An overview of arbuscular mycorrhizal fungal composition, distribution and host effects from a tropical moist forest

Specificity between Neotropical tree seedlings and their fungal mutualists leads to plant–soil feedback

“…Annual rainfall is 2600 mm, with 90% of precipitation falling from late April to mid-December, which is then followed by a pronounced dry season (Windsor 1990). AMF spore communities of BCI and its surrounding land masses are diverse (Mangan et al 2004, Herre et al 2005, and primarily dominated by members of the genus Glomus (Mangan et al 2004).…”

“…Prolonged physiological changes may set the stage for succession of associated AMF communities within an individual tree. Therefore, the suite of AMF that is most beneficial at the seedling stage may not be the same suite that is most beneficial to adults (Kiers et al 2000, Herre et al 2005). In our study, positive feedback was detected among Apeiba seedlings of closely aged cohorts that were undoubtedly physiologically similar.…”

“…These fungi form symbiotic relationships with plants in which the fungus often provides the plant with the ability to access scarce resources in return for carbohydrates. Although in most cases this relationship is mutualistic, the net benefit that a single plant species receives depends on the identity of the fungus with which it is associated (van der Heijden et al 1998, Bever 2002a, Klironomos 2003, Herre et al 2005. Likewise, levels of root colonization and spore production of a given AMF species depends on the identity of the host plant (Bever et al 1996, Eom et al 2000, Husband et al 2002.…”

“…Whether similar AMFmediated processes also occur in other systems such as those dominated by longer-lived hosts (e.g., trees) remains largely unstudied. Neotropical forests serve as excellent study systems for the exploration of AMF-mediated processes in tree communities, because tropical AMF are diverse and heterogeneously distributed (Picone 2000, Lovelock et al 2003, Mangan et al 2004, Herre et al 2005, and the majority of Neotropical trees, like temperate grasses, are dependent on AMF for establishment and growth (Siqueira et al 1998, Zangaro et al 2003. The high dependency of tropical tree seedlings on AMF may be particularly important because the set of factors that affect seedling dynamics in tropical forests is thought to be one of the most important ecological filters that determine the composition of reproductive adults (Connell et al 2005).…”

Ecological Implications of Anti-Pathogen Effects of Tropical Fungal Endophytes and Mycorrhizae

“…Nonetheless, for both foliar endophytic fungi (FEE) and arbuscular mycorrhizal fungi (AMF) there is accumulating evidence that these fungi provide previously under-appreciated beneficial effects for their hosts. Specifically, recent work has demonstrated that, under some circumstances, both types of endophytes (FEE in leaves and AMF in roots) can enhance host resistance against attack and damage by pathogens (Smith 1988, Smith and Gianinazzi-Pearson 1988, Newsham et al 1995, Shaul et al 1999, Borowitz 2001, Evans et al 2003, Garmendia 2004, Holmes et al 2004, Herre et al 2005a, b, Rubini et al 2005, Van Bael et al 2005; but see Faeth 2002). Discovering what these effects are, clarifying their proximal mechanisms, and understanding the ultimate selective pressures that influence them are primary goals for the study of the evolutionary ecology of endophytehost interactions (Carroll 1991, Herre et al 1999).…”