Prairies

Unit Prairie Type Size
1 Intergrading Dry/Dry‐Mesic Prairie Remnant 30 acres
7 Mesic Prairie Remnant 8 acres
12 Dry Prairie Remnant 4 acres
14 Restored Prairie 4 acres
15 Wet‐Mesic Restoration (1998; expanded in 2003) 25 acres
20 West Valley Wet Prairie Restoration Planting (1997) 60 acres
21 Wet Prairie Restoration (1999) 8 acres
22 Dry Prairie Remnant 1.5 acres
26 (Brooks Property) Restored Prairie (2006; expanded in 2007) 10 acres
28 (Brooks Property) Restored Prairie (2008) 1.75 acres
31 Restored Prairie (2008) 2 acres

Total Area:                                   142.50 acres

Remnant                                           43.50 acres

Restored                                           99.00 acres

The term grassland is collectively applied to any plant community that exhibits a lack of trees and tall shrubs and is dominated by graminoid (i.e., grass and sedge) species. Ecologists recognize several types of plant communities with grassland structure that grade into each other along a soil moisture continuum from dry (e.g., sand barrens, dry prairie) to wet (e.g., sedge meadow, fen) conditions. Prairie is a more specific term used to describe grasslands dominated by grasses rather than sedges, and occurring near the middle of the soil moisture spectrum. Prairies occur where soils are neither typically dry (as in sand barren grasslands) nor permanently wet (as in sedge meadows). Curtis (1955; 1959) quantitatively arranged plant species abundance and composition along a gradient of soil moisture, and divided Wisconsin’s prairies into five types: wet, wet‐mesic, mesic, dry‐mesic, and dry. Each of these types grade imperceptibly into one another, and it can be difficult to differentiate among them based upon superficial characteristics such as plant species composition alone. Examples of each of these five prairie types can be seen at the Preserve. The vegetation structure of prairie is maintained by periodic wildfire regimes, which serve as a major controlling variable for this community type (Hobbs and Suding 2009). In the absence of fire, prairie vegetation is eventually replaced by fire‐intolerant shrubs and trees.

 

Burn pic (Sean)

Prescribed fire serves as an effective restoration tool to fight invasive and stimulate fire-adapted species.

Prior to Euro‐American settlement, prairie covered approximately 2.1 million acres of Wisconsin (Curtis 1959). The Wisconsin Department of Natural  Resources has estimated that only 13,000 acres of prairie remain in remnant condition in Wisconsin (Henderson and Sample 1995), a mere 0.6% of the original acreage. Conversion of prairie to agricultural production, rural land speculation and development, suppression of natural wildfire regimes (leading to invasion by shrubs and trees and successional advancement to alternative stable states), overgrazing, and displacement of native prairie vegetation by invasive species  have all contributed to the loss of acreage of original prairie. The Department further estimated that between 15 and 20 percent of the state’s original grassland flora and fauna are either considered rare or in decline (Henderson and Sample 1995). Most of the remaining remnant prairies are either of the wet or dry type, with many acres of remnant wet prairie impacted negatively by Phalaris dominance. Prior to Euro‐American settlement, mesic prairie was the dominant prairie type, covering more than one million acres. Today, less than 150 acres of remnant mesic prairie remains and much of this acreage is confined to small (less than five‐acre) isolated segments. Leach and Givnish (1996) quantified rates of species loss in 54 Wisconsin prairie remnants, and reported that unmanaged isolated Wisconsin prairie remnants were experiencing species losses between 0.5 and 3 species every year, an alarming loss of biodiversity and ecotypic identities. These authors also estimated that between eight and sixty percent of plant species were lost from isolated prairie remnants during a 32 to 52‐year time period. However, as Cochrane and Iltis (2000) point out, the prairie remnants used in their data set were unburned remnants and management regimes (or lack thereof) may have influenced their findings. Nevertheless, mathematical models of population dynamics predict that the only stable equilibrium point for an isolated population is local extinction (Kot 2001).

Blazing star (Liatris) and rattlesnake master (Eryngium yuccifolium)

Needless to say, prairie conservation is a top priority for Southwestern Wisconsin land managers. The Preserve is a reservoir of Wisconsin’s prairie heritage, with 43.5 acres of high‐quality remnant and 99.0 acres of high‐quality restored prairies. Remnants are of particular conservation value since they harbor residual species from the original prairies. Since 1987, the Swamplovers Foundation, Inc. has taken an active role in the preservation, rehabilitation, and maintenance of these imperiled communities.

The 30‐acre dry/dry‐mesic prairie remnant located at the southern point of the west ridge (management unit 1) supports more than 165 native plant species, one‐third of which have a coefficient of conservatism of seven or higher, meaning that these species are habitat specialists that typically only occur within high‐quality, well‐managed prairie remnants. Five species, cliff brake (Palleae glabella subsp. glabella), hoary puccoon (Lithospermum canescens), Leiberg’s panic grass (Panicum leibergii), prairie dropseed (Sporobolous heterolepis), and downy yellow painted cup (Castilleja sessiliflora), have a coefficient of conservatism of 10; four species, tuberous Indian plantain (Arnoglossum [Cacalia] plantagineum), clustered poppy mallow (Callirhoe triangulata), marbleseed (Onosmodium molle), and prairie turnip (Pediomelum esculentum), are considered species of Special Concern in Wisconsin, and an additional four species, giant yellow hyssop (Agastache nepetoides), pale purple coneflower (Echinacea pallida), cream gentian (Gentiana alba), and wild quinine (Parthenium integrifolium), are listed in Wisconsin as Threatened. Two species that are indigenous to the Preserve, E. pallida and C. triangulata, occur beyond the range of what was thought to be their historical distributions. The population of E. pallida at the preserve is the northernmost indigenous population of this species in Wisconsin. Similarly, C. triangulata was not known to occur in Dane county prior to its discovery in this remnant in 2008 by Gerald Goth and Craig Annen. Permanent records of the locations, presence, and abundance (when known) of all species of conservation concern at the Preserve have been submitted to Wisconsin’s Natural Heritage Inventory (NHI). This remnant further provides habitat for two species of Protected Wild Animal, the blue racer (Coluber constrictor) and bullsnake (Pituophis catenifer sayi), a population of prairie vole (Microtus ochrogaster, Special Concern), eight species of grassland birds considered Special Concern in Wisconsin, and a species of wasp (Stephanidae: Megischus sp.) that was previously undocumented in Wisconsin. Floristic quality (Swink and Wilhelm 1994; Wisconsin values from WDNR 2003) of this remnant was estimated at 65.6 in 2009. To put this figure into perspective, Swink and Wilhelm (1994) considered a vegetation assemblage with a FQI (Floristic Quality Index) value ≥ 45 to be indicative of a remnant community with high natural area (and conservation) potential. Intensive management of this remnant, funded by the Wisconsin DNR’s Landowner Incentives Program (LIP) and the Swamplovers Foundation, Inc., led to a 16.3% increase in floristic quality during the 2007‐2009 sampling period.

The eight‐acre mesic prairie remnant, located at the base of the eastern slope of the eastern ridge (management unit 7), has a species richness of 46, with a mean coefficient of conservatism of 4.7 and FQI value of 32 (a value of 35 indicates that there is sufficient floristic quality present for a community to have moderate natural area potential (Swink and Wilhelm 1994). An additional small mesic prairie remnant occurs along the Burlington‐Northern Railroad immediately south of the Preserve, and the

presence of two mesic prairie remnants in close proximity further increases the conservation potential of unit 7. Nine species in this unit are modal to mesic prairie, meaning that they were sampled in highest frequency in this prairie type by Curtis (1959). This unit also supports a small population of the Special Concern species tuberous Indian plantain, scattered individuals of the Threatened pale purple coneflower, and a large population of the cream gentian.

cream gentian (Gentiana alba)

Less is known about the diversity and composition of the remnant prairies of units 12 and 22, which were initially discovered in 2008. Preliminary management actions (tree and brush clearing and prescribed burns) were initiated in these units in 2008.

The 25‐acre restored prairie located at the north end of the eastern valley (management unit 15) was planted with a mixture of 50 wet‐mesic species in 1998. The seed source of some species was local remnants; others were purchased from local nurseries. Prior to planting and enrollment in the CRP program, all of unit 15 was in agricultural production (usually corn but  occasionally soybeans) for several decades. The site was prepared for planting by repeated iterations of disking and glyphosate application (two to three times per growing season) for three growing seasons. Twenty acres of unit 15 was planted  in the autumn of 1998 by culimulching to a depth of four inches followed by planting with a Bruillon Seed Drill. The restoration was mowed annually during its initial establishment and subsequent maintenance has consisted of biennial prescribed burns and control of thistle outbreaks (Cirsium arvense, C. vulgare, and Carduus natans) with the herbicide clopyralid. An additional five acres of this section was planted with 45 wet‐mesic species in the autumn of 2003 according  to the same procedure, except that the seed was hand broadcast onto the soil surface rather than drilled into the soil. Eleven years after planting, this wet‐mesic prairie restoration is a reasonable facsimile of a remnant prairie. In 2008, FWS technicians who were participating in a workshop on the property initially thought this planting was indeed a remnant rather than a restoration. Unit 15 supports a population of the Wisconsin‐Endangered Silphium borer moth (Papaipena silphii), and also populations of pink streak moth (Faronta rubiperennis), ottoe skipper (Hesperia ottoe), and Leonard’s skipper (Hesperia leonardus), which are listed as Special Concern species in Wisconsin. This  restored prairie further supports three additional unique moth species, Thelma’s Agronopterix (Agronopterix thelmae), which was never documented in Wisconsin prior to being collected at the Preserve in 2008, Franclemont’s Pinion (Lithophceue franclemonti), which was first described as a new species in 1998 (but not at the Preserve) and is rarely sampled in surveys, and the Brick Red Borer Moth (Papaipema marginidens), of which there is only one other known record from Wisconsin. In 2009, the hickory hairstreak butterfly (Satyrium  caryaevorum), another uncommonly collected species, was sampled near unit 15. In 2010, this species was observed by four different individuals (Karl and Dorothy Legler, Ann Thering, and Kyle Johnson) on different sampling dates, indicating  that it occurs in abundance at the Preserve.

Pale Purple Coneflower (Echinacea pallida), WI threatened species

The 60‐acre restored prairie of the west valley (management unit 20) was planted with 80 wet and wet‐mesic prairie species in autumn 1997. Again, seed sources were a mixture of seed collected from local remnants and nursery stock.  Prior to planting and enrollment in the CRP program, this planting was also in agricultural production for several decades. This unit was prepared for planting with the same methods used for unit 15 in the east valley. Unfortunately, the aggressive perennial reed canarygrass (Phalaris arundinacea) soon invaded this planting and by 2006 was the dominant species at ca. 80% cover. In 2007, a reed canarygrass suppression program was initiated to return this planting back to its full ecological potential. Subsequent maintenance has consisted of late‐season annual prescribed burns (conducted from late April to early May, in accordance with reed canarygrass management) followed by broadcast applications of grass‐ selective herbicides. This management regime has been moderately successful, although high water levels during the 2008 and 2009 growing seasons precluded application of reed canarygrass treatment prescriptions over the entire 60 acres of this unit. In 2008, following a single growing season of active reed canarygrass management, Craig Annen (as part of a reed canarygrass research project funded in part by the Swamplovers Foundation) documented the presence of 79 native species in management unit 20. Interestingly, four non‐planted species of conservation value were also documented in unit 20 including turk’s cap lily (Lilium superbum), glade mallow (Napaea dioica, a species of Special Concern), sweet Indian plantain (Special Concern), and wild quinine (Threatened). In addition, eastern prairie fringed orchids (Platanthera leucophaea, an Endangered species) were transplanted into this management unit in 2007 and 2008, one of which survived the transplant. This orchid bloomed in 2008 and 2009. The 79 species of unit 20 had a mean coefficient of conservatism of 5.36 and the FQI value of 47.6 (Appendix A‐5). Species density ranged from 5.1 – 6.1 species per 0.125 m2 (n = 32 quadrat samples). In September 2008, mean aboveground biomass was estimated at 467.8 g/m2. If we assume that two‐thirds as much biomass occurs in the belowground fraction, as has been posited by several authors, multiplying aboveground standing crop by a factor of 1.67 gives us an approximate estimate of 781.3 g/m2 for belowground biomass. Summing the estimates for above‐ and belowground biomass and multiplying by the acreage of this management unit, we arrive at an estimate of the amount of carbon that has been stored in this restored wet prairie since planting, roughly 288,220 kg (5,056 kg/acre).

The eight‐acre wet prairie restoration of Unit 31 was planted in 1999 with a mixture of species collected from management unit 20. On 19 November 2008, a two‐acre buffer between units 13 and 14 (designated management unit 31) was planted with a mixture of 57 species at a rate of 5.3 lbs/acre and a graminoid/forb ratio of 1:3. The site was prepared by two rounds of late spring treatment with the broad‐leaf herbicide dicamba to eliminate invasive weeds and create a smooth brome monotype. This stand was burned and lightly disked in early November 2008 to expose the soil surface for planting without stirring up any of the residual weed seed bank that may have still been present. Seed was hand‐broadcast and mixed with vermiculite pellets to ensure uniform coverage and was lightly cultipacked soon after planting.

Summary of Ecological Management Goals for Prairie and Grassland Surrogate Communitie

  • Restore remnant prairie communities to their presettlement condition.
  • Establish mesic prairie vegetation in buffer zones between adjacent community types at the Preserve to facilitate a wetland‐to‐upland continuum of habitat gradation and increase the effective acreage of mesic prairie in Wisconsin.
  • Reintroduce periodic wildfire regimes to grassland communities.
  • Reduce or eliminate populations of high‐impact invasive species.
  • Catalog species richness across all trophic levels and enhance habitat quality to maximize species richness and diversity.
  • Establish and maintain habitat structural elements to benefit wildlife.