Responses To Climate Change In The Cold Biomes
Download Responses To Climate Change In The Cold Biomes PDF/ePub or read online books in Mobi eBooks. Click Download or Read Online button to get Responses To Climate Change In The Cold Biomes book now. This website allows unlimited access to, at the time of writing, more than 1.5 million titles, including hundreds of thousands of titles in various foreign languages.
Responses to Climate Change in the Cold Biomes
Author: Hans J. De Boeck
language: en
Publisher: Frontiers Media SA
Release Date: 2019-06-05
Climate change is thought to be especially relevant to ecosystems in the cold biomes. Observed warming has been higher in cold climates through various positive feedbacks, especially declining snow and ice cover, and climate projections indicate further rapid warming in the decades to come. Temperature change can have profound impacts in cold biome ecosystems, either directly in terms of impacts on physiology or growing season length, or indirectly via changes in nutrient cycling. The regions focused on here are the (sub)arctic and the (sub)alpine areas, both characterized by short growing seasons and low annual temperatures, but with different radiation environments depending on latitude. Climate change can have impacts in all seasons. Increased spring temperatures can accelerate snowmelt, leading to an earlier onset of the growing season, while warmer summers may stimulate primary productivity through temperatures closer to metabolic optima and/or increased mineralization rates. Winter warming can lead to the vegetation being damaged because of exposure to harsh frost without insulating snow cover. In all of this, concurrent changes in precipitation also play an important role: increased snowfall can buffer warming-induced advances in snowmelt, a higher ratio of rain to snow can greatly accelerate snowmelt in winter and spring, and summer drought may reverse growth-stimulation by warming directly (drought stress) or indirectly (e.g. impaired nutrient uptake). Micro-climate is crucial in these systems and requires particular attention as it can vary widely across the landscape, creating different growing environments in the space of a few meters or even less. Interest in cold region responses to climate change does not only arise from the fact that they harbor unique ecosystems that may be endangered, but also because they store large amounts of carbon that may be released under climate change. However, research is challenging because of the remoteness of many of these areas and the harsh conditions during much of the year. In spite of this, some studies have been carried out over an extensive period, spanning decades and yielding information on for example plant community reorganization (including invasions), and changes in phenology above- and/or belowground. Other studies focus on shorter term effects, such as impacts of heat waves, late frosts or other anomalous weather, including longer term (after-) effects that may differ drastically from other regions because of the short growing season in cold climates. Ultimately, models are used to predict future changes in vegetation along latitudinal or elevational gradients, although phenology and microclimatic variation may pose particular challenges. Contributions to this Research Topic focus on climate change, encompassing both changes in the mean (gradual warming) and variability (heat waves, altered precipitation distribution) in cold biomes. The Topic contains reports on observed changes or events, but also research making use of experimentally imposed environmental changes. The focus is varied, including phenology, physiology, soil and vegetation science and biogeochemistry, with the aim of providing a comprehensive overview of observed and expected responses to climate change in cold biome ecosystems.
Microbial Responses to Environmental Changes
Advances in next generation sequencing technologies, omics, and bioinformatics are revealing a tremendous and unsuspected diversity of microbes, both at a compositional and functional level. Moreover, the expansion of ecological concepts into microbial ecology has greatly advanced our comprehension of the role microbes play in the functioning of ecosystems across a wide range of biomes. Super-imposed on this new information about microbes, their functions and how they are organized, environmental gradients are changing rapidly, largely driven by direct and indirect human activities. In the context of global change, understanding the mechanisms that shape microbial communities is pivotal to predict microbial responses to novel selective forces and their implications at the local as well as global scale. One of the main features of microbial communities is their ability to react to changes in the environment. Thus, many studies have reported changes in the performance and composition of communities along environmental gradients. However, the mechanisms underlying these responses remain unclear. It is assumed that the response of microbes to changes in the environment is mediated by a complex combination of shifts in the physiological properties, single-cell activities, or composition of communities: it may occur by means of physiological adjustments of the taxa present in a community or selecting towards more tolerant/better adapted phylotypes. Knowing whether certain factors trigger one, many, or all mechanisms would greatly increase confidence in predictions of future microbial composition and processes. This Research Topic brings together studies that applied the latest molecular techniques for studying microbial composition and functioning and integrated ecological, biogeochemical and/or modeling approaches to provide a comprehensive and mechanistic perspective of the responses of micro-organisms to environmental changes. This Research Topic presents new findings on environmental parameters influencing microbial communities, the type and magnitude of response and differences in the response among microbial groups, and which collectively deepen our current understanding and knowledge of the underlying mechanisms of microbial structural and functional responses to environmental changes and gradients in both aquatic and terrestrial ecosystems. The body of work has, furthermore, identified many challenges and questions that yet remain to be addressed and new perspectives to follow up on.
Responses of Northern U.S. Forests to Environmental Change
Author: Robert A. Mickler
language: en
Publisher: Springer Science & Business Media
Release Date: 2012-12-06
In the Global Change Research Act of 1990, "global change" is defined as "changes in the global environment (including alterations in climate, land productivity, oceans or other water resources, atmospheric chemistry, and ecological systems) that may alter the capacity of the Earth to sustain life. " For the purposes of this book, we interpret the definition of global change broadly to include physical and chemical environmental changes that are likely to affect the productivity and health of forest ecosystems over the long term. Important environmental changes in the Northern United States include steadily increasing atmospheric carbon dioxide, tropospheric ozone, wet and dry deposition of nitrogen and sulfur compounds, acidic precipitation and clouds, and climate variability. These environmental factors interact in complex ways to affect plant physiological functions and soil processes in the context of forest landscapes derived from centuries of intensive land use and natural disturbances. Research in the North has begun to unravel some key questions about how environmental changes will impact the productivity and health of forest ecosystems, species distributions and abundance, and associations of people and forests. Initial research sponsored by the USDA Forest Service under the United States Global Change Research Program (USGCRP) was focused on basic process-level understanding of tree species and forest v VI Preface ecosystem responses to environmental stress. Chemical pollution stresses received equal emphasis with climate change concerns.