Conservation potential of existing lawns: enhancing and replacing lawns with native plants for biodiversity and ecosystem function in urban plant communities of chicago

This National Science Foundation (NSF) Biological Sciences (CFDA 47.074) Project Grant award of $897,744 to the Chicago Horticultural Society (Chicago Botanic Garden) supports research to assess the conservation potential of enhancing and replacing urban turfgrass lawns with native plants. The key objectives are to: 1) quantify the ecosystem service benefits of converting lawns to native plant communities, focusing on supporting pollinators, stormwater management, urban cooling, and carbon storage; and 2) determine which native species can be effectively incorporated into existing lawns to enhance biodiversity and ecosystem function. The project will involve in-situ experiments in Chicago parks as well as controlled greenhouse studies to evaluate native plant establishment and performance. The results will inform strategies for municipal park managers and homeowners to convert or augment lawns with native vegetation to promote urban biodiversity and ecosystem services. This 5-year project is set to commence on October 1, 2024.

Abstract

Turfgrass lawns are the largest irrigated crop in the united states by land cover. Astounding amounts of water are used in their maintenance, herbicides and pesticides deliberately reduce the diversity of plants and animals, and mowing gas consumption actively contributes to climate change. Nonetheless, lawns are pre-existing greenspaces that hold extraordinary potential for biodiversity conservation. How can these spaces be changed to better serve the natural world and people? This project proposes native plant alternatives to enhance and replace lawns and will collect data to quantify the potential benefits of making the change. Introducing native lawn alternative plantings may contribute to ecosystem services that are important in urban systems, such as supporting pollinators and other wildlife, absorbing stormwater, and cooling cities, while providing refuge for native plants of our region. This project will actively enhance turfgrass lawns in chicago area parks, collect data on the impacts of lawn conversion and enhancement, and help train scientists for research and applied conservation careers. Lawns are landscapes that decision-makers, big and small, have the power to change, from park districts to individual homeowners. Communication about the benefits of lawn alternatives is central to this work. To this end, learning gardens supported by interpretive signage will be planted in highly visited chicago area parks and broad communication strategies through digital and print media will demonstrate the benefits of lawn alternatives to the public. This project will develop evidence-based conservation planning through paired research and conservation goals dedicated to 1) understanding ecosystem service benefits associated with different urban greenspaces to explore possibilities of lawn conversion to short native plants, and 2) determining which native species could be used in low-input enhancement of turfgrass lawns. First, the results of in situ and controlled experiments will help to untangle the relationships between biodiversity and ecosystem function in urban plant communities. Researchers will measure ecosystem service (ES) provisioning, with a focus on a) supporting native plants and pollinators, b) stormwater infiltration, c) urban cooling, and d) carbon storage. We will evaluate these ES in extant urban parks within the chicago park district (CPD), one of the largest municipal park managers in the united states (over 8,800 acres), and in common garden experiments with replicated plots that represent an array of potential options for lawn conversion. This project will additionally advance the understanding of community assembly theory by studying how seed traits predict species emergence and establishment in existing turfgrass systems. To study the potential use of native species for lawn enhancement, phylogenetic lineage and functional traits of seeds of native tallgrass prairie species will be used to predict their ability to establish an existing lawn in a replicated greenhouse experiment. Finally, species that establish well from the greenhouse experiment will be planted into existing lawns within the CPD to assess field establishment while enhancing existing lawns. This project is jointly funded by the divisions of environmental biology and integrative organismal systems through the partnership to advance conservation science and practice program. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the foundation's intellectual merit and broader impacts review criteria.- subawards are planned for this award.