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theses

The New Jersey pine barrens and the serpentine barrens represent two barren ecosystems exhibiting different soil chemistry. Among the unique characteristics of both soil types, serpentine soils are known to contain high concentrations of naturally occurring heavy metals (Ni, Cd, Cr, Co). Arbuscular mycorrhizal fungi (AMF) and dark septate endopyphytes (DSE) are beneficial fungi which form a mutual symbiosis with most land plants; especially with plants in conditions such as nutrient poor soil, or phytotoxic conditions. This study investigates how soil conditions found in the two barren ecosystems influences plant success and the root colonization by beneficial fungi of Schizachyrium scoparium and Panicum virgatum. Root colonization by arbuscular mycorrhizae and, particularly dark septate endophytes was greater in serpentine soil than pine barrens. In a reciprocal transplant experiment, soil type was a main determinant of seed germination, survival and plant growth. Seedling survival appeared to be greater when seeds were grown in non-native soil for both plant species. In the soil amendment experiment, where pH and Ni concentration of pine barrens soil was increased to that similar to serpentine barrens soil, we found no germination of either plant species in the Ni amended soil and significantly less growth in the Ni/pH amendment, compared to control of pH amended soil. Significantly greater root colonization by both arbuscular mycorrhizal and dark septate endophytes occurred on switchgrass in the Ni/pH amended soil compared to control or pH amendment, suggesting a greater fungal dependency of plants in stressed conditions. This study has provided a comparison of pine barrens soil and serpentine barrens soil, as well as how the soil conditions present at each barren ecosystem influence root colonization by AMF and DSE.

ETD_7373

M.S.

Includes bibliographical references

by Jocelyn Wardlaw

doi:10.7282/T3J38VQW

ETD graduate

The author owns the copyright to this work.