ll a itl 
= a a ee 
I EEE EE EE IE EE 
1899] DUNE FLORAS OF LAKE MICHIGAN 369 
and terraces, embryonic heaths often have Hudsonia tomentosa, 
Andropogon scoparius, and Campanula rotundifolia arctica in addi- 
tion to the above. 
At the center of fig. 6 there is shown a heath developing on 
a substratum of embryonic dunes ; the bearberry has already 
covered a large portion of this area with a low heath carpet. 
fig, 24 shows the development of a heath on a fossil beach. In 
the foreground is a typical fossil beach flora, consisting of scat- 
ered grasses, sand cherries, etc. The small scattered tufts are 
Hudsonia. At the center is a low Ammophila dune, while back 
of this are patches of embryonic heath, composed of the bear- 
berry and the procumbent juniper. Along the edge of the 
forest the heath forms a continuous carpet. Fig. 25 shows a 
Ypical juniper heath when fully developed. At the left back- 
sound the heath is younger and still made up of disconnected 
patches, Fig. 26 shows the formation of a Jumiperus communis 
th in a pasture. Since this latter species is more or less 
“ect, while the.bearberry and procumbent juniper are creepers, 
the aspect of the heath shown in fig. 26 is very different from 
those shown in Jigs. 6 and 24. 
b. The coniferous forests —Whatever the origin of the heath, it 
farely a climax type along the Lake Michigan shore. It 
almost uniformly develops into a coniferous forest sooner OF 
liter. The most conspicuous and extensive forests of this type 
“eon the lakeward slopes, at the summit of these slopes, or at 
the summit of the taller inland dunes. These forests, like the 
“ath, become more abundant and the growth more luxuriant as 
ome Passes northward along the lake shore. 
The development of a forest from a heath is easy to under- 
heey and can be observed at almost all points. The ae 
“Sttation is dense enough to prevent the tearing up of ee 
Y the Wind, but not too dense for seedlings of various trees to 
oo The dense tangle of junipers and_ bearberries ree 
€ soil js peculiarly well fitted to protect the trees whl 
‘mall and tend i ll and scattered trees 
c er. In a very short time sma eee 
°Mspicuous on the heath. The transforma 
is 
St 
