Edge Zone Research Articles

Tectonic Activities Description in the Ongoing Collision Zone of the Eurasia-Arabia Plates Using 2D Surface Waves Tomography

In order to better understand the regional tectonic activities of the continent-continent ongoing collision-compressed edge zone of the Eurasian-Arabic plates, 2D tomography maps of the Caucasus territory using the Rayleigh waves were generated. The 2D tomography images of this study, illustrate the large variety in surface wave propagation velocity in different complex geologic units of the Caucasus. To draw the 2D tomography maps, we accomplished a 2D-linear inversion procedure on the Rayleigh wave dispersion curves for the periods of 5 to 70 s (depth= ~180 km). To conduct this, local-regional data from ~1300 earthquakes (M≥3.9) recorded by the 49 broadband stations from 1999 to 2018 in a wide area with complicated tectonic units were used. In comparison with results of previous studies in Caucasus, the tomography maps for the long-periods (T= 50-70 s; depth ~180 km) are more influenced by the velocity structure of the uppermost mantle which demonstrate the ultralow and ultrahigh-velocity anomalies. The results for the medium-periods (30≤T≤45 s), the low-velocity zones coincide with areas thought to be correlated with underplating of the lower crust (e.g. shallow LAB), while, the high-velocity zones are usually demonstrating the presence of a normal continental crust over a stable and thick or oceanic-like lid. Short-periods (5≤T≤25 s) are more influenced by the ever-evolving deformations of the geological units, sedimentary basins, volcanic complexes, uplifts, and reveals a low-velocity small zone, on the NW slope of the Aragats volcano (depth= ~7 km), which is different from the results of other studies.

Typologising site-specific features in young industrial landscapes

Young industrial landscapes (YILs), dating roughly from the 1930s to 1970s, are by virtue of their location, size, and partly underused capacity potential new locations for urban redevelopment driven by municipalities and private investors. However, such redevelopment often neglects existing physical characteristics including heritage and ecological potentials. This paper raises awareness and knowledge of these potentials by examining YILs’ spatial characteristics as part of the process of elaborating their future roles as sites for urban transformation. We develop a typo-morphological approach to analyse the physical structure of YILs in the Copenhagen capital area, revealing both general and site-specific qualities relevant for future transformations. We find that YILs’ locations and edge zones hold potential for mediating access between cities and green wedges. Site-specific scenic locations, significant earthworks, plantings, and buildings have potential for reuse and contribute spatial ambience. The paper finally discusses how typo-morphology might be understood from a YIL perspective.

Experimental and numerical investigation of thermal fatigue life in wedge specimens made of Ni-resist D5S cast iron

Thermal fatigue experiments were performed on a single-edge wedge specimen of Ni-resist D5S cast iron to reproduce the conditions to which exhaust manifolds are subjected during service. The leading edge temperature was cycled between 20°C and 850°C, and the temperature distribution on the specimen surface was measured with thermocouples during thermal cycling. Due to the complexity of the loads, a uncoupled thermomechanical computation of the problem was performed using the three-dimensional finite element code ABAQUS to evaluate the temperature, stress and strain distribution over a thermal fatigue specimen. The heat fluxes and forced convection coefficients generated by the thermal fatigue benchmark were optimized in both heating and cooling phases by reverse engineering to reproduce the experimental temperature-time profiles measured by thermocouples on the surface of the specimen. Then, an elastic-viscoplastic tow-layer model was used to simulate the mechanical behavior of the studied material. It was found that the maximum stress value was located in the center of the specimen at the edge of the wedge. This result was confirmed by experimental observations. The crack initiation zone is located in the edge zone and the direction of crack propagation is perpendicular to the edge line toward the thick part of the specimen. The saturation of the main crack propagation near the uniform specimen zone was mainly explained by the rapid decrease of the energy dissipated per cycle.

Effects of geomorphological processes and phytoclimate conditions change on forest vegetation in the Pomeranian Bay coastal zone (Wolin National Park, West Pomerania)

The functioning of plant associations, including forest associations, in the coastal cliff edge zone of the Pomeranian Bay in the Wolin National Park (WNP) is determined by short-term factors related to the dynamics of erosion and denudation processes and long-term phytoclimatic conditions’ changes. The study presents a temporary analysis of the occurrence of sea abrasion and water and aeolian erosion, based on the applied hydrometeorological threshold values. The influence of changes in phytoclimatic conditions on the development and productivity of coastal forests with the dominant species of Fagus sylvatica was also presented. Assessments of spatial susceptibility to erosion of the cliff coast and the existing plant associations were also carried out in conditions of the risk of coast erosion. It was found that 55% of the cliff edge zone of the Pomeranian Bay of the WNP and the forest associations (mainly Luzulo pilosae-Fagetum) occurring there are in the zone of particular risk of increased erosion and denudation processes. In addition, unfavourable trends in changes in phytoclimatic conditions in the 21st century were found, which reflect climate changes unfavourable to the development of beech forests on Wolin Island.

Impacts of initial cooling rate on local frosting characteristics of horizontal cold plate surface with edge effect considered

Considering frosting process in applications usually starts along with cooling stage of the corresponding frosting components, a systematic study on the impacts of the initial cooling rate on the frosting characteristics in an edge zone of a cold plate is conducted. The experimental plate surface temperature, air temperature, relative humidity, and velocity were − 15.0 °C, 20.0 °C, 50%, and 1.5 m/s, respectively. It has been demonstrated that a single row of droplets near the plate edge was significantly larger than the remained droplets due to edge effect. The scope of edge effect on the frosting of cold plate was weakened as the initial cooling rate of cold plate increased. For cases with initial cooling stage, the ratio of the frozen stage period to the entire early frosting stage period increased as the initial cooling rate. Besides, compared to a frosting process without an initial cooling stage, frost thickness decreased by 5.5%, 20.7%, and 32.8% when the initial cooling rates were 1.5, 0.5, and 0.25 °C/s after a 1200-s frosting duration. The results can provide basic data for establishing accurate frosting models and bring insight into delaying frosting in practical applications.

Diet, sex, and genetic predisposition to obesity and type 2 diabetes modulate motor and anxiety-related behaviors in mice, and alter cerebellar gene expression

Obesity and type 2 diabetes (T2D) are serious health problems linked to neurobehavioral alterations. We compared motor function, anxiety-related behavior, and cerebellar gene expression in TALLYHO/Jng (TH), a polygenic model prone to insulin resistance, obesity, and T2D, and normal C57BL/6 J (B6) mice. Male and female mice were weaned onto chow or high fat (HF) diet at 4 weeks of age (wk), and experiments conducted at young (5 wk) and old (14 – 20 wk) ages. In the open field, distance traveled was significantly lower in TH (vs. B6). For old mice, anxiety-like behavior (time in edge zone) was significantly increased for TH (vs B6), females (vs males), and for both ages HF diet (vs chow). In Rota-Rod testing, latency to fall was significantly shorter in TH (vs B6). For young mice, longer latencies to fall were observed for females (vs males) and HF (vs chow). Grip strength in young mice was greater in TH (vs B6), and there was a diet-strain interaction, with TH on HF showing increased strength, whereas B6 on HF showed decreased strength. For older mice, there was a strain-sex interaction, with B6 males (but not TH males) showing increased strength compared to the same strain females. There were significant sex differences in cerebellar mRNA levels, with Tnfα higher, and Glut4 and Irs2 lower in females (vs males). There were significant strain effects for Gfap and Igf1 mRNA levels with lower in TH (vs B6). Altered cerebellar gene expression may contribute to strain differences in coordination and locomotion.

Application of point cloud data to assess edge effects on rainforest structural characteristics in tropical Sumatra, Indonesia

ContextIn forestry, edge zones created by forest degradation and fragmentation are more susceptible to disturbances and extreme weather events. The increase in light regime near the edge can greatly alter forest microclimate and forest structure in the long term. In this context, understanding edge effects and their impact on forest structure could help to identify risks, facilitate forest management decisions or prioritise areas for conservation.ObjectiveIn this paper, we focus on the application of airborne laser scanning (ALS) data to assess the impact of edge effects on forest structural metrics in degraded rainforests in Sumatra, Indonesia. Changes in structural heterogeneity with respect to distance from an edge were also quantified.MethodsWe used 22 ALS structural metrics extracted from 105 plots in secondary forests adjacent to oil palm plantations and analysed the change in canopy structure across edge-to-interior transects. In addition, 91 plots taken from less disturbed areas were used as reference for comparison with the near-to-edge plots.ResultsOur analysis found strong evidence of degradation in the secondary forests studied, with multiple edge interactions resulting in a non-diminishing effect even at long distances from the forest edge. On average, we observed a large decrease of about 40% in all metrics of canopy height and about 25% in some metrics of canopy structure across all distances from an edge when compared to the interior forest conditions. Thus, in our forests, canopy height and structure were more susceptible to edge effects than metrics related to canopy gaps. Finally, the degraded forest in our study exhibited lower structural complexity, both at patch and landscape levels, suggesting that disturbances can greatly alter structural complexity in tropical rainforests.ConclusionOur study confirms the potential of ALS-derived vegetation metrics to study and understand the effects of forest edges and the associated changes in structural complexity over large areas in tropical rainforests. The approach followed here is transferrable to similarly fragmented landscapes in the tropics.

Effects of Climate Change on Chlorophyll a in the Barents Sea: A Long-Term Assessment.

The Arctic climate strongly affects phytoplankton production and biomass through several mechanisms, including warming, sea ice retreat, and global atmospheric processes. In order to detect the climatic changes in phytoplankton biomass, long-term variability of chlorophyll a (Chl-a) was estimated in situ with the changes in the surface sea temperature (SST) and salinity (SSS) in the Barents Sea and adjacent waters during the period of 1984-2021. Spatial differences were detected in SST, SSS, and Chl-a. Chl-a increased parallel to SST in the summer-autumn and spring periods, respectively. Chl-a peaks were found near the ice edge and frontal zones in the spring season, while the highest measures were observed in the coastal regions during the summer seasons. SST and Chl-a demonstrated increasing trends with greater values during 2010-2020. Generalized additive models (GAMs) revealed that SST and Chl-a were positively related with year. Climatic and oceanographic variables explained significant proportions of the Chl-a fluctuations, with six predictors (SST, annual North Atlantic Oscillation index, temperature/salinity anomalies at the Kola Section, and sea ice extent in April and September) being the most important. GAMs showed close associations between increasing Chl-a and a decline in sea ice extent and rising water temperature. Our data may be useful for monitoring the Arctic regions during the era of global changes and provide a basis for future research on factors driving phytoplankton assemblages and primary productivity in the Barents Sea.

Wind loading characteristics and roof zoning of solar arrays mounted on flat-roofed tall buildings

Effects of building height (24, 48, 72, and 96 m) and panel tilt angle on wind loads of solar arrays on sharp roofs were investigated through wind tunnel testing. The largest mean and negative peak module force coefficients among all modules and wind angles tended to decrease as building height increased. This is attributed to that approaching flows tend to separate from roof edges rather than building sides of low-rise buildings. Moreover, building height exerted a more significant influence on the largest mean and negative peak module force coefficients among all wind angles on modules at roof corners than those at roof edges and centers. Roof zoning of solar arrays was conducted using the k-means algorithm. The roof zoning scheme helps to balance the design cost and structural safety of rooftop solar arrays. Roofs can be divided into three categories based on k-means clustering analysis, i.e., corner, edge, and interior zones. Besides, regression analysis of mean and negative peak loads with building height at various roof zones was conducted. This study provides recommendations for design wind loads on solar arrays mounted on roofs with different heights.

Self-sensing of cutting temperature in single point diamond turning by a boron-doped diamond tool

Cutting temperature is important in single point diamond turning. However, the challenge of measuring temperature in single point diamond turning is locating a sensor at the cutting edge during machining. This paper presents a tool system having a capability of measuring cutting temperature in diamond turning by the tool itself without any additional temperature sensors. A diamond tool was doped with boron via high temperature and high pressure treatment, by which the tool becomes a P-type semiconductor and thus have a thermal-sensitive characteristic for indicating the cutting temperature at the cutting edge zone during diamond turning processes.

Population Density and Stability of Breeding Birds in English Oak Woodland Over a 32-Year Period in Relation to Habitat Structure and Edges

Long-term breeding bird censuses in Białowieża National Park (BNP), north-east Poland, have revealed rather low densities of birds and high community stability which may be features of near-natural forest conditions. This paper reports on a long-term census of breeding birds in 50 ha of oak woodland in central England which contained both managed and undisturbed areas. New information is provided on breeding bird density and its spatial variation within English mature broadleaved woodland to address two questions: Under what circumstances are English woods likely to support higher densities than those occurring in BNP? Is there evidence that population and community stability is lower in English woodland? The overall bird density was lower than in the BNP oak-hornbeam stands, at the scale of both the whole study area and the undisturbed stands. Densities of three of the five dominant species (Cyanistes caeruleus, Parus major, Troglodytes troglodytes) were lower in BNP, Fringilla coelebs was higher, while Erithacus rubecula was similar. Within the undisturbed stands, densities of seven of 12 species, including T. troglodytes, were similar to those in BNP, two were considerably higher (C. caeruleus, P. major) and one much lower (F. coelebs). Selection of the external woodland edge by several species resulted in relatively high overall densities in the edge zone. The broad composition of the bird community remained fairly stable with the exception of declines in tropical migrants and increases in shrub layer nesters. Temporal abundance patterns of species showed much individuality. Trends of several species appeared to be driven by changes in habitat structure. However, the same species remained numerically dominant or characteristic of the wood throughout the study period. This suggests there was a core of resilient species, much as proposed for BNP. Although caution is needed in drawing conclusions from a single site, with the exception of a small number of species, in recent decades there is unlikely to have been a general pattern of higher densities of birds in English woodland than in BNP. However, some English woods with highly complex vegetation structures, or a high proportion of edge habitat, do have exceptionally high densities (> 100 territories/10 ha).

Methane migration, sea ice melting and spatial distribution of chlorophyll-a in the Barents Sea

The paper considers the theoretical and practical aspects of the relationship between the processes of sea ice melting and methane migration, and their influence on the distribution of chlorophyll-a concentration as an indicator of productivity and the level of quantitative development of the phytoplankton community at the spring stage of the succession cycle. In the spring of 2018 and 2019 the thermohaline characteristics of waters and the content of chlorophyll-a in the Barents Sea were studied. The area of work covered both areas with the most probable release of methane from near-bottom gas hydrates, as well as background areas, where the presence of methane hydrates is unlikely. In 2018, the phytoplankton community of the study area was in the spring flowering stage. In the area of the most probable influence of methane, the average concentrations of chlorophyll-a were approximately 2 times higher than in the background area. High concentrations of the pigment were associated with the thawed layer, which may indicate the release of methane from the ice. In 2019, low concentrations of chlorophyll-a in the edge zone excluded the stage of spring flowering of the phytoplankton community, which did not allow us to trace the possible effect of the release of methane hydrates on the concentration of chlorophyll-a.

Extraction, Separation, Antitumor Effect, and Mechanism of Alkaloids in Sophora alopecuroides: A Review

Malignant tumors pose a serious threat to human health, reducing quality of life. Natural antitumor drugs play a vital role in the treatment of cancer. Sophora alopecuroides, a traditional Chinese medicine not a part of the Chinese Pharmacopoeia, grows in the arid desert and edge zone of grassland. Previous studies have extensively investigated the antitumor effects of S. alopecuroides and its major alkaloids. Of these, aloperine, matrine, oxymatrine, sophoridine, and sophocarpine have received the most attention. In recent years, a variety of extraction and separation methods have been applied to the study of the alkaloids of Sophora alopecuroides, which has greatly promoted the study of the chemical constituents and pharmacological activities of the plant. S. alopecuroides has been shown to impede cancer cell growth, induce cell cycle arrest, enhance apoptosis and cellular differentiation, and impede cancer metastasis and invasion. Several mechanisms have been proposed for modulating cancer signaling and molecular pathways or targets based on multitudinous studies in various types of cancerous cells. This review provides an in-depth overview of the antitumor effects of S. alopecuroides and the potential targets of 12 alkaloids in S. alopecuroides via a pharmacophore mapping approach and offers a scientific basis for the further exploration of the mechanism related to the antitumor effects of this plant.

Theoretical modelling of the effect of thermal delamination of an asphalt concrete pavement from a rigid foundation of a road or bridge

In the practice of road construction, one of the most common phenomena accompanied by delamination, subsequent cracking and destruction of the asphalt concrete pavement on a rigid (cement concrete or metal) base of a road or bridge is the effect of concentration of shear thermal stresses between the pavement and the base in the edge zones of the structure. They are caused by the fact that, as a rule, the coefficients of linear thermal expansion of the phases of the system have different values, which contributes to the occurrence of incompatible shrinkages and expansions in them. Under conditions of frequent temperature changes in heterogeneous asphalt concrete structures with thermomechanical incompatibility of their components, these effects can contribute to their accelerated aging. At the same time, with the thermomechanical compatibility of materials, a more favorable distribution of internal stresses of thermal and mechanical origin is achieved, which excludes premature degradation of the strength of the contacting phases and the entire system as a whole. Using the methods of strengthof materials and the finite element method, it has been established that under the conditions of a change in the temperature of the system during its seasonal and daily fluctuations, shear stresses are subjected to the highest concentration. They are localized in the edge zone of the plane of contact between the layers and increase with an increase in the thickness and modulus of elasticity of the upper layer. These stresses are the main reason for the occurrence of plastic deformations in these zones and subsequent delamination of the structure in them. It is proposed to reduce the concentration and level of generated high-gradient shear stresses by reducing the thickness of the asphalt concrete layer in these areas.

An experimental study on the dynamic frosting characteristics on the edge zone of a horizontal copper plate under forced convection

To retard the negative effects of frosting, it is necessary to better understand the frosting mechanism on cold surfaces. In this study, a systematical study on the dynamic frosting characteristics on the edge zone of a horizontal copper plate under forced convection was conducted. The results showed that the air velocity effect and edge effect on droplet condensation, frozen and frost layer growth characteristics were significant. The duration of droplet condensation stage decreased from 365 to 113 s with a decrease of 69.0% when air velocity increased from 0.5 to 2.5 m/s. Besides, the average freezing wave propagation velocity for Region I (an area where a row of water droplets closest to plate edge) was significantly larger than that for Region II (the remained area). As a result, the duration of droplet frozen stage for Region I was much shorter than that for Region II. Accordingly, frost layer amount for Region I was notably larger than that for Region II. Besides, the frost surface roughness for Region I increased as air velocity increased at the early frosting stage, but decreased as air velocity increased at the later frosting stage. The general turning point for frost surface roughness at 1.5 m/s surpassed the value at 0.5 m/s was around 21.4 × 10−6 m at 390 s, and that between 2.5 m/s and 1.5 m/s was around 30.3 × 10−6 m at 450 s. This study can help to establish a better relationship among different frosting stages, and better understand the plate edge effect on frosting.

Transitional rock glaciers at sea level in northern Norway

Abstract. Rock glaciers are geomorphological expressions of permafrost. Close to sea level in northernmost Norway, in the subarctic Nordkinn peninsula, we have observed several rock glaciers that appear to be active now or were active in the recent past. Active rock glaciers at this elevation have never before been described in Fennoscandia, and they are outside the climatic limits of present-day permafrost according to models. In this study, we have investigated whether or not these rock glaciers are active under the current climate situation. We made detailed geomorphological maps of three rock glacier areas in Nordkinn and investigated the regional ground dynamics using synthetic aperture radar interferometry (InSAR). One of the rock glaciers, namely the Ivarsfjorden rock glacier, was investigated in more detail by combining observations of vertical and horizontal changes from optical images acquired by airborne and terrestrial sensors and terrestrial laser scans (TLSs). The subsurface of the same rock glacier was investigated using a combination of electrical resistivity tomography (ERT) and refraction seismic tomography (RST). We also measured ground surface temperatures between 2016 and 2020, complemented by investigations using an infrared thermal camera, and a multi-decadal climatic analysis. We mapped the rock glaciers in the innermost parts of Store and Lille Skogfjorden as relict, while the more active ones are in the mouths of both fjords, fed by active talus in the upper slopes. Several of the rock glaciers cross over both the Younger Dryas shoreline (25 m a.s.l.) and the Early to Mid-Holocene shoreline at 13 m a.s.l. Both InSAR and optical remote sensing observations reveal low yearly movement rates (centimetres to millimetres per year). The ERT and RST suggest that there is no longer permafrost and ground ice in the rock glacier, while temperature observations on the front slope indicate freezing conditions also in summer. Based on the in situ temperature measurements and the interpolated regional temperature data, we show that the mean annual air temperature (MAAT) of the region has risen by 2 ∘C since the late 19th century to about 1.5 ∘C in the last decade. MAATs below 0 ∘C 100–150 years ago suggest that new rock glacier lobes may have formed at the end of the Little Ice Age (LIA). These combined results indicate that the Nordkinn rock glaciers are transitioning from active to relict stages. The study shows that transitional rock glaciers are still affected by creep, rock falls, snow avalanches, etc., and are not entirely dynamically dead features. Our contrasting results concerning permafrost presence and rock glacier activity show the importance of a multi-methodological approach when investigating slope processes in the edge zones of permafrost influence.

Mitigating the risk of wind damage at the forest landscape level by using stand neighbourhood and terrain elevation information in forest planning

Abstract Wind damage and the bark beetle outbreaks associated with it are major threats to non-declining, long-term wood production in boreal forests. We studied whether the risk of wind damage in a forested landscape could be decreased by using stand neighbourhood information in conjunction with terrain elevation information. A reference management plan minimized the differences in canopy height at stand boundaries and did not utilize information on the topography of the terrain, overlooking the possibility that the risk of windthrow may depend on the elevation of the terrain. Alternative management plans were developed by using four different weighting schemes when minimizing differences in canopy height at stand boundaries: (1) no weight (reference); (2) mean terrain elevation at the stand boundary; (3) deviation of the mean elevation of the boundary from the mean elevation of the terrain within a 100-m radius and (4) multipliers that described the effect of topography on wind speed at the stand boundary. For each management plan, we calculated the total number of at-risk trees and the total area of vulnerable stand edge. These statistics were based on the calculated critical wind speeds needed to uproot trees in stand edge zones. Minimization of the weighted mean of canopy height differences between adjacent stands resulted in homogeneous landscapes in terms of canopy height. Continuous cover management was often preferred instead of rotation management due to smaller canopy height differences between adjacent stands and its economical superiority. The best weighting scheme for calculating the mean canopy height difference between adjacent stands was the deviation between the mean elevation of the boundary and the mean elevation of the terrain within 100 m of the boundary. However, the differences between the weighting schemes were small. It was found that reasonably simple methods, based on a digital terrain model, a stand map, and the canopy heights of stands, could be used in forest planning to minimize the risk of wind damage. Validation against actual wind damages is required to assess the reliability of the results and to further develop the methodology presented.

Real-time distributed dispatch strategy for distribution transformer supply zone cluster based on cloud-edge collaboration architecture

Aiming at the problem of long-timescale prediction deviation in the distribution network, a fast regulation strategy of cloud-edge coordination based on an intelligent transformer supply zones edge consistency algorithm is proposed. The cloud makes the global initial optimal allocation to the edge transformer supply zone clusters, and then the cluster makes the secondary collaborative optimal allocation to the edge zones. A fast power interaction model within a cluster based on a consensus algorithm is established, and the micro-increase rate of dispatching cost is used as the consistency variable so that the cluster adjustment amount is optimally allocated to each transformer supply zone, and the total dispatch cost of all transformer supply zones is minimized. The simulation example verifies the effectiveness of the cloud-edge collaborative fast control strategy based on the intelligent station cluster edge consensus algorithm in this article.

Analiza holoceńskich zmian środowiskowych w rynnie glacjalnej pomiędzy jeziorem Gopło a Jeziorem Szarlejskim i ich wpływ na osadnictwo w okresie od neolitu do nowożytności na podstawie badań osadów jeziornych oraz danych archeologicznych i historycznych

The aim of the study is to analyze environmental changes in the area between Gopło and Szarlejskie Lakes. The Noteć River flows through this area, connecting both lakes. The lakes could have been connected and functioned as Wielkie Gopło. Geological reconnaissance was based on five boreholes drilled with a soil auger. The samples were subjected to granulometric analyses and the content of organic matter and calcium carbonate was determined. Eight samples were radiocarbon-dated using the AMS method. Recognition of the valley bottom settlement was done through spatial analysis using six Archaeological Project Records sheets. The results of the research allowed separating three phases of the area development: lake, bog and lake again. The beginning of the last lake development phase and its evolution have not been precisely dated and require research. Archaeological data demonstrate the poor settlement use of the glacial trough. Throughout the prehistoric period, settlement was concentrated at an altitude of 80–85 m above sea level, in the edge zone of trough. This means that the area was marshy and inaccessible for settlement. Drainage, regulation works in the Noteć river basin and industrial activities, led to the lowering of the groundwater level and weakened the lake’s recharge. Consequently, the lake disappeared from the studied area.

Edges as hotspots and drivers of forest cover change in a tropical landscape

Forest cover changes are influenced by socioeconomic and biophysical dynamics. However, the relative importance of both social and biophysical factors to forest loss and gain remains in debate. Previous research has focused mainly in identifying determinants of deforestation, while less is known regarding forest regrowth, especially in tropical forests. Here we investigated the spatial pattern and determinants of forest cover changes within a landscape which is representative of the biophysical and socioeconomic conditions found in the Atlantic Forest, and also presents an exceptional conservation value within this global biodiversity hotspot. Events of deforestation and regrowth were identified by comparing land cover maps from aerial images taken in 1975 and 2010. We controlled the spatial autocorrelation among events and used a machine learning algorithm and a selection model approach to build linear models explaining forest loss and gain. Main determinants of both forest loss and gain were biophysical factors, although some of they may also reflect socioeconomic underlying processes. Distance from Strictly Protected Areas (SPAs) was the single socioeconomic determinant important to forest change, in loss events. Both deforestation and forest regrowth were strongly associated with forest edges. Deforestation occurred more intensively on concave or flat areas, low solar radiation conditions, near forests, and far from SPAs. Diversely, forest regrowth occurred mostly in high slopes, low elevation areas, high solar radiation and near to forest edges. Our findings reinforce the important role of topography and protected area on forest change, and highlight edge zones are “hotspots” of forest cover dynamics. .