To answer that, you can combine a land cover dataset (e.g. GLOBCOVER: http://due.esrin.esa.int/page_globcover.php) with a climate dataset (e.g. after the Koeppen Geiger Classification: http://koeppen-geiger.vu-wien.ac.at/present.htm) in GIS. That should be uncomplicated, and then you exactly know what you get.

eiii.. not equipped with GIS software here but excellent idea, thanks

You can find information from different sources. I think that one of the most reputable is: http://www.elsevier.com/books/terrestrial-global-productivity/roy/978-0-12-505290-0. In this book, Saugier et al. estimate the area around 2.8 Million km2 (Mediterranean-type ecosystems).

mediterranean shrubland is found in Western North America, Borders of the Mediterranean Sea, Central Chile, Cape region of South Africa and Southwestern/southern Australia

according to the IPCC temperate shrubland covers areas greater than that (page 140):

https://www.ipcc.ch/pdf/assessment-report/.../WGIIAR5-Chap4_FGDall.pdf

I am not talking about Mediterranean ecosystems in the Mediterranean area. Temperate shrublands, Mediterranean-type ecosystems, Chaparral, Mediterranean shrublands, etc. are denominations for the same biome. The book consider the borders that you mention. Of course you can find other figures depending on the source.

Not sure I agree..

In chapter 14 the authors define Mediterranean-type ecosystems as those that occur in Mediterranean climate which "generally can be considered as a transition between dry tropical and temperate climates"."It is generally accepted that

these climates are characterized by a distinctive annual climatic sequence in which a

hot, dry summer alternates with a cool to cold, humid period lasting 5-10

months from fall through winter to spring. " The authors restrict the regions for occurence to those five I mentioned in my previous post.

The shrubland system I was studying was a temperate shrubland in Denmark- where the climate surely isn't tropical and we generally have plenty of rain.

Ok. Your definition was confuse for me (mediterranean shrubland is found in Western North America, Borders of the Mediterranean Sea, Central Chile, Cape region of South Africa and Southwestern/southern Australia).

In natural vegetation or global biome, shrubland refers to two major types of vegetation dominated by functional groups of shrub, they are Arctic shrub tundra and semi-arid shrub in temperate and sub-tropical regionals. In some classifications, shrubland also includes secondary (often human induced) ones located in moderate habitats. Several satellite based global land cover datasets are available to show spatial extent of shrublands, including those from MODIS, AVHRR, SPOT VGT, and MERIS. Simply Google these datasets.