372 BOTANICAL GAZETTE [NOVEMBER 
The forests of the mountain region of North Carolina are 
separable, according to Pinchot and Ashe, into three belts, lying 
at different elevations. These are as follows: (1) the forests of 
the lower mountains; (2) the forests of the higher mountains ; 
(3) the forests of the mountain summits. 
Zonally (climatically) the lower slopes of the mountains and 
valleys between are largely occupied by extensions of the Upper 
Austral (Carolinian) zone, but by far the greatest part of the 
surface of the mountain region is covered with an Alleghanian 
(Transition) flora. The higher mountains maintain Canadian 
trees, shrubs, and herbaceous plants, while along the crest of the 
highest mountains of this region, usually at an altitude of 6,000" 
(1,830™) and upward, a sparse Hudsonian flora is encountered. 
The green alder, Alnus alnobetula (allocated by edaphic condi- 
tions), Potentilla tridentata, Arenaria groenlandica, and Trise- 
tum subspicatum may be regarded as typical of this zone. 
Ecologically the following formations may be distinguished. 
Primarily these formations are determined by climatic condi- 
tions, and to give them ecologic significance they are named 
according to the character of the vegetation that determines 
them. The plant associations existing as part of these forma- 
tions are determined largely by light and soil-moisture (edaphic) 
conditions. Tentatively, the ecologic formations and associa- 
tions described in the following pages are these. 
1. Mixep Decipuous Forest Formation (2,000-5,000*, 610— 
1,525”). 
Castanea- piste Acer Association. Robinia hispida Association. 
Tsuga ciation. Aesculus-Acer-Betula Association. 
Ricdaindvon maximum Association. Acer-Sorbus-Viburnum Association. 
Lilium Associati Betula-Fagus Association. 
Plantago-A chile Aasciadson, Aesculus Assoctation. 
ubus Associ 
2. PKCD Forest Formation (5,000-6,700%, 1,525- 
2,040"). 
Sorbus-A cer-A eaten! ly defined). Rhododend atawbhtense Association. 
pce -Hlypnum A sociation. Carex-Poa Association. 
Po x Associatio: Picea-A bies-Prunus Association. 
race ¥ Ssociation, Viburnum-Vaccinium Association. 
e student is referred to a paper by KEARNEY (Science N. S. 12: 839, 831) 
ine the plants that characterize these zones. 
