This map is designed to help golf course developers and managers around the world to achieve best practices in sustainable course management. It shows the global distribution of climate zones that are suitable for the main types of turfgrass - cool season species and warm season species. The "transition zone" is the climate zone in which neither cool nor warm season species are ideally suited.
How was the map made?
The map was made using Geographical Information Systems (GIS) modelling. GIS is a powerful way of capturing, storing, analyzing, and displaying geographically referenced information - data that is identified according to location.
The main determinant of turfgrass suitability is soil temperature, so making the map involved modelling GIS climate data to produce the soil temperature during the growing season for grass across the whole world. The climate data used came from the United Nations Intergovernmental Planet on Climate Change (IPCC), which collates climate data for use in environmental modelling. The dataset contains average climate measurements over a 10 year period (1981-1990) and is at a 0.5 degree resolution. This means that the calculations were made on a world map divided up into cells that are approximately 50km by 50km.
A computer model was created to work out the most suitable type of turfgrass for each cell. The model first identified the growing season for grass, then calculated the soil temperature over this period. The soil temperature data was then used to decide which type of grass species would be most suitable in each location. The altitude of each cell was also taken into account.
The map was created to give a global overview of the distribution of climate zones suitable to the main types of turfgrass species. In constructing the map, soil temperature was the only variable taken into account. Other variables, such as precipitation and soil type, also affect the suitability of different turfgrass species and we hope to take these into account in future editions.
Because the information used to create the map is averaged over 50km cells, it cannot take into account very local variations in climate. However, we feel it is an accurate representation of the general conditions in each area.
Further information<br>Mitchell, T.D. and Jones, P.D., 2005. An improved method of constructing a database of monthly climate observations and associated high-resolution grids. International Journal of Climatology, 25, 693-712.