Abstract Detail

Ecology

Holmes, Marion [1], Whitacre, James [2], Bennion, Leland [3], Poteet, Jessica [4], Kuebbing, Sara [5].

Forest plants amid overlapping landscape mosaics: land-use history and soils together shape native shrub communities in second-growth forests.

Forest communities are shaped by multiple layers of pattern including abiotic gradients and disturbance history. Land use is a widespread form of disturbance in the eastern deciduous forest that includes a variety of practices with different impacts on soils and native vegetation. Land-use history shapes the structure, composition, and diversity of modern forest communities for decades, or even centuries, after abandonment, but the specific differences between legacies of mining, agriculture, and logging often remain unanalyzed. Similarly, while many previous studies of land-use legacies address tree communities, non-native species, and the physical environment, little research has addressed shrub communities specifically. We aim to better understand how native shrub communities reflect contrasting land-use histories of mining, agriculture, and logging. We test the hypothesis that shrub composition and diversity are shaped by the differing impacts of agriculture, mining, and logging. Alternatively, shrub communities may instead conform to environmental gradients. We sampled the native shrub community in second-growth forest sites with histories of mining (n=4), agriculture (n=4), logging (n=4), and older second-growth (n=14) with no recent history of land use at Powdermill Nature Reserve in Westmoreland County, PA, USA. Community composition, species richness, and distributions of three common shrub species were analyzed to test for differences between land-use classes and the influence of environmental variables. Shrub community composition differed significantly between land-use history groups, but was most strongly linked to soil pH. Formerly mined and agricultural sites were characterized by generalist species like Lindera benzoin. Logged and old forest composition sorted according to soil pH, with more acidic sites hosting ericaceous species like Gaultheria procumbens and Rhododendron periclymenoides while Sambucus canadensis and Viburnum prunifolium were associated with higher-pH areas. Drivers of common species distributions varied: Hamammelis virginiana was significantly more frequent in less-disturbed logged and old forest sites. Lindera benzoin did not show any significant relationship with land use or site gradients, and Vaccinium pallidum presence was predicted by soil pH. Shrub communities, as well as distributions of individual species, are influenced by the interaction of anthropogenic disturbance and abiotic gradients.

1 - 232 Copeland Ave, Braddock, PA, 15104, United States
2 - Powdermill Nature Reserve
3 - Kent State University
4 - University of Pittsburgh
5 - Yale University, Applied Science Synthesis Program, New Haven, CT, 06511, USA

Keywords:
land-use history
shrubs
hamammelis virginiana
lindera benzoin
vaccinium pallidum
disturbance ecology
community assembly.

Presentation Type: Oral Paper
Number: EC03005
Abstract ID:555
Candidate for Awards:None