Changes in Soil Properties Following 55 Years of Secondary Forest Succession at Fort Benning, Georgia, U.S.A.

Abstract

We present results on changes in soil properties following land use change over an approximately 55-year period at Fort Benning, Georgia, U.S.A. Soil cores were taken at 129 locations that were categorized as reforested (field/ bare ground in 1944 and forest in 1999), disturbed (field/ bare ground in 1944 and 1999), or reference forests (forest in 1944 and 1999). Soil disturbance included historic agriculture (pre-1944) and military training (post-1944). Density in mineral soils exhibited a historic land use legacy effect (reference < reforested < disturbed). Rates of change in bulk density decreased with depth and estimated total times to reach reference forest levels ranged from 83 (0-10 cm) to 165 (30-40 cm) years. A land use legacy effect on C stock was apparent in the O-horizon and in 30-to 40-cm soil increment (reference > reforested > disturbed). Soil C stock in all other increments and in particulate organic matter was affected by disturbance; however, no legacy was apparent (reference = reforested > disturbed). For the entire soil profile (O-horizon to 40 cm), rate of C accrual was 28 g m 22 yr 21 (1.5%/yr). Nitrogen stocks were affected by disturbance in the O-horizon and 0-to 10-cm increment; however, no legacy effect was detected (reference = reforested > disturbed). Nitrogen accumulated at 0.56 g m 22 yr 21 (0.6%/yr) for the entire soil profile. At Fort Benning, soil C and N stocks of reforested stands were similar to those of reference forested stands after approximately 55 years. However, soil bulk density was greater on reforested stands than reference forest stands at 55 years and may require an additional century to reach reference levels.

Land use history alters the relationship between native and exotic plants: the rich don’t always get richer

“…However, our sites were broadly dispersed over a landscape comprised of similar topographies, they possess some similar soil characteristics, including soil type (fine loamy ultisols), grain size composition and mineralogy (Pierce 1974), and our results are consistent with numerous studies documenting higher soil compaction on previously cultivated versus uncultivated land (Compton et al 1998;Lemenih et al 2005;Maloney et al 2008), suggesting that the observed differences are the result of previous land use.…”

“…Following a peak of agriculture in the early 1900s, increasing farm consolidation led to the widespread abandonment of small farmlands across much of eastern North America (Flinn and Vellend 2005), and these postagricultural lands are often marked by distinctively different conditions than lands that have never been cultivated (Foster et al 2003). Soils on historically cultivated sites, for example, are often more compacted, have greater bulk density, lower organic content, altered pH, and less microbial biomass than comparable non-cultivated sites (Burke et al 1995;Compton and Boone 2000;Falkengren-Grerup et al 2006;Maloney et al 2008). The relationship between previous cultivation and soil nutrient availability is more variable and highly dependent on the type of agricultural regime followed (McLauchlan 2006), as well as the post-agricultural plant community Kulmatiski et al 2006).…”

Recovery of soil properties and functions in different rainforest restoration pathways

“…There is increasing evidence that deforestation not only alters above-ground vegetation, but also leads to significant changes in the physical and chemical characteristics and biochemical cycles of soil ecosystems (Vitousek et al, 1989;Piccolo et al, 1994;Erickson et al, 2001;Maloney et al, 2007). The fate of nitrogen in deforested landscapes is relatively well known: lower total nitrogen pools (Piccolo et al, 1994;Rasiah et al, 2004), decreased nitrate levels (Piccolo et al, 1994;Reiners et al, 1994;Neill et al, 1997b;Rasiah et al, 2004), and an altered N-mineralisation and nitrification capacity Montagnini and Buschbacher, 1989;Steudler et al, 1991;Reiners et al, 1994) have been reported.…”

Does soil variation between rainforest, pasture and different reforestation pathways affect the early growth of rainforest pioneer species?

“…Deforestation can significantly alter soil physical and chemical properties and biochemical cycles in rainforest landscapes, although different studies have reached varying conclusions about the extent to which reforestation re-establishes the full range of soil properties (Bashkin and Binkley, 1998;Rhoades et al, 2000;Rasiah et al, 2004;Silver et al, 2005;Zheng et al, 2005;Maloney et al, 2008;Paul et al, 2010). Nevertheless, there is a general consensus that reforestation can successfully restore many aspects of the nitrogen cycle, including nitrogen (N) stocks, nitrogen mineralisation, nitrate concentrations, and nitrification rates (Lamb, 1980;Robertson and Vitousek, 1981;Robertson, 1984;Vitousek et al, 1989;Rasiah et al, 2004;Scowcroft et al, 2004;Paul et al, 2010).…”