Effects of traffic-derived Cu pollution and climate change on arboreal Collembola in Western Washington, USA

Abstract

Increased demand for travel in the Pacific Northwest has lead to higher inputs of heavy metal pollutants in the region, many of which have been shown to increase in toxicity for various organisms at higher temperatures. I investigated the effects of Cu and supraoptimal temperatures on a moss-dwelling and soil-dwelling species of Collembola. I reared Folsomia candida Willem under laboratory conditions and collected Choreutinula americana sp. nov. from two sites representing high (Seattle) and low (Hoh Rainforest) background Cu levels in Western Washington. I first exposed Collembola to aqueous Cu solutions ranging from 0.1 to 10,000 ppm to establish LC25 and LC50 values. I then exposed each population to their respective LC25 and LC50 concentrations at three temperature regimes based on ambient temperatures, B1 (+1.8°C), and A2 (+3.5°C) IPCC climate change scenarios. I found C. americana to be more sensitive to Cu than lab-reared F. candida, and increased temperatures greatly lowered both species tolerance to Cu. The results of this study highlight the impact that interactions between climate change and pollutants have on ecosystem health.