Quantifying carbon stocks and functional diversity of roadside ecosystems – A case study in Quebec, Canada

Abstract

The present study aimed to evaluate the capacity for carbon storage of ecosystems located on areas bordering paved or travelled roads, using the southern part of Quebec (Canada) as a case study. About 59 roadsides covering a variety of visually contrasting vegetation assemblages (from herbaceous covers to forest stands) and soil conditions were inventoried to quantify the carbon stocks of above- and belowground pools, including living and dead biomass and soils. The functional diversity and identity of overstory and understory vegetation were analyzed to explore their links with carbon storage. The highest total ecosystem carbon content was observed in sites dominated by trees and shrubs, with an average of 282.16 Mg ha¯¹ . Functional diversity mediated by functional dispersion (FDIS) of both overstory and understory vegetation was a significant predictor of aboveground carbon stocks on roadsides. FDIS of overstory vegetation (trees and shrubs) and functional richness (FRIC) of understory vegetation were also significant predictors of the total carbon storage of ecosystems. In contrast, we found a negative relationship between overstory functional identity mediated by community-weighted means of leaf nitrogen content (CWM-N) and total ecosystem carbon storage (including aboveground and soil). Our results suggest that roadside ecosystems can be important carbon sinks, and species with varied functional traits could promote carbon storage in these sites.