Mycorrhizal fungi colonize many terrestrial plants and often result in
an increased uptake of P and several n-micronutrients. Little informa
tion is available on the relationships among vesicular-arbuscular endo
mycorrhizae (VAM), aquatic plants, and plant P concentrations. The maj
or objectives of this study were to measure the degree of VAM coloniza
tion of wetland plants, and to determine the relationship between colo
nization and plant P concentrations when sampled from two contrasting
water regimes (hydric soil with no surface water and hydric soil with
a minimum of 10 cm of surface water). Two semipermanent wetlands in La
ke County, South Dakota, were chosen for the study. Water regime did n
ot have a significant effect on total or organic soil P concentration.
Vesicular-arbuscular endomycorrhizal spore samples collected from wet
soils averaged 5000 spores kg-1 compared with 2740 spores kg-1 in dry
soils. The eight plant species evaluated to determine VAM colonizatio
n were reed canarygrass (Phalaris arundinacea L.), slough sedge (Carex
atherodes Spreng.), river bulrush [Scirpus fluviatilis (Torr.) Gray],
slender rush (Juncus tenuis Willd.), dogbane (Apocynum cannabinum L.)
, water smartweed (Polygonum amphibium L.), cattail (Typha X glauca Go
dr.), and wild licorice (Glycyrrhiza lepidota (Nutt.) Pursh). Vescular
-arbuscular endomycorrhizal colonization ranged from 78% (wild licoric
e) to none (slough sedge and slender rush). Roots from dry areas avera
ged 27% colonization compared with less than 1% in wet areas. Coloniza
tion levels of dogbane and reed canarygrass in dry zones were highly c
orrelated to plant P concentrations. The results of this study indicat
e that several wetland plant species develop substantial mycorrhizal a
ssociations, particularly in relatively dry environments.