BROWN — PLANT LIFE OF NORTH CAROLINA LAKES. $31 



Where the canal has become filled with debris, the marginal and inter- 

 mediate zones extend as a narrow tongue far out into the lake. 



The migration of the plants from one zone into the ground occu- 

 pied by the next seems to be going on rapidly, but, owing partly to 

 a conflict with the plants present, the invaders probably do not 

 occupy at once all the ground which is capable of supporting them. 



The plants themselves are important factors in determining the 

 deposition of debris and the consequent local change in the character 

 of the soil. The plants of the marginal zone decay largely where 

 they fall. The thick stand keeps debris from being washed into this 

 zone and causes it to be deposited on the intermediate zone. The 

 plants of the intermediate zone also catch a good deal of debris. 

 Thus, as the marginal zone advances, new soil is prepared in the 

 intermediate. The plants of the central zone by their decay and by 

 catching debris also cause some change in that part of the lake, and 

 especially near the intermediate zone; but the plants of the central 

 zone, being submerged, must depend largely on that part of the debris 

 which settles to the bottom. 



It would seem probable that the marginal zone will finally extend 

 over the whole lake. It also seems probable that by the decay of the 

 plants in this zone the level of the ground will in time be raised 

 sufficiently to support a growth of Pinus serotina and Liquidambar 

 styracijlua. It is likely, however, that the grasses and sedges will 

 occupy the whole of the lake a long time before the trees make any 

 very great headway. 



ISLANDS AND TREES. 



In the water near the marginal or grass zone are a number of small 

 places where the soil comes nearly or quite to the surface of the 

 water. On these spots small trees of Acer rubrum are found, and 

 around these is generally a growth of Panicum hemitomon, or some- 

 times Sacciolepis striata. A few small specimens of Acer rubrum are 

 also found in the marginal zone. Where the canal banks near the 

 edge of the lake are somewhat higher than the surrounding ground, 

 there is found Acer rubrum, Liquidambar styracijlua, and Pinus 

 serotina. A few small specimens of Taxodium distichum also occur 

 in the lake. None of these trees are large enough or numerous 

 enough to shade the lake to any appreciable extent except for a short 

 distance along the northern canal at the eastern end. The trees in 

 the lake do not seem to be under favorable conditions. 



BANKS OF THE LAKE. 



Small plants of Pinus serotina and Liquidambar styracijlua are 

 invading the marginal zone where this grades into the shore. The 

 shores of the lake are generally marshy and covered with Pinus 



