Germination and early growth of boreal understory plants on 3 reclamation soil types under simulated drought conditions
Pinno, B.D, E.H.Y. Li, B. Khadka and A. Schoonmaker. 2017.
Abstract
Forest land reclamation after industrial activity requires the re-establishment of self-
sustaining ecosystems consisting of native plant species. This greenhouse study deter-
mined 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.
Key Words
reclamation, boreal forest, understory plants, Leymus innovatus, Chamerion angustifolium, Solidago canadensis, Poaceae, Onagraceae, Asteraceae
