Mycorrhizas in Nothofagus From South America: What Do We Know From Nursery and Field Experiences?

NATALIA FERNÁNDEZ; SONIA FONTENLA; FACUNDO FIORONI; MATÍAS SOTO-MANCILLA; AYELEN CARRON; DENISE MOGUILEVSKY; PAULA MARCHELLI; CÉSAR MARÍN; M. CECILIA MESTRE

Mycorrhizal Fungi in South America: Biodiversity, Conservation, and Sustainable Food Production

Springer International Publishing

Año: 2022; p. 281 - 304

In the southern cone of South America, Subantarctic Temperate Forests develop on both sides of the Andes Mountains, in Chile and Argentina. These ecosystems are the southernmost forests on Earth and have been relatively undisturbed by man, which makes them unique and extremely valuable for diverse research purposes. They cover a narrow but long latitudinal strip from 35° S (Maule River, Chile) to 55° S (in the Southern extreme of Chile and Argentina) and are considered a biogeographic island due to their geographic discontinuity from the other forests of South America. The climate of these forests is cold temperate, with an average temperature ranging from 9.5 °C in the North to 5.4 °C in the South. Precipitation depends primarily on the humidity of the Pacifc Ocean and forms an abrupt decreasing gradient, fuctuating from more than 4000 mm in the West to 700 mm in the East over less than 50 km. Altitude gradients are also characteristic of this region, particularly at Northern latitudes where the Andes reach higher heights. Together with temperature and precipita- tion, elevation gradients also impose strong adaptive challenges for plants because of the marked changes in environmental conditions over relatively short distances, such as low temperatures, frosts and snow, high radiation, shorter growing season, and changes in soil characteristics. Disturbances of different origins (natural and anthropogenic) and at different scales have also infuenced, and still do, the structure and dynamics of Subantarctic Temperate Forests. Some of the main infuencing factors are those of geological origin, being volcanic eruptions relatively frequent high-magnitude disturbances in this region. Fire is another disturbance severely affecting these forests and probably the most impor- tant since the European colonization. At present, a large proportion of these forests is under protection (e.g., National Parks, natural reserves), but this was not always the case, and some regions have a long history of unsustain- able exploitation and use, mainly because of grazing, overexploitation, and the establishment of extensive plantations of fast-growing exotic species, such as pines. Therefore, these forests are characterized by a high heterogeneity imposed by prom- inent environmental gradients, which infuences species distribution and determines the occurrence of different forest formations.