Distribution Maps

The TDWG world geographical scheme for recording plant distributions (Brummitt 2001) is the system used in the GrassWorld Delta database to record the geographical distribution of species. The TDWG system has up to four levels of precision from the continental level (level 1), through regional level (level 2) to geographic units (level 3) and subunits (level 4). There are 9 continental groups, 52 geographic regions and 388 geographic units (Brummitt 2001). Of the geographic units, 71 are further divided into level 4 subunits in situations where a finer division of large countries, such as China, India, Brazil, Argentina, Chile and Mexico, leads to a more precise distribution of grasses. A few other countries such as the DRC (formerly Zaire) and Australia should be further subdivided in TDWG to provide better precision for distribution in a global context. An example of the present imbalance has the Vatican (1 sq km) and Western Australia (2.5 million sq.km) as the smallest biogeographic areas for those respective regions of Europe and Australia. For Australia the larger states of Western Australia, Northern Territory, South Australia, Queensland and New South Wales have been divided into smaller regions in the Delta database and are presented in the Scratchpad species descriptions. However they are not able to be represented on the Scratchpad generated maps, which strictly follow the TDWG categories. More precise information of the Australian distribution can be accessed through the AusGrass2 Scratchpad (http://ausgrass2.myspecies.info/).

Distribution Maps are now located under World Grasses.

Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith