[January BOTANICAL GAZETTE 46 



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

 var. papyri/era Spach. The herbage is of such species as Aralia 

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

 Ranunculus abortkms 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. Revegctation 



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



/>) 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 



(7) 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, 



