Abstract Detail

Bryological and Lichenological Section/ABLS

Scharnagl, Klara [1].

Effects of Microclimate and Disturbance on Morphological Traits of Lichen Communities.

Lichen communities are known to shift in response to environmental disturbance, including air pollution, habitat destruction, and introduction of invasive species. Lichen communities also respond to natural disturbances such as snowmelt, rockslides, and forest succession. Most studies of lichen community shifts have thus far focused upon the species turnover in lichen communities, without focusing much upon the change in overall lichen morphology or chemistry in response to environmental disturbance. In Big Cypress National Preserve, twenty cypress domes were surveyed for lichen diversity and community turnover in response to microclimate and disturbance. Cypress domes are unique features in Big Cypress and Everglades National Park in south Florida; due to slight depressions in the topography, water is present even during the dry season, enabling trees to grow taller, while trees further from the depression are stunted in their growth during the dry season, leading to a dome-shaped cluster of similar-aged cypress [Taxodium distichum] trees. This dome shape further creates a microclimate of partial sun and moisture at the center of the dome, and full sun and dryness at the edge of the dome, leading potentially to uniquely different lichen communities on the cypress tree trunks. A gravel road, called 11-Mile Road, runs through the southeastern portion of the preserve; many large trucks involved in a mining operation use this road, causing airborne dust as well as exhaust. It is assumed that lichens on trees closer to the road will be impacted by this disturbance, whereas lichens on trees further from the road will escape this disturbance pressure. As a result, the community composition of lichens in domes closer to the road should be different from the community composition of lichens in domes further from the road. This study investigates the morphological and chemical diversity of lichen communities as they respond to impacts from disturbance [road] and microclimate [position in cypress dome]. Twenty domes were sampled for lichens. Domes were chosen at random at varying distances from the road. A transect was run from the edge of the dome closest to the road to the center of the dome. Every tree along the transect was sampled for lichens at 1.5m height on the N, S, E and W faces of the tree. Lichen communities do differ from the edge to the center of each dome, and between domes, implying a significant influence of both microclimate and disturbance on the community composition of lichens.

1 - Michigan State University, Plant Biology, 612 Wilson Rd, East Lansing, MI, 48824, USA

Keywords:
lichen
Morphology
microclimate
disturbance
community.

Presentation Type: Oral Paper:Papers for Sections
Session: 2
Location: Firs North/Boise Centre
Date: Monday, July 28th, 2014
Time: 11:00 AM
Number: 2012
Abstract ID:117
Candidate for Awards:A. J. Sharp Award