Compare Locations and Compare Years
CLIMEX uses minimal data sets and simple functions to describe the species' response to temperature and moisture, using Compare Locations or Compare Years options. A "Growth Index" (GI) describes the potential for growth of a population during the
favorable season, and four stress indices (Cold, Hot, Wet and Dry) describe the probability of the population surviving through the
unfavorable season. The GI and Stress Indices are combined into an "Ecoclimatic Index",
i.e., to give an overall measure of favorableness of the location or year for a species. The results can be presented as tables, graphs or maps.
CLIMEX includes a climate-matching function that can be used in the absence of any knowledge of the distribution of a species. The Match Climates option allows the user to directly compare the temperature, rainfall, rainfall pattern and relative humidity of a given location with any number of other locations. It provides a method of identifying sites with similar climates for targeting collection and release sites, or for assessing risks from exotic species. Weighting and masking functions allow the user to select variables for
modeling (e.g., temperature) or to choose particular months that need to be used in a comparison
(e.g., summer months in temperate zones).
The illustration shows a climatic comparison between Durban (South Africa) and Brisbane (Australia). CLIMEX compares rainfall, temperature and relative humidity patterns to produce a Match Index (0 - 1.0) that indicates similarity of climate.
The results are presented as a series of 'match indices' indicating the goodness of fit for the selected climatic variable. The function has been used most often to target collection or release sites for biological control agents, or to determine areas at risk from exotic species.