Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Physical Sciences and Mathematics (15)
- Remote Sensing (14)
- Life Sciences (10)
- Nature and Society Relations (10)
- Environmental Sciences (8)
-
- Forest Sciences (8)
- Environmental Policy (7)
- Public Affairs, Public Policy and Public Administration (7)
- Sociology (6)
- Development Studies (5)
- Oceanography (5)
- Oceanography and Atmospheric Sciences and Meteorology (5)
- Place and Environment (5)
- Economics (4)
- Physical and Environmental Geography (4)
- Sustainability (4)
- Agricultural and Resource Economics (3)
- Environmental Studies (3)
- Geographic Information Sciences (3)
- Human Geography (3)
- Natural Resources Management and Policy (3)
- Urban Studies and Planning (3)
- Civic and Community Engagement (2)
- Earth Sciences (2)
- Forest Management (2)
- Political Economy (2)
- Spatial Science (2)
- Theory, Knowledge and Science (2)
- Keyword
-
- Climate change (20)
- Remote sensing (17)
- Student Publications (16)
- Land use (11)
- Land cover (10)
-
- MODIS (8)
- Agriculture (7)
- Biodiversity (7)
- Drought (7)
- Africa (6)
- Carbon dioxide (6)
- Deforestation (6)
- Landsat (6)
- Urban ecology (6)
- Brazil (5)
- Carbon cycle (5)
- Data set (5)
- GIS (5)
- Machine learning (5)
- United States (5)
- Urbanization (5)
- Wildfire (5)
- Accuracy (4)
- Accuracy assessment (4)
- Biogeochemistry (4)
- Carbon (4)
- Carbon sink (4)
- Change (4)
- Conservation (4)
- Ecosystem (4)
Articles 181 - 210 of 231
Full-Text Articles in Geography
Global Land Governance: From Territory To Flow?, Thomas Sikor, Graeme Auld, Anthony J. Bebbington, Tor A. Benjaminsen, Bradford S. Gentry, Carol Hunsberger, Anne Marie Izac, Matias E. Margulis, Tobias Plieninger, Heike Schroeder, Caroline Upton
Global Land Governance: From Territory To Flow?, Thomas Sikor, Graeme Auld, Anthony J. Bebbington, Tor A. Benjaminsen, Bradford S. Gentry, Carol Hunsberger, Anne Marie Izac, Matias E. Margulis, Tobias Plieninger, Heike Schroeder, Caroline Upton
Geography
This article reviews recent research on contemporary transformations of global land governance. It shows how changes in global governance have facilitated and responded to radical revalorizations of land, together driving the intensified competition and struggles over land observed in many other contributions to this special issue. The rules in place to govern land use are shifting from 'territorial' toward 'flow-centered' arrangements, the latter referring to governance that targets particular flows of resources or goods, such as certification of agricultural or wood products. The intensifying competition over land coupled with shifts toward flow-centered governance has generated land uses involving new forms …
Ice Sheet Record Of Recent Sea-Ice Behavior And Polynya Variability In The Amundsen Sea, West Antarctica, Alison S. Criscitiello, Sarah B. Das, Matthew J. Evans, Karen E. Frey, Howard Conway, Ian Joughin, Brooke Medley, Eric J. Steig
Ice Sheet Record Of Recent Sea-Ice Behavior And Polynya Variability In The Amundsen Sea, West Antarctica, Alison S. Criscitiello, Sarah B. Das, Matthew J. Evans, Karen E. Frey, Howard Conway, Ian Joughin, Brooke Medley, Eric J. Steig
Geography
[1] Our understanding of past sea-ice variability is limited by the short length of satellite and instrumental records. Proxy records can extend these observations but require further development and validation. We compare methanesulfonic acid (MSA) and chloride (Cl-) concentrations from a new firn core from coastal West Antarctica with satellite-derived observations of regional sea-ice concentration (SIC) in the Amundsen Sea (AS) to evaluate spatial and temporal correlations from 2002-2010. The high accumulation rate (∼39 g·cm-2·yr-1) provides monthly resolved records of MSA and Cl-, allowing detailed investigation of how regional SIC is recorded in the ice-sheet stratigraphy. Over the period 2002-2010 …
Satellite-Based Estimates Of Antarctic Surface Meltwater Fluxes, Luke D. Trusel, Karen E. Frey, Sarah B. Das, Peter Kuipers Munneke, Michiel R. Van Den Broeke
Satellite-Based Estimates Of Antarctic Surface Meltwater Fluxes, Luke D. Trusel, Karen E. Frey, Sarah B. Das, Peter Kuipers Munneke, Michiel R. Van Den Broeke
Geography
This study generates novel satellite-derived estimates of Antarctic-wide annual (1999-2009) surface meltwater production using an empirical relationship between radar backscatter from the QuikSCAT (QSCAT) satellite and melt calculated from in situ energy balance observations. The resulting QSCAT-derived melt fluxes significantly agree with output from the regional climate model RACMO2.1 and with independent ground-based observations. The high-resolution (4.45 km) QSCAT-based melt fluxes uniquely detect interannually persistent and intense melt (>400 mm water equivalent (w.e.) year-1) on interior Larsen C Ice Shelf that is not simulated by RACMO2.1. This supports a growing understanding of the importance of a föhn effect in …
Do Bark Beetle Outbreaks Increase Wildfire Risks In The Central U.S. Rocky Mountains? Implications From Recent Research, Scott H. Black, Dominik Kulakowski, Barry R. Noon, Dominick A. Dellasala
Do Bark Beetle Outbreaks Increase Wildfire Risks In The Central U.S. Rocky Mountains? Implications From Recent Research, Scott H. Black, Dominik Kulakowski, Barry R. Noon, Dominick A. Dellasala
Geography
Appropriate response to recent, widespread bark beetle (Dendroctonus spp.) outbreaks in the western United States has been the subject of much debate in scientific and policy circles. Among the proposed responses have been landscape-level mechanical treatments to prevent the further spread of outbreaks and to reduce the fire risk that is believed to be associated with insect-killed trees. We review the literature on the efficacy of silvicutural practices to control outbreaks and on fire risk following bark beetle outbreaks in several forest types. While research is ongoing and important questions remain unresolved, to date most available evidence indicates that bark …
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 …
The Role Of Landscape Connectivity In Planning And Implementing Conservation And Restoration Priorities. Issues In Ecology, Doborah Rudnick, Sadie J. Ryan, Paul Beier, Samual A. Cushman, Fred Dieffenbach, Clinton Epps, Leah R. Gerber, Joel N. Hartter, Jeff S. Jenness, Julia Kintsch, Adina M. Merenlender, Ryan M. Perkl, Damian V. Perziosi, Stephen C. Trombulack
The Role Of Landscape Connectivity In Planning And Implementing Conservation And Restoration Priorities. Issues In Ecology, Doborah Rudnick, Sadie J. Ryan, Paul Beier, Samual A. Cushman, Fred Dieffenbach, Clinton Epps, Leah R. Gerber, Joel N. Hartter, Jeff S. Jenness, Julia Kintsch, Adina M. Merenlender, Ryan M. Perkl, Damian V. Perziosi, Stephen C. Trombulack
Geography
Landscape connectivity, the extent to which a landscape facilitates the movements of organisms and their genes, faces critical threats from both fragmentation and habitat loss. Many conservation efforts focus on protecting and enhancing connectivity to offset the impacts of habitat loss and fragmentation on biodiversity conservation, and to increase the resilience of reserve networks to potential threats associated with climate change. Loss of connectivity can reduce the size and quality of available habitat, impede and disrupt movement (including dispersal) to new habitats, and affect seasonal migration patterns. These changes can lead, in turn, to detrimental effects for populations and species, …
Predicting How Adaptation To Climate Change Could Affect Ecological Conservation: Secondary Impacts Of Shifting Agricultural Suitability, Bethany A. Bradley, Lyndon D. Estes, David G. Hole, Stephen Holness, Michael Oppenheimer, Will R. Turner, Hein Beukes, Roland E. Schulze, Mark A. Tadross, David S. Wilcove
Predicting How Adaptation To Climate Change Could Affect Ecological Conservation: Secondary Impacts Of Shifting Agricultural Suitability, Bethany A. Bradley, Lyndon D. Estes, David G. Hole, Stephen Holness, Michael Oppenheimer, Will R. Turner, Hein Beukes, Roland E. Schulze, Mark A. Tadross, David S. Wilcove
Geography
Aim: Ecosystems face numerous well-documented threats from climate change. The well-being of people also is threatened by climate change, most prominently by reduced food security. Human adaptation to food scarcity, including shifting agricultural zones, will create new threats for natural ecosystems. We investigated how shifts in crop suitability because of climate change may overlap currently protected areas (PAs) and priority sites for PA expansion in South Africa. Predicting the locations of suitable climate conditions for crop growth will assist conservationists and decision-makers in planning for climate change. Location: South Africa. Methods: We modelled climatic suitability in 2055 for maize and …
Revisiting Maine’S Lobster Commons: Rescaling Political Subjects, Jennifer F. Brewer
Revisiting Maine’S Lobster Commons: Rescaling Political Subjects, Jennifer F. Brewer
Geography
Calls for cross-scalar theoretical and methodological approaches are not new to commons scholarship. Such efforts might be hastened by channelling poststructuralist and critical theory perspectives through the geographic subfield of political ecology, including attention to political scales and subjects. Toward this end, this paper reconsiders Maine’s lobster fishery. This case has provided rich material for watershed commons scholarship, demonstrating the ability of social groups to conserve resources independent of government or markets, and it continues to offer new findings. Recent fieldwork shows that as lobster boat captains advance collective interests through state-supported co-management governance arrangements, concerns of crew and non-fishing …
Antarctic Surface Melting Dynamics: Enhanced Perspectives From Radar Scatterometer Data, L. D. Trusel, K. E. Frey, S. B. Das
Antarctic Surface Melting Dynamics: Enhanced Perspectives From Radar Scatterometer Data, L. D. Trusel, K. E. Frey, S. B. Das
Geography
Antarctic ice sheet surface melting can regionally influence ice shelf stability, mass balance, and glacier dynamics, in addition to modulating near-surface physical and chemical properties over wide areas. Here, we investigate variability in surface melting from 1999 to 2009 using radar backscatter time series from the SeaWinds scatterometer aboard the QuikSCAT satellite. These daily, continent-wide observations are explored in concert with in situ meteorological records to validate a threshold-based melt detection method. Radar backscatter decreases during melting are significantly correlated with in situ positive degree-days as well as meltwater production determined from energy balance modeling at Neumayer Station, East Antarctica. …
Accelerating Anthropogenic Land Surface Change And The Status Of Pleistocene Drumlins In New England, Deborah W. Woodcock, John S. Rogan, Samuel D. Blanchard
Accelerating Anthropogenic Land Surface Change And The Status Of Pleistocene Drumlins In New England, Deborah W. Woodcock, John S. Rogan, Samuel D. Blanchard
Geography
Drumlins are glacially derived landforms that are prominent in the landscape over much of southern New England. We carried out a comprehensive ground-based survey in a three-town study area in eastern Massachusetts with the goals of establishing the extent to drumlins have been altered and assessing the associated environmental consequences and probable driving factors. Results show that many drumlins have been significantly altered through levelling and truncation (creation of steep cut and fill slopes), with projects involving movement of 1-1.5×106 m3 of earth materials not now uncommon. Stormwater and wetlands infractions were documented at all the larger excavation sites and …
Heterogeneity In Residential Yard Care: Evidence From Boston, Miami, And Phoenix, Edmund M. Harris, Colin Polsky, Kelli L. Larson, Rebecca Garvoille, Deborah Martin, Jaleila Brumand, Laura Ogden
Heterogeneity In Residential Yard Care: Evidence From Boston, Miami, And Phoenix, Edmund M. Harris, Colin Polsky, Kelli L. Larson, Rebecca Garvoille, Deborah Martin, Jaleila Brumand, Laura Ogden
Geography
The management of residential landscapes occurs within a complex socio-ecological system linking household decision-making with ecological properties, multi-scalar human drivers, and the legacy effects of past management. Conventional wisdom suggests that resource-intensive turf grass yards are the most common landscaping outcome, resulting in a presumed homogeneous set of residential landscaping practices throughout North America. We examine this homogenization thesis through an interview-based, cross-site study of residential landscape management in Boston, Phoenix, and Miami. Counter to the homogeneity thesis, we find that yard management practices often exhibit heterogeneity, for example, in groundcover choice or use of chemical inputs. The degree of …
Global Production Networks, Relational Proximity, And The Sociospatial Dynamics Of Market Internationalization In Bolivia's Wood Products Sector, James T. Murphy
Global Production Networks, Relational Proximity, And The Sociospatial Dynamics Of Market Internationalization In Bolivia's Wood Products Sector, James T. Murphy
Geography
This article advances conceptualizations of global production networks (GPNs) through an analysis of the relational processes that firms in Bolivia's growing wood products industry use to build ties to international markets. Both large- and small-scale manufacturers are increasingly internationalizing their operations in response to the global demand for tropical hardwoods and decentralization of control over the country's forest resources. These firms use four different types of production networks and networking practices to develop international market ties. Each of these networks is distinguishable by its entry barriers, value-creation possibilities, upgrading strategies, and the cognitive, social, and cultural factors that influence who …
Error Propagation In Raster Data Integration: Impacts On Landscape Composition And Configuration, Zachary J. Christman, John Rogan
Error Propagation In Raster Data Integration: Impacts On Landscape Composition And Configuration, Zachary J. Christman, John Rogan
Geography
Integrating raster-based categorical maps from multiple sources necessitates the transformation of geometric characteristics to compare maps, as in land change analyses. By projecting maps to a new geographic reference framework and scaling pixel values to a new size, distortions of map information are introduced that can affect the proportion and arrangement of thematic classes across the landscape. Using a sample land cover dataset depicting a heterogeneous landscape, this paper examines these impacts using three common raster-based transformation methods and introduces a new vector-based method that minimizes error propagation. While relative class area was best preserved by a nearest-neighbor resampling method, …
Enso And Iod Teleconnections For African Ecosystems: Evidence Of Destructive Interference Between Climate Oscillations, Christopher A. Williams, N. P. Hanan
Enso And Iod Teleconnections For African Ecosystems: Evidence Of Destructive Interference Between Climate Oscillations, Christopher A. Williams, N. P. Hanan
Geography
Rainfall and vegetation across Africa are known to resonate with the coupled ocean-atmosphere phenomena of El Niño Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD). However, the regional-scale implications of sea surface temperature variability for Africa's photosyntheis have received little focused attention, particularly in the case of IOD. Furthermore, studies exploring the interactive effects of ENSO and IOD when coincident are lacking. This analysis uses remotely sensed vegetation change plus a land surface model driven with observed meteorology to investigate how rainfall, vegetation, and photosynthesis across Africa respond to these climate oscillations. In addition to the relatively well-known ENSO …
Paper Fish And Policy Conflict: Catch Shares And Ecosystem-Based Management In Maine’S Groundfishery, Jennifer F. Brewer
Paper Fish And Policy Conflict: Catch Shares And Ecosystem-Based Management In Maine’S Groundfishery, Jennifer F. Brewer
Geography
The National Oceanic and Atmospheric Administration professes support for ecosystembased fisheries management, as mandated by Congress in the Fishery Conservation and Management Act, and as endorsed by the Obama Administration’s national ocean policy. Nonetheless, driving agency policies, including catch shares and fishing quotas, focus principally on individual species, diverting attention from ecosystem considerations such as habitat, migratory patterns, trophic relationships, fishing gear, and firmlevel decision making. Environmental non-governmental organization (ENGO) agendas manifest similar inconsistencies. A case study of Maine’s groundfishery demonstrates implications of this policy conflict at the local level. There, multigenerational fishing villages have historically pursued diversified and adaptive …
Evaluation Of Species Distribution Model Algorithms For Fine-Scale Container-Breeding Mosquito Risk Prediction, C. Khatchikian, Florencia Sangermano, D. Kendell, T. Livdahl
Evaluation Of Species Distribution Model Algorithms For Fine-Scale Container-Breeding Mosquito Risk Prediction, C. Khatchikian, Florencia Sangermano, D. Kendell, T. Livdahl
Geography
The present work evaluates the use of species distribution model (SDM) algorithms to classify high densities of small container-breeding Aedes mosquitoes (Diptera: Culicidae) on a fine scale in the Bermuda Islands. Weekly ovitrap data collected by the Department of Health, Bermuda for the years 2006 and 2007 were used for the models. The models evaluated included the algorithms Bioclim, Domain, GARP (genetic algorithm for rule-set prediction), logistic regression and MaxEnt (maximum entropy). Models were evaluated according to performance and robustness. The area under the receiver operating characteristic curve was used to evaluate each model's performance, and robustness was assessed according …
Death To Kappa: Birth Of Quantity Disagreement And Allocation Disagreement For Accuracy Assessment, Robert Gilmore Pontius, Marco Millones
Death To Kappa: Birth Of Quantity Disagreement And Allocation Disagreement For Accuracy Assessment, Robert Gilmore Pontius, Marco Millones
Geography
The family of Kappa indices of agreement claim to compare a map's observed classification accuracy relative to the expected accuracy of baseline maps that can have two types of randomness: (1) random distribution of the quantity of each category and (2) random spatial allocation of the categories. Use of the Kappa indices has become part of the culture in remote sensing and other fields. This article exam- ines five different Kappa indices, some of which were derived by the first author in 2000. We expose the indices' properties mathematically and illustrate their limitations graphically, with emphasis on Kappa's use of …
Market Intermediaries And Rural People In Bolivia's Forest Products Sector: Are Trusting Partnerships Possible?, James T. Murphy, Mary Lawhon
Market Intermediaries And Rural People In Bolivia's Forest Products Sector: Are Trusting Partnerships Possible?, James T. Murphy, Mary Lawhon
Geography
Decentralization in access to and control of Bolivia's forest resources, coupled with a rising global demand for tropical hardwoods, raises important questions about whether increased trade and community forest management (CFM) initiatives can enable forms of market integration that have more favourable outcomes for rural communities. This paper assesses the prospects for such a transition through an examination of the relationships linking wood product market intermediaries (brokers and buyers) to rural suppliers and forest communities in Bolivia. The analysis centres on whether trust - conceptualized as a power-laden sociospatial process driven by multiscalar factors - can evolve between buyers and …
Does Terrestrial Drought Explain Global Co 2 Flux Anomalies Induced By El Niño?, C. R. Schwalm, Christopher A. Williams, K. Schaefer, I. Baker, G. J. Collatz, C. Rödenbeck
Does Terrestrial Drought Explain Global Co 2 Flux Anomalies Induced By El Niño?, C. R. Schwalm, Christopher A. Williams, K. Schaefer, I. Baker, G. J. Collatz, C. Rödenbeck
Geography
The El Niño Southern Oscillation is the dominant year-to-year mode of global climate variability. El Niño effects on terrestrial carbon cycling are mediated by associated climate anomalies, primarily drought, influencing fire emissions and biotic net ecosystem exchange (NEE). Here we evaluate whether El Niño produces a consistent response from the global carbon cycle. We apply a novel bottom-up approach to estimating global NEE anomalies based on FLUXNET data using land cover maps and weather reanalysis. We analyze 13 years (1997-2009) of globally gridded observational NEE anomalies derived from eddy covariance flux data, remotely-sensed fire emissions at the monthly time step, …
Detection Of The Timing And Duration Of Snowmelt In The Hindu Kush-Himalaya Using Quikscat, 2000-2008, Prajjwal K. Panday, Karen E. Frey, Bardan Ghimire
Detection Of The Timing And Duration Of Snowmelt In The Hindu Kush-Himalaya Using Quikscat, 2000-2008, Prajjwal K. Panday, Karen E. Frey, Bardan Ghimire
Geography
The Hindu Kush-Himalayan (HKH) region holds the largest mass of ice in Central Asia and is highly vulnerable to global climate change, experiencing significant warming (0.21 ± 0.08 °C/decade) over the past few decades. Accurate monitoring of the timing and duration of snowmelt across the HKH region is important, as this region is expected to experience further warming in response to increased greenhouse gas forcing. Despite the many advantages and applications of satellite-derived radar scatterometer data shown for capturing ice and snow melt dynamics at high latitudes, similar comprehensive freeze/thaw detection studies at lower latitudes (including the HKH region) are …
Utilizing Temporally Invariant Calibration Sites To Classify Multiple Dates And Types Of Satellite Imagery, Joe Fortier, John Rogan, Curtis E. Woodcock, Daniel Miller Runfola
Utilizing Temporally Invariant Calibration Sites To Classify Multiple Dates And Types Of Satellite Imagery, Joe Fortier, John Rogan, Curtis E. Woodcock, Daniel Miller Runfola
Geography
Mapping past time periods (retrospective mapping) using remotely sensed data is hindered by a lack of coincident calibration and validation information. The identification of features of same ground cover invariant across time and their use as calibration and validation data addresses this challenge by: (a) streamlining the process of image calibration for multiple dates, and (b) allowing each image to generate its own spectral signature. This study investigates the use of temporally invariant calibration and validation data to map land-cover in Massachusetts, employing five satellite images collected from five separate dates and different sensors. The results indicate that this technique …
Spatial And Interannual Variability Of Dissolved Organic Matter In The Kolyma River, East Siberia, Observed Using Satellite Imagery, Claire G. Griffin, Karen E. Frey, John Rogan, Robert M. Holmes
Spatial And Interannual Variability Of Dissolved Organic Matter In The Kolyma River, East Siberia, Observed Using Satellite Imagery, Claire G. Griffin, Karen E. Frey, John Rogan, Robert M. Holmes
Geography
The Kolyma River basin in northeastern Siberia, the sixth largest river basin draining to the Arctic Ocean, contains vast reserves of carbon in Pleistocene-aged permafrost soils. Permafrost degradation, as a result of climate change, may cause shifts in riverine biogeochemistry as this old source of organic matter is exposed. Satellite remote sensing offers an opportunity to complement and extrapolate field sampling of dissolved organic matter in this expansive and remote region. We develop empirically based algorithms that estimate chromophoric dissolved organic matter (CDOM) and dissolved organic carbon (DOC) in the Kolyma River and its major tributaries in the vicinity of …
Theorizing Practice In Economic Geography: Foundations, Challenges, And Possibilities, Andrew Jones, James T. Murphy
Theorizing Practice In Economic Geography: Foundations, Challenges, And Possibilities, Andrew Jones, James T. Murphy
Geography
Over the last decade or so there has been an identifiable shift in the interests of many economic geographers towards a concern with practices: stabilized, routinized, or improvised social actions that constitute and reproduce economic space, and through and within which socioeconomic actors and communities embed knowledge, organize production activities, and interpret and derive meaning from the world. Although this shift has gained significant momentum its general theoretical significance remains somewhat unclear and the concept is vulnerable to criticisms that it is incoherent, too 'micro-scale' in emphasis, unable to provide valid links between everyday practices and higher-order phenomena (eg, institutions, …
Climate Change: Helping Nature Survive The Human Response, Will R. Turner, Bethany A. Bradley, Lyndon D. Estes, David G. Hole, Michael Oppenheimer, David S. Wilcove
Climate Change: Helping Nature Survive The Human Response, Will R. Turner, Bethany A. Bradley, Lyndon D. Estes, David G. Hole, Michael Oppenheimer, David S. Wilcove
Geography
Climate change poses profound, direct, and well-documented threats to biodiversity. A significant fraction of Earth's species is at risk of extinction due to changing precipitation and temperature regimes, rising and acidifying oceans, and other factors. There is also growing awareness of the diversity and magnitude of responses, both proactive and reactive, that people will undertake as lives and livelihoods are affected by climate change. Yet to date few studies have examined the relationship between these two powerful forces. The natural systems upon which people depend, already under direct assault from climate change, are further threatened by how we respond to …
Polycentrism And Flux In Spatialized Management: Evidence From Maine's Lobster (Homarus Americanus) Fishery, Jennifer F. Brewer
Polycentrism And Flux In Spatialized Management: Evidence From Maine's Lobster (Homarus Americanus) Fishery, Jennifer F. Brewer
Geography
Spatial approaches to fisheries management hold great promise but require continued conceptual and policy development. Polycentrism and flux emerge as useful concepts, drawing lessons from more customary, informal resourceuse patterns to produce more innovative “spatialized” policies within existing governance architectures. Empirical evidence from Maine shows that pioneering efforts have been limited by the single-species focus of conventional management hierarchies. As entry limits have consolidated the fishing fleet and eliminated flexible, diversified, and adaptive business strategies, cross-species and habitat externalities have become problematic. State lobster (Homarus americanus Milne- Edwards, 1837) comanagement zones have achieved some successes, including trap limits and improved …
Climate Control Of Terrestrial Carbon Exchange Across Biomes And Continents, Chuixiang Yi, Runze Li, John Wolbeck, Xiyan Xu, Mats Nilsson, Luis Aires, John D. Albertson, Christof Ammann, M. Altaf Arain, Alessandro C. De Araujo, Marc Aubinet, Mika Aurela, Zoltán Barcza, Alan Barr, Paul Berbigier, Jason Beringer, Christian Bernhofer, Andrew T. Black, Paul V. Bolstad, Fred C. Bosveld, Mark S.J. Broadmeadow, Nina Buchmann, Sean P. Burns, Pierre Cellier, Jingming Chen, Jiquan Chen, Philippe Ciais, Robert Clement, Bruce D. Cook, Peter S. Curtis, D. Bryan Dail, Ebba Dellwik, Christopher A. Williams
Climate Control Of Terrestrial Carbon Exchange Across Biomes And Continents, Chuixiang Yi, Runze Li, John Wolbeck, Xiyan Xu, Mats Nilsson, Luis Aires, John D. Albertson, Christof Ammann, M. Altaf Arain, Alessandro C. De Araujo, Marc Aubinet, Mika Aurela, Zoltán Barcza, Alan Barr, Paul Berbigier, Jason Beringer, Christian Bernhofer, Andrew T. Black, Paul V. Bolstad, Fred C. Bosveld, Mark S.J. Broadmeadow, Nina Buchmann, Sean P. Burns, Pierre Cellier, Jingming Chen, Jiquan Chen, Philippe Ciais, Robert Clement, Bruce D. Cook, Peter S. Curtis, D. Bryan Dail, Ebba Dellwik, Christopher A. Williams
Geography
Understanding the relationships between climate and carbon exchange by terrestrial ecosystems is critical to predict future levels of atmospheric carbon dioxide because of the potential accelerating effects of positive climate-carbon cycle feedbacks. However, directly observed relationships between climate and terrestrial CO2exchange with the atmosphere across biomes and continents are lacking. Here we present data describing the relationships between net ecosystem exchange of carbon (NEE) and climate factors as measured using the eddy covariance method at 125 unique sites in various ecosystems over six continents with a total of 559 site-years. We find that NEE observed at eddy covariance sites is …
Complexity In Water And Carbon Dioxide Fluxes Following Rain Pulses In An African Savanna, Christopher A. Williams, Niall Hanan, Robert J. Scholes, Werner Kutsch
Complexity In Water And Carbon Dioxide Fluxes Following Rain Pulses In An African Savanna, Christopher A. Williams, Niall Hanan, Robert J. Scholes, Werner Kutsch
Geography
The idea that many processes in arid and semi-arid ecosystems are dormant until activated by a pulse of rainfall, and then decay from a maximum rate as the soil dries, is widely used as a conceptual and mathematical model, but has rarely been evaluated with data. This paper examines soil water, evapotranspiration (ET), and net ecosystem CO2 exchange measured for 5 years at an eddy covariance tower sited in an Acacia-Combretum savanna near Skukuza in the Kruger National Park, South Africa. The analysis characterizes ecosystem flux responses to discrete rain events and evaluates the skill of increasingly complex "pulse models". …
Drivers Of Inter-Annual Variability In Net Ecosystem Exchange In A Semi-Arid Savanna Ecosystem, South Africa, S. A. Archibald, A. Kirton, M. R. Van Der Merwe, R. J. Scholes, Christopher A. Williams, N. Hanan
Drivers Of Inter-Annual Variability In Net Ecosystem Exchange In A Semi-Arid Savanna Ecosystem, South Africa, S. A. Archibald, A. Kirton, M. R. Van Der Merwe, R. J. Scholes, Christopher A. Williams, N. Hanan
Geography
Inter-annual variability in primary production and ecosystem respiration was explored using eddy-covariance data at a semi-arid savanna site in the Kruger Park, South Africa. New methods of extrapolating night-time respiration to the entire day and filling gaps in eddy-covariance data in semi-arid systems were developed. Net ecosystem exchange (NEE) in these systems occurs as pulses associated with rainfall events, a pattern not well-represented in current standard gap-filling procedures developed primarily for temperate flux sites. They furthermore do not take into account the decrease in respiration at high soil temperatures. An artificial neural network (ANN) model incorporating these features predicted measured …
The World Development Report 2009 'Reshapes Economic Geography': Geographical Reflections, Jonathan Rigg, Anthony J. Bebbington, Katherine V. Gough, Deborah F. Bryceson, Jytte Agergaard, Niels Fold, Cecilia Tacoli
The World Development Report 2009 'Reshapes Economic Geography': Geographical Reflections, Jonathan Rigg, Anthony J. Bebbington, Katherine V. Gough, Deborah F. Bryceson, Jytte Agergaard, Niels Fold, Cecilia Tacoli
Geography
The Report focuses on the spatial transformations that must happen for countries to develop. Cities, migration and trade, it is claimed, have been the main catalysts of progress and hence ‗Growing cities, ever more mobile people, and increasingly specialised products are … essential for economic success‘ (World Bank 2009, xx). These greater densities, shorter distances and reduced divisions will, the Report argues, bring about unbalanced growth: however, over time, other policies and mechanisms for integration will foster convergence in living standards. Development, seen through the Report‘s eyes, involves a necessary (and welcome) spatial unevenness in economic activity coupled with progressive …
Latin America: Contesting Extraction, Producing Geographies, Anthony J. Bebbington
Latin America: Contesting Extraction, Producing Geographies, Anthony J. Bebbington
Geography
Characterizing continents is the business of fools, inviting the charge of essentialization, over-generalization, and caricature of nuanced and complex processes varying across space and over time. Likewise it can attract the criticism that to privilege the national or the regional understates the transnational dimensions of social change, and to take a territorialized view diverts attention from the networks that cut across space, linking distant actors and places. This short essay therefore claims neither to be a reflection on Latin America-wide phenomena, and far less a statement on the most significant aspects of the political economy of the region. It does, …