Rk. Noyd et al., INTERACTIONS BETWEEN NATIVE PRAIRIE GRASSES AND INDIGENOUS ARBUSCULARMYCORRHIZAL FUNGI - IMPLICATIONS FOR RECLAMATION OF TACONITE IRON-ORETAILING, New phytologist, 129(4), 1995, pp. 651-660
In a glasshouse experiment using coarse taconite iron ore tailing as t
he substrate, we examined interactions between the warm-season grasses
Andropogon gerardii (big bluestem) and Schizachyrium scoparium (littl
e bluestem), and the cool-season grass Elymus canadensis (Canada wild
rye), and indigenous arbuscular mycorrhizal (AM) fungi from an adjacen
t fine tailing basin. Shoot dry mass (DM), P uptake, shoot P concentra
tion, root DM, root length, spore density, percentage root length colo
nized, and length of external AM fungal hyphae were measured over a gr
adient of phosphate availability. Andropogon gesardii was highly depen
dent and responsive to inoculation at low P, whereas inoculation had n
o significant effect on the growth of S. scoparium. Root DM and root l
engths of both warm-season grasses were unaffected by mycorrhizal inoc
ulation. Elymus canadensis was responsive only at the lowest P level a
nd 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 lengt
hs for E. canadensis were approximately five times longer than warm-se
ason grasses at low P levels, making it suitable as an early successio
n species for increasing mycorrhizal inoculum potential and thus enhan
cing the successful reclamation of coarse tailing deposits by more per
sistent, mycorrhizal-dependent species.