Iberian Ecology: Primates, Past Climates & Vegetation

Posted on Apr 5, 2025 in Geography

A Primate in an Oak Grove

  1. The study of the geographical distribution of plants and animals concludes that Europe is generally not a favorable continent for primates, except for our species, Homo sapiens, for which all continents are suitable.
  2. The origin of hominids is in Africa; our arrival in Europe is relatively recent.
  3. Humans migrating from Africa to Europe had to adapt to local ecosystems, which were very different:
    1. First, the primate ancestor that later came to Europe stopped being exclusively arboreal (tree-dwelling) and learned to live in a non-tropical climate.
    2. If Homo sapiens did not exist, it would be impossible to find a primate in a Spanish oak grove, pine forest, or beech forest.

The Lost World: Past Iberian Climates

  1. Before the Quaternary period, the Earth’s climate was warmer, and humidity was higher. Consequently, the vegetation of the Iberian Peninsula was different from the current, more tropical era. In the Miocene and Pliocene, temperate forests in Iberia included oak, ash, hazel, and alder, but there were also large forests with many species that have no counterparts in the region today.

Ice Age Iberia: Glaciation Effects

  1. During the Last Glacial Maximum (21,000-17,000 years ago), the climate was very harsh throughout Europe. Sea level dropped by about 120 meters compared to the current level. The mean annual temperature in the Iberian Peninsula was 10°C – 12°C lower. This is comparable to the peninsula moving 2,000 km north or rising more than a kilometer in altitude. Above 700 meters altitude, the average temperature likely did not exceed 3°C. The summits of major peninsular mountains were covered by snow.
  2. Extensive mountain glaciers existed in the Pyrenees, Central System, Sierra Nevada, Galaico-Leonesas mountains, Cantabrian Mountains, and Iberian System, with lengths exceeding 30 km and ice thicknesses sometimes over 400 m. The Sierra Nevada glaciation was the southernmost in Europe.
  3. Neanderthals and their ancestors likely never experienced widespread glaciers on the Peninsula, except perhaps in the Pyrenees. The climate was not as cold as that endured later by Cro-Magnon humans. Whenever ice dominated Europe, the landscape changed dramatically. Mosses, lichens, and herbs replaced trees. These climatic conditions, known as periglacial, featured permanently frozen ground (permafrost) many meters deep. In the southern part of the continent, deciduous forests of oak, beech, and others persisted, with oaks favoring warmer coastal areas.
  4. During the Late Pleistocene, mixed forests of deciduous oaks and cork trees expanded across the mainland. Ultimately, Iberia became almost entirely forested.

Current Spanish Vegetation Distribution

  1. Almost the entire surface of the Iberian Peninsula is potentially forestland. It was covered almost completely with trees before humans, using axes and fire, cleared land for crops, livestock, and timber exploitation. Early humans hunted, gathered plant products, and formed small, dispersed groups, living in relative harmony with the environment. The vegetation of ancient Hispania is divided between two major floristic regions:
    1. The Euro-Siberian region: Occupies the Basque-Cantabrian strip, Galicia, northern Portugal, and the Pyrenees.
    2. The Mediterranean region: Accounts for the rest of the Hispanic plant cover.
  2. This division of Iberian vegetation into two regions (a dry and a wet one) is not entirely drastic:
    1. Oaks can be seen in many parts of the Cantabrian coast, both in drier sites and near the sea.
    2. Deciduous forests exist in the Mediterranean region where there is sufficient moisture throughout the year.
    3. It might be more realistic to divide Iberian vegetation into: a zone influenced by the Atlantic, another Mediterranean zone, and extensive interior regions with intermediate (sub-Mediterranean or sub-Atlantic) characteristics.
  3. This ecological diversity allowed prehistoric hunters to find, within a small area, animals characteristic of rocky terrain and mountain peaks alongside inhabitants of forests and meadows. This variety of habitats within a limited space, characteristic of Iberian nature, means researchers cannot definitively assign a fossil assemblage from a single site to a single environment. Herbivore remains often come from different communities and may have been brought together by predators or humans.