TITLE:
Drought and Grazing Effects on Oklahoma Phlox (Polemoniaceae, Phlox oklahomensis)
AUTHORS:
Tim L. Springer, Stacey A. Gunter, Ronald J. Tyrl, Paul F. Nighswonger
KEYWORDS:
Phlox oklahomensis; Drought; Grazing
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.4 No.6A,
June
19,
2013
ABSTRACT: Oklahoma phlox
(Phlox oklahomensis Wherry) is endemic to Butler,
Chautauqua, Comanche, Cowley, and Elk Counties of Kansas and Woods and Woodward
Counties of Oklahoma. The species comprises populations of a few
scattered individuals to several hundred in mixed-grass prairie sites in
Oklahoma where cow-calf production is the common agricultural enterprise. It
has successfully withstood periods of short-term drought (1 to 4 years) under
light to moderate continuous stocking rates (41 to 52 animal unit days per
hectare). Under heavy continuous stocking rates and/or prolonged drought,
populations of P. oklahomensis tend
to decrease in size and number and may disappear in some localities. Prolonged
heavy stocking rates and drought will disrupt the reproductive cycle, severely
limiting seed production and recruitment of
new individuals to populations. During drought periods, livestock managers
should use lighter stocking rates or deferred grazing to ensure rapid recovery
of all prairie plants, including P.
oklahomensis, once the drought ends. This recommendation would likely
sustain prairie sites during long-term (longer than 10 years) droughts as well.