In all forms of magick, the universe and everything in it are said to be made up of four elements: Air, Fire, Water, Earth. The element of Spirit rules the center as a balance. In dragon magick, specific dragons rule these elements and help to create through their powers.
Fire and Air are traditionally positive (male) energies; Water and Earth are traditionally negative (female) energies. Male and female dragons may appear in the elemental directions in the traditional places, or they may at times appear female in male directions and vice versa. This leads one to surmise that dragons may be androgynous creatures. These four elements correspond to the four directions, the four quarters of the universe, the four winds, and the four quarters of the magickal circle.
Reference Material: D. J. Conway's "Dancing With Dragons"