Projects

The diversity and role of root-associated fungi in saltmarsh and seagrass plants and implications fo

End Date: 1-31-07

Abstract

Saltmarsh and seagrass are known to provide important vegetated habitats for many species of fish and invertebrates, some of which are of commercial and/or recreational importance, as well as for many types of wading birds and endangered species, such as manatees and sea turtles. Additionally, these habitats may help to protect reefs by binding sediments, cleaning coastal waters, and providing coastal defense from erosion. Saltmarshes and seagrass meadows, however, are declining worldwide primarily due to human-induced disturbances.

The loss of these valuable habitats gives urgency to protect and conserve these important resources. In efforts to overcome the loss of these valuable habitats, seagrass and saltmarsh restoration projects are on the increase. However, the costs of these restoration programs are often very high and, unfortunately, there are as many failures as there are successes. Therefore, strategies need to be developed to increase the success rate of restoration projects.

We plan to investigate the role of mycorrhizae in seagrass and saltmarsh survival rates. Mycorrhizae are symbiotic associations that form between the roots of most plant species and fungi. Nutrients taken up by the mycorrhizal fungi can lead to improved plant growth and reproduction. The benefits for plants with mycorrhizal symbioses can be characterized either agronomically by increased growth and yield, or ecologically by improved fitness. Mycorrhizal plants are often more competitive and better able to tolerate environmental stresses than are non-mycorrhizal plants. This interaction between plants and fungi is well understood and documented in terrestrial plants, but the knowledge of mycorrhizae in salt marshes and seagrasses is scarce.

We consider that mycorrhizal associations are important in understanding plant nutrient uptake efficiency, and suggest this is a causal mechanism for the poor restoration success of saltmarsh and seagrass plants. The main objective of the proposed work is to investigate the presence and ecological role of mycorrhizal fungi in estuarine plant habitats found along the Mississippi coastline and to determine the effect of the presence of mycorrhizal fungi on seagrass and salt marsh restoration, survival and function.

Objectives

The proposed work will investigate the presence and ecological role of mycorrhizal fungi in estuarine plant habitats found along the Mississippi coastline, and will determine the effect of the presence of mycorrhizal fungi on seagrass and salt marsh survival, function, and restoration success. 

Methodology

The project will have two main phases. In year one, we will focus on collecting and identifying the diversity of mycorrhizal fungi from a range of seagrass and saltmarsh plants and locations. 

Rationale

The Mississippi-Alabama Sea Grant Consortium (MASGC) 2005-2010 strategic plan calls for studies that address the health and restoration of coastal habitats, in view of rapidly diminishing estuarine condition resulting from anthropogenic impacts. We plan to investigate the role of mycorrhizae in seagrass and saltmarsh survival rates. Mycorrhizae are symbiotic associations that form between the roots of most plant species and fungi. Nutrients taken up by the mycorrhizal fungi can lead to improved plant growth and reproduction in restoration projects.