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International audience; In recent decades, climate change has been faster in various parts of the world. Within species, to counter rapid climatechanges shift of geographical area, individuals’ plastic responses or populations’ genetic adaptation might occur. The sub-Antarctic islands are subject to one of the most rapid climate changes on earth, with already visible impacts on nativevegetation. Such might be the case of Lyallia kerguelensis a cushion plant strictly endemic to the Kerguelen Islands. In L.kerguelensis, necrotic parts were observed in cushions these last decades and possibly related to water stress. We analysedmorphological variability of L. kerguelensis, including necrosis extent, across 19 populations spanning a wide range ofenvironments across the Kerguelen Islands. Inter-population variations in the cushion surface area, shape and compactnesswere well explained by topography, degree of wind exposure, slope aspect, proportions of coarse sand and bare soil, andgeographical distance between populations. All these variables are related to wind intensity and water availability. Moreover,in cushions with less than 10% necrosis in surface area, necrosis extent was positively correlated to soil sodium. Sodiumavailability might reduce the plant’s capacity for osmotic adjustment in face of other abiotic stresses, such as water stress. Weconclude that cushion morphology may have the capacity to adjust to environmental variation, including aspects of climatechange, but that cushion necrosis may be accelerated in the driest and most saline environments.

The paper describes the development of predictive equations of windthrow for five tree species based on remote sensing of wind-affected stands in southwestern New Brunswick (NB). The data characterises forest conditions before, during and after the passing of extratropical cyclone Arthur, July 4–5, 2014. The five-variable logistic function developed for balsam fir (bF) was validated against remote-sensing-acquired windthrow data for bF-stands affected by the Christmas Mountains windthrow event of November 7, 1994. In general, the prediction of windthrow in the area agreed fairly well with the windthrow sites identified by photogrammetry. The occurrence of windthrow in the Christmas Mountains was prominent in areas with shallow soils and prone to localised accelerations in mean and turbulent airflow. The windthrow function for bF was subsequently used to examine the future impact of windthrow under two climate scenarios (RCP’s 4.5 and 8.5) and species response to local changes anticipated with global climate change, particularly with respect to growing degree-days and soil moisture. Under climate change, future windthrow in bF stands (2006–2100) is projected to be modified as the species withdraws from the high-elevation areas and NB as a whole, as the climate progressively warms and precipitation increases, causing the growing environment of bF to deteriorate.

The aim of this article is to show geomorphological mapping of remote Antarctic locations using images taken by a fixed-wing unmanned aerial vehicle (UAV) during the Beyond Visual Line of Sight (BVLOS) operations. We mapped landform assemblages developed in forelands of Ecology Glacier (EGF), Sphinx Glacier (SGF) and Baranowski Glacier (BGF) in Antarctic Specially Protected Area No. 128 (ASPA 128) on King George Island (South Shetland Islands) and inferred about glacial dynamics. The orthophoto and digital elevation model allowed for geomorphological mapping of glacial forelands, including (i) glacial depositional landforms, (ii) fluvial and fluvioglacial landforms, (iii) littoral and lacustrine landforms, (iv) bodies of water, and (v) other. The largest area is occupied by ground moraine and glacial lagoons on EGF and BGF. The most profound features of EGF are the large latero-frontal moraine ridges from Little Ice Age and the first half of the 20th century. Large areas of ground moraine, frequently fluted and marked with large recessional moraine ridges, dominate on SGF. A significant percentage of bedrock outcrops and end moraine complexes characterize BGF. The landform assemblages are typical for discontinuous fast ice flow of tidewater glaciers over a deformable bed. It is inferred that ice flow velocity decreased as a result of recession from the sea coast, resulting in a significant decrease in the length of ice cliffs and decrease in calving rate. Image acquisition during the fixed-wing UAV BVLOS operation proved to be a very robust technique in harsh polar conditions of King George Island.

20 Pags.- 6 Figs. The definitive version is available at: https://link.springer.com/journal/10933, Shallow lakes in semiarid regions experience frequent water level fluctuations. Each long-lasting episode of water-level lowering leaves behind abandoned littoral forms and deposits whose identification and mapping is hampered by their smooth relief. Given the difficulty of recognising these possible relict forms using traditional geomorphological techniques, two sources of information were employed in the present work: high resolution (1:15,000) aerial photographs and a digital terrain model (DTM) generated from LiDAR data. The improved definition of surface elevation enhanced the quality of geomorphological mapping as well as the accurate delineation of subtle geoforms. The method was applied to Gallocanta Lake, a highly fluctuating shallow lake 14 km2 in area and less than 3 m deep located in a mountainous semiarid area of NE Spain. As a result, a sequence of relict coastal features (RCF) with high lateral continuity has been identified around the lakebed. These include well-preserved spits with recurved hooks, counter-spits, bays closed by barrier islands, beach ridges, deltas and cliffs. The highly precise LiDAR-derived topographic maps suggest a much greater extension of the lacustrine environment during the Late Pleistocene, reaching at least 51 km2 of water surface and about 13 m of depth above the present lake bottom. The method presented in this paper generates very detailed palaeogeographical maps that are particularly useful for reconstructing lake changes in semiarid environments as a function of climate change., This work has been funded by the Spanish Ministry of Economy and Competitiveness (MINECO) under the project PCIN-2014-106 and by the Spanish Research Council (CSIC) under the project i-COOP-2016SU0015.

This paper illustrates a land consumption map for Italy (year 2017) at a scale 1:1,300,000, and the assessment of its changes (2012–2017). We define land consumption as the replacement of a non-artificial land cover to an artificial land cover, both permanent and no-permanent. The maps are a 10 m spatial resolution raster, produced by photointerpretation of very high resolution images and semiautomatic classification of high resolution remote sensing images. An overall accuracy of 97.7% for the map of 2012 and of 99.66% for the map of 2017 was obtained. The results suggest that the method proposed is appropriate to detect land consumption, both for the urban densification and for the sprawling phenomena, from national to local level. Furthermore, because of the high spatial resolution and the classification scheme adopted, it is suitable for an effective monitoring system, compared to other existing classification systems or monitoring programs.

Recent increases in urbanization and tourism threaten the viability of UNESCO world heritage sites across the globe. The Angkor world heritage site located in southern Cambodia is now facing such a challenge. Over the past two decades, Angkor has seen over 300,000% growth in international tourist arrivals, which has led to uncontrolled development of the nearby city of Siem Reap. This study uses remote sensing and GIS to comprehend the process of urban expansion during the past 14 years, and has applied the CA-Markov model to predict future urban expansion. This paper analyzes the urban pressure on the Angkor site at different scales. The results reveal that the urban area of Siem Reap city increased from 28.23 km2 in 2004 to 73.56 km2 in 2017, an increase of 160%. Urban growth mainly represented a transit-oriented pattern of expansion, and it was also observed that land surfaces, such as arable land, forests, and grasslands, were transformed into urban residential land. The total constructed land area in the core and buffer zones increased by 12.99 km2 from 2004 to 2017, and 72% of the total increase was in the buffer zone. It is predicted that the built-up area in Siem Reap is expected to cover 135.09 km2 by 2025 and 159.14 km2 by 2030. The number of monuments that are most likely be affected by urban expansion is expected to increase from 9 in 2017 to 14 in 2025 and 17 in 2030. The urban area in Siem Reap has increased dramatically over the past decade and monuments continue to be decimated by urban expansion. This paper urges closer attention and urgent actions to minimize the urban pressure on the Angkor site in the future.

International audience; When the Amazonian rain forest is cut to create pasture, some of the original vegetal species survive clearing, even expressing their ability to invade agro-systems. It is true of the babassu palm, which can be considered, paradoxically, a natural resource by the "Interstate Movement of Babassu Fruit Breaker Women" or as native weed by land owners-farmers. To manage potential conflict of land uses, we study here the current density of this palm tree in different habitats, based on a combination of field data and remote sensing data. Firstly, we checked that the field survey methodology (i.e., counting free-trunk palm trees over 20 cm in circumference) provides density values compatible with those stemming from satellite images interpretation. We can see then that, a PA-Benfica Brazilian territory revealed an average density of the babassu lower in pastures (2.86 ind/ha) than in the dense forest (4.72 ind/ha) from which they originate and than in fallow land (4.31 ind/ ha). We analyze in detail density data repartition in three habitats and we discuss results from the literature on the density of this palm tree versus its resilience at different developmental stages after forest clearing, depending on anthropogenic -or not- factors, including solar radiation, fire, weeding, clear cutting, burying fruit, and competition with forage grass. All these results can be exploited for the design of future management plans for the babassu palm and we think that the linked methodology and interdisciplinary approach can be extended to others palms and trees species in similar problematic issues.

Land cover identification and area quantification are key aspects in determining support payments to farmers under the European Common Agricultural Policy. Agricultural land is monitored using the Land Parcel Identification System and visual image interpretation. However, shadows covering reference parcel boundaries can hinder effective delineation. Visual interpretation of shadows is labor intensive and subjective, while automated methods give reproducible results. In this paper we compare shadow detection on satellite imagery obtained by expert photointerpretation to a proposed automated, data-driven method. The latter automated method is a thresholding approach employing both panchromatic and multispectral imagery, where the former has a finer spatial resolution than the latter. Thresholds are determined from automatically generated training data using a risk-based approach. Comparison of the total shadow area per scene showed that more pixels were labelled as shadow by the automatic procedure than by visual interpretation. However, the union of shadow area independently identified by twelve experts on a subscene was larger than the automatically determined shadow area. The limited intersection of the shadow areas identified by the experts demonstrated that experts strongly disagreed in their interpretations. The shadow area labelled by the automated method was in between the intersection and the union of the areas interpreted by experts. Furthermore, the automated shadow detection method is reproducible and reduces the interpretation effort and skill required.

Pour assister les politiques publiques d’aménagement du territoire et de gestion de l’environnement sur le littoral, le suivi de l’étalement urbain et la caractérisation de l’évolution des tissus urbanisés constituent un préalable indispensable. Dans cette perspective, la production de données d’occupation du sol à grande échelle est une nécessité et de nombreuses initiatives de la recherche et des pouvoirs publics ont été engagées à cet effet. En prenant pour terrain d’application le littoral de la Côte bleue, en Provence, cet article rend compte d’une expérimentation de cartographie de l’occupation du sol à grande échelle, basée sur une nomenclature urbaine à 44 classes compatible Corine Land Cover. Produite avec quatre millésimes (1998, 2003, 2008 et 2011), la base de données résultante permet la caractérisation de l’évolution récente de l’urbanisation à une échelle fine. L’étalement urbain et la densification urbaine peuvent alors être analysés avec précision. La transformation des territoires artificialisés apparaît ainsi bien supérieure à la production de nouveaux tissus urbanisés par étalement. Mais malgré cette densification, l’urbanisation pavillonnaire demeure majoritaire. To assist spatial planning and environmental management policies in coastal areas, the monitoring of urban sprawl and the characterization of the evolution of built-up areas are essential prerequisites. In this perspective, the production of land use data sets on a large-scale is necessary and many governmental and research initiatives have been engaged for this purpose. Taking as a case study the coastal zone of the Côte bleue, in Provence, this paper reports on an experiment of land use mapping on a large-scale, based on a classification made of 44 urban classes compliant with Corine Land Cover. Available with four versions (1998, 2003, 2008 and 2011), the resulting database allows an accurate characterization of the recent evolution of the urbanization. Urban sprawl and urban densification can be studied using spatial analysis. Thus, the transformation of artificial areas appears much higher than urban sprawl. However, urban areas composed of single houses still prevail.

International audience; Les données statistiques de l'Inventaire forestier national, provenant des observations et mesures réalisées sur le terrain, sont bien connues des utilisateurs. Il n'en est pas encore de même pour les données cartographiques qui recèlent pourtant des informations précieuses. Issues de la numérisation des contours des types de formation végétale délimités en photo-interprétation, elles permettent une caractérisation géographique des forêts françaises. Cette approche se révèle très utile, notamment pour l'évaluation et le suivi de certains indicateurs de gestion durable. La publication des "Indicateurs de gestion durable des forêts françaises" parue en 1995 (Ministère de l'Agriculture et de la Pêche - DERF, 1995) contenait déjà quelques indicateurs cartographiques mais qui ne concernaient que les 59 départements, disposant à l'époque d'une cartographie numérisée. La couverture cartographique de l'IFN étant aujourd'hui complète, la dernière édition des "Indicateurs" (MAP-DERF, 2000) permet de réaliser un premier état des lieux de la situation sur l'ensemble du territoire métropolitain, en compilant des cartes ayant des dates de référence variant de 1980 à 1996.

A study was made of the spectral characteristics of sudden changes occurring in a 40x40 km forest in S. Finland in 1984-87 using satellite scanner images (Landsat Thematic Mapper and Spot images and spectroradiometer measurements). Scots pine (Pinus sylvestris) and Norway spruce (Picea abies) were the most common tree species. The changes were (1) clear felling, (2) selective thinning, (3) site preparation on clear felled areas, (4) weeding of deciduous shrubs and/or thinning of conifer seedling regeneration, (5) damage caused by the fungus Gremmeniella abietina and (6) deciduous shrub growth in regeneration areas. A computer model of spectral characteristics was developed and compared with the empirical data. G. abietina damage increased the reflectance in the visible part of the light spectrum and decreased the reflectance in the rear infrared part. Near infrared reflectance was reduced after thinning. A system for automated monitoring of changes is presented.

The central Platte River in Nebraska, USA, has undergone substantial channel narrowing since basin settlement in the mid-nineteenth century. Many researchers have studied the causes of channel narrowing and its implications for endangered species that use wide, shallow channel segments with barren sandbars. As a result, changes in metrics such as unvegetated channel width have been studied. With few exceptions, these measures are estimated from aerial imagery without mention of error in relation to actual channel conditions and/or investigator bias. This issue is not unique to central Platte River studies, as a general lack of commentary is apparent regarding the direct comparison of channel planform characteristics interpreted from aerial imagery relative to those measured in the field. Here we present a case study where data collected by the Platte River Recovery Implementation Program was used to make multiple comparisons using three years of field-measured unvegetated channel widths and those photointerpreted from aerial imagery. Widths were interpreted by three investigators, who identified similar widths in almost all cases. Photointerpretation from imagery collected during the fall resulted in unvegetated width estimates that were more consistent with field measurments than estimates derived using imagery collected in June. Differences were attributed to three main factors: (1) influences of discharge on photointerpretation of unvegetated channel width; (2) increases in vegetative cover throughout the growing season; and (3) resolution of imagery. Most importantly, we concluded that photointerpretation of unvegetated widths from imagery collected during high flows can result in significant over estimation of unvegetated channel width.