Removal Of Vegetation Research Articles

Water quality, vegetation, and management of stormwater ponds draining three distinct urban land uses in central Florida

Stormwater ponds are prevalent engineered water features that are designed to mitigate the effects of urban land use on downstream water bodies. These systems contribute significantly to the total area of aquatic ecosystems in some urban watersheds, making them important integrative features for examining human impacts on water ecosystem services. We investigated the distribution of stormwater ponds in relation to different land uses and examined dissolved nutrients in pond water, pond vegetation, and pond management practices in stormwater ponds receiving runoff from distinct urban lands uses in a rapidly developing suburban watershed of Orlando, FL, USA. Stormwater ponds represented 40.2% of the total area of non-forested freshwater systems in the watershed and were dominated by ponds situated in residential (43.7%), followed by roadways (14.7%), and institutional (2.3%) land uses. We randomly selected 8 ponds receiving runoff from each of these three lands uses, using schools to represent the institutional land use, and expressways to represent roadways, and sampled them monthly from May-Sept. 2015 for nutrient and physical characteristics and assessed their general cover of emergent and submerged vegetation. Total nitrogen (TN) concentrations differed significantly between expressway and school ponds, with expressway ponds having TN concentrations 51.7% higher than schools. Both total phosphorus (TP) and TN varied differently through time in the different lands uses and concentrations of most dissolved nutrients separated out from pond vegetative cover in a principal component analysis. Ponds with higher TN and chlorophyll a (chla) concentrations had lower water clarity. Management intensity for removal of aquatic vegetation and algae was lower in school ponds than in expressway and residential ponds, and school ponds contained the highest abundance and diversity of vegetation. Different urban land uses had varying impacts on water quality, and more intense chemical use to control vegetation and algae was related to greater nutrient and chla concentrations and lower water clarity. Our results indicate that there are important differences in nutrient concentration in stormwater ponds in the different land uses that may be related both to differences in surface runoff, and in management practices use to control overgrowth of vegetation and algae.

Side effects of European eco schemes and agri-environment-climate measures on endangered species conservation: Clues from a case study in mountain vineyard landscapes

In Europe, the Common Agricultural Policy (CAP) encouraged the specialisation of agriculture and forestry systems by supporting schemes that promoted productivity, despite the socio-ecological changes’ detrimental effects on ecosystem services and biodiversity. In the case of mountain viticulture of southern Europe, the adoption of intensive management techniques triggered noticeable changes in farming systems, namely the removal of traditional stonewalls and semi-natural vegetation, partially compensated by eco schemes and agri-environment-climate measures. By combining fieldwork information with spatio-temporal modelling techniques, a novel hybrid framework is explained and implemented to predict the population trends of a critically endangered bird species in Portugal, the Black Wheatear (Oenanthe leucura), to the individual and/or combined effects of the removal of traditional stonewall terraced vineyards and the implementation of cover crops. The results obtained demonstrate the relevance of stonewall terraced vineyards (and the negative effects of their removal) for the conservation of Black Wheatear, namely during the breeding season when holes and crevices are used for nesting. Conversely, and in accordance with our simulations, the increase in the area occupied by vineyards with cover crops seems particularly detrimental for the species, by decreasing the quality of the feeding grounds. As cover crops, and possibly other eco schemes and agri-environment-climate measures, might not be the panacea for halting biodiversity loss in mountain viticulture, adaptation of measures to species’ ecological requirements is urgent for a successful EU biodiversity strategy for 2030.

Methodological Framework for Assessing Hydromorphological Conditions of Heavily Modified and Artificial River Water Bodies in Croatia

Water Framework Directive (WFD) guidance documents from 2019 provide a comprehensive review of methods and guidelines to improve the comparability of heavily modified water bodies (HMWBs) in the European Union. However, there is currently no common, single methodology for monitoring HMWBs and artificial water bodies (AWBs) or for determining maximum (MEP) and good ecological potential (GEP). This study presents the first assessment of hydromorphological conditions of HMWBs and AWBs in Croatia based on type-specific indicators. The typology of HMWBs and AWBs was based on distinct hydromorphological characteristics and modifications in order to be easily related to the uses of the water bodies. The classes of hydromorphological potential were graded from the theoretical MEP, which was determined by the score scale as the tolerated deviation from natural reference conditions, considering potential mitigation measures. The use of the water body and/or the effects on the wider environment were considered while determining MEP and choosing indicators included in monitoring and assessment. In the case of AWBs, the parameters dependent on natural reference conditions, which are non-existent, were omitted from the assessment. Only 27% of HMWBs and 2 out of 51 AWBs achieved good potential for all three hydromorphological elements. The most significant hydromorphological modifications include channelization, straightening, deepening and removal of riparian vegetation due to flood-protection management practices. In order to achieve the environmental objectives set out by the WFD, the Croatian water management system has to start implementing mitigation measures, especially related to natural flood management.

Sand lizards (Lacerta agilis) decrease nymphal infection prevalence for tick‐borne pathogens Borrelia burgdorferi sensu lato and Anaplasma phagocytophilum in a coastal dune ecosystem

Abstract Understanding which factors determine tick‐borne disease hazard can contribute to effective disease control. In Europe, the hazard of the pathogens Borrelia burgdorferi s.l. and Anaplasma phagocytophilum is determined by local tick densities (mainly Ixodes ricinus) and the reservoir competence of the host species community. Sand lizards (Lacerta agilis) are common hosts for larvae and nymphs of I. ricinus and non‐competent reservoirs for both pathogens. Consequently, high relative abundance of L. agilis is hypothesized to be associated with lower infection prevalence in nymphs. Here, we aimed to test whether this effectively occurs in natural settings. We sampled different habitat types within a heterogenous dune landscape at the Dutch coast and estimated (1) L. agilis densities, (2) host community competence, (3) the density and infection prevalence of questing I. ricinus ticks and (4) the number and infection prevalence of ticks feeding on L. agilis. Captured L. agilis had high tick burdens and contributed substantially to feeding I. ricinus larvae in their natural habitat. B. burgdorferi s.l. and A. phagocytophilum were virtually absent from feeding larvae and nymphs. The nymphal infection prevalence of both pathogens in questing ticks was lower in habitat types where L. agilis was more abundant. Hence, L. agilis strongly reduced community competence. The density of questing nymphs was higher in habitat types with denser vegetation and also varied more between habitat types than infection prevalence. As a result, nymphal density had a stronger effect on the density of infected ticks than did nymphal infection prevalence. Synthesis and applications. Coastal dune habitats favourable for L. agilis have lower densities of questing nymphs and a lower human infection hazard. These results might be applicable to similar ecosystems where L. agilis is present. From a public health perspective, this underlines the importance of preserving early successional habitat, as encroaching shrubs are associated with higher tick‐borne disease hazard, and vegetation removal might be a solution to reduce hazard in coastal dunes. The high degree of spatial heterogeneity in the abundance of tick‐borne pathogens also poses opportunities to manage recreational activities to limit human exposure to tick‐borne diseases.

Effects of Land Use and Cropping on Soil Erosion in Agricultural Frontier Areas in the Cerrado-Amazon Ecotone, Brazil, Using a Rainfall Simulator Experiment

Agricultural soils provide ecosystem services, but the removal of natural vegetation reduces water infiltration capacity, increasing surface runoff. Thus, monitoring erosion is critical for sustainable agricultural management. Sediment losses and surface runoff were evaluated using a simulated rainfall of 75 mm/h in areas with crops and pastures in both the Caiabi River and Renato River sub-basins of the Teles Pires River watershed in Mato Grosso State, Brazil. In both the Caiabi and Renato sub-basins, data were collected from 156 observations in the upper, middle, and lower regions where (1) soybeans, (2) maize, and (3) pasture were grown alone, with another crop, or with soil that was scarified. Erosion occurred independent of soil texture and was closely related to the management and use of systems involving fewer crops and more soil scarification, regardless of sub-basin location. In uncovered, scarified soil, the soil losses from erosion were greater compared to covered soil, regardless of sub-basin and sub-basin region. In the Renato River sub-basin, soil losses in cultivated areas not planted with crops but with scarification were 66.01, 90.79, and 60.02 g/square meter in the upper, middle, and lower regions, respectively. Agricultural producers need to increase the planting of crops throughout the year and minimize soil disturbance, which will reduce soil erosion and improve sustainability.

Disentangling the mixed effects of soil management on microbial diversity and soil functions: A case study in vineyards

Promoting soil functioning by maintaining soil microbial diversity and activity is central for sustainable agriculture. In viticulture, soil management often includes tillage, which poses a multifaceted disturbance to the soil environment and has direct and indirect effects on soil microbial diversity and soil functioning. However, the challenge of disentangling the effects of different soil management practices on soil microbial diversity and functioning has rarely been addressed. In this study, we investigated the effects of soil management on soil bacterial and fungal diversity as well as soil functions (soil respiration and decomposition) using a balanced experimental design with four soil management types in nine vineyards in Germany. Application of structural equation modelling enabled us to investigate the causal relationships of soil disturbance, vegetation cover, and plant richness on soil properties, microbial diversity, and soil functions. We could show that soil disturbance by tillage increased bacterial diversity but decreased fungal diversity. We identified a positive effect of plant diversity on bacterial diversity. Soil respiration showed a positive response to soil disturbance, while decomposition was negatively affected in highly disturbed soils via mediated effects of vegetation removal. Our results contribute to the understanding of direct and indirect effects of vineyard soil management on soil life and aids designing targeted recommendations for agricultural soil management.

Distribution and fate of Tibetan Plateau loess

The Tibetan Plateau (TP) hosts the largest alpine ecosystem in the world, and aeolian loess is an essential component of this ecosystem and landscape. However, little is known of loess distribution and fate, owing to the climate and landscape varying dramatically between Quaternary glacial and interglacial cycles. Recent research suggests that the interior Tibetan loess did not start to accumulate until ∼14 ka, when climate warming and wetting resulted in an increase in vegetation cover, enabling dust trapping. In this study, our extensive aeolian profile review and age analysis demonstrate that loess thickness and basal ages on the TP are very different regardless of terrain and landscape. According to loess distribution, thickness, and basal ages, we divided the TP into three zones: Zone I (western TP) and Zone III (eastern TP) are the dust source and sink areas, respectively, and Zone II (central TP) is transitional. The central TP became a dust source zone during the last glacial stage but turned into a dust sink during the last deglaciation and Holocene. The modeling results confirm that each zone has its own role in dust fixation and deflation and that these three zones are systematically interlinked by dust. Glacial-interglacial precipitation and vegetation cover changes controlled the switch in Zone II (central TP). We demonstrate that dust on the TP must have experienced enhanced excavation from west to east during the past glacial periods. During the next glacial period, the eastern TP loess may continue to accumulate, but the central TP loess will be eroded after vegetation degradation and removal, leading to a serious ecological disaster. This study provides insights into Tibetan loess accumulation patterns on a large spatial scale, improving the understanding of the past of Tibet loess and enabling predictions regarding future Tibet loess.

Role of dry watercourses of an arid watershed in carbon and nitrogen processing along an agricultural impact gradient

In the Mediterranean arid region such as Southeast (SE) Spain, a considerable part of the fluvial network runs permanently dry. Here, many dry watercourses are embedded in catchments where agriculture has brought changes in carbon (C) and nitrogen (N) availability due to native riparian vegetation removal and the establishment of intensive agriculture. Despite their increasing scientific recognition and vulnerability, our knowledge about dry riverbeds biogeochemistry and environmental drivers is still limited, moreover for developing proper management plans at the whole catchment scale. We examined CO2 and N2O emissions in five riverbeds in SE Spain of variable agricultural impact under dry and simulated rewetted conditions. Sediment denitrifying capacity upon rewetting was also assessed. We found that, regardless of agricultural impact, all riverbeds can emit CO2 under dry and wet conditions. Emissions of N2O were only observed in our study when a long-term rewetting driving saturated sediments was conducted. Besides, most biogeochemical capabilities were enhanced in summer, reflecting the sensitiveness of microbial activity to temperature. Biogeochemical processing variation across rivers appeared to be more controlled by availability of sediment organic C, rather than by agriculturally derived nitrate. We found that the studied dry riverbeds, agriculturally affected or not, may be active sources of CO2 and contribute to transitory N2O emissions during rewetting phenomena, potentially through denitrification. We propose that management plans aiming to support ecosystem biogeochemistry through organic C from native vegetation rather than agricultural exudates would help to reduce anthropogenic greenhouse gases emissions and excess of nutrients in the watershed and to control the nitrate inputs to coastal ecosystems.

Quantification of Evapotranspiration and Water Chemistry in a Remediated Wetland in Everglades National Park, USA

Similar to most wetlands, the Florida Everglades landscape was altered to promote agriculture and human settlement, significantly altering the natural hydrologic regime. Once former agricultural land located within Everglades National Park (ENP), the Hole-in-the-Donut (HID) wetland restoration program became the first mitigation bank project in Florida. The HID program utilized a restoration technique of complete soil removal to effectively eradicate an invasive plant species. This research investigated the effects of the vegetation and soil removal on the hydrologic conditions of the HID, specifically evapotranspiration and water chemistry. Annual evapotranspiration rates were determined for the region using remotely sensed data and compared to the acres restored over a 15-year period. Groundwater and surface waters were collected from both inside the HID and from adjacent areas within ENP for major cations and anions and total nutrient concentrations. Evapotranspiration rates were found to decrease from a mean of 1083.4 mm year−1 in the year 2000 to 891.6 mm year−1 in 2014 as the restored area increased to 4893 acres. Concentrations of ions and nutrients were lower in groundwater and surface water within the restored areas compared to adjacent areas. We conclude that the lack of soil cover (along with reduced evapotranspiration rates) contributed to the lower ion and nutrient concentrations in the surface water and groundwater within the HID.

Cardiac and great vessels pseudoaneurysms and their challenging options of the management in children

Introduction: Cardiac and great vessel pseudoaneurysms are often difficult to diagnose and might be easily missed. Delay in diagnosis and management may lead to serious event. Case Series: We are presenting three cases with huge pseudoaneurysms. The clinical approach, diagnostic imaging, and challenging options of management were illustrated. The first case was 12 years old girl presented with clinical features of bacterial endocarditis; echocardiography showed multiple vegetations on mitral valve (MV). She underwent cardiac surgery with removal of vegetation and repair of MV. Three weeks later an echocardiogram revealed a large left ventricle (LV) lateral wall pseudoaneurysm. She underwent aneurysmectomy and repair of LV lateral wall. Second case, a 3 years old girl with history of fever for one month. Echocardiography showed LV pseudoaneurysm and huge pericardial effusion. The pseudoaneurysm entrance was closed percutaneously. The third case was 3-months baby girl diagnosed with aortic coarctation (COA), patent ductus arteriosus (PDA), and muscular ventricular septal defect. She has repair of COA, pulmonary artery band (PAB), and PDA ligation at three weeks of age. Six weeks later developed sepsis. Echocardiography and CT revealed huge pseudoaneurysm at site of COA repair. Surgical resection of the huge pseudoaneurysm was done. Conclusion: Meticulous evaluation and good utilization of the cardiac diagnostic tools will result in early diagnosis and management of the cardiac and vessel pseudoaneurysms which are usually fatal.

Soil Degradation and its Causes

In India, soil degradation is common, resulting in decreased soil productivity, deterioration of vegetative cover, qualitative and quantitative decline of soil and water resources, and air pollution. It has become significantly worse in recent decades as a result of the country's growing population, which necessitates the cultivation of marginal lands in order to fulfil the growing food demand. Poverty and natural resource depletion force people to look for more land to grow food, fodder, and fibre. Deforestation and removal of natural vegetation, overgrazing, converting forests to farms, cultivating steep slopes and degrading marginal lands, other agriculture-related activities, and overexploitation of vegetation for domestic purposes are the main causes of degradation caused by direct/indirect human intervention. Similarly, agricultural residue removal or in-situ burning is prohibited.

Obstacles to removing non-native species from a national park

Throughout its history, the National Park Service has sought to eliminate or control non-native species within its units. The growing influence of science in natural resource management has made this mandate ever more imperative. Removal of invasive vegetation has proven extremely difficult and may never be complete in many parks. Efforts to eliminate domesticated animals and feral or wild invaders have met many obstacles as well. Channel Islands National Park has managed to get rid of sheep, cattle, pigs, burros, horses, deer, elk, rats, cats, rabbits, turkeys, Argentine ants, and European honey bees. In the process, park managers have had to work through or overcome eight types of impediments as well as virulent opposition. Lessons learned from these campaigns can inform other park managers facing the same types of problems.

DENSITY-BASED METHOD FOR BUILDING DETECTION FROM LIDAR POINT CLOUD

Abstract. In this paper, a new building detection method based on a density of LiDAR point clouds is proposed. In this method, trees, vegetation, and any objects that have points in a vertical plane or column are removed. In the density-based method, a cube is utilized to calculate the density therein. For each point, the cube is used to determine the number of neighbouring points. The density is calculated in two cases: 3D and 2D space. In 3D space, the volumetric density is calculated using the cube. In 2D space, all points are projected onto the horizontal plane, and the surface density is calculated using a square. Next, the two densities are compared and the points with different values in both cases are removed. The method leads to promising results in the removal of vegetation and trees. Moreover, the results achieve more than 94% completeness and correctness at the per-area level.

Altered energy dynamics of multitrophic groups modify the patterns of soil CO2 emissions in planted forest

Soil microbes and fauna as key components of belowground food webs play important roles in energy flux and carbon cycling in terrestrial ecosystems. However, it remains unclear whether forestry management regimes alter the energetic structure of soil food webs and thereby reshape the patterns of soil CO2 emissions in planted forest. Here, we tested the effects of legume (Cassia alata) addition, understory removal, understory removal with legume addition and all plants removal on energy fluxes through soil food webs and soil CO2 flux in the wet and dry seasons. We show that soil heterotrophic respiration contributed 36.9–57.8% of total CO2 flux in the soil. In the dry season, C. alata addition increased soil heterotrophic respiration by 24.6% and 57.3%, respectively, when compared with the control and understory removal treatment. Compared with the understory removal treatment, the total energy flux across the whole food web increased with legume addition (i.e., C. alata addition and understory removal with C. alata addition). Legume addition supported a high proportion of energy flux through herbivorous nematodes, whereas understory vegetation removal supported a high proportion of energy flux through microbivorous nematodes. Less energy fluxes were transferred from basal resources to fungivorous mites and collembolans compared with microbivorous and herbivorous nematodes. The total soil CO2 flux was positively correlated with metabolic rates of herbivorous and omnivorous-predatory nematodes, and energy fluxes through multitrophic groups. Taken together, legume addition and understory vegetation removal modify the patterns of soil CO2 emissions via changing nematode metabolic rates and re-shaping the energetic structure of soil food webs.

Spatiotemporal variations of large wood and river channel morphology in a rapidly degraded reach of an intermittent river

AbstractThe links between rapid channel degradation and related large wood (LW) recruitment and storage are still not precisely understood, especially in aquatic systems with high human and natural pressures such as intermittent rivers in the peri‐Mediterranean region. In this study, by using multidisciplinary research (analysis of satellite images time series, detailed field inventory, and simulated hydrological data), we focused on rapid upstream propagation of channel degradation (i.e., incision and consequent channel widening) in an intermittent Mediterranean river (Evrotas River, southern Greece) as a response to short‐term intensive gravel extraction from the active channel and removal of riparian vegetation in the 2013–2016 period. Subsequently, our objective was to link this channel transformation with the spatiotemporal changes of LW storage in the active channel. We found that short‐term and spatially limited human impact, coupled with high flows, allowed rapid upstream progression (~2 km) of erosion processes (approximately twofold widening of the active channel) during the relatively short 2‐year period (2017–2019). This morphological response accelerated LW recruitment through bank erosion and its subsequent storage in the active channel. Incision and channel widening processes were interrupted in the 2019–2021 period due to the prevalence of relatively low, geomorphologically non‐effective flows. However, the storage of LW in the channel continued to increase as a result of the higher trapping efficiency of the widened channel, a delay between tree death and its final uprooting, or by LW recruitment processes not directly related to flood events. We suggest that freshly recruited LW has the potential to accelerate the establishment of a new channel equilibrium and increase channel heterogeneity through its interaction with flows and sediments.

Rainfall-induced shallow landslides triggered after vegetation removed because of fires: G-XSLIP application to Gioiosa Marea (Sicily, Italy)

The paper analyses how vegetation prevents the triggering of rainfall-induced shallow landslides by using the G-XSLIP platform, which is based on G-SLIP model, i.e., the SLIP model updated with vegetation parameters for root reinforcement and rain interception due to canopy. G-XSLIP is applied to an area in Gioiosa Marea (Sicily, Italy), where on 9th September 2016 shallow landslides occurred, depositing on the state road SS 113. The analyses demonstrate that the triggering of these phenomena is related to the removal of vegetation after summer fires some months before, which decreases computed safety factors by about half.

3D effects of soil-atmosphere interaction on infrastructure slope stability

It has long been established that pore water pressure (pwp) variations affect the stability and serviceability of slopes. Pwp variations may be due to consolidation/swelling processes within soils of low permeability or may be due to seasonal evapotranspiration and precipitation processes. The simultaneous study of such phenomena and of hydro-mechanical coupling in sloping ground requires use of advancednumerical methods. Often, infrastructure slopes are considered in plane strain (two-dimensional) conditions for simplicity and to date this is the case for most numerical analyses considering soil-atmosphere interaction. However, this approach makes it impossible to study the longitudinal extent of a possible slip surface forming following vegetation removal. Three-dimensional, fully-coupled numerical analyses of acut slope were performed herein to study the effect of vegetation clearance on stability and explore numerically ways of implementing effective vegetation management.

Detecting Historical Terrain Anomalies With UAV-LiDAR Data Using Spline-Approximation and Support Vector Machines

The documentation of historical remains and cultural heritage is of great importance to preserve historical knowledge. Many studies use low-resolution airplane-based laser scanning and manual interpretation for this purpose. In this study, a concept to automatically detect terrain anomalies in a historical conflict landscape using high-resolution UAV-LiDAR data was developed. We applied different ground filter algorithms and included a spline-based approximation step in order to improve the removal of low vegetation. Due to the absence of comprehensive labeled training data, a one-class support vector machine algorithm was used in an unsupervised manner in order to automatically detect the terrain anomalies. We applied our approach in a study site with different densities of low vegetation. The morphological ground filter was the most suitable when dense near-ground vegetation is present. However, with the use of the spline-based processing step, all filters used could be significantly improved in terms of the F1-score of the classification results. It increased by up to 42 percentage points in the area with dense low vegetation and by up to 14 percentage points in the area with sparse low vegetation. The completeness (recall) reached maximum values of 0.8 and 1.0, respectively, when taking into account the results leading to the highest F1-score for each filter. Therefore, our concept can support on-site field prospection.

Создание пространственной модели рельефа местности по результатам геодезических измерений для анализа воздействия на окружающую среду в условиях малых карьеров

Mining, especially open pit mining, has a significant impact on the terrain. The article discusses the use of geodetic methods to monitor the process of mining and its possible impact on the environ-ment. The created relief model can be used to design the process of quarry restoration after their closure. The mineral wealth of a country is considered an important factor and is linked to the country's economy. Mineral resources are non-renewable, and their extraction and subsequent processing must take into account the rarity of their occurrence, the level of mining technologies to track spatial changes in mining operations. The main idea of this scientific study is to apply geodetic measurement methods to determine the current scale of mining in a quarry using a 3D terrain model. The paper presents an overview of the technologies used in performing geodetic measurements, as well as processing the measured data to assess the state of the spatial distribution of a quarry in order to determine the impact of mining on the landscape. The purpose of this article is to create a spatial terrain model based on the results of geodetic measurements to analyze the impact on the environment in small open pits. Methods of geodetic observations were used to create a spatial model of the terrain. Digital maps were also created by photogrammetric processing of aerial stereo images and subsequent semi-automatic removal of vegetation and other objects.

A brief review of the effect of wildfires on rockfall occurrence

Wildfires and rockfalls are among the major hazards in forested mountainous regions across Europe. Understanding processes and conditions that lead to rockfalls during and after a wildfire in different geological contexts is, therefore, of great relevance. The increase of rockfalls associated with the occurrence of wildfires is connected to several factors, not only in the detached area but also in the propagation and affected area. Wildfires cause changes in the mechanical properties of rocks and discontinuities as well as the loss of protective capacity from vegetation, complemented by the effect induced by firefighting activities and by extreme temperatures that may deteriorate the installed protective measures. After the occurrence of a wildfire, there is an increase in the frequency and intensity of rockfalls in the burned area, causing a major impact of rockfalls on road networks and inhabited areas. Additionally, the rockfall risk perception is usually increased due to the removal of vegetation by wildfires, exposing both rock blocks and the rock mass. In this review, the main factors that influence the occurrence of rockfalls after a wildfire are briefly reviewed.