History of Forest Ecology 425 



mont. This is the proper place for these investigations and it is to 

 be hoped that every state in the Union will emulate Vermont. This 

 would eventually lead to a Forest Experiment Station coordinate with 

 the Agricultural Experiment Station in every state. 



The most important recent contributions in government 

 literature have been in the direction of the effect of forests on 

 climate and streamflow (64, 65, 66, 67, 89). Zon has summarized 

 the work done in this field both here and abroad very completely 

 (68). A bulletin by Bates (69) upon Windbreaks studied the in- 

 fluence of windbreaks upon climate, especially humidity, wind 

 and temperature, and being worked out according to modern 

 ecological methods, marks a distinct advance. A bulletin by 

 Graves and Zon (72) upon Light in Relation to Tree Growth gives 

 a resumd of the work done in determining light values in the woods. 

 It is a sure indication of a closer scrutin}'- of habitat factors in 

 silvicultural work. A third bulletin along the same lines was writ- 

 ten by Clements (73) upon The Life-History of Lodgepole Burn 

 Forests. This war an investigation in forest ecology by a plant 

 ecologist and was one of the first attempts to apply the principles 

 and methods of plant ecology to a forestry problem. 



The periodic forestry literature (70, 71) deaHng directly or in- 

 directly with applied ecology in the United States during the last 

 12 years reveals the beginning of the study of certain great silvi- 

 cultural problems in a systematic manner. The contributions 

 are almost entirely by members of the U. S. Forest Service who 

 are in an excellent position to undertake the study of the varied 

 field problems. Although the data are to a considerable extent 

 based on general observations rather than on conclusions based 

 upon quantitative data yet we must admit that they have no 

 small value. That foresters have followed the observational 

 method for gathering their facts rather than the experimental is 

 due to difficulties over which they have no control. We have 

 begun to study our problems in an empirical way, but the methods 

 of plant ecology are beginning to make themselves felt. When 

 we happen upon a title like The Climatic Characteristics of Forest 

 Types we begin to realize that the exact determination of silvical 

 facts by means of systematic experimentation has begun. The 

 complete silvical description of our important species based upon 

 field studies is nearing completion. The effect of fires, snow and 

 insects, both as they affect forest succession and the life of the 



