Abstract Detail

Bryological and Lichenological Section/ABLS

Howe, Natalie [1], Baumgarten, Joni [2], Dighton, John [3].

Influence of lichen mats on forest soils and vegetation patterns.

Lichens are known for their profound influence on soil processes in systems with few other producers, but our work investigates how lichens on soils change soil biological and chemical processes in a temperate forest ecosystem. We study Cladonia-dominated lichen mats of the NJ Pinelands because they represent high biomass in the forest floor, and because the sandy, acidic soils are low in organic matter and nutrients, so any lichen-induced effects on chemical cycling could be important for microbial growth, plant growth and soil animal food webs.
The first part of our study addressed how lichen mats influence belowground processes and asked whether the lichens in these mats altered soil nutrient cycling patterns and whether the lichens have top-down influence on soil micro-arthropod communities. To compare the influence of lichens with that of other ground covers, we constructed a transplant grid with different aboveground material (lichens, pine needles, oak leaves, and bare ground) on two sites in January 2013. We present data from these sites that were monitored seasonally for 2 years, and show analyses of trends in soil moisture, soil chemistry, soil microbial community activity and soil arthropod presence. We found that the influence of lichens on soils varies with soil and climate conditions; in dry soils, lichens contribute to moisture retention, and in soils with high inorganic phosphorus availability, lichens reduce phosphorus levels. Lichens also promoted higher densities of collembolans in the summer, which may be due to lichen influence on soil moisture as these organisms are more sensitive to desiccation than more waterproof cryptostigmatid mites.
Since lichens affect soil parameters, the second part of our study investigated the effects that lichens have on the interaction between an invasive plant, Teesdalia nudicaulis, and native plant communities in dry pine barrens soils. T. nudicaulis is non-native to the Pine Barrens, and related to Garlic mustard (Alliaria petiolata) which allelopathically decreases mycorrhizal colonization of other plants around it. If lichens are interfering with establishment of T. nudicaulis, areas with high lichen cover will be associated with low cover of T. nudicaulis and higher mycorrhizal colonization in native plants.
This work contributes to our understanding of how lichens change forest soils and therefore why the maintenance of lichen-rich forests is important. Finally, since the Cladonia species we study are large, charismatic, and perennial, our research can serve as a gateway for educating the public about the roles of fungi in ecosystems.

1 - Rutgers, the State University of New Jersey, Graduate Program in Ecology and Evoltuion, Environmental and Natural Resources Building, 1st Fl., 14 College Farm Rd, New Brunswick, NJ, 08901, USA
2 - Rutgers, the State University of New Jersey, Graduate Program in Ecology and Evolution, Environmental and Natural Resources Building, 1st fl., 14 College Farm Rd, New Brunswick, NJ, 08901, USA
3 - Rutgers, the State University of New Jersey, Rutgers Pinelands Field Station, 501 Four Mile Rd, New Lisbon, NJ, 08064, United States

Keywords:
Cladonia
lichen
Soil
nutrients
invasive species
allelopathy.

Presentation Type: Oral Paper:Papers for Sections
Session: 70
Location: Salon 10/The Shaw Conference Centre
Date: Wednesday, July 29th, 2015
Time: 4:00 PM
Number: 70010
Abstract ID:822
Candidate for Awards:A. J. Sharp Award,MSA Best Oral Presentation Award by a Graduate Student