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Articles 151 - 180 of 232
Full-Text Articles in Geography
Recent Pause In The Growth Rate Of Atmospheric Co2 Due To Enhanced Terrestrial Carbon Uptake, Trevor F. Keenan, I. Colin Prentice, Josep G. Canadell, Christopher A. Williams, Han Wang, Michael Raupach, G. James Collatz
Recent Pause In The Growth Rate Of Atmospheric Co2 Due To Enhanced Terrestrial Carbon Uptake, Trevor F. Keenan, I. Colin Prentice, Josep G. Canadell, Christopher A. Williams, Han Wang, Michael Raupach, G. James Collatz
Geography
Terrestrial ecosystems play a significant role in the global carbon cycle and offset a large fraction of anthropogenic CO2 emissions. The terrestrial carbon sink is increasing, yet the mechanisms responsible for its enhancement, and implications for the growth rate of atmospheric CO2, remain unclear. Here using global carbon budget estimates, ground, atmospheric and satellite observations, and multiple global vegetation models, we report a recent pause in the growth rate of atmospheric CO2, and a decline in the fraction of anthropogenic emissions that remain in the atmosphere, despite increasing anthropogenic emissions. We attribute the observed decline to increases in the terrestrial …
Land System Science And Sustainable Development Of The Earth System: A Global Land Project Perspective, Peter H. Verburg, Neville Crossman, Erle C. Ellis, Andreas Heinimann, Patrick Hostert, Ole Mertz, Harini Nagendra, Thomas Sikor, Karl Heinz Erb, Nancy Golubiewski, Ricardo Grau, Morgan Grove, Souleymane Konaté, Patrick Meyfroidt, Dawn C. Parker, Rinku Roy Chowdhury, Hideaki Shibata, Allison Thomson, Lin Zhen
Land System Science And Sustainable Development Of The Earth System: A Global Land Project Perspective, Peter H. Verburg, Neville Crossman, Erle C. Ellis, Andreas Heinimann, Patrick Hostert, Ole Mertz, Harini Nagendra, Thomas Sikor, Karl Heinz Erb, Nancy Golubiewski, Ricardo Grau, Morgan Grove, Souleymane Konaté, Patrick Meyfroidt, Dawn C. Parker, Rinku Roy Chowdhury, Hideaki Shibata, Allison Thomson, Lin Zhen
Geography
Land systems are the result of human interactions with the natural environment. Understanding the drivers, state, trends and impacts of different land systems on social and natural processes helps to reveal how changes in the land system affect the functioning of the socio-ecological system as a whole and the tradeoff these changes may represent. The Global Land Project has led advances by synthesizing land systems research across different scales and providing concepts to further understand the feedbacks between social-and environmental systems, between urban and rural environments and between distant world regions. Land system science has moved from a focus on …
Rainfall Interception And The Coupled Surface Water And Energy Balance, Albert I.J.M. Van Dijk, John H. Gash, Eva Van Gorsel, Peter D. Blanken, Alessandro Cescatti, Carmen Emmel, Bert Gielen, Ian N. Harman, Gerard Kiely, Lutz Merbold, Leonardo Montagnani, Eddy Moors, Matteo Sottocornola, Andrej Varlagin, Christopher A. Williams, Georg Wohlfahrt
Rainfall Interception And The Coupled Surface Water And Energy Balance, Albert I.J.M. Van Dijk, John H. Gash, Eva Van Gorsel, Peter D. Blanken, Alessandro Cescatti, Carmen Emmel, Bert Gielen, Ian N. Harman, Gerard Kiely, Lutz Merbold, Leonardo Montagnani, Eddy Moors, Matteo Sottocornola, Andrej Varlagin, Christopher A. Williams, Georg Wohlfahrt
Geography
Evaporation from wet canopies (. E) can return up to half of incident rainfall back into the atmosphere and is a major cause of the difference in water use between forests and short vegetation. Canopy water budget measurements often suggest values of E during rainfall that are several times greater than those predicted from Penman-Monteith theory. Our literature review identified potential issues with both estimation approaches, producing several hypotheses that were tested using micrometeorological observations from 128 FLUXNET sites world-wide. The analysis shows that FLUXNET eddy-covariance measurements tend to provide unreliable measurements of E during rainfall. However, the other micrometeorological …
Forest Baseline And Deforestation Map Of The Dominican Republic Through The Analysis Of Time Series Of Modis Data, Florencia Sangermano, Leslie Bol, Pedro Galvis, Raymond E. Gullison, Jared Hardner, Gail S. Ross
Forest Baseline And Deforestation Map Of The Dominican Republic Through The Analysis Of Time Series Of Modis Data, Florencia Sangermano, Leslie Bol, Pedro Galvis, Raymond E. Gullison, Jared Hardner, Gail S. Ross
Geography
Deforestation is one of the major threats to habitats in the Dominican Republic. In this work we present a forest baseline for the year 2000 and a deforestation map for the year 2011. Maps were derived from Moderate Resolution Imaging Radiometer (MODIS) products at 250. m resolution. The vegetation continuous fields product (MOD44B) for the year 2000 was used to produce the forest baseline, while the vegetation indices product (MOD13Q1) was used to detect change between 2000 and 2011. Major findings based on the data presented here are reported in the manuscript "Habitat suitability and protection status of four species …
High Carbon And Biodiversity Costs From Converting Africa's Wet Savannahs To Cropland, Timothy D. Searchinger, Lyndon Estes, Philip K. Thornton, Tim Beringer, An Notenbaert, Daniel Rubenstein, Ralph Heimlich, Rachel Licker, Mario Herrero
High Carbon And Biodiversity Costs From Converting Africa's Wet Savannahs To Cropland, Timothy D. Searchinger, Lyndon Estes, Philip K. Thornton, Tim Beringer, An Notenbaert, Daniel Rubenstein, Ralph Heimlich, Rachel Licker, Mario Herrero
Geography
Do the wet savannahs and shrublands of Africa provide a large reserve of potential croplands to produce food staples or bioenergy with low carbon and biodiversity costs? We find that only small percentages of these lands have meaningful potential to be low-carbon sources of maize (1/42%) or soybeans (9.5-11.5%), meaning that their conversion would release at least one-third less carbon per ton of crop than released on average for the production of those crops on existing croplands. Factoring in land-use change, less than 1% is likely to produce cellulosic ethanol that would meet European standards for greenhouse gas reductions. Biodiversity …
Mapping Cropland In Smallholder-Dominated Savannas: Integrating Remote Sensing Techniques And Probabilistic Modeling, Sean Sweeney, Tatyana Ruseva, Lyndon Estes, Tom Evans
Mapping Cropland In Smallholder-Dominated Savannas: Integrating Remote Sensing Techniques And Probabilistic Modeling, Sean Sweeney, Tatyana Ruseva, Lyndon Estes, Tom Evans
Geography
Traditional smallholder farming systems dominate the savanna range countries of sub-Saharan Africa and provide the foundation for the region's food security. Despite continued expansion of smallholder farming into the surrounding savanna landscapes, food insecurity in the region persists. Central to the monitoring of food security in these countries, and to understanding the processes behind it, are reliable, high-quality datasets of cultivated land. Remote sensing has been frequently used for this purpose but distinguishing crops under certain stages of growth from savanna woodlands has remained a major challenge. Yet, crop production in dryland ecosystems is most vulnerable to seasonal climate variability, …
Preface: Climate Extremes And Biogeochemical Cycles In The Terrestrial Biosphere: Impacts And Feedbacks Across Scales, M. Bahn, M. Reichstein, K. Guan, J. M. Moreno, Christopher A. Williams
Preface: Climate Extremes And Biogeochemical Cycles In The Terrestrial Biosphere: Impacts And Feedbacks Across Scales, M. Bahn, M. Reichstein, K. Guan, J. M. Moreno, Christopher A. Williams
Geography
No abstract provided.
Implications Of Using 2 M Versus 30 M Spatial Resolution Data For Suburban Residential Land Change Modeling, S. D. Blanchard, R. G. Pontius, K. M. Urban
Implications Of Using 2 M Versus 30 M Spatial Resolution Data For Suburban Residential Land Change Modeling, S. D. Blanchard, R. G. Pontius, K. M. Urban
Geography
This study assesses the advantages and disadvantages of using 2 m spatial resolution data versus 30 m resolution data for a simulation model of land-use and land-cover change (LUCC). The model projects LUCC from 2005 to 2055 in the town of Lynnfield, Massachusetts, USA. This article describes four scenario storylines and then projects land-use and land-cover under each of the four scenarios with 2 m data and again with 30 m data. The disagreement between the 2 m output and its corresponding 30 m output ranges between 5.7% and 11.0% of the town. The disagreement due to allocation over small …
New Perspectives On An Iconic Landscape From Comparative International Long-Term Ecological Research, Evelyn E. Gaiser, Elizabeth P. Anderson, Edward Castañeda-Moya, Ligia Collado-Vides, James W.F. Ourqurean, Michael R. Heithaus, Rudolf Jaffé, David Lagomasino, Nicholas J. Oehm, Rene M. Price, Victor H. Rivera-Monroy, Rinku Roy Chowdhury, Tiffany G. Troxler
New Perspectives On An Iconic Landscape From Comparative International Long-Term Ecological Research, Evelyn E. Gaiser, Elizabeth P. Anderson, Edward Castañeda-Moya, Ligia Collado-Vides, James W.F. Ourqurean, Michael R. Heithaus, Rudolf Jaffé, David Lagomasino, Nicholas J. Oehm, Rene M. Price, Victor H. Rivera-Monroy, Rinku Roy Chowdhury, Tiffany G. Troxler
Geography
Iconic ecosystems like the Florida Coastal Everglades can serve as sentinels of environmental change from local to global scales. This characteristic can help inform general theory about how and why ecosystems transform, particularly if distinctive ecosystem properties are studied over long time scales and compared to those of similar ecosystems elsewhere. Here we review the ways in which long-term, comparative, international research has provided perspectives on iconic features of the Everglades that have, in turn, informed general ecosystem paradigms. Studies in other comparable wetlands from the Caribbean to Australia have shed light on distinctive and puzzling aspects such as the …
The Predicts Database: A Global Database Of How Local Terrestrial Biodiversity Responds To Human Impacts, Lawrence N. Hudson, Tim Newbold, Sara Contu, Samantha L.L. Hill, Igor Lysenko, Adriana De Palma, Helen R.P. Phillips, Rebecca A. Senior, Dominic J. Bennett, Hollie Booth, Argyrios Choimes, David L.P. Correia, Julie Day, Susy Echeverría-Londoño, Morgan Garon, Michelle L.K. Harrison, Daniel J. Ingram, Martin Jung, Victoria Kemp, Lucinda Kirkpatrick, Callum D. Martin, Yuan Pan, Hannah J. White, Job Aben, Stefan Abrahamczyk, Gilbert B. Adum, Virginia Aguilar-Barquero, Marcelo A. Aizen, Marc Ancrenaz, Enrique Arbeláez-Cortés, Inge Armbrecht, Badrul Azhar, Christopher A. Williams
The Predicts Database: A Global Database Of How Local Terrestrial Biodiversity Responds To Human Impacts, Lawrence N. Hudson, Tim Newbold, Sara Contu, Samantha L.L. Hill, Igor Lysenko, Adriana De Palma, Helen R.P. Phillips, Rebecca A. Senior, Dominic J. Bennett, Hollie Booth, Argyrios Choimes, David L.P. Correia, Julie Day, Susy Echeverría-Londoño, Morgan Garon, Michelle L.K. Harrison, Daniel J. Ingram, Martin Jung, Victoria Kemp, Lucinda Kirkpatrick, Callum D. Martin, Yuan Pan, Hannah J. White, Job Aben, Stefan Abrahamczyk, Gilbert B. Adum, Virginia Aguilar-Barquero, Marcelo A. Aizen, Marc Ancrenaz, Enrique Arbeláez-Cortés, Inge Armbrecht, Badrul Azhar, Christopher A. Williams
Geography
Biodiversity continues to decline in the face of increasing anthropogenic pressures such as habitat destruction, exploitation, pollution and introduction of alien species. Existing global databases of species' threat status or population time series are dominated by charismatic species. The collation of datasets with broad taxonomic and biogeographic extents, and that support computation of a range of biodiversity indicators, is necessary to enable better understanding of historical declines and to project - and avert - future declines. We describe and assess a new database of more than 1.6 million samples from 78 countries representing over 28,000 species, collated from existing spatial …
Mapping Licit And Illicit Mining Activity In The Madre De Dios Region Of Peru, Arthur Elmes, Josué Gabriel Yarlequé Ipanaqué, John Rogan, Nicholas Cuba, Anthony J. Bebbington
Mapping Licit And Illicit Mining Activity In The Madre De Dios Region Of Peru, Arthur Elmes, Josué Gabriel Yarlequé Ipanaqué, John Rogan, Nicholas Cuba, Anthony J. Bebbington
Geography
Since the early 2000s, the Madre de Dios Region of southern Peru has experienced rapid expansion of both licit and illicit mining activities, in the form of artisanal and small-scale mining (ASM). ASM typically takes place in remote, inaccessible locations and is therefore difficult to monitor in situ. This paper explores the utility of Landsat-5 imagery via decision tree classification to determine ASM locations in Madre de Dios. Spectral mixture analysis was used to unmix Landsat imagery, using WorldView and QuickBird l imagery to aid spectral endmember selection and validate AMS maps. The ASM maps had an overall area-weighted accuracy …
Land Classification And Change Intensity Analysis In A Coastal Watershed Of Southeast China, Pei Zhou, Jinliang Huang, Robert Gilmore Pontius, Huasheng Hong
Land Classification And Change Intensity Analysis In A Coastal Watershed Of Southeast China, Pei Zhou, Jinliang Huang, Robert Gilmore Pontius, Huasheng Hong
Geography
The aim of this study is to improve the understanding of land changes in the Jiulong River watershed, a coastal watershed of Southeast China. We developed a stratified classification methodology for land mapping, which combines linear stretching, an Iterative Self-Organizing Data Analysis (ISODATA) clustering algorithm, and spatial reclassification. The stratified classification for 2002 generated less overall error than an unstratified classification. The stratified classifications were then used to examine temporal differences at 1986, 1996, 2002, 2007 and 2010. Intensity Analysis was applied to analyze land changes at three levels: time interval, category, and transition. Results showed that land use transformation …
Changing Water Availability During The African Maize-Growing Season, 1979-2010, Lyndon Estes, Nathaniel W. Chaney, Julio Herrera-Estrada, Justin Sheffield, Kelly K. Caylor, Eric F. Wood
Changing Water Availability During The African Maize-Growing Season, 1979-2010, Lyndon Estes, Nathaniel W. Chaney, Julio Herrera-Estrada, Justin Sheffield, Kelly K. Caylor, Eric F. Wood
Geography
Understanding how global change is impacting African agriculture requires a full physical accounting of water supply and demand, but accurate, gridded data on key drivers (e.g., humidity) are generally unavailable. We used a new bias-corrected meteorological dataset to analyze changes in precipitation (supply), potential evapotranspiration (Ep, demand), and water availability (expressed as the ratio P/Ep) in 20 countries (focusing on their maize-growing regions and seasons), between 1979 and 2010, and the factors driving changes in Ep. Maizegrowing areas in Southern Africa, particularly South Africa, benefitted from increased water availability due in large part to demand declines driven primarily by declining …
Spatially-Explicit Simulation Of Urban Growth Through Self-Adaptive Genetic Algorithm And Cellular Automata Modelling, Yan Liu, Yongjiu Feng, Robert Gilmore Pontius
Spatially-Explicit Simulation Of Urban Growth Through Self-Adaptive Genetic Algorithm And Cellular Automata Modelling, Yan Liu, Yongjiu Feng, Robert Gilmore Pontius
Geography
This paper presents a method to optimise the calibration of parameters and land use transition rules of a cellular automata (CA) urban growth model using a self-adaptive genetic algorithm (SAGA). Optimal calibration is achieved through an algorithm that minimises the difference between the simulated and observed urban growth. The model was applied to simulate land use change from non-urban to urban in South East Queensland's Logan City, Australia, from 1991 to 2001. The performance of the calibrated model was evaluated by comparing the empirical land use change maps from the Landsat imagery to the simulated land use change produced by …
Validation Of Satellite Rainfall Products For Western Uganda., Jeremy E. Diem, Joel N. Hartter, Sadie J. Ryan, Michael W. Palace
Validation Of Satellite Rainfall Products For Western Uganda., Jeremy E. Diem, Joel N. Hartter, Sadie J. Ryan, Michael W. Palace
Geography
Central equatorial Africa is deficient in long-term, ground-based measurements of rainfall; therefore, the aim of this study is to assess the accuracy of three high-resolution, satellite-based rainfall products in western Uganda for the 2001–10 period. The three products are African Rainfall Climatology, version 2 (ARC2); African Rainfall Estimation Algorithm, version 2 (RFE2); and 3B42 from the Tropical Rainfall Measuring Mission, version 7 (i.e., 3B42v7). Daily rainfall totals from six gauges were used to assess the accuracy of satellite-based rainfall estimates of rainfall days, daily rainfall totals, 10-day rainfall totals, monthly rainfall totals, and seasonal rainfall totals. The northern stations had …
Hog Daddy And The Walls Of Steel: Catch Shares And Ecosystem Change In The New England Groundfishery, Jennifer F. Brewer
Hog Daddy And The Walls Of Steel: Catch Shares And Ecosystem Change In The New England Groundfishery, Jennifer F. Brewer
Geography
The U.S. National Oceanic and Atmospheric Administration implemented marketbased fishery management in the New England groundfishery as catch shares, controlling aggregate harvests through tradable annual catch quotas allocated to fishing groups called sectors. Policy supporters assert that resulting markets raise conservation incentives. In compliance with the Magnuson–Stevens Fishery Conservation and Management Act, species assessments permit catch shares to replace more spatially and temporally specific constraints on fishing gear, time, areas, and daily harvest limits. Qualitative evidence from field interviews and participant observation questions the efficacy of catch shares. Fishing industry members observe that increased presence of large trawl vessels in …
Harvesting A Knowledge Commons: Collective Action, Transparency, And Innovation At The Portland Fish Exchange, Jennifer F. Brewer
Harvesting A Knowledge Commons: Collective Action, Transparency, And Innovation At The Portland Fish Exchange, Jennifer F. Brewer
Geography
While localist visions of alternative food systems advocate for the expansion of local ecological knowledge through more proximate producerconsumer relationships, globalized seafood supply-demand chains persist. Moving beyond this dichotomy, commons scholars recognize that collective action among resource users at the local level can shape cross-scalar producer relations with government and more capitalized firms operating in regional and global markets. In the case of the New England groundfishery, a quasi-public fish auction not only transformed the scalar, logistical, and financial parameters of harvester-buyer relationships, it altered the production and use of local knowledge among some harvesters, and their technological choices. Resulting …
Decolonizing Cascadia?, Wes Attewell, Dan Cohen, Juliane Collard, Rosemary Collard, Lisa Dumoulin, May Farrales, Alan Grove, Jessica Hallenbeck, Sarah Hunt, Samuel Johns, Kyle Loewen, Jonathan Luedee, Alan Mcconchie, Paige Patchin, Sage Ponder, Sarah Mathisen Przedpelska, Carolyn Prouse, Duncan Ranslem, Max Ritts, Emily Rosenman, Sam Walker, Sophie Webber
Decolonizing Cascadia?, Wes Attewell, Dan Cohen, Juliane Collard, Rosemary Collard, Lisa Dumoulin, May Farrales, Alan Grove, Jessica Hallenbeck, Sarah Hunt, Samuel Johns, Kyle Loewen, Jonathan Luedee, Alan Mcconchie, Paige Patchin, Sage Ponder, Sarah Mathisen Przedpelska, Carolyn Prouse, Duncan Ranslem, Max Ritts, Emily Rosenman, Sam Walker, Sophie Webber
Geography
This essay reflects on attempts to organize a conference that sought to trouble the colonial nature of conference structures, academic knowledges and hierarchies, and the ‘Cascadia’ bioregion of Northwestern North America.
Convergent Surface Water Distributions In U.S. Cities, M. K. Steele, J. B. Heffernan, N. Bettez, J. Cavender-Bares, P. M. Groffman, J. M. Grove, S. Hall, S. E. Hobbie, K. Larson, J. L. Morse, C. Neill, K. C. Nelson, J. O'Neil-Dunne, L. Ogden, D. E. Pataki, C. Polsky, Rinku Roy Chowdhury
Convergent Surface Water Distributions In U.S. Cities, M. K. Steele, J. B. Heffernan, N. Bettez, J. Cavender-Bares, P. M. Groffman, J. M. Grove, S. Hall, S. E. Hobbie, K. Larson, J. L. Morse, C. Neill, K. C. Nelson, J. O'Neil-Dunne, L. Ogden, D. E. Pataki, C. Polsky, Rinku Roy Chowdhury
Geography
Earth's surface is rapidly urbanizing, resulting in dramatic changes in the abundance, distribution and character of surface water features in urban landscapes. However, the scope and consequences of surface water redistribution at broad spatial scales are not well understood. We hypothesized that urbanization would lead to convergent surface water abundance and distribution: in other words, cities will gain or lose water such that they become more similar to each other than are their surrounding natural landscapes. Using a database of more than 1 million water bodies and 1 million km of streams, we compared the surface water of 100 US …
Extractive Industries, Livelihoods And Natural Resource Competition: Mapping Overlapping Claims In Peru And Ghana, Nicholas Cuba, Anthony J. Bebbington, John Rogan, Marco Millones
Extractive Industries, Livelihoods And Natural Resource Competition: Mapping Overlapping Claims In Peru And Ghana, Nicholas Cuba, Anthony J. Bebbington, John Rogan, Marco Millones
Geography
Taking the cases of Perú and Ghana, this paper examines overlaps between the extraction of minerals, oil and gas on the one hand, and river basins, agricultural land use, and protected areas on the other hand. In particular the paper considers how far such overlaps can be revealed and analyzed on the basis of (relatively) accessible and affordable data, without having to use more expensive data generated by remote sensing or fieldwork. We use concessions as our indicator of the presence of extractive industry activity, focusing on both mineral and hydrocarbon concessions, and areas of exploration and of active resource …
Heat And Drought Extremes Likely To Stress Ecosystem Productivity Equally Or More In A Warmer, Co2rich Future, Christopher A. Williams
Heat And Drought Extremes Likely To Stress Ecosystem Productivity Equally Or More In A Warmer, Co2rich Future, Christopher A. Williams
Geography
Reduced carbon uptake caused by recent heat and drought extremes raises concerns about biospheric feedbacks that amplify global warming. However, elevated carbon dioxide is expected to boost terrestrial ecosystem productivity over the 21st century, potentially alleviating some of the adverse carbon impacts of climate extremes. Using CMIP5 earth system model (ESM) results, Ian Williams and colleagues (2014 Environ. Res. Lett. 9 094011) find that the carbon impacts of heat and drought extremes in the future are likely to be similar to those seen in today's climate only shifted toward fluctuations around a higher average temperature. However, they also find that …
A Full Greenhouse Gases Budget Of Africa: Synthesis, Uncertainties, And Vulnerabilities, R. Valentini, A. Arneth, A. Bombelli, S. Castaldi, R. Cazzolla Gatti, F. Chevallier, P. Ciais, E. Grieco, J. Hartmann, M. Henry, R. A. Houghton, M. Jung, W. L. Kutsch, Y. Malhi, E. Mayorga, L. Merbold, G. Murray-Tortarolo, D. Papale, P. Peylin, B. Poulter, P. A. Raymond, M. Santini, S. Sitch, G. Vaglio Laurin, G. R. Van Der Werf, Christopher A. Williams, R. J. Scholes
A Full Greenhouse Gases Budget Of Africa: Synthesis, Uncertainties, And Vulnerabilities, R. Valentini, A. Arneth, A. Bombelli, S. Castaldi, R. Cazzolla Gatti, F. Chevallier, P. Ciais, E. Grieco, J. Hartmann, M. Henry, R. A. Houghton, M. Jung, W. L. Kutsch, Y. Malhi, E. Mayorga, L. Merbold, G. Murray-Tortarolo, D. Papale, P. Peylin, B. Poulter, P. A. Raymond, M. Santini, S. Sitch, G. Vaglio Laurin, G. R. Van Der Werf, Christopher A. Williams, R. J. Scholes
Geography
This paper, developed under the framework of the RECCAP initiative, aims at providing improved estimates of the carbon and GHG (CO2, CH4 and N2O) balance of continental Africa. The various components and processes of the African carbon and GHG budget are considered, existing data reviewed, and new data from different methodologies (inventories, ecosystem flux measurements, models, and atmospheric inversions) presented. Uncertainties are quantified and current gaps and weaknesses in knowledge and monitoring systems described in order to guide future requirements. The majority of results agree that Africa is a small sink of carbon on an annual scale, with an average …
Impacts Of Disturbance History On Forest Carbon Stocks And Fluxes: Merging Satellite Disturbance Mapping With Forest Inventory Data In A Carbon Cycle Model Framework, Christopher A. Williams, G. James Collatz, Jeffrey Masek, Chengquan Huang, Samuel N. Goward
Impacts Of Disturbance History On Forest Carbon Stocks And Fluxes: Merging Satellite Disturbance Mapping With Forest Inventory Data In A Carbon Cycle Model Framework, Christopher A. Williams, G. James Collatz, Jeffrey Masek, Chengquan Huang, Samuel N. Goward
Geography
Forest carbon stocks and fluxes are highly dynamic following stand-clearing disturbances from severe fire and harvest and this presents a significant challenge for continental carbon budget assessments. In this work we use forest inventory data to parameterize a carbon cycle model to represent post-disturbance carbon trajectories of carbon pools and fluxes for specific forest types growing in high and low site productivity class settings. We then apply these trajectories to landscapes and regions based on forest age distributions derived from either the FIA data or from Landsat time series stacks (1985-2006) for 54 representative scenes throughout most of the conterminous …
The Research Journey: Travels Across The Idiomatic And Axiomatic Toward A Better Understanding Of Complexity, Katharine A. Mcgowan, Frances Westley, Evan D.G. Fraser, Philip A. Loring, Kathleen C. Weathers, Flor Avelino, Jan Sendzimir, Rinku Roy Chowdhury, Michele Lee Moore
The Research Journey: Travels Across The Idiomatic And Axiomatic Toward A Better Understanding Of Complexity, Katharine A. Mcgowan, Frances Westley, Evan D.G. Fraser, Philip A. Loring, Kathleen C. Weathers, Flor Avelino, Jan Sendzimir, Rinku Roy Chowdhury, Michele Lee Moore
Geography
In this paper, seven researchers reflect on the journeys their research projects have taken when they engage with and synthesize complex problems. These journeys embody an adaptive approach to tackling problems characterized by their interconnectedness and emergence, and that transcend traditional units of analysis such as ecosystems. In this paper we argue that making such a process deliberate and explicit will help researchers better combine different research paradigms such as expert-driven and participant-directed work, thus resulting in both broad explanations and specific phenomenon; research tensions traditionally defined as oppositional must be approached as complimentary. This paper includes researchers’ personal journeys …
Spatiotemporal Patterns And Socioeconomic Contexts Of Vegetative Cover In Altamira City, Brazil, Scott Hetrick, Rinku Roy Chowdhury, Eduardo Brondizio, Emilio Moran
Spatiotemporal Patterns And Socioeconomic Contexts Of Vegetative Cover In Altamira City, Brazil, Scott Hetrick, Rinku Roy Chowdhury, Eduardo Brondizio, Emilio Moran
Geography
Ecosystem services provided by urban vegetation can ameliorate problems common to urban environments while improving the quality of life of urban residents. Much research in urban ecology has analyzed urban environmental dynamics in the global north; rapidly urbanizing areas in the global south have not received commensurate attention. The land cover dynamics of mid-sized cities in the global south remain under-explored in particular. In this article, we investigate the spatial patterns and socioeconomic contexts of urban vegetation in Altamira, Brazil, a mid-sized but rapidly expanding city in the Amazon. Using time series remotely sensed imagery, we profile changes in urban …
Spatially Explicit Data: Stewardship And Ethical Challenges In Science, Joel N. Hartter, Sadie J. Ryan, Catrina A. Mackenzie, John N. Parker, Carly A. Strasser
Spatially Explicit Data: Stewardship And Ethical Challenges In Science, Joel N. Hartter, Sadie J. Ryan, Catrina A. Mackenzie, John N. Parker, Carly A. Strasser
Geography
Scholarly communication is at an unprecedented turning point created in part by the increasing saliency of data stewardship and data sharing. Formal data management plans represent a new emphasis in research, enabling access to data at higher volumes and more quickly, and the potential for replication and augmentation of existing research. Data sharing has recently transformed the practice, scope, content, and applicability of research in several disciplines, in particular in relation to spatially specific data. This lends exciting potentiality, but the most effective ways in which to implement such changes, particularly for disciplines involving human subjects and other sensitive information, …
Design And Interpretation Of Intensity Analysis Illustrated By Land Change In Central Kalimantan, Indonesia, Robert Gilmore Pontius, Yan Gao, Nicholas M. Giner, Takashi Kohyama, Mitsuru Osaki, Kazuyo Hirose
Design And Interpretation Of Intensity Analysis Illustrated By Land Change In Central Kalimantan, Indonesia, Robert Gilmore Pontius, Yan Gao, Nicholas M. Giner, Takashi Kohyama, Mitsuru Osaki, Kazuyo Hirose
Geography
Intensity Analysis has become popular as a top-down hierarchical accounting framework to analyze differences among categories, such as changes in land categories over time. Some aspects of interpretation are straightforward, while other aspects require deeper thought. This article explains how to interpret Intensity Analysis with respect to four concepts. First, we illustrate how to analyze whether error could account for non-uniform changes. Second, we explore two types of the large dormant category phenomenon. Third, we show how results can be sensitive to the selection of the domain. Fourth, we explain how Intensity Analysis' symmetric top-down hierarchy influences interpretation with respect …
A Suite Of Tools For Roc Analysis Of Spatial Models, Jean François Mas, Britaldo Soares Filho, Robert Gilmore Pontius, Michelle Farfán Gutiérrez, Hermann Rodrigues
A Suite Of Tools For Roc Analysis Of Spatial Models, Jean François Mas, Britaldo Soares Filho, Robert Gilmore Pontius, Michelle Farfán Gutiérrez, Hermann Rodrigues
Geography
The Receiver Operating Characteristic (ROC) is widely used for assessing the performance of classification algorithms. In GIScience, ROC has been applied to assess models aimed at predicting events, such as land use/cover change (LUCC), species distribution and disease risk. However, GIS software packages offer few statistical tests and guidance tools for ROC analysis and interpretation. This paper presents a suite of GIS tools designed to facilitate ROC curve analysis for GIS users by applying proper statistical tests and analysis procedures. The tools are freely available as models and submodels of Dinamica EGO freeware. The tools give the ROC curve, the …
Measuring The Temporal Instability Of Land Change Using The Flow Matrix, D. S.M. Runfola, Robert Gilmore Pontius
Measuring The Temporal Instability Of Land Change Using The Flow Matrix, D. S.M. Runfola, Robert Gilmore Pontius
Geography
This article introduces the Flow matrix, which expresses the sizes of transitions among categories between two time points. We use the Flow matrix to create a metric R that measures the instability of annual change among time intervals that partition the time extent. Specifically, R is the proportion of change that would need to be reallocated to different time interval(s) to achieve uniform change during the time extent. This article computes R for 10 Long Term Ecological Research (LTER) sites and for seven case studies from published land change data. Of the 10 LTER sites analyzed, the Andrews site in …
Global Trends In Seasonality Of Normalized Difference Vegetation Index (Ndvi), 1982-2011, J. Ronald Eastman, Florencia Sangermano, Elia A. Machado, John Rogan, Assaf Anyamba
Global Trends In Seasonality Of Normalized Difference Vegetation Index (Ndvi), 1982-2011, J. Ronald Eastman, Florencia Sangermano, Elia A. Machado, John Rogan, Assaf Anyamba
Geography
A 30-year series of global monthly Normalized Difference Vegetation Index (NDVI) imagery derived from the Global Inventory Modeling and Mapping Studies (GIMMS) NDVI3g archive was analyzed for the presence of trends in changing seasonality. Using the Seasonal Trend Analysis (STA) procedure, over half (56.30%) of land surfaces were found to exhibit significant trends. Almost half (46.10%) of the significant trends belonged to three classes of seasonal trends (or changes). Class 1 consisted of areas that experienced a uniform increase in NDVI throughout the year, and was primarily associated with forested areas, particularly broadleaf forests. Class 2 consisted of areas experiencing …