Understanding Northern Latitude Vegetation Greening and Browning


Book Description

Vegetation change has been observed across Arctic and boreal regions. Studies have often documented large-scale greening trends, but they have also identified areas of browning or shifts between greening and browning over varying spatial extents and time periods. At the same time, though, there are large portions of these ecosystems that have not exhibited measurable trends in greening or browning. These findings have fueled many questions about the drivers of vegetation dynamics, how trends are measured, and potential implications of vegetation change at local to global scales. In December 2018, the National Academies of Sciences, Engineering, and Medicine, convened a workshop to discuss opportunities to improve understanding of greening and browning trends and drivers and the implications of these vegetation changes. The discussions included a close look at many of the methodological approaches used to evaluate greening and browning, as well as exploration of newer technologies that may help advance the science. This publication summarizes the presentations and discussions from the workshop.




Disentangling Climate and Disturbance Effects on Regional Vegetation Greening Trends


Book Description

Productivity of northern latitude forests is an important driver of the terrestrial carbon cycle and is already responding to climate change. Studies of the satellite-derived Normalized Difference Vegetation Index (NDVI) for northern latitudes indicate recent changes in plant productivity. These detected greening and browning trends are often attributed to a lengthening of the growing season from warming temperatures. Yet, disturbance-recovery dynamics are strong drivers of productivity and can mask direct effects of climate change. Here, we analyze 1-km resolution NDVI data from 1989 to 2014 for the northern latitude forests of the Greater Yellowstone Ecosystem for changes in plant productivity to address the following questions: (1) To what degree has greening taken place in the GYE over the past three decades? and (2) What is the relative importance of disturbance and climate in explaining NDVI trends? We found that the spatial extents of statistically significant productivity trends were limited to local greening and browning areas. Disturbance history, predominately fire disturbance, was a major driver of these detected NDVI trends. After accounting for fire-, insect-, and human-caused disturbances, increasing productivity trends remained. Productivity of northern latitude forests is generally considered temperature-limited; yet, we found that precipitation was a key driver of greening in the GYE.




Ecosystem Collapse and Climate Change


Book Description

Human-driven greenhouse emissions are increasing the velocity of climate change and the frequency and intensity of climate extremes far above historical levels. These changes, along with other human-perturbations, are setting the conditions for more rapid and abrupt ecosystem dynamics and collapse. This book presents new evidence on the rapid emergence of ecosystem collapse in response to the progression of anthropogenic climate change dynamics that are expected to intensify as the climate continues to warm. Discussing implications for biodiversity conservation, the chapters provide examples of such dynamics globally covering polar and boreal ecosystems, temperate and semi-arid ecosystems, as well as tropical and temperate coastal ecosystems. Given its scope, the volume appeals to scientists in the fields of general ecology, terrestrial and coastal ecology, climate change impacts, and biodiversity conservation.




Analysis of Climate Variability


Book Description

EUROPEAN SCHOOl OF CLiMATOlOGY AND NATURAL HAZARDS The training of scientific and technical personnel and the development of highly qualified scientists are, and have always been, among the important concerns of the European Commission. Advanced training is an important requirement for the implementation of a common EU policy in science and technology. The European School of Climatology and Natural Hazards was started as apart of the training and education activities of the European Programme on Climatology and Natural Hazards (EPOCH), and is continued under the subsequent research programme (ENVIRONMENT 1990-1994). The school consists of annual courses on specialised subjects within re search in climatology and natural hazards, and is open to graduating, grad uate and post graduate students in these fields. Each of the courses is organized in cooperation with a European Institu tion involved in the current research programme, and is aimed at giving to the students formal lectures and participation in informal discussions with leading researchers. The present volume is based on the lectures given at the course held on the island of Elba from the 30th October to the 6th of November 1993 on Statistical Analysis of Climate Variability. It features selected and extended presentations, and represents an important contribution to advanced studies in climate statistical analysis, supplementing more traditional texts. I trust that all those involved in research related to climate change and climate variability will appreciate this work and will benefit from the com prehensive and state-of-the-art information it provides.




Arctic Hydrology, Permafrost and Ecosystems


Book Description

This book provides a comprehensive, up-to-date assessment of the key terrestrial components of the Arctic system, i.e., its hydrology, permafrost, and ecology, drawing on the latest research results from across the circumpolar regions. The Arctic is an integrated system, the elements of which are closely linked by the atmosphere, ocean, and land. Using an integrated system approach, the book’s 30 chapters, written by a diverse team of leading scholars, carefully examine Arctic climate variability/change, large river hydrology, lakes and wetlands, snow cover and ice processes, permafrost characteristics, vegetation/landscape changes, and the future trajectory of Arctic system evolution. The discussions cover the fundamental features of and processes in the Arctic system, with a special focus on critical knowledge gaps, i.e., the interactions and feedbacks between water, permafrost, and ecosystem, such as snow pack and permafrost changes and their impacts on basin hydrology and ecology, river flow, geochemistry, and energy fluxes to the Arctic Ocean, and the structure and function of the Arctic ecosystem in response to past/future changes in climate, hydrology, and permafrost conditions. Given its scope, the book offers a valuable resource for researchers, graduate students, environmentalists, managers, and administrators who are concerned with the northern environment and resources.




Introduction to Spatial Econometrics


Book Description

Although interest in spatial regression models has surged in recent years, a comprehensive, up-to-date text on these approaches does not exist. Filling this void, Introduction to Spatial Econometrics presents a variety of regression methods used to analyze spatial data samples that violate the traditional assumption of independence between observat




Vegetation Dynamics


Book Description

Understanding ecosystem structure and function requires familiarity with the techniques, knowledge and concepts of the three disciplines of plant physiology, remote sensing and modelling. This is the first textbook to provide the fundamentals of these three domains in a single volume. It then applies cross-disciplinary insights to multiple case studies in vegetation and landscape science. A key feature of these case studies is an examination of relationships among climate, vegetation structure and vegetation function, to address fundamental research questions. This book is for advanced students and researchers who need to understand and apply knowledge from the disciplines of plant physiology, remote sensing and modelling. It allows readers to integrate and synthesise knowledge to produce a holistic understanding of the structure, function and behaviour of forests, woodlands and grasslands.




Use of the Normalized Difference Vegetation Index (NDVI) to Assess Land Degradation at Multiple Scales


Book Description

This report examines the scientific basis for the use of remotely sensed data, particularly Normalized Difference Vegetation Index (NDVI), primarily for the assessment of land degradation at different scales and for a range of applications, including resilience of agro-ecosystems. Evidence is drawn from a wide range of investigations, primarily from the scientific peer-reviewed literature but also non-journal sources. The literature review has been corroborated by interviews with leading specialists in the field. The report reviews the use of NDVI for a range of themes related to land degradation, including land cover change, drought monitoring and early warning systems, desertification processes, greening trends, soil erosion and salinization, vegetation burning and recovery after fire, biodiversity loss, and soil carbon. This SpringerBrief also discusses the limits of the use of NDVI for land degradation assessment and potential for future directions of use. A substantial body of peer-reviewed research lends unequivocal support for the use of coarse-resolution time series of NDVI data for studying vegetation dynamics at global, continental and sub-continental levels. There is compelling evidence that these data are highly correlated with biophysically meaningful vegetation characteristics such as photosynthetic capacity and primary production that are closely related to land degradation and to agroecosystem resilience.




The Normalized Difference Vegetation Index


Book Description

This book provides a coherent review of NDVI including its origin, its availability, its associated advantages and disadvantages, and its possible applications in ecology, environmental monitoring, wildlife management, and conservation.




Alaska's Changing Arctic


Book Description

In this edition of the Long Term Ecological Research Network series, editors John Hobbie and George Kling and 58 co-authors synthesize the findings from the NSF-funded Arctic LTER project based at Toolik Lake, Alaska, a site that has been active since the mid-1970s. The book presents research on the core issues of climate-change science in the treeless arctic region of Alaska. As a whole, it examines both terrestrial and freshwater-aquatic ecosystems, and their three typical habitats: tundra, streams, and lakes. The book provides a history of the Toolik Lake LTER site, and discusses its present condition and future outlook. It features contributions from top scientists from many fields, creating a multidisciplinary survey of the Alaskan arctic ecosystem. Chapter topics include glacial history, climatology, land-water interactions, mercury found in the Alaskan arctic, and the response of these habitats to environmental change. The final chapter predicts the consequences that arctic Alaska faces due to global warming and climate change, and discusses the future ecology of the LTER site in the region. Alaska's Changing Arctic is the definitive scientific survey of the past, present, and future of the ecology of the Alaskan arctic.