Effects of habitat and growing season fires on resprouting of shrubs in longleaf pine savannas

Abstract

The effects of habitat and timing of growing season fires on resprouting of shrubs were studied in second-growth longleaf pine savannas of the west Gulf coastal plain in the southeastern United States. Within the headwaters of three different drainages of the Calcasieu River in the Kisatchie National Forest in western Louisiana, replicated permanent transects were established that extended from xeric upland longleafpine savannas into downslope hydric seepage savannas. All shrubs were mapped and tagged, and numbers of stems were counted prior to any fires. Replicated prescribed fires were set early (June) and late (Augus0 during the 1990 growing season; maximum fire temperatures were measured within both upland and seepage habitats within each transect. Shrubs were relocated; stems were recensused two and twelve months after the fires. At least some shrubs of all species resprouted from underground organs; none regenerated solely from seed banks in the soil. There was no reduction in total numbers of stems one year after fires compared to before fires, either in the upland or in seepage savannas. In addition, there was no reduction in total numbers of stems one year after early or late growing season fires. Fire-related mortality was restricted to small shrubs (< 18 stems) and was not associated with high fire temperatures. The rate of resprouting varied among species and between habitats. Resprouting occurred more rapidly in seepage than upland savannas, but more resprouts were produced in upland than seepage savannas one year after fires. In contrast to other upland species, Vaccinium arboreum and V eUiottii delayed resprouting more than two months following fire. Stems of Rhus copallina and Pyrus arbutifolia, species with long rhizomes, increased more after fires in June than fires in August. We suggest that growing season fires may block further recruitment of shrubs into longleaf pine savannas, but reduction in numbers of large shrubs may require additional management.

Accurate Quantification of Seasonal Rainfall and Associated Climate–Wildfire Relationships

“…4). Such bimodal patterns are unusual in the region, and are normally found .300 km to the north where the jet stream has a more consistent influence (Chen and Gerber 1990;Olson and Platt 1995;Huffman 2005). Conversely, La Niñ a episodes produced high pressure over the region, steering the jet stream north and resulting in less frequent and weaker storm fronts.…”

Tree Species Composition, Structure, and Aboveground Wood Biomass of a Riparian Forest of the Lower Miranda River, Southern Pantanal, Brazil

“…Resprouting increases root and stem surfaces in these species and thus facilitates aeration during flooding (Lüttge 1997). In addition, it allows for the persistence of many shrubs and trees after catastrophic events such as fire (Matlack et al 1993;Olson and Platt 1995;Cirne and Scarano 2001). It is thus possible that species originating from the adjacent Cerrado, and with high resprouting ability, have an important pre-adaptation that makes them competitive when establishing in seasonal flooded areas of the Pantanal.…”

Preparing Florida Pasture for Grassland Restoration: Seedling Establishment after Herbiciding and Tilling

“…Early growing-season fires can also depress woody shrubs and trees since they introduce a second stress at the time of year that these species are already under stress and have low carbohydrate reserves after green-up (Platt et al 1990). Consistent application of annual or biennial growing-season fires, in other southeastern United States seepage communities can lead to a decline of shrub recruitment and also a decrease in shrub abundance (Drewa andPlatt 1997, Olson andPlatt 1995).…”