Old-Growth Grasslands Network
Old-Growth Grassland remnants are natural benchmarks for guiding management and restoration in North America’s grasslands
What are Old-Growth Grassland Remnants?
Old-growth grasslands are unique in having never been plowed or overgrazed. With > 90% of former grasslands converted to agriculture globally, few old-growth grasslands remain. In the U.S., they exist in only a few places – as small remnants in preserves, in cemeteries, along fence rows, or in a few well-managed rangelands. These remnants are unique windows into the natural ecosystem, providing a powerful opportunity to understand the biophysical processes that made natural grasslands highly productive, biodiverse, and drought-resilient ecosystems.
Why are soils the priority?
Historically grasslands had dense vegetation that extended up to several meters both above and below the ground surface. This grassland system was ideally adapted to thrive in semi-arid climates, receiving <600 mm of rainfall a year. Aboveground foliage intercepted the scarce rainfall and morning dew, funneling it to the soil water reservoir below. Decaying leaves formed an insulating mulch across the soil surface, and beneath it the decomposing leaves and roots formed deep, sponge-like organic matter that stored rainwater for use by plants during dry periods. This system was resilient to droughts, thriving without augmentation by irrigation. Recently, genetic analyses of soil microbes suggest that OGGRs may also be invaluable repositories of diverse and unique microbial communities that are critical to restoring healthy grasslands.
What role do they play in biodiversity?
When surrounded by cornfields, it is difficult to visualize that grasslands were once a richly diverse and productive living ecosystem extending across the North American continent. Foliage provided food for bison and other mammals, and habitat for birds. Grasses intermingled with diverse plants which alternated flowering throughout the seasons – a colorful garden supporting untold numbers of butterflies and other pollinators. Interwoven root and soil systems were equally productive and provided food and burrows for rodents as well as the predators which depended on them. Together these organisms formed a complex, diverse food web which was highly resilient to droughts, fire and other disturbances. Old-growth grassland remnants simultaneously provide glimpses of this once vibrant landscape and are refugia or steppingstones for many organisms currently moving across an otherwise inhospitable landscape.
OGG Remnant Maps and Info
Development of the OGG map and database is underway!
- The primary resource is a map of OGG remnants and the associated information available for each site. The yellow dots show the locations of a subset of the ~300 sites currently in the database. This map, and the associated soil data, will become interactive in spring, 2024.
- For each site, available photos and data will be provided on different aspects of soil health and protection status of the remnant.
Selected remnant and soil health properties from east Nebraska:
Average of 5 sites (+/- 1 St. Dev.)
(data from Kurtz 2021, Cornell University, CALS Soil Health Lab for protocols)
- Biological:
- Soil organic carbon 5.54% (0.85)
- Respiration rate 1.04 mg CO2/g soil (0.24)
- Active carbon 762.7 ppm (122.7)
- Physical:
- Aggregate stability 59.6% (15.86)
- Avail. water-holding capacity 0.45 g/g (0.35)
- Chemical:
- pH 6.83 (0.78)
- Total N 0.27 g/100g (0.06)
- Phosphorus 2.39 ppm (0.85)
How can you become part of the OGGN?
Investigate a remnant near you!
Add a new remnant to the database!
Collect and submit OGG soil samples for comprehensive soil health analyses.
Look out for our flowering forbs photo competition in 2024!
Who is the OGGN leadership team?
- Cornell University, New York:
- Rebecca Schneider, PhD
- Harold Van Es, PhD
- Andrew Trlica, PhD
- Stephen Morreale, PhD
- https://soilhealthlab.cals.cornell.edu/
- Central Grasslands Roadmap, Colorado – https://www.grasslandsroadmap.org
- Tammy VerCauteren
- Matt Gray
Contact: RLS11@cornell.edu
Stay tuned for updates and changes over the months.
Last update 27 October 2024