38 BULLETIN" 272, U. S. DEPARTMENT OF AGRICULTURE. 



82 of the Bureau of Entomology, United States Department of Agri- 

 culture, entitled "Pinhole Injury to Girdled Cypress in the South 

 Atlantic and Gulf States;" also Circular 128 of the same bureau, 1 

 entitled, "Insect Injuries to Forest Products." 



Wind causes shake in the wood, and breaks down living trees when 

 badly weakened by decay. The majority of trees, especially the 

 veterans, reach their death through the combined agencies of the 

 pecky fungus, causing hollow hearts, and wind pressure. Strong 

 inshore gales combined with periodic high seas produce storm tides 

 which invade and submerge large areas not usually reached by salt 

 water. Unable to withstand exposure of this sort, the cypress in low 

 seacoast swamps is sometimes badly injured both by the saline 

 matter in solution and the mechanical force of high waves. Probably 

 this in great measure accounts for the large amount of defective 

 cypress sometimes seen along the coast, particularly on low advancing 

 river estuaries and deltas. The breaking of protecting barrier sand 

 reefs, the opening of tidal inlets, and other local changes in shore lines 

 sometimes cause a permanent invasion by the sea which injures or 

 kills the standing forest. 



EFFECT OP SUBMERGENCE. 



The effect of permanent submergence upon the subsequent growth 

 of cypress depends chiefly upon the rate at which it takes place and 

 the amount of deposition which results. The tree is apparently not 

 injured by deep submergence for periods of a few weeks only. In- 

 stances of rapid inundation by the sudden subsidence of land areas 

 are rather frequent over the comparatively recent land formations 

 where cypress finds its home. Shaler 2 cites a conspicuous instance 

 in the Mississippi basin of western Tennessee in which extensive tracts 

 of cypress land were flooded by subsidence accompanying the earth- 

 quake of 1811. Wherever the sinking brought the water permanently 

 to a considerable depth above the former level the trees died. About 

 1870 he observed that Reelfoot and other lakes were covered by the 

 stately columns of the trees thus killed during the lapse of over two- 

 thirds of a century. Near the outer margins the trees survived. In 

 artificial flooding, where the permanent water level is brought above 

 the knees, the trees have been reported by some observers to ba 

 injured or killed. 



1 The supply of Circular 82 is exhausted; Circular 128 is listed as available from the Superintendent of 

 Documents, Washington, D. C, price, 5 cents. Both are on file in all larger public libraries. 



2 Memoirs of Museum of Comparative Zoology, Harvard College, Vol. XVI, pp. 1-11. 



