Fungi Facilitates Revegetation Following Fire Restauracao Do Solo

Fungi Facilitates Revegetation Following Fire By MIKE AMARANTHUS AND DAVE RUSSELL

Michael Amaranthus, Ph.D. is an associate professor (adjunct) in the Department of Forest Science at Oregon State Univ Mycorrhizal Applications, Inc. David Russell is a Bureau of Land Management Forester with BLM in Medford, Oregon.

Introduction

Wildfires are a typical, even beneficial, event in the life cycle of many plant communities. However, decades of fire suppres encroachment into areas with large accumulations of fuel have resulted in dramatic increases in fire severity. The results ha so hot that soil erosion and plant recovery is a great concern.

Resource managers and erosion control specialists are then forced into frantic action to quickly establish protective ground native grasses that stabilize soils and help alleviate the destructive power of high intensity rainfall. This goal can be achieve understanding of how plants have naturally restored damaged ecosystems. This paper explores the use of mycorrhizal fun with most plant species in the post-fire reestablishment of native plants.

The Root of the problem

Hidden from view, beneath the soil surface are a multitude of beneficial soil organisms that are key to plant establishment b resource professionals. Over the last decade we have learned much regarding the role of soil organisms in the recovery an post-fire vegetation following wildfire. Mycorrhizal fungi are a vital group of beneficial soil organisms critical for plant surviva communities.

Mycorrhizal fungi should be familiar to us, after all, they form a symbiotic relationship with approximately 90% of all plant sp habitats. Even though mycorrhizae are as common to the roots of plants as cloroplasts are to the leaves, they are common assessments for revegetation of severely disturbed lands. Fortunately, recent studies have examined the impact of wildfire colonization of post-fire plant communities (Amaranthus et al. 2004, Amaranthus and Trappe 1993, Vilarino and Arines. 199 1994). Other studies have examined the successful use of mycorrhizal inoculum to encourage the re-establishment of post (Amaranthus et al. 2003, Bellgard et al. 1994; Rashid, et al 1997, Pattinson et al. 2001a, 2001b).

In 2002 over 500,000 acres burned in wildfire in northern California and southern Oregon. We report recent data on natura seeded native grass community establishment following two of these fires, Squires Peak and Antelope, on Bureau of Land lands in southwest Oregon (figure 1).

Fire effects on soil and flora

The overall effects of fire on ecosystems are complex, ranging from the reduction or elimination of above-ground biomass t ground physical, chemical and microbial mediated processes. Since a key component of overall ecosystem sustainability o recovery is tied to the soil's physical, chemical, and biological functions and processes. Depending on several fire severity below-ground components can be either beneficial or harmful to the entire ecosystem.

For example, low intensity burning can promote a herbaceous flora, increase various plant nutrients, and thin overcrowded can foster healthy soil microbial systems. Severe fire, however, can cause changes in successional rates, alter above- and species composition, produce rapid or decreased mineralization rates, alter carbon/nitrogen ratios, and cause subsequent through volatilization, accelerated erosion, leaching or denitrification. Changes in soil hydrologic functioning, degradation o properties, decreases in micro- and macro fauna, and dramatic reductions in beneficial soil microbial populations.

The mycorrhizal relationship

Mycorrhizae are the symbiotic association between specific soil fungi and plant roots that exists for the vast majority of the in their native habitats. The mycorrhizal relationship is the "norm" in native habitats. Mycorrhizal populations, however, are eliminated in severely burned soils following wildfire. Research has established that the growth of mycorrhiza-dependent p affected by availability of mycorrhizal fungi (Steinfeld and Amaranthus 2003, Allen, 1991; Amaranthus and Perry, 1987, 198 1992). Mycorrhizae and their interactions profoundly affect plant reestablishment through capture and uptake of nutrients, p pathogens, maintenance of soil structure and buffering against moisture stress. Mycorrhizae are critically important followin tiny filaments of the fungus radiate out from the plant roots to occupy large expanses of the soil volume allowing plants to s and establish (figure 2). The filaments actually attach to and penetrate the outer cells of the plant root, effectively becoming root itself by taking up water and plant nutrients in the process.

Both angiosperm and gymnosperm plant species that recolonize burned areas belong to families that dominantly form myc 1987). Two broad groups of mycorrhizal fungi are involved: ectomycorrhizal fungi (EMF) species and arbuscular mycorrhiz species, formerly known as "endomycorrhizal" fungi (Marx and Kuslowski 1976; Sanders et al. 1975). The approximately 2 species are the dominant mycorrhizal types worldwide, forming mycorrhizae with approximately 80 percent of all plant spec which form new mycorrhizae are spores, hyphal filaments, and colonized root fragments. AMF propagules are produced be