Recovery of Tundra Vegetation Three Decades after Hydrocarbon Drilling with and without Seeding of Non-Native Grasses + Supplementary Appendices (See Article Tools)

Abstract

ABSTRACT. Oil and gas exploration conducted in the 1970s left a legacy of abandoned test wells with sumps, containing drilling waste, in the Mackenzie Delta region of Canada's Northwest Territories. One to two years after the test wells were decommissioned, a set of sites were seeded with non-native grasses and fertilized to test whether these treatments could accelerate vegetation recovery and prevent erosion. We sampled seeded and unseeded sumps and adjacent tundra vegetation in the Mackenzie Delta region three decades later to examine the impact of post-disturbance seeding treatments on site recovery. Plant species composition and environmental data were collected at 12 sump sites (6 seeded and fertilized and 6 unseeded and unfertilized) in lowland and upland tundra. Multivariate analyses using NMDS and perMANOVA indicated that in the lowlands, seeding and fertilization treatments had small but significant effects on plant species composition that differentiated seeded from unseeded sump caps. Plant communities on sump caps for all treatment types were significantly different from surrounding undisturbed tundra, even after more than 30 years of recovery. Seeded non-native grasses were found on both seeded and unseeded sumps, but not in the surrounding undisturbed tundra. Undisturbed tundra appears resistant to the spread of introduced agronomic grasses, but disturbed areas, such as sumps, provide areas of suitable habitat where non-native plants can persist.Key words: revegetation treatments; low Arctic tundra; plant invasion; oil and gas exploration; Kendall Island Bird Sanctuary; long-term monitoring RÉSUMÉ. L'exploration pétrolière et gazière effectuée dans les années 1970 a laissé des puits abandonnés et des bassins à boue contenant des résidus de forage dans la région du delta du Mackenzie, dans les Territoires du Nord-Ouest au Canada. Un à deux ans après que les puits ont été mis hors service, un ensemble de sites a été fertilisé et ensemencé avec des graminées non indigènes afin de vérifier si ces traitements pouvaient accélérer le rétablissement de la végétation et empêcher l'érosion du sol. Dans le but d'examiner l'incidence des traitements d'ensemencement sur la récupération des sites après trois décennies, nous avons échantillonné des bassins à boue ensemencés et non ensemencés, ainsi que la végétation de la toundra adjacente non perturbée dans la région du delta du Mackenzie. Sur 12 sites de bassins à boue (six sites ensemencés et fertilisés et six sites non ensemencés et non fertilisés) situés en basse et haute toundra arctique, des données environnementales ont été récoltées et des relevés de végétation ont été effectués. Les analyses multivariées (NMDS et perMANOVA) ont indiqué que les traitements d'ensemencement et de fertilisation ont eu un impact petit, mais significatif sur les communautés végétales au sommet des bassins à boue en basse toundra arctique. Les communautés végétales présentes au sommet des bassins à boue de tous types étaient significativement différentes de celles trouvées da...

Designing seed mixtures for restoration on alpine soils: who should your neighbours be?

“…Nevertheless, if the seeded species are strong competitors, they may persist and even dominate the vegetation (Kearns et al. ; Rydgren et al. ).…”

“…Under these conditions active restoration can speed up soil stabilization and vegetation recovery (Forbes & Jefferies ; Kearns et al. ).…”

Sixty‐year legacy of human impacts on a high Arctic ecosystem

“…Given the abiotic changes and the creation of bare ground, there is danger of colonization by non-native species, for example from soil attached to industrial machinery transported from the south. We recommend thorough cleaning of incoming machinery, as the establishment of non-native species may act as further dispersal points to other nearby human disturbances or even to naturally bare ground (Kearns et al 2015). Additionally, we recommend industry-assisted revegetation of disturbed ice-wedge troughs using native varieties of Eriophorum and Carex speciesas they have been shown to be successful colonizers (Chapin & Chapin 1980), there is likely additional seed bank of E. scheuchzeri (Forbes 1993) already present, and success rates of revegetation in wet areas are relatively high (Forbes & Jefferies 1999).…”

Successional dynamics of species composition, functional traits and assembly mechanisms during the 60‐year long history of agricultural transformations in subarctic tundra communities

“…Numerous studies have been conducted on the recovery of tundra vegetation after fires (Racine et al., 2004; Bret‐Harte et al., 2013; Heim et al., 2021; Hollingsworth et al., 2021), grazing (Kryazhimskii et al., 2011; Mörsdorf et al., 2021), trampling (Monz, 2002), and industrial impact (Sumina, 1994; Kevan et al., 1995; Forbes et al., 2001; Jorgenson et al., 2010; Kearns et al., 2015). However, we found only a few publications that focus on the restoration of tundra (alpine) vegetation after agricultural use (Kotelina et al., 1998; Archegova et al., 2002; Panyukov et al., 2005; Rada et al., 2021).…”