Grassland monitoring protocol for the Southern Plains I&M Network and Fire Group: Narrative Version 1.00

Folts-Zettner, Tomye; Gatewood, Richard; Bennetts, Robert; Sosinski, Heidi

The parks of the Southern Plains Network (SOPN) are dominated by mid- and shortgrass prairies that have been impacted by grazing, fire suppression and rowcrop agriculture. Individual restoration efforts of varying techniques and duration have been employed in the past in most of these parks with mixed results. Monitoring of these efforts has been minimal. This grassland vegetation monitoring protocol has been developed to inform park management of the status and trends of the overall health of their grasslands and to provide some information on the effectiveness of restoration efforts. Collaboration with the Southern Plains Fire Group (SPFG) fire effects monitoring program has been developed to address broader issues of vegetation health and to achieve economic efficiencies in both programs. This protocol reflects this collaboration. North American prairie once extended across the mid-continent region from Canada to Texas and from the Rocky Mountains to the Appalachian forest. The vast landscape was nearly continuous grassland, transitioning gradually from shortgrass steppe in the west to tallgrass prairie and savanna in the east. During the last century, large portions of grassland landscapes were plowed for cropland or converted to livestock pasture. Today, Great Plains grasslands are fundamentally altered by the conversion of prairie to cropland and pasture, the removal or disappearance of native ungulates, drainage of wetlands, and an increase in woody vegetation through plantings and fire suppression. Scientists estimate that the loss of native prairie ranges from 80 to 99.9%, with the greatest losses occurring in the tallgrass prairie and oak savanna communities. Further, only 71% of shortgrass prairie and 59% of mixedgrass prairie remain (Knopf and Samson 1997). Fragmentation and isolation continues today at an alarming rate. The nature of the above-ground plant community (e.g., the diversity of species andfunctional guilds) plays an important role in determining the stability or resistance to disturbance of a prairie system (Wardle et al. 2000). Prairies are dominated by a few matrix-forming grass species that effectively control community structure. A large number of less abundant species, referred to as satellite species, contribute to the diversity of prairie systems (Collins 1987, Collins and Glenn 1988, Collins and Glenn 1990). Distribution patterns of these satellite species are inherently bimodal, varying within and between growing seasons (Collins and Glenn 1988, Collins and Gibson 1990). Ecological driving forces such as fire and the presence of native faunal species including bison (Bos bison), elk (Cervus elaphus), and wolves (Canis lupus), remain largely absent from prairie systems, having been eliminated or placed under human control. Domesticated animals have replaced only some of the services once supplied by these drivers and most parks in the southern Plains do not currently allow grazing. This change in grazing regime can lead to changes in plant community structure and nutrient cycling. Fire frequency and seasonality plays a large role in the ecology of the Great Plains. Frequent fire is essential to maintaining native species diversity, and it affects other components, including nutrient cycling and productivity (Collins and Wallace 1990). Historically, lightning and Native Americans were the principal causes of fire. SOPN parks generally average between 40 and 50 days with thunderstorms per year (Bryson and Hare 1974) and fire ignited by summer storms occurred May through September (75% of these between July and August) when storms are most common (Bryson and Hare 1974). In the southern mixedgrass prairie, Native Americans appeared to use fire most frequently in July and August (Moore 1972).

Grassland monitoring protocol for the Southern Plains I&M Network and Fire Group: Narrative Version 1.00

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