Effects of Endophyte Infection in Tall Fescue (Festuca arundinacea: Poaceae) on Community Diversity

Abstract

Recent studies have suggested that the presence of endophytes in tall fescue can lead to decreased species richness in the associated plant community. To assess the generality of this hypothesis, a field study tested the effects of endophyte infection on a 3-yr-old successional field dominated by Festuca arundinacea. The potential importance of endophyte infection relative to other environmental factors was tested by including two additional treatments: the effects of soil fertility and mowing. Contrary to previous studies, a positive relationship was found between endophyte infection frequency and diversity ( ,2 N p 23 F p 5.23 R p 0.19 P ! 0.03 strong interaction was found between the mowing treatment and endophyte infection frequency in predicting diversity ( , , , ), where the maximum species richness was present in 2 N p 22 F p 36.1 R p 0.84 P ! 0.0001 plots that were both mowed and highly endophyte infected. The relationship between endophytes and diversity varied through the successional continuum (the mowing treatments) but was generally positive. The soil in mowed plots was drier than in unmowed plots ( , , ). We suggest that heavy mowing t p 2.1 df p 28 P ! 0.05 decreases soil moisture levels enough to reduce the interspecific competitive ability of infected F. arundinacea, thereby promoting local diversity. Endophyte presence is important, but the previously reported negative relationship between endophyte infection and community diversity is probably overly simplistic in complex ecological settings.

Fungal Endophytes and their Role in Plant Protection

“…Most studies have been conducted with pasture endophytes focusing on a few plant species: Lolium perenne L. and Festuca arundinaceae Shreber [23][24][25][26][27][28][29][30][31], and some other graminae [32][33][34] since the toxic effects of balansiaceous (Ascomycotina) fungal alkaloids on cattle have been long known [13]. These studies have now been extended to other plant and endophyte species [35][36][37][38][39][40][41][42][43][44][45].…”

Soil organic carbon fractions differ in two contrasting tall fescue systems

“…Tall fescue is an important cool-season perennial forage grass commonly used for turf and soil conservation around the world (Rahman and Saiga 2005;Spyreas et al 2001;Stuedemann and Hoveland 1988). It covers a significant area of the eastern USA, and is increasingly prevalent in Africa, Australia, China, New Zealand, and South America, (Rudgers and Clay 2007).…”

The Biology of Canadian Weeds. 141. Setaria faberi Herrm.

“…Don., and the shrubs Elaeagnus umbellata Thunb., Rubus pensilvanicus Poir., and Rosa multiflora Thunb. (Spyreas et al 2001). In old-field communities in New Jersey, S. faberi was the dominant species and highly competitive with Ambrosia artemisiifolia, Calystegia sepium L., Digitaria sanguinalis, Oxalis stricta, Panicum dichotomiflorum Michx., and Solanum carolinense (Hunt et al 1979;Facelli and Pickett 1991a).…”