Climate and Vegetation of the Interior Lowlands of Southern Baffin Island : Long-term Stability at the Low Arctic Limit

The interior of southern Baffin Island between 64 N and 68 N latitude is a mainly lowland area over 50 000 km² in extent, containing two large lakes (Amadjuak and Nettilling) and numerous smaller lakes and ponds. This area is important as summer range for caribou and a variety of birds, and there is evidence for a human presence as early as 3000 B.P. Field studies between 1984 and 1988 and the operation of climatic autostations from 1987 to 1995 revealed a warm summer climate and cold winters. There is a locally rich and diverse vegetation, including Betula glandulosa and other species that are indicative of the low arctic bioclimatic zone and mark the present northern limit of that zone in the eastern Canadian Arctic. Air photos and Landsat imagery were used to map vegetation beyond the field areas, leading to an estimate of 46% of the land area in continuous vegetation (tundra) of some type and 15% with shrub and heath elements. Palynology of sediment cores taken from Nettilling Lake permitted extrapolation from present bioclimatic conditions to 4750 years B.P. Betula and therefore elements of a low arctic vegetation association appear to have been present in the area during most of that period, indicating a local bioclimatic system that has been relatively stable under regional variations of climate.La région intérieure du sud de la terre de Baffin située entre le 64° et le 68° de latit. N. est essentiellement une zone de basses-terres s'étendant sur plus de 50 000 km², qui renferme deux grands lacs (Amadjuak et Nettilling) et de nombreux petits lacs et étangs. Cette région est importante en tant que territoire estival du caribou et d'une diversité d'oiseaux, et on y a découvert des preuves attestant une présence humaine dès 3000 BP. Des études sur le terrain menées entre 1984 et 1988 et l'activité de stations climatologiques automatisées de 1987 à 1995 ont révélé un climat d'été tempéré et d'hiver froid. La végétation locale est riche et diversifiée et comprend Betula glandulosa ainsi que d'autres espèces typiques d'une zone bioclimatique du Bas-Arctique et marquant la limite septentrionale actuelle de cette zone dans l'Arctique canadien oriental. Des clichés aériens et des images du satellite Landsat ont servi à cartographier la végétation au-delà des zones d'étude sur le terrain, ce qui a amené à une estimation de 46 p. cent de la zone possédant un couvert végétal continu (toundra) d'une certaine sorte et 15 p. cent possédant des composants d'arbrisseaux et de bruyère. La palynologie de carottes de sédiments provenant du lac Nettilling a permis d'extrapoler les conditions bioclimatiques depuis la période actuelle jusqu'à 4750 ans BP. Il semble que Betula et par conséquent des composants d'une association végétale du Bas-Arctique ont été présents dans la région pendant la plus grande partie de cette période, ce qui révèle l'existence d'un système bioclimatique relativement stable à l'intérieur de variations climatiques régionales

Climate and Vegetation of the Interior Lowlands of Southern Baffin Island: Long-term Stability at the Low Arctic Limit

The interior of southern Baffin Island between 64 N and 68 N latitude is a mainly lowland area over 50 000 km² in extent, containing two large lakes (Amadjuak and Nettilling) and numerous smaller lakes and ponds. This area is important as summer range for caribou and a variety of birds, and there is evidence for a human presence as early as 3000 B.P. Field studies between 1984 and 1988 and the operation of climatic autostations from 1987 to 1995 revealed a warm summer climate and cold winters. There is a locally rich and diverse vegetation, including Betula glandulosa and other species that are indicative of the low arctic bioclimatic zone and mark the present northern limit of that zone in the eastern Canadian Arctic. Air photos and Landsat imagery were used to map vegetation beyond the field areas, leading to an estimate of 46% of the land area in continuous vegetation (tundra) of some type and 15% with shrub and heath elements. Palynology of sediment cores taken from Nettilling Lake permitted extrapolation from present bioclimatic conditions to 4750 years B.P. Betula and therefore elements of a low arctic vegetation association appear to have been present in the area during most of that period, indicating a local bioclimatic system that has been relatively stable under regional variations of climate

Cloud-native Seascape Mapping of Mozambique’s Quirimbas National Park with Sentinel-2

The lack of detailed spatial information on coastal resources, notably shallow water coral reefs and associated benthic habitats, impedes our ability to protect and manage them in the face of global climate change and anthropogenic impacts. Here, we develop a semi‐automated workflow in the cloud that uses freely available Sentinel‐2 data from the European Space Agency (ESA) Copernicus programme to derive information on near‐shore coral reef habitats in the Quirimbas National Park (QNP), a recently declared biosphere reserve in northern Mozambique. We use an end‐to‐end cloud‐based framework within the Google Earth Engine cloud geospatial platform to process imagery from raw pixels to cloud‐free composites which are corrected for glint and surface artefacts, water column and derived estimated depth and then classified into four benthic habitats. Using independent training and validation data, we apply three supervised classification algorithms: random forests (RF), support vector machine (SVM) and classification and regression trees (CART). Our results show that random forests are the most accurate supervised algorithm with over 82% overall accuracy. We mapped over 105 000 ha of shallow water habitat inside the protected area, of which 18% are dominated by coral and hardbottom; 27.5% are seagrass and submerged aquatic vegetation and another 23.4% are soft and sandy substrates, and the remaining area is optically deep water. We employ satellite‐derived bathymetry to assess slope, bathymetric position, rugosity and underwater topography of these habitats. Finally, a spectral unmixing model provides further sub‐pixel–level information of habitats with the potential to monitor changes over time. This effort provides the first, consistent and repeatable and also scalable coastal information system for an east African tropical marine protected area, which hosts shallow‐water ecosystems which are of great significance to local communities and building resilience towards climate change

Fisheries and biodiversity benefits of using static versus dynamic models for designing marine reserve networks

Marine reserves are widely used to manage for the potentially conflicting objectives of conserving biodiversity and improving fisheries. The fisheries and conservation benefits of alternative reserve designs would ideally be assessed using dynamic models, which consider spillover of fish and larvae to fished areas, and the displacement of fishers to unprotected sites. In practice, however, decisions about the location of marine reserves generally rely on cheaper and faster static models. Static models analyze only spatial patterns in habitats, and typically assume fisheries profits are reduced by the amount that was generated in areas designated as reserves. To help determine the benefits of developing dynamic fisheries models, we assessed how well static models estimate costs of reserve systems to fisheries and how outcomes from reserves designed using either static or dynamic models differ. We tested these questions in two case studies, the network of marine protected areas in southern California, USA and the proposed Tun Mustapha Marine Park in Malaysia. Static models could either under or over-estimate the cost of reserve plans to fisheries, depending on the relative importance of fisher movement and larval dispersal dynamics. Despite the inaccuracy of static models for estimating costs, reserves designed using static models were similar to those designed with dynamic models if fisheries were well managed; or larval dispersal networks were simple. If larval networks were complex or there was overfishing, dynamic models generated substantially different reserve networks from static models, which improved conservation outcomes by up to 10% and fishing profits by up 20%. The time-scale of management was also important, because only dynamic models accounted for larval dispersal, so could find reserves that maximized the long-term benefits of larval spillover. Our case studies provide quantitative support for the assertion that static models can be useful for planning marine reserves for short-term objectives in well managed fisheries, but are not reliable for evaluating the relative costs of reserves to fisheries