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

Life Sciences Commons

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

Articles 1 - 22 of 22

Full-Text Articles in Life Sciences

Reconstructing Vegetation Past: Pre-Euro-American Vegetation For The Midwest Driftless Area, Usa, Monika E. Shea, Lisa A. Schulte, Brian J. Palik Dec 2014

Reconstructing Vegetation Past: Pre-Euro-American Vegetation For The Midwest Driftless Area, Usa, Monika E. Shea, Lisa A. Schulte, Brian J. Palik

Natural Resource Ecology and Management Publications

Historical reference conditions provide important context for creating ecological restoration and management plans. The U.S. 19th Century Public Land Survey (PLS) records provide extensive ecological information for constructing such reference conditions. We used PLS records to reconstruct pre-Euro-American tree species cover class and vegetation structure types for the Midwest Driftless Area, a 55,000 km2 region currently experiencing multiple conservation threats. We related cover classes to soil texture, topographic roughness, and distance from waterway. Our analyses revealed that the landscape of the Driftless Area was mostly composed of savanna, with two large patches of closed forest and smaller, scattered ...


Satellite-Based Management Tool For Oak Savanna Ecosystem Restoration, Peter T. Wolter, Elizabeth A. Berkley, Scott D. Peckham, Aditya Singh Dec 2014

Satellite-Based Management Tool For Oak Savanna Ecosystem Restoration, Peter T. Wolter, Elizabeth A. Berkley, Scott D. Peckham, Aditya Singh

Natural Resource Ecology and Management Publications

The structure and function of oak Quercus spp. savanna ecosystems in the North American Midwest were originally maintained by an active disturbance regime (often fire). Subsequent reductions in the frequency of disturbance after European settlement have facilitated rapid, regional conversion of these ecosystems to more closed-canopy forest. Hence, regional-scale management strategies are now needed to restore critical spatial gradients of light, temperature, soil moisture, and soil organic matter for recovery and sustenance of the unique mosaic of understory grass and forb species assemblages that define oak savannas. Tree species composition, distribution, mortality, basal area, and canopy cover are important forest ...


Book Review Of Conservation By Proxy: Indicator, Umbrella, Keystone, Flagship, And Other Surrogate Species, Tyler J. Grant, Peter G. Eyheralde, Melissa S. C. Telemeco, Amy L. Moorhouse, Rebecca A. Reeves, Karin Grimlund, Amy Podaril, Sarah E. Emeterio, Robert W. Klaver Dec 2014

Book Review Of Conservation By Proxy: Indicator, Umbrella, Keystone, Flagship, And Other Surrogate Species, Tyler J. Grant, Peter G. Eyheralde, Melissa S. C. Telemeco, Amy L. Moorhouse, Rebecca A. Reeves, Karin Grimlund, Amy Podaril, Sarah E. Emeterio, Robert W. Klaver

Natural Resource Ecology and Management Publications

In the tallgrass prairies of the United States, the regal fritillary (Speyeria idalia) often is considered a reliable indicator of high quality remnant habitat. Purple milkweed (Asclepias purpurascens) is considered an indicator of high quality oak savanna habitat at the edge of prairie. Indicator and other surrogate species often are regarded as inescapable necessities in conservation, because limited budgets and the myriad pieces of an ecosystem render comprehensive monitoring impossible. Regardless of whether or not surrogate species are necessary, do they really work?


Reproductive Success Of The American Oystercatcher (Haematopus Palliatus) In Texas, Lianne M. Koczur, Alexandra E. Munters, Susan A. Heath, Bart M. Ballard, M. Clay Green, Stephen J. Dinsmore, Fidel Hernández Dec 2014

Reproductive Success Of The American Oystercatcher (Haematopus Palliatus) In Texas, Lianne M. Koczur, Alexandra E. Munters, Susan A. Heath, Bart M. Ballard, M. Clay Green, Stephen J. Dinsmore, Fidel Hernández

Natural Resource Ecology and Management Publications

The American Oystercatcher (Haematopus palliatus) is listed as a Species of High Concern in the United States Shorebird Conservation Plan due to a small population size and threats during its annual cycle. Previous studies of the American Oystercatcher have focused on Atlantic Coast populations; however, little is known about the reproductive success of the western Gulf Coast population. The objective of this study was to determine nest and brood survival of American Oystercatchers in Texas. A total of 337 nests and 121 broods were monitored on the Texas Gulf Coast during 2011–2013. The top model for nest survival in ...


Predator Exclosures, Predator Removal, And Habitat Improvement Increase Nest Success Of Snowy Plovers In Oregon, Usa, Stephen J. Dinsmore, David J. Lauten, Kathleen A. Castelein, Eleanor P. Gaines, Mark A. Stern Nov 2014

Predator Exclosures, Predator Removal, And Habitat Improvement Increase Nest Success Of Snowy Plovers In Oregon, Usa, Stephen J. Dinsmore, David J. Lauten, Kathleen A. Castelein, Eleanor P. Gaines, Mark A. Stern

Natural Resource Ecology and Management Publications

Management to increase reproductive success is commonly used to aid recovery of threatened and endangered species. The Western Snowy Plover (Charadrius nivosus nivosus) breeds from coastal Washington, USA, to Baja California, Mexico, and in disjunct interior sites. The Pacific coast population is federally listed as Threatened; habitat loss and nest loss to a suite of terrestrial and avian predators are thought to be primary factors limiting population growth in this species. In coastal Oregon, USA, a consortium of state and federal management agencies deployed nest exclosures on active Snowy Plover nests, initiated a lethal predator management program, and conducted local-scale ...


Anthropogenic Disturbance And Environmental Associations With Fish Assemblage Structure In Two Nonwadeable Rivers, T. P. Parks, M. C. Quist, Clay L. Pierce Oct 2014

Anthropogenic Disturbance And Environmental Associations With Fish Assemblage Structure In Two Nonwadeable Rivers, T. P. Parks, M. C. Quist, Clay L. Pierce

Natural Resource Ecology and Management Publications

Nonwadeable rivers are unique ecosystems that support high levels of aquatic biodiversity, yet they have been greatly altered by human activities. Although riverine fish assemblages have been studied in the past, we still have an incomplete understanding of how fish assemblages respond to both natural and anthropogenic influences in large rivers. The purpose of this study was to evaluate associations between fish assemblage structure and reach-scale habitat, dam, and watershed land use characteristics. In the summers of 2011 and 2012, comprehensive fish and environmental data were collected from 33 reaches in the Iowa and Cedar rivers of eastern-central Iowa. Canonical ...


Re-Evaluating Neonatal-Age Models For Ungulates: Does Model Choice Affect Survival Estimates?, Troy W. Grovenburg, Kevin L. Monteith, Christopher N. Jacques, Robert W. Klaver, Christopher S. Deperno, Todd J. Brinkman, Kyle B. Monteith, Sophie L. Gilbert, Joshua B. Smith, Vernon C. Bleich, Christopher C. Swanson, Jonathan A. Jenks Sep 2014

Re-Evaluating Neonatal-Age Models For Ungulates: Does Model Choice Affect Survival Estimates?, Troy W. Grovenburg, Kevin L. Monteith, Christopher N. Jacques, Robert W. Klaver, Christopher S. Deperno, Todd J. Brinkman, Kyle B. Monteith, Sophie L. Gilbert, Joshua B. Smith, Vernon C. Bleich, Christopher C. Swanson, Jonathan A. Jenks

Natural Resource Ecology and Management Publications

New-hoof growth is regarded as the most reliable metric for predicting age of newborn ungulates, but variation in estimated age among hoof-growth equations that have been developed may affect estimates of survival in staggered-entry models. We used known-age newborns to evaluate variation in age estimates among existing hoof-growth equations and to determine the consequences of that variation on survival estimates. During 2001–2009, we captured and radiocollared 174 newborn (≤24-hrs old) ungulates: 76 white-tailed deer (Odocoileus virginianus) in Minnesota and South Dakota, 61 mule deer (O. hemionus) in California, and 37 pronghorn (Antilocapra americana) in South Dakota. Estimated age of ...


Unexpected Effects Of Chitin, Cellulose, And Lignin Addition On Soil Dynamics In A Wet Tropical Forest, Ann E. Russell Aug 2014

Unexpected Effects Of Chitin, Cellulose, And Lignin Addition On Soil Dynamics In A Wet Tropical Forest, Ann E. Russell

Natural Resource Ecology and Management Publications

Decades of studies on the role of decomposition in carbon (C) and nitrogen (N) cycling have focused on organic matter (OM) of plant origin. Despite potentially large inputs of belowground OM from fungal cell walls and invertebrate exoskeletons, studies of the decomposability of their major constituent, chitin, are scarce. To explore effects on soil C dynamics of chitin, in comparison with two plant-derived chemicals, cellulose and lignin, I conducted a field-based chemical-addition experiment. The design contained three chemical treatments plus a control, with four replicates in each of two species of tropical trees grown in plantations. The chemicals were added ...


Effects Of Set-Aside Conservation Practices On Bird Community Structure Within An Intensive Agricultural Landscape, Ross Robert Conover, Stephen J. Dinsmore, L. Wes Burger Jr. Jul 2014

Effects Of Set-Aside Conservation Practices On Bird Community Structure Within An Intensive Agricultural Landscape, Ross Robert Conover, Stephen J. Dinsmore, L. Wes Burger Jr.

Natural Resource Ecology and Management Publications

Creating and restoring patches of noncrop early-succession vegetation within agricultural landscapes may mitigate grassland bird population declines caused by agricultural land use and intensification. Achieving this goal requires an ability to balance avian benefits with agronomics, which may be facilitated by understanding how bird communities respond to various conservation practices. We evaluated bird richness, abundance, Shannon diversity, and Total Avian Conservation Value in 20 replicates of four Conservation Reserve Program practices in an intensive rowcrop agricultural landscape in the Mississippi Alluvial Valley from May–Jul., 2005–2007. Conservation practices included: (1) large blocks of structurally-diverse early-succession vegetation (6–8 y ...


Small Changes, Big Impacts: Prairie Conservation Strips, Mary A. Harris, Geetha Iyer Jul 2014

Small Changes, Big Impacts: Prairie Conservation Strips, Mary A. Harris, Geetha Iyer

Natural Resource Ecology and Management Publications

Agriculture in Iowa owes its immense productivity to an extreme trade-off. Once, perennial prairie covered 85 percent of the state, and its deep root network built and held together a fertile topsoil layer many feet deep. Now, more than 85 percent is in agricultural production, with the majority in row crops.


Native Tree Species Regulate Nitrous Oxide Fluxes In Tropical Plantations, Samantha R. Weintraub, Ann E. Russell, Alan R. Townsend Jun 2014

Native Tree Species Regulate Nitrous Oxide Fluxes In Tropical Plantations, Samantha R. Weintraub, Ann E. Russell, Alan R. Townsend

Natural Resource Ecology and Management Publications

Secondary and managed plantation forests comprise a rapidly increasing portion of the humid tropical forest biome, a region that, in turn, is a major source of nitrous oxide (N2O) emissions to the atmosphere. Previous work has demonstrated reduced N2O emissions in regenerating secondary stands compared to mature forests, yet the importance of species composition in regulating N2O production in young forests remains unclear. We measured N2O fluxes beneath four native tree species planted in replicated, 21-yr-old monodominant stands in the Caribbean lowlands of Costa Rica in comparison with nearby mature forest and ...


Biodiversity, Photosynthetic Mode, And Ecosystem Services Differ Between Native And Novel Ecosystems, Leanne M. Martin, H. Wayne Polley, Pedram P. Daneshgar, Mary A. Harris, Brian J. Wilsey Jun 2014

Biodiversity, Photosynthetic Mode, And Ecosystem Services Differ Between Native And Novel Ecosystems, Leanne M. Martin, H. Wayne Polley, Pedram P. Daneshgar, Mary A. Harris, Brian J. Wilsey

Natural Resource Ecology and Management Publications

Human activities have caused non-native plant species with novel ecological interactions to persist on landscapes, and it remains controversial whether these species alter multiple aspects of communities and ecosystems. We tested whether native and exotic grasslands differ in species diversity, ecosystem services, and an important aspect of functional diversity (C3:C4 proportions) by sampling 42 sites along a latitudinal gradient and conducting a controlled experiment. Exotic-dominated grasslands had drastically lower plant diversity and slightly higher tissue N concentrations and forage quality compared to native-dominated sites. Exotic sites were strongly dominated by C4 species at southern and C3 species at northern ...


Prairie Conservation Strips On My Land: Frequently Asked Questions, Mary A. Harris, Jeri Neal May 2014

Prairie Conservation Strips On My Land: Frequently Asked Questions, Mary A. Harris, Jeri Neal

Natural Resource Ecology and Management Publications

VISIT STRIPS in Jasper County: Neal Smith National Wildlife Refuge 9981 Pacific Street, Prairie City, Iowa (515) 994-3400, NealSmith@fws.gov. FIND more resources on the web: The STRIPS research team website includes information on partners and participants, as well as upcoming field days and demonstration site locations. Find more at: www.prairiestrips.org. The Leopold Center for Sustainable Agriculture has compiled various multimedia resources, including: A Landowner’s Guide to Prairie Conservation Strips, The Cost of Prairie Conservation Strips and Small Changes, Big Impacts: Prairie Conservation Strips. Find more at: www.leopold.iastate.edu/strips-research-team.


Fish Assemblage Relationships With Physical Characteristics And Presence Of Dams In Three Eastern Iowa Rivers, Clay L. Pierce, N. L. Ahrens, A. K. Loan-Wilsey, G. A. Simmons, G. T. Gelwicks May 2014

Fish Assemblage Relationships With Physical Characteristics And Presence Of Dams In Three Eastern Iowa Rivers, Clay L. Pierce, N. L. Ahrens, A. K. Loan-Wilsey, G. A. Simmons, G. T. Gelwicks

Natural Resource Ecology and Management Publications

Fish assemblages in rivers of the Midwestern United States are an important component of the region's natural resources and biodiversity. We characterized the physical environment and presence of dams in a series of reaches in three eastern Iowa rivers tributary to the Mississippi River and related these characteristics to the fish assemblages present. Some physical characteristics were similar among the 12 study reaches, whereas others differed substantially. We found a total of 68 species across the 12 study reaches; 56 in the Turkey River, 51 in the Maquoketa River and 50 in the Wapsipinicon River. Seventeen species could be ...


Factors Affecting Burrowing Owl Occupancy Of Prairie Dog Colonies, Kristen M. Alverson, Stephen J. Dinsmore Apr 2014

Factors Affecting Burrowing Owl Occupancy Of Prairie Dog Colonies, Kristen M. Alverson, Stephen J. Dinsmore

Natural Resource Ecology and Management Publications

Understanding patch dynamics can help scientists better understand metapopulations and the relationships of animals that share a habitat. The Burrowing Owl (Athene cunicularia) is a well-known associate of prairie dog colonies, thereby linking conservation measures that benefit these species. We used occupancy modeling to determine how colony attributes (e.g., size and edge effects) and the loss of prairie dog colonies to sylvatic plague affected the occupancy of those colonies by Burrowing Owls in north-central Montana. We surveyed presence–absence of Burrowing Owls during a 13-yr period (1995–2007) and analyzed the data using a robust-design occupancy model in Program ...


Influence Of Landscape Characteristics On Retention Of Expandable Radiocollars On Young Ungulates, Troy W. Grovenburg, Robert W. Klaver, Christopher N. Jacques, Todd J. Brinkman, Christopher C. Swanson, Christopher S. Deperno, Kevin L. Monteith, Jaret D. Sievers, Vernon C. Bleich, John G. Kie, Jonathan A. Jenks Mar 2014

Influence Of Landscape Characteristics On Retention Of Expandable Radiocollars On Young Ungulates, Troy W. Grovenburg, Robert W. Klaver, Christopher N. Jacques, Todd J. Brinkman, Christopher C. Swanson, Christopher S. Deperno, Kevin L. Monteith, Jaret D. Sievers, Vernon C. Bleich, John G. Kie, Jonathan A. Jenks

Natural Resource Ecology and Management Publications

One tool used for wildlife management is the deployment of radiocollars to gain knowledge of animal populations. Understanding the influence of individual factors (e.g., species, collar characteristics) and landscape characteristics (e.g., forested cover, shrubs, and fencing) on retention of expandable radiocollars for ungulates is important for obtaining empirical data on factors influencing ecology of young-of-the-year ungulates. During 2001–2009, we captured and radiocollared 198 white-tailed deer (Odocoileus virginianus) fawns, 142 pronghorn (Antilocapra americana) fawns, and 73 mule deer (O. hemionus) fawns in South Dakota, Minnesota, and California, USA. We documented 72 (36.4%), 8 (5.6%), and 7 ...


Influence Of Season And Time Of Day On Marsh Bird Detections, Tyler Harms, Stephen J. Dinsmore Mar 2014

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

Natural Resource Ecology and Management Publications

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 limicola), Sora (Porzana carolina), Common Gallinule (Gallinula ...


Disease And Predation: Sorting Out Causes Of A Bighorn Sheep (Ovis Canadensis) Decline, Joshua B. Smith, Jonathan A. Jenks, Troy W. Grovenburg, Robert W. Klaver Feb 2014

Disease And Predation: Sorting Out Causes Of A Bighorn Sheep (Ovis Canadensis) Decline, Joshua B. Smith, Jonathan A. Jenks, Troy W. Grovenburg, Robert W. Klaver

Natural Resource Ecology and Management Publications

Estimating survival and documenting causes and timing of mortality events in neonate bighorn sheep (Ovis canadensis) improves understanding of population ecology and factors influencing recruitment. During 2010–2012, we captured and radiocollared 74 neonates in the Black Hills, South Dakota, of which 95% (70) died before 52 weeks of age. Pneumonia (36%) was the leading cause of mortality followed by predation (30%). We used known fate analysis in Program MARK to estimate weekly survival rates and investigate the influence of intrinsic variables on 52-week survival. Model {S1 wk, 2–8 wks, >8 wks} had the lowest AICc (Akaike’s ...


Forest Recovery Patterns In Response To Divergent Disturbance Regimes In The Border Lakes Region Of Minnesota (Usa) And Ontario (Canada), Brian R. Sturtevant, Brian R. Miranda, Peter T. Wolter, Patrick M. A. James, Marie-Josée Fortin, Philip A. Townsend Feb 2014

Forest Recovery Patterns In Response To Divergent Disturbance Regimes In The Border Lakes Region Of Minnesota (Usa) And Ontario (Canada), Brian R. Sturtevant, Brian R. Miranda, Peter T. Wolter, Patrick M. A. James, Marie-Josée Fortin, Philip A. Townsend

Natural Resource Ecology and Management Publications

The persistence of landscape-scale disturbance legacies in forested ecosystems depends in part on the nature and strength of feedback among disturbances, their effects, and subsequent recovery processes such as tree regeneration and canopy closure. We investigated factors affecting forest recovery rates over a 25-year time period in a large (6 million ha) landscape where geopolitical boundaries have resulted in important land management legacies (managed forests of Minnesota, USA; managed forests of Ontario, Canada; and a large unmanaged wilderness). Stand-replacing disturbance regimes were quantified across management zones, both inside and outside a central ecoregion, using a time series of classified land ...


Prairie Strips: Bringing Biodiversity, Improved Water Quality, And Soil Protection To Agriculture, Lisa A. Schulte Moore Jan 2014

Prairie Strips: Bringing Biodiversity, Improved Water Quality, And Soil Protection To Agriculture, Lisa A. Schulte Moore

Natural Resource Ecology and Management Publications

The motivation for expanding the basket of goods that Midwestern farms produce is strong. While our current agricultural system achieves record productivity in crops and livestock, it is also associated with serious environmental shortcomings, including declines in water quality and biodiversity, increased flooding and greenhouse gas emissions, and even degradation of the foundation of agricultural productivity: the soil.


Historical Changes In Fish Assemblage Structure In Midwestern Nonwadeable Rivers, Timothy Parks, Michael C. Quist, Clay L. Pierce Jan 2014

Historical Changes In Fish Assemblage Structure In Midwestern Nonwadeable Rivers, Timothy Parks, Michael C. Quist, Clay L. Pierce

Natural Resource Ecology and Management Publications

Historical change in fish assemblage structure was evaluated in the mainstems of the Des Moines, Iowa, Cedar, Wapsipinicon, and Maquoketa rivers, in Iowa. Fish occurrence data were compared in each river between historical and recent time periods to characterize temporal changes among 126 species distributions and assess spatiotemporal patterns in faunal similarity. A resampling procedure was used to estimate species occurrences in rivers during each assessment period and changes in species occurrence were summarized. Spatiotemporal shifts in species composition were analyzed at the river and river section scale using cluster analysis, pairwise Jaccard's dissimilarities, and analysis of multivariate beta ...


Incorporating Detection Probability Into Northern Great Plains Pronghorn Population Estimates, Christopher N. Jacques, Jonathan A. Jenks, Troy W. Grovenburg, Robert W. Klaver, Christopher S. Deperno Jan 2014

Incorporating Detection Probability Into Northern Great Plains Pronghorn Population Estimates, Christopher N. Jacques, Jonathan A. Jenks, Troy W. Grovenburg, Robert W. Klaver, Christopher S. Deperno

Natural Resource Ecology and Management Publications

Pronghorn (Antilocapra americana) abundances commonly are estimated using fixed-wing surveys, but these estimates are likely to be negatively biased because of violations of key assumptions underpinning line-transect methodology. Reducing bias and improving precision of abundance estimates through use of detection probability and mark-resight models may allow for more responsive pronghorn management actions. Given their potential application in population estimation, we evaluated detection probability and mark-resight models for use in estimating pronghorn population abundance. We used logistic regression to quantify probabilities that detecting pronghorn might be influenced by group size, animal activity, percent vegetation, cover type, and topography. We estimated pronghorn ...