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• 1. [Article] Forest Resource Use, Land-Use, and Ecotourism in the Río Plátano Biosphere Reserve, Honduras

  The Río Pláttano Biosphere Reserve, a tropical rainforest reserve in the northeastern corner of Honduras, is home to several subsistence-based indigenous groups, including the Miskito, Pech and Garifuna, ...

  Citation × Citation Citation Abstract Copy Title: Forest Resource Use, Land-Use, and Ecotourism in the Río Plátano Biosphere Reserve, Honduras Author: Friedle, Christina Marie Year: 2005 The Río Pláttano Biosphere Reserve, a tropical rainforest reserve in the northeastern corner of Honduras, is home to several subsistence-based indigenous groups, including the Miskito, Pech and Garifuna, as well as the non-indigenous Ladinos. Communities within the reserve depend on forest resources, swidden agriculture, marine resources and/or small-scale ranching as the foundations for local economies. Regulations placed on these subsistence practices, after establishment of the biosphere reserve in 1980, have created unique and new pressures and resulted in a blend of traditional and innovative resource use. A notable result is the promotion of ecotourism as a solution for meeting the economic needs of local populations while conserving local resources. This thesis documents current resource use in the Miskito and Ladino communities of Banaka, Brans, and Fuente de Jacob, in the Río Pláttano Biosphere Reserve and the potential of ecotourism to maintain both local economies and consumption of tropical rainforest resources in these communities. Analysis suggests that a community-based approach to ecotourism can result in economic benefits and maintain local culture. This thesis documents current resource use (agricultural crops and trees, gathered and cultivated plants, tree-use, and hunting), resident perspectives on ecotourism development and industry, and provides the foundation for long-term monitoring and analysis on the effects of ecotomism on forest resource and land-use in the greater Banaka region. Title: Forest Resource Use, Land-Use, and Ecotourism in the Río Plátano Biosphere Reserve, Honduras Author: Friedle, Christina Marie Year: 2005 The Río Pláttano Biosphere Reserve, a tropical rainforest reserve in the northeastern corner of Honduras, is home to several subsistence-based indigenous groups, including the Miskito, Pech and Garifuna, as well as the non-indigenous Ladinos. Communities within the reserve depend on forest resources, swidden agriculture, marine resources and/or small-scale ranching as the foundations for local economies. Regulations placed on these subsistence practices, after establishment of the biosphere reserve in 1980, have created unique and new pressures and resulted in a blend of traditional and innovative resource use. A notable result is the promotion of ecotourism as a solution for meeting the economic needs of local populations while conserving local resources. This thesis documents current resource use in the Miskito and Ladino communities of Banaka, Brans, and Fuente de Jacob, in the Río Pláttano Biosphere Reserve and the potential of ecotourism to maintain both local economies and consumption of tropical rainforest resources in these communities. Analysis suggests that a community-based approach to ecotourism can result in economic benefits and maintain local culture. This thesis documents current resource use (agricultural crops and trees, gathered and cultivated plants, tree-use, and hunting), resident perspectives on ecotourism development and industry, and provides the foundation for long-term monitoring and analysis on the effects of ecotomism on forest resource and land-use in the greater Banaka region. Close

• 2. [Article] Determinants of the Spatial Distribution of Peri-Urban to Rural Agriculture in the United States

  Two issues are focal to the subject of the spatial distribution of crops in peri-urban zones. The first deals with developments in the fields of transportation, other technology, urbanization, and other ...

  Citation × Citation Citation Abstract Copy Title: Determinants of the Spatial Distribution of Peri-Urban to Rural Agriculture in the United States Author: Abdel-Karim, Ibrahim Amin Year: 1987 Two issues are focal to the subject of the spatial distribution of crops in peri-urban zones. The first deals with developments in the fields of transportation, other technology, urbanization, and other factors which are not only prevalent in developed world economies, but which also are thought to force the cultivation of freshly consumed agricultural commodities away from the immediate vicinity of the market center. The second issue pertains to indirectly consumed crops, which are thought to shun proximity to the market center, where land rents per unit area are characteristically high, even when conditions for productions are ideal. Traditional models have shown a zonal pattern of crop distribution in peri-urban areas. The present study sets forth two hypotheses, one pertaining to the spatial distribution of freshly consumed crops, and the other pertaining to the spatial distribution of indirectly consumed crops. It was hypothesized in the present study that freshly consumed crops will continue to be cultivated in the near vicinity of the market center due to characteristics of the crops and the urban market. It was further hypothesized that indirectly consumed crops will continue to be cultivated in the near vicinity of the market center by virtue of greater intensity of production that may be obtained through the use of the environment of designated places. In the case of both crops, the cited factors, as well as others, offset the disadvantages of higher land rent per unit area common to areas close to the market center. These offsetting factors permit agriculture to compete successfully for land in the peri-urban zone. To test these hypotheses, variables were selected to measure the influence that urbanization, transportation, other technologies, the market, the environment, and land use regulations have on agricultural siting patterns in the peri-urban zones of the "Wheat Region" of the central United States. These variables were expressed as equations and were subjected to multiple linear regression (MLR) analysis. The present findings tended to support the research hypotheses. On the basis of these findings, the present research offers a revised model of agricultural cropping patterns, one that reflects the sectoral, rather than the zonal, pattern of crop distribution in peri-urban zones. In the revised model, the mixing of different crops at various locations around the market is feasible, and low-priced grains may compete successfully for high-rent locations in the near vicinity of the urban market. The findings also show that the production of perishable crops in the iIl'.mediate vicinity of the urban market is here to stay, largely due to access to varied means of transportation as well as characteristics of the crops themselves. Furthermore, the findings show that environmental conditions influence the locating of grain production, although economic considerations were seen to supersede them, particularly at high-rent sites. Title: Determinants of the Spatial Distribution of Peri-Urban to Rural Agriculture in the United States Author: Abdel-Karim, Ibrahim Amin Year: 1987 Two issues are focal to the subject of the spatial distribution of crops in peri-urban zones. The first deals with developments in the fields of transportation, other technology, urbanization, and other factors which are not only prevalent in developed world economies, but which also are thought to force the cultivation of freshly consumed agricultural commodities away from the immediate vicinity of the market center. The second issue pertains to indirectly consumed crops, which are thought to shun proximity to the market center, where land rents per unit area are characteristically high, even when conditions for productions are ideal. Traditional models have shown a zonal pattern of crop distribution in peri-urban areas. The present study sets forth two hypotheses, one pertaining to the spatial distribution of freshly consumed crops, and the other pertaining to the spatial distribution of indirectly consumed crops. It was hypothesized in the present study that freshly consumed crops will continue to be cultivated in the near vicinity of the market center due to characteristics of the crops and the urban market. It was further hypothesized that indirectly consumed crops will continue to be cultivated in the near vicinity of the market center by virtue of greater intensity of production that may be obtained through the use of the environment of designated places. In the case of both crops, the cited factors, as well as others, offset the disadvantages of higher land rent per unit area common to areas close to the market center. These offsetting factors permit agriculture to compete successfully for land in the peri-urban zone. To test these hypotheses, variables were selected to measure the influence that urbanization, transportation, other technologies, the market, the environment, and land use regulations have on agricultural siting patterns in the peri-urban zones of the "Wheat Region" of the central United States. These variables were expressed as equations and were subjected to multiple linear regression (MLR) analysis. The present findings tended to support the research hypotheses. On the basis of these findings, the present research offers a revised model of agricultural cropping patterns, one that reflects the sectoral, rather than the zonal, pattern of crop distribution in peri-urban zones. In the revised model, the mixing of different crops at various locations around the market is feasible, and low-priced grains may compete successfully for high-rent locations in the near vicinity of the urban market. The findings also show that the production of perishable crops in the iIl'.mediate vicinity of the urban market is here to stay, largely due to access to varied means of transportation as well as characteristics of the crops themselves. Furthermore, the findings show that environmental conditions influence the locating of grain production, although economic considerations were seen to supersede them, particularly at high-rent sites. Close

• 3. [Article] Agricultural Management Decisions Impact Isoprene Emission and Physiology of Arundo donax, an Emerging Bioenergy Crop

  Arundo donax (Giant Reed) is quickly being developed as a rapidly-growing, robust, and highly productive bioenergy crop, with large scale cultivation of this species planned for the Columbia River basin ...

  Citation × Citation Citation Abstract Copy Title: Agricultural Management Decisions Impact Isoprene Emission and Physiology of Arundo donax, an Emerging Bioenergy Crop Author: Maxfield, Jason Charles Year: 2014 Arundo donax (Giant Reed) is quickly being developed as a rapidly-growing, robust, and highly productive bioenergy crop, with large scale cultivation of this species planned for the Columbia River basin of the Pacific Northwest (USA). Despite its potential as a next generation biomass crop, relatively few studies have examined the physiological performance of A. donax under agricultural conditions. Unlike traditional crops, A. donax is known to be a high-emitter of the volatile compound isoprene, which may significantly impact regional air quality, but it has not been widely cultivated in North America and little is known about how this species will perform in the Pacific Northwest. Over two field seasons, we measured isoprene fluxes from A. donax plants in both greenhouse conditions and in an agricultural field setting under a variety of conditions and fertilizer treatments. We also measured several other attributes of A. donax productivity and leaf physiology including chlorophyll content, photosynthesis rate, stomatal conductance, specific leaf mass, water use efficiency and gas exchange. We found that A. donax physiologically performs well under cultivation in the Columbia River basin, but that it also emits isoprene at significantly higher rates than previous reports indicate. We also found that both isoprene emission and leaf physiology were highly affected by agricultural management decisions, including nitrogen and irrigation management. Our findings indicate that crop management strategies can be developed that simultaneously seek to minimize isoprene emission while maximizing biomass production in this newly emerging bioenergy crop. Title: Agricultural Management Decisions Impact Isoprene Emission and Physiology of Arundo donax, an Emerging Bioenergy Crop Author: Maxfield, Jason Charles Year: 2014 Arundo donax (Giant Reed) is quickly being developed as a rapidly-growing, robust, and highly productive bioenergy crop, with large scale cultivation of this species planned for the Columbia River basin of the Pacific Northwest (USA). Despite its potential as a next generation biomass crop, relatively few studies have examined the physiological performance of A. donax under agricultural conditions. Unlike traditional crops, A. donax is known to be a high-emitter of the volatile compound isoprene, which may significantly impact regional air quality, but it has not been widely cultivated in North America and little is known about how this species will perform in the Pacific Northwest. Over two field seasons, we measured isoprene fluxes from A. donax plants in both greenhouse conditions and in an agricultural field setting under a variety of conditions and fertilizer treatments. We also measured several other attributes of A. donax productivity and leaf physiology including chlorophyll content, photosynthesis rate, stomatal conductance, specific leaf mass, water use efficiency and gas exchange. We found that A. donax physiologically performs well under cultivation in the Columbia River basin, but that it also emits isoprene at significantly higher rates than previous reports indicate. We also found that both isoprene emission and leaf physiology were highly affected by agricultural management decisions, including nitrogen and irrigation management. Our findings indicate that crop management strategies can be developed that simultaneously seek to minimize isoprene emission while maximizing biomass production in this newly emerging bioenergy crop. Close

• 4. [Article] The effect of human activity on the middle course of the Tualatin River, Oregon

  A diurnal study of biological, chemical, and physical parameters was made on the middle course of the, Tualatin River, which drains a 1840 km2 (711 mi2) basin adjacent to metropolitan Portland, Oregon. ...

  Citation × Citation Citation Abstract Copy Title: The effect of human activity on the middle course of the Tualatin River, Oregon Author: Carter, Lolita M. Year: 1975 A diurnal study of biological, chemical, and physical parameters was made on the middle course of the, Tualatin River, which drains a 1840 km2 (711 mi2) basin adjacent to metropolitan Portland, Oregon. This portion of the river lies along land in transition of use from rural agriculture to highly urbanized development. There is no nutrient loading of the river from farming practices because there was no return of water from summer, sprinkler irrigation of commercial crops. However, irrigation significantly reduces the volume of water in the river in the summers. Effluents from sewage treatment plants flowing into the tributaries that drain the highly urbanized eastern areas of the river basin are the main cause of degraded water quality and algal biomass in the lower reaches of the river. The Tualatin River above the mouth of Rock Creek is relatively unpolluted, but downstream from Rock Creek the river is highly eutrophic and during the periods of low flow in the summer serves as a sewage oxidation channel. In this same portion of the river there is also evidence that nitrification occurs. Winter floods leach nitrate-nitrogen from the basin, but in the summer the possibility exists. that nitrate-nitrogen may be a limiting nutrient for algal productivity in the river above Hillsboro. The principal source of poly-phosphates is from sewage treatment plant effluents, but concentrations of poly-phosphates in the middle reaches of the river indicate that there is a natural source of poly- and/or ortho-phosphates in the watershed. Removal of phosphorous compounds from the effluents probably would not affect the large algal blooms occurring in the river below Hillsboro. Trace metal analyses indicated that iron, potassium, nickel, zinc, lead, copper, cobalt, and chromium concentrations were higher during flooding. Turbidity readings suggest that these trace elements are deposited on the floodplain. Melted snow water, which caused one of the winter floods, contained concentrations of zinc, ·copper, and lead greater than those found in the river during the flood. Greater concentrations of arsenic and zinc came from farmland than from urban areas. Diversities of the net plankton as measured by the Shannon-Weaver Index did not change from season to season, nor with downstream flow. Species in the net plankton were benthic forms at the upper stations and planktonic forms downstream from Hillsboro, especially in the summer when the reduced flow caused the river to pond. The enriched effluents from Rock Creek did not affect the diversity of the organisms downstream, but supported a larger biomass. By rating the diversities with other studies it was found that the middle course of the Tualatin River is eutrophic but not heavily polluted. A diurnal study was especially valuable from April to September, inclusive, when insolation and temperatures favored biological activities such as photosynthesis and decomposition. From November to January little diurnal change in the water quality was found. Farming had its greatest impact in the quantity of water and municipalities had a more serious impact on the water quality in the middle course of the Tualatin River. Even with the reduced flow from agricultural irrigation, the river can maintain relatively good water quality, except when effluents from sewage plants caused highly eutrophic conditions. Title: The effect of human activity on the middle course of the Tualatin River, Oregon Author: Carter, Lolita M. Year: 1975 A diurnal study of biological, chemical, and physical parameters was made on the middle course of the, Tualatin River, which drains a 1840 km2 (711 mi2) basin adjacent to metropolitan Portland, Oregon. This portion of the river lies along land in transition of use from rural agriculture to highly urbanized development. There is no nutrient loading of the river from farming practices because there was no return of water from summer, sprinkler irrigation of commercial crops. However, irrigation significantly reduces the volume of water in the river in the summers. Effluents from sewage treatment plants flowing into the tributaries that drain the highly urbanized eastern areas of the river basin are the main cause of degraded water quality and algal biomass in the lower reaches of the river. The Tualatin River above the mouth of Rock Creek is relatively unpolluted, but downstream from Rock Creek the river is highly eutrophic and during the periods of low flow in the summer serves as a sewage oxidation channel. In this same portion of the river there is also evidence that nitrification occurs. Winter floods leach nitrate-nitrogen from the basin, but in the summer the possibility exists. that nitrate-nitrogen may be a limiting nutrient for algal productivity in the river above Hillsboro. The principal source of poly-phosphates is from sewage treatment plant effluents, but concentrations of poly-phosphates in the middle reaches of the river indicate that there is a natural source of poly- and/or ortho-phosphates in the watershed. Removal of phosphorous compounds from the effluents probably would not affect the large algal blooms occurring in the river below Hillsboro. Trace metal analyses indicated that iron, potassium, nickel, zinc, lead, copper, cobalt, and chromium concentrations were higher during flooding. Turbidity readings suggest that these trace elements are deposited on the floodplain. Melted snow water, which caused one of the winter floods, contained concentrations of zinc, ·copper, and lead greater than those found in the river during the flood. Greater concentrations of arsenic and zinc came from farmland than from urban areas. Diversities of the net plankton as measured by the Shannon-Weaver Index did not change from season to season, nor with downstream flow. Species in the net plankton were benthic forms at the upper stations and planktonic forms downstream from Hillsboro, especially in the summer when the reduced flow caused the river to pond. The enriched effluents from Rock Creek did not affect the diversity of the organisms downstream, but supported a larger biomass. By rating the diversities with other studies it was found that the middle course of the Tualatin River is eutrophic but not heavily polluted. A diurnal study was especially valuable from April to September, inclusive, when insolation and temperatures favored biological activities such as photosynthesis and decomposition. From November to January little diurnal change in the water quality was found. Farming had its greatest impact in the quantity of water and municipalities had a more serious impact on the water quality in the middle course of the Tualatin River. Even with the reduced flow from agricultural irrigation, the river can maintain relatively good water quality, except when effluents from sewage plants caused highly eutrophic conditions. Close

• 5. [Article] Evidence of reduced arbuscular mycorrhizal fungal colonization in multiple lines of Bt maize

  Premise of the Study: Insect-resistant Bacillus thuringiensis (Bt) maize is widely cultivated, yet few studies have examined the interaction of symbiotic arbuscular mycorrhizal fungi (AMF) with different ...

  Citation × Citation Citation Abstract Copy Title: Evidence of reduced arbuscular mycorrhizal fungal colonization in multiple lines of Bt maize Author: Cheeke, Tanya E., Rosenstiel, Todd N., Cruzan, Mitchell B. Year: 2012 Premise of the Study: Insect-resistant Bacillus thuringiensis (Bt) maize is widely cultivated, yet few studies have examined the interaction of symbiotic arbuscular mycorrhizal fungi (AMF) with different lines of Bt maize. As obligate symbionts, AMF may be sensitive to genetic changes within a plant host. Previous evaluations of the impact of Bt crops on AMF have been inconsistent, and because most studies were conducted under disparate experimental conditions, the results are difficult to compare. Methods: We evaluate AMF colonization in nine Bt maize lines, differing in number and type of engineered trait, and five corresponding near-isogenic parental (P) base hybrids in greenhouse microcosms. Plants were grown in 50% local agricultural soil with low levels of fertilization, and AMF colonization was evaluated at 60 and 100 d. Nontarget effects of Bt cultivation on AMF colonization were tested in a subsequently planted crop, Glycine max, which was seeded into soil that had been preconditioned for 60 d with Bt or P maize. Key Results: We found that Bt maize had lower levels of AMF colonization in their roots than did the non-Bt parental lines. However, reductions in AMF colonization were not related to the expression of a particular Bt protein. There was no difference in AMF colonization in G. max grown in the Bt- or P-preconditioned soil. Conclusions: These findings are the first demonstration of a reduction in AMF colonization in multiple Bt maize lines grown under the same experimental conditions and contribute to the growing body of knowledge examining the unanticipated effects of Bt crop cultivation on nontarget soil organisms. Title: Evidence of reduced arbuscular mycorrhizal fungal colonization in multiple lines of Bt maize Author: Cheeke, Tanya E., Rosenstiel, Todd N., Cruzan, Mitchell B. Year: 2012 Premise of the Study: Insect-resistant Bacillus thuringiensis (Bt) maize is widely cultivated, yet few studies have examined the interaction of symbiotic arbuscular mycorrhizal fungi (AMF) with different lines of Bt maize. As obligate symbionts, AMF may be sensitive to genetic changes within a plant host. Previous evaluations of the impact of Bt crops on AMF have been inconsistent, and because most studies were conducted under disparate experimental conditions, the results are difficult to compare. Methods: We evaluate AMF colonization in nine Bt maize lines, differing in number and type of engineered trait, and five corresponding near-isogenic parental (P) base hybrids in greenhouse microcosms. Plants were grown in 50% local agricultural soil with low levels of fertilization, and AMF colonization was evaluated at 60 and 100 d. Nontarget effects of Bt cultivation on AMF colonization were tested in a subsequently planted crop, Glycine max, which was seeded into soil that had been preconditioned for 60 d with Bt or P maize. Key Results: We found that Bt maize had lower levels of AMF colonization in their roots than did the non-Bt parental lines. However, reductions in AMF colonization were not related to the expression of a particular Bt protein. There was no difference in AMF colonization in G. max grown in the Bt- or P-preconditioned soil. Conclusions: These findings are the first demonstration of a reduction in AMF colonization in multiple Bt maize lines grown under the same experimental conditions and contribute to the growing body of knowledge examining the unanticipated effects of Bt crop cultivation on nontarget soil organisms. Close

• 6. [Article] Field Evaluation of Arbuscular Mycorrhizal Fungal Colonization in Bacillus thuringiensis Toxin-Expressing (Bt) and Non-Bt Maize

  The cultivation of genetically engineered Bacillus thuringiensis toxin-expressing (Bt) maize continues to increase worldwide, yet the effects of Bt crops on arbuscular mycorrhizal fungi (AMF) in soil are ...

  Citation × Citation Citation Abstract Copy Title: Field Evaluation of Arbuscular Mycorrhizal Fungal Colonization in Bacillus thuringiensis Toxin-Expressing (Bt) and Non-Bt Maize Author: Cheeke, Tanya E., Cruzan, Mitchell B., Rosenstiel, Todd N. Year: 2013 The cultivation of genetically engineered Bacillus thuringiensis toxin-expressing (Bt) maize continues to increase worldwide, yet the effects of Bt crops on arbuscular mycorrhizal fungi (AMF) in soil are poorly understood. In this field experiment, we investigated the impact of seven different genotypes of Bt maize and five corresponding non-Bt parental cultivars on AMF and evaluated plant growth responses at three different physiological time points. Plants were harvested 60 days (active growth), 90 days (tasseling and starting to produce ears), and 130 days (maturity) after sowing, and data on plant growth responses and percent AMF colonization of roots at each harvest were collected. Spore abundance and diversity were also evaluated at the beginning and end of the field season to determine whether the cultivation of Bt maize had a negative effect on AMF propagules in the soil. Plant growth and AMF colonization did not differ between Bt and non-Bt maize at any harvest period, but AMF colonization was positively correlated with leaf chlorophyll content at the 130-day harvest. Cultivation of Bt maize had no effect on spore abundance and diversity in Bt versus non-Bt plots over one field season. Plot had the most significant effect on total spore counts, indicating spatial heterogeneity in the field. Although previous greenhouse studies demonstrated that AMF colonization was lower in some Bt maize lines, our field study did not yield the same results, suggesting that the cultivation of Bt maize may not have an impact on AMF in the soil ecosystem under field conditions. Title: Field Evaluation of Arbuscular Mycorrhizal Fungal Colonization in Bacillus thuringiensis Toxin-Expressing (Bt) and Non-Bt Maize Author: Cheeke, Tanya E., Cruzan, Mitchell B., Rosenstiel, Todd N. Year: 2013 The cultivation of genetically engineered Bacillus thuringiensis toxin-expressing (Bt) maize continues to increase worldwide, yet the effects of Bt crops on arbuscular mycorrhizal fungi (AMF) in soil are poorly understood. In this field experiment, we investigated the impact of seven different genotypes of Bt maize and five corresponding non-Bt parental cultivars on AMF and evaluated plant growth responses at three different physiological time points. Plants were harvested 60 days (active growth), 90 days (tasseling and starting to produce ears), and 130 days (maturity) after sowing, and data on plant growth responses and percent AMF colonization of roots at each harvest were collected. Spore abundance and diversity were also evaluated at the beginning and end of the field season to determine whether the cultivation of Bt maize had a negative effect on AMF propagules in the soil. Plant growth and AMF colonization did not differ between Bt and non-Bt maize at any harvest period, but AMF colonization was positively correlated with leaf chlorophyll content at the 130-day harvest. Cultivation of Bt maize had no effect on spore abundance and diversity in Bt versus non-Bt plots over one field season. Plot had the most significant effect on total spore counts, indicating spatial heterogeneity in the field. Although previous greenhouse studies demonstrated that AMF colonization was lower in some Bt maize lines, our field study did not yield the same results, suggesting that the cultivation of Bt maize may not have an impact on AMF in the soil ecosystem under field conditions. Close

• 7. [Article] Avian population trends within the evolving agricultural landscape of the eastern and central United States

  State-level Breeding Bird Survey (1980-1998) and U.S. Department of Agriculture statistics were used to test the hypothesis that changes in agricultural land use within the eastern and central U.S. have ...

  Citation × Citation Citation Abstract Copy Title: Avian population trends within the evolving agricultural landscape of the eastern and central United States Author: Murphy, Michael T. Year: 2003 State-level Breeding Bird Survey (1980-1998) and U.S. Department of Agriculture statistics were used to test the hypothesis that changes in agricultural land use within the eastern and central U.S. have driven population trends of grassland and shrub habitat birds over the past two decades. The degree to which population trends differed between grassland and shrub habitats was evaluated with respect to migratory and nesting behavior. Grassland birds declined significantly between 1980 and 1999, but, on average, shrub habitat species did not. Grassland-breeding, long-distance migrants exhibited the strongest negative trends. Most species (78%; n = 63) exhibited at least one significant association between population trends and changes in agricultural land use, and in most, land use "explained" 25-30% of the variation in population trends among states. Changes in the farmland landscape accounted for more of the interstate variability of population trends of short-distance migrants than of both long-distance migrants and residents, and that variability was greater in grassland than shrub species. Declines in the area of rangeland and cover crops were followed by population declines and increases, respectively, by many species. Increases of land in the Conservation Reserve Program had negative associations with population trends of some shrub species. The results indicate that grassland birds have declined strongly over the past two decades, and that regardless of migratory behavior or nesting habits, avian population trends are linked strongly to changes in agricultural land use within North America. Title: Avian population trends within the evolving agricultural landscape of the eastern and central United States Author: Murphy, Michael T. Year: 2003 State-level Breeding Bird Survey (1980-1998) and U.S. Department of Agriculture statistics were used to test the hypothesis that changes in agricultural land use within the eastern and central U.S. have driven population trends of grassland and shrub habitat birds over the past two decades. The degree to which population trends differed between grassland and shrub habitats was evaluated with respect to migratory and nesting behavior. Grassland birds declined significantly between 1980 and 1999, but, on average, shrub habitat species did not. Grassland-breeding, long-distance migrants exhibited the strongest negative trends. Most species (78%; n = 63) exhibited at least one significant association between population trends and changes in agricultural land use, and in most, land use "explained" 25-30% of the variation in population trends among states. Changes in the farmland landscape accounted for more of the interstate variability of population trends of short-distance migrants than of both long-distance migrants and residents, and that variability was greater in grassland than shrub species. Declines in the area of rangeland and cover crops were followed by population declines and increases, respectively, by many species. Increases of land in the Conservation Reserve Program had negative associations with population trends of some shrub species. The results indicate that grassland birds have declined strongly over the past two decades, and that regardless of migratory behavior or nesting habits, avian population trends are linked strongly to changes in agricultural land use within North America. Close

• 8. [Article] Agricultural Classification of Multi-Temporal MODIS Imagery in Northwest Argentina Using Kansas Crop Phenologies

  Subtropical deforestation in Latin America is thought to be driven by demand for agricultural land, particularly to grow soybeans. However, existing remote sensing methods that can differentiate crop types ...

  Citation × Citation Citation Abstract Copy Title: Agricultural Classification of Multi-Temporal MODIS Imagery in Northwest Argentina Using Kansas Crop Phenologies Author: Keifer, Jarrett Alexander Year: 2014 Subtropical deforestation in Latin America is thought to be driven by demand for agricultural land, particularly to grow soybeans. However, existing remote sensing methods that can differentiate crop types to verify this hypothesis require high spatial or spectral resolution data, or extensive ground truth information to develop training sites, none of which are freely available for much of the world. I developed a new method of crop classification based on the phenological signatures of crops extracted from multi-temporal MODIS vegetation indices. I tested and refined this method using the USDA Cropland Data Layer from Kansas, USA as a reference. I then applied the method to classify crop types for a study site in Pellegrini, Santiago Del Estero, Argentina. The results show that this method is unable to effectively separate summer crops in Pellegrini, but can differentiate summer crops and non-summer crops. Unmet assumptions about agricultural practices are primarily responsible for the ineffective summer crop classification, underlining the need for researchers to have a complete understanding of ground conditions when designing a remote sensing analysis. Title: Agricultural Classification of Multi-Temporal MODIS Imagery in Northwest Argentina Using Kansas Crop Phenologies Author: Keifer, Jarrett Alexander Year: 2014 Subtropical deforestation in Latin America is thought to be driven by demand for agricultural land, particularly to grow soybeans. However, existing remote sensing methods that can differentiate crop types to verify this hypothesis require high spatial or spectral resolution data, or extensive ground truth information to develop training sites, none of which are freely available for much of the world. I developed a new method of crop classification based on the phenological signatures of crops extracted from multi-temporal MODIS vegetation indices. I tested and refined this method using the USDA Cropland Data Layer from Kansas, USA as a reference. I then applied the method to classify crop types for a study site in Pellegrini, Santiago Del Estero, Argentina. The results show that this method is unable to effectively separate summer crops in Pellegrini, but can differentiate summer crops and non-summer crops. Unmet assumptions about agricultural practices are primarily responsible for the ineffective summer crop classification, underlining the need for researchers to have a complete understanding of ground conditions when designing a remote sensing analysis. Close

• 9. [Article] Beyond Sustainable Bounds: Changing Weather, Emigration, and Irrigation in a Farming Village of Sichuan, China, 1945-2012

  This thesis presents the results of research in a small village located in the mountains of Sichuan Province in southwestern China. The thesis argues that traditional irrigation practices vital to paddy-rice ...

  Citation × Citation Citation Abstract Copy Title: Beyond Sustainable Bounds: Changing Weather, Emigration, and Irrigation in a Farming Village of Sichuan, China, 1945-2012 Author: Parker, Joseph Lynn Year: 2013 This thesis presents the results of research in a small village located in the mountains of Sichuan Province in southwestern China. The thesis argues that traditional irrigation practices vital to paddy-rice production in the village have been stressed by local weather events. It also argues that local villagers have not responded effectively to such changes, and that failure to adjust has contributed to social stress observed at the site. During the earlier years of the study period (1945 to 2012), improvements were made in local irrigation, which seem to have helped farmers continue with traditional subsistence wet-rice farming in a fragile mountain environment. However, in later years of the period village social order showed two significant signs of collapse: first, because of emigration, fewer people were left to farm higher mountain levels so farm land was being abandoned; second, social crowding in lower level riverside farming areas, partly the result of highland emigration, began reducing the amount of land being farmed there. While reducing intensive cropping of highland farming areas can result in spontaneous recovery of natural resources such as soil and water, crowding in lower areas can contribute to deterioration of natural resources in the lower village farmland. Crowding can, in addition, have a bearing on community health problems. The thesis results are of value to researchers concerned with the adaptive behavior of local farming communities trying to maintain their traditional irrigation-dependent way of life in a fragile mountain environment while experiencing the effects of changeable weather. Thesis results are of additional value to those who study the impact on society of earth-warming, especially if variable local weather in the Dabashan is shown to be related to global climate change. Title: Beyond Sustainable Bounds: Changing Weather, Emigration, and Irrigation in a Farming Village of Sichuan, China, 1945-2012 Author: Parker, Joseph Lynn Year: 2013 This thesis presents the results of research in a small village located in the mountains of Sichuan Province in southwestern China. The thesis argues that traditional irrigation practices vital to paddy-rice production in the village have been stressed by local weather events. It also argues that local villagers have not responded effectively to such changes, and that failure to adjust has contributed to social stress observed at the site. During the earlier years of the study period (1945 to 2012), improvements were made in local irrigation, which seem to have helped farmers continue with traditional subsistence wet-rice farming in a fragile mountain environment. However, in later years of the period village social order showed two significant signs of collapse: first, because of emigration, fewer people were left to farm higher mountain levels so farm land was being abandoned; second, social crowding in lower level riverside farming areas, partly the result of highland emigration, began reducing the amount of land being farmed there. While reducing intensive cropping of highland farming areas can result in spontaneous recovery of natural resources such as soil and water, crowding in lower areas can contribute to deterioration of natural resources in the lower village farmland. Crowding can, in addition, have a bearing on community health problems. The thesis results are of value to researchers concerned with the adaptive behavior of local farming communities trying to maintain their traditional irrigation-dependent way of life in a fragile mountain environment while experiencing the effects of changeable weather. Thesis results are of additional value to those who study the impact on society of earth-warming, especially if variable local weather in the Dabashan is shown to be related to global climate change. Close

• 10. [Article] Safety in Maize: Subsistence Agriculture in a Zapotec Migrant Town

  Subsistence maize production has long been a dominant economic activity of households in Santiago Apóstol, a Zapotec community in the Central Valley of Oaxaca, Mexico. A baseline study from 1973 documents ...

  Citation × Citation Citation Abstract Copy Title: Safety in Maize: Subsistence Agriculture in a Zapotec Migrant Town Author: Gladstone, Fiona Joy Year: 2014 Subsistence maize production has long been a dominant economic activity of households in Santiago Apóstol, a Zapotec community in the Central Valley of Oaxaca, Mexico. A baseline study from 1973 documents a regionally pervasive form of household level agriculture whereby cultivators prioritize land for subsistence maize above commercial crops. Since then, much has transformed the face of rural Mexico, including migration to the United States. Migration accelerated beginning in the 1970s as a response to government disinvestment in maize, but it may also be a new force of cultural and economic change impacting agriculture. The question arises, has migration modified longstanding subsistence agricultural practices centered on local varieties of rainfed maize? If not, what might explain the continuities and changes in agricultural practice observed? Ethnographic land use and maize consumption surveys among 19 migrant headed households conducted in Santiago Apóstol in the summer and winter of 2012 indicate that mean production of maize remains equivalent to that documented in the late 1960s, suggesting that migration has not engendered a generalized shift to commercial crops. Potential explanations for the persistent use of rainfed, local maize among migrant headed households are drawn from a mixed methods methodology involving triangulated analyses of household economic data, land tenure arrangements, perceptions of environmental change, participant observation, and archival research. Triangulated analyses allow speculation on linked human environmental changes in the landscape that may have reinforced use of a traditional, rainfed grain crop. Title: Safety in Maize: Subsistence Agriculture in a Zapotec Migrant Town Author: Gladstone, Fiona Joy Year: 2014 Subsistence maize production has long been a dominant economic activity of households in Santiago Apóstol, a Zapotec community in the Central Valley of Oaxaca, Mexico. A baseline study from 1973 documents a regionally pervasive form of household level agriculture whereby cultivators prioritize land for subsistence maize above commercial crops. Since then, much has transformed the face of rural Mexico, including migration to the United States. Migration accelerated beginning in the 1970s as a response to government disinvestment in maize, but it may also be a new force of cultural and economic change impacting agriculture. The question arises, has migration modified longstanding subsistence agricultural practices centered on local varieties of rainfed maize? If not, what might explain the continuities and changes in agricultural practice observed? Ethnographic land use and maize consumption surveys among 19 migrant headed households conducted in Santiago Apóstol in the summer and winter of 2012 indicate that mean production of maize remains equivalent to that documented in the late 1960s, suggesting that migration has not engendered a generalized shift to commercial crops. Potential explanations for the persistent use of rainfed, local maize among migrant headed households are drawn from a mixed methods methodology involving triangulated analyses of household economic data, land tenure arrangements, perceptions of environmental change, participant observation, and archival research. Triangulated analyses allow speculation on linked human environmental changes in the landscape that may have reinforced use of a traditional, rainfed grain crop. Close