Ask Mr. Smarty Plants

Hurricane Ike was truly a disaster, and this is the second question we have received from Pearland on tree replacements. See this previous answer, which covers types of oaks recommended for replacement by an HOA. We mention this because we're curious as to why your oak tree died. You didn't say what oak you have, but you'll notice in the answer we linked you to that several oaks are very susceptible to oak wilt.  We couldn't find any substantiation to the idea that you could not plant another oak where one had already grown. Oaks do provide themselves with some protection from other plants encroaching on their territory, defending root space, nutrient availability and water, as do many other plants; see this previous answer on allelopathy of oaks. But, if your tree died of some disease, if for no other reason, we would recommend you not replace it with another oak, at least not one susceptible to oak wilt. 

We would recommend that you get a trained arborist to assist you with this. In the first place, removal of the dead oak is going to be necessary, including checking for disease. In the second place, planting a 45 gallon tree is a job for specialized equipment and knowledgeable personnel. If your HOA did not give you a list of replacement trees from which to choose, we have three that we would recommend, including a magnolia, since you indicated you were interested in planting one.

Magnolia grandiflora (southern magnolia) - relatively fast-growing, difficult to grow anything under it because of deep shade, evergreen

Quercus macrocarpa (bur oak) resistant to oak wilt, drought resistant, long-lived, relatively fast-growing, resistant to air pollution

Ulmus crassifolia (cedar elm) - hardy, drought resistant, adaptable to broad range of soil types

Magnolia grandiflora

Quercus macrocarpa

Quercus macrocarpa

Ulmus crassifolia