"Big Woods", located about a mile and a half southeast of the Brown- 

 field Woods, has been found to contain 31 tree species in the 51 acres 

 of semi-virgin forest. ( McDougall (2)*.) In our survey of the Brown- 

 field Woods all trees having a diameter of three inches or more were 

 tabulated, but the specific headings were based upon commercial divi- 

 sions rather than true botanical differences. Thus all ashes were listed 

 under ash. all white oaks under the single heading of white oak, the 

 black oak group under red oak, etc. Listed in this manner, there were 

 seventeen different groups of species, but a complete botanical survey 

 would doubtless reveal nearly double this number of tree species. 



A unique feature of Brownfield Woods is the splendid dimensions 

 of occasional trees. The Lower Wabash in former years held huge trees, 

 the largest broad-leaves on the continent. A few huge sycamores yet 

 stand, stag-headed and isolated, too enormous for our energetic axemen 

 to fell : but of those giants which stood as neighbors — magnificent tulips, 

 pecans, sweet gums, and oaks — we have only records. Yet in this ex- 

 tremely outlying fragment of 56 acres of the Upper Wabash forest there 

 are 36 trees attaining a diameter from three to five feet at a point ±y 2 

 feet from the ground. There probably does not exist in Illinois, or on 

 our continent even, another upland area with such a variety of great 

 hardwood trees. Included among these thirty-six monarchs are ashes, 

 elms, and oaks. One of the largest trees in the woods is the bur oak 

 already mentioned, with a diameter of 65 inches and a height of 101 

 feet; and another, with a diameter of 15 inches, has a height of 112 

 feet. These are not large trees as contrasted with those which have dis- 

 appeared, yet we have record of but one larger living oak in the state, 

 and no record whatever of so many large oak, elm, and ash in a single 

 wood-lot. 



The actual number of trees present per acre (115) is low as com- 

 pared with the average of the all-virgin upland stands studied in the 

 state (116) ; but the average diameter for the Brownfield trees is 12.7 

 inches as against 10.9 inches in the virgin upland stands in general. The 

 loss is in the low diameter classes. An examination of the last column 

 on page 9, which shows the total of all species for each diameter, 

 brings out the fact that there are fewer 3- and 1-inch trees than in either 

 5, 6, 7, 8, 9, or 10-inch classes. In a normal virgin forest by far the 

 greater number of trees are always in the smaller-diameter classes. 

 Brownfield Woods, in its larger-diameter class of trees, conforms to this 

 rule, their number increasing with reasonable regularity as the diameters 

 diminish, but from the 6-inch class down to the 3-inch the number of 

 trees rapidly diminishes. There are two possible explanations : either 

 (1) for the past forty years the use of the woods by man and cattle has 

 destroyed the reproduction, and if continued will ultimately result in the 

 complete destruction of the woods; or (2) it is possible that the forest 

 was more open than now some forty or fifty years ago, offering light 

 conditions which favored the establishment of seedlings, and that fires or 

 grazing prevented the establishment of seedlings for a time, after which 

 the somewhat open forest was not burned or grazed. Thus there would 

 become established a great number of trees which have now grown to 

 sapling and pole-wood size and have so thoroughly occupied the space 



♦McDougall, w. P.. 



(1) Forests and Soils of Vermilion County, Illinois, with special Ref- 

 erence to the Striplands. Ecology, Vol. VI, Xo. 4, p. 376. Oct. 1925. 



(2) Symbiosis in a D'eeiduous Forest. Botanical Gazette, Vol 7.1 Xo 

 ?,. ATnrcti, 19 9 2. 



