CONSERVATION GRAZING WITH CATTLE: EVALUATING CONTROL OF WOODY ENCROACHMENT, PLANT COMMUNITY CHANGE AND GRASSLAND BIRD HABITAT by Laura E. Judge A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science (Agroecology) at the UNIVERSITY OF WISCONSIN-MADISON 2020 i Table of Contents Acknowledgements ....................................................................................................................... ii Land acknowledgement ................................................................................................................ v Chapter 1: Conservation grazing with cattle and control of woody encroachment in temperate cool-season grasslands in Wisconsin ......................................................................... 1 Abstract ...................................................................................................................................... 1 Introduction ............................................................................................................................... 2 Materials and Methods ............................................................................................................. 7 Results ...................................................................................................................................... 12 Discussion ................................................................................................................................. 14 Management Implications ...................................................................................................... 21 References ................................................................................................................................ 22 Figures ...................................................................................................................................... 27 Supplementary Table .............................................................................................................. 32 Chapter 2: Plant community and grassland bird habitat response to rotational grazing in conservation grasslands in Wisconsin ....................................................................................... 33 Abstract .................................................................................................................................... 33 Introduction ............................................................................................................................. 34 Materials and methods............................................................................................................ 36 Results ...................................................................................................................................... 40 Discussion ................................................................................................................................. 41 Management Implications ...................................................................................................... 48 Literature cited ........................................................................................................................ 49 Figures ...................................................................................................................................... 54 Tables........................................................................................................................................ 59 Chapter 3: Weighing trade-offs on grazing farms: forage quality and yield versus grassland bird habitat refuge ..................................................................................................... 64 ii Acknowledgements This work would not have been possible without the collaborative effort and support of so many people. First and foremost, my thanks go to my advisor, Mark Renz, for providing mentorship and guidance combined with autonomy and freedom to explore my interests as they evolved throughout my time as a graduate student. My heartfelt gratitude also extends to my committee members, Laura Paine and Randy Jackson, who always provided help when I asked and pushed me to expand my thinking. From my advisor, committee and the Agroecology program as a whole, I learned as much as I had hoped, as well as many lessons I had not anticipated and have gained, among many things, a whole new lens through which to view the world around me. For this, my life is changed for the better and I am forever grateful. Financial support was provided by a United States Department of Agriculture Hatch Grant and a graduate student grant from North Central Sustainable Agriculture Research and Education. I was also supported by the Dwayne Rohweder Forage Extension Fellowship through the Department of Agronomy and through the opportunity to teach with the Department of Integrative Biology. Many thanks go to the Renz lab for being a welcoming and supportive community, and especially to Jacob Grace for initiating the study, showing me the ropes and allowing me to hit the ground running when I arrived in Madison. I am also grateful for the support of Anne Pierce, Niels Jorgenson, Leo Roth, Jose Carvalho de Souza Dias, Will Osterholz, Jasmine Wyant and to the undergraduates who provided indispensable assistance in the field and lab: Erin Warner, Laura Miller, and especially Alicia Dixon, who proved herself up to every challenge and more. The Jackson Lab also provided essential support in lending equipment and expertise in equal iii measure, with special thanks to Greta Landis and Maggie Phillips. Support from the USDA Forage Research Center was also indispensable, especially from Jon Bleier and Kevin Panke- Buisse. Thanks also go to Alan Turnquist for wrangling the Hatch research group and keeping Agroecology program traditions alive and well. The research presented in Chapters 1 and 2 would not have been possible without the dedication of many partners outside the University. Land managers and staff at the Wisconsin Department of Natural Resources generously shared their time and equipment for setting up and maintaining treatment plots and remained dedicated to the collaboration over the timeframe of this study. I am especially grateful to Erin Grossman, Heidi Hayes, Julie Widholm, Zachary Knab, Lesa Kardash, Ryan Haffele, Jed Hopp, Dave Sample, Kent VanHorn and Mary C. Anderson. I am also forever indebted to the private livestock owners who made the grazing treatments possible and always returned my calls: William Kolodziej, Kevin Opperman and Larry and Marsha Croes. The Pasture Project provided the glue to stick all these partners together, help get the sites operational, and keep operations moving and evolving into the future, especially Pete Huff, Elizabeth Spratt and Rod Ofte. I owe the existence of the research presented in chapter 3 to the generosity, kindness and curiosity of Bill and Laura Paine and the Paine Family Farm. I am truly inspired by their dedication to both agriculture and conservation and to finding the synergies between the two. I am immeasurably lucky for the selfless mentorship of Laura Paine, who has been a role model and teacher for me in so many ways. Last but certainly not least, my unending gratitude goes to my family, friends, and furry friends. I would not be where I am today, nor be the person I am today, without the lifelong love iv and support I have received. Finally, I am lucky beyond words for my husband, Matt, for the partnership and patience. He weathered the ups and down with me and even managed to improve the weather each day, making it a bit brighter and sunnier. v Land acknowledgement In the work of ecological restoration, the history of the land cannot be ignored. Similarly, in the research of a land grant university, the history of stewardship of that land cannot be ignored. The University of Wisconsin-Madison occupies ancestral Ho-Chunk land, a place their nation has called Teejop since time immemorial. The Ho-Chunk were forced to cede this territory in an 1832 treaty and the federal and state government attempted to forcibly remove the Ho-Chunk from Wisconsin in the decades that followed. Today, UW-Madison respects the inherent sovereignty of the Ho-Chunk Nation, along with the eleven other First Nations of Wisconsin, and this history of colonization informs a shared future of collaboration and innovation. 1 Chapter 1: Conservation grazing with cattle and control of woody encroachment in temperate cool-season grasslands in Wisconsin Abstract Woody encroachment threatens grasslands worldwide, which in turn threatens grassland obligate wildlife. Mowing and herbicides are among the tools used to combat encroachment. Livestock grazing is another potential tool, although grazing methods vary widely and can sometimes exacerbate encroachment. We tested the potential to reduce woody plant cover and density with rotational grazing of cattle at low stocking density in three temperate cool-season grasslands. We implemented a completely randomized design on each of two pre-treatment levels of woody cover. Seasonal grazing was applied alone and in combination with two one-time woody suppression techniques (mowing and herbicide) applied in 2016. Each subsequent spring (2017 through 2019) we measured the response in total woody cover and stem size and density of individual woody species. We analyzed the most common species at each site: Quaking aspen (Populus tremuloides Michx.), white meadowsweet (Spiraea alba