Abstract Detail



Ecology

Molano-Flores, Brenda [1], Johnson, Sara [2], Janssen, Eric [3], Glass, Nicholas T [4], Whelan, Christopher J  [3].

Could road salt explain the decline of Thuja occidentalis in urban fens?

Within urban areas, natural communities and species face many biotic and abiotic challenges driven by anthropogenic activities.  During winter, copious amounts of road salts are used by highway departments to ensure safe winter driving conditions. As a result, natural areas in proximity to roads typically end up with an influx of salt runoff, often having negative impacts on neighboring habitat.  For example, road salts have been shown to infiltrate the water table, restrict nutrient uptake, mimic drought conditions at the root level, and cause foliar injury.  In this study, we explored the impact of salt concentrations on the germination of Thuja occidentalis (Northern White Cedar, Cupressaceae) found in two fens surrounded by urban development in northeastern IL USA.  We focused on Thuja occidentalis because although this evergreen tree is mostly found in northeastern North America, its southwest range extends into northeastern Illinois. Here, it is generally rare and uncommon outside of planted populations and land managers are concerned about its decline due to road salt pollution of delicate fen ecosystems.  Also, we assessed several aspects of the reproductive ecology of Thuja occidentalis, including cone biomass, seed biomass, seed set, and seed morphometrics.  Plant material (i.e., cones and seeds) was obtained from 5 localities (2 fens, 2 arboreta, and 1 commercial facility).  Salt solutions for germination ranged from 0 to 400 mM and morphometric measurements were taken using IMGJ software.  Overall, significant differences were found among sites for seed germination and the majority of the reproductive metrics measured.  The results from this study provide additional support for the detrimental impacts of road salts on plants.  Lastly, reproductive differences among Thuja occidentalis populations could further explain the decline of the species at one of the fens in our study.


1 - University Of Illinois, Illinois Natural History Survey, 1816 South Oak Street, Champaign, IL, 61820, United States
2 - Illinois Natural History Survey, 1816 S. Oak St, MC 652, Champaign, IL, 61820, United States
3 - Illinois Natural History Survey, 1816 S Oak Street, INHS, Forbes Building, Champaign, IL, 61820, US
4 - University of Illinois-Chicago, Biological Sciences , 845 W. Taylor St., Chicago, IL, 60607, USA

Keywords:
Urban ecosystems
Thuja occidentalis
Germination
reproduction
road salts.

Presentation Type: Oral Paper
Number: ECO5001
Abstract ID:106
Candidate for Awards:None


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