Chapter 1 - Núria BONADA

Chapter 3
ecoregion; 4 in “Northern California Coastal redwood forest and steppe” and 3 in
“Southern California coastal chaparral woodland, coniferous forest and meadow”.
Localities in the Sierra Nevada are reaches with fast flowing waters, in forested basins,
medium slopes and substrates with boulders and cobbles. The riparian vegetation is
dominated by Alnus sp., Salix sp. (3 species), Populus sp. with some Pinus lambertiana and
Pseudotsuga menziesii from the adjacent coniferous forest. The algae Nostoc sp. is
abundant and frequently is present in symbiosis with Chironomidae larvae. In coastal
ranges, rivers have high slopes with coarse substrate except in the longest rivers (as San
Geronimo River) where gravels, sand and bedrock are important. Riparian vegetation is
composed by Quercus lobata, Alnus sp., Corylus cornuta, Sequoia sempervirens and
Umbellularia californica. Through the south and near the coast, sampled rivers are short,
small and steep. Substrates are similar to the ones in the northern coasts. The riparian
vegetation is composed by Quercus lobata, Platanus racemosa, Juglans hindsii, Populus
sp., Salix sp., Alnus sp., Corylus cornuta and Umbellularia californica. Rainfall accumulated
one year before sampling was 572.64 mm in an area near sampling sites (Napa valley).
Sites in South Africa
South African survey was performed in spring 2000. Sampling sites were located in three
different places (Figure 2): 3 in the Table Mountain ranges, 8 in the area of influence of the
Franschhoek and Drakenstein Mountains, and 1 in the low Palmiet close to the sea, in the
area called Kogelberg State Forest Reserve. Table Mountain sites have a high slope, with
boulders and cobbles dominant, whereas low slopes characterize the rest of sites. In all
cases, dominant vegetation is mountain fynbos, although near the river individuals of the
riparian shrubs Metrosideros angustifolia or Brabejum stellatifolium are present. In
headwaters, the macrophyte Isolepes sp. is abundant with mosses and Palmiet (Prionium
serranum). Rainfall accumulated one year before sampling was 569.2 mm in an area near
sampling sites (Cape Town).
Sites in SW Australia
A total of 9 sites in three catchments in the south of Perth were sampled in spring 1999:
Serpentine River, Drakes Brook and Brunswick River (Figure 2). They are located on the
Darling Plateau, where the karri forest is present providing a very forested basins by
several Eucaliptus species and with a shrubby undergrowth. Near the river, individuals of
Melaeuca sp. are present. Gravels, sand and silt, with bedrock and boulders scarce,
dominate the substrate of the rivers. Rainfall accumulated one year before sampling was
774.6 mm in an area near sampling sites (Perth).
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