standard errors are presented in Table 3. Biomass data of the
various tree components are given by treatments in Table 4.
Fertilization significantly increased the .bove-ground total bio-
mass of slash pine an average of 33%c over that of nonfertilized
trees. The application of fertilizer increased loblolly pine above-
ground biomass an average of only 20%. This is somewhat in
contrast to the effects of fertilizers on the heights of the two
species, as the per cent increase in height as a result of fertili-
zation was greater for loblolly than for slash pine. However,
more than twice as much biomass was produced by slash pine
as by loblolly on the Leon fine sand, regardless of the treatment.
 Response to fertilizers in terms of biomass production on
the various water table areas was similar to that observed for
height. Fertilizers resulted in a 81(K increase in slash pine bio-
mass in the fluctuating water table area, a 37%c increase in the
46-cm water table area, and 10 ; increase in the 92-cm water
table area. The greatest actual weight increase resulting from
fertilization was in bolewood production, and the increase in
foliage production was next greatest for both species. The aver-
age percentage increases resulting from fertilization for slash
pine components were 41%, 28%, 28%, and 27% for foliage,
bolewood, branches, and bolebark, respectively.
 The foliage weight from loblolly pine was only about half
that of slash pine, and the increase in foliage weight by fer-
tilizing this former species averaged 18%. On the other hand,
the percentage increase from fertilizers in loblolly bolewood pro-
duction was almost as great as that for slash pine, although
slash pine bolewood production was still almost twice that of
loblolly under all conditions in this experiment.
 The effect of water table levels on above-ground biomass was
highly significant (Tables 2, 4) and much greater than the effect
of fertilization. Controlling water table levels at 46 and 92 cm
increased slash pine biomass production over that on the fluc-
tuating water table by 124% and 122%, respectively. Loblolly
biomass increases were even greater than those of slash pine,
with 375% and 189% increases for 46 and 92-cm water table
levels, respectively. In terms of biomass production, loblolly
pine responded much more on a percentage basis to water table
control than did slash pine, while slash responded more to fer-
tilization than did loblolly. This may indicate that slash pine is
more sensitive to nutrient additions and loblolly more sensitive
to high water tables. Ecologically, slash pine is the dominant
pine species on these wet, poorly drained, low fertility Leon