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Orellana I.A.,Research Center y Extension Forestal Andino Patagonico | Raffaele E.,CONICET
New Zealand Journal of Forestry Science | Year: 2010

Invasive introduced species are among the most severe threats to biodiversity and the functioning of natural ecosystems. In this study we analysed whether Pseudotsuga menziesii (Mirb.) Franco is an invader species of two common types of native communities (native Austrocedrus chilensis (D.Don) Pic. Serm. & Bizzarri forests and mixed shrublands) of the subantarctic region of Argentina. We determined the density and the age structures of both P. menziesii and A. chilensis regeneration at the edges of P. menziesii plantations adjacent to native forests of A. chilensis and mixed shrublands. The invasion of P. menziesii was recorded in both types of native communities. In A. chilensis forest, the establishment of P. menziesii was significantly higher than in the shrublands. Also, P. menziesii showed a greater spread than A. chilensis inside and outside the plantations. The increased abundance of P. menziesii plantations, in addition to its invasive characteristics could lead to the replacement of native communities at a regional scale in the long or medium term. © 2010 New Zealand Forest Research Institute Limited, trading as Scion.


Rajchenberg M.,Research Center y Extension Forestal Andino Patagonico | Gorjn S.P.,Research Center y Extension Forestal Andino Patagonico | Pildain M.B.,Research Center y Extension Forestal Andino Patagonico | Pildain M.B.,CONICET
Australian Systematic Botany | Year: 2011

The aim of the present study was to characterise species of Antrodia s.l. from Patagonia, Argentina, and to determine their phylogenetic relationships by using morphological and cultural features as well as mating systems and ITS sequences. Phylogenetic trees generated from maximum-parsimony, neighbour-joining and Bayesian-inference analyses showed that the Argentinean collections were distributed inside the following three main clades: (1) 'Antrodia clade', with Antrodia ramentacea (Berk. Broome) Donk as a sole representative; (2) 'Amyloporia clade', including Amyloporia nothofaginea Rajchenb. Gorjn sp. nov. and A. stratosa (J.E.Wright J.R.Deschamps) Rajchenb., Gorjn Pildain comb. nov.; and (3) 'Fibroporia clade', with Fibroporia vaillantii (DC.) Parmasto and F. gossypium (Speg.) Parmasto. 'Amyloporia' and 'Antrodia clades' did not have strong molecular support; however, they were well defined with a polyphasic approach when other features such as the number of spore nuclei, mating systems and nuclear behaviour were added. Antrodia includes homothallic to bipolar species, with uni-or binucleate spores and normal nuclear behaviour. Amyloporia includes bipolar to tetrapolar species, with uninucleate spores and heterocytic nuclear behaviour. Fibroporia has strong molecular support and includes tetrapolar species, with uninucleate spores and normal nuclear behaviour. Amyloporia nothofaginea is described as a new species and two new combinations in Amyloporia are proposed. A key to the Antrodia s.l. species present in Patagonia is included. © 2011 CSIRO.


Greslebin A.G.,Research Center y Extension Forestal Andino Patagonico | Hansen E.M.,Oregon State University
Plant Pathology | Year: 2010

Field observations, isolations and pathogenicity tests were performed on Austrocedrus chilensis (Cupressaceae) trees to determine the pathogenicity of Phytophthora austrocedrae and its role in the aetiology of the cypress disease mal del ciprés (MDC) in Argentina. It was found that P. austrocedrae is a primary pathogen of A. chilensis. It was isolated from large necrotic lesions in the inner bark, and superficially in the sapwood, at the root collar and stem, in most of the MDC-affected stands surveyed along the range of A. chilensis in Argentina. The main symptom in naturally infected trees was a necrotic lesion extending from killed roots up to 1 m up the tree bole. Seedlings, saplings and adult trees were all susceptible to inoculation with P. austrocedrae. Under favourable experimental conditions (flooding), inoculated seedlings suffered massive mortality in less than a month. The importance of diseases caused by Phytophthora spp. in South American forests is discussed. © 2010 The Authors. Journal compilation © 2010 BSPP.


Austrocedrus chilensis is the most important natural conifer in the Patagonian Andes region of southern Argentina where there are 141,000 hectares of mainly pure stands. Fire is the main disturbance in the dynamics of these forests. The objective of the study was to analyze possible differences in chemical, physical and biological soil properties among unburned (NQ), partially burned (PQ) and completely burned (CQ) portions of two A. chilensis stands: one located near El Bolsón city (41° 59' 02'' S-71° 33' 20'' W) and the other one near Trevelin city (43° 12' 57'' S-71° 31' 15'' W). The stands were burned 21 months and five years before running the studies respectively. The following soil properties expected to influence forest recovery were measured: pH, electric conductivity (EC), organic carbon (C), total nitrogen (N), interchangeable potassium (K), calcium (Ca), magnesium (Mg), and nitrogen in the microorganisms (N-BM) in the upper 10 cm of soil. At El Bolsón study the PQ and CQ portions of the stand had higher pH and EC and less C, N, Mg and N-BM than the NQ portion. These changes may be related to the combustion of the organic matter. These differences were not registered at the Trevelin study; I speculate that at this site soil nutrient content could have been recovered because much more time elapsed between the occurrence of the fire and the installation of the study. It is desirable that after a forest fire the vegetation get reestablished as soon as possible to prevent nutrient loss and hasten the recovery of soils characteristics; this can be facilitated by planting A. chilensis.


Pildain M.B.,Research Center y Extension Forestal Andino Patagonico | Pildain M.B.,CONICET | Rajchenberg M.,Research Center y Extension Forestal Andino Patagonico | Rajchenberg M.,CONICET
Mycologia | Year: 2013

We investigated the phylogenetic relationships of Postia species from Patagonia with rDNA ITS and LSU sequences, together with morphological, cultural and biological features. All species in the genus were included in a "Postia clade" irrespective of whether their spores were thin-or thick-walled. This clade is characterized by tetrapolar mating, a normal nuclear behavior, metachromatic generative hyphae and absence of fiber hyphae in culture. One subclade merged the austral taxa P. pelliculosa and P. punctata, but otherwise no distinct relationships were found regarding spore shape, spore wall thickness and geographical distribution of taxa. The austral P. venata and the endemic P. carbophila, with thinwalled basidiospores, occupied variable positions in both analyses. Postia caesia from Patagonia grouped within the P. caesia species complex but on a separate branch. In contrast, P. rennyi and P. balsamea from Patagonia corresponded well with strains from other geographic areas. The two austral species in Ryvardenia, R. cretacea and R. campyla, characterized by nonmetachromatic hyphae, bipolar mating and an astatocoenocytic nuclear behavior, formed an independent subclade among the dimitic genera of the "Antrodia clade", far from other Postia taxa within which they had been placed previously, supporting their inclusion in a genus of their own. Postia carbophila grouped with other Postia species and not with Postia (Rhodonia) placenta as suggested previously on the basis of morphological comparisons. Instead, the latter species grouped with taxa in the dimitic genus Amyloporia with which it shares heterocytic nuclear behavior. A separation between specimens of Postia pelliculosa and Ryvardenia cretacea from either side of the Pacific (i.e. SE Australia/New Zealand and S Argentina/S Chile) suggests they could be considered different at the species level from a phylogenetic point of view. © 2013 by The Mycological Society of America.


In Patagonia Douglas-fir is grown to produce high quality timber; thus plantations should be pruned. To prune a stand, the proportion of green crown to be removed (pruning severity) and the number of lifts should be defined. The objectives of this research were to quantify the effect of pruning severity on tree growth and to select indicator variables to determine when to carry out pruning lifts. To achieve the first objective a trial was established on low, medium and highly productive sites. Pruning severities applied were heavy (65 % of the total tree height), intermediate (50 %), light (25 %) and control trees (no pruning). To accomplish the second objective the association between five easy to measure variables (diameter at breast height (DBH), total height, diameter over stubs height, pruning height, maximum diameter over stubs of previous pruning) and maximum diameter over stubs (DOS) was studied on 656 trees. Removing more than 25 % of the green crown progressively diminished subsequent tree growth. On highly productive sites, medium to high pruning severity did not reduce diameter growth as much as it did on low quality site, when carrying out second and third lifts. Diameter at breast height (DBH), and DBH along with previous lift height, was the more highly correlated variable with a maximum diameter over stubs.


Kuhar F.,Research Center y Extension Forestal Andino Patagonico | Papinutti L.,Laboratorio Of Micologia Experimental
Revista Argentina de Microbiologia | Year: 2014

Ganoderma lucidum (Curtis) P. Karst is a white rot fungus that is able to degrade the lignin component in wood. The ability of two strains of this species to produce the ligninolytic enzyme laccase was assessed. After the evaluation of induction with heavy metals and phenolic compounds, it was found that among the tested substances, copper and ferulic acid are the best laccase inducers. It was also observed that the two types of inducers (phenolic and metallic) produce different electrophoretic patterns of laccase activity. Optimized concentrations of inducers were obtained through a factorial design and the thermal stability of optimized supernatants was studied at a wide range of acidic pH. We found that the enzyme is more thermostable at higher pH values. © 2013 Asociación Argentina de Microbiología. Published by Elsevier España, S.L. All rights reserved.


Gorjon S.P.,Research Center y Extension Forestal Andino Patagonico | Hallenberg N.,Gothenburg University
Mycological Progress | Year: 2013

Gloeocystidiellum rajchenbergii, Hypochnicium patagonicum, Pteridomyces valdivianus, and Stereum greslebinii are described as new species from the Chilean Patagonia. An annotated checklist of corticioid fungi from Chile, listing 94 species with notes on distribution and ecology, scheduled for regular update, is available from http://corticioids.webs.com/checklists.htm. © 2012 German Mycological Society and Springer.


Gorjon S.P.,Research Center y Extension Forestal Andino Patagonico
Mycotaxon | Year: 2012

Dendrothele mangiferae, previously known only from the Mascarene Islands, is reported for the first time from Central America. It has been found in Costa Rica growing on bark of living Terminalia catappa. A full description, line drawing, and colour photos are provided. © 2012. Mycotaxon, Ltd.


Quinteros C.P.,Research Center y Extension Forestal Andino Patagonico | Bernal P.M.L.,CONICET | Gobbi M.E.,National University of Comahue | Bava J.O.,National University of Patagonia San Juan Bosco
Agroforestry Systems | Year: 2012

Seedling browsing by livestock has been indicated as major threat for forest sustainability use. Nothofagus pumilio forests are part of the livestock raising system in Patagonia, but because of the sparse understory cover, livestock graze mainly on flood meadows within the forest matrix. The complexity of the environment under study (forests and flood meadows) means that an adaptive predictor is needed to evaluate the intensity of resource use by livestock in order to assess its effect on the forest. Distance to flood meadows was evaluated as a predictor of the use intensity of the forest by livestock and its effect on the understory. The study was conducted at three sites in Chubut Province, Patagonia-Argentina. We established transects in the forest 320 m long, starting at the edge flood meadow-forest. In these transects, the livestock presence indicators (soil compaction, density of feces and trails) and composition of the understory were evaluated. Generalized Linear Model for repeated measures for longitudinal data were used. The indicators showed that distance is efficient for estimating forest use intensity by livestock. The understory varied with distance, the cover of exotic herbaceous was higher near the flood meadow. Far from the flood meadow, the cover was entirely composited of native species. The results support the use of distance to flood meadows as a tool for decision making in livestock and forest management in N. pumilio forests, and for further research on livestock effect on the forest. © 2011 Springer Science+Business Media B.V.

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