Canadian Forest Service Publications
Germination and early growth of boreal understory plants on 3 reclamation soil types under simulated drought conditions. 2017. Pinno, B.D.; Li, E.H.Y.; Khadka, B.; Schoonmaker, A. Native Plants Journal 18(2):92-105.
Issued by: Northern Forestry Centre
Catalog ID: 38901
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Forest land reclamation after industrial activity requires the re-establishment of self-sustaining ecosystems consisting of native plant species. This greenhouse study determined the germination and early growth of the understory species Leymus innovatus (Beal) Pilg. (Poaceae; hairy wild rye), Chamerion angustifolium (L.) Holub (Onagraceae; fireweed), and Solidago canadensis L. (Asteraceae; goldenrod) in 3 operational reclamation soil types (forest floor-mineral mix, peat-mineral mix, and clay topsoil) under various water stress conditions. Germination of the 3 species occurred only when a standard, high moisture level was maintained; there was essentially no germination when watering was restricted. Furthermore, C. angustifolium germination was greatest in the forest floor-mineral mix. Seedling biomass production in all species and in all soil types increased with higher watering rates; however, the growth increase with watering was lessened on the peat-mineral mix and clay soils, likely because of limited nutrient supplies. Among the species studied, C. angustifolium had the greatest biomass growth potential in higher watering treatments but it was more sensitive to drought with higher mortality in the lower watering treatments. By contrast, L. innovatus and S. canadensis had greater relative biomass production in drier conditions and had greater root:shoot ratios than did C. angustifolium. These results can be used operationally by reclamation practitioners to aid in the development and deployment of appropriate native plant seed mixes to the correct reclamation site and soil types.
Plain Language Summary
Reclaiming forest land after industrial activity such as oil and gas extraction requires re-establishing self-sustaining ecosystems consisting of native plant species. This greenhouse study was intended to help those involved in reclamation choose native plant seeds that will thrive in the particular soil and climate of a reclaimed site. It determined the germination and early growth of three common native species (hairy wild rye, fireweed and goldenrod) found in the understory (the vegetation underneath the forest canopy). Their growth was tested in different soil types and watering levels found in reclamation sites. Germination of all three species occurred only when a standard, high moisture level was maintained and did not occur when watering was restricted. Seedlings produced more biomass as a result of more watering, in all species and soil types. However, the growth increase with watering was limited on certain soil types because of limited nutrient supplies. The species that had the greatest growth potential was also most sensitive to drought. These results can be used to aid in choosing and using appropriate native plant seed mixes in reclamation sites.