Watersheds and Mountain Vegetation in the Iberian Peninsula

Watersheds

a) The Watershed: This is the territory whose waters are discharged into a main river and its tributaries.

Features:

• They are separated by watersheds formed by the tops of the mountains that delimit them.
• Peninsular watersheds (North, Minho, Douro, Tagus, Guadiana, Guadalquivir, Pyrenees, Ebro, South, Jucar, and Segura).
• In the basin, the rivers circulate, forming a channel or a network from the tributaries and the main river.

Watershed Management

Joint catchments discharging into the sea itself. The cause is the inclination of the plateau to the west from the Iberian system.

• Rivers from the Cantabrian side: They are short because they are born in mountains near the coast. They are erosive, and there is a significant drop from their source to their mouth. However, the vegetation of these slopes protects the rivers of the Cantabrian. The rivers are plentiful and have a very regular regimen.
• Rivers from the Atlantic side: Long, born near the Mediterranean, and empty into the Atlantic. They have little erosive power. The flow is abundant because of many tributaries, but their regime is irregular.

Rivers of the Mediterranean dimension: Except for the Ebro, they are short, and because they are born in mountains near the sea, they violently erode deforested hillsides. Their throughput is low due to low rainfall, and their regime is very regular.

Mountain Vegetation

Vegetation floors are available in different configurations depending on the height and orientation:

A) Alpine or Pyrenean Mountain

There are 4 plant floors:

• The basement floor (oak and oak)
• Subalpine (natural conifers such as fir, black pine, and Scots pine)
• Alpine floor (has a short growing season and is snowy for 6 or 8 months)
• Nival floor (snow all year, much nonexistent vegetation, and moss likened only)

B) Rest of the Peninsular Mountains

• Baseline floor (occupied by the forest's own climate; in the Atlantic region, it is deciduous, and in the Mediterranean, evergreen in the lower areas and pine at higher elevations)
• Supraforestal floor (includes small shrubs)
• At the top (dominated by grassland in the Atlantic area and scrub in the Mediterranean)