Although urban and suburban soils are used for many purposes, some of them
relevant to agricultural and forest sciences, that these intensively manage
d and disturbed soils have not been extensively investigated up to now is s
uggested by the white areas representing most urban zones on soil survey ma
ps, Because urban soils are often developed on composite materials derived
from previous uses and exogenous sources, spatial heterogeneity is a typica
l feature. Their evolution is controlled almost exclusively by humans, who
impose very rapid transformation cycles compared with those occurring in le
ss disturbed areas. However, there is a continuum from the natural soils to
the extensively disturbed soils, and their basic functions are essentially
the same. As a result of their origin and uses, urban soils may contain po
llutants, the location, characteristics, and potential evolution of which m
ust be established clearly to ensure safe land uses. These soils can be inv
estigated with the traditional soil survey approach when the techniques are
adapted properly to the urban context. A multidisciplinary approach is nec
essary to ensure that urban soils are well understood in order to ensure th
eir optimum use.