Spatio-temporal Variability of Wildfires and Their Climate Drivers from Continental to Global Scale

Spatio-temporal Variability of Wildfires and Their Climate Drivers from Continental to Global Scale PDF Author: Maria Zubkova
Publisher:
ISBN:
Category : Climatology
Languages : en
Pages : 254

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Book Description
Fire is a natural component of most ecosystems, and it has effects on vegetation, soil, water, atmospheric composition, and human well-being. Despite increasing interest in interdisciplinary approaches to analyzing global fire activity and the growing body of wildfire research, there are still many gaps and uncertainties in our knowledge. Some come from the lack of understanding of the complex relationships between fire and climate, which is additionally entangled by the strong influence of human activity. This dissertation evaluates the role of environmental context in determining the spatial patterns of fire activity on a large scale. First, the fire-climate relationship was analyzed in terms of the most studied and understood fire metric - the amount of burned area - which was shown to have changed significantly in the last two decades. Most of the recent changes were attributed to the decrease in fire activity in Africa, where the amount of burned area declined by 18.5% between 2002 and 2016. Although humans have a long history of modifying fire activity in Africa, climate factors directly related to biomass productivity and aridity explained about 70% of the changes in burned area in natural land covers, providing evidence that increased terrestrial moisture during 2002-2016 facilitated declines in fire activity in Africa. These results illustrate the strong influence of climate on fire activity and in particular proxy for fuel productivity and fuel dryness. Based on these findings, a framework was proposed for defining and classifying fire regimes (a range of characteristics that describe the fire events in the space-time window). This framework was based on the assumption that fuel productivity and desiccation are the two fundamental processes that limit fire activity, and their combination sets important boundary conditions for key fire regime metrics on a large scale. By testing this approach in Africa and Australia, it was evident that while the amount of rainfall is an important driver of fire through controlling fuel productivity, a variation of rainfall within and between years drives fuel dryness and fire activity especially in Australia, a continent with a strong precipitation gradient. Additionally, among continents, fire metrics vary substantially even within the same biome. These results informed an additional global analysis, where 26 distinct fire regions were identified, not including areas where fire activity is highly modified by human activity. This approach did not only discriminate between regions with significantly different fire activity across a number of biomes but also identified how fire attributes vary under different conditions and what factors constrain modern fire regimes. These findings should help to improve our understanding of fire complexity and its interaction and feedbacks with climate which is essential to assess the potential effect of global climate change on fire regimes.

Spatio-temporal Variability of Wildfires and Their Climate Drivers from Continental to Global Scale

Spatio-temporal Variability of Wildfires and Their Climate Drivers from Continental to Global Scale PDF Author: Maria Zubkova
Publisher:
ISBN:
Category : Climatology
Languages : en
Pages : 254

Get Book Here

Book Description
Fire is a natural component of most ecosystems, and it has effects on vegetation, soil, water, atmospheric composition, and human well-being. Despite increasing interest in interdisciplinary approaches to analyzing global fire activity and the growing body of wildfire research, there are still many gaps and uncertainties in our knowledge. Some come from the lack of understanding of the complex relationships between fire and climate, which is additionally entangled by the strong influence of human activity. This dissertation evaluates the role of environmental context in determining the spatial patterns of fire activity on a large scale. First, the fire-climate relationship was analyzed in terms of the most studied and understood fire metric - the amount of burned area - which was shown to have changed significantly in the last two decades. Most of the recent changes were attributed to the decrease in fire activity in Africa, where the amount of burned area declined by 18.5% between 2002 and 2016. Although humans have a long history of modifying fire activity in Africa, climate factors directly related to biomass productivity and aridity explained about 70% of the changes in burned area in natural land covers, providing evidence that increased terrestrial moisture during 2002-2016 facilitated declines in fire activity in Africa. These results illustrate the strong influence of climate on fire activity and in particular proxy for fuel productivity and fuel dryness. Based on these findings, a framework was proposed for defining and classifying fire regimes (a range of characteristics that describe the fire events in the space-time window). This framework was based on the assumption that fuel productivity and desiccation are the two fundamental processes that limit fire activity, and their combination sets important boundary conditions for key fire regime metrics on a large scale. By testing this approach in Africa and Australia, it was evident that while the amount of rainfall is an important driver of fire through controlling fuel productivity, a variation of rainfall within and between years drives fuel dryness and fire activity especially in Australia, a continent with a strong precipitation gradient. Additionally, among continents, fire metrics vary substantially even within the same biome. These results informed an additional global analysis, where 26 distinct fire regions were identified, not including areas where fire activity is highly modified by human activity. This approach did not only discriminate between regions with significantly different fire activity across a number of biomes but also identified how fire attributes vary under different conditions and what factors constrain modern fire regimes. These findings should help to improve our understanding of fire complexity and its interaction and feedbacks with climate which is essential to assess the potential effect of global climate change on fire regimes.

Fire Regimes: Spatial and Temporal Variability and Their Effects on Forests

Fire Regimes: Spatial and Temporal Variability and Their Effects on Forests PDF Author: Yves Bergeron
Publisher: MDPI
ISBN: 3038423904
Category : Science
Languages : en
Pages : 433

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Book Description
This book is a printed edition of the Special Issue "Fire Regimes: Spatial and Temporal Variability and Their Effects on Forests" that was published in Forests

Advances in Earth Observation of Global Change

Advances in Earth Observation of Global Change PDF Author: Emilio Chuvieco
Publisher: Springer Science & Business Media
ISBN: 9048190851
Category : Science
Languages : en
Pages : 286

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Book Description
Global Change studies are increasingly being considered a vital source of information to understand the Earth Environment, in particular in the framework of human-induced climate change and land use transformation. Satellite Earth Observing systems provide a unique tool to monitor those changes. While the range of applications and innovative techniques is constantly increasing, this book provides a summary of key case studies where satellite data offer critical information to understand the causes and effects of those environmental changes, minimizing their negative impacts. This book will be of interest to researchers and practitioners in the field of remote sensing, geographical information, meteorology and environmental sciences. Also scientists and graduate up to post-graduate level students in environmental science will find valuable information in this book.

Fire and Climatic Change in Temperate Ecosystems of the Western Americas

Fire and Climatic Change in Temperate Ecosystems of the Western Americas PDF Author: Thomas T. Veblen
Publisher: Springer Science & Business Media
ISBN: 038721710X
Category : Science
Languages : en
Pages : 456

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Book Description
Both fire and climatic variability have monumental impacts on the dynamics of temperate ecosystems. These impacts can sometimes be extreme or devastating as seen in recent El Nino/La Nina cycles and in uncontrolled fire occurrences. This volume brings together research conducted in western North and South America, areas of a great deal of collaborative work on the influence of people and climate change on fire regimes. In order to give perspective to patterns of change over time, it emphasizes the integration of paleoecological studies with studies of modern ecosystems. Data from a range of spatial scales, from individual plants to communities and ecosystems to landscape and regional levels, are included. Contributions come from fire ecology, paleoecology, biogeography, paleoclimatology, landscape and ecosystem ecology, ecological modeling, forest management, plant community ecology and plant morphology. The book gives a synthetic overview of methods, data and simulation models for evaluating fire regime processes in forests, shrublands and woodlands and assembles case studies of fire, climate and land use histories. The unique approach of this book gives researchers the benefits of a north-south comparison as well as the integration of paleoecological histories, current ecosystem dynamics and modeling of future changes.

Implications of Climate Change Variability on Large Fires Across Spatiotemporal Scales in Sagebrush-steppe

Implications of Climate Change Variability on Large Fires Across Spatiotemporal Scales in Sagebrush-steppe PDF Author: Andréa L. Kuchy
Publisher:
ISBN:
Category : Dissertations, Academic
Languages : en
Pages : 228

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Book Description


Changing Climates, Earth Systems and Society

Changing Climates, Earth Systems and Society PDF Author: John Dodson
Publisher: Springer Science & Business Media
ISBN: 9048187168
Category : Science
Languages : en
Pages : 255

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Book Description
The International Year of Planet Earth (IYPE) was established as a means of raising worldwide public and political awareness of the vast, though frequently under-used, potential the Earth Sciences possess for improving the quality of life of the peoples of the world and safeguarding Earth’s rich and diverse environments. The International Year project was jointly initiated in 2000 by the International Union of Geological Sciences (IUGS) and the Earth Science Division of the United Nations Educational, Scienti?c and Cultural Organisation (UNESCO). IUGS, which is a Non-Governmental Organisation, and UNESCO, an Inter-Governmental Organisation, already shared a long record of productive cooperation in the na- ral sciences and their application to societal problems, including the International Geoscience Programme (IGCP) now in its fourth decade. With its main goals of raising public awareness of, and enhancing research in the Earth sciences on a global scale in both the developed and less-developed countries of the world, two operational programmes were demanded. In 2002 and 2003, the Series Editors together with Dr. Ted Nield and Dr. Henk Schalke (all four being core members of the Management Team at that time) drew up outlines of a Science and an Outreach Programme. In 2005, following the UN proclamation of 2008 as the United Nations International Year of Planet Earth, the “Year” grew into a triennium (2007–2009).

Fire Regimes

Fire Regimes PDF Author: Yves Bergeron
Publisher:
ISBN: 9783038423911
Category : Electronic book
Languages : en
Pages :

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Book Description


Thriving on Our Changing Planet: A Decadal Strategy for Earth Observation from Space

Thriving on Our Changing Planet: A Decadal Strategy for Earth Observation from Space PDF Author: National Academies of Sciences, Engineering, and Medicine
Publisher: National Academies Press
ISBN: 0309492432
Category : Science
Languages : en
Pages : 29

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Book Description
We live on a dynamic Earth shaped by both natural processes and the impacts of humans on their environment. It is in our collective interest to observe and understand our planet, and to predict future behavior to the extent possible, in order to effectively manage resources, successfully respond to threats from natural and human-induced environmental change, and capitalize on the opportunities â€" social, economic, security, and more â€" that such knowledge can bring. By continuously monitoring and exploring Earth, developing a deep understanding of its evolving behavior, and characterizing the processes that shape and reshape the environment in which we live, we not only advance knowledge and basic discovery about our planet, but we further develop the foundation upon which benefits to society are built. Thriving on Our Changing Planet: A Decadal Strategy for Earth Observation from Space (National Academies Press, 2018) provides detailed guidance on how relevant federal agencies can ensure that the United States receives the maximum benefit from its investments in Earth observations from space, while operating within realistic cost constraints. This short booklet, designed to be accessible to the general public, provides a summary of the key ideas and recommendations from the full decadal survey report.

Quantitative Methods for Conservation Biology

Quantitative Methods for Conservation Biology PDF Author: Scott Ferson
Publisher: Springer Science & Business Media
ISBN: 0387954864
Category : Nature
Languages : en
Pages : 334

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Book Description
Reviews the quantitative tools used in the study of subjects such as biodiversity, resource management and endangered species preservation. Topics covered include population viability analysis, population dynamics, metapopulation models, estimating timing of extinctions, quasi-extinction and more.

Toward a Better Understanding of Boreal Forest Fires and Their Role in the Climate System

Toward a Better Understanding of Boreal Forest Fires and Their Role in the Climate System PDF Author: Brendan Morris Rogers
Publisher:
ISBN: 9781303810312
Category :
Languages : en
Pages : 202

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Book Description
Large areas of boreal forest in North America and Eurasia are frequently disturbed by wildfire. These fires alter ecosystem structure and function and affect climate through various biophysical and biogeochemical pathways. Fire-related forcings, however, are highly uncertain, can be opposite in sign, and depend on fire behavior as mediated by meteorology and intrinsic ecosystem properties. Our current understanding of large-scale fire dynamics is inadequate for fully characterizing their role in the climate system. This is particularly pertinent given the sensitivity of high latitudes and the large projected increases in fire frequencies during the 21st century. My dissertation aims to better characterize the controls on and feedbacks from boreal fires so that we may properly account for them in global change projections and potentially mitigate the impacts. I first quantified landscape-scale fire carbon emissions from a 2010 burn in Alaska using field measurements and fine-scale (30 m) remote sensing imagery. Accurate maps of fire emissions are needed to validate larger-scale models and quantify regional carbon fluxes, but are currently lacking due to spatial scaling issues. Here I show that by accounting for plot-level heterogeneity and species effects on spectral signatures, emission models can be generated from non-linear correlations between the differenced Normalized Burn Ratio (dNBR) and field data. Belowground combustion was quantified from soil cores and scaled to the site-level using spruce adventitious root heights. Species-specific allometric equations and visual estimates were used to characterize aboveground carbon losses. Results indicated that fire-wide combustion (1.98 ± 0.19 kg C m−2) was substantially lower than that in the core burning area (2.67 ± 0.24 kg C m−2) and sites (2.88 ± 0.23 kg C m−2) because of lower-severity patches and unburned islands. These areas constitute a significant fraction of burn perimeters in Alaska but are generally not accounted for in regional-scale estimates. This approach may be suitable for other fires in the region. In addition to the positive forcing from carbon emissions, forest fires in boreal North America exert a cooling effect due to relatively large increases in spring albedo from canopy destruction and tree fall. Although this forcing has been characterized at local and regional scales, its climate impacts have not been assessed. I simulated the continental-scale climate footprint of this cooling under various burning scenarios. Forest composition was characterized using a stochastic model of fire occurrence, historical fire data from national inventories, and succession trajectories derived from moderate-scale remote sensing (500 m). When coupled to an Earth system model, younger vegetation from increased burning cooled the high-latitude atmosphere, primarily in the winter and spring, with noticeable feedbacks from the ocean and sea ice. Results from multiple scenarios suggested that a doubling of burn area could cool the surface by 0.23 ±0.09°C across boreal North America during winter and spring months (December through May). This has the potential to provide a negative feedback to winter warming across the domain on the order of 3 - 5% for a doubling, and 14 - 23% for a quadrupling, of burn area. Maximum cooling occurred in the areas of greatest burning and between February and April, reaching feedback potentials of up to 60%. Fire dynamics have been studied much less extensively in boreal Eurasia despite the region containing roughly 2/3rds of the world's boreal forests and displaying unique patterns of fire behavior. I used over a decade of satellite imagery to characterize variations in circumpolar fire behavior, immediate impacts, and longer-term responses. Compared to boreal North America, Eurasian fires were 58 ± 31% less likely to be crown fires, combusted 36 ± 5% less live vegetation, and caused 42 ± 5% less tree mortality. Eurasian fires also generated a 69 ± 9% smaller surface shortwave forcing during the initial post-fire decade, suggesting a near-neutral net climate forcing. Current global fire models were unable to capture the continental differences. I demonstrate that fire weather cannot explain the divergent fire dynamics and climate feedbacks. The primary drivers are shown to be species-level adaptations to fire, making this a preeminent example of species effects on continental-scale carbon and energy exchange.