CONTENTS 



Introduction iv 



Part I. Description of the forests 1 



Physiograpliic features 1 



The original forests of Illinois 2 



Outline of forest use from original to present forests 6 



Present forests of Illinois 8 



General comparison of bottomland and upland forests 8 



Forest types 9 



Bottomland types 10 



Upland types 11 



Bottomland type: 



(1) Cypress and mixed hardwood 12 



(2) Mixed hardwood bottoms of the main streams 16 



The Wabash River system 17 



The Big Muddy River system 21 



The Kaskaskia River system 23 



The Mississippi River system 24 



The Illinois River system 28 



The Rock River system 30 



(3) Mixed hardwoods of bottoms of secondary streams 30 



Upland type: 



(1) Post oak 32 



(2) Scrub-oak 35 



(3) Upland hardwoods 41 



Subtype (a) upland mixed hordwoods 42 



Subtype ( b ) oak-hickory 54 



Forest acres by counties — present (1924) and original 58 



Plates MX G4-72 



Part 11. Growth and yield studies 73 



(1) Studies of growth rates of individual trees 73 



[Table 1, showing soil type best suited to certain species] 78-79 



[Table 2, showing species best suited to specific soil type] SO 



Table 3. Average growth-rates on specific soil-types for 20-year 



periods for 25 tree species to show soil type best suited to 



species S1-S9 



[Lists summarizing results of studies of average growth] 90-91 



[Illinois counties classified on basis of soil reports: 



(1) those for which maps are available; (2) those for which 

 unpublished information is available; (3) those for which no 



information is available] .• 92 



(2) Studies of yields 92 



Post-oak type 93 



Scrub-oak type 94 



Upland hardwood type 94 



Bottomland type 95 



Yield tables for even-aged stands in Illinois 95 



(1) Upland types: 



Post-oak type 95 



Scrub-oak type 96 



Upland harilwood type 96 



(2) Bottomland type: 



[Rapidly growing species] 96 



[Slow-growing species] 97 



(3) [Fully stocked virgin stands:] 



Upland hardwoods 97 



Bottomland stands 97 



Part III. Proposed state forest policy 98 



Conclusion 101 



Literature cited 102 



iii 



