The influence of competition and soil on the distribution of two potentially dominant bunchgrass species: Wiregrass (Aristida stricta) and little bluestem (Schizachyrium scoparium)
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Dr. Paul Gagnon
Presentation Format
Event
Abstract/Description
The Longleaf pine ecosystem (LLP), which once covered more than 25 million hectares along the US gulf coastal plain, has only 5% of its original extent remaining, making it among the most threatened ecosystems in North America. LLP is characterized by an open overstory of longleaf pines (Pinus palustris) and an extremely diverse, bunchgrass-dominated understory, with up to 40 species/m2. These high diversity understory communities are adapted to and maintained by periodic fires every 1-4 years. Fires prevent hardwood encroachment and maintain savanna conditions. Bunchgrasses serve as a matrix species in LLP savannas by providing the fires with ample, continuous fuels that enable fires to spread throughout. Wiregrass (Aristida stricta) and little bluestem (Schizachyrium scoparium) are two commonly dominant bunchgrasses in LLP savanna. Wiregrass tends to dominate in the eastern coastal plain while little bluestem is typically dominant in the western gulf coastal plain. Unusual disjuncture’s in the ranges of wiregrass and little bluestem have long puzzled scientists and make for long, sharp boundaries at which bluestem dominated areas abut areas dominated by wiregrass. The affect of these two species on one another is poorly understood and important to LLP restoration, which is why I ask: How does bunchgrass dominance at a LLP site effect the growth of transplanted wiregrass and little bluestem individuals? Embedded in this question is another about the extent to which the soil of a particular site affects the growth of native and off-site bunchgrasses. The study site is Eglin Air force base in northwest Florida and is positioned along the transition line of A. stricta and S. scoparium, making Eglin AFB a superb location to examine how these two species of bunchgrasses are affecting each other. I designed a reciprocal transplant study in which individuals of both species were planted in sites dominated by either wiregrass or little bluestem. The results of this experiment, now being analyzed, should help us better understand how these species interact and the extent to which the edaphic environment influences their success.
Location
Barkley Room, Curris Center
Start Date
April 2016
End Date
April 2016
The influence of competition and soil on the distribution of two potentially dominant bunchgrass species: Wiregrass (Aristida stricta) and little bluestem (Schizachyrium scoparium)
Barkley Room, Curris Center
The Longleaf pine ecosystem (LLP), which once covered more than 25 million hectares along the US gulf coastal plain, has only 5% of its original extent remaining, making it among the most threatened ecosystems in North America. LLP is characterized by an open overstory of longleaf pines (Pinus palustris) and an extremely diverse, bunchgrass-dominated understory, with up to 40 species/m2. These high diversity understory communities are adapted to and maintained by periodic fires every 1-4 years. Fires prevent hardwood encroachment and maintain savanna conditions. Bunchgrasses serve as a matrix species in LLP savannas by providing the fires with ample, continuous fuels that enable fires to spread throughout. Wiregrass (Aristida stricta) and little bluestem (Schizachyrium scoparium) are two commonly dominant bunchgrasses in LLP savanna. Wiregrass tends to dominate in the eastern coastal plain while little bluestem is typically dominant in the western gulf coastal plain. Unusual disjuncture’s in the ranges of wiregrass and little bluestem have long puzzled scientists and make for long, sharp boundaries at which bluestem dominated areas abut areas dominated by wiregrass. The affect of these two species on one another is poorly understood and important to LLP restoration, which is why I ask: How does bunchgrass dominance at a LLP site effect the growth of transplanted wiregrass and little bluestem individuals? Embedded in this question is another about the extent to which the soil of a particular site affects the growth of native and off-site bunchgrasses. The study site is Eglin Air force base in northwest Florida and is positioned along the transition line of A. stricta and S. scoparium, making Eglin AFB a superb location to examine how these two species of bunchgrasses are affecting each other. I designed a reciprocal transplant study in which individuals of both species were planted in sites dominated by either wiregrass or little bluestem. The results of this experiment, now being analyzed, should help us better understand how these species interact and the extent to which the edaphic environment influences their success.