VARIACION DEL HABITO Y HABITAT DE Nothofagus antarctica EN EL CENTRO SUR DE CHILE

1985 ◽  
Vol 6 (2) ◽  
pp. 55-73 ◽  
Author(s):  
C. Ramirez ◽  
M. Correa ◽  
H. Figueroa ◽  
J. San Martin
2014 ◽  
Vol 60 (6) ◽  
pp. 371-382 ◽  
Author(s):  
María Cecilia Mestre ◽  
Sonia Fontenla ◽  
Carlos A. Rosa

Environmental factors influencing the occurrence and community structure of soil yeasts in forests are not well studied. There are few studies dedicated to Southern Hemisphere soil yeasts populations and even fewer focused on temperate forests influenced by volcanic activity. The present work aimed to study the ecology of soil yeast communities from pristine forests influenced by different environmental factors (precipitation, physicochemical properties of soil, tree species, soil region, and season). The survey was performed in 4 northern Patagonian forests: 2 dominated by Nothofagus pumilio and 2 by Nothofagus antarctica. Yeast communities were described with ecological indices and species accumulation curves, and their association with environmental characteristics was assessed using multivariate analysis. Each forest site showed a particular arrangement of species as a result of environmental characteristics, such as dominant plant species, nutrient availability, and climatic characteristics. Cryptococcus podzolicus was most frequently isolated in nutrient-rich soils, Trichosporon porosum dominated cold mountain forests with low nutrient and water availability in soil, and capsulated yeasts such as Cryptococcus phenolicus dominated forest sites with low precipitation. The present work suggests that environmental factors affecting yeast communities may not be the current soil characteristics but the result of complex interactions of factors including natural disturbances like volcanic activity.


Author(s):  
I. J. Gamundí

Abstract A description is provided for Cyttaria darwinii. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. DISEASE: A highly evolved and highly specific obligate parasite causing often spectacular cankers only on branches of Nothofagus species. Fruitbodies only appear on the cankers; this fungus does not cause wood decay. HOSTS: Nothofagus antarctica, N. betuloides, N. dombeyi, N. pumilio, Nothofagus sp. (Fagaceae); more than 70% of all records are from N. antarctica and N. pumilio. GEOGRAPHICAL DISTRIBUTION: SOUTH AMERICA: Argentina (Chubut, Neuquén, Río Negro, Santa Cruz, Tierra del Fuego); Chile (Aisén, Los Lagos, Magallanes y Antártica Chilena, Bío-Bío, Maule). Highest recorded altitude: 1700 m. TRANSMISSION: Not known, but presumably infection is by wind-dispersed ascospores. The reasons postulated by INGOLD (1988) for evolution of the golf ball shape of fruitbodies of Cyttaria espinosae [IMI Descriptions No. 1593] are doubtless also valid for this species.


Author(s):  
I. J. Gamundí

Abstract A description is provided for Cyttaria hariotii. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. DISEASE: A highly evolved and highly specific obligate parasite causing often spectacular cankers only on branches of Nothofagus species. Fruitbodies only appear on the cankers; this fungus does not cause wood decay. HOSTS: Nothofagus antarctica, N. betuloides, N. dombeyi, N. nitida, N. pumilio, Nothofagus sp. (Fagaceae) [old fallen ascomata have also been recorded on soil, being blackish]. GEOGRAPHICAL DISTRIBUTION: SOUTH AMERICA: Argentina (Chubut, Neuquén, Río Negro, Tierra del Fuego); Chile (Aisén, La Araucanía, Los Lagos, Magallanes y Antártica Chilena, Bío-Bío, Maule). Highest recorded altitude: 1000 m. TRANSMISSION: Not known, but presumably infection is by wind-dispersed ascospores. The reasons postulated by INGOLD (1988) for evolution of the golf ball shape of fruitbodies of Cyttaria espinosae [IMI Descriptions No. 1593] are doubtless also valid for this species.


Author(s):  
Matias G. Goldenberg ◽  
Marcos Nacif ◽  
Facundo Oddi ◽  
Lucas Garibaldi

Nothofagus antarctica (G. Forst.) Oerst. stands of northern Patagonia (Argentina) have great potential to provide multiple ecosystem services. Nonetheless, the lack of basic information limits the application of silvicultural treatments to this forest type. This study reports the early response to three systematic strip thinning treatments (30, 50, and 70%) carried out during 2013 in a 30-year N. antarctica stand, where control plots (i.e. no thinning) were also established. Subplots were located within each plot. Basal diameters (BD) of all retained stems were measured in the non-vegetative season (winter) of 2016, 2017 and 2018, to calculate basal diameter annual increment (BDI), and stand volume growth. BDI ranged from 1.9 mm year-1 in the control plots to 2.7 mm year-1 at 70% thinning. Relative BDI also responded positively to thinning intensity. Stand volume growth decreased non-linearly with thinning intensity, from 3.36 m3 ha-1 year-1 in the control plots, and 0.71 m3 ha-1 year-1 when thinning was 70%. Smaller differences were observed between control plots, 30% thinning and 50% thinning. Our results show that Nothofagus antarctica forests, in the stem exclusion stage, respond to strip thinning. Thus, silviculture based on this management system could favor the development of retained trees without losing productivity if it remains under 50% intensity. This outcome represents an important incremental contribution to the design of silvicultural interventions in northern Patagonia.


2014 ◽  
Vol 60 (No. 8) ◽  
pp. 307-317 ◽  
Author(s):  
H. Ivancich ◽  
G.J. Martínez Pastur ◽  
M.V. Lencinas ◽  
J.M. Cellini ◽  
P.L. Peri

Tree growth is one of the main variables needed for forest management planning. The use of simple models containing traditional equations to describe tree growth is common. However, equations that incorporate different factors (e.g. site quality of the stands, crown classes of the trees, silvicultural treatments) may improve their accuracy in a wide range of stand conditions. The aim of this work was to compare the accuracy of tree diameter growth models using (i) a family of simple equations adjusted by stand site quality and crown class of trees, and (ii) <br /> a unique global equation including stand and individual tree variables. Samplings were conducted in 136 natural even-aged Nothofagus antarctica (Forster f.) Oersted stands in Southern Patagonia (Argentina) covering age (20&ndash;200 years), <br /> crown class and site quality gradients. The following diameter growth models were fitted: 16 simple equations using two independent variables (age and one equation for each stand site quality or crown class) based on Richards model, plus a unique global equation using three independent variables (age, stand site quality and crown class). Simple equations showed higher variability in their accuracy, explained between 54% and 92% of the data variation. The global model presented similar accuracy like the better equations of the simple growth models. The unification of the simple growth models into a unique global equation did not greatly improve the accuracy of estimations, but positively influenced the biological response of the model. Another advantage of the global equation is the simple use under a wide range of natural stand conditions. The proposed global model allows to explain the tree growth of N. antarctica trees along the natural studied gradients. &nbsp; &nbsp;


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