Trees are among the longest-living organisms. They are sensitive to extreme climatic events and document the effects of environmental changes in form of structural modifications of their tissues. These modifications represent an integrated signal of complex biological responses enforced by the environment. For example, temporal change in stem increment integrates multiple information of tree performance, and wood anatomical traits may be altered by climatic extremes or environmental stress. Recent developments in preparative tools and computational image analysis enable to quantify changes in wood anatomical features, like vessel density or vessel size. Thus, impacts on their functioning can be related to climatic forcing factors. Similarly, new developments in monitoring (cambial) phenology and mechanistic modelling are enlightening the interrelationships between environmental factors, wood formation and tree performance and mortality. Quantitative wood anatomy is a reliable indicator of drought occurrence during the growing season, and therefore has been studied intensively in recent years. The variability in wood anatomy not only alters the biological and hydraulic functioning of a tree, but may also influence the technological properties of wood, with substantial impacts in forestry. On a larger scale, alterations of sapwood and phloem area and their ratios to other functional traits provide measures to detect changes in a tree’s life functions, and increasing risk of drought-induced mortality with possible impacts on hydrological processes and species composition of plant communities. Genetic variability within and across populations is assumed to be crucial for species survival in an unpredictable future world. The magnitude of genetic variation and heritability of adaptive traits might define the ability to adapt to climate change. Is there a relation between genetic variability and resilience to climate change? Is it possible to link genetic expression and climate change to obtain deeper knowledge of functional genetics? To derive precise estimates of genetic determinism it is important to define adaptive traits in wood properties and on a whole-tree scale. Understanding the mechanisms ruling these processes is fundamental to assess the impact of extreme climate events on forest ecosystems, and to provide realistic scenarios of tree responses to changing climates. Wood is also a major carbon sink with a long-term residence, impacting the global carbon cycle. How well do we understand the link between wood growth dynamics, wood carbon allocation and the global carbon cycle? Papers contribution to this Research Topic will cover a wide range of ecosystems. However, special relevance will be given to Mediterranean-type areas. These involve coastal regions of four continents, making Mediterranean-type ecosystems extremely interesting for investigating the potential impacts of global change on growth and for studying responses of woody plants under extreme environmental conditions. For example, the ongoing trend towards warmer temperatures and reduced precipitation can increase the susceptibility to fire and pests. The EU-funded COST Action STREeSS (Studying Tree Responses to extreme Events: a SynthesiS) addresses such crucial tree biological and forest ecological issues by providing a collection of important methodological and scientific insights, about the current state of knowledge, and by opinions for future research needs.

Climate extremes often imply significant impacts on human and natural systems, and these extreme events are anticipated to be among the potentially most harmful consequences of a changing climate. However, while extreme event impacts are increasingly recognized, methodologies to address such impacts and the degree of our understanding and prediction capabilities vary widely among different sectors and disciplines. Moreover, traditional climate extreme indices and large-scale multi-model intercomparisons that are used for future projections of extreme events and associated impacts often fall short in capturing the full complexity of impact systems. Climate Extremes and Their Implications for Impact and Risk Assessment describes challenges, opportunities and methodologies for the analysis of the impacts of climate extremes across various sectors to support their impact and risk assessment. It thereby also facilitates cross-sectoral and cross-disciplinary discussions and exchange among climate and impact scientists. The sectors covered include agriculture, terrestrial ecosystems, human health, transport, conflict, and more broadly covering the human-environment nexus. The book concludes with an outlook on the need for more transdisciplinary work and international collaboration between scientists and practitioners to address emergent risks and extreme events towards risk reduction and strengthened societal resilience.

Changes in atmospheric carbon dioxide concentrations and global climate conditions have altered photosynthesis and plant respiration across both geologic and contemporary time scales. Understanding climate change effects on plant carbon dynamics is critical for predicting plant responses to future growing conditions. Furthermore, demand for biofuel, fibre and food production is rapidly increasing with the ever-expanding global human population, and our ability to meet these demands is exacerbated by climate change. This volume integrates physiological, ecological, and evolutionary perspectives on photosynthesis and respiration responses to climate change. We explore this topic in the context of modeling plant responses to climate, including physiological mechanisms that constrain carbon assimilation and the potential for plants to acclimate to rising carbon dioxide concentration, warming temperatures and drought. Additional chapters contrast climate change responses in natural and agricultural ecosystems, where differences in climate sensitivity between different photosynthetic pathways can influence community and ecosystem processes. Evolutionary studies over past and current time scales provide further insight into evolutionary changes in photosynthetic traits, the emergence of novel plant strategies, and the potential for rapid evolutionary responses to future climate conditions. Finally, we discuss novel approaches to engineering photosynthesis and photorespiration to improve plant productivity for the future. The overall goals for this volume are to highlight recent advances in photosynthesis and respiration research, and to identify key challenges to understanding and scaling plant physiological responses to climate change. The integrated perspectives and broad scope of research make this volume an excellent resource for both students and researchers in many areas of plant science, including plant physiology, ecology, evolution, climate change, and biotechnology. For this volume, 37 experts contributed chapters that span modeling, empirical, and applied research on photosynthesis and respiration responses to climate change. Authors represent the following seven countries: Australia (6); Canada (9), England (5), Germany (2), Spain (3), and the United States (12).

Dendrochronologists have long estimated the impact of climate on tree-ring growth by empirical-statistical methods. The use of the model is illustrated with examples from widely differing environments, and possible future directions for model development and application are discussed. As forests are the main carbon sink on land, the results are of great importance for all global change studies.

Extreme weather and climate events, interacting with exposed and vulnerable human and natural systems, can lead to disasters. This Special Report explores the social as well as physical dimensions of weather- and climate-related disasters, considering opportunities for managing risks at local to international scales. SREX was approved and accepted by the Intergovernmental Panel on Climate Change (IPCC) on 18 November 2011 in Kampala, Uganda.

As climate has warmed over recent years, a new pattern of more frequent and more intense weather events has unfolded across the globe. Climate models simulate such changes in extreme events, and some of the reasons for the changes are well understood. Warming increases the likelihood of extremely hot days and nights, favors increased atmospheric moisture that may result in more frequent heavy rainfall and snowfall, and leads to evaporation that can exacerbate droughts. Even with evidence of these broad trends, scientists cautioned in the past that individual weather events couldn't be attributed to climate change. Now, with advances in understanding the climate science behind extreme events and the science of extreme event attribution, such blanket statements may not be accurate. The relatively young science of extreme event attribution seeks to tease out the influence of human-cause climate change from other factors, such as natural sources of variability like El Niño, as contributors to individual extreme events. Event attribution can answer questions about how much climate change influenced the probability or intensity of a specific type of weather event. As event attribution capabilities improve, they could help inform choices about assessing and managing risk, and in guiding climate adaptation strategies. This report examines the current state of science of extreme weather attribution, and identifies ways to move the science forward to improve attribution capabilities.

At present the study of functional and ecological wood anatomy enjoys a vigorous renaissance and plays a pivotal role in plant and ecosystem biology, plant evolution, and global change research. This book contains a selection of papers presented at the successful meetings of the International Association of Wood Anatomists and the Cost-Action STReESS (Studying Tree Responses to extreme Events: a Synthesis) held in Naples in April 2013. Four review papers address (1) the hydraulic architecture of the earliest land plants, (2) the general phenomenon of axial conduit tapering in trees, (3) the hydraulic and biomechanical optimization in one of the most important plantation grown tree species, Norway Spruce, and (4) cellular and subcellular changes in the cambium in response to environmental factors. Three papers review or introduce new tools to observe the 3-D structure and functioning of wood, and novel tools for quantitative image analysis in tree ring series. Finally, five papers report original research on environmental effects on wood structure, including studies on plastic responses in European beech, effects of fire or late summer rains on Mediterranean Aleppo Pine, and the potential for using arctic shrubs or tropical deciduous trees in dendrochronological and climatological studies. Reprinted from IAWA Journal 34 (4), 2013.