Open Access. Powered by Scholars. Published by Universities.®

Life Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 25 of 25

Full-Text Articles in Life Sciences

The Other Side Of Silence: Rachel Carson’S Views Of Animals, Marc Bekoff, Jan Nystrom Sep 2016

The Other Side Of Silence: Rachel Carson’S Views Of Animals, Marc Bekoff, Jan Nystrom

Marc Bekoff, PhD

The publication of Rachel Carson’s Silent Spring in 1962 is widely regarded as one of the major events that launched the modern environmental movement. Silent Spring is a compelling blend of stories, natural history, human values, and biological facts. In this essay we consider Carson’s attitude toward animals in Silent Spring and in other texts. Despite the facts that she was raised to love Nature and animals, little direct attention has been given to Carson’s views about our moral responsibilities to, and the moral standing of animals. Carson favored responsible stewardship, was more of an animal welfarist and environmentalist/conservation biologist …


Compassion As A Practical And Evolved Ethic For Conservation, David Ramp, Marc Bekoff Sep 2016

Compassion As A Practical And Evolved Ethic For Conservation, David Ramp, Marc Bekoff

Marc Bekoff, PhD

The ethical position underpinning decisionmaking is an important concern for conservation biologists when setting priorities for interventions. The recent debate on how best to protect nature has centered on contrasting intrinsic and aesthetic values against utilitarian and economic values, driven by an inevitable global rise in conservation conflicts. These discussions have primarily been targeted at species and ecosystems for success, without explicitly expressing concern for the intrinsic value and welfare of individual animals. In part, this is because animal welfare has historically been thought of as an impediment to conservation. However, practical implementations of conservation that provide good welfare outcomes …


Prototype For Monitoring And Forecasting Fall Foliage Coloration In Real Time From Satellite Data, Xiaoyang Zhang, Mitchell D. Goldberg, Yunyue Yu Sep 2016

Prototype For Monitoring And Forecasting Fall Foliage Coloration In Real Time From Satellite Data, Xiaoyang Zhang, Mitchell D. Goldberg, Yunyue Yu

Xiaoyang Zhang

While determining vegetation phenology from the time series of historical satellite data has been widely investigated throughout the last decade, little effort has been devoted to real-time monitoring and short-term forecasting. The latter is more important for numerical weather modeling, ecosystem forecasting, forest and crop management, and health risk warning. In this study we developed a prototype approach for the real-time monitoring and short-term forecasting of fall foliage status (including low coloration, moderate coloration, near-peak coloration, peak coloration, and post-peak coloration) using temporal satellite observations. The algorithm combined the climatology of vegetation phenology and temporally available satellite observations to establish …


Estimation Of Crop Gross Primary Production (Gpp): Ii. Do Scaled Modis Vegetation Indices Improve Performance?, Qingyuan Zhang, Yen-Ben Cheng, Alexei I. Lyapustin, Yujie Wang, Xiaoyang Zhang, Andrew Suyker, Shashi Verma, Yanmin Shuai, Elizabeth M. Middleton Sep 2016

Estimation Of Crop Gross Primary Production (Gpp): Ii. Do Scaled Modis Vegetation Indices Improve Performance?, Qingyuan Zhang, Yen-Ben Cheng, Alexei I. Lyapustin, Yujie Wang, Xiaoyang Zhang, Andrew Suyker, Shashi Verma, Yanmin Shuai, Elizabeth M. Middleton

Xiaoyang Zhang

Satellite remote sensing estimates of gross primary production (GPP) have routinely been made using spectral vegetation indices (VIs) over the past two decades. The Normalized Difference Vegetation Index (NDVI), the Enhanced Vegetation Index (EVI), the green band Wide Dynamic Range Vegetation Index (WDRVIgreen), and the green band Chlorophyll Index (CIgreen) have been employed to estimate GPP under the assumption that GPP is proportional to the product of VI and photosynthetically active radiation (PAR) (where VI is one of four VIs: NDVI, EVI, WDRVIgreen, or CIgreen). However, the empirical regressions between VI*PAR and …


Ignoring Nature: Why We Do It, The Dire Consequences, And The Need For A Paradigm Shift To Save Animals, Habitats, And Ourselves, Marc Bekoff, Sarah Bexell Sep 2016

Ignoring Nature: Why We Do It, The Dire Consequences, And The Need For A Paradigm Shift To Save Animals, Habitats, And Ourselves, Marc Bekoff, Sarah Bexell

Marc Bekoff, PhD

The article discusses the importance of biodiversity and on how people protect animals and habitats. It describes the conservation psychology and conservation social work. It suggests that there will be fewer people who will actually be able to make a positive difference in the relationships with animals and ecosystems.


Mapping Temperate Vegetation Climate Adaptation Variability Using Normalized Land Surface Phenology, Liang Liang, Mark D. Schwartz, Xiaoyang Zhang Sep 2016

Mapping Temperate Vegetation Climate Adaptation Variability Using Normalized Land Surface Phenology, Liang Liang, Mark D. Schwartz, Xiaoyang Zhang

Xiaoyang Zhang

Climate influences geographic differences of vegetation phenology through both contemporary and historical variability. The latter effect is embodied in vegetation heterogeneity underlain by spatially varied genotype and species compositions tied to climatic adaptation. Such long-term climatic effects are difficult to map and therefore often neglected in evaluating spatially explicit phenological responses to climate change. In this study we demonstrate a way to indirectly infer the portion of land surface phenology variation that is potentially contributed by underlying genotypic differences across space. The method undertaken normalized remotely sensed vegetation start-of-season (or greenup onset) with a cloned plants-based phenological model. As the …


Probing The Past 30-Year Phenology Trend Of Us Deciduous Forests, X. Yue, N. Unger, Xiaoyang Zhang, C.S. Vogel Sep 2016

Probing The Past 30-Year Phenology Trend Of Us Deciduous Forests, X. Yue, N. Unger, Xiaoyang Zhang, C.S. Vogel

Xiaoyang Zhang

Phenology is experiencing dramatic changes over deciduous forests in the USA. Estimates of trends in phenology on the continental scale are uncertain, however, with studies failing to agree on both the magnitude and spatial distribution of trends in spring and autumn. This is due to the sparsity of in situ records, uncertainties associated with remote sensing data, and the regional focus of many studies. It has been suggested that reported trends are a result of recent temperature changes, though multiple processes are thought to be involved and the nature of the temperature forcing remains unknown. To date, no study has …


In-Season N Fertilization Strategies Using Active Sensors, Daniel Barker, John Sawyer Jul 2016

In-Season N Fertilization Strategies Using Active Sensors, Daniel Barker, John Sawyer

John E. Sawyer

The objectives of this project were to measure corn yield response to applied nitrogen (N) fertilizer based on active canopy sensing during the mid-vegetative corn growth stage (V10) and compare yield and N use efficiency between pre-plant N (PP-N), pre-plant + sensor N (PP+S-N), split N strategy (SNS), and rescue N strategy (RNS).


In-Season N Fertilization Strategies Using Active Sensors, Daniel Barker, John Sawyer Jul 2016

In-Season N Fertilization Strategies Using Active Sensors, Daniel Barker, John Sawyer

John E. Sawyer

The objectives of this project were to measure corn yield response to applied nitrogen (N) fertilizer based on active canopy sensing during the mid-vegetative corn growth stage (V10) and compare yield and N use efficiency between pre-plant N (PP-N), pre-plant + sensor N (PP+S-N), split N strategy (SNS), and rescue N strategy (RNS).


In-Season N Fertilization Strategies Using Active Sensors, Daniel Barker, John Sawyer Jul 2016

In-Season N Fertilization Strategies Using Active Sensors, Daniel Barker, John Sawyer

John E. Sawyer

The objectives of this project were to measure corn yield response to applied nitrogen (N) fertilizer based on active canopy sensing during the mid-vegetative corn growth stage (V10) and compare yield and N use efficiency between pre-plant N (PP-N), pre-plant + sensor N (PP+S-N), split N strategy (SNS), and rescue N strategy (RNS).


In-Season N Fertilization Strategies Using Active Sensors, Daniel Barker, John Sawyer Jul 2016

In-Season N Fertilization Strategies Using Active Sensors, Daniel Barker, John Sawyer

John E. Sawyer

The objectives of this project were to measure corn yield response to applied nitrogen (N) fertilizer based on active canopy sensing during the mid-vegetative corn growth stage (V10) and compare yield and N use efficiency between pre-plant N (PP-N), pre-plant + sensor N (PP+S-N), split N strategy (SNS), and rescue N strategy (RNS).


In-Season N Fertilization Strategies Using Active Sensors, Daniel Barker, John Sawyer Jul 2016

In-Season N Fertilization Strategies Using Active Sensors, Daniel Barker, John Sawyer

John E. Sawyer

The objectives of this project were to measure corn yield response to applied nitrogen (N) fertilizer based on active canopy sensing during the mid-vegetative corn growth stage (V10) and compare yield and N use efficiency between pre-plant N (PP-N), pre-plant + sensor N (PP+S-N), split N strategy (SNS), and rescue N strategy (RNS).


In-Season N Fertilization Strategies Using Active Sensors, Daniel Barker, John Sawyer Jul 2016

In-Season N Fertilization Strategies Using Active Sensors, Daniel Barker, John Sawyer

John E. Sawyer

The objectives of this project were to measure corn yield response to applied nitrogen (N) fertilizer based on active canopy sensing during the mid-vegetative corn growth stage (V10) and compare yield and N use efficiency between pre-plant N (PP-N), pre-plant + sensor N (PP+S-N), split N strategy (SNS), and rescue N strategy (RNS).


Impacts Of Cover Crops On Phosphorus And Nitrogen Loss With Surface Runoff, Antonio Mallarino, Richard Cruse, Dan Jaynes, John Sawyer, Pablo Barbieri Jul 2016

Impacts Of Cover Crops On Phosphorus And Nitrogen Loss With Surface Runoff, Antonio Mallarino, Richard Cruse, Dan Jaynes, John Sawyer, Pablo Barbieri

John E. Sawyer

Iowa research has demonstrated that cover crops can improve soil productivity and water quality by increasing soil organic matter and reducing nitrate nitrogen (N) leaching. Other research has investigated and is investigating the agronomic and economic viability of using cereal rye cover crops in continuous corn or corn-soybean rotations. However, no Iowa research has evaluated under natural rainfall the impact of cover crops on phosphorus (P) and N loss with surface runoff interacting with other management practices. The need for this type of research was indicated in the Iowa Nutrient Reduction Strategy documents. This effort assessed what would be needed …


Impact Of 4r Management On Crop Production And Nitrate-Nitrogen Loss In Tile Drainage, Matthew Helmers, John Sawyer, Josh Sievers Jul 2016

Impact Of 4r Management On Crop Production And Nitrate-Nitrogen Loss In Tile Drainage, Matthew Helmers, John Sawyer, Josh Sievers

John E. Sawyer

Corn Belt corn and soybean producers are increasingly challenged to maximize crop production while addressing the contributions farm practices make to Gulf hypoxia. Based on the need for nitrate-N reductions to meet water quality goals, new management practices are needed to reduce nitrate-N losses at minimal cost and maximum economic benefits. This three-year field research and demonstration project is evaluating various promising N management methods and technologies by documenting the nitrate-N export and crop yield from various systems.


Implications Of Changes (Structural And Market) On Farm Management And Marketing Research, George R. Allen, Lester S. Kellogg, G. Edward Schuh, Vernon W. Pherson, Reynold P. Dahl, Rex F. Daly, Dale E. Hathaway, Neil E. Harl, Earl O. Heady, A. Gordon Ball, Glenn L. Johnson, Dale O. Anderson, Lowell D. Hill, John C. Redman, Robert W. Rudd, B. F. Jones, A. Allen Schmid, Karl A. Fox, George D. Irwin, R. L. Kohls, John E. Lee Jr., Thomas T. Stout Jul 2016

Implications Of Changes (Structural And Market) On Farm Management And Marketing Research, George R. Allen, Lester S. Kellogg, G. Edward Schuh, Vernon W. Pherson, Reynold P. Dahl, Rex F. Daly, Dale E. Hathaway, Neil E. Harl, Earl O. Heady, A. Gordon Ball, Glenn L. Johnson, Dale O. Anderson, Lowell D. Hill, John C. Redman, Robert W. Rudd, B. F. Jones, A. Allen Schmid, Karl A. Fox, George D. Irwin, R. L. Kohls, John E. Lee Jr., Thomas T. Stout

Neil E. Harl

This conference was really an outgrowth of an earlier conference on Structural Changes in Commercial Agriculture (CAED Report 24) held in Chicago, April 12-14, 1965. While the earlier conference emphasized structural changes in the agricultural industry and their implications for education and extension, the 1967 conference focused on research.


Does A Rising Biofuels Tide Raise All Boats? A Study Of Cash Rent Determinants For Iowa Farmland Under Hay And Pasture, Xiaodong Du, David A. Hennessy, William M. Edwards Jul 2016

Does A Rising Biofuels Tide Raise All Boats? A Study Of Cash Rent Determinants For Iowa Farmland Under Hay And Pasture, Xiaodong Du, David A. Hennessy, William M. Edwards

William Edwards

Iowa's farmland consists of over 16% hay crops and pastureland, a significant portion of which is under cash rental contracts. This study investigates the comparative relationships between cash rental rates for cropped land and non-cropped land, where the latter includes hay and pastureland. We find that higher crop prices resulting from biofuel demand induces land use conversion from non-cropped land to crop production and thus bids up non-cropped land rents. Compared with changes in cropped land cash rents, non-cropped farmland rents could increase by a higher percentage. Non-cropped land cash rental rates are largely determined by crop and feeder cattle …


Does A Rising Biofuels Tide Raise All Boats? A Study Of Cash Rent Determinants For Iowa Farmland Under Hay And Pasture, Xiaodong Du, David A. Hennessy, William M. Edwards Jul 2016

Does A Rising Biofuels Tide Raise All Boats? A Study Of Cash Rent Determinants For Iowa Farmland Under Hay And Pasture, Xiaodong Du, David A. Hennessy, William M. Edwards

William Edwards

Iowa's farmland consists of over 16% hay crops and pastureland, a significant portion of which is under cash rental contracts. This study investigates the comparative relationships between cash rental rates for cropped land and non-cropped land, where the latter includes hay and pastureland. We find that higher crop prices resulting from biofuel demand induces land use conversion from non-cropped land to crop production and thus bids up non-cropped land rents. Compared with changes in cropped land cash rents, non-cropped farmland rents could increase by a higher percentage. Non-cropped land cash rental rates are largely determined by crop and feeder cattle …


Does A Rising Biofuels Tide Raise All Boats? A Study Of Cash Rent Determinants For Iowa Farmland Under Hay And Pasture, Xiaodong Du, David A. Hennessy, William M. Edwards Jul 2016

Does A Rising Biofuels Tide Raise All Boats? A Study Of Cash Rent Determinants For Iowa Farmland Under Hay And Pasture, Xiaodong Du, David A. Hennessy, William M. Edwards

William Edwards

Iowa's farmland consists of over 16% hay crops and pastureland, a significant portion of which is under cash rental contracts. This study investigates the comparative relationships between cash rental rates for cropped land and non-cropped land, where the latter includes hay and pastureland. We find that higher crop prices resulting from biofuel demand induces land use conversion from non-cropped land to crop production and thus bids up non-cropped land rents. Compared with changes in cropped land cash rents, non-cropped farmland rents could increase by a higher percentage. Non-cropped land cash rental rates are largely determined by crop and feeder cattle …


Does A Rising Biofuels Tide Raise All Boats? A Study Of Cash Rent Determinants For Iowa Farmland Under Hay And Pasture, Xiaodong Du, David A. Hennessy, William M. Edwards Jul 2016

Does A Rising Biofuels Tide Raise All Boats? A Study Of Cash Rent Determinants For Iowa Farmland Under Hay And Pasture, Xiaodong Du, David A. Hennessy, William M. Edwards

William Edwards

Iowa's farmland consists of over 16% hay crops and pastureland, a significant portion of which is under cash rental contracts. This study investigates the comparative relationships between cash rental rates for cropped land and non-cropped land, where the latter includes hay and pastureland. We find that higher crop prices resulting from biofuel demand induces land use conversion from non-cropped land to crop production and thus bids up non-cropped land rents. Compared with changes in cropped land cash rents, non-cropped farmland rents could increase by a higher percentage. Non-cropped land cash rental rates are largely determined by crop and feeder cattle …


Density, Abundance, And Habitat Associations Of The Inland Swamp Sparrow (Melospiza Georgiana Georgiana) In Iowa, Tyler Harms, Stephen Dinsmore Mar 2016

Density, Abundance, And Habitat Associations Of The Inland Swamp Sparrow (Melospiza Georgiana Georgiana) In Iowa, Tyler Harms, Stephen Dinsmore

Tyler Harms

Wetlands continue to decline throughout North America and the Prairie Pothole Region, thus emphasizing the importance of understanding population trends and habitat associations of wetland species to ensure effective conservation and habitat management of those species. We estimated density and abundance and evaluated habitat associations of the Inland Swamp Sparrow (Melospiza georgiana georgiana) in Iowa. We conducted standardized distance sampling surveys for Swamp Sparrows and measured habitat characteristics at 307 wetlands in two regions of Iowa in 2009 and 2010. We used Program Distance to model detection probability and estimate region-specific breeding densities of Swamp Sparrows at Iowa …


Influence Of Season And Time Of Day On Marsh Bird Detections, Tyler Harms, Stephen Dinsmore Mar 2016

Influence Of Season And Time Of Day On Marsh Bird Detections, Tyler Harms, Stephen Dinsmore

Tyler Harms

Call-broadcast surveys are frequently used to elicit responses of secretive marsh birds and produce greater detection rates than passive surveys. However, little is known about how detection rates of birds from these surveys differ by season and time of day. We conducted call-broadcast surveys for eight focal species at 56 wetlands throughout Iowa from 15 May–13 June 2010 (early season) and from 15 June–10 July 2010 (late season). Our focal species were Pied-billed Grebe (Podilymbus podiceps), American Bittern (Botaurus lentiginosus), Least Bittern (Ixobrychus exilis), King Rail (Rallus elegans), Virginia Rail (Rallus …


Density And Abundance Of Secretive Marsh Birds In Iowa, Tyler Harms, Stephen Dinsmore Mar 2016

Density And Abundance Of Secretive Marsh Birds In Iowa, Tyler Harms, Stephen Dinsmore

Tyler Harms

A decrease in wetland habitats throughout North America has caused a decline in populations of marsh birds. The objective of this study was to estimate population densities and abundances of secretive marsh birds in Iowa. Call-broadcast surveys were conducted in conjunction with distance sampling for eight species of marsh birds at wetlands in three regions of Iowa during 2009 and 2010. Regions were defined by observed microhabitat characteristics which also corresponded to physiographic regions. Region-specific density estimates were obtained using Program Distance for four species of marsh birds for which sufficient detections existed (Pied-billed Grebe [Podilymbus podiceps], Least …


Influence Of Season And Time Of Day On Marsh Bird Detections, Tyler Harms, Stephen J. Dinsmore Mar 2016

Influence Of Season And Time Of Day On Marsh Bird Detections, Tyler Harms, Stephen J. Dinsmore

Tyler Harms

Call-broadcast surveys are frequently used to elicit responses of secretive marsh birds and produce greater detection rates than passive surveys. However, little is known about how detection rates of birds from these surveys differ by season and time of day. We conducted call-broadcast surveys for eight focal species at 56 wetlands throughout Iowa from 15 May–13 June 2010 (early season) and from 15 June–10 July 2010 (late season). Our focal species were Pied-billed Grebe (Podilymbus podiceps), American Bittern (Botaurus lentiginosus), Least Bittern (Ixobrychus exilis), King Rail (Rallus elegans), Virginia Rail (Rallus …


Human–Wildlife Conflict And Coexistence, Philip J. Nyhus Dec 2015

Human–Wildlife Conflict And Coexistence, Philip J. Nyhus

Philip J. Nyhus

Human interactions with wildlife are a defining experience of human existence. These interactions can be positive or negative. People compete with wildlife for food and resources, and have eradicated dangerous species; co-opted and domesticated valuable species; and applied a wide range of social, behavioral, and technical approaches to reduce negative interactions with wildlife. This conflict has led to the extinction and reduction of numerous species and uncountable human deaths and economic losses. Recent advances in our understanding of conflict have led to a growing number of positive conservation and coexistence outcomes. I summarize and synthesize factors that contribute to conflict, …