Vegetation Changes Research Articles

Reconstructing the long-term ecological history of Long Island, Furneaux Group (Bass Strait), Lutruwita/Tasmania

The Bass Strait islands are the elevated remnants of a now-submerged continental land bridge that connected the mainland of Australia to Lutruwita/Tasmania during low sea level phases of the Quaternery period. The Furneaux Group is made up of around 100 islands, harbouring a rich diversity of plants derived from glacial refugia and stepping-stone dispersal as millennial-scale climate change altered the land and seascape configuration of the land bridge. Despite the region’s significance, long-term ecological and environmental dynamics of most of these islands remain poorly known. We present the first palaeoecological study of Long Island, a small granite island of the Furneaux group, currently covered by extensive grasslands in the west and patches of forest and woodland in the east and north of the island. We use decadal to centennial-scale resolution palaeoecological evidence for vegetation, animal and fire dynamics, alongside historical accounts of vegetation changes inferred from aerial photo analysis, to develop a comprehensive record of the island’s long-term ecology. Results show that grasslands have been an important feature of the island for at least the last 1000 years, and are reminiscent of Last Glacial Maximum grasslands of the now-submerged Bassian Plain. Both aerial photo analysis and the palaeoecological record show increases in forest cover on the island’s eastern corner over the past four decades. We discuss these ecological dynamics in the context of environmental and climatic shifts. This study emphasises the importance of palaeoecological studies, specifically their value in understanding modern ecosystems in their historic context. This data is critical in understanding the island’s current landscape and how this might change into the future.

Gopher Tortoise (Gopherus polyphemus) burrow associate communities are depauperate in modified landscapes

Abstract The Gopher Tortoise (Gopherus polyphemus) is considered a keystone species because its burrows provide refuge for an entire suite of other species (hereafter burrow associates) that occupy the habitats in which it resides. The Gopher Tortoise has declined across its range in large part due to habitat loss and land use change resulting in burrow abandonment or reduced burrow density, and the concomitant negative effects on burrow associate diversity have been well documented. However, under scenarios where Gopher Tortoise populations persist in modified habitat, the effect on community associates has received considerably less attention. In such instances, vegetation changes drive the loss of associate species, not the lack of suitable burrows. Here, we evaluated associations between Gopher Tortoise burrows and vertebrate burrow associates within test ranges and forested sites on Eglin Air Force Base, Florida. Specifically, we (1) determined how vegetation composition varies between forested sandhills and military test ranges, and (2) compared species richness, diversity, and community composition of burrow associates between habitats. We found that vegetation composition surrounding Gopher Tortoise burrows is highly variable, but in general test ranges had a simpler habitat structure and less diverse native plant communities than forested sites. As a result, we show that although military test range sites contain Gopher Tortoise burrows at comparable or higher densities than sites in natural longleaf pine sandhills, the community of vertebrate burrow associates in test range sites appears to be depauperate. Our results highlight that concern over habitat modifications may be warranted even in instances where Gopher Tortoise populations appear to be persisting. In the context of management that seeks to be beneficial to a wide array of burrow associates, efforts aimed at bolstering Gopher Tortoise populations in forested sandhills would be most prudent.

Global urban greening and its implication for urban heat mitigation

Urban vegetation provides essential ecosystem services and benefits to support biodiversity and human well-being in urban areas. However, the dynamic trends, driving factors, and their implications to urban heat mitigation at the global scale remain largely unclear. Here, we used a high-resolution enhanced vegetation index (EVI) dataset to examine the vegetation dynamics in 11,235 urban areas worldwide, identify the driving factors behind its changes, and estimate the potential urban heat mitigation benefits of these changes. We found that 40.75% urban areas (1.51 Mha) evidenced a greening trend (showing increasing EVI), in contrast to 49.60% urban areas showing browning (decreasing EVI). Notably, urban centers in both developed and developing countries contribute to this greening trend. We, nevertheless, found significant spatial disparities in this greening trend, with cities in the Global North showing higher greening ratios than those in the Global South. The driving factors of urban vegetation change trend lead to significant differentiation in and around urban areas. The rapid increase in urbanization intensity and the negative effects of nitrogen deposition are the dominant factors leading to vegetation browning in urban peripheries. However, nitrogen deposition and urbanization intensity have shown positive effects on vegetation greening within urban centers. Crucially, compared to areas with vegetation browning or no significant change, vegetation greening areas have a more significant cooling effect, potentially mitigating the urban heat island effect, especially during summer daytime. Our findings highlight the importance of enhancing urban vegetation greening to promote equitable urban development and ensure effective climate change mitigation.

Changes in climate drove vegetation and land use dynamics at the onset of farming in Europe

Abstract Here we present the first high-resolution continuous palaeoecological study from Greece covering the Mesolithic–Neolithic transition at Limni Zazari, a small lake in western Macedonia. We study how interactions between vegetation and climate might have affected the introduction of agriculture to Europe ca. 8500 years ago. We found that mixed deciduous oak woodlands established around the lake once moisture availability began to increase at ~10,300 cal yr BP. Between 8600 and 8000 cal yr BP, climate change, causing drier conditions, led to the decline of the woodlands and the expansion of steppe and grassland vegetation. Concurrently, in agreement with the archaeological record, pollen indicative of arable and pastoral farming indicate the onset of Neolithic farming. After 8000 cal yr BP the forest composition changed, with a major expansion of pine forests and increases in disturbance-adapted trees like Ostrya and Fagus. This change might be linked to changes in moisture availability, but it is likely that land use also facilitated these shifts. We conclude that the introduction of Neolithic farming was advantaged by climate-induced vegetation changes. While the vegetation structure around Zazari was very sensitive to changes in moisture, early anthropogenic disturbances led to changes in the vegetation composition that are still important today.

Multiscale wildfire and smoke detection in complex drone forest environments based on YOLOv8

Global climate change has triggered frequent extreme weather events, leading to a significant increase in the frequency and intensity of forest fires. Traditional fire monitoring methods such as manual inspections, sensor technologies, and remote sensing satellites have limitations. With the advancement of drone technology and deep learning, using drones combined with artificial intelligence for fire monitoring has become mainstream. This paper proposes an improved YOLOv8-based model that incorporates local convolution instead of full convolution in the C2F module and integrates the EMA module to enhance the feature channel interaction modeling capability and contextual information utilization, thereby reducing model complexity and increasing efficiency. Additionally, in order to address the risk of false positives and missed detections caused by vegetation, terrain, and lighting changes in forests, we have introduced the AgentAttention module in the Backbone. This module combines Softmax and linear attention to optimize feature extraction, improving the model’s accuracy and robustness. Furthermore, in order to tackle the challenges of detecting flames and smoke at different scales and angles, we have designed the BiFormer module, which adaptively fuses global and local features, significantly enhancing the model’s multi-scale and multi-angle detection capability. Experimental results show that the improved model achieves Precision and Recall of 93.57% and 88.51%, respectively, representing improvements of 5.05% and 2.72% over the original model. It also optimizes FPS, GFLOPs, and Params by 14.3%, 25%, and 19.7%, respectively. This research has significant application prospects in forest fire early warning, emergency response, and loss reduction, while also providing strong technical support for forest resource protection and public safety.

Hemiparasitic plants facilitate ecological restoration of encroached European grasslands.

Species-rich grasslands of temperate Europe are threatened by the spread and increasing dominance of the rhizomatous grass Calamagrostis epigejos. Native hemiparasitic Rhinanthus species have been proposed as biocontrol to suppress C. epigejos, but experimental evidence is limited. We conducted a series of experiments at 21 grassland sites in Central Europe encroached by C. epigejos to test the effects of Rhinanthus on C. epigejos and on plant and arthropod communities and compare them to the effects of mowing applied once or twice a year. Rhinanthus suppressed Calamagrostis epigejos significantly more than mowing. Mowing frequency and Rhinanthus sowing had synergistic effects, leading to an average 75% reduction of C. epigejos biomass in Rhinanthus plots that were mown twice during the three-to four-year experimental period. The effect was more pronounced at sites in dry climates. Both Rhinanthus and mowing significantly increased plant diversity. Rhinanthus plots mown twice changed most rapidly towards the target grassland vegetation. The abundance and species richness of arachnids and Auchenorrhyncha were generally higher in abandoned plots than in plots with active management. Rhinanthus plots harboured fewer grass-feeding insects but more forb-associated herbivorous Auchenorrhyncha and Heteroptera species and several heliophilous spiders. Our experiment showed that Rhinanthus spp., in combination with mowing, is an efficient and widely applicable method to reverse the encroachment of C. epigejos into grasslands and restore the diversity of infested plant communities. Active management measures also trigger a species turnover of arthropod communities, reflecting changes in grassland vegetation and arthropod guild species pools.

Greening of Svalbard in the twentieth century driven by sea ice loss and glaciers retreat

The greening of previously barren landscapes in the Arctic is one of the most relevant responses of terrestrial ecosystem to climate change. Analyses of satellite data (available since ~1980) have revealed a widespread tundra advance consistent with recent global warming, but the length is insufficient to resolve the long-term variability and the precise timing of the greening onset. Here, we measured plant-derived biomarkers from an Arctic fjord sediment core as proxies for reconstructing past changes in tundra vegetation during the transition from the Little Ice Age to modern warming. Our findings revealed a rapid expansion of the tundra since the beginning of the twentieth century, largely coinciding with the decline of summer sea ice extent and glacier retreat. The greening trend inferred from biomarker analysis peaked significantly in the late 1990s, along with a shift in the tundra community towards a more mature successional stage. Most of these signals were consistent with the biomolecular fingerprints of vascular plant species that are more adapted to warmer conditions and have widely expanded in proglacial areas during recent decades. Our results suggest that the greening of Arctic fjords may have occurred earlier than previously thought, improving our mechanistic understanding of vegetation-climate-cryosphere interactions that will shape tundra vegetation under future warming projections.

Composition of soil fungal communities and microbial activity along an elevational gradient in Mt. Jiri, Republic of Korea.

Approximately 64% of the Republic of Korea comprises mountainous areas, which as cold and high-altitude regions are gravely affected by climate change. Within the mountainous and the alpine-subalpine ecosystems, microbial communities play a pivotal role in biogeochemical cycling and partly regulate climate change through such cycles. We investigated the composition and function of microbial communities, with a focus on fungal communities, in Republic of Korea's second tallest mountain, Mt. Jiri, along a four-point-altitude gradient: 600-, 1,000-, 1,200-, and 1,400-m. Soil pH and elevation were negatively correlated, with soils becoming more acidic at higher altitude. Of the five soil enzyme activities analyzed, cellobiohydrolase, β-1,4-glucosidase, and β-1,4-xylosidase activity showed differences among the elevation levels, with lower activity at 600 m than that at 1,400 m. Soil microbial biomass correlated positively with increasing elevation and soil water content. The decrease in β-1,4-N-acetylglucosaminidase suggests a reduction in fungal biomass with increasing altitude, while factors other than elevation may influence the increase in activity of the cellobiohydrolase, β-1,4-glucosidase and β-1,4-xylosidase. Fungal alpha diversity did not exhibit an elevational trend, whereas beta diversity formed two clusters (600-1,000 m and 1,200-1,400 m). Community composition was similar among the elevations, with Basidiomycota being the most predominant phylum, followed by Ascomycota. Conversely, among the fungal communities at 1,000 m, Ascomycota was the most dominant, possibly due to increased pathotroph percentage. Elevational gradients induce changes in soil properties, vegetation, and climate factors such as temperature and precipitation, all of which impact soil microbial communities and altogether create a mutually reinforcing system. Hence, inspection of elevation-based microbial communities can aid in inferring ecosystem properties, specifically those related to nutrient cycling, and can partly help assess the oncoming direct and indirect effects of climate change.

Impact of Deep-Rooted Vegetation on Deep Soil Water Recharge in the Gully Region of the Loess Plateau

To investigate the impacts of vegetation change on deep soil water recharge, it is essential to identify the sources of deep soil water and deep drainage. The combination of stable and radioactive water isotopes is an effective method for studying deep vadose zones, though it has been rarely applied in complex gully areas. In this study, we measured δ2H, δ18O, and 3H in soil water under long-term natural grassland and C. korshinskii on the same slope. Both natural grassland and C. korshinskii plots received deep soil water from rainfall during the rainy season; however, the replenishment thresholds for soil water at depths of 2–10.4 m differed between the two vegetation types, corresponding to rainfall intensities of ≥20 mm and ≥50 mm, respectively. Following the conversion of natural grassland to C. korshinskii vegetation, the rate of soil water storage deficit increased by 46.4 mm yr−1, and deep drainage shifted from 39.6 mm yr−1 to 0 mm yr−1. Deep-rooted vegetation significantly depletes soil water to meet transpiration demands, thus hindering rainfall recharge. These findings have important implications for water and land resource management, especially in areas undergoing significant vegetation changes.

Spatiotemporal Variation and Driving Analysis of Net Primary Productivity of Vegetation in Southern Part of Taihang Mountain, China

The net primary productivity of vegetation (NPP) is an important index to evaluate the carbon sequestration capacity of vegetation and land use change. Using MOD17N3HGF NPP data, climate data and night-time light data from 2000 to 2020, this study explored the relationship between NPP and urban expansion, land use and climate change in the Southern Part of Taihang Mountain through brightness gradient method, trend analysis, partial correlation analysis and contribution analysis. It aims to provide information support for urban and rural planning and ecological management in this region. Key findings include: Over the past 20 years, NPP in mountain areas has shown an overall fluctuating upward trend, with an "N" pattern related to altitude. The human activity area expanded by 9.9%, with expansion of highly active areas holding back NPP growth and moderately active areas contributing to it. The trend of climate change is gradually warming and wetting, and the correlation between precipitation and NPP is strong, while the correlation between temperature and NPP is weak. Compared with human activities (19.9%), precipitation was the main driver of NPP change, contributing significantly up to 79.5%. In the past 20 years, the ecological quality of the south Taihang Mountain region has improved significantly and actively responded to climate change, but human activities have led to spatial and temporal ecological differences.

Spatiotemporal Changes in Evapotranspiration and Its Influencing Factors in the Jiziwan Region of the Yellow River from 1982 to 2018

Evapotranspiration (ET) is a critical process in the interaction between the terrestrial climate system and vegetation. In recent years, ET has undergone significant changes in the Jiziwan region of the Yellow River Basin, primarily due to the implementation of ecological restoration programs and the dual impacts of climate change. As a result, hydrological cycle processes have been profoundly affected, making it crucial to accurately capture trends in ET and its components, as well as to identify the key drivers of these changes. In this study, we first systematically analyzed the dynamic evolution of ET and its components in the Jiziwan of the Yellow River area between 1982 and 2018 from the perspective of land use change. To achieve accurate ET simulations, we introduced a multiple linear regression algorithm and quantitatively evaluated the specific contributions of five climate factors, including precipitation, temperature, wind speed, specific humidity, and radiation, as well as the normalized difference vegetation index (NDVI), a vegetation factor, to ET and its components. On this basis, we explored the combined influence mechanism of climate change and vegetation change on ET in detail. The results revealed that the structure of ET in the Jiziwan of the Yellow River area has changed significantly and that vegetation evapotranspiration has gradually replaced soil evaporation, occupies a dominant position, and has become the main component of ET in this area. Among the many factors affecting ET, the contribution of climate change is the most significant, with an average contribution rate of approximately 59%. Moreover, the influence of human activities on total ET and its components is also high. The factors that had the greatest impact on total ET, soil evaporation, and vegetation transpiration were precipitation, radiation, and the NDVI, respectively. In terms of spatial distribution, the eastern part of Jiziwan was more significantly affected by environmental changes, and the trends of the ET changes were more dramatic. This study not only enhances our scientific understanding of the changes in ET and their driving mechanisms in the Jiziwan area of the Yellow River but also provides a solid scientific foundation for the development of water resource management and ecological restoration strategies in the region.

Modeling Climate-Driven Vegetation Changes Under Contrasting Temperate and Arid Conditions in the Mediterranean Basin.

This study investigates climate change impacts on spontaneous vegetation, focusing on the Mediterranean basin, a hotspot for climatic changes. Two case study areas, Monti Sibillini (central Italy, temperate) and Sidi Makhlouf (Southern Tunisia, arid), were selected for their contrasting climates and vegetation. Using WorldClim's CMCC-ESM2 climate model, future vegetation distribution was predicted for 2050 and 2080 under SSP 245 (optimistic) and 585 (pessimistic) scenarios. Two spectral indices, NDVI (temperate area) and SAVI (arid area), served as vegetation proxies, classified into three classes using K-means (NDVI: high = mainly associated with woodlands, medium = shrublands, continuous grasslands and crops, low = discontinuous grasslands, bare soil, and rocks; SAVI: high = mainly associated with woods, olive trees, and crops, medium = shrublands and sparse olive trees, low = bare soil and saline areas). Classes validated with ESA WorldCover 2020 data and sampled via 1390 presence-only points. A set of 33 environmental variables (topography, soil, and bioclimatic) was screened using Pearson correlation matrices, and predictive models were built using four algorithms: MaxEnt, Random Forest, XG Boost, and Neural Network. Results revealed increasing temperatures and declining precipitation in both regions, confirming Mediterranean climate trends. Vegetation changes varied by area: in the temperate area, woodlands and shrublands were stable, but discontinuous grasslands expanded. In the arid area, woodlands gained suitable habitat, while bare soil declined under the pessimistic SSP 585 scenario. Both areas showed an upward shift for shrublands and grasslands. The models indicated significant shifts in areal distribution and environmental conditions, affecting habitat suitability and ecosystem dynamics. MaxEnt emerged as the most reliable algorithm for small presence-only datasets, effectively predicting habitat suitability. The findings highlight significant vegetation redistribution and altered ecosystem dynamics due to climate change, underscoring the importance of these models in planning for future ecological challenges.

Effects of pasture‐burning management on anuran communities in subtropical Brazilian grasslands

AbstractAnthropogenic fire is a worldwide event that affects many ecosystems and organisms. In Southern Brazil, grassland management with fire has been highly employed since the mid‐18th century. Although the practice is regulated by federal law (prescribed fire), there is no detailed information about the impacts of this practice on the small, non‐volant fauna. We evaluated the effect of fire management on anuran species richness and community composition in Brazilian grassland areas that have adopted this practice for more than 15 years. Our results show that burning practices lead to a reduction of anuran richness. About 37% of the species occur exclusively in sites free of fire. Sites with fire management have low densities of taller grass and shrubs, which could reduce habitat availability for some anuran species. Nestedness and turnover components of beta diversity did not differ within and between treatments, but there was a tendency for a nestedness organization of the community in burned sites, suggesting that sites with fire management are a subsample of sites where fire is absent. Our results pointed out that prescribed fire practices have potentially negative effects on the anuran diversity. These results suggest that the changes in vegetation, in particular percentages of shrub cover, affect habitat suitability for some species. Therefore, anuran communities tend to become less diverse and lack arboreal species where fire occurs.Abstract in Portuguese is available with online material.

Spatiotemporal changes of vegetation in the northern foothills of Qinling Mountains based on kNDVI considering climate time-lag effects and human activities

Spatiotemporal changes of vegetation in the northern foothills of Qinling Mountains based on kNDVI considering climate time-lag effects and human activities

Independent Trends of Mountain Vegetation and Soil Properties Over 40 Years of Environmental Change

ABSTRACTQuestionsAlthough mountain ecosystems are key in providing numerous contributions to people, they are affected by environmental changes. The European Alps, in particular, although shaped by human land use for millennia, suffer pronounced impacts of climate change combined with continued land‐use changes and atmospheric nitrogen deposition. As a core component of ecosystem functioning, the soil–vegetation interface is especially sensitive to these environmental changes, and it is therefore crucial to understand its response. Although several studies have demonstrated the impacts of environmental change on vegetation or soil individually, it remains largely unknown whether they respond synchronously.LocationMontane and subalpine grasslands of the Western Swiss Alps.MethodsWe analysed changes and correlations of ecological indicators of vegetation and soil properties after 40 years in 86 re‐surveyed semi‐permanent plots.ResultsEcological indicators of vegetation releves changed, driven by an increase of species adapted to alkaline conditions and mowing or grazing. By contrast, we detected neither a trend of thermophilisation, nor an increase of nutriphilous species or those adapted to hemeroby. Organic carbon, nitrogen, organic matter content, carbon‐to‐nitrogen ratio and pH increased in the soil. Yet, these changes of vegetation and soil were so far independent of each other.ConclusionsOur findings suggest that mountain vegetation and soil have so far changed asymmetrically with potential knock‐on effects in the decades to come with implications for the conservation of mountain ecosystems and our capacity to predict their future trajectory.

Half a Century of Temperate Non-Forest Vegetation Changes: No Net Loss in Species Richness, but Considerable Shifts in Taxonomic and Functional Composition.

In recent decades, global change and local anthropogenic pressures have severely affected natural ecosystems and their biodiversity. Although disentangling the effects of these factors is difficult, they are reflected in changes in the functional composition of plant communities. We present a comprehensive, large-scale analysis of long-term changes in plant communities of various non-forest habitat types in the Czech Republic based on 1154 vegetation-plot time series from 53 resurvey studies comprising 3909 vegetation-plot records. We focused not only on taxonomic diversity but also on the functional characteristics of communities. Species richness of most habitat types increased over time, and taxonomic and functional community composition shifted significantly. Habitat specialists and threatened species became less represented in plant communities, indicating a decline in habitat quality. The spread of trees, shrubs, tall herbaceous plants, strong competitors, and nutrient-demanding species in all non-forest habitats, coupled with the decline of light-demanding species, suggests an effect of eutrophication and natural succession following the abandonment of traditional management. Moreover, we identified specific trends in certain habitats. In wetlands, springs, and mires, moisture-demanding species decreased, probably due to drainage, river regulations, and increasing drought resulting from climate change. Dry grasslands, ruderal, weed, sand, and shallow-soil vegetation became more mesic, and successional processes were most pronounced in these communities, suggesting a stronger effect of abandonment of traditional management and eutrophication. In alpine and subalpine vegetation, meadows and mesic pastures, and heathlands, insect-pollinated species declined, and the proportion of grasses increased. Overall, these functional changes provide deep insights into the underlying drivers and help conservationists take appropriate countermeasures.

Distribution and sources of modern pollen in a shallow lake, eastern China: Revealing their relationships with land cover and aquatic plants.

Pollen sources and deposition processes in shallow lakes in densely populated plain areas are complicated, more modern studies are needed to establish the relationship between pollen and vegetation, so as to provide accurate indicators for environmental reconstruction. In this study, 23 surface sediments were collected from Changdang Lake in the Taihu Lake basin (covering inlets, outlets, and open water areas) for discussing the indicative significance of pollen on regional land cover and aquatic plants in the lake. The results show that the terrestrial pollen assemblages in surface sediments can reflect the main vegetation types in the watershed. However, there are significant differences in the source and input mode of the major pollen taxa. All life forms of aquatic plants show a good spatial correspondence with pollen signals, and these signals have good potential for the reconstruction of lake environment. The pollen concentration increases from inlets to outlets, mainly affected by the hydrologic dynamics inside lake. The variations of T/A ratio (the ratio of terrestrial pollen to aquatic pollen proportions) indicate that the central lacustrine sediments are more suitable for reconstructing past watershed vegetation and climate changes. The anthropogenic P/V ratio (pollen proportions/corresponding land cover proportions) maintains a stable value (~0.5) in eastern China, and proves that the pollen of cultivated plants and anthropochores can be used to assess the extent of human impacts on natural landscapes.

A continental record of Early Cretaceous (Aptian) vegetation and climate change based on palynology and clay mineralogy from the North China Craton

A continental record of Early Cretaceous (Aptian) vegetation and climate change based on palynology and clay mineralogy from the North China Craton

Temperature Overshoot Would Have Lasting Impacts on Hydrology and Water Resources

AbstractModels of climate change impacts could be missing significant risks to hydrologic and water infrastructure systems through a shared feature: the idea that temperatures rise monotonically. By contrast, temperature overshoot pathways describe non‐monotonic warming trajectories, in which global temperatures first exceed a given target before declining to that target. Risks from overshoot pathways are qualitatively different from risks associated with monotonic warming trajectories, and are likely underestimated in current research and policy. Models suggest overshoot may be almost unavoidable if the more stringent Paris Agreement target limiting warming to 1.5°C over preindustrial levels is to be met by 2100. While overshoot has been relatively widely described in the climate literature, the impacts of overshoot on individual system characteristics have not. We suggest that failure to consider disparities between monotonic and overshoot warming impacts on hydrology and water resources presents particular risks due to divergent adaptation needs. Processes with decadal hysteresis are especially vulnerable. These include glacial contributions to streamflow; hydrologic consequences of vegetation change; altered groundwater; higher water use for fossil fuel combustion and carbon dioxide removal; and water infrastructure and policy that depends on climate conditions. We argue that risks of overshoot cannot be fully captured in current integrated assessment models and that overshoot needs to be specifically evaluated to adequately characterize risk in the water system. We consider how current modeling tools could be adapted to evaluate overshoot consequences, but also recognize that decisions must be made even without perfect knowledge.

Phragmites australis elevated concentrations of soil-bound heavy metals and magnetic particles in a typical urban plateau lake wetland, China.

Vegetation change significantly altered the hydrological processes and soil erosion within riparian ecosystems. It is unclear how change in managed vegetation types affect the geochemical behavior of heavy metals (HMs) and magnetic particles in karst riparian areas. Two soil depths of 0-20cm and 20-40cm were taken in alien species Phragmites australis (P. australis), native species Juncus effuses and Schoenoplectus tabernaemontan in a typical urban plateau Lake wetland, Caohai lake, China. Low-frequency mass magnetic susceptibility (χLF), anhysteretic remanent susceptibility (χARM), isothermal remanent magnetization, Cd, Cr, Cu, Sb, Ni and Zn were determined. Compared with Juncus effuses and Schoenoplectus tabernaemontani, P. australis habitat had the higher values of HMs, χLF, χARM, and isothermal remanent magnetization in top-soils. Frequency-dependent magnetic susceptibility ranged from 4.84% to 10.87% in top-soils and 6.82%-9.95% in sub-soils, lithogenic/pedogenic factors mainly masked the contribution of anthropogenic factors to magnetic signal enhancement. The correlation between variations of Cu and Sb with χARM and isothermal remanent magnetization was found to be significant in top-soils, but not in sub-soils. P. australis tended to promote the enrichment of HMs and enhancement of magnetic signal, the impact of P. australis expansion on the distribution of soil HMs and magnetic particles in Caohai riparian wetland should be not disregarded.