Chapter 1 - Núria BONADA
Chapter 1 - Núria BONADA
Chapter 1 - Núria BONADA
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<strong>Chapter</strong> 3<br />
Plate 3. Characteristics of the mediterranean region in Chile.<br />
Chile<br />
Biotic river properties<br />
References<br />
High mountains<br />
Low mountains and hills<br />
Tablelands<br />
Plains<br />
Climatic features<br />
Location and latitude in Central Chile, 29-40ºS<br />
Extension of med-region around 70.000 km2 (1)<br />
Rank of precipitation from 25mm/y to 2100mm/y (2) with<br />
snow in the Andes ranges<br />
Months with highest rain between April and September<br />
Range of altitude between 0 to >5000m(3)<br />
Population of 11.000.000 inhabitans (4)<br />
Geology with metamorphosed sediments and igneous batholithic rocks in<br />
Andes; sediments in Central Valley; and metamorphosed and granites<br />
deposits in Coastal ranges (3).<br />
Landscape and topography composed by coastal ranges, central valley<br />
and west side of Andes ranges (3).Coastal plains scarce.<br />
Vegetation constituted by a semidesertic formation called “selva<br />
valdiviana”; an esclerofillous and evergreen trees and shrubs (called<br />
“matorral”); and woodlans with the deciduous Nothofagus sp, and the<br />
evergreen Drimys winteri.<br />
(4&5).<br />
Abiotic river properties<br />
Annual discharge peak in winter months, annually influenced by El Niño<br />
event (6)<br />
Physical and Chemical properties: oligotrophic, soft and neutral waters<br />
(7,8&9)<br />
River and stream typologies: streams from coastal ranges are short,<br />
steepe and small (called “quebradas”) whereas rivers from Andes ranges<br />
are longer, wider flowing straight to the sea (3&8).<br />
Riverbed substrate composed by boulders, cobbles and gravels in<br />
headwaters and sediments downstream (3)<br />
Periphyton community present in low abundances (10)<br />
Macroinvertebrate community poorly known compare with other med-regions. Several taxonomical works have<br />
been done in Plecoptera (11&12), Trichoptera (13) and Chironomidae (14) and ecological studies are increasing<br />
(15). The plecopterans Austronemouridae and Diamphipnoidae are endemic.<br />
Fish community highly diversified with 6 endemic families from Central Chile ( Trichomycterus areolatus, Percilia<br />
gillissi, Cauque mauleanum, Basilichthys australis, Cheirodon australe and Brachygalaxias bullocki),<br />
1 present in<br />
Central Chile and South of Argentina ( Percichthys trucha)<br />
and another shered with Argentina, New Zealand,<br />
Australia and Tasmania ( Galaxias maculatus). Several non-native species are present as Salmo trutta,<br />
Oncorhyncus mykiis, Ciprinus carpio and Gambusia affinis holbrooki)<br />
(8).<br />
Alloctonous material reach riverbed in summer except for woodland forests.<br />
Riparian Vegetation with evergreen and deciduous trees as Drimys winteri and Salix chilensis and several<br />
shrubs as Myrceugenella chequen and Aristotelia chilensis. Highly altered by non-native introductions of Pinus<br />
radiata (16)<br />
1-Grove & Rackman, 2001<br />
2-Emberger, 1930, 1955, 1971<br />
3-Thrower & Bradbury, 1973<br />
4-Dallman, 1998<br />
5-Hajek, 1991<br />
6-Waylen et al., 2000<br />
7-Hedin & Campos, 1985<br />
8-Campos, 1985<br />
9-Figueroa et al., 2000<br />
10-Soto & Campos, 1997<br />
11-Illies, 1964, 1965<br />
12-Benedetto, 1974<br />
13-Flint, 1974<br />
14-Brundi, 1966<br />
15-Figueroa & Araya, 2002<br />
16-Valdovinos, 2001<br />
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