knowledge was inadequate regarding the effects of adding EM on the degraded alpine grassland. Four levels of EM addition (0, 150, 200, 250 mL m-2) were conducted to investigate the effects of EM addition on soil properties and microorganisms of degraded alpine grassland. The addition of EM increased aboveground biomass, soil organic carbon, total nitrogen, available phosphorus, and microbial biomass, but decreased soil electric conductivity. Meanwhile, the relative biomasses of gram-negative bacteria decreased, while the ectomycorrhizal fungi and arbuscular mycorrhizal fungi increased after EM addition. The relationship between microbial communities and environmental factors has been changed. The restore effect of EM increased with the increase of addition time. These results indicated that EM addition could be a good practice to restore the health of the degraded alpine grassland ecosystem.

Nitrogen immobilization could link extreme winter warming events to Arctic browning

Arctic extreme winter warming events (WW events) have increased in frequency with climate change. WW events have been linked to damaged tundra vegetation (“Arctic browning”), but the mechanisms that link episodic winter thaw to plant damage in summer are not fully understood. We suggest that one mechanism is microbial N immobilization during the WW event, which leads to a smaller release of winter-mineralized N in spring and therefore more N limitation for vegetation in summer.We tested this hypothesis in a Western Greenlandic Low arctic tundra, where we experimentally simulated a 6 day field-scale extreme WW event and 1) used stable isotopes to trace the movement of N as a consequence of the WW event, 2) measured the effect of a WW event on spring N release in top soils in the laboratory, and 3) measured the carry-over effect on summer aboveground vegetation C/N ratio in tundra subject to a WW event.Our results show that soil mineral N released by a WW event followed by soil thaw is taken up by microbes and stored in the soil, whereas vascular plants acquired almost none, and significant amounts were lost to leaching and gaseous emissions. As soils thawed in spring, we saw weak but not significant evidence (P = 0.067) for a larger N release over the first month of spring thaw in Control soils compared to WW event soils, although not significantly. A weak signal (P = 0.07) linked WW event treatment to higher summer C/N ratios in evergreen shrubs, whereas deciduous shrubs were not affected.We conclude that our results did not show significant evidence for WW events causing Arctic browning via N immobilization and summer N limitation, but that we had indications (P < 0.1) which merits further testing of the theory in various tundra types and with repeated WW events. Evergreen shrubs could be especially sensitive to winter N immobilization, with implications for future vegetation community composition and tundra C storage.

Landscape regulation of microbial use of terrestrial carbon in boreal streams

Microbes decomposing leaf litter in aquatic ecosystems are exposed to two major sources of carbon (C), namely, particulate organic C (POC) and dissolved organic C (DOC). The use of DOC relative to POC during litter decomposition likely depends on the availability of DOC, which in turn is regulated by the characteristics of the surrounding landscape, although this extrinsic indirect control of DOC use remains largely unexplored. We have investigated how variations in stream physical and chemical characteristics, distribution of major landscape elements (i.e., forest, mires, and lakes), and riparian vegetation community composition (i.e., relative cover of deciduous vs. coniferous tree species) influence DOC use by leaf-associated microbes (LAM). Specifically, in a boreal stream network of ten first- to third-order streams, we related in-stream characteristics, landscape elements, and riparian vegetation community composition to DOC/POC respiration ratios (i.e., the amount of CO2 produced by LAM respiration of DOC + POC divided by the amount of leaf C mass lost through decomposition). The results showed that DOC/POC respiration ratios were > 1 in most of the study sites, indicating that LAM use a substantial amount of DOC during leaf litter decomposition. This microbial reliance on DOC varied with in-stream DOC and nutrient concentrations, proportional mire and forest cover, and riparian vegetation community composition. In particular, high mire and coniferous cover increased DOC use by LAM. As such, landscape configuration and how it is modified by land use and climate change must be considered in order to understand microbial turnover of terrestrial C in boreal streams.

Mapping native and non-native vegetation communities in a coastal wetland complex using multi-seasonal Sentinel-2 time series

Mapping native and non-native vegetation communities in a coastal wetland complex using multi-seasonal Sentinel-2 time series

Catchment-scale hydrology limits the benefits of geomorphic complexity for instream vegetation communities

Improving instream habitat complexity is a common stream restoration approach despite often limited improvements to stream biota with catchment-scale stressors such as altered hydrology thought to be more important. Instream vegetation is a critical component of lowland stream ecosystems, providing multiple ecological benefits. Thus, we asked: How does instream vegetation respond to (1) geomorphic complexity; (2) different flow regime components; and (3) what is the relationship between geomorphic complexity and flow in driving instream vegetation?We surveyed instream vegetation and geomorphology along 23 lowland stream reaches. We investigated associations between six measures of geomorphic complexity, six flow metrics, and amphibious and aquatic vegetation richness, Shannon diversity and cover.Amphibious vegetation was negatively associated with simplified channels and increasing flood frequency. Increasing depth and width variation, and Julian day low flow variability, were positively associated with aquatic vegetation. Considering sites with complex (stable) or simplified (unstable) geomorphology separately, only vegetation at stable sites showed strong relationships to flow regime components, with variables related to flow flashiness negatively associated with both amphibious and aquatic vegetation, and Julian day low flow variability positively associated with aquatic vegetation.We identified channel complexity, variables related to flow flashiness and variation in low flow timing, as key geomorphic and flow drivers of instream vegetation, respectively. Importantly, our results suggest that instream vegetation benefits from improving geomorphic complexity are likely to be limited without also addressing altered flow regimes.

A host-based approach for the prioritisation of surveillance of plant pests and pathogens in wild flora and natural habitats in the UK

AbstractNon-native plant pests/pathogens are a mostly overlooked threat to biodiversity. Surveillance for plant pests and pathogens is key to early detection yet is rarely undertaken in natural habitats. Current methodologies to prioritise surveillance are pest-based, there is no methodology available to help managers identify 'at risk' hosts and habitats for targeted surveillance. This study compares four host-based methods. Prioritisation of: (1) plant genera known to host the pests/pathogens most likely to establish (Host-pest); (2) habitats known to host the greatest number of pests/pathogens most likely to establish (Habitat-pest); (3) plants classed as foundation species (those that drive ecosystem functioning and support populations of dependent biodiversity) (Foundation-species); (4) habitats with low plant species diversity and hence low resilience (Habitat-resilience). Twelve habitats and 22 heathland vegetation communities in the UK were used as a case-study. The Host-pest method gave 121 plant genera to monitor across all habitats and 14 within heathlands. The Habitat-pest and Habitat-resilience methods prioritised different habitats because the Habitat-pest method uses existing lists of pests which are biased towards those of commercial importance. The Foundation-species method gave 272 species for surveillance across all habitats and 14 within heathlands. Surveillance of habitats and plants prioritised on potential ecological impact (the Foundation-species and Habitat-resilience methods) is recommended rather than known pests/pathogens (the Host-pest and Habitat-pest methods) as this avoids biases within existing lists of pests/pathogens, removes the need for the prioritisation to be regularly updated as new pests/pathogens are identified and takes account of impacts on associated biodiversity and ecosystem functions.

Spatio-temporal Variation in Net Primary Productivity of Different Vegetation Types and Its Influencing Factors Exploration in Southwest China

Studying the spatiotemporal variation in vegetation net primary productivity (NPP) and exploring its influencing factors are of considerable practical significance for understanding the spatiotemporal variation in vegetation and for guiding ecological restoration and management projects based on local conditions. Based on MODIS NPP data, combined with in situ meteorological data, land use data, and vegetation type data, this study explores the spatiotemporal variation in different types of vegetation NPP in southwest China via the Mann-Kendall significance test and Theil-Sen Median slope estimator. It reveals the influencing factors of spatial differentiation of different types of vegetation NPP and the interaction between influencing factors in combination with stability analysis and Geo Detectors. The results revealed that on the temporal scale, from 2000 to 2021, vegetation NPP, NPPPre (vegetation NPP exclusively under the influence of climate change), and NPPRes (vegetation NPP exclusively under the influence of human activities) in southwest China showed a fluctuating upward trend. Among different vegetation types, NPP, NPPPre, and NPPRes exhibited an upward trend, except for a minor decline in NPPRes of tree vegetation at a rate of -0.183 g·(m2·a)-1. Among them, NPP, NPPPre, and NPPRes of economic vegetation showed the most significant upward rates, 5.96, 3.09, and 2.94 g·(m2·a)-1, respectively. On the spatial scale, the tree vegetation NPP with the most significant downward trend was mainly distributed in Tibet and southern Yunnan, while the economic vegetation NPP with the highest upward trend was primarily distributed in eastern Sichuan Province. The stability of vegetation NPP in southwest China presented a spatial distribution pattern of "low in the south and high in the north," and the average value of the correlation coefficient increased in the ascending order of arbor vegetation (0.101), shrub vegetation (0.105), herb vegetation (0.110), and economic vegetation (0.114). The interaction between surface temperature and relative humidity was the main influencing factor for spatial differentiation of vegetation NPP, while the interaction between sunshine duration and warmth index had the most significant impact on vegetation in southwest China, with an increasing percentage of 30.91%. Different types of vegetation had different requirements for different climatic factors, but their requirements for surface temperature and warmth index were significantly consistent. When the surface temperature was 21.03-28.49℃, and the warmth index was 106.46-167.2, the NPP of different vegetation types peaked. Under natural succession, the impact of climate change on vegetation was inversely proportional to the stability of the vegetation community. The arbor vegetation community with high stability was less affected, while the herb vegetation community with low stability was highly affected by climate. In contrast, the stability of economic vegetation was directly proportional to the impact of climate due to the influence of human activities. This study establishes a theoretical foundation for evaluating the impact of regional climate on the growth of different vegetation types and can be crucial for formulating ecological restoration and management strategies in southwest China that are adapted to the local conditions.

Predicting the impacts of clearing on vegetation communities: a model-based approach for identifying conservation priorities in Queensland, Australia

ABSTRACT Predicting outcomes is critical for conservation prioritisation. We predicted the areas that are likely to be impacted using a generalised estimating equation from a logistic regression and intersected our model with vegetation community mapping for Queensland, Australia. Under the assumption that areas with a high probability of clearing would eventually be cleared, we identified vegetation communities at risk of transitioning into a more vulnerable status, addressing a critical knowledge gap. Specifically, we identify: 1) areas within the study region's bioregions face the highest risk of forest cover loss; 2) communities may transition to more vulnerable according to their extent-based vulnerability status. Our analysis determined high-risk areas within the study region and vegetation communities vulnerable to changing status. Three clearing scenarios – low, moderate and high – were evaluated. In the low scenario, 0.3 per cent of vegetation communities experienced clearing, with 26 communities changing their status. The moderate scenario impacted 35 per cent of vegetation communities, with 103 communities at risk. In the high scenario (our most aggressive assumption), 45 per cent of vegetation communities overlapped with areas suitable for clearing, affecting the status of 158 communities. We emphaise the need to protect high-risk communities while implementing effective management strategies in areas where clearing poses minimal threat.

Dynamic Shifts in Soil Fungal Functional Group Characteristics across Distinct Vegetation Types during Ecological Restoration in Degraded Red Soil Regions

The red soil region in southern China has become the second-largest soil erosion area after the Loess Plateau. The evolutionary trajectory of soil fungi during vegetation restoration in acidic red soil regions remains a subject of inquiry. The investigation focused on the restoration process of an ecosystem facing intense degradation in the southern regions of China by studying four distinctive vegetation types: barren land (BL), pure Pinus massoniana forest (CF), mixed coniferous (CBF), and broad-leaved forest (BF). The outcomes revealed considerable enhancements in soil properties’ attributes, evident through a gradual reduction in the bulk density of soil (SBD) and a corresponding increment in soil moisture content (MC), total nitrogen (TN), total carbon (TC), total potassium (TK), soil organic matter (SOM), and available potassium (AK) as vegetation restoration advanced. An intriguing trend emerged where the relative abundance of Ascomycota fungi displayed a declining trajectory, whereas Basidiomycota fungi exhibited an ascending trend with the progression of vegetation restoration. Specifically, broad-leaved forests exhibited a significantly greater relative abundance of Penicillium fungi compared to other stages of vegetation restoration. The diversity of soil fungal communities increased in tandem with vegetation restoration. A redundancy analysis illuminated a strong and positive relationship between the abundance of major soil fungi and soil pH, TN, and TC (key influencers of acidic red soil fungal populations). This study provided additional evidence of an elevation in ectomycorrhizal and saprophytic trophic fungi, signifying a transition that enhances the vegetation’s ability to capture water and nutrients. This, in turn, contributes to the overall enrichment and diversity of vegetation communities during the progression of restoration.

An assessment of potential herbivory impacts of a reintroduced marsupial in a predator‐free woodland sanctuary

SummaryFenced sanctuaries that exclude feral predators are critical for threatened species conservation. However, adaptive management of these sanctuaries requires careful consideration of the potential impact herbivore populations free from predation can have on the condition of native vegetation. The Mulligans Flat Woodland Sanctuary in the Australian Capital Territory comprises Critically Endangered box‐gum grassy woodland, threatened orchids, abundant macropods, and a reintroduced population of the Eastern Bettong (Bettongia gaimardi, hereafter “Ngaluda”). To understand how Ngaluda, along with other herbivores, may be potentially impacting vegetation across the sanctuary, we undertook an assessment of indicator plant species. We monitored 106 plots for 13 indicator species (10 species with tuberous roots that the burrowing Ngaluda would be preferentially targeting and three non‐tuberous species). We found that most floristic indicators we investigated – including richness of indicator species and the abundance of lilies – were higher in the Goorooyarroo area of the sanctuary (where Ngaluda are absent and wallabies are rare) compared to the Mulligans Flat area of the sanctuary (where Ngaluda are present and wallabies are abundant), suggesting a negative impact of the overall herbivore assemblage of Mulligans Flat. However, within just Mulligans Flat, some indicators, including the abundance of a common orchid, were significantly lower in areas associated with high Ngaluda activity irrespective of other herbivore densities. We found no instance of Ngaluda presence or higher activity being associated with higher values for any floristic indicator we investigated. These results are consistent with known impacts of abundant herbivores and reintroduced digging marsupials in other predator‐free sanctuaries in Australia. Our results highlight that Ngaluda herbivory may be outweighing any positive effect of their diggings on native vegetation and indicate the need for careful risk mitigation when deciding how critically endangered animals and vegetation communities are managed together in sanctuaries.

Phytosociology and ecological framework of forest tree species in the Toormang Valley, Dir Lower, Hindu Kush Range, Pakistan.

The phytosociological survey was conducted during 2018-2020. The research area was classified into five ecological zones based on habitat, physiognomy and species composition. Pc-Ord software was used for cluster analysis and four vegetation communities were established. The Quercus baloot-Quercus incana community is situated in Sair at an altitude of 1196 (mean ± SE) m altitude with a 14.1 ± 0 slope angle and contains eleven tree species. The Pinus wallichiana- Ailanthus altissima community had a relatively small number of tree species reported in Shakawlie at 1556 (mean ± SE) with a 17.5 ± 0 slope angle. The Pinus wallichiana- Quercus incana community is distributed in Wali Kandao and Mangi Kandao at altitudes of 2030.5 (mean ± SE) m and the slope angle was 19.2 ± 1.4. This community possesses a total of twenty-one tree species and is highly diverse. Similarly, the Populus alba - Platanus orientalis group was present in Banr Pate, with an altitude of 1613 (mean ± SE) m and a 16.3 slope angle. The principal component analysis (PCA) and non-metric multidimensional scaling (NMS) ordination methods were applied to study the relationships between ecological and soil variables with trees species. The NMS ordination of axis 1 was significantly correlated with Sand% (p<0.2), Nitrogen% (p<0.1) and Pb (mg/kg) (r= 0.876751, p<0.05), while the ordination of axis 2 was significantly correlated with Silt% (p<0.2), Sand% (p<0.2), Organic matter% (p<0.2), K (mg/kg) (r=0.882433, p<0.02), Fe (mg/kg)(r=0.614833, p<0.2), Ca (mg/kg) (r=0.721712, p< 0.2) and Zn (mg/kg) (r=0.609545, p<0.2). Similarly, the PCA ordination of axis 1 revealed that it was significantly correlated with phosphorus, calcium and slope angle, while that of axis 2 was significantly correlated with altitude, zinc and manganese.

Diversity of the Ground Cover Crop Nephrolepis Biserrata in Oil Palm Plantations on Various Soil Types

Ground cover crops play an important role in maintaining the ecological balance in oil palm plantations. Nephrolepis biserrata, as a cover crop species, has not been extensively studied, especially in relation to soil type and vegetation level. This study aimed to analyze the distribution and dominance of Nephrolepis biserrata in oil palm plantations on various soil and vegetation levels. This quantitative research was conducted in oil palm plantations in Central Kalimantan Province using a survey method with purposive sampling. Nine treatment combinations of three soil types (Histosols, Ultisols, and Spodosols) and three vegetation levels (low, medium, and high) were tested on 81 test plots. Data analysis includes diversity index (Ĥ), uniformity index (E), dominance index (C), importance value index (INP), and relative dominance (DR). The results of the research show that N. biserrata has good adaptability and dominance as a ground cover crop in the producing crop (TM) phase in oil palm plantations, especially on Spodosol-type soils. Nephrolepis exaltata and Nephrolepis biserrata showed the highest INP in Ultisols (76.65%; 7.64%), Spodosols (48.03%; 82.75%), and Histosols (61.34%; 23.98%). There are no cover crop species that dominate exclusively in all soil types (0.078-0.185). Ultisols have high cover crop diversity (3,107), whereas Spodosols (2,130) and Histosols (2,595) have medium diversity. Ageratum conyzoides (15.08%) and Paspalum dilatatum (10.06%) also had significant INP in all soil types. Different soil conditions influence the number of cover crop vegetation species and communities in oil palm plantations.

Contribution of soil seed banks to vegetation resilience in coastal freshwater wetlands of subtropical Australia

AbstractQuestionsWhat role do soil seed banks play in the resilience of coastal freshwater wetland vegetation communities? How might soil seed bank composition and similarity to standing vegetation drive changes in vegetation expression, particularly given projected changes in climate?LocationSixty wooded coastal freshwater wetlands in southeast Queensland, Australia.MethodsWe surveyed standing vegetation and investigated soil seed bank composition through an 8‐month‐long emergence experiment.ResultsSoil seed bank assemblages were dominated by forb and sedge species (23% exotic), but composition varied throughout the study region. Spatial (north–south) and land‐use (urban–rural) gradients explained some variation in soil seed bank composition. Soil moisture and groundwater dependence also influenced species distributions, particularly for freshwater wetland species. The similarity of soil seed banks to standing vegetation was low. Species present in both extant and soil seed bank assemblages were commonly native wetland taxa, including one salt marsh species (Juncus kraussii).ConclusionsProjected climatic changes will likely drive changes in coastal freshwater wetland vegetation communities through increases in the frequency and intensity of disturbances (e.g., storm surge). Our results suggest that regeneration from soil seed banks could promote four potential scenarios: (1) expansion of weed communities, (2) expansion of salt marsh communities, (3) maintenance and expansion of wetland/terrestrial species, and (4) transformation to an unvegetated open water zone because of reduced regeneration success under changing conditions. These diverse vegetation futures highlight the vulnerability of wooded coastal freshwater wetlands and the need for research and management interventions to maintain their biodiversity and ecosystem services.

Study on the Noise Reduction Effect of Vegetation Communities in Northeast China – Taking Forest Park in Yingkou City as an Example

In this study, the greenland tree and shrub communities in Forest Park, a typical park greenland in Yingkou City, Liaoning Province, were used as the research object to compare the noise reduction of different communities, and to study the degree of noise reduction of the plant communities in summer. The results show that the noise reduction level of vegetation communities in summer is in the following order: M2 cypress + cypress + acacia &gt; M1 poplar + Euphorbia + maple &gt; M3 cypress + yellow thorn rose + ginkgo tree.

Effect of Convergence Plant Selection of Wildflower Mixtures in China on the Plant Invasion

The rapid development of urbanization and urban land-use intensification have substantially reduced biodiversity and ecosystem services. Wildflower mixtures can improve regional biodiversity and habitat heterogeneity by establishing flower-rich habitats and providing multiple ecosystem services, which were considered one of the most favorable landscape ecological restoration technologies approaches. How to design wildflower mixtures to achieve optimal eco-efficiency is currently unclear. In China, wildflower mixture is one of landscape architecture’s most popular methods for establishing herbaceous vegetation. Currently, there is a notable lack of systematic research regarding species selection, and concerns have been raised about the design approach that introduces convergent species, which may potentially become invasive. This research integrated a wildflower mixture design database currently published in China and discovered community composition and construction methods. Based on this, we compared the species composition of wildflower mixtures in China and assessed the potential invasive species. Additionally, we attempted to explore the distribution over time and space, their potential invasion risk, and the main factors influencing species selection through modeling approaches. The results highlighted that species selection of mixture converged with different spatiotemporal attributes and design intentions, despite designed wildflower mixtures in China having gradually increased in recent years. A large number of species from North America and Europe have been causing an increase in potential invasion annually. Furthermore, the research confirmed that the convergence contributes to the homogenization of urban landscape vegetation communities, which leads to biological invasion from the design level, and revealed the possibility that ineffective ecological restoration techniques may cause adverse environmental impacts.

Carbon Stock in Coastal Ecosystems of Tombolos of the White and Baltic Seas

“Blue carbon”, apart from marine humus, includes the carbon (C) stock of coastal ecosystems such as mangroves, saltmarshes, and seagrass meadows, which have been overlooked until recently. Information about the role of coastal wetlands in C sequestration and providing other ecosystem services is still insufficient. In the present study, we assessed the C reserves of soils and vegetation biomass in two complex coastal landscapes (tombolos) located on the coasts of the White and Baltic seas. The soil and plant C stocks were slightly higher at the plot on the Baltic Sea (93.4 ± 46.7 Mg C·ha−1 and 5.22 ± 2.51 Mg C·ha−1, respectively) than at the plot on the White Sea (71.4 ± 38.2 Mg C·ha−1 and 3.95 ± 2.42 Mg C·ha−1, respectively). We attributed the higher values of the C reserved to a warmer climate and less saline water at the plot on the Baltic Sea. Both soil and plant C showed high heterogeneity due to geomorphological complexity and differences in vegetative communities. The Phragmites australis community showed the highest plant biomass and, in some places, high soil C reserves. Allochthonous C contributed to the soil C stock at the site on the White Sea. Though P. australis sequestered more C than other communities, its effect on ecosystem services was mostly negative because the invasion of reeds reduced the biological diversity of the marshes.

Driving Factors Influencing Soil Microbial Community Succession of Coal Mining Subsidence Areas during Natural Recovery in Inner Mongolia Grasslands.

Soil microorganisms significantly influence the energy flow and material cycle of soil ecosystems, making them highly susceptible to environmental changes, such as those induced by mining activities. Studying the succession of soil microbial communities after mining subsidence is crucial for comprehending the significance of soil microbes in the natural recovery process following subsidence. Therefore, the soil properties, vegetation communities, and soil microbial communities of the subsidence area, as well as unexploited areas, were analyzed during the natural restoration process (1, 2, 5, 10, and 15 years). The results demonstrate that mining subsidence has a significant impact on the aboveground vegetation community, soil properties, and microbiological community. Following an extended period of natural recovery, a new stable state has emerged, which differs from that observed in non-subsidence areas. The total nitrogen, nitrate nitrogen, and ammonium nitrogen amounts may be key factors driving the natural recovery of bacterial communities, and total potassium and available potassium may be key factors driving the natural recovery of fungal communities. The natural recovery mechanism of soil microorganisms was analyzed along with the changes related to vegetation and soil physicochemical properties. The mechanism was explained from three perspectives, namely, plant-led, soil-led, and soil-microbial-led, which could provide a theoretical basis for the natural restoration of grassland ecosystems and provide guidance for the treatment of coal mining subsidence areas.

Optimization of a soil type prediction method based on the deep learning model and vegetation characteristics

The structure and composition of forest vegetation plays an important role in different ecosystem functions and services. This study aimed to identifying soil types based on vegetation characteristics using a deep learning model in the High Conservation Value (HCV) area of Central Kalimantan, spanning 632.04 hectares. The data on vegetation were collected using a combination method between line transect and quadratic plots were placed. The development of a deep learning model was based on the results of a vegetation survey and the processing of aerial photos using the Feature Classifier method. The results of applying a deep learning model could provide a relatively accurate and consistent prediction in identifying soil types (Entisols 62%, Spodosols 90%, Ultisols 90% accuracy). The composition of vegetation community in Ultisols was dominated of seedling and tree (closed canopy), meanwhile in Entisols and Spodosols was dominated of seedling and sapling (dominantly open canopy). Ultisols exhibited the highest species richness (57 species), followed by Spodosols (31 species) and Entisols (14 species). Ultisols, Entisols, and Spodosols displayed even species distribution(J' close to 1) without dominance of certain species(D &lt; 0.5). The species diversity index was at a low to moderate level(H' &lt; 3), while the species richness index remained at a very low level(D_mg &gt; 3.5).

Drivers of contemporary and future changes in Arctic seasonal transition dates for a tundra site in coastal Greenland.

Climate change has had a significant impact on the seasonal transition dates of Arctic tundra ecosystems, causing diverse variations between distinct land surface classes. However, the combined effect of multiple controls as well as their individual effects on these dates remains unclear at various scales and across diverse land surface classes. Here we quantified spatiotemporal variations of three seasonal transition dates (start of spring, maximum normalized difference vegetation index (NDVImax ) day, end of fall) for five dominating land surface classes in the ice-free Greenland. Using a distributed snow model, structural equation modeling, and a random forest model, based on ground observations and remote sensing data, we assessed the indirect and direct effects of climate, snow, and terrain on seasonal transition dates. We then presented new projections of likely changes in seasonal transition dates under six future climate scenarios. The coupled climate, snow cover, and terrain conditions explained up to 61% of seasonal transition dates across different land surface classes. Snow ending day played a crucial role in the start of spring and timing of NDVImax . A warmer June and a decline in wind could advance the NDVImax day. Increased precipitation and temperature during July-August are the most important for delaying the end of fall. We projected that a 1-4.5°C increase in temperature and a 5%-20% increase in precipitation would lengthen the spring-to-fall period for all five land surface classes by 2050, thus the current order of spring-to-fall lengths for the five land surface classes could undergo notable changes. Tall shrubs and fens would have a longer spring-to-fall period under the warmest and wettest scenario, suggesting a competitive advantage for these vegetation communities. This study's results illustrate controls on seasonal transition dates and portend potential changes in vegetation composition in the Arctic under climate change.