Evaluating Letharia vulpina transplants for bioindication of nitrogen deposition

Abstract

The epiphytic lichen Letharia vulpina has been commonly sampled in-situ for nitrogen (N) deposition biomonitoring studies but has never before been transplanted for this purpose. In the high-elevation wilderness areas of southern California Letharia vulpina is generally uncommon, making in-situ sampling difficult. In this study, we compared thallus N accumulation between in-situ Letharia vulpina reference samples from the relatively low N deposition environment of the northern Sierra Nevada mountains and Letharia vulpina transplants that were deployed at nine plots of varying climatic and N deposition regimes in the southern Sierra Nevada mountains for 12 months. Survival of transplants was low (33%) and only occurred at the plots within the current range of Letharia vulpina. Transplant N concentrations became higher than those of the reference samples, while transplants that died had a net loss of N. Transplants that survived had strong relationships of N concentrations to N deposition and approached N concentrations of in-situ Letharia vulpina at the same plots. At the same time, reference plot N concentrations in a relatively clean environment increased substantially from early summer 2020 to 2021, presumably in response to extended exposure to smoke from huge wildfires in summer and fall of 2020.

Citation

Kovasi, Adrienne; McCune, Bruce; Jovan, Sarah. 2023. Evaluating Letharia vulpina transplants for bioindication of nitrogen deposition. The Bryologist. 126(4): 447-456. https://doi.org/10.1639/0007-2745-126.3.447.