. . oy 
Forest Development in the Adirondacks D0 
On Dry Sand On Wet Sand 
Juncus effusus Vaccinium augustifolium 
Iris versicolor Some introduced species, such as 
Ibidium cernwum strawberry and pearly everlasting 
Coptis trifolia 
Rubus hispidus 
Triadenum virginicum 
Spiraea latifolia 
Viola blanda 
Epilobiwm lineare 
Lysimachia terrestris 
Gentiana andrewsii 
Solidago uliginosa 
ELuthamia graminifolia 
Occasional leather leaf, Andromeda, 
cranberry and rarely a_ tuft .of 
sphagnum. 
Willows (several species including Salix bebbiana and dis- 
color) and alder (Alnus incana) have invaded the earlier asso- 
ciation and over many acres of the former forest area have 
established a shrub thicket. The shrubs are more dwarfed 
than where these species grow in wetter swamp-shrub associa- 
tions, forming low, compact clumps as shown in fig. 20. 
The occurrence of black spruce, tamarack, dwarf heath 
shrubs and even of occasional patches of sphagnum indicate 
that this portion of the sand plain is almost at the balancing 
point as between a bog sequence and a swamp sequence. It 
seems quite obvious that the deciding factor in such a sequence 
is simply the difference in the lie of the land; the slightly 
higher or at any rate better drained tending toward the em 
water marsh and swamp succession, the lowe lying or at any 
rate habitually ill drained terrain tending to favor sphagnum 
and its consequent peat bed with resulting bog succession. 
Here again it would seem that adjacent areas of sphagnum 
dominated associations (sphagnum-sedge, sphagnum-heath 
shrub or sphagnum-conifer forest) may develop a thickness of 
spongy sphagnum blanket which would enable the sphagnum 
to invade the marsh and swamp area and thus reduce it 
virtually to a bog condition. Possibly the former cover of 
balsam-swamp like forest was marked by the presence of 2 
sphagnum ground cover and it is not unlikely that the present 
willow-alder association will be succeeded by a mixed balsam 
