Vegetative Response to Clearcutting and Chopping in a North Florida Flatwoods Forest

Abstract

Selected naturally regenerated flatwoods forests were clearcut and chopped in preparing a large, long-term study of the effects of several multiple-use management practices on forest vegetation and wildlife. Early effects of clearcutting and chopping on understory vegetation are reported here. Clearcutting and chopping reduced woody understory coverage from 66 to 18% of surface area. Common gallberry and saw-palmetto were reduced by 75 and 8!9& respectively. Herbaceous species frequency was htcreased: Panicurns by over 3,000%; bluestems by 173%; grasslies by over 2,000%; and forbs by 308%. Graphical analyses show an increase in herbaceous species diversity as a result of mechanical site disturbance. Comparing these graphs with those reported on the effects of prescribed burning suggests that the collective vegetative response to mechanical site disturbance is qualitatively similar to the response to fire. Quantitatively the response to mechanical disturbance is more pronounced. Successful production of wood, cattle, and wildlife in the southern pinelands depends on methods of managing both overstory and understory simultaneously to increase multiple product yields while avoiding environmental and ecological degradation. In 1976 we began a large study to examine various effects of an array of forest management practices on wildlife and wildlife habitat, and on herbage production. Portions of the study area were only burned. An early assessment of the effects fire produced on the understory vegetation was reported by Moore, et al. (1982). Other portions of the study area were clearcut, chopped, and replanted to pines. Reported here is an early assessment of the effects of mechanical site disturbance on understory vegetation, and a comparison of these effects with the earlier reported effects of prescribed fire. The comparison is made to show that mechanical disturbance in natural flatwoods forests has effects similar to prescribed fire-which is widely regarded as a useful tool of range and wildlife managers. Study Area and Methods The 73ha experimental area is on the University of Florida's Austin Cary Memorial Forest near Gainesville, Alachua County, Florida. When this study began the experimental area was occupied by a naturally regenerated 50-year old flatwoods forest averaging 20.7 m2 of basal area per ha and 70.8% crown cover. The overwhelming majority of overstory trees were either slash or longleaf pine. There were a few water oaks and occasionally some other hardwood species, especially in wetter spaces. A brief history of the experimental area and a description of the soils on the site are given by Moore et al. (1982). The entire experimental area was prescribed burned during the winter of 1975-76 with no perceptible effect on the overstory.

Expansion and population structure of transplanted Aristida beyrichiana (wiregrass) tussocks: results of a 37‐year study

“…Rodriguez 2011), high light levels (Means 1997), minimally required edaphic and hydrological conditions (Carr et al 2010), and absence of severe soil disturbance (Moore et al 1982), our study likely would have shown a decrease in the originally planted population under other conditions. Understanding the specific management conditions required to increase populations of plants with particular life historic characteristics should be a continued focus of restoration research.…”

“…Under the conditions studied, wiregrass showed the fundamental characteristics of a species predicted to be successful in restoration efforts following low‐density planting, including strong competitive ability, capacity to colonize gaps in vegetation, ability to undergo vegetative reproduction, and a relatively wide edaphic niche as suggested by the differences between source sites (Pywell et al 2003). However, whereas wiregrass shows the capacity to gradually become dominant under the appropriate fire frequency and season (Mulligan & Kirkman 2002; Rodriguez 2011), high light levels (Means 1997), minimally required edaphic and hydrological conditions (Carr et al 2010), and absence of severe soil disturbance (Moore et al 1982), our study likely would have shown a decrease in the originally planted population under other conditions. Understanding the specific management conditions required to increase populations of plants with particular life historic characteristics should be a continued focus of restoration research.…”

“…Where present it is often dominant and promotes frequent fires on which the ecosystem depends (Outcalt et al 1999; Fill et al 2016), provides cover for wildlife (Meanley 1988; Martin et al 2009), and plays an important role in soil carbon sequestration (Saterson & Vitousek 1984; West & Donovan 2004) and maintenance of natural hydrological cycles (Brantley et al 2018). Wiregrass has been greatly reduced from its original extent, in part because it is particularly susceptible to mechanical soil disturbance associated with agriculture, forestry, and wildlife management (Moore et al 1982; Watts & Tanner 2003) and is slow to recolonize areas where it has been eliminated (Kirkman et al 2004; Ostertag & Robertson 2007). It follows that restoration of wiregrass is a high conservation priority for reestablishing wildlife habitat, maintaining natural ecosystem function, and providing the unique aesthetic associated with native longleaf pine ecosystems.…”

Species Diversity and Diversity Profiles: Concept, Measurement, and Application to Timber and Range Management

“…Rare species influence the perpetuation of some desirable community components more than do abundant species and are frequently suggested as being required in order to maintain biological diversity. Although these diversity assessments are indifferent to plant names, graphical methods for examining individual species responses to treatment are available (Moore et al 1982a(Moore et al , 1982b.…”