Adaptation of restoration target with climate change: the case of a coastal peatland

• Published in: Botany Vol. 98; no. 8; pp. 439 - 448
• Main Authors: Guêné-Nanchen, Mélina, D’Amour, Noémie, Rochefort, Line
• Format: Journal Article
• Language: English
• Published: 1840 Woodward Drive, Suite 1, Ottawa, ON K2C 0P7 NRC Research Press 01.08.2020
• Subjects: bog plants; bogs; botany; Carex; changement climatique; Chemical properties; climate change; coasts; contamination par l’eau de mer; Ecosystems; Electric properties; Electrical conductivity; Empetrum nigrum; environmental factors; Global temperature changes; land restoration; marais salé; mosses and liverworts; Myrica gale; New Brunswick; Peat; Peat-bogs; peatland restoration; peatlands; plant communities; restauration de tourbières; Revegetation; salt marsh; salt marshes; Saltwater encroachment; saltwater intrusion; sea level; Sea-water; seawater; seawater contamination; shrubs; Sphagnum; spontaneous revegetation; Sporobolus; Tidal marshes; vegetation; végétalisation spontanée; New Brunswick; Canada
• ISSN: 1916-2790; 1916-2804; 1916-2804
• DOI: 10.1139/cjb-2020-0050

As a rise in sea level is expected with climate change, peat-extracted peatlands located in coastal zones are more vulnerable to saltwater intrusion. Seawater contamination may prevent revegetation of typical bog species (e.g., Sphagnum, ericaceous shrubs) generally intolerant to saline conditions. Spontaneous revegetation was studied in a 27-year post-extracted bog that has been contaminated with seawater in New Brunswick (Eastern Canada). This study aimed (i) to evaluate spontaneous plant regeneration on saline but still acidic, organic soil; and (ii) to relate the recolonized vegetation patterns to the main environmental conditions. Of the seven plant communities found in the sea-contaminated bog, none were typical of bogs, and Sphagnum mosses were poorly represented. Plants communities and chemical properties were rather representative of salt marsh ecosystems (i.e., Carex paleacea, Sporobolus michauxianus, Empetrum nigrum, Myrica gale; neutral pH and nutrient-rich, namely P, Mg, and NH 4 + ). Areas with low levels of spontaneous revegetation were associated with harsh chemical conditions (i.e., acid pH, high electrical conductivity, and nutrient-poor). Considering the aggravating factors that will persist with climate change, restoration of coastal bogs contaminated with seawater should aim to re-establish salt marsh ecosystems, given that spontaneous revegetation patterns and chemical conditions clearly do not allow the establishment of bog plant communities.