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Terrestrial ecosystems heavily depend on vegetation, which responds to carbon dioxide (CO2) fertilization in hot and humid regions. The subtropical humid karst region is a hot and humid region; whether and to what extent CO2 fertilization affects vegetation changes in such regions remains unclear. In this study, we investigated the degree to which CO2 fertilization influences vegetation changes, along with their spatial and temporal differences, in the subtropical humid karst region using time-lag effect analysis, a random forest model, and multiple regression analysis. Results showed that CO2 fertilization plays an important role in vegetation changes, exhibiting clear spatial variations across different geomorphological zones, with its degree of influence ranging mainly between 11% and 25%. The highest contribution of CO2 fertilization was observed in the karst basin and non-karstic region, whereas the lowest contribution was found in the karst plateau region. Previous studies have primarily attributed vegetation changes in subtropical humid karst region to ecological engineering, leading to an overestimation of its contribution to these changes. The findings of this study enhance the understanding of the mechanism of vegetation changes in humid karst region and provide theoretical and practical insights for ecological and environmental protection in these regions. [ABSTRACT FROM AUTHOR]

This research used the Sentinel-1 and Sentinel-2 data to map forest canopy cover. The main aim of this study is to assess the capability and value of SAR and Optical image data for mapping, estimating, and monitoring forest canopy cover and its parameters in the Ngel Nyaki Forest Reserve in the Mambilla Plateau, Taraba State, Nigeria. The spatial distribution pattern of forest vegetation cover between 2015 and 2021 was analyzed using a random forest model with Sentinel-1 and maximum likelihood for Sentinel-2 data and the relationship between the biophysical parameter Leaf-Area-Index (LAI) and the spectral indices. The results show changes in canopy cover derived from Sentinel-1 and Sentinel-2 with varying canopy cover frequencies, indicating a decrease from 34% to 27% and 32% to 25% from 2015 to 2021, respectively. The basal area per acre (BA/ac) ranges from 30 to 170 square feet/acre, with a mean of 62.82 square feet/acre and a standard deviation of 37.77 square feet/acre. Moreover, the analysis of biophysical parameters shows that the LAI for the entire forest area was 3.88 in 2015, indicating a relatively dense canopy with substantial leaf cover, while the LAI value of 3.82 in 2021 suggests a slight decrease in leaf area density. [ABSTRACT FROM AUTHOR]

The grassland ecosystem in the Inner Mongolia Autonomous Region (IMAR) serves as a vital ecological barrier in northern China, and the vegetation productivity in the grasslands exhibits considerable temporal and spatial variations. However, few studies have examined the long-term variations in the NPP in the IMAR and quantified the effects of natural factors and human activities on the NPP. The study modeled the net primary productivity (NPP) of the IMAR's grasslands using the Carnegie–Ames–Stanford approach (CASA) model and employed linear regression, trend analysis, and spatial statistics to analyze the spatio-temporal patterns in vegetation productivity and explore the impact on the NPP of natural and socio-economic factors over the past two decades. The results reveal that the average NPP value from 2001 to 2021 was 293.80 gC∙m−2 a−1, characterized by spatial clustering of a relatively high NPP in the east, a low NPP in the west, and an annual increase of 3.26 gC∙m−2 over the years. The NPP values varied significantly across different vegetation cover types, with meadows having the highest NPP, followed by typical steppe and desert grasslands. The spatial distribution pattern and temporal changes in the grassland productivity are the result of both natural factors and human activities, including topographical properties and socio-economic indicators such as gross domestic product, night-time light, and population. The results for the NPP in the IMAR were based solely on the CASA model and, therefore, to achieve improved data reliability, exact measurements in real field conditions will be conducted in the future. The findings from the spatial clustering and temporal trajectories of the NPP and the impacts from the factors can provide useful guidance to planning grassland vegetation protection policies for the IMAR. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Resources & Ecology is the property of Journal of Resources & Ecology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The changes in the grassland vegetation that have occurred over the last almost 100 years on the northeastern Adriatic island of Plavnik (Croatia) were studied. For this purpose, 29 phytosociological relevés of standard plot size were collected using the Braun-Blanquet phytosociological approach and compared with those of 100 years ago. With the aim of defining the differences among the communities and identifying the main environmental gradients, cluster analysis (Ward's method on a Chord distance matrix) and non-metric multidimensional scaling ordination were applied. Taxa score-weighted means of the Ellenberg-type indicator values of main environmental variables were used to assess ecological differences among communities, and disturbance-related indicator values were calculated to assess the disturbance regime in shaping plant communities. According to the syntaxonomic framework for the grassland associations, three associations and two subassociations were found. Among them the Festuco valesiacae-Poetum bulbosae (Poetalia bulbosae, Poetea bulbosae), the Helichrysetum italici salvietosum officinalis (Scorzoneretalia villosae, Festuco--Brometea), and the Hedypnoido rhagadioloidis-Asphodeletum ramosi were proposed as new. The Festuco valesiacae- - Poetum bulbosae documents for the first time, based on phytosociological data, the occurrence of the Poetea bulbosae in Croatia. Three associations were considered extinct, possibly as a result of changes in grazing pressure and type. [ABSTRACT FROM AUTHOR]

Maintaining biodiversity in agricultural landscapes is a major challenge for environmental protection in Europe. Vineyards rely heavily on agrotechnical interventions such as herbicide use and tillage for weed control, which affect biodiversity and can lead to soil erosion and resistant weed populations. The fragmentation of agricultural landscapes affects biodiversity by altering community composition and often reducing plant population sizes and genetic diversity. However, it can also increase the abundance of certain species and enhance population resilience to environmental change. Vineyards can support high levels of biodiversity and provide ecosystem services due to their semi-natural habitat structure. This research evaluates vegetation biodiversity using phytosociological relevés in different vineyards. Our results show that species richness and biodiversity are significantly influenced by vineyard age and management type. This study highlights differences in the representation of plant functional groups, with perennial taxa in grassy inter-row contributing to anti-erosion functions and serving as food sources for pollinators. The root zone around vine trunks shows an increase in invasive species with vineyard age, posing a risk to the agroecosystem. Vineyards predominantly follow a ruderal ecological strategy, using nutrients and light efficiently, while tolerating management disturbances. Understanding these dynamics is critical for developing sustainable vineyard management practices that support biodiversity and ecological resilience, counteract the homogenization of agricultural landscapes, and promote the coexistence of viticulture and species-rich ecosystems. [ABSTRACT FROM AUTHOR]

Complete eradication of invasive plants is often infeasible but in some cases it is possible to reduce the invader to low levels with reduced ongoing management costs, referred to as functional eradication. Non-native Phragmites australis has challenged land managers across North America but functional eradication may yet be possible in some scenarios. Here we present data from Chesapeake Bay brackish tidal wetlands where two approaches to Phragmites management (long-term, continuous management and short-term, non-continuous management) were used. We demonstrate that the application of herbicides will lead to the establishment of native species, but long-term, continuous management is required to facilitate functional eradication of Phragmites by keeping it at low levels of occurrence and restoring native plant communities. Ultimately, historical data from sites that were sampled as part of this study indicate that if management is successful and results in functional eradication of Phragmites, then the recovering vegetation will include native species that were present before the sites were invaded by Phragmites. [ABSTRACT FROM AUTHOR]

The Indo-Pacific, a vast biogeographic of Earth, is influenced by both the Indian and East Asian monsoons. Despite its geographical importance, this region has been less studied compared to East Asia and India. Here, we present speleothem records from southern Thailand that cover the last 1500 years, including a hiatus during the Little Ice Age, providing insights into the interactions among climate dynamics, human influences, and ecological responses to climate change. Notably, our records lack the characteristic cold and warm periods observed in other regions, such as the Dark Ages Cold Period and Medieval Warm Period, which may reflect the complexity of the tropical climate system or the region's unique topography. The analysis reveals a link between ENSO multi-decadal variability and hydroclimate conditions in southern Thailand, as evidenced by speleothem δ18O. Furthermore, a comparison between speleothem δ13C and the Normalized Difference Vegetation Index (NDVI) indicates significant vegetation changes in the last three decades, corresponding with increased atmospheric CO2 levels and expansion of agricultural land due to human activities during the Current Warm Period. Additionally, our study suggests that an abrupt increase in sea surface temperatures may enhance vegetation growth in the Indo-Pacific by influencing atmospheric circulation and increasing precipitation. [ABSTRACT FROM AUTHOR]

Based on remote sensing images and measurements of soil organic carbon content (including 28 sample sites, 112 soil samples from forests, grasslands, croplands, and construction lands), methods including Sen's trend analysis, Hurst exponent, partial correlation analysis, and the InVEST model were employed to investigate the spatiotemporal variations in vegetation and carbon storage of the mountainous ecosystem in northeastern Guangdong province. The results show that; (1) The research area exhibits relatively high vegetation coverage, with a Normalized Difference Vegetation Index (NDVI) ranging from 0.14 to 0.95 and an average value of 0.79. From 2000 to 2021, the vegetation coverage of the study region increased. Apart from the city area of Meizhou, the rest showed varying degrees of NDVI increase, especially in mountainous areas, where it showed a trend of rising and subsequently declining with elevation. The Hurst exponent (<0.5) implies a potential declining trend in vegetation changes in the study area. (2) From 2000 to 2020, the carbon storage in the study area displayed a decreasing trend, amounting to a total reduction of 1.33 teragrams (Tg). Land use changes, particularly the conversion of forests and grasslands into agricultural and urban areas, are the primary reasons for the decrease in carbon storage in the study area. The conclusions can serve as fundamental data for investigating the changes in carbon sequestration functionality within subtropical ecosystems in China. [ABSTRACT FROM AUTHOR]

The grassland ecosystem in the Inner Mongolia Autonomous Region (IMAR) serves as a vital ecological barrier in northern China, and the vegetation productivity in the grasslands exhibits considerable temporal and spatial variations. However, few studies have examined the long-term variations in the NPP in the IMAR and quantified the effects of natural factors and human activities on the NPP. The study modeled the net primary productivity (NPP) of the IMAR’s grasslands using the Carnegie–Ames–Stanford approach (CASA) model and employed linear regression, trend analysis, and spatial statistics to analyze the spatio-temporal patterns in vegetation productivity and explore the impact on the NPP of natural and socio-economic factors over the past two decades. The results reveal that the average NPP value from 2001 to 2021 was 293.80 gC∙m−2 a−1, characterized by spatial clustering of a relatively high NPP in the east, a low NPP in the west, and an annual increase of 3.26 gC∙m−2 over the years. The NPP values varied significantly across different vegetation cover types, with meadows having the highest NPP, followed by typical steppe and desert grasslands. The spatial distribution pattern and temporal changes in the grassland productivity are the result of both natural factors and human activities, including topographical properties and socio-economic indicators such as gross domestic product, night-time light, and population. The results for the NPP in the IMAR were based solely on the CASA model and, therefore, to achieve improved data reliability, exact measurements in real field conditions will be conducted in the future. The findings from the spatial clustering and temporal trajectories of the NPP and the impacts from the factors can provide useful guidance to planning grassland vegetation protection policies for the IMAR.

Awareness of the types of vegetation changes and human activities in different parts has particular importance as basic information for different planning. It is very difficult and expensive to collect information about the continuous changes in vegetation cover by conventional methods. Therefore, the use of new technologies such as remote sensing is very beneficial. The objective of the present research was to introduce the appropriate vegetation index and determine the vegetation cover of the Abshar network. NDVI, EVI, SAVI, and MSAVI vegetation indices were calculated from 2000 to 2021 every year and monthly in the Google Earth Engine system using Landsat 7 satellite images of the ETM+ sensor. Also, the SPI drought index was calculated using the precipitation statistics of Kohrang station in Excel software. The results of the comparison of four indices showed the superiority and higher performance of NDVI compared to the other three indices for detecting vegetation changes. Then, vegetation changes were calculated. The results showed that the trend of agricultural development in the Abshar network is downward and has a direct relationship with precipitation and the SPI drought index. Also, the results indicated that the SPI drought index was equal to -1.73in 2008, which showed a severe drought in the region. Comparing these results with the vegetation area showed that the vegetation area was 35721 hectares in this year and the year after the drought (2009), the vegetation area was 22950 hectares. Therefore, there was a decrease in precipitation and a sharp decrease in the SPI index in 2008, which led to a sharp decrease of 35% in the vegetation area in 2009.

The Eurasian beaver has a significant impact on biotic and abiotic resources, thus it is known as an “ecosystem engineer”. Currently, the beaver population in Eurasia is estimated at more than 1.4 million individuals due to successful reintroductions in many countries. The recognition of its impact on ecosystems is increasing every year, therefore this article summarizes the current knowledge of how the Eurasian beaver affects the local flora and vegetation in the area where it settles. Beavers initiate a transformation of their closest surroundings with the dams and ponds they create by forming wetlands, and the newly developed vegetation is richer in plant species than previously. Beaver activities lead to a decrease in local woody plant resources and an increase in the species diversity of herbaceous plants. Beavers also cause damage to agricultural crops when they feed on cultivated plants. Observed changes can vary over time and landscape scales due to local conditions and persistence of beaver occurrence. Understanding how beavers affect plants and vegetation may be helpful not only in the protection of the species itself, but also in better management of the areas where they occur.

Copyright of Nativa is the property of Revista Nativa and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Maintaining biodiversity in agricultural landscapes is a major challenge for environmental protection in Europe. Vineyards rely heavily on agrotechnical interventions such as herbicide use and tillage for weed control, which affect biodiversity and can lead to soil erosion and resistant weed populations. The fragmentation of agricultural landscapes affects biodiversity by altering community composition and often reducing plant population sizes and genetic diversity. However, it can also increase the abundance of certain species and enhance population resilience to environmental change. Vineyards can support high levels of biodiversity and provide ecosystem services due to their semi-natural habitat structure. This research evaluates vegetation biodiversity using phytosociological relevés in different vineyards. Our results show that species richness and biodiversity are significantly influenced by vineyard age and management type. This study highlights differences in the representation of plant functional groups, with perennial taxa in grassy inter-row contributing to anti-erosion functions and serving as food sources for pollinators. The root zone around vine trunks shows an increase in invasive species with vineyard age, posing a risk to the agroecosystem. Vineyards predominantly follow a ruderal ecological strategy, using nutrients and light efficiently, while tolerating management disturbances. Understanding these dynamics is critical for developing sustainable vineyard management practices that support biodiversity and ecological resilience, counteract the homogenization of agricultural landscapes, and promote the coexistence of viticulture and species-rich ecosystems.

The paper presents new data and reviews previously obtained results on the late glacial to Holocene history of peatlands in the southern part of the Baikal region under conditions of regional climate changes. To better understand climate signals, we have combined vegetation and geochemical variation data in 4.6 m thick peat deposits in the Vydrino bog located on the Tankhoi piedmont plain south of Lake Baikal. The territory has been swamped since 13.1 cal ka BP when the peatland started developing as a fen upon a sedimentary substrate. The 13.1–9.5 cal kyr climate record included two events of warming separated by an excursion of dry cold climate. Warming continued till 9.0 cal ka BP and eutrophic peat formation occurred in favorable temperature and moisture conditions. Another warming episode between 9.0 and 8.4 cal ka BP ended up with the Holocene climate optimum while the bog became mesotrophic. About 7.3–6.5 cal ka BP, the temperature and moisture inputs were no longer optimal for fir and spruce forests in the Vydrino area, which led to dramatic changes in landscape and vegetation. The wet and warm climate gradually became drier and colder from 6.5 to 2.3 cal ka BP, with a brief warm excursion about 5.5–5.3 cal ka BP. The peat deposition was interrupted in a cold climate from ∼2.3 cal ka BP to ∼0.7 cal ka BP, and the bog became oligotrophic afterwards. The newly obtained data allowed us to compare the paleoclimatic indicators available for the south Baikal region to determine their compatibility and inconsistency. In addition, we provide a general view to the quality of the climate and environmental reconstructions in the Baikal region by comparison of the data on its peatland study. [ABSTRACT FROM AUTHOR]

Awareness of the types of vegetation changes and human activities in different parts has particular importance as basic information for different planning. It is very difficult and expensive to collect information about the continuous changes in vegetation cover by conventional methods. Therefore, the use of new technologies such as remote sensing is very beneficial. The objective of the present research was to introduce the appropriate vegetation index and determine the vegetation cover of the Abshar network. NDVI, EVI, SAVI, and MSAVI vegetation indices were calculated from 2000 to 2021 every year and monthly in the Google Earth Engine system using Landsat 7 satellite images of the ETM+ sensor. Also, the SPI drought index was calculated using the precipitation statistics of Kohrang station in Excel software. The results of the comparison of four indices showed the superiority and higher performance of NDVI compared to the other three indices for detecting vegetation changes. Then, vegetation changes were calculated. The results showed that the trend of agricultural development in the Abshar network is downward and has a direct relationship with precipitation and the SPI drought index. Also, the results indicated that the SPI drought index was equal to -1.73in 2008, which showed a severe drought in the region. Comparing these results with the vegetation area showed that the vegetation area was 35721 hectares in this year and the year after the drought (2009), the vegetation area was 22950 hectares. Therefore, there was a decrease in precipitation and a sharp decrease in the SPI index in 2008, which led to a sharp decrease of 35% in the vegetation area in 2009. [ABSTRACT FROM AUTHOR]

Background and objectives: Livestock grazing significantly influences the structure and dynamics of vegetation in rangelands, prompting the implementation of exclosure operations as a management strategy. Exclosure involves restricting livestock access to rangelands and is recognized as an effective method for rangeland management and improvement. Numerous studies suggest that exclosure operations lead to positive changes in vegetation indicators, including cover structure, production levels, and species diversity. This research aims to investigate changes in vegetation canopy percentage, production rates, and species diversity under exclosure management in the semi-steppe rangelands of Ghalehgharak, Shahrekord. Methodology: Sampling locations were selected within the exclosure site (Ghalegharak) and an adjacent grazed site. Plant cover sampling was conducted using a random-systematic method over multiple years (2016 to 2021). Four parallel transects of 100 meters in length were established at each site, with 40 plots of 2 * 2 square meters placed along the transects. Canopy cover percentage was determined using the theoretical estimation method, while biomass was measured through the cutting and weighing method. Species diversity was assessed using Simpson and Shannon-Wiener indices, and species richness was compared using Margalef and Menhinich indices in the Past software. Range condition was determined using modified four-factor and six-factor methods, and trends were evaluated using scale and comparison methods. Results: Over the five-year study period, the exclosure site exhibited canopy cover percentages ranging from 34.57% to 52.68%, while the grazed site showed variations from 22.15% to 32.76%. Biomass on the exclosure site ranged from 1215 to 1908 kg/ha, whereas the grazed site's production varied from 693 to 1025.6 kg/ha. The rangeland status was determined as moderate for the exclosure site and poor for the grazed site. The trend for the exclosure site was positive, while the grazed site trend was negative. Significant differences were observed between most evaluation indicators for the enclosed and grazed sites, with exclosure enhancing vegetation indices, canopy cover, and biomass. Exclosure significantly increased species diversity and richness, as indicated by Simpson, Shannon-Weiner, Margalef, and Menhinich indices. Conclusion: The research findings indicate that exclosure positively influences vegetation, biomass, and species diversity in rangelands. Given the declining performance of grazing rangelands in recent years, implementing exclosure operations and strategic livestock grazing management emerges as a favorable approach for pasture improvement and altering current trends. [ABSTRACT FROM AUTHOR]

Aim: In the face of ongoing climate warming, we wanted to quantify impacts on vegetation at one of the major climatic and biogeographical boundaries of Europe, the limit between the Mediterranean and Eurosiberian biogeographical regions. We analyse temperature and moisture requirements of plants along altitudinal gradients at regional scale in the period 1980–2020 and we explore if changes coincide with observed changes in the same regions in terms of measured climatic data. Location: Southern France. Time period: 1980–2020. Taxa: Vascular plants. Methods: We calculated shifts in plants' temperature and moisture requirements for a large floristic database from south‐eastern France (SIMETHIS) during the period 1980–2020 along altitudinal gradients by using ecological indicator values (EIV). Additionally, we analysed standardized weather station data from the same area and period, to investigate whether floristic changes are synchronized with climate changes. Results: Vegetation data suggest a linear increase in temperature requirements of plant communities from 1980 to 2020 with a greater change at low altitudes. Upward shifts in temperature requirements coincided with observed climate change although warming did not show a general trend towards greater increases at low altitudes. Data on vegetation and climate suggest an upward shift of respectively 150 and 300 m for the boundary between Mediterranean and temperate belts. Moisture requirements of vegetation indicate an increase of the frequency of dry adapted species at low altitudes but an increase towards higher moisture requirements at high altitudes. Comparing vegetation responses with climate data suggests that responses are faster at low altitudes. Main conclusions: Our analyses show that strong general changes in vegetation are underway and highlight faster responses of vegetation to warming in low altitudes compared to high altitudes and demonstrate the need for reliable data on vegetation and climate changes, especially on water balance. [ABSTRACT FROM AUTHOR]

The article presents the impact of Zn and Pb ore mining and land use on ecohydrological changes in the area of the Biała Przemsza valley in the historical aspect, with particular emphasis on the period 1941–2021. GIS was used to analyse the maps to identify spatial and temporal changes in land use. The following trends could be observed in the spatial development of the Biała Przemsza valley: rapid urbanisation and industrialisation in the 21st century, marked reduction in the surface area of arable land and sands, and dynamics of the increase in the surface area occupied by forests. Notable changes occurred in the plant ecosystems between 1941 and 2021 due to land management. Groundwater level lowering due to mining activity resulted in the change from wet meadows to fresh or dry xerothermic grasslands, while forest cover increased by 4% within the catchment area. The hydrographic network evolved. After the commissioning of the Zn-Pb ore mines Olkusz and Pomorzany in the 1960s and 1970s, a regional depression cone with an area of 400 km2 was formed, while the maximum groundwater inflows to the mines reached 360 m3/min. Changes in the hydrodynamic conditions have resulted in changes in the hydrogeochemical regime of the Triassic aquifer manifested by increased levels of, e.g., SO4 and Cl. Wastewater with lignosulphonate compounds from the paper factory caused periodic degradation of some of the water flowing into the Pomorzany mine. As a result of mining activity, the character of some sections of the Biała Przemsza river changed to an infiltrating one, the quantitative depletion of groundwater resources within the range of the mine drainage cone occurred, river springs disappeared, and the flow in the river decreased. At the same time, mine water was discharged to the tributaries of the Biała Przemsza. A radical reduction in the flow of the Biała Przemsza and its tributaries occurred after the decommissioning of the Zn-Pb ore mines at the turn of 2021 and 2022. [ABSTRACT FROM AUTHOR]

Climate changes and vegetation conditions are key factors affecting the hydrothermal processes of frozen soil in the Qinghai–Tibet Plateau. Due to the complex relationship between climate factors, vegetation conditions and hydrothermal processes, few studies analyze the individual influences of climate changes and vegetation conditions on hydrothermal processes. Compared to changes in climate, it is easier to control other influential factors of vegetation change, especially human activities. Thus, it is necessary to analyze the possible influence of vegetation change on hydrothermal processes in specific climate conditions; this analysis could provide technical support to inform future human activities on frozen soil. This study uses a vertical hydrothermal process model, the SHAW model, based on meteorological and soil observation data from 2020 to 2021, to model the influence of vegetation changes on the soil temperature and moisture simulations at each layer of frozen soil by changing the key input values that represent vegetation conditions from −100% to 100% at 10% intervals. The results show that: (1) the simulated values have a certain credibility since the simulated soil temperature and moisture are basically consistent with the observed values over time; (2) the performance of soil temperature simulations in the deep layer is better than that in the shallow layer, while the performances of both soil temperature and moisture simulations in the warm season are better than those in the cold season; (3) among the LAI, dry biomass and surface albedo, the LAI is the main vegetation factor that affects the soil temperature and moisture simulations of the SHAW model in the frozen soil; (4) both the soil temperature and moisture simulations show declining trends when the LAI decreases by a large extent (larger than 60%) or increases, and show increasing trends when the LAI decreases by a small extent (smaller than 50%); (5) the warm period and the freeze–thaw alternating period are, respectively, the key periods when the soil temperature and moisture are affected by vegetation changes. The results of this study can provide theoretical supports for the prediction of the hydrothermal processes of frozen soil under a changing vegetation environment in the future. [ABSTRACT FROM AUTHOR]

In recent years, wildfires in the western United States have occurred with increasing frequency and scale. Climate change scenarios in California predict prolonged periods of droughts with even greater potential for conditions amenable to wildfires. The Sierra Nevada Mountains provide 70% of water resources in California, yet how wildfires will impact watershed-scale hydrology is highly uncertain. In this work, we assess the impacts of wildfires perturbations on watershed hydrodynamics using a physically based integrated hydrologic model in a high-performance-computing framework. A representative Californian watershed, the Cosumnes River, is used to demonstrate how postwildfire conditions impact the water and energy balance. Results from the high-resolution model show counterintuitive feedbacks that occur following a wildfire and allow us to identify the regions most sensitive to wildfires conditions, as well as the hydrologic processes that are most affected. For example, whereas evapotranspiration generally decreases in the postfire simulations, some regions experience an increase due to changes in surface water run-off patterns in and near burn scars. Postfire conditions also yield greater winter snowpack and subsequently greater summer run-off as well as groundwater storage in the postfire simulations. Comparisons between dry and wet water years show that climate is the main factor controlling the timing at which some hydrologic processes occur (such as snow accumulation) whereas postwildfire changes to other metrics (such as streamflow) show seasonally dependent impacts primarily due to the timing of snowmelt, illustrative of the integrative nature of hydrologic processes across the Sierra Nevada-Central Valley interface.

Madagascar is known for its high erosion rates in the central highlands, yet the role of human disturbance versus natural processes is not well understood and is a topic of ongoing debate. At present the necessary quantitative data to couple vegetation dynamics and sediment fluxes over time in Madagascar is scarce. This study aims to provide more insight in vegetation changes and sediment transfers over the last millennia in the Lake Alaotra region, and specifically on the role of human disturbances and natural processes. Our vegetation reconstruction is based on pollen records from two lake sediment cores, covering the last 2600 years. Sediment accumulation rates were calculated from cores obtained from the floodplains, from wetlands surrounding the lake, and from Lake Alaotra itself. Our data show an early opening in the landscape, between 2050 and 1700 cal a BP, with a transition from a wooded grassland or woodland/grassland mosaic towards open grassland and an increase in charcoal accumulation rates. (Indirect) human impact is suggested as the main driver for these vegetation changes. Floodplain and wetland sediment accumulation rates only increase in the last 1000 years and peak in the last 400 years. This increased accumulation can mainly be linked to the increased anthropogenic pressure (grazing and farming activities) that triggered increased lavaka (gullies) activity. No changes in accumulation rate were observed in Lake Alaotra, indicating that most sediments are buffered in the floodplains and wetlands. Overall, our pollen and charcoal data suggest an indirect effect of human disturbance on vegetation shifts whilst strong evidence was found for a direct effect of human disturbance on sediment accumulation through intensified use of the grasslands. [ABSTRACT FROM AUTHOR]

Windstorms are rare in the Southern Alps, but their frequency is increasing due to climate change. This research analyzed the vegetation of two spruce forests in Camonica Valley (Northern Italy) destroyed by the Vaia storm to evaluate the vegetation responses to blowdown damage. In each study area, the normalized difference vegetation index (NDVI) was used to evaluate the change in plant cover and greenness from 2018 (before the Vaia storm) to 2021. Furthermore, floristic-vegetation data were analyzed to identify current plant communities and develop models of plant succession. The results showed that the two areas, although located in different altitudinal vegetation belts, are undergoing the same ecological processes. NDVI is increasing in both areas, and pre-disturbance values (~0.8) should be reached in less than ten years. Nevertheless, the spontaneous restoration of pre-disturbance forest communities (Calamagrostio arundinaceae-Piceetum) should not occur in both study areas. In fact, the two plant succession trends are characterized by pioneer and intermediate stages with young trees of Quercus petraea and Abies alba, typical of more thermophilic mature forest communities compared to pre-disturbance ones. These results could reinforce the trend of the upward shift in forest plant species and plant communities in response to environmental changes in mountain areas. [ABSTRACT FROM AUTHOR]

The current study deals with the monitoring and evaluation of soil moisture and vegetation changes using remote sensing technique and its relationship with the standardized precipitation-evapotranspiration index in Bandar-Dij and Kol-Mehran watersheds in Hormozgan province. For this purpose, soil moisture data at a depth of 0-10 cm was calculated from GLDAS satellite images and standardized soil moisture drought index (SMDI) and standardized normalized difference vegetation index (SNDVI) were used to calculate changes in vegetation cover. The results of the correlation between SPEI and Standardized Moisture Drought Index (SMDI) showed that in all sub-basins, the correlation coefficients increase with the increase of the time scale, and the highest correlation is related to the Minab sub-basin (R=0.764) in the 12-month time scale. Examining the characteristics of drought (severity-duration and magnitude) showed that SPEI showed more intensities in shorter periods of time than SMDI, so it shows more magnitudes of drought. The investigation of the standardized vegetation cover index showed that in most of the sub-basins, since 2012, the decreasing trend of vegetation cover is evident. Investigating the relationship between SPEI and SMDI and SNDVI showed that SNDVI has a high correlation with SPEI and SMDI in a long-term time scale. A comparison of historical droughts between the three indices showed that, although all three indices often showed drought conditions, SPEI always showed extreme conditions compared to changes in soil moisture and vegetation, indicating a delayed response to changes in soil moisture. and vegetation to meteorological drought.

The Mongolian Plateau is an arid and semi-arid region with grassland as its main vegetation. It has a fragile ecosystem and is a sensitive area for global warming. The study is based on MODIS NDVI data and growth season meteorological data from 2000 to 2018, this study examined the spatial and temporal variation characteristics of grassland vegetation on the Mongolian Plateau during the growing season using trend analysis, partial correlation analysis, and residual analysis, and it explores the dual response of NDVI changes to climate and human activities. The study’s findings demonstrated that the growing season average NDVI of grassland vegetation on the plateau gradually increased from southwest to northeast during the growing season; the growing season average NDVI demonstrated a significant overall increase of 0.023/10a (p < 0.05) from 2000 to 2018, with an increase rate of 0.030/10a in Inner Mongolia and 0.019/10a in Mongolia; the area showing a significant increase in NDVI during the growing season accounted for 91.36% of the entire study area. In Mongolian Plateau grasslands during the growing season of 2000–2018, precipitation and downward surface shortwave radiation grew significantly at rates of 34.83mm/10a and 0.57 W/m2/10a, respectively, while average air temperature decreased slightly at a rate of −0.018°C/10a. Changes in meteorological factors of grassland vegetation varied by region as well, with Inner Mongolia seeing higher rates of precipitation, lower rates of average air temperature, and lower rates of downward surface shortwave radiation than Mongolia. On the Mongolian Plateau, the NDVI of grassland vegetation in the growing season showed a significant positive correlation with precipitation (0.31) and a significant negative correlation with average air temperature (−0.09) and downward surface shortwave radiation (−0.19), indicating that increased in NDVI was driven by an increase in precipitation paired with a decrease in air temperature and a decrease in surface shortwave radiation. The overall increase in NDVI caused by human activity in the grasslands of the Mongolian Plateau was primarily positive, with around 18.37% of the region being beneficial. Climate change and human activity both affect NDVI variations in Mongolian Plateau grasslands, which are spatially heterogeneous. Moderate ecological engineering and agricultural production activities are crucial for vegetation recovery. This work is crucial to further understanding surface–atmosphere interactions in arid and semi-arid regions in the context of global climate change.

Recent changes in fen vegetation have been studied in many countries but just a few studies have been carried out in eastern Europe. I re-surveyed four extremely rich fens in Natura 2000 areas in Latvia in 2020 where 23 sample plots were established in 2003 in Schoenus ferrugineus dominated plant communities belonging to Caricion davallianae. Cover of five species and three parameters known to be positive or negative indicators for fen conservation status was estimated to reduce the time and expenses of the study in 2003. The same species and parameters were studied in 2020. The expansion of Molinia caerulea was observed in all sites. In sites hosting Myrica gale, its cover remarkably increased. Concurrently, the cover of target species S. ferrugineus increased in two sites but decreased in one site. In another site, its cover decreased close to the fen margin but increased in the fen expanse. To conclude, succession leads to the dominance of expansive species in all sites. The increase of S. ferrugineus cover in two sites cannot be seen as a positive trend either as the area of vegetation-free patches decreases. Consequently, the habitat niches for fen specialist species that are less competitive, e.g. Primula farinosa, Pinguicula vulgaris, decrease. I assume that the vegetation changes were caused by the combined long-term effects of drainage and abandonment. [ABSTRACT FROM AUTHOR]

Although there is a long history of palaeoecological investigation in the Massif Central, detailed reconstruction of the flora, vegetation, and environment in the Late Pleniglacial, the Würmian (Weichselian) Late-Glacial, and early Holocene in the Monts du Forez (Massif Central, France) is still largely lacking. We inferred the palaeoecology of the area from pollen, spores, and plant macrofossils preserved in the sediments of the palaeolake Gourds des Aillères (1335 m a.s.l.). The lake formed in a glacial depression left by retreating glaciers at the start of the Bølling period, ca. 14700 cal yr BP. Sediment chronology is based on radiocarbon dating and correlation with other, radiocarbon-dated palynological records from the Monts du Forez. Changes in the regional and local vegetation during the Late-Glacial and early Holocene could be correlated to the major climatic events identified in the Greenland oxygen isotope records. We made a highly detailed reconstruction of the changes in the floral diversity and vegetation in and around the lake. After the steppe-tundra of the Late Pleniglacial, local vegetation cover increased and developed into shrub tundra with a few trees forming the tree line in the Bølling and Allerød, with a short reversion during the Older Dryas. During the Younger Dryas trees were eliminated around the site and vegetation was reduced in diversity and density. In the early Holocene, birch (Betula) woodland with some pine (Pinus) developed and was then replaced by mixed oak woodlands with Corylus. The forest limit rose above the lake. Changes in the lake ecosystem, lake-levels, and nutrient availability were also reconstructed. Hydroseral overgrowth of the lake to a Sphagnum peatbog took >6000 years. [ABSTRACT FROM AUTHOR]

Access to basic and up-to-date information on rangeland ecosystems; needs continuous and long-term vegetation measurement. For this purpose, during the years 2018-2021 at a specific time, from the vegetation of plant types representing the saline habitats of Lake Urmia, including; Salicornia europaea, Halocnemum strobilaceum, Aeluropus littoralis-Aeluropus lagopoides-Salicornia europaea, Aeluropus littoralis-Aeluropus lagopoides and Atriplex verrucifera were recorded in the customary system of Osalo. In each of the plant types, considering the dimensions and space between the plant spots, four 300-meter transects with the same azimuth were used, along the salinity gradient, at a distance of 25-50 meters from each other. On each transect, 10 plots were placed at a distance of 30 meters from each other. The plotting was done in such a way that while the distances of the plots were the same, the principle of randomness was observed. Therefore, the starting points of different transects were not the same. Size of sampling units and their dimensions; due to the different distribution of vegetation, the plant types were not considered the same. Plot size for plant types Salicornia europaea, Halocnemum strobilaceum, Aeluropus littoralis-Aeluropus lagopoides-Salicornia europaea, Aeluropus littoralis-Aeluropus lagopoides and Atriplex verrucifera, respectively; 0.5, 2, 0.5, 0.25 and 2 square meters were considered. Average forage production of the study site during 1397, 1398, 1399 and 1400, respectively; 404.6, 456.6, 478.6 and 338.2 kg/ha and the average percentage of canopy cover were 48.4, 54.6, 58.8 and 41.1%. During this period, the average annual rainfall had a downward trend and compared to the long-term average (346.9 mm) in the years 2018-2021, respectively; intense wetness; medium wet; the normal year was moderate in terms of rainfall and drought in the region. Overall, no direct relationship was observed between the amount of production and the rainfall of the region and the meteorological drought situation. Therefore, ecological behavior in such habitats seems to be similar to wetland ecosystems, and depending on this behavior, it is expected that the amount of ecosystem performance is more affected by surface water and the amount of floods entering the lake. Average range condition of plant types; in total, the years were different from each other, but no significant difference was observed between the scores obtained in different years, despite a 15% change in the mean score. The mean score of plant types in all years was 38.7, 35.1, 46.5, 0.49 and 39.3 which had the highest value related to plant type Aeluropus littoralis-Aeluropus lagopoides and the lowest value related to plant type Halocnemum strobilaceum is. The average score of rangeland determinants in each of the years 1397, 1398, 1399 and 1400, respectively; 39.3, 43.0, 45.8 and 38.7. Thus, in order to properly understand changes in range condition, it is necessary to have information about certain time periods (for example, once every five years). [ABSTRACT FROM AUTHOR]

Transgressive sand sheets (TSS) and transgressive dunefields (TDf) over time often present multiple phases of development and various morphologies controlled by biogeomorphological interactions related to abiotic processes, vegetation, and human interference. While dunefields have experienced increased vegetation cover over the last decades worldwide, a few places have shown increased dune mobility. In this study, a GIS analysis was conducted using aerial photographs and satellite imagery to investigate the evolution of a TDf, foredune collapse, new TSS formation, and vegetation cover on a Holocene coastal barrier in southern Brazil over the last 75 years (from 1948 to 2023). Wind speed (1994–2009), significant wave height (Hs) and peak wave period (Tp) (1940–2022) were analyzed to examine these potential drivers that could have caused geomorphological changes on the foredunes and dune system. Vegetation cover exhibited an increasing trend, and both an increase and decrease in TDf movement and TSS expansion were concurrent. Correlation analyses revealed a strong negative correlation between vegetation cover and TDf movement. Three transgressive sand sheet formation phases were identified between 1948 and 2023 (1964 to 1975,1996 to 2000, and from 2010 until 2023). Post-2003, a poorly vegetated nebkha-dominated foredune subsequently collapsed and was replaced by a TSS in less than a decade, being fully formed in 2010 and continuing to move inland at rapid rates. In the third phase, the highest total TSS expansion exceeded 700 m in 12 years (from 2010 to 2022). A small increase in wind velocity and subsequent decrease may possibly have contributed to the formation of the TSS second phase and the foredunes respectively. Other possible drivers for TSS formation include climatic modes, negative precipitation anomalies and groundwater level lowering, in addition to anthropogenic actions (especially water extraction) that might have caused a negative feedback in foredune sand-biding vegetation. • Aeolian system at Praia dos Concheiros has undergone significant changes in geomorphology and vegetation over 75 years. • Vegetation has shown a strong increasing trend, as observed in other regions of Brazil and the world. • A poorly vegetated nebkha-dominated foredune collapsed and was replaced by a TSS in less than a decade. • TSS inland movement exceeded 700 m in 12 years (from 2010 to 2022). [ABSTRACT FROM AUTHOR]

Purpose. To study ecological regularities of the formation of vegetation cover in Ukraine depending on the climatic conditions and analyze its possible changes due to global warming. Methodology. The research methodology involves the following: diff erentiation of the climatic conditions and evaluation of the signifi cance of climatic indices at the level of territorial units of a geobotanical zoning based on variance analysis; multiple ordering of the geographic locations in terms of climatic indices basing on the analysis of main components (Principle Component Analysis); development of a typological scheme of the vegetation cover relying upon a discriminant analysis; statistic processing of the climatic parameters. Findings. Modelling of spatial diff erentiation of climatic indices depending on the location latitude and longitude as well as altitude above the sea level helped analyze the connection of vegetation cover and climate. It has been determined that peculiarities of the vegetation cover formation according to a scheme of geobotanical zoning is characterized in the most accurate way by the diff erence of such climatic indices as: air temperature in January, July, and August; monthly precipitation amounts during JuneSeptember; duration of a frost-free period; and hydrothermal coeffi cient of T.G. Selianinov. The main regularity of the formation of Ukrainian vegetation cover has been defi ned. The regularity means the following structure of interrelation between the climatic indices: along with the growing average monthly temperatures of June-September and decreasing precipitation amounts from April to September, the indices of climatic water availability decrease along with the increasing heat availability indices (duration of an active vegetation period and total of temperatures per that period, average annual temperature). This regularity represents a gradient of climatic indices from the Ukrainian Carpathians towards the southern Crimean coast. It has been determined that during some years of the early 21st century, the conditions peculiar for a steppe area were formed for the forest and forest steppe areas. Originality. The vegetation cover of Ukraine is characterized by the ecological range, which is evaluated basing on ordering of the geographical locations in terms of coverage of complex climatic environmental gradients. A typological scheme of the Ukrainian vegetation cover can be represented in a two-dimensional space in the form of square parabola, whose left branch shows a gradient of climatic factors and changes in vegetation cover from the west to the north-east and right branch indicates it from the north-east to the south. Graphic visualization of climatic information on the basis of ecograms and typological schemes of vegetation cover can be used to predict the vegetation cover dynamics due to certain climatic changes. Practical value. While understanding the climatic conditions of geographic locations during certain periods of time, one can identify their location in the ecological and coenotic range of Ukrainian vegetation and predict their stability and possible changes in the vegetation cover due to global warming. [ABSTRACT FROM AUTHOR]

The face of the earth is always changing due to human activities and natural phenomena. Therefore, to optimize the management of the natural areas, knowledge of the trend, extent and estimation of land cover / use changes is considered necessary. Reviewing these changes through satellite images and evaluating their potential through modeling can help environmental planners and natural resource managers to make more informed decisions. In the present study, quantitative detection and evaluation of changes in vegetation were performed in the areas with combat desertification projects, Shahdad, Bam and Garmsar in Iran, during a 30-year period within 1987, 2002 and 2017. The Normalized Difference Vegetation Index (NDVI) and land use maps were produced using the Enhanced Thematic Mapper Plus (ETM+), Thematic Mapper (TM) and Operational Land Imager (OLI) satellite images in the three corresponding periods for the vegetation/non-vegetation, and agricultural lands. The Kappa coefficient of 0.83 to 0.86, 0.91 to 0.92, and 0.94 to 0.95 was calculated for 1987, 2002, and 2017 respectively, and the total accuracy was between 88 and 97. After providing the land use maps in different years, the monitoring of land use changes was investigated using the Change Detection method. According to the trend of changes during the periods, the results exhibited that the vegetated lands in these three areas had an increasing trend in average 31.33%, and the non-vegetated lands were turned to vegetated lands over time. In other words, they have declined by an average of 35%. Moreover, an increasing trend was found for the agricultural lands during the periods in average 4%. Eventually, the cost-effectiveness of projects implemented in the studied areas was calculated.

Inner Mongolia grassland is a sensitive area of vegetation response to climate change in China and an ecologically fragile area of terrestrial ecosystem, which is easily degraded due to the coordinated interference of natural and human factors. Therefore, it is of great practical significance to explore the spatial-temporal variation of vegetation coverage and the influence of hydrothermal conditions on its growth, to protect the regional ecological environment, to realize the sustainable development of animal husbandry and to make more reasonable and effective use of grassland resources in Inner Mongolia. In this study, linear regression, partial correlation analysis and Copula method were used to investigate the spatial patterns of NDVI internal variability and its relationship with climate change in various regions of Inner Mongolia from 1982 to 2020, and the results are as follows:(1) From 1982–2020, the surface vegetation coverage in Inner Mongolia showed an increasing trend, and the main climatic factors affecting vegetation growth in Inner Mongolia were different. In the eastern and central parts of the study area, vegetation growth is highly dependent on precipitation, while in the western part of the study area, vegetation growth is greatly affected by climate and precipitation. (2) When the temperature and precipitation of vegetation growth exceed a certain threshold, the probability of plant growth inhibition is higher. (3) NDVI variation trends of different vegetation types are also different. The meadow vegetation degraded obviously, while the marsh vegetation and desert vegetation increased obviously. (4) In addition to climate influences such as temperature and rainfall, livestock numbers and human population are the main forms of human activities accelerating grassland degradation. The results of this study can help us understand the appropriate range or types of environmental factors affecting vegetation growth in Inner Mongolia, and on this basis, we can take appropriate interventions to effectively mitigate the impact of environmental change on vegetation.

Climate change is causing severe changes in the ecosystem, thus understanding how plants respond to drought is essential to protecting ecosystems in Inner Mongolia. Multi-temporal variations of drought in Inner Mongolia were studied using the Standardized Precipitation Evapotranspiration Index (SPEI), and the vegetation growth was analyzed using the Normalized Difference Vegetation Index (NDVI). Moreover, the correlation between droughts of different lengths and NDVI was studied. Subsequently, we developed an optimal binary probability model to calculate the probability of vegetation productivity loss at different drought levels using the copula method. The results showed: (1) a weak aridification in the western parts and significant wetness in the central and eastern parts of Inner Mongolia; (2) a significant decreasing trend of NDVI from 1982 to 2009 and a significant increasing trend from 2010 to 2015; (3) a strong positive correlation between NDVI and SPEI and a difference between their related time scales based on soil textures; and (4) a higher probability of vegetation productivity loss with increasing drought at different drought levels.

The article presents the impact of Zn and Pb ore mining and land use on ecohydrological changes in the area of the Biała Przemsza valley in the historical aspect, with particular emphasis on the period 1941–2021. GIS was used to analyse the maps to identify spatial and temporal changes in land use. The following trends could be observed in the spatial development of the Biała Przemsza valley: rapid urbanisation and industrialisation in the 21st century, marked reduction in the surface area of arable land and sands, and dynamics of the increase in the surface area occupied by forests. Notable changes occurred in the plant ecosystems between 1941 and 2021 due to land management. Groundwater level lowering due to mining activity resulted in the change from wet meadows to fresh or dry xerothermic grasslands, while forest cover increased by 4% within the catchment area. The hydrographic network evolved. After the commissioning of the Zn-Pb ore mines Olkusz and Pomorzany in the 1960s and 1970s, a regional depression cone with an area of 400 km2 was formed, while the maximum groundwater inflows to the mines reached 360 m3/min. Changes in the hydrodynamic conditions have resulted in changes in the hydrogeochemical regime of the Triassic aquifer manifested by increased levels of, e.g., SO4 and Cl. Wastewater with lignosulphonate compounds from the paper factory caused periodic degradation of some of the water flowing into the Pomorzany mine. As a result of mining activity, the character of some sections of the Biała Przemsza river changed to an infiltrating one, the quantitative depletion of groundwater resources within the range of the mine drainage cone occurred, river springs disappeared, and the flow in the river decreased. At the same time, mine water was discharged to the tributaries of the Biała Przemsza. A radical reduction in the flow of the Biała Przemsza and its tributaries occurred after the decommissioning of the Zn-Pb ore mines at the turn of 2021 and 2022.

Windstorms are rare in the Southern Alps, but their frequency is increasing due to climate change. This research analyzed the vegetation of two spruce forests in Camonica Valley (Northern Italy) destroyed by the Vaia storm to evaluate the vegetation responses to blowdown damage. In each study area, the normalized difference vegetation index (NDVI) was used to evaluate the change in plant cover and greenness from 2018 (before the Vaia storm) to 2021. Furthermore, floristic-vegetation data were analyzed to identify current plant communities and develop models of plant succession. The results showed that the two areas, although located in different altitudinal vegetation belts, are undergoing the same ecological processes. NDVI is increasing in both areas, and pre-disturbance values (~0.8) should be reached in less than ten years. Nevertheless, the spontaneous restoration of pre-disturbance forest communities (Calamagrostio arundinaceae-Piceetum) should not occur in both study areas. In fact, the two plant succession trends are characterized by pioneer and intermediate stages with young trees of Quercus petraea and Abies alba, typical of more thermophilic mature forest communities compared to pre-disturbance ones. These results could reinforce the trend of the upward shift in forest plant species and plant communities in response to environmental changes in mountain areas.

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Invasive alien species (IAS) have a severe impact on indigenous vegetation globally, including in riparian ecosystems, which are already subject to severe natural and anthropogenic modifications. This paper presents a case study of the long-term impact of IAS that was carried out on the banks of the Tiber River near Lake Alviano in Central Italy. We compared the vegetation composition from 1998 and 2020, to record IAS invasion after a time-lapse of 22 years. We performed 48 phytosociological relevés in 2020, using the same method that had been used in 1998 (with 46 relevés). The importance of IAS in determining the changes in floristic composition and vegetation dynamics was quantified using chorology, life forms and Ellenberg's ecological indicator values. Results of our multivariate analysis revealed that Paspalum distichum L. and Amorpha fruticosa L. are the most impactful species, due to their ecological traits that make them highly competitive in disturbed environments. Ellenberg's indicator values show that the habitat has shifted towards increased eutrophication and warming. The multivariate analysis confirmed a change in species composition and therefore in vegetation, leading to a more monotonous habitat with completely different vegetation types than before. Finally, the consequences for Natura 2000 habitats were assessed. Key policy insights IAS drastically changed and reduced the cover of native vegetation species between 1998 and 2020, changing the environment from an herbaceous marshy vegetation type to a more homogeneous shrubland. The analysed habitat increased in eutrophication driven by 22 years of overgrazing and by the establishment of a nitrogen-fixing IAS (Amorpha fruticosa L.). The most impactful IAS were Paspalum distichum L. and Amorpha fruticosa L. Some IAS (e.g. Paspalum distichum L.) are currently considered characteristic species of some N2000 habitats (e.g. 3280 and 3290), presenting a paradox of the negative effects of invasions and evidencing a gap in the inclusion of important native communities in the EU Habitats Directive worthy and in need of protection. [ABSTRACT FROM AUTHOR]

The diversity and structure of plant communities are valuable indicators for assessing landscape quality. Land-use change is one of the main factors considered to affect and have the strongest impacts on biodiversity. In this study, we assessed the effects of the conversion of tropical dry forests and savannahs into agricultural lands on the floral diversity and the structure of the vegetation. For this purpose, we carried out vegetation surveys in 198 plots of 50 m × 50 m. Within each plot, we documented all herbaceous, shrubby, and tree species present. We calculated total, spatial, and local floral diversities by land-use types and characterized the structure of the plant communities. Our results show that the overall floral diversity of the study area remains quite high (483 species of vascular plants from 298 genera and 71 families) and was not strongly impacted by agricultural land use (Pareto inequality index is 23–77). Croplands had the highest spatial (9.4) and local diversities. There was no significant difference between the land-use types in terms of the native species richness while croplands harbored significantly the most alien species. Agricultural land use significantly affected the structure of the plant communities. Trees are very rare in croplands and are frequent in forests and savannahs. The clearing of Guinean dry forests and savannahs for cropping did not automatically lead to a loss of some aspects of ordinary floral diversity. For a better understanding of the effects of land-use change on biodiversity, it would then be more suitable to specify in the studies whether the species concerned are native, alien, generalist, or specialist.

Soil and changes in vegetation may affect ant assemblages, but the relative importance of each in different habitats is not well characterized. In particular, information on the effects of ecological restoration on arthropods is scarce. It was decided, therefore, to study how reforestation may affect an ant assemblage. Ants were sampled in area that had been reforested and adjacent grassland using pitfall traps. Soil surface and vegetation were characterized. The disturbance of the vegetation caused by reforestation resulted in a decrease in the cover of Stipa tenacissima and Cistaceae and an increase in the cover of pine. The mechanical preparation of the site also resulted in changes in the soil surface, with an increase in the cover of stones and rocks. Ant species richness and abundance were greater at the reforested site than in the grassland and more species showed a positive than a negative response to reforestation. The underlying causes of this pattern are mainly related to changes in vegetation and structure of the soil surface and are associated with the increase in the cover of pine, which most probably provided additional food resources, and the greater cover of stones and rocks that provided more shelter for the ant assemblage.

Climate change and extreme drought and heat events impact the Mediterranean evergreen sclerophyllous vegetation in South Europe, especially in Iberian and Italian peninsula, where widespread crown defoliation and dieback have been observed since the 90s of the XX century. Field observations and long-term experiments showed different sensitivity of the various woody species, Quercus ilex and Arbutus unedo being prone to drought, whereas Phillyrea latifolia and Pistacia lentiscus appeared to be resistant. The present review aims at exploring the phylogenetic and evolutionary basis of the resistance (or susceptibility) to drought of Mediterranean vegetation and its possible mechanisms of resilience. The main findings are summarized as follows: (1) Mediterranean regions in the world are refuge areas for several plant evolutive lineages and migratory routes. Evergreen sclerophyllous species, currently presented in Mediterranean basin, evolved under different climatic conditions; (2) the evergreen habitus represents an adaptation to mild drought conditions. Deciduous (specially summer deciduous) species are better performing under severe drought and low air relative humidity than evergreen species; (3) severe drought events acts selectively by favouring the species evolved in the Quaternary era and those originated in drier regions; (4) the evergreen trees and shrubs are resilient to the severe drought events and can restore the pre-event condition by resprouting from dormant buds in the cambium tissue. This ability is related to the non-structural carbohydrate content in the parenchyma-rays in woody stems. The amount and availability of these strategic reserve can be compromised by frequent drought events; (5) plant seed regeneration can be affected by drought and seedling establishment may be limited by soil dryness and microenvironment conditions; (6) the role of phenotypic plasticity of the species and epigenetic responses in Mediterranean-type ecosystems, although discussed in few papers, is still poorly known. We hypothesize that instead of latitudinal (South to North) or altitudinal (lowland to upland) plant migrations, Mediterranean forest ecosystems may respond to climate change by modulating their species composition and community structure with genetic resources (i.e., taxonomic diversity) already present in loco. Changes in vegetation assemblages and community structure may lead changes in ecological and landscape ecosystem values, with changes in related ecosystem services. A redefinition of management criteria of natural resources and a pro-active silviculture to make forest ecosystems more resilient are required. [ABSTRACT FROM AUTHOR]

Objective: to evaluate the changes in land use that occurred in Pine and mixed forests, at the national level during the period 2001 to 2013. Design/Methodology/Approach: layers of Land Use and Vegetation (Sp. equ. USV) of Series II (from 2001) and V (from 2013) of the Instituto Nacional de Estadística y Geografía, scale 1: 250,000 were used. Different categories of vegetation under study were reclassified and homogenized for both covers. Rates of change and indicators of transitions were estimated for the spatial-temporary analysis: surfaces of estimated losses and gains, indices of persistence, exchanges and net changes; also, indices of gain and loss to persistence. Results: the rate of negative change for primary forests (Pine and mixed) ranges from 0.80 to 1.84. It was observed that 120 047 km² (57.72%) were stable surfaces. However, 36 986 km² (18.00%) were losses, 14 369 km² gains and 28 738 km² (14.00%) between categories. It was observed from 2001 to 2013 that 13.69% of the area corresponding to primary forests which existed in 2001 became part of secondary vegetation in 2013. Study limitations/Implications: in order to observe the influence of other categories, it would be important to incorporate more classes throughout the study to be analyzed globally in the system throughout the country. Findings/Conclusions: The persistence of the coverage of primary forests is important to design conservation policies. [ABSTRACT FROM AUTHOR]

• A system for vegetation change mechanisms in cold-arid mountainous was developed. • Climate factors dominate vegetation greening and exist nonlinear thresholds. • Topographic factors coupled with multi-factors influence vegetation degradation. • Reasonable sustainable planning can avoid further degradation of vegetation. Understanding vegetation evolution trends and their driving mechanisms are essential to uncover changes in ecosystem structure and function. Under the interaction of natural and human factors in cold-arid mountainous region, the main controlling factors and degree of nonlinear influence are not yet clear. This study utilized trend analysis, along with modeling techniques such as boosted regression trees (BRT) and structural equation model (SEM), to identify and quantify the contributions and nonlinear response thresholds of natural and human factors to normalized difference vegetation index (NDVI) in the Qilian Mountains from 2000 to 2020. The results showed that the implementation of ecological projects made the overall vegetation into greening trend (91.06%), while irrational human activities led to degradation in the central-eastern regions. The BRT showed that climatic factors dominated for overall vegetation changes, greening and significant greening. Thresholds exist for different drivers to influence both greening and degradation of vegetation. Regarding degradation/significant vegetation degradation, the importance of climate factors decreased, and topography ranked first, followed by population density and LUCC. The expansion of building and unused land will inhibit vegetation greening. SEM revealed that climate factors continued to maintain positive effect with the warm-humid change. The destruction of forestlands and grasslands led to significant degradation of vegetation in the central-eastern regions with the largest total negative effect. Topographic factors coupled with multi-factors inhibited vegetation growth in the central-eastern regions. This study provided a new framework for accurately assessing the dynamic evolution of vegetation, and better reveal the multi-factor driving mechanism vegetation changes in cold-arid mountainous regions. Future research should consider combining more accurate AI algorithms with field surveys to quantify the coupling mechanisms between factors and vegetation dynamic. It is expected to provide scientific guidance for vegetation ecosystem planning in other mountainous regions globally and support the achievement of sustainable development. [ABSTRACT FROM AUTHOR]

Karelia, like the entire Fennoscandian Shield, is a region with a low seismic activity. An example of the best-studied locality is a paleoseismic dislocation on Mount Vottovaara, which bears traces of disastrous Holocene geological events following the degradation of the last ice sheet. The evolution of the study area falls into three stages. At pre-Quaternary stage I, an uplifted block broken by numerous fractures and faults was formed. At glacial stage II, coarse clastic moraine was formed, the moving ice polished the crystalline basement surface and glacial scars were formed. At final deglaciation stages, the mountain top remained a nunatak. As Salpausselkä II marginal sediments retreated by about 70 km from the mountain, a postglacial stage in the region's evolution, at which an earthquake occurred, began. It could have been triggered mainly by the consequences of the degradation of the Late Weischelian glaciations such as the rapid removal of the glacial load that contributed to the rejuvenation of various old faults. Changes in paleoecological conditions for the Mount Vottovaara area were reconstructed based on the results of lithological, palynological, diatom and radiocarbon studies of bottom sediments from a small lake on the mountain top. Vegetation dynamics from the Younger Dryas to the Subboreal period is presented. Small lake evolution stages were distinguished based on analysis of diatom complexes and the pollen and spores of aquatic and aquatic-subaquatic plants and Pediastrum algae. The data obtained show that minerogenic sediments were abruptly succeeded by organic in the late Preboreal-early Boreal period. The thickness of Boreal sediments and changes in the composition of diatom complexes and spore-and-pollen spectra suggest a depositional hiatus triggered by a strong earthquake which changed the water level of the pond and its basin structure. The earthquake is also indicated by numerous dismembered, displaced, thrown-away and shifted rock blocks and seismogravity downfalls. Deflation and other types of weathering are responsible for the formation of seide-shaped piles of blocks and boulders on the mountain top. [ABSTRACT FROM AUTHOR]

In order to reveal the changes of vegetation in southern China since the Last Glacial Maximum, we have established high-resolution time scales and palynological sequences of borehole profiles by drilling cores in some weak areas of the research to restore vegetation changes over the past 20,000 years on the basis of previous work. This paper gives the vegetation zoning maps of 18, 9 and 6 ka BP respectively in southern China, and describes the distribution characteristics of plants in different zones/subzones. The results show that the vegetation zonations around 18 ka BP were significantly different from that at present. It appeared in turn with Cold-temperate coniferous forest and alpine meadow steppe zone, and Temperate mixed coniferous and broad-leaved forest zone/warm temperate deciduous broad-leaved forest zone from northwest to southeast in the west, and Temperate mixed coniferous and broad-leaved forest zone, Warm temperate deciduous broad-leaved forest zone, and Northern subtropical mixed evergreen and deciduous broad-leaved forest zone from north to south in the central and east. The vegetation distribution around 9 ka BP changed distinctively. Except that the northwest part was located in Mountain temperate mixed coniferous and broad-leaved forest zone, the vegetation in other areas occurred in turn with North subtropical mixed evergreen and deciduous broad-leaved forest subzone, Mid-subtropical typical evergreen broad-leaved forest subzone, and South sub-tropical monsoon evergreen broad-leaved forest subzone/Tropical seasonal rainforest and rainforest zone from north to south. There was little change in the appearance of vegetation zonations between 6 and 9 ka BP, but the northern edge of each vegetation belt moved a little northward, reflecting that the overall climate became warmer around 6 ka BP. The vegetation changes in southern China over the past 20,000 years were largely driven by environmental changes. Climate change was the main factor affecting the vegetation distribution. The impact of human activities became more and more remarkable in the later period. In the lower reaches of the Yangtze River and the delta region, sea level changes also influenced the vegetation distribution. [ABSTRACT FROM AUTHOR]

• NDVI trends and relations with climate are explored in the Yarlung Zangbo River Basin. • Gridded high-resolution data enable exploring spatial variations of NDVI in detail. • 16.8% of the area had rising trends in NDVI with the strongest in the Nyang subbasin. • NDVI variations were largest across middle ranges of elevation and climate gradients. • Relationships between vegetation growth and climate varied markedly with aridity. Changes in vegetation growth may influence the availability of water resources. Located on the Tibetan Plateau, the Yarlung Zangbo River Basin (YZRB) is a major freshwater source for Tibet, China and downstream South Asian countries, with high spatial heterogeneity in altitude and climate from the upstream to downstream regions. In this study, we combined satellite-based gridded datasets of the normalized difference vegetation index (NDVI), topography, precipitation, and temperature to investigate how vegetation growth has changed in the YZRB over recent decades (1982–2010), and to determine their driving mechanisms. Although a statistically significant trend in growing season NDVI was not detected at the basin scale, at the pixel scale 16.8% and 5.3% of the area of the YZRB was found to exhibit increasing and decreasing trends, respectively. The greatest increases occurred in the Nyang subbasin. Variations of NDVI values along elevation, precipitation, and temperature gradients revealed the greatest variation over the middle ranges of the three variables. Partial correlation analyses indicate that in both arid and semi-arid regions of the YZRB precipitation is positively correlated with NDVI. The relationship between NDVI and temperature varies with aridity, reflecting different effects of snow-melting processes on vegetation growth. Temperature positively correlates with NDVI in the arid region. In addition, a negative correlation between NDVI and temperature is detected in the semi-arid region. This is the first comprehensive study to explore climate–vegetation–hydrology relationships in the YZRB at a spatial resolution finer than those derived from sparse in-situ meteorological stations or low resolution global climate datasets. Our results are valuable for understanding ecohydrological processes in both arid and semi-arid regions of this internationally important river basin. [ABSTRACT FROM AUTHOR]

Abstract This study explores the long-term drivers of changes in lake mixing regime and the causes of lacustrine anoxia in the 2000 year-long, varved sediment record from Lake Żabińskie in northeastern Poland. Annually resolved geochemical data (μXRF and CNS) and pollen data were used to find links between changes in catchment land use and lake mixing regime. Furthermore, we tested the applicability of the Fe/Mn ratio for the reconstruction of past water ventilation. Multivariate statistical analyses show that Fe and Mn were mostly independent of terrestrial inputs and lake trophy, meaning that the Fe/Mn ratio mainly responded to changes in redox potential in hypolimnetic waters. Characteristic changes of the Fe/Mn ratio corresponded to transformations of woodland cover in the catchment as registered by changes of the arboreal/non-arboreal pollen ratio. Six main phases of different lake mixing intensity were distinguished. The local landscape was more open during phases of intensified human impact and catchment deforestation, leading to the intensification of lake mixing. At times of negligible human impact, the catchment was mostly wooded, and thus the lake was well sheltered from intense wind-driven mixing. This led to periods of prolonged anoxia. The Fe/Mn record accurately traced past changes in lake mixing intensity and related shifts in water column oxygenation. During the last two millennia, the mixing regime of Lake Żabińskie mostly depended on human activity in the catchment and landscape openness, while long periods of anoxia were not exclusive to only the most recent sediments. Graphical abstract Unlabelled Image Highlights • 2000 year-long, annually resolved record of lake mixing regime changes • The Fe/Mn ratio is tested as a proxy for past water oxygenation changes. • Human-induced landscape changes forced shifts in the lake mixing pattern. • Pre-industrial human impact played important role for the water column oxygenation. [ABSTRACT FROM AUTHOR]