Arkansas Project: Conservation Outcomes in Great Plains Rangelands

Arkansas Project

Conservation Outcomes in Great Plains Rangelands

January 2021 - January 2023

Personnel

Caleb Roberts, Co-Principal Investigator

Participating Agencies

Arkansas Game and Fish Commisssion

For the past several decades, scientific research has quantified catastrophic outcomes to rangeland resources due to woody plant encroachment, including collapses in livestock production potential and rancher profitability, increasing risks of wildfire danger and water security, displacement of wildlife habitat, and losses to important social and community programs (e.g., revenue generated for public school education). However, scientific documentation of positive conservation management and strategy outcomes is limited. This leads to slower widespread adoption of 'winning' strategies. In this project, we leverage major advancements in monitoring technology (e.g., the Rangeland Analysis Platform) alongside various wildlife datasets to provide more rapid outcomes-generation for partners across the Great Plains. Quantifying spatially-explicit changes in rangeland productivity, cover, and state transitions is central to this approach and have served to better understand complex responses of more specialized outcomes-based assessments. This project is a collaboration between the Arkansas Cooperative Fish & Wildlife Research Unit, University of Montana, University of Nebraska-Lincoln, and Natural Resource Conservation Service (NRCS). Primary project deliverables are (1) a synthesis of existing NRCS technical guidance related to juniper encroachment in the Great Plains, (2) documentation improved management of productivity, cover, state transitions, and grassland wildlife diversity and abundance in the Great Plains. Timely documentation the benefits of new conservation practices will equip agencies and private lands managers to tackle the woody encroachment problem in the Great Plains.

Research Publications

Research Publications	Publication Date
Scott L. Morford, Brady W. Allred, Dirac Twidwell, Matthew O. Jones, Jeremy D. Maestas, Caleb P. Roberts, David E. Naugle. Herbaceous production lost to woody encroachment in U.S. rangelands. Journal of Applied Ecology. https://doi.org/10.1111/1365-2664.14288 \| Abstract	October 2023	Rangelands of the United States provide ecosystem services that sustain biodiversity and rural economies. Native tree encroachment is a recognized and long-standing conservation challenge to these landscapes, but its impact is often overlooked due to the slow pace of tree invasions and the positive public perception of trees. Here we show that tree encroachment is a dominant change agent in U.S. rangelands; tree cover has increased by more than 76,000 km2 over 30 years, and more than 25% of U.S. rangelands are now experiencing sustained tree cover expansion. Further, we use machine learning methods to estimate the potential herbaceous production (forage) lost to tree encroachment. Since 1990 roughly 315 Tg of herbaceous biomass has been lost, totaling some $5 billion in foregone revenue to agricultural<br>producers. These results suggest that tree encroachment is similar in scale and magnitude to row-crop conversion, another primary cause of rangeland loss in the U.S. Prioritizing conservation efforts to prevent tree encroachment in rangelands can bolster ecosystem and economic sustainability of these landscapes, particularly among privately-owned lands threatened by land-use conversion.
Roberts, C. P., Scholtz, R., Fogarty, D. T., Twidwell, D., & Walker Jr, T. L. (2022). Large‐scale fire management restores grassland bird richness for a private lands ecoregion. Ecological Solutions and Evidence, 3(1), e12119. \| Abstract \| Download	January 2022	Of all terrestrial biomes, grasslands are losing the most biodiversity the most rapidly, so there is a critical need to document and learn from large-scale restoration successes. In the Loess Canyons ecoregion of the Great Plains, USA, an association of private ranchers and natural resource agencies has led a multi-decadal, ecoregion-scale initiative to combat the continued loss of grasslands to woody plant encroachment by restoring large-scale fire regimes. Here, we use 14 years of fire treatment history with 6 years of grassland bird monitoring and remotely-sensed tree cover data across 136,767 hectares of privately-owned grassland to quantify outcomes of large-scale grassland restoration efforts. Grassland bird richness increased across 65% (90,032 ha) of the Loess Canyons, and woody plant cover decreased up to 55% across 25% (7,408 ha) of all fire-treated areas. This was accomplished with extreme fire treatments that killed mature trees, were large (mean annual area burned was 3,100 ha), spatially clustered, and straddled boundaries between invasive woodlands and remaining grasslands—not heavily-infested woodlands. Findings from this study provide the first evidence of human management reversing the impacts of woody encroachment on grassland birds at an ecoregion scale.
Roberts CP, Ludwig A, Fogarty DT, Stuber E, Uden DR, Walker TJ, Twidwell D. *Population increases of the threatened American burying beetle (Nicrophorus americanus) linked to large-scale conservation strategies in a private lands ecoregion*. Biological Conservation. 301: https://doi.org/10.1016/j.biocon.2024.110865 \| Abstract	November 2024	Woody plant encroachment and row-crop agricultural land conversion are existential threats to species that rely on grassland ecosystems. The American burying beetle (<i>Nicrophorus americanus</i>) is a threatened species whose largest remnant populations are predominantly located in grassland ecoregions comprised of privately-owned ranching lands. Here, we seek to determine functional scaling patterns and population trends of the American burying beetle in the face of conservation threats and grassland restoration. We used 13 years (2007 – 2019) of American burying beetle abundance data collected from permanent sampling locations across the Loess Canyons ecoregion (Nebraska, USA), where a network of ranchers have been restoring large-scale grasslands. To estimate beetle abundance relative to land cover variables, we developed a Bayesian N-mixture model, incorporating the Bayesian latent indicator scale selection (BLISS) method to probabilistically determine at which scales land cover variables best explained beetle abundance. American burying beetle abundance significantly increased across the ecoregion, despite high interannual variation in abundance. Increases in beetle abundance were associated with large-scale (1,149 ha extent) grassland cover. Decreases in abundance were associated with large-scale crop conversion (590 ha extent) and large-scale increases in woody cover (1,149 ha extent). This study provides the first evidence of ecoregion-scale population increases of the American burying beetle. These increases are tied to landscape variables that are managed in a large-scale, coordinated private lands grassland restoration effort. Our results suggest that successful grassland restoration will depend on coordinating across property boundaries to implement conservation at scales necessary to conserve species that require large-scale, unfragmented grasslands.

Presentations

Presentations	Presentation Date
Roberts CP, Cady SM, Donovan VM, Fogarty DT, Scholtz R, Twidwell D, Uden DR. 2024. Successes, challenges, and scientific advances gleaned from ecoregion-scale grassland restoration in the Loess Canyons, Nebraska. Society for Range Management 2024 Annual Meeting. Sparks, NV.	January 2024

Cooperative Fish and Wildlife Research Units Program: Arkansas Education, Research and Technical Assistance for Managing Our Natural Resources