190 ALTERNATIONS IN TIMBER-GROWTH. 



The Rev. John Cronmbie Brown, in his report as Colonial Botanist 

 at the Cape of Good Hope for 18G5, p. 77, notices the destruction of 

 chestnut and walnut trees in different parts of that colony, and deems it 

 quite probable (although not directly proved), that the decay may have 

 been caused bj' water in excess at certain seasons of the year. He 

 does not regard this as inconsistent with the lact that great drought 

 occurs at other seasons. 



ALTERNATIONS IN TIMBER-GEOWTn. 



The track of a tornado through a forest, may sometimes be traced 

 long after the space has grown up with a new crop, by the difference of 

 timber. 



In 1845, a wide strip of forest was thus prostrated in Northern i^ew 

 York, the track extending from the settled regions of Jefferson County 

 to Lake Champlain. The timber was beech, maple, birch, ash, hemlock, 

 spruce, &c., and in its place we have now poplar, cherry, birch, and a 

 little beech and ironwood. 



In New England, the pine is often succeeded by the white birch; and in 

 New Jersey by the oak. The succession of oak by pine, and the reverse, 

 in the Southern States, was noticed long ago.^ The white-oak tim ber cut 

 oft' at Valley Forge, for fuel in the American camp, in 1777-78, was fol- 

 lowed by black oak, hickory, and chestnut. Poplars and other soft 

 woods are very often found coming up in pine districts that have been 

 ravaged by fire. We have noticed in Nebraska, ash, elm, and box-elder 

 following Cottonwood. In the natural starting of timber in the prairie 

 region of Illinois, when the stopping of fires allow, we often see a hazel 

 coppice; after a time the Crataegus, and finally the oaks, black walnuts, 

 and other timber. These growths are often quite aggressive on the 

 prairies. In Florida the black-jack oak usually takes the place of long- 

 l€af pine. 



This alteration of timber was noticed by Sir Alexander Mackenzie, in 

 an overland journey to the Arctic Ocean in 1789. When in the vicinity 

 of Slave Lake, he remarked : 



The banks are covered with largo qnantities of burned -wood, lying on the ground, 

 and young poplar trees that have sprung up since the fire that destroyed the larger 

 wood. It is a very curious and extraordinary circumstance, that land covered with 

 spruce piue, and white birch, when laid w^aste by fire, should subsequently produce 

 nothing but poplars, where none of that species of tree were previously to be found.* 



The elevated region around the headwaters of the Delaware, Alle- 

 gheny, and Genesee Rivers, when first brought to notice for settlement, 

 was covered with a heavy growth of hemlock {Abies canadensis), or with 

 forests of beech or sugar-maple ; but there is some reason to believe 

 that at an earlier period this region was covered with oak. In a letter 

 from John Adlum, of Havre de Grace, Md., to Judge Peters, of Phila- 

 delphia, September 16, 1807, he says : 



As to your query respecting a rotation or succession of forest trees, I am as well 

 satisfied of it, in my own mind, as if I had lived to see the whole change for centuries 

 back. I took the idea in the summer of 1788, when enrveying the lands south of the 

 great bend of Susquehanna, between that river and the Delaware, in what is called the 

 beech and sugar-maple country. In the course of my surveying, I traversed some places, 

 consisting of a few acres each, growing red and white oak trees of au enormous size, 

 none being less than sixteen feet in circumference five feet above the ground, and 

 generally from forty to fifty feet to the first branches. Some fow red oaks were 22 feet 



• Memoirs of Philadelphia Agricultural Soc. 1814, i, 41. 



» Foyaqe from Morttreal .... to the Frozen and Pacific Oceans in 1789 and 1793, 

 vol. 1, p. 227 



