Mycorrhizal dynamics of three woodland herbs of contrasting phenology along topographic gradients

Abstract

Vesicular‐arbuscular mycorrhizal (VAM) dynamics of three woodland herbs of differing phenology were examined along contiguous topographic gradients in two southwestern Ohio forests during 1992‐1994. Cardamine concatenata (Brassicaceae) exhibited VAM colonization only during senescence in May, whereas Trillium flexipes and Smilacina racemosa exhibited robust VAM development throughout the year. The lowest mean percent root length colonized (PRLC) for T. flexipes and S. racemosa was 38.3% and 37.7%, respectively, while the greatest was 80.2% and 80.8%, respectively. Overall, analysis of variance (ANOVA) indicated significant seasonal effects with summer months having higher mean PRLC, and winter and early spring months having the lowest. ANOVA also indicated a significant effect due to topography, with uplands and slopes having greater mean PRLC than lowlands. The significantly lower mean PRLC for both T. flexipes and S. racemosa may have reflected higher phosphate availability in the spring, cooler temperatures, and/or moister conditions. The significantly lower mean PRLC in lowland positions may be due to greater soil moisture throughout the year. These results support the hypothesis that VAM development is lower in moister topographic positions, however, they do not support the hypothesis that VAM development would increase with decreasing P availability. Consequently, moisture appeared more important than P in regulating VAM development in these sites.

Growth and reproductive characteristics of the columnar cactus Stenocereus queretaroensis and their relationships with environmental factors and colonization by arbuscular mycorrhizae

“…Buxbaum show only traces of root colonization by AM fungi (Carrillo-García et al 1999). Our finding of a lower percentage of root length colonized by arbuscules at ZTJ and SRZ than at AJ corroborate these studies and provide further evidence that the capacity for symbiosis with AM fungi is associated with favorable conditions for photosynthesis by the host plant (DeMars andBoerner 1995, Smith andSmith 1996).…”

Foliar Nutrient Dynamics and Resorption in Naturalized Lonicera maackii (Caprifoliaceae) Populations in Ohio, USA

“…The higher resorption of P in bottomland sites may, in part, be reflected by the means in which Lonicera maackii obtains P. The Caprifoliaceae form vesicular-arbuscular mycorrhizae, which increase the absorption of soil P (Trappe, 1987). DeMars and Boerner (1995) showed that there were significantly lower levels of mycorrhizal colonization in herbaceous understory plants in the moister bottomlands of the study sites. Hence, the combination of low soil P availability and lower mycorrhizal development may necessitate greater P conservation.…”

“…Standard errors of the mean are given in parentheses. Data are adapted from DeMars and Runkle (1992), DeMars and Boerner (1995 (Chapman, 1965).…”

Arbuscular mycorrhiza and dark septate endophyte fungal associations of Oryza sativa L. under field condition: colonization features and their occurrence

“…Rice bran oil is used for making soap and cosmetics (8). Certain studies revealed that AM fungi root colonization has seasonal dynamics (9,10). Rice plants readily form mycorrhizal associations under upland conditions and limited colonization occurs under submerged conditions due to the anoxic environment (11).…”