There are two issues with wood in humid conditions;
1) As it absorbs water and then dries out it swells and contracts changing shape - dimensional stability is a measure of how much each type of wood changes shape in this way. Movement can be in both radial and tangential directions (thickness and width). If you are using wood for window frames or door frames if it changes shape too much you will have issues opening and closing and with maintaining a good seal. So for these types of applications, you need to choose a wood that has good dimensional stability.
2) Rot. Mould, fungus and bacteria like humidity. So if your wood is in humid conditions you need a species that is resistant to attack by microorganisms. This often means you need to use a treated wood or apply a treatment. You can do a Google search to find out relative decay rates of specific species - I have attached an example as a jpg.