Tree uprooting: review of impacts on forest ecology

Abstract

This paper reviews the ecological effects of tree uprooting. In many forests, disturbance by uprooting is the primary means of maintaining species richness and diversity. Treefall may be due to exogenous factors or it may be endogenously created, although the former predominate. The canopy gap formed by downed trees is often vital to community vegetation dynamics and successional pathways, by providing high light niches (gaps) for pioneer species, by encouraging release of suppressed, shade-tolerant saplings, and through recruitment of new individuals. Nutrient cycling may be affected by uprooting as subsoil materials are brought to the surface, via additions of woody debris to the forest floor, through exposure of bare mineral soil, and by changes in throughfall chemistry. The influence of the resultant pit/mound microtopography on understorey herb distribution is largely due to microclimatic and microtopographic variation. Tree seedling distribution, however, is related to microtopography primarily through differences in soil morphology, nutrition, and moisture content of mound and pit sites.

Disturbances can control fine-scale pedodiversity in old-growth forests: is the soil evolution theory disturbed as well?

“…The coarse-grained material of the mound represents specific material (e.g. Schaetzl et al, 1989a), in which soil horizons are newly formed; similar material is uncovered in the pit as well. The pit-mound microtopography is gradually levelled over time (with a maximum pit-mound longevity up to circa 1700 years, Šamonil et al 2013b), but the unique soil features persist for a longer period (e.g.…”

Responses of Ground-Dwelling Invertebrates to Gap Formation and Accumulation of Woody Debris from Invasive Species, Wind, and Salvage Logging

“…Koivula and Spence [123] reported increased activity-abundance and species richness with increasing salvage logging intensity (low: 23-30% timber removed, moderate: Severe wind storms generally fell a high proportion of canopy trees forming large, patchy gaps, although some trees lose only branches and remain standing [96]. Tipped trees form pits and mounds that mix organic and mineral layers, expose rocks and roots, and create distinct microsites that differ from neighboring undisturbed soil [97][98][99][100][101]. Trees fall nearly simultaneously and often in the same direction, resulting in accumulation of CWD of different species, types, and sizes [36,96].…”

Windthrows increase soil carbon stocks in a central Amazon forest

“…In the tropics, winds break and uproot trees causing strong soil disturbances (e.g., increasing leaves and wood debris and changing morphology and nutrient availability; Schaetzl et al, 1989;Lugo, 2008). Treefall gaps can also change microclimate conditions such as light intensity and create a variety of microsites, which can be separated into canopy, trunk, and root/uprooted sites (Putz, 1983).…”

“…Treefall gaps can also change microclimate conditions such as light intensity and create a variety of microsites, which can be separated into canopy, trunk, and root/uprooted sites (Putz, 1983). These microsites have important features that drive soil and vegetation recovery after disturbance (Putz, 1983;Schaetzl et al, 1989;Vitousek and Denslow, 1986). They can differ in microbial activity (Batjes, 1996) and enhance the colonization of fast-growing species that help in the assimilation of nutrients and soil carbon, which in turn can contribute to quickly restore the forest canopy through succession (Putz, 1983).…”

“…They can differ in microbial activity (Batjes, 1996) and enhance the colonization of fast-growing species that help in the assimilation of nutrients and soil carbon, which in turn can contribute to quickly restore the forest canopy through succession (Putz, 1983). This rapid recycling of nutrients potentially enhances the resilience of tropical forests to natural disturbances (Schaetzl et al, 1989;Ostertag et al, 2003;Lugo, 2008). However, how complex and hyperdiverse tropical forests such as the Amazon will respond in a scenario of higher frequency of extreme weather events (Coumou and Rahmstorf, 2012;Cai et al, 2014) is still not clear.…”