46 BOTANICAL GAZETTE [january 



Ulmus fulva Michx., Fraxinus nigra Marsh., and Betula alba L. 

 var. papyrifera Spach. The herbage is of such species as Aralia 

 racemosa L., A. nudicaulis L., Dactylis glomerata L., Panicum spp., 

 Ranunculus abortivus L., Solidago caesia L., S. canadensis L., 

 Osmorhiza Claytoni Clarke, and Geranium Bicknelli Britton. 

 Rubus idaeus L. often plays a large part if the clearing is not too 

 small and the seeds are introduced at a time when room is available. 



Secondary scrub and interference 



Terminology suggested (3, pp. 145-166) 



1. Revegetation 



a) Primary: original or primary vegetation of the area. 



b) Secondary: vegetation coming up after removal of primary society. 



(1) Repetitive: secondary succession following course of primary. 



(2) Nonrepetitive: not following primary. 



2. Degree of interference 



a) Partial: few adult trees felled. 



b) Incomplete : all adult trees felled. 



c) Complete : all but herbage removed. 



d) Destructive: all vegetation removed; includes areas where refuse is 

 burned off. 



3. Recurrence of interference 



a) Simple: occurs once; area left alone thereafter. 



b) Repeated: interim for partial recovery allowed. 



c) Continuous: repeated at short intervals so that no recovery is allowed. 



4. Terrain: left clean, dirty (refuse left), or burned 



5. Successional phases 



a) Regressive: reversion to an earlier stage, or "lower" floristic type. 



b) Delayed: same stage but individuals of an earlier age. 



c) Static: approximately same stage and life age. 



d) Progressive : succession hastened. 



6. Ecological state 



a) Stage: as used for some point in succession of species. 



b) Age: as used for some point in succession of individuals. 



Xerarch treeless societies 



The upland herb and shrub floras appear to show five secondary 

 societies. > 



Fireweed society. — Most of its species are not native. In 

 clearings, particularly those resulting from destructive interference, 

 with dirty or burned terrain, strongly regressive changes occur, 



