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Climate change is currently a global problem, as it significantly affects the dynamics of vegetation. The objective of this research is to analyze the influence of climate variability on the dynamics of vegetation in the Portoviejo river basin. The methodology consisted in the calculation of the NDVI with the use of multispectral images from the Landsat satellite and the analysis of the fluviometric records. The images were downloaded from the Earth Explorer geospatial platform with a spatial resolution of 30 m, images from the period 1998-2019 were selected to analyze their temporal trend. The historical fluviometric records of the Portoviejo station, of the National Institute of Hydrology and Meteorology were used. The results showed that the vegetation experienced a discontinuous greening trend, influenced by the variability of rainfall. A homogeneous trend was found in the spatial distribution of the NDVI, with dense and very dense vegetation cover in the upper part of the basin, as well as little or no cover in the lower part. The area with the greatest coverage corresponded to dense vegetation with a percentage higher than 30%.

The objective of this study is to examine the potential of SCATSAT-1 data for estimating the soil moisture and vegetation over the continental regions by evaluating the variabilities in backscatter...

As vegetation cover senesces across temperate watersheds, the potential for soil erosion and subsequent sediment yields increases. Despite the importance of vegetation dynamics and evapotranspirati...

A pollen study was conducted on an alpine marsh sediment in the Son Kul Basin and was allowed to reconstruct changes in vegetation dynamics and climatic information in the western Tianshan Mountains during the past 2000 years. Pollen diagram reveals that regional vegetation is dominated by alpine meadow in the past 2000 years, being similar with modern vegetation components in the basin. The Artemisia/Chenopodiaceae-indicated moisture exhibits a warm-dry Roman Warm Period (RWP, ∼0–∼500 AD), a cold-dry Dark Ages Cold Period (DACP, ∼500–∼800 AD), a warm-wet Medieval Warm Period (MWP, ∼800–∼1350 AD), a cold-dry Little Ice Age (LIA, ∼1350–∼1850 AD) and a warm-dry Current Warm Period (CWP, since ∼1850 AD). Our pollen-based moisture reconstructions are supported by other nearby moisture records. Combined with other pollen data in the western Tianshan Mountains, we found that the vegetation was relatively stable before ∼1650–∼1750 AD and the anthropogenic activities obviously intensified afterwards (especially at the middle-elevation sites). Further work involving more and higher-resolution palaeovegetation records would contribute to fully understand the information on the complex links between environmental, climatic and anthropogenic changes in the western Tianshan Mountains.

Understanding past and future vegetation dynamics is important for assessing the effectiveness of ecological engineering, designing policies for adaptive ecological management, and improving the ecological environment. Here, inter-annual changes in vegetation dynamics during 2000–2020, contributions of climate change (CC) and human activities (HA) to vegetation dynamics, and sustainability of vegetation dynamics in the future were determined in Gannan Prefecture (a typical alpine region in the Tibetan Plateau), China. MODIS-based normalized difference vegetation index (NDVI), air temperature, precipitation, and land cover data were used, and trend analysis, multiple regression residuals analysis, and Hurst exponent analysis were employed. NDVI increased at a rate of 2.4 × 10−3∙a−1 during the growing season, and vegetation improved in most parts of the study area and some sporadically degraded areas also existed. The increasing rate was the highest in the Grain to Green Project (GTGP) areas. The vegetation in the southern and northern regions was mainly affected by CC and HA, respectively, with CC and HA contributions to vegetation change being 52.32% and 47.68%, respectively. The GTGP area (59.89%) was most evidently affected by HA. Moreover, a Hurst exponent analysis indicated that, in the future, the vegetation in Gannan Prefecture would continuously improve. The study can assist in formulating ecological protection and restoration projects and ensuring sustainable development.

General We performed simulations over sites with the global terrestrial model state-of-the-art QUINCY for sites covering the high-Arctic. These simulations server to improve quantifications of impacts caused by nitrogen mobilized following the thaw of permafrost, both for vegetation growth and soil processes. In a model version that was extended for a better representation of high latitudes, we performed sets of simulations to seperate effects that arise from increased nutrient release from thawing of permafrost soil, changes in the physical climate, as well as atmospheric CO2 fertilization. In addition to this, we constructed GPP estimates from eddy-covariance towers, as well as seasonalities of thaw depths using soil temperature data. Methods Modelled data was simulated with the fully coupled QUINCY (QUantifying Interactions between terrestrial Nutrient CYcles and the climate system) model (see model code: 10.17871/quincy-model-2019, QUINCY gitlab commit 1868232970ea4f8dbfd75c12f918ca32d43ea3ae). We extended the model with important high-latitude processes (soil freezing, snow, dynamic rooting depths). We used University of East Anglia Climatic Research Unit Japanese Reanalysis (CRU-JRA; Harris, 2019) atmospheric forcing to drive the model for 1901 to 2018, using only the 1960-2018 time frame for our analysis. We conducted three sets of simulations. climate+withoutpermafrostCNP considers changes in climate, but initialising carbon and nutrients contents to exponentially decrease with depth, as in the standard model. By doing this, C, N and P contents at depth are close to zero, thus excluding any potential fertilization effect linked to a deepening active layer. The second set of simulations was again driven by changing climate (climate), but this time also considering the release of carbon and nutrient pools from previously permanently-frozen layers, i.e. release from the permafrost. The third set of simulations additionally considered the impact of increasing atmospheric CO2 levels on vegetation dynamics and carbon cycle processes (climate+CO2). Annual timeseries are found in annual_data_1960_2018.zip, weekly climatologies are found in seasonal_data_1998_2018.zip, eddy-covariance-derived seasonalities are given in eddyfluxcovariance_data.zip. Individidual file descriptions and units are given in README.txt. The data described here is used in the publication: Lacroix et al. Mismatch of N release from the permafrost and vegetative uptake opens pathways of increasing nitrous oxide emissions in the high Arctic. Accepted for publication in Global Change Biology. https://doi.org/10.1111/gcb.16345 References Harris, I.C. (2019): CRU JRA v1.1: A forcings dataset of gridded land surface blend of Climatic Research Unit (CRU) and Japanese reanalysis (JRA) data; Jan.1901 - Dec.2017. Centre for Environmental Data Analysis, 25 February 2019. doi:10.5285/13f3635174794bb98cf8ac4b0ee8f4ed., Funding: Deutsche Forschungsgemeinschaft, Award: GO1380/3-1 Deutsche Forschungsgemeinschaft, Award: SCHA1322/12-1 Deutsche Forschungsgemeinschaft, Award: 390683824

We used a high-resolution lacustrine pollen record from Étang Fer-de-Lance (45°21′21.9′N, 72°13′35.3′W), southeastern Québec, Canada, together with microcharcoal, to infer forest dynamics and human impacts over the past 2300 years. The lake is located in the eastern sugar maple-basswood forest domain of the Northern Temperate Forest of eastern North America. We found that the pollen percentages and influxes of Fagus grandifolia (American beech) and Tsuga canadensis (eastern hemlock) significantly declined over the past 700 years. Over the last millennium, the pollen percentages and influxes of the Picea species ( P. glauca, P. mariana, P. rubens) (white, black, and red spruce), and Pinus strobus (eastern white pine) significantly increased. We showed that these shifts in forest composition are being driven by changes in regional climate. In addition to the pollen percentage changes, the Medieval Climate Anomaly (AD 800–1300) appeared as increased pollen influxes and the Dark Ages Cold Period (AD 400–700) and Little Ice Age (AD 1400–1800) appeared as decreased pollen influxes. The signal for human modification of the landscape first appeared at ~AD 1550–1650 as increases in Ambrosia (ragweed) and Poaceae (grasses) from possible Indigenous agriculture. The signal of European settler landscape modification appeared at ~AD 1770 as the beginning of a steep, “classic” Ambrosia rise. It intensified over the subsequent 250 years as further increases in non-arboreal pollen taxa and early successional Acer (maple) species. Microcharcoal analysis showed that fire was a re-occurring event in the sugar maple-basswood domain, but had little impact on forest composition.

Forests play a key role in global ecosystem conservation and environmental maintenance. Forestry, which includes plant active components, germplasm resources and vegetation dynamics, has received s...

The present study conducted in the northern zone of Niger aims to show the impact of land use dynamics on woody vegetation. The methodological approach consisted in making in addition to the floristic surveys, the analysis of land use maps (LANDSAT images of the years 1975 and 2018). The floristic inventory allowed the identification of twenty-seven (27) woody species of which eleven (11) in Tanout and sixteen (16) in Aderbissinat. The most important families remain the Fabaceae-Mimosoideae which represent 37.5% at Aderbissinat and 45.45% at Tanout. The biological types remain dominated by microphanerophytes which dominate (86.67%), while for the phytogeographic types it is the Sudano-Zambezian and Sudanian species that dominate, with proportions respectively equal to 31.25%. There is a regression of woody vegetation at the level of these communes with a slight loss in Aderbissinat (60588,034 ha) and an accentuated degradation of vegetation in Tanout (781797,738 ha).

Fire has a long history in Australia and is a key driver of vegetation dynamics in the tropical savanna ecosystems that cover one quarter of the country. Fire reconstructions are required to understand ecosystem dynamics over the long term but these data are lacking for the extensive savannas of northern Australia. This paper presents a multiproxy palaeofire record for Marura sinkhole in eastern Arnhem Land, Northern Territory, Australia. The record is constructed by combining optical methods (counts and morphology of macroscopic and microscopic charcoal particles) and chemical methods (quantification of abundance and stable isotope composition of pyrogenic carbon by hydrogen pyrolysis). This novel combination of measurements enables the generation of a record of relative fire intensity to investigate the interplay between natural and anthropogenic influences. The Marura palaeofire record comprises three main phases: 4600–2800 cal BP, 2800–900 cal BP and 900 cal BP to present. Highest fire incidence occurs at ~4600–4000 cal BP, coinciding with regional records of high effective precipitation, and all fire proxies decline from that time to the present. 2800–900 cal BP is characterised by variable fire intensities and aligns with archaeological evidence of occupation at nearby Blue Mud Bay. All fire proxies decline significantly after 900 cal BP. The combination of charcoal and pyrogenic carbon measures is a promising proxy for relative fire intensity in sedimentary records and a useful tool for investigating potential anthropogenic fire regimes.

Alaska’s Yukon–Kuskokwim Delta (YKD) is among the Arctic’s warmest, most biologically productive regions, but regional decline of the normalized difference vegetation index (NDVI) has been a striking feature of spaceborne Advanced High Resolution Radiometer (AVHRR) observations since 1982. This contrast with “greening” prevalent elsewhere in the low Arctic raises questions concerning climatic and biophysical drivers of tundra productivity along maritime–continental gradients. We compared NDVI time series from AVHRR, the Moderate Resolution Imaging Spectroradiometer (MODIS), and Landsat for 2000–19 and identified trend drivers with reference to sea ice and climate datasets, ecosystem and disturbance mapping, field measurements of vegetation, and knowledge exchange with YKD elders. All time series showed increasing maximum NDVI; however, whereas MODIS and Landsat trends were very similar, AVHRR-observed trends were weaker and had dissimilar spatial patterns. The AVHRR and MODIS records for time-integrated NDVI were dramatically different; AVHRR indicated weak declines, whereas MODIS indicated strong increases throughout the YKD. Disagreement largely arose from observations during shoulder seasons, when there is partial snow cover and very high cloud frequency. Nonetheless, both records shared strong correlations with spring sea ice extent and summer warmth. Multiple lines of evidence indicate that, despite frequent disturbances and high interannual variability in spring sea ice and summer warmth, tundra productivity is increasing on the YKD. Although climatic drivers of tundra productivity were similar to more continental parts of the Arctic, our intercomparison highlights sources of uncertainty in maritime areas like the YKD that currently, or soon will, challenge historical concepts of “what is Arctic.”

In this study, the relationship between vegetation dynamics and atmospheric patterns over Iceland from 2001-2019 has been assessed using remote sensing. This study is based on MODIS NDVI images, NCEP/NCAR reanalysis dataset and values of the North Atlantic Oscillation (NAO). The results show that the vegetation coverage in Iceland reaches a maximum in the period from the middle of July to late August, with an average of about 65% of the total area (66858 km2). There is not a strong relationship between NAO phases and the occurrence of the dry (less vegetation) or green months, which means that a dry year can be accompanied by a negative NAO phase (i.e. July 2009 with NDVI anomaly=-3.35 and NAO =-2.15) or with a positive phase (September 2005 with NDVI anomaly=-2.23 and NAO=0.63). The most important factor influencing the occurrence of months with denser/less dense vegetation is shifting west/eastward of Greenland Low height (GL), which is accompanied by a green/dry month in Iceland, respectively. The knowledge of this can help us to understand the variations in Iceland's vegetation and also enables us to have a closer look at the impact of changes in global atmospheric patterns on the vegetation productivity in Iceland.

The present study analyzes the correspondence between charcoal concentrations and changes in the palynological composition in a core from Aguas Claras peatland (30o06’24.39” S; 50o49’04.90” W) in the coastal plain of southernmost Brazil (Rio Grande do Sul State) from approximately 38,900 yrs BP until 1,500 yrs BP. The dominance of grassland vegetation (mainly Poaceae) in Late Pleistocene sediments persisted into the Holocene during the development of a peatland. Analysis of fragment size distribution and concentration were useful to discriminate local fires from regional wildfires. Late Pleistocene regional fires registered in shallow pond deposits (older than 21,545 cal yrs BP) were distinguished from a local Holocene fire by the presence of higher proportions of small particles in charcoal assemblages. A charcoal peak related to a natural fire signal, composed by high concentration of charcoal with larger diameters, was identified at the topmost level of the peat facies (1,590–1,515 cal yrs BP). Correlated with palynological data, this charcoal peak originated by local fires indicates a change in vegetation during a dry climate interval that occurred around 1,500–1,600 yrs BP. Keywords: charcoal peak, palynology, climate, Holocene. RESUMO – O presente estudo analisa a correspondencia entre as concentracoes de carvao vegetal e as alteracoes na composicao palinologica em um testemunho sedimentar da turfeira de Aguas Claras (30o06’24,39” S; 50o49’04,90”O) na planicie costeira do extremo sul do Brasil (Rio Grande do Sul) em um intervalo de cerca de 38.900 anos AP a 1.500 anos AP. A dominância de vegetacao herbacea (principalmente Poaceae) no intervalo glacial tardio do Neopleistoceno persistiu ate o Holoceno, durante o desenvolvimento de uma turfeira. A analise da distribuicao e concentracao de tamanho dos fragmentos de charcoal foi utilizada para distinguir incendios florestais locais de incendios regionais. Incendios regionais no Neopleistoceno (mais antigos do que 21.545 anos cal AP) foram diferenciados de um incendio local do Holoceno, dadas as grandes quantidades de pequenos fragmentos de charcoal com diâmetros semelhantes. Um pico de charcoal que corresponde a um sinal incendio natural, composto por alta concentracao de fragmentos com grandes diâmetros indicando incendio local, foi identificado no nivel de topo de facies originadas em turfeira (1.590–1.515 anos cal AP). Esse pico de charcoal, correlacionado aos dados palinologicos, indicou uma mudanca na vegetacao relacionada a um intervalo climatico de seca que ocorreu por volta de 1.500–1.600 anos AP. Palavras-chave: pico de carvao vegetal, palinologia, clima, Holoceno.

We analyzed phytosociological characteristics of a tropical dry deciduous forest located in an urban environment of Indian Institute of Forest Management (IIFM) Campus in the capital city of Bhopal of Madhya Pradesh state, Central India. A Comparison has been made among the tree community characteristics during the years 1988, 2002 and 2020 in terms of tree species composition, stem density, basal area and Importance Value Index (IVI). At the time of establishment of the institute in 1988, the forest area resembleda degraded dry scrubland. Due to continuous care/protection, plantation activities, degraded forest recovered remarkably, ecological processes evolved favorably with canopy cover reaching over 60% in some patches and about 50% in general over most part of the campus. During last two decades, tree density increased from 319 to 525 stem ha-1 indicating an increase of 64% whereas basal area increased from 18470.79 cm2 ha-1 to 29782.31 cm2 ha-1,an increase of about 61%. Leguminaceae family represented 26.4% of the tree community followed by Combretaceae (11.76%). Shannon-Weiner index (1.31), Simpson index (0.93) and evenness index (0.85) are within the reported ranges for similar forest type of dry deciduous nature in India. Theresults of the presentstudy will help forest managers in conservation planning of urban tropical forest ecosystem of central India.

Editorial of the Special Feature 'Dispersal and Establishment'.

In Europe, mountain landscapes have evolved in a long‐term relationship with human communities and present‐day landscapes reflect that ancient interaction. The present study aims to reconstruct human activity in twomountain areas in northern Portugal using palynological analysis integrated with the available regional historical,archaeological and palaeo environmental archives. Pollen records from two sedimentary sequences span the Medieval and Modern periods and show that mixed agriculture and livestock grazing were consistently present in both regions throughout these times. Variations in cultural indicators show that the extent of farming fluctuated throughout time, with a general increase in cultivation during the Medieval period but with contractions likely coinciding with times of social disturbance. Historical sources suggest that sociopolitical factors and population pressure were fundamental in the utilisation of upland spaces. This study did not find any convincing evidence to suggest that fire was a fundamental factor in heathland spread. We conclude that long‐term occupation of the uplands was sustained by low‐intensity land use throughout the Medieval to post‐Medieval periods, and that the present landscape has assumed a very different character following depopulation of the mountain areas and a shift towards commercial forestry.© 2020 The Authors. Journal of Quaternary Science Published by John Wiley & Sons Ltd

The Grain for Green Project in China’s Loess Plateau has significantly increased the vegetation coverage (M) since it was implemented in 1999. Accurately modelling evapotranspiration (ET) and attributing its changes are important for assessing the hydrological effects of revegetation in this area. Budyko-based models have been widely used to estimate ET whereby the controlling parameter (ω) captures the effects of land surface conditions and climate seasonality. Although the effects of climate seasonality on ET variation have been theoretically discussed, its important role in ω remains further investigation. An improved climate seasonality and asynchrony index (SAI) was thus used to reflect the seasonality and asynchrony of water and energy distribution in this study. Then ω was extended to M and SAI at grid scale to model annual ET by linking Fu equation in China’s Loess Plateau for the period 1981–2012. Further, the whole study period was split into two sub-periods at the year of 1999, and then the complementary method was used to quantify the contributions of precipitation (P), potential evapotranspiration (E0), M and SAI changes to ET variation between the two sub-periods. The results showed that ET increased by 5.1 mm/yr after 1999. ET is most sensitive to changes in P, followed by M, E0, and SAI. However, increasing M dominated the overall increase in ET, outweighing the effects of decreasing P and increasing SAI. Because SAI accounted for almost a third of total ET change, the impacts of climate seasonality cannot be ignored in ET simulation and attribution analysis.

In order to understand the mechanism of preserving cobble-bar vegetation, a vegetation dynamics field survey and numerical simulation of flood flows have been conducted. The study focuses on sparse perennial community established on cobble bars of a river in Japan. The field survey conducted over ten years reveals the existence of special spots where small number of individuals survive large floods providing refugia for the species. Three-dimensional simulation further identified that the locations of refugia correspond to the low bed-shear force area created by the complex three-dimensional flow downstream of cobble bars that develop on the inner side of sharp bends. The sudden steep drop downstream of the bar that is needed for the low shear region appears to be maintained by the secondary flow associated with the sharp bend.

Palynology is a multi-disciplinary field of science that deals with the study and application of extinct, [fossilised] and extant palynomorphs (pollen and spore) and other related microscopic biological entities in the environment. It is divided into palaeo- and actuo-palynology, and provides substantial proxies to understanding past and present vegetation dynamics respectively. With reference to the two geological principles of uniformitarianism and of the evolution of fauna/flora, the distribution of plant indicators across ecological zones, palynomorph morphology and pollen analysis, palynology can be used to identify the change in past and present local and regional vegetation and climate and humans impact on the environment. Other supportive areas of endeavour like radiocarbon dating, sedimentology, taphonomic processes and geomorphology can be used to triangulate inferences drawn from palynological data. Palynomorphs are made of outer cell walls embedded with an inert, complex and resistant biopolymeric signature (called sporopollenin) which helps to facilitate long term preservation in different environmental matrices under favourable conditions, hence its widespread applicability. Palynology have proven to very reliable in reconstructing past vegetation, decrypting essential honeybee plants and understanding the impact of climate on plant population using pollen analysis, for which is the basis for the application of palynology in environmental studies. The application of palynology in climate, vegetation and anthropogenic studies begins with the selection of matrix (sediments from lake, river, ocean, excavation, relatively intact soil profile, bee products), coring or collection of samples, subjection to a series of chemically aided digestion, separation, physical filtration, decanting, accumulating of palynomorphs, microscopic study and ends with the interpretation of recovered information. Literature review on the application of palynology for understanding vegetation and climate interactions is presented in this paper.

The North Atlantic region experienced abrupt high-amplitude cooling at the onset of the Younger Dryas stadial. However, due to chronological uncertainties in the available terrestrial records it is unclear whether terrestrial ecosystem response to this event was instantaneous and spatially synchronous, or whether regional or time-transgressive lags existed. Here we use new palynological results from a robustly dated lake sediment sequence retrieved from lake Hämelsee (north Germany) to show that vegetation change started at 12,820 cal. yr BP, concurrent with the onset of changes in local climate. A comparison of the Hämelsee results to a compilation of precisely dated palynological records shows instant and, within decadal-scale dating uncertainty, synchronous response of the terrestrial plant community to Late-Glacial climate change across northwest Europe. The results indicate that the environmental impact of climate cooling was more severe than previously thought and illustrates the sensitivity of natural terrestrial ecosystems to external forcing.

The Black Sea covers an area of 432 000 km2 and is the largest anoxic basin in the world. The most recent sediment layers can be divided into three units: Unit I, the top approximately 30 cm, is a ...

Linear feature networks are the roads, trails, pipelines, and seismic lines developed throughout many commercial boreal forests. These linear features, while providing access for industrial, recreational, silvicultural, and fire management operations, also have environmental implications which involve both the active and non-active portions of the network. Management of the existing linear feature networks across boreal forests would lead to the optimization of maintenance and construction costs as well as the minimization of the cumulative environmental effects of the anthropogenic linear footprint. Remote sensing data and predictive modelling are valuable support tools for the multi-level management of this network by providing accurate and detailed quantitative information aiming to assess linear feature conditions (e.g., deterioration and vegetation characteristic dynamics). However, the potential of remote sensing datasets to improve knowledge of fine-scale vegetation characteristic dynamics within forest roads has not been fully explored. This study investigated the use of high-spatial resolution (1 m), airborne LiDAR, terrain, climatic, and field survey data, aiming to provide information on vegetation characteristic dynamics within forest roads by (i) developing a predictive model for the characterization of the LiDAR-CHM vegetation cover dynamic (response metric) and (ii) investigating causal factors driving the vegetation cover dynamic using LiDAR (topography: slope, TWI, hillshade, and orientation), Sentinel-2 optical imagery (NDVI), climate databases (sunlight and wind speed), and field inventory (clearing width and years post-clearing). For these purposes, we evaluated and compared the performance of ordinary least squares (OLS) and machine learning (ML) regression approaches commonly used in ecological modelling—multiple linear regression (mlr), multivariate adaptive regression splines (mars), generalized additive model (gam), k-nearest neighbors (knn), gradient boosting machines (gbm), and random forests (rf). We validated our models’ results using an error metric—root mean square error (RMSE)—and a goodness-of-fit metric—coefficient of determination (R2). The predictions were tested using stratified cross-validation and were validated against an independent dataset. Our findings revealed that the rf model showed the most accurate results (cross-validation: R2 = 0.69, RMSE = 18.69%, validation against an independent dataset: R2 = 0.62, RMSE = 20.29%). The most informative factors were clearing width, which had the strongest negative effect, suggesting the underlying influence of disturbance legacies, and years post-clearing, which had a positive effect on the vegetation cover dynamic. Our long-term predictions suggest that a timeframe of no less than 20 years is expected for both wide- and narrow-width roads to exhibit ~50% and ~80% vegetation cover, respectively. This study has improved our understanding of fine-scale vegetation dynamics around forest roads, both qualitatively and quantitatively. The information from the predictive model is useful for both the short- and long-term management of the existing network. Furthermore, the study demonstrates that spatially explicit models using LiDAR data are reliable tools for assessing vegetation dynamics around forest roads. It provides avenues for further research and the potential to integrate this quantitative approach with other linear feature studies. An improved knowledge of vegetation dynamic patterns on linear features can help support sustainable forest management.

The Hanjiang River Basin (HJRB) is an important water conservation and ecological barrier area for the South–North Water Transfer Central Project. The quantitative analysis of regional differences in vegetation changes and their main drivers is important for the monitoring of the ecological environment of the basin and formulation of ecological protection measures. Based on MODIS13Q1 data from 2000 to 2020, spatiotemporal variation characteristics of vegetation in the HJRB were analyzed using Theil–Sen + Mann–Kendall, the Hurst index, and correlation analysis. Then, we detected the drivers using an optimal parameter geographic detector. The results showed that from 2000 to 2020, the average NDVI value increased from 0.651 to 0.737, with a spatial distribution pattern of “high in the northwest and low in the southeast”, and 88.68% of the study area showed an increase in vegetation cover, while 5.80% showed a significant degradation. The positive persistence of future vegetation changes is stronger than the negative. It may show a slowdown or degradation trend, among which the vegetation restoration along the Han River and urbanized areas need to be strengthened. The factor detector indicated that the main factors influencing vegetation change were topography and climate, for which the most influential variables, respectively, were elevation (0.1979), landform (0.1720), slope (0.1647), and soil type (0.1094), with weaker influence from human activity factors. The interaction test results showed that the interaction of various geographic factors enhanced the explanatory power of vegetation changes and showed mainly nonlinear and two-factor enhancements. The dominant factor varies between sub-basins; for example, the interaction between wind speed and land use conversion was the dominant factor in the middle reaches of the HJRB; the dominant factor in the lower reaches of the HJRB was expressed as the interaction between land use conversion and temperature. Finally, the effects of the range or category of different drivers on vegetation growth were systematically analyzed. The results of the study contribute to the understanding of the dynamic changes of vegetation based on a comprehensive consideration of the interaction of topography, climate, and human activities, taking into account the totality and variability of the geographical environment, and provide a reference for the ecological restoration and rational use of vegetation resources in the HJRB.

To tackle ecological problems, many ecological restoration projects have been implemented in northern China. Identifying the drivers of vegetation change is critical for continued ecological engineering. In this study, three typical ecological reserves in the Three-North Shelter Forest Program Region (TNSFR) were selected to identify their vegetation development characteristics and driving mechanisms using the normalized difference vegetation index (NDVI), climate factors, and land use data. The results show that (1) NDVIs increased in the range of human activities of all of the three ecological reserves, indicating an obvious effect of the vegetation restoration projects. (2) In the planting period, vegetation restoration was mainly correlated with human activities. After entering the tending period, the impact of climate changes on vegetation dynamics was enhanced. (3) Temperature and precipitation provided approximate driving effects on vegetation dynamics in Region I, while vegetation dynamics in Regions II and III were more strongly correlated with precipitation. (4) The proportion of areas with ecological measures exceeded 50% in all three regions. In short, ecological projects in the three ecological reserves dominated the quantity of vegetation restoration, while climate changes influenced the quality of vegetation restoration.

Global land cover dynamics alter energy, water, and greenhouse gas exchange between land and atmosphere, affecting local to global weather and climate change. Although reforestation can provide localized cooling, ongoing land use land cover (LULC) shifts are expected to exacerbate urban heat island impacts. In this study, we monitored spatiotemporal changes in green cover in response to land use transformation associated with the Khyber Pakhtunkhwa (KPK) provincial government’s Billion Tree Tsunami Project (BTTP) and the Ravi Urban Development Plan (RUDP) initiated by the provincial government of Punjab, both in Pakistan. The land change modeler (LCM) was used to assess the land cover changes and transformations between 2000 and 2020 across Punjab and KPK. Furthermore, a curve fit linear regression model (CFLRM) and sensitivity analysis were employed to analyze the impacts of land cover dynamics on land surface temperature (LST) and carbon emissions (CE). Results indicated a significant increase in green fraction of +5.35% under the BTTP, achieved by utilizing the bare land with an effective transition of 4375.87 km2. However, across the Punjab province, an alarming reduction in green fraction cover by −1.77% and increase in artificial surfaces by +1.26% was noted. A significant decrease in mean monthly LST by −4.3 °C was noted in response to the BTTP policy, while an increase of 5.3 °C was observed associated with the RUDP. A substantial increase in LST by 0.17 °C was observed associated with transformation of vegetation to artificial surfaces. An effective decrease in LST by −0.21 °C was observed over the opposite transition. Furthermore, sensitivity analysis suggested that LST fluctuations are affecting the % of CO2 emission. The current findings can assist policymakers in revisiting their policies to promote ecological conservation and sustainability in urban planning.

A review of the vegetation history of the Northern Calcareous Alps of Germany and Austria for the montane, subalpine and alpine vegetation belts above 900 m a.s.l. is presented. Natural vegetation changes are recorded until the end of the Atlantic period. Human impact started locally in the valleys, but soon spread into higher altitude. First alpine pastoral farming is documented since the Bronze Age. Furthermore, a monitoring study of alpine and subnival vegetation dynamics as well as a grazing experiment on the Zugspitzplatt (Wetterstein Mountains) is outlined. The Zugspitzplatt is Germany’s highest investigation site with a long altitudinal gradient from 2000 to 2700 m providing excellent conditions. Along with the specific site climate, pedogenetic processes, and soil conditions show considerable variation in the investigation area. The vegetation on these sites is highly influenced by anthropo-zoogenic impact.

The temporal resolution of vegetation indices (VIs) determines the details of seasonal variation in vegetation dynamics observed by remote sensing, but little has been known about how the temporal ...

Currently, the use of numerical models for reproducing the evolution of river systems and landscapes is part of the day-by-day research activities of fluvial engineers and geomorphologists. However, despite landscape evolution modelling is based on a rather long tradition, and scientists and practitioners are studying how to schematize the processes involved in the evolution of a landscape since decades, there is still the need for improving the knowledge of the physical mechanisms and their numerical coding. Updating past review papers, the present work focuses on the first aspect, discussing six main components of a landscape evolution model, namely continuity of mass, hillslope processes, water flow, erosion and sediment transport, soil properties, vegetation dynamics. The more common schematizations are discussed in a plain language, pointing out the current knowledge and possible open questions to be addressed in the future, towards an improvement of the reliability of such kind of models in describing the evolution of fluvial landscapes and river networks.

In this study, we quantified the vegetation changes in the Haihe river basin (HRB) and analyzed their drivers during 1982–2012 by using satellite normalized difference vegetation index (NDVI) data,...

With the increasing demand for global water resources and general deterioration of the ecological environment of the Qinghai-Tibetan Plateau, changes to the water conservation functions of ecosystems and the impact mechanisms have attracted great attention. Currently, the research on water conservation has mainly focused on a single biome type, in particular, forests. Few studies explore the differences in water conservation functions of different biome types. Research on this topic mostly utilizes field investigations and sample plot settings to explore the differences in water conservation capacity of a small number of tree species, but these methods are limited in time and space. Therefore, this study uses MODIS products to evaluate the water conservation function of different biome types in the Qinghai-Tibetan Plateau. Dynamic monitoring of the vegetation and water conservation capacity in the study area and research on the responses of the water conservation functions of different biome types were conducted. The results indicate that the vegetation of the Qinghai-Tibetan Plateau increased slightly from 2000 to 2015; however, due to the dual influence of climate and topographic factors, the water conservation capacity showed a slight decline. The water conservation service function mainly comes from grassland ecosystems, which are closely related to vegetation density and biome types. Therefore, to greatly improve the water conservation service function of the Qinghai-Tibetan Plateau, the management and planting of vegetation should be conducted according to the optimal vegetation coverage area, vegetation quantities and biome types.

Climate-induced forest mortality is being widely observed across the globe. Predicting forest mortality remains challenging because the physiological mechanisms causing mortality are not fully understood and empirical relations between climatology and mortality are subject to change. Here, we show that the temporal loss of resilience, a phenomenon often detected as a system approaches a tipping point, can be used as an early warning signal (EWS) to predict the likelihood of forest mortality directly from remotely sensed vegetation dynamics. We tested the proposed approach on data from Californian forests and found that the EWS can often be detected before reduced greenness, between 6 to 19 months before mortality. The EWS shows a species-specific relation with mortality, and is able to capture its spatio-temporal variations. These findings highlight the potential for such an EWS to predict forest mortality in the near-term. Predicting mortality in forests is challenging because its underlying causes are spatially varied and not well known. Reduced resilience detected from remotely sensed time series of vegetation dynamics can serve as an effective early warning signal to indicate the potential for forest mortality.

Vegetation dynamics are known to influence belowground microbial community diversity and ecosystem processes in wetlands. However, the knowledge on microbe–microbe interactions in response to vegetation changes is scarce. In this study, we investigated how bacterial and fungal community composition, as well as bacterial–fungal community interactions, altered along a vegetation gradient in the Poyang Lake wetland. Surface soil and sediment samples were collected from three vegetation zones: dense, sparse, and naked. Vegetation zones differed in terms of dominant plant species, plant diversity, and vegetation coverage. Using Illumina MiSeq sequencing and network analysis of bacteria 16S rRNA and fungal ITS genes, we found that both bacterial and fungal community profiles varied according to vegetation conditions; in particular, the dense vegetation zone facilitated higher microbial abundance and a greater fungi to bacteria ratio. Co-occurrence analysis revealed that fungi–bacteria interactions were strong on vegetated zones, especially in the dense vegetation zone. However, a weak fungi–bacteria association was observed in the naked zone. Our results indicated that aboveground vegetation may act as a hotspot for organic matter accumulation, microbial growth, and microbe–microbe interactions, whereas fungi and bacteria prefer to distribute into niches based on their own nutritional preferences and functional specificity in bare ground.