Data/hora: 21/06/2024 16:25:12

Biblioteca(s): 	Embrapa Pantanal.	
Data corrente: 	25/02/1999	
Data da última atualização: 	01/03/2010	
Autoria: 	MORELLO, J. H.; TOLEDO, C. S.	
Título: 	El bosque chaqueno. I. Paisaje primitivo, paisaje natural y paisaje cultural en el Oriente de Salta.	
Ano de publicação: 	1959	
Fonte/Imprenta: 	Revista Agronomica del Noroeste Argentino, v.3, n.1/2, p.5-81, 1959.	
Idioma: 	Espanhol	
Conteúdo: 	The authors examine the changes caused by extensive livestock breeding in the woods and grasslands of the Chaco. The primitive landscape was formed by wood and grasslands. The former were principally of two types: 
a) Quebracho stands of Schinopsis quebracho-colorado and Aspidosperma quebracho-blanco.
b) Palosanto stands of Bulnesia sarmientoi and Aspidosperma quebracho-blanco or Bulnesia sarmientoi and Aspidosperma triternatum.
The grasslands were formed by Pennisetum frutescens, Elionurus tripsacoides, Trichloris crinita, trichloris pluriflora, Setaria argentina, Gouinia paraguayensis and Gouinia latifolia.
In the savannahs of the uplands there is always an indication of fire (ashes on the soil, boiled earth, carbonized bases of standing trunks, fire scars on old logs) so that the authors believe that the savannhas are pyrogenic, and that the fires provoked by lightning have been more important than those caused by man. In the first quarter of this century animal husbandry was limited to the grasslands, the first noteworthy change took place through transformation of the grasslands into shrub communities of Acacia, Mimosa, Mimozyganthus and Celtis. Once the pastures were exhausted, the cattle starded to feed in the interior of the wooded areas whereby it produced a large number of floristic and phytosociological changes:
a) Propagation of species heretofore unknown in virgin forest such as Larrea divaricata, Cassia aphylla. 
b) Invasion by species largely limited to the major drainage bottoms, such as Proposis nigra, Acacia aroma, Acacia caven, Acacia macracantha, geoffroea decorticans and Proposis ruscifolia. 
c) Invasion by large Cactaceae of the arborescent type, especially Opuntia quimilo.
d) Formation of anthropogenic communities such as: 
1. "Algarrobal negro" (mesquite like community): consorciation of Proposis nigra.
2. "Quebracho blanco" stands: consorciation of Aspidosperma quebracho-blanco.
3. "Vinalar" (mesquite like community): consorciation of Proposis ruscifolia.
4. "Bosque peri-represa" (forest around a watering-place for cattle): association of Proposis alba, Proposis nigra, Celtis spinosa, Parkinsonia aculeta and Geoffroea decorticans.
5. Brush of acacia, Mimosa, Mimozyganthus y Celtis.
6. "Jarillar" (creosote bush community): consorciation of Larrea divaricata or association of Larrea divaricata and Cassia aphylla.
7. Brush of Acacia aroma and Acacia caven.
8. Vegetation around the cattle and goats ranches.
These communities induced by man are formed by elements which have their origin in three environments:
1. In the phytogeographic province known as "Monte" where the yearly rainfall is below 200 mm, while in the region under consideration (part of the phytogeographic province of the Chaco) it reaches 450 to 500 mm.
2. In the alkaline flats (salty areas) of the Chaco.
3. In the swamps, and near permanent rivers of the Chaco.
Each of these communities is studied in detail. Climate, overgrazing and fire were evaluated as factors that may have, contributed to the floristic and phytosociological changes. Grazing by livestock (cattle and goats) is of paramount importance in the vegetational changes in part because of seed dissemination, in part because of overgrazing and removal of potential fuel for range fires. The upland savannahs were maintained as such by fire before the introduction of livestock. Finally the effects of cattle and goats is studied separately: their effect upon the valuable forest seedlings and seed and fruit dispersal is examined, and the diet of these animal discussed. 	
Palavras-Chave: 	Cultura primitiva; Cultural; Eastern Salta; Landscape; Natural; Oriente de salta; Paisagem natural; Paisagem primitiva; Primitive.	
Thesaurus Nal: 	Argentina; cultural landscape.	
Categoria do assunto: 	--	
Registro original: 	Embrapa Pantanal (CPAP)	
Exemplares: 	CPAP - (36726-1) - ADD - SP - -- - SP3611 -  - 3611 - DIS
CPAP - (37463-1) - ADD - SP - -- - SP4124 -  - 4124 - DIS