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Abstract. This paper aims to assess the spatial variability in the response of CO2 exchange to irradiance across the Arctic tundra during peak season using light response curve (LRC) parameters. This investigation allows us to better understand the future response of Arctic tundra under climatic change. Peak season data were collected during different years (between 1998 and 2010) using the micrometeorological eddy covariance technique from 12 circumpolar Arctic tundra sites, in the range of 64–74° N. The LRCs were generated for 14 days with peak net ecosystem exchange (NEE) using an NEE–irradiance model. Parameters from LRCs represent site-specific traits and characteristics describing the following: (a) NEE at light saturation (Fcsat), (b) dark respiration (Rd), (c) light use efficiency (α), (d) NEE when light is at 1000 μmol m−2 s−1 (Fc1000), (e) potential photosynthesis at light saturation (Psat) and (f) the light compensation point (LCP). Parameterization of LRCs was successful in predicting CO2 flux dynamics across the Arctic tundra. We did not find any trends in LRC parameters across the whole Arctic tundra but there were indications for temperature and latitudinal differences within sub-regions like Russia and Greenland. Together, leaf area index (LAI) and July temperature had a high explanatory power of the variance in assimilation parameters (Fcsat, Fc1000 and Psat, thus illustrating the potential for upscaling CO2 exchange for the whole Arctic tundra. Dark respiration was more variable and less correlated to environmental drivers than were assimilation parameters. This indicates the inherent need to include other parameters such as nutrient availability, substrate quantity and quality in flux monitoring activities.

Les pays en développement, qui contribuent à 90 % de la production aquacole mondiale, sont considérés comme des points chauds du risque climatique mondial. Cependant, aucune étude ne se concentre sur la mesure de la vulnérabilité de l'aquaculture au niveau régional ou infranational aux aléas climatiques ou aux catastrophes. Cette étude a mesuré le niveau de vulnérabilité de l'aquaculture à la variabilité et au changement climatiques dans les 64 districts du Bangladesh en utilisant une approche d'indice de vulnérabilité composite (utilisant 19 indicateurs climatiques, environnementaux et socio-économiques) et un système d'information géographique (SIG). Les résultats révèlent que l'aquaculture dans 12 districts, à savoir Satkhira, Mymensingh, Panchagarh, Lalmonirhat, Nilphamari, Thakurgaon, Sunamganj, Dinajpur, Kurigram, Noakhali, Lakshmipur et Cox' s Bazar, présente une vulnérabilité très élevée (de la vulnérabilité la plus élevée à la plus faible), qui s'explique par leur niveau d'exposition plus élevé, leur niveau de sensibilité modéré et leur niveau de capacité d'adaptation inférieur à modéré. Parmi ceux-ci, 8 districts appartiennent à l'intérieur des terres et 4 districts aux régions côtières du pays. Trois districts, à savoir Dhaka, Chittagong et Bandarban, ont le plus faible niveau de vulnérabilité de l'aquaculture (dans l'ordre de la vulnérabilité la plus faible à la plus élevée) principalement en raison de la très grande capacité d'adaptation et du niveau modéré ou faible de sensibilité et d'exposition. Cette étude ponctuera la vulnérabilité de l'aquaculture continentale et développera et priorisera les actions visant à réduire les impacts climatiques. Los países en desarrollo, que contribuyen con el 90% de la producción acuícola mundial, se consideran puntos críticos de riesgo climático mundial. Sin embargo, ningún estudio se centra en medir la vulnerabilidad de la acuicultura a nivel distrital o subnacional a los peligros o desastres climáticos. Este estudio ha medido el nivel de vulnerabilidad de la acuicultura a la variabilidad y el cambio climático en los 64 distritos de Bangladesh utilizando un enfoque de índice de vulnerabilidad compuesto (utilizando 19 indicadores climáticos, ambientales y socioeconómicos) y un sistema de información geográfica (SIG). Los resultados revelan que la acuicultura en 12 distritos, a saber, Satkhira, Mymensingh, Panchagarh, Lalmonirhat, Nilphamari, Thakurgaon, Sunamganj, Dinajpur, Kurigram, Noakhali, Lakshmipur y Cox 's Bazar, tiene una vulnerabilidad muy alta (en orden de mayor a menor vulnerabilidad), lo que se explica por su mayor nivel de exposición, nivel moderado de sensibilidad y menor a moderado nivel de capacidad de adaptación. Entre estos, 8 distritos pertenecen al interior y 4 distritos a las regiones costeras del país. Tres distritos, a saber, Dhaka, Chittagong y Bandarban, tienen el nivel más bajo de vulnerabilidad de la acuicultura (en orden de menor a mayor vulnerabilidad) principalmente debido a una capacidad de adaptación muy alta y un nivel moderado o bajo de sensibilidad y exposición. Este estudio puntualizará la vulnerabilidad de la acuicultura continental y desarrollará y priorizará acciones para reducir los impactos climáticos. Developing countries, which contribute 90% of global aquaculture production, are considered global climate risk hotspots. However, no study focuses on measuring district- or sub-national-level aquaculture vulnerability to climatic hazards or disasters. This study has measured the level of aquaculture vulnerability to climate variability and change in all 64 districts of Bangladesh using a composite vulnerability index approach (using 19 climatic, environmental and socio-economic indicators) and geographical information system (GIS). The results reveal that aquaculture in 12 districts namely Satkhira, Mymensingh, Panchagarh, Lalmonirhat, Nilphamari, Thakurgaon, Sunamganj, Dinajpur, Kurigram, Noakhali, Lakshmipur, and Cox's Bazar have very high vulnerability (in order of highest to lowest vulnerability), which are explained by their higher level of exposure, moderate level of sensitivity, and lower to moderate level of adaptive capacity. Among these, 8 districts belong to inland and 4 districts to coastal regions of the country. Three districts, namely Dhaka, Chittagong, and Bandarban, have the lowest level of aquaculture vulnerability (in order of lowest to highest vulnerability) mainly because of very high adaptive capacity and moderate or low level of sensitivity and exposure. This study will punctuate the vulnerability of inland aquaculture and develop and prioritize actions to reduce the climatic impacts. تعتبر البلدان النامية، التي تساهم بنسبة 90 ٪ من الإنتاج العالمي لتربية الأحياء المائية، نقاطًا ساخنة لمخاطر المناخ العالمي. ومع ذلك، لا تركز أي دراسة على قياس مدى تأثر الاستزراع المائي على مستوى المنطقة أو المستوى دون الوطني بالمخاطر أو الكوارث المناخية. قاست هذه الدراسة مستوى ضعف تربية الأحياء المائية أمام تقلب المناخ وتغيره في جميع مقاطعات بنغلاديش البالغ عددها 64 مقاطعة باستخدام نهج مؤشر الضعف المركب (باستخدام 19 مؤشرًا مناخيًا وبيئيًا واجتماعيًا واقتصاديًا) ونظام المعلومات الجغرافية (GIS). تكشف النتائج أن الاستزراع المائي في 12 مقاطعة وهي ساتخيرا وميمنسينغ وبانتشاغاره ولالمونيرات ونيلفاماري وثاكورغاون وسونامغانج وديناجبور وكوريغرام ونواخالي ولاكشميبور وكوكس بازار لديهم ضعف شديد للغاية (بالترتيب من الأعلى إلى الأقل ضعفًا)، وهو ما يفسره ارتفاع مستوى تعرضهم ومستوى حساسيتهم المعتدل ومستوى قدرتهم على التكيف من الأقل إلى المعتدل. من بين هذه المناطق، تنتمي 8 مقاطعات إلى المناطق الداخلية و 4 مقاطعات إلى المناطق الساحلية في البلاد. ثلاث مقاطعات، وهي دكا وشيتاغونغ وباندربان، لديها أدنى مستوى من الضعف في تربية الأحياء المائية (من الأدنى إلى الأعلى ضعفًا) ويرجع ذلك أساسًا إلى القدرة العالية جدًا على التكيف والمستوى المعتدل أو المنخفض من الحساسية والتعرض. ستحدد هذه الدراسة مدى ضعف الاستزراع المائي الداخلي وتطوير الإجراءات وترتيب أولوياتها للحد من الآثار المناخية.

Understanding and responding to the rapidly occurring environmental changes in the Arctic over the past few decades require new approaches in science. This includes improved collaborations within the scientific community but also enhanced dialogue between scientists and societal stakeholders, especially with Arctic communities. As a contribution to the Third International Conference on Arctic Research Planning (ICARPIII), the Arctic in Rapid Transition (ART) network held an international workshop in France, in October 2014, in order to discuss high-priority requirements for future Arctic marine and coastal research from an early-career scientists (ECS) perspective. The discussion encompassed a variety of research fields, including topics of oceanographic conditions, sea-ice monitoring, marine biodiversity, land-ocean interactions, and geological reconstructions, as well as law and governance issues. Participants of the workshop strongly agreed on the need to enhance interdisciplinarity in order to collect comprehensive knowledge about the modern and past Arctic Ocean's geo-ecological dynamics. Such knowledge enables improved predictions of Arctic developments and provides the basis for elaborate decision-making on future actions under plausible environmental and climate scenarios in the high northern latitudes. Priority research sheets resulting from the workshop's discussions were distributed during the ICARPIII meetings in April 2015 in Japan, and are publicly available online.

AbstractVampyroteuthis infernalis Chun, 1903, is a widely distributed deepwater cephalopod with unique morphology and phylogenetic position. We assessed its habitat and trophic ecology on a global scale via stable isotope analyses of a unique collection of beaks from 104 specimens from the Atlantic, Pacific and Indian Oceans. Cephalopods typically are active predators occupying a high trophic level (TL) and exhibit an ontogenetic increase in δ15N and TL. Our results, presenting the first global comparison for a deep-sea invertebrate, demonstrate that V. infernalis has an ontogenetic decrease in δ15N and TL, coupled with niche broadening. Juveniles are mobile zooplanktivores, while larger Vampyroteuthis are slow-swimming opportunistic consumers and ingest particulate organic matter. Vampyroteuthis infernalis occupies the same TL (3.0–4.3) over its global range and has a unique niche in deep-sea ecosystems. These traits have enabled the success and abundance of this relict species inhabiting the largest ecological realm on the planet.

AbstractIn many regions across the globe, extreme weather events such as storms have increased in frequency, intensity, and duration due to climate change. Ecological theory predicts that such extreme events should have large impacts on ecosystem structure and function. High winds and precipitation associated with storms can affect lakes via short‐term runoff events from watersheds and physical mixing of the water column. In addition, lakes connected to rivers and streams will also experience flushing due to high flow rates. Although we have a well‐developed understanding of how wind and precipitation events can alter lake physical processes and some aspects of biogeochemical cycling, our mechanistic understanding of the emergent responses of phytoplankton communities is poor. Here we provide a comprehensive synthesis that identifies how storms interact with lake and watershed attributes and their antecedent conditions to generate changes in lake physical and chemical environments. Such changes can restructure phytoplankton communities and their dynamics, as well as result in altered ecological function (e.g., carbon, nutrient and energy cycling) in the short‐ and long‐term. We summarize the current understanding of storm‐induced phytoplankton dynamics, identify knowledge gaps with a systematic review of the literature, and suggest future research directions across a gradient of lake types and environmental conditions.