A Restrictive Definition of Mediterranean Climates

Abstract

SummaryThree parameters have been chosen to define the mediterranean climate. They are: (1) Enough rainfall for successful dry farming in most years, but not enough to sustain either a dense coniferous or a mesophyllic broadleaf deciduous forest; (2) Mild winters without intense or prolonged cold weather; (3) At least 65 percent of precipitation falling in the winter half year (November through April in the northern hemisphere). Four sub-mediterranean climates that meet two of the three criteria are also defined and mapped. They are either too dry, too wet, too cold or without a sufficient winter rainfall concentration. The core mediterranean climate occupies a more limited area than in most classificatory schemes, but it does occur on all inhabited continents, and it does include most areas with characteristic mediterranean vegetation types. Other types of vegetation occur in it only in special edaphic situations. A somewhat more detailed map of California is presented showing the core mediterranean clim...