LAUSR

Old-growth temperate rainforests, located at the Patagonian and Valdivian regions of southern Chile and Argentina, represent unique ecosystems in South America. These forests are characterized by a large amount of precipitation, with very little to none atmospheric pollution, and a flora derived from Gondwanian elements. The mycorrhizal traits of the dominant plants of these ecosystems are also exceptional: the angiosperm Nothofagus spp. associates with ectomycorrhizal (EM) fungi, while the native conifer species associate with arbuscular mycorrhizal (AM) fungi, an opposite pattern to that of the Northern hemisphere. On this chapter we present an overview of the mycorrhizal types of 245 vascular plant species, where 187 species associate with AM fungi, seven with EM fungi, 14 with other mycorrhizal types, and 37 plant species are non-mycorrhizal. On these southern Chile ecosystems, we also show the role of mycorrhizal fungi on crucial ecosystem processes, as biogenic weathering, and their potential use as ecological restoration tools for the re-establishment of native flora. Specifically, we found that the co-inoculation of two EM fungi species significantly increases the growth of Nothofagus spp. as compared to singular inoculations. On these temperate rainforests, mycorrhizal fungi play key roles on nutrient cycling, maintenance of biodiversity, and ecosystem productivity.