Berberitzengebüsche und Nothofagus antarctica-wälder in nordwestpatagonien

Summary

In the region of the northwestern patagonian forests with Austrocedrus and Nothofagus, mainly within the territories of the Argentine National Parks “Lanin” and “Nahuel Haupí”, the shrubberies of Berberis and the forests and dwarf-forests (“chaparrales”) of Nothofagus antarctica have been studied according to the phytosociological method of Braun-Blanquet.

The forests and chaparrales of Nothofagus antarctica, together with most of the shrub-communities, were placed among the alliances Bacchari-Discarion articulatae and Nothofago-Berberidion. These were included within the order Berberi-Nothofagetalia antarcticae, that depends on the class Nothofagetea pumilionis-antarcticae. The Bacchari-Discarion seems to be limited to the territory of the forests of Austrocedrus chilensis. The communities of the Nothofago-Berberidion are supposed to occur allthrough the area of the Nothofagetea pumilionisantarcticae. Among them, there are the low forests of the Lomatio-and of the Ribesi-Nothofagetum antarcticae. Of the latter, also extensive chaparrales can be observed.

Of the shrubberies, among others, were traced the Mutisio-Berberidetum darwinii and the Ribesi-Berberidetum parodii.

The Lomatio-Nothofagetum and the Mutisio-Berberidetum seem to be confined to the territory of the forests of Nothofagus dombeyi, especially those of the Austrocedro-Nothofagetum, in the southern part of the region. The Ribesi-Nothofagetum and the Ribesi-Berberidetum are mainly found in the northern part of the zone, where the forests are distinguished by the presence of Nothofagus obliqua and N. procera. But they also extend southward and towards the east, especially the Ribesi-Nothofagetum in its form of a chaparral, and the Ribesi-Berberidetum, subass. of Escallonia virgata, on soils with a groundwater table near the surface.

The shrubberies of the Nothofago-Berberidion are anthropogenetic permanent communities; they are replacing not only the low forests of Nothofagus antarctica, to which they floristically are very akin, but also forests of N. dombeyi, N. obliqua and N. procera.

From the communities of the Berberi-Nothofagetalia antarcticae, the shrubs Berberis buxifolia and B. darwinii, though with less abundancy and less constancy, are passing over to the hedges and shrubberies of the Berberidion buxifoliae, that Oberdorfer (1960) described from Chile as an element of the Wintero-Nothofagetea. It might be convenient to change the name “Berberidion buxifoliae” into “Aristotelion”, which would be a more characteristical one, as can be judged now.

On the sandy and stony shores of the lakes as well as on the river banks grow communities of shrubs as Escallonia rubra, Baccharis obovata, Berberis parodii, Fuchsia magellanica, etc. The situation of these shrubberies in the system of plant-communities is not yet certain; as a provisional arrangement, the Escallonion rubrae has been established. Similar shrubberies with Escallonia and Fuchsia are quoted from the territory of the Nothofago-Winterion in South-hern Chile.

Besides of a description of the scenery and natural order of landscape, some comparaisons with European vegetation and observations on environment and syngenetics of the studied plant-communities are made.

The name of the plant-communities, which are compared in Table I, can be found in the text by means of the subheadings; on the right hand of them the numbers of the corresponding tables and columns are indicated.

Resumen

En la zona de los bosques de Austrocedrus y Nothofagus en los Parques Nacionales Lanín y Nahuel Huapí, Argentina, se realizó un estudio fitosociológico de matorrales de Berberis y de bosques y chaparrales de Nothofagus antarctica.

Los bosques y chaparrales de Nothofagus antarctica, en conjunto con la mayor parte de las comunidades arbustosas, se distribuyeron en las alianzas Bacchari-Discarion articulataey Nothofago-Berberidion, las que se agrupan dentro del orden Berberi-Nothofagetalia antarcticae, dependiente de la clase Nothofagetea pumilionis-antarcticae. El Bacchari-Discarion parece limitado al territorio de los bosques de Austrocedrus chilensis; las comunidades del Nothofago-Berberidion probablemente se hallan en toda el área de los Nothofagetea pumilionis-antarcticae. Entre ellas figuran los bosques bajos del Lomatio- y del Ribesi-Nothofagetum antarcticae; del segundo además se observan extensos chaparrales. Entre los matorrales se describen, entre otros, el Mutisio-Berberidetum darwinii y el Ribesi-Berberidetum parodii.

El Lomatio-Nothofagetum y el Mutisio-Berberidetum se limitan, según parece, al territorio de los bosques de Nothofagus dombeyi, especialmente del Austrocedro-Nothofagetum, de la parte Sur de la zona. El Ribesi-Nothofagetum y el Ribesi-Berberidetum parodii se encuentran principalmente en el área de los bosques con Nothofagus obliqua y N. procera en la parte Norte, pero se extienden también al Sur y al Este: el Ribesi-Nothofagetum en forma de chaparrales, y en suelos con napa freática alta el Ribesi-Berberidetum parodii, Subass. de Escallonia virgata.

Los matorrales del Nothofago-Berberidion son communidades permanentes antropogéneas que sustituyen no solamente a bosquecillos de Nothofagus antarctica, con los cuales tienen mas afinidad florística, sino también a bosques de Nothofagus dombeyi, N. obliqua y N. procera.

Berberis buxifolia y B. darwinii se extienden de los Berberi-Nothofagetalia, aunque con menor abundancia y presencia, a los setos y matorrales del Berberidion buxifoliae, que Oberdorfer (1960) describió para el Sur de Chile, y que forman parte de los Wintero-Nothofagetea. Se considera conveniente cambiar el nombre “Berberidion buxifoliae” por “Aristotelion”.

Las playas arenoso-pedregosas de ríos y lagos hospedan, principalmente en la parte occidental de la zona, comunidades de arbustos como Escallonia rubra, Baccharis obovata, Berberis parodii, etc. La ubicación de estos matorrales en el sistema de las comunidades vegetales queda todavía incierta; provisoriamente se establece el Escallonion rubrae. Matorrales afines de Escallonia y Fuchsia se indican para el territorio del Nothofago-Winterion en el Sur de Chile. Además de una descripción del paisaje y comparaciones con comunidades vegetales de Europa Central, se dan a conocer algunos resultados de observaciones ambientales y singenéticas.

Los nombres de las comunidades vegetales que se comparan en la Tabla I pueden encontrarse en el texto alemán mediante los subtitulos, tras los cuales se indican los números de las tablas y columnas correspondientes.