RESTORATION OF EVOLUTIONARY FIRE-GRAZING INTERACTIONS TO LIMIT INVASION OF EXOTIC FORAGES IN THE CENTRAL GRASSLANDS

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: COMPLETE
• Funding Source: HATCH
• Reporting Frequency: Annual
• Accession No.: 0215350
• Project Start Date: Jun 1, 2008
• Project End Date: Aug 31, 2010
• Program Code: [(N/A)]- (N/A)

Recipient Organization
IOWA STATE UNIVERSITY
2229 Lincoln Way
AMES,IA 50011

Performing Department
Ecology, Evolution, and Organismal Biology

Non Technical Summary
North American prairie ecosystems evolved in the context of both fire and grazing. In recent efforts to restore the fire-grazing interaction to these grasslands, fire is applied to discrete portions of the landscape and grazers focus their activities on recently burned patches while avoiding unburned areas. This approach is termed ?patch-burn grazing.? The scale of forage selection is altered from individual plant species to entire patches and the interaction increases biodiversity and limits the spread of exotic, invasive forage species and woody encroachment. Our goal is to test the use of patch-burn grazing and compare this to traditional grazing or the use of fire without grazing. We focus on plant-herbivore interactions and the disturbance patterns created by the fire-grazing interaction that alters livestock selectivity and competitive relationships among plants. We will examine the responses of insects and songbirds to these different management approaches. We will also work with local landowners to examine their perspectives on the use of fire and grazing as management tools in Iowa grasslands and Oak Savannas.

Animal Health Component

70%

Research Effort Categories

Basic

30%

Applied

70%

Developmental

(N/A)

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
121	0799	1070	10%
121	1629	1070	20%
121	3090	1070	10%
121	3110	1070	10%
136	0799	1070	20%
136	1629	1070	10%
136	3090	1070	10%
136	3110	1070	10%

Knowledge Area
136 - Conservation of Biological Diversity; 121 - Management of Range Resources;

Subject Of Investigation
0799 - Rangelands and grasslands, general; 1629 - Perennial grasses, other; 3090 - Other Pollinators; 3110 - Insects;

Field Of Science
1070 - Ecology;

Keywords

ecosystem management

grazing management

heterogeneity

rangelands

fire

equilibrium

ecology

native range

spatial distribution

temporal distribution

structural properties

functional properties

biodiversity

disturbed areas

fire dependent ecosystems

vegetation

environmental models

ungulates

soil plant animal relations

Goals / Objectives
Introduced forage species planted as monocultures often possess traits that promote persistence under intense grazing by domestic and native herbivores. Rapid maturation, secondary chemicals, and fungal associations are among the traits that enhance persistence and can facilitate dominance over native plants that are preferentially selected by native and domestic herbivores. Forages native to North American evolved under a fire-grazing interaction (i.e., the evolutionary disturbance pattern) whereas many introduced forage plants evolved under heavy grazing pressure without the fire interaction. In recent studies that restore the fire-grazing interaction to North American grasslands, fire is applied to discrete portions of the landscape and grazers congregate and intensively graze recently burned patches but avoid unburned areas. Scale of forage selection is altered from individual species to entire patches and the interaction increases biodiversity and limits the spread of an exotic, invasive forage species. These preliminary results suggest that native species might be better adapted to the evolutionary disturbance pattern than the introduced forage species that are invading under traditional management that lacks the evolutionary disturbance pattern. Therefore, our goal is to focus on the plant-herbivore interactions of invasive forage species in diverse native plant communities and the evolutionary disturbance pattern created by the fire-grazing interaction that alters livestock selectivity and competitive relationships among plants. We will focus on four functionally different introduced forage species, all invading native grasslands and all adapted to grazing through mechanisms that limit palatability. Our specific objectives are:1. evaluate invasive plant selectivity and response to herbivory within species rich grasslands 2. determine whether alterating grazing pattern through the fire-grazing interaction decreases exotic plant invasion rate when compared to traditional management in agroecosystems 3. determine the effect of grazing patterns and plant invasion on native invertebrate herbivores 4. determine the role of landscape context relative to the fire-grazing interaction on forage species invasions and response of native invertebrates to fire and grazing. We will address these objectives across a climate gradient from the southern mixed prairie of Oklahoma to the prairie peninsula of Iowa. We plan to focus on four invasive forage species that are functionally diverse and have variable persistence mechanisms contributing to their invasion in mixed species agroecosystems. These invasive species were introduced as forage species and possess survival and persistence traits under grazing. The species that we are proposing for study are sericea lespedeza (perennial legume, high tannin levels), Old World bluestem (C4 grass, high stem-to-leaf ratio, rapid maturation), tall fescue (C3 grass, fungal endophyte), and reed canarygrass (C3 grass, rapid maturation).

Project Methods
Most approaches to managing native ecosystems are based on an equilibrium paradigm that rarely considers spatial or temporal variability within an ecosystem (Fuhlendorf and Engle 2001, Briske et al. 2003). Understanding spatial and temporal variability inherent within ecosystems or associated with variable patterns of disturbance can be critical in describing and managing the structure and function of ecosystems. In fact, heterogeneity may actually be the root of biological diversity at all levels of ecological organization and should serve as the foundation for conservation and ecosystem management (Christensen 1997, Ostfeld et al. 1997, Wiens 1997). Therefore, it is important that we develop management approaches that apply state-of-the-art ecological theories that incorporate an understanding of spatial and temporal variability in the structure and function of ecosystems. In grassland ecosystems, such as those in the Great Plains of North America that evolved with fire and ungulate grazing, the frequency and intensity of disturbances are critical to ecological processes, biological diversity, and heterogeneity across multiple spatial scales (Collins 2001). However, most research of the effects of these processes has focused on main effects of grazing and fire with little or no attention given to their interaction in space and time. A model of the grazing-fire interaction (grazing-fire model) argues that grazing and fire interacting through a series of positive and negative feedbacks to cause a shifting mosaic of vegetation pattern across the landscape may have been critical in the evolution of Great Plains grasslands (Hobbs et al 1991, Fuhlendorf and Engle 2001). According to the model, probability of fire is greatest on areas with high biomass accumulation within a grazed grassland landscape. A positive feedback occurs when a recent fire event attracts grazing animals, which further disturbs the site. On tallgrass prairie landscapes grazed by bison, the most recently burned patches are preferentially selected when bison are free to select from a diverse landscape that includes patches with variable fire histories (Coppedge et al 1998a, Coppedge and Shaw 1998). Responses to experimental treatments will be assessed by conducting plant and insect distribution and abundance surveys within each experimental pasture. Pastures will be subdivided into patches with varying treatments (burn, graze, patch-burn). We will sample vegetation in permanently marked modified Whittaker plots (Stohlgren et al. 1998). Abundance data will be collected annually for invertebrates in each of the patches from mid-June to mid-August. Sampling at each site will be temporally spaced to cover the major emergence periods within the summer (June-July and July-Aug), and each patch will be surveyed twice per year via sweep netting.

Progress 06/01/08 to 08/31/10

Outputs
OUTPUTS: This grant has served as the basis of several other proposals that have been funded. We have given many invited and contributed presentations at scientific and professional conferences. Topics included effects of the fire grazing interaction on agriculture, biological diversity and invasive species. Audiences included land owners, land managers, agency representatives and other scientists were in attendance at each meeting. The patch-burn working group met again this year in Oklahoma. It is a group of researchers and managers that meets once a year to determine progress and challenges associated with their efforts. This working group was put together based on the seminal research connected to this project and includes representatives from Oklahoma, Kansas, Missouri, Iowa, Nebraska, Colorado, Texas and other areas. We met at the Tallgrass Prairie Preserve and all of our students from Oklahoma State University and Iowa State University gave presentations. Our team gave the following invited and contributed presentations at professional meetings: *D.M. Debinski. Butterfly Movement and Habitat Use in Highly Fragmented Landscapes. Symposium: Butterfly dispersal - linking ecology to conservation, linking observation to theory. 6th International Conference on the Biology of Butterflies, Edmonton, Alberta, June 29, 2010. *D.M. Debinski. Butterfly Movement and Habitat Use in Highly Fragmented Landscapes. Iowa Pollinator Conservation Short Course. Reiman Gardens and Xerces Society, Aug. 10, Ames, IA, 2010. *D.M. Debinski. Butterfly community responses to land use management in native and restored prairies. Natural Resources Ecology and Management. ISU, Ames, IA, Jan 29, 2010. *McGranahan, D.A. D.M. Engle, J.R. Miller, and D.M. Debinski. 2010. Disturbance history and dominant invaders affect exotic-native plant diversity in a grassland system. Midwest Ecology and Evolution Conference. Ames, IA. March 27. *Miller, J., L. Morton, D. Engle, D.M. Debinski, R. Harr. Reserves-as-Catalysts Model: Expanding the Influence of Public Lands. Society for Range Management and Weed Science Society of America, Denver, Colorado, February 7-11, 2010. *McGranahan, D., D. Engle, S. Fuhlendorf, J. Miller, and D.M. Debinski. Grazing history, soil carbon, and invasion by an exotic cool-season grass explain extraordinary community diversity in a working prairie landscape. Society for Range Management and Weed Science Society of America, Denver, Colorado, February 7-11, 2010. Faculty and graduate students gave 16 additional presentations at scientific and professional meetings. 6 workshops and field days were conducted to present results from this project. PARTICIPANTS: Oklahoma State University; Oklahoma Agricultural Experiment Station; Department of Natural Resource Ecology and Management, Oklahoma State University; Iowa State University Extension; Sam Fuhlendorf, Professor, Oklahoma State University; Karen Hickman, Associate Professor, Oklahoma State university; Diane Debinski, Professor, Iowa State University; James Miller, Associate Professor, University of Illinois; David Engle, Professor, Oklahoma State University; Lois Wright-Morton, Professor, Iowa State University; Ryan Limb, Research Associate, Oklahoma State University; Chad Cummings, Research Associate, Oklahoma State University; Ryan Harr, Research Technician, Iowa State University; Brady Allred, Graduate Student, Oklahoma State University; Scott Robertson, Graduate Student, Oklahoma State University; Ray Moranz, Graduate Student, Oklahoma State University; Torre Hovick, Graduate Student, Iowa State University; Devan McGranahan, Graduate Student, Iowa State University; Finn Pillsbury, Graduate Student, Iowa State University; Elise Regen, Graduate Student, Iowa State University; 14 undergraduate students. TARGET AUDIENCES: Land owners, Federal agencies that work with land owners, Federal agencies that manage land, Non-governmental agencies. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
There are over 50,000 non-indigenous species in the United States that cause major environmental damage and losses totaling approximately $137 billion per year. Some of these non-indigenous species are from intentional introductions of plants for agricultural or horticultural purposes. Our project focused on managing exotic species that were introduced as forages and have become invasive on rangeland ecosystems. We argue that these species are unique because they were introduced for grazing as monocultures but are invading rangelands causing environmental problems and diminishing the economic value of production on these ecosystems. Our project focuses on using combinations of burning and grazing to alter distribution and species selection of herbivores to control the rate of invasion from 4 species in the central Grasslands of North America. The largest difference we found was between grazing and no grazing, but because livestock grazing is a common enterprise on most farms in Iowa, we are also interested in comparing the two grazing (patch-burn grazing and burn-and-graze) treatments. For the two grazing treatments between 2006 and 2009, the spatial interaction of fire and grazing (patch-burn grazing) had no advantage over uniform grazing because of heavy stocking. Therefore, we plan to continue the study under more moderate stocking. This project has led to the development of new options for cost share through the Environmental Quality Incentives Program (EQIP) through USDA-NRCS. From 1997 to 2002, EQIP has entered into 117,625 contracts on more than 51.5 million acres and obligated nearly $1.08 billion to help land owners advance stewardship on working agricultural lands. Additionally, we have educated individual land owners, as well as agency employees from the NRCS, USFS, USFW, BLM and numerous state agencies throughout Texas, Oklahoma, Kansas, Missouri, Iowa, Nebraska, Colorado, Wyoming, New Mexico and other states. Many of these individuals have altered their actions and have begun to practice our approach to managing rangelands. In Iowa, we interacted closely with 6-8 landowners who owned or leased land and four cattle producers who provided cattle for the project work. Iowa DNR has begun adopting forms of PBG as a practice on grasslands across the state (~2,250 acres), as has USFWS (a few hundred acres). Our project also involved programming for perhaps 600-700 more landowners and operators over the course of the project period. Numerous private land owners have applied our research to their landscapes to more efficiently control invasive species, enhance biological diversity and sustain livestock production.

Publications

• Fuhlendorf, SD, DW Townsend II, RD Elmore, DM Engle. 2010. Pyric Herbivory to promote rangeland heterogeneity: Evidence from small mammal communities. Rangeland Ecology and Management 63:670-678.
• Orlofske J.M., W.J. Ohnesorg, D.M. Debinski. 2010. Potential Terrestrial Arthropod Indicators for Tallgrass Prairie Restoration in Iowa. Ecological Restoration 28(3):250-253.

Progress 01/01/09 to 12/31/09

Outputs
OUTPUTS: This project focuses specifically on insect responses to burning, grazing, and patch-burn grazing treatments within the Grand River Grassland of southern Iowa. Research-related activities included data collection via transect surveys for butterflies and sweep net surveys for insects. Sweep net samples are being sorted generally to the family level, although some groups are being identified to genus or species when possible. Two honors undergraduate students, one independent study undergraduate student, two Science with Practice interns, and one graduate student were mentored as part of this project during the past year. Events accomplished during the past year include several presentations at scientific conferences listed below, and field day held in May, 2009 for members of the Iowa Department of Natural Resources and a member of the Fish and Wildlife Service; another field day was held in late September, 2009 in conjunction with a patch-burn grazing meeting for scientists, non-profit organization representatives, and managers from several states with an interest in grassland management. The Leopold Center for Sustainable Agriculture interviewed several of our PIs at our research site during the fall and is in the process of making an educational video summarizing our work. Presentations: Debinski, D.M., L. Merrick, R. Moranz, D. Engle, R. Harr, and J. Miller. Insect responses to Patch-Burn Grazing in Prairie Ecosystems. Iowa Chapter of The Wildlife Society, Ames, IA Jan 28, 2009. Debinski, D.M. Butterfly community responses to land use management in native and restored prairies. Symposium on Pollinator Diversity in Urban, Agricultural and Native Landscapes. Entomological Society of America. Indianapolis, Indiana. Dec. 13-16, 2009. Engle, D.M., J.R. Miller, L.W. Morton, D.M. Debinski, and R.N. Harr. 2009. A model for returning prescribed burning to working lands of the Midwest. Fourth International Congress on Fire Ecology and Management: Fire as a Global Process. Savannah, GA, USA. Nov. 30-Dec. 4, 2009. Debinski, D.M., L. Merrick, R. Moranz, D. McGranahan, D. Engle, J. Miller, and R. Harr. Landscape Memory and the Assessment of Fire and Grazing Effects on Prairie Insect Biodiversity. International Association of Landscape Ecologists meeting, Snowbird, UT, April 12-16, 2009. Miller, J.R., L. Wright Morton, D. Engle. D.M. Debinski, R. Harr. Ecological restoration as a catalyst for landscape change. U.S. Regional Association of the International Association for Landscape Ecology 24th Annual Symposium, April 2009, Snowbird, Utah. PARTICIPANTS: Individuals who worked on the project: Diane M. Debinski, Department of Ecology, Evolution, and Organismal Biology, Iowa State University. James R. Miller, Department of Natural Resources and Environmental Sciences, University of Illinois, Urbana. David M. Engle, Department of Natural Resource Ecology and Management, Oklahoma State University, Stillwater. Ryan N. Harr, Department of Natural Resource Ecology and Management, Iowa State University. Samuel D. Fuhlendorf (collaborator working on Oklahoma site), Natural Resource Ecology and Management, Oklahoma State University, Stillwater. Karen Hickman (collaborator working on Oklahoma site), Natural Resource Ecology and Management, Oklahoma State University, Stillwater. Partner Organizations: Since the inception of the project, our project team has collaborated with a diverse array of state, federal, and local agencies, non-governmental organizations, and private citizens. These entities include the U.S. Fish & Wildlife Service, USDA Natural Resources Conservation Service, The Iowa and Missouri Chapters of the Nature Conservancy, Missouri Department of Conservation, and the Leopold Center for Sustainable Agriculture. Collaborators have likewise aided our research group with work on experimental pastures and by helping to cultivate relationships with landowners throughout the greater Grand River Grasslands. TARGET AUDIENCES: Land management agency personnel (e.g., state Departments of Natural Resources or Conservation, the U.S. Fish and Wildlife Service), ecologists, rangeland scientists, non-profit environmental groups such as the Nature Conservancy and the Leopold Center for Sustainable Agriculture, and local landowners are our target audience. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Our Iowa project has received quite a bit of attention locally and the Iowa Department of Natural Resources has become interested in considering the use of patch-burn grazing on some of its lands outside of our study sites. However, we are are not yet ready to release prescriptive management statements based upon our treatments. Due to factors beyond our control, grazed treatment pastures were stocked excessively before and after our project was implemented, and the patch-burn grazing treatment has not yet resulted in the expected increased habitat heterogeneity. To fully evaluate the responses, we are currently seeking additional funds which would allow us to continue this research with the grazed pastures being stocked more moderately.

Publications

• No publications reported this period