266 ILLINOIS ACADEMY OF SCIENCE 



The usual oak upland type with medium sized trees 

 covers two-thirds of the area (developing upon the timber 

 soil along the creeks). It is heavily grazed and shows 

 little or no reproduction. Upon the slopes of the stream 

 valleys in Section 3 and 4 cutting was in progress at two 

 points, the trees being converted into fence posts and mine 

 timbers. 



La Salle Township ( Map V ) . 



Although a small township, extending only three miles 

 from east to west, La Salle exhibits a considerable diversity 

 of topography on account of its bisection by the Illinois 

 River. This stream divides it into three distinct regions 

 consisting of a broad, flat river valley flanked on the north 

 and south by steep slopes leading to uplands nearly 200 

 feet above the level of the stream. South of the Illinois 

 River the eastern boundary of the township is the winding 

 course of the Vermilion River which joins the Illinois about 

 one mile southeast of the city of La Salle. 



According to the maps of the soil survey the "timber 

 soils" occupy approximately 4,500 acres and the bottom 

 lands slightly over half (2,300 acres) that amount. Upon 

 the former soils are situated the city of La Salle and the 

 village of Oglesby and this, together with the areas cleared 

 and under cultivation, reduces the ;area actually covered 

 by tree growth to not more than 800 acres including many 

 half -denuded slopes. 



By far the largest continuous area is along the Little 

 Vermilion and more especially upon the east side of the 

 stream in Sections 2 and 1. In the former the stream has 

 a flood plain over 300 yards wide but this lias been largely 

 cleared and is now being cultivated, the forest being re- 

 stricted to the steep bluffs bordering the valley, to the 

 tributary ravines and to portions of the immediately ad- 

 jacent uplands. This reduces the bottom forest to a van- 

 ishing remnant and results in the dominance of the oak 

 upland forest in which the white oak is conspicuous. Up- 

 on the steeper slopes red cedar, hop hornbeam, basswood, 

 service berry (Amelanchier) and an occasional white pine 

 are to be found, while towards the foot of the bluffs some 

 trees of the bottom forest occur. 



