Grantee Research Project Results
Mycorrhizal Ecology of Sporobolus wrightiiEPA Grant Number: U914993
Title: Mycorrhizal Ecology of Sporobolus wrightii
Investigators: Kennedy, Linda J.
Institution: Arizona State University
EPA Project Officer: Lee, Sonja
Project Period: January 1, 1996 through April 21, 1999
Project Amount: $102,000
RFA: STAR Graduate Fellowships (1996) RFA Text | Recipients Lists
Research Category: Academic Fellowships , Ecological Indicators/Assessment/Restoration , Fellowship - Ecology
The goal of this research project is to develop baseline, ecological information on arbuscular mycorrhizal (AM) associations, an aspect of plant ecology that has played an important role in restoration projects of other ecosystems. The host plant chosen for my study is Sporobolus wrightii Munro ex Scribn, giant sacaton, a perennial bunchgrass that was once a dominant species in riparian zones of the Southwest, and currently is included in many restoration plans. Restoration projects may be enhanced by inoculation with populations of AM fungi that are most effective, if mycorrhizal associations can be identified that promote the fitness and speed recovery of giant sacation grasslands. Objectives of this project include: (1) determination of AM fungal species diversity found in the rhizospheres of S. wrightii plants from existing grasslands along rivers and streams of southern Arizona; (2) evaluation of changes in the level of colonization in giant sacation roots throughout an annual period; and (3) quantification of the effectiveness of mycorrhizal populations on seedling emergence, survivorship, and growth parameters of S. wrightii across a gradient of phosphorus concentrations.
Field sites supporting giant sacaton will be sampled to determine the composition of AM fungal populations associated with S. wrightii. To determine levels of AM fungal colonization found in S. wrightii, roots from each field soil core are immediately removed, washed, cut into 1-cm segments, placed into individual root capsules, and stored in formalin acetic acid. To examine the effects of AM fungal inoculation on the emergence, survivorship, and growth of S. wrightii, mature seed will be collected from the panicles of well-established plants.
Efforts to restore sacaton grasslands as a component of arid land riparian systems will continue. If infection with appropriate AM fungal populations promotes seedling survivorship and growth, these restoration efforts may be enhanced by establishment of mycorrhizal networks. Mycorrhizal associations may serve as a biotic fertilizer, reducing the amount of time, seed, and soil amendments needed to turn abandoned farmlands to sacation grasslands.