Effects of prescribed fall burning on a wetland plant community, with implications for management of plants and herbivores
An important contemporary challenge for adaptive resource management is assessing both the direct and indirect effects of management activities by designing appropriate monitoring programs and sound analysis methods. Here we evaluate the effects of prescribed fall burning on a wetland plant community that is managed primarily for spring-migrating geese. During late fall in 2 consecutive years, we burned vegetation in 4 replicate blocks (2.3 ha each) that traversed a natural moisture and associated vegetation gradient. We used ordination, gradient analysis, and contingency table analysis to evaluate how annual changes in relative abundance of plants were affected by burning as well as other important ecological factors. Burning increased species diversity of plants, especially in the 2 wetter vegetation zones, but had no effect on species richness or on the proportion of native plant species. Wetland plant species responded to prescribed burning independently, and their response often differed by vegetation zone and with annual variation in flooding. Burning enhanced the abundance of native foxtail barley (Hordeum jubatum) and reduced the abundance of introduced swamp timothy (Crypsis shoenoides). Saltgrass (Distichlis spicata), a native plant species, was usually less abundant following burning, although the level of response was different for each of the 3 vegetation zones. Two other introduced plant species, quackgrass (Elytrigia repens) and reed canarygrass (Phalaris arundinaceae), were less abundant after fall burning, especially when spring flooding was more extensive. Wild geese using the experimental blocks for feeding clearly preferred burned sites, suggesting that fall burning can enhance wetland use by geese during spring. Given that simple manipulations such as burning and flooding of a wetland system may often produce complex results, we suggest that on-going management schemes be regularly evaluated with field experiments such as those conducted in this study.
McWilliams, Scott R.; Sloat, Todd; Toft, Catherine A.; and Hatch, Daphne
"Effects of prescribed fall burning on a wetland plant community, with implications for management of plants and herbivores,"
Western North American Naturalist: Vol. 67:
2, Article 13.
Available at: https://scholarsarchive.byu.edu/wnan/vol67/iss2/13