Interactions between native prairie grasses and indigenous arbuscular mycorrhizal fungi: implications for reclamation of taconite iron ore tailing

Abstract

SUMMARYIn a gliiashouse experiment using coarse taconite iron ore tailing as the substrate, we examined interactions between the warm-season grasses Aiidropogoii gcrardii (big bluestem) and Schi~achyrium scopariiwi (little bluestem), and the cool-season grass Elymiis canadeiisis (Canada wild rye), and indigenous arbuscular mycorrhizal (AM) fungi from an adjacent fine tailing basin. Shoot dry mass (DM), P uptake, shoot P concentration, root DM, root length, spore density, percentage root length colonized, and length of external AM fungal hyphae were measured over a gradient of phosphate availability. Andropogon gerardii was highly dependent and responsive to inoculation at low P, whereas inoculation had no significant effect on the growth of S. scopariinii. Root DM and root lengths of both warm-season grasses were unaffected by mycorrhizal inoculation. Eiyvuis caiiadeiisis was responsive only at the lowest P level and not dependent on mycorrhizas; in fact, shoot DM, P uptake, root DM and root lengths were all greater in control than inoculated plants at moderate P levels. Despite a growth suppression, colonized root lengths for E. canadeiisis were approximately five times longer than warm-season grasses at low P levels, making it suitable as an early succession species for increasing mycorrhizal inoculum potential and thus enhancing the successful reclamation of coarse tailing deposits by more persistent, mycorrbizaldependent species.

Growth and nutrient uptake of arbuscular mycorrhizal maize in different depths of soil overlying coal fly ash

“…The restoration of soils in North American mining areas often involves converting old mine fields to prairie (Cook et al, 1988) or planting prairie species in highly disturbed habitats (Noyd et al, 1995). Removing topsoil from an unmined site adjacent to the mined area and using it to cover the mine spoil is a commonly accepted reclamation practice.…”

Plant species differ in their ability to reduce allocation to non‐beneficial arbuscular mycorrhizal fungi

“…Root colonization varied more widely in the C 3 than in the C 4 grasses, corresponding with stronger reductions in allocation to AMF at high phosphorus in C 3 than C 4 grasses. Root colonization is at best a weak predictor of carbon and nutrient exchange (Noyd et al 1995, Wilson and Hartnett 1998, Kaeppler et al 2000, Jifon et al 2002, so it is surprising that this response was associated with effective reductions in allocation to non-mutualistic AMF.…”

Fungos micorrízicos arbusculares em solos de área poluída com metais pesados

“…Griffiöen (1994), por exemplo, encontrou uma única espécie (Scutellospora dipurpurescens) em Agrotis capillaris, em solo contaminado com Zn, na Noruega; Noyd et al (1995) relataram apenas duas espécies em mina de taconita com excesso de Fe e Zn, em Minnesota; Ietswaart et al (1992) também identificaram apenas duas espécies em solo metalífero, contaminado por Zn, Cd e Pb, na Noruega. Pawlowska et al (1996) observaram seis espécies em rejeito de calamina na Polônia também contaminado com Zn, Cd e Pb.…”

“…Por essa razão, os fungos micorrízicos arbusculares (FMAs) e a simbiose micorrízica em solos poluídos têm sido objeto de diversos estudos em várias regiões do mundo (Gildon & Tinker, 1981;Ernst et al, 1984;Walker et al, 1984;Koske & Walker, 1986;Bethlenfalvay & Franson, 1989;Ietswaart et al, 1992;Christie & Kilpatrick, 1992;Sambandan et al, 1992;Raman et al, 1993;Weissenhorn et al, 1993;Griffiöen, 1994;Noyd et al, 1995;Pawlowska et al, 1996).…”