Shrubs

Shrubland (or matorral), maquis and garrigue are low formations, distinguished from one another by the height of their dominant layers. Shrubland and maquis occur on siliceous soil, while garrigue is found only on calcareous soil. They are generally degraded forms of closed or relatively closed forests, and although some do appear to be climax formations, they are most often the result of human activities (overgrazing, firewood collection, repeated burning, etc.). For example, when a cork oak forest in a humid or subhumid zone is degraded, it will turn into a maquis of tree heath (Erica arborea), Phillyrea sp., etc., which is replaced at a more advanced stage of degradation by a bushy formation of Pistacia lentiscus, Cistus sp., Retama sp., etc.; the final stage of degradation in this case is a heath of Cistus sp., Pteris sp. and Amplodesma.

These types of formation usually contain scattered trees (mainly holm oak, wild olive, etc.) among the shrubs and bushes. However, the floristic composition of these scrub formations varies widely and is thus hard to classify.

Steppes in the arid zones are also for the most part of secondary origin, resulting from depredations of Aleppo pine forests by humans and animals. They are low, broken formations with perennial grasses.

Although secondary steppes look the same as climax steppes, they are distinguished by the presence of such species as rosemary and Fumana.

last updated: Tuesday, January 13, 2004