I have fuelwood species preferences in the form of 1-3, Now, I want to make an overall preference index, How can I can I do this? I will be thankful for your suggestions and related literature.
You can opt the useability index (based on the use by community through indicators such as quantity; period of use in a year; accessibility (by distances or time)); and quality of fuelwood (based on wood quality such as calorific value and other indicators.). You may either get the value of calorific value in the literature or you can estimate.
Cline-Cole RA. (1984) Towards an understanding of man-firewood relations in Freetown (Sierra Leone). Geoforum 15: 583-594.
Where he looks at issues such as smoke and ash; as well as rainy and dry season performance. Variation also can occur depending on what people want to cook (some meals more smoke is preferable, etc..)
You have already received fairly good answers. One more attribute, I would like to add is " alternative uses". When a species has better alternative use other than ' fuel' , we should not opt such species for 'fuel/firewood' as it may not be cheaper or freely available. When we want to raise fuel wood plantations we should think about the most suited set of fuel wood species that can grow in that locality. Similarly when we want to use the available plant resources in an area having wide range of uses we have to make a comparative analysis and then arrive at the most suitable set. Thus,before making a 'choice' of suitable fuel wood species one has to look at the various issues involved in their totality. One can see that the preference varies over time & space.