Microbial Interactions in the plant-soil continuum: Research results presented at the Workshop “Mycorrhizal Symbiosis in the Southern Cone of South America”

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Roberto Godoy1, Patricia Silva-Flores2,3, Paula Aguilera4, César Marín1*
1Instituto de Ciencias Ambientales y Evolutivas, Universidad Austral de Chile,Valdivia,
Chile. 2Centro de Estudios Avanzados en Fruticultura -CEAF, Rengo, Chile.3Departamento
de Botánica, Universidad de Concepción, Concepción, Chile. 4Center of Amelioration
and Sustainability of Volcanic Soils, BIOREN-UFRO, Universidad de La
Frontera, Temuco, Chile. *Corresponding author: cesar.marin@postgrado.uach.cl
Microbial Interactions in the plant-soil continuum:
Research results presented at the Workshop “Mycorrhizal
Symbiosis in the Southern Cone of South America”

2 Editorial
Godoy et al.
The Southern Cone of South America sustains sev-
eral types of ecosystems such as old-growth temper-
ate rainforests, Mediterranean woodland and scrub
forests, Pampa, and many others. These ecosystems
are of global importance; for example, the temperate
rainforests in this region account for more than half
of all southern hemisphere temperate rainforests. Fur-
thermore, Chilean Mediterranean ecosystems, which
are unique to South America, are one of only ve
Mediterranean regions in the world. Also, and despite
the harsh conditions, agroecosystems on this region
sustain a great amount of productivity. Since the Ho-
locene, the oristic composition of all ecosystems
found in the Southern Cone of South America has
been stable and is marked by high endemism resulting
from Pleistocene glaciations and postglacial climatic
uctuations. Specically, the Chilean Coastal Range
served as a glacial refugium for plants, causing this
area to have high plant diversity at the family level
and isolated monotypic genera. The Coastal Range
bedrock is highly weathered, and oceanic atmospher-
ic nutrients have a signicant inuence. In contrast,
nutrient inputs to steep slopes of the Andes Range
are mostly generated by young volcanic ash deposits
and weathered basaltic volcanic scoria. Overall, these
ecosystems have extreme environmental, edaphic,
and orographic conditions that are enhanced by earth-
quakes and volcanic activity. Furthermore, the soil of
these ecosystems is characterized by a high retention
of organic matter, low plant available phosphorus, and
phytotoxic aluminum levels. As a consequence of the
unique conditions of these ecosystems, several oris-
tic types can be found in the Coastal and Andes Rang-
es, for example: native conifer-dominated forests, e.g.
Fitzroya cupressoides, angiosperm dominated forests
Nothofagus spp., Valdivian forests, and others.
One important trait of almost all plants of the South-
ern Cone of South America is their mycorrhizal as-
sociation type. For example, ectomycorrhizal (EM)
forms are dominant in Nothofagus forests, and ar-
buscular mycorrhizal (AM) associations are usually
found with subordinate plants, though the contrary
pattern is seen in native coniferous forests. Addition-
ally, AM associations are dominant in Mediterranean
forests, though EM associations are found with few
tree species. Overall, however, soil fungal communi-
ties, and specically mycorrhizal associations, have
been poorly studied in the Southern Cone of South
America. The rst mycorrhizal studies in Chile deter-
mined the mycorrhizal dominance of conifer trees and
Nothofagus species as well as the mycotrophic status
of the vascular ora of several vegetation types. Some
recent molecular studies have been focused on the
study of soil fungal assemblages in North-Patagonia,
specically AM and EM fungi in Chilean (Coast and
Andes) and Argentinean Nothofagus and coniferous
forests. Other molecular studies have sought to char-
acterize AM and orchid mycorrhizal (OM) fungi of
the Mediterranean forests of Central Chile. Recent
global studies have also included Chilean and Argen-
tinean coniferous forests, comparing all fungal asso-
ciations, or specically AM fungal communities.
This Special Issue of the Journal of Soil Science and
Plant Nutrition, contains research results presented at
the Workshop: “Mycorrhizal Symbiosis in the South-
ern Cone of South America,” as well as research
within the general topic of microbial-plant-soil inter-
actions. The workshop aimed at establishing the status
of research of mycorrhizal symbiosis in the Southern
Cone of South America. Furthermore, the workshop
aimed to facilitate collaboration between researchers,
students, and the mycorrhizal scientic community of
Argentina, Chile, and other countries.
The workshop had seven key lectures by: Álvaro G.
Gutiérrez (Universidad de Chile, Chile), Andrea Pre-
moli (Universidad Nacional del Comahue, Argentina),
Götz Palfner (Universidad de Concepción, Chile), Fer-
nando Borie and Pablo Cornejo (Universidad de La

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Editorial
Frontera, Chile), Maarja Öpik (University of Tartu,
Estonia), C. Guillermo Bueno (University of Tartu,
Estonia), and Jens Boy (Leibniz Universität Han-
nover, Germany). The key lectures covered topics
such as temperate rainforest plant biodiversity (A.G.
Gutiérrez and A. Premoli), EM fungal diversity pat-
terns (G. Palfner), the effects of AM fungi on soil
properties and on agriculture and bioremediation (F.
Borie – P. Cornejo), molecular community ecology
of AM fungi from local to global scales (M. Öpik),
plant mycorrhizal traits across different scales (C.G.
Bueno), and biogenic weathering by mycorrhiza (J.
Boy). Overall, there were over 70 participants for this
workshop, coming from eight countries (Argentina,
Brazil, Chile, Estonia, Germany, Spain, United King-
dom, and Uruguay), and 26 institutions (including
universities, research centers, companies, foundations
and public entities). Besides the seven key lectures,
14 oral presentations and 28 posters were presented
at the workshop with topics ranging from agriculture
and agroforestry — with a strong emphasis on wine
and wheat production, bioremediation, ecological res-
toration and land use, plant invasions and their my-
corrhizas, mycorrhizal biodiversity at different scales,
public management and outreach, and mycorrhizal
interactions with soil nutrients and with biogeochemi-
cal cycles. Research groups from Universidad Austral
de Chile (Chile), Universidad de La Frontera (Chile),
Universidad de Concepción (Chile), and Universidad
Nacional del Comahue (Argentina) contributed with
numerous presentations. Both experimental and de-
scriptive approaches were presented, using both mor-
phological and molecular methods to study AM, EM
and OM fungi.
As this workshop was the rst of its kind for the south-
ern part of South America and for South America
overall, it can be concluded that its aims were far sur-
passed since it became evident that South American
mycorrhizal research is more relevant than previously
though. Imitating mycorrhizal networks, which can
occupy hundreds of hectares, hopefully the mycorrhi-
zal researchers’ network facilitated by this workshop
will cover the South American continent and extend
abroad. Finally, we are conscious that there is still
much to do regarding mycorrhizal research in South
America; however this workshop was the rst inocu-
lum for the future of an incipient South American my-
corrhizal research network.
Acknowledgements
This workshop was organized by the Universidad
Austral de Chile, Universidad de La Frontera, Uni-
versidad de Concepción, Centro de Estudios Avan-
zados en Fruticultura -CEAF, and the EarthShape
Project (DFG). Special thanks to sponsoring institu-
tions: CONICYT, CONAF, Sociedad Chilena de la
Ciencia del Suelo, Sociedad de Botánica de Chile,
Sociedad de Ecología de Chile and the Global Soil
Biodiversity Initiative.