Biological Station 



ing a pine forest, now, following cutting and repeated burning, it is 

 covered with aspens. These are small, short-lived trees, which are 

 important in the revegetation of burnt over areas. Among the aspens 

 are frequent pines ranging in size from seedlings to cone-bearing 

 trees. With sufficient protection from fires such areas are due to be 

 reforested with pine in a comparatively short time. 



The lowlands are usually occupied by bogs exhibiting various 

 stages of development. Such trees as white cedar (arbor vitae), 

 tamarack, spruces and balsam are abundant. The flora is typically 

 northern. It includes several orchids, insect-catching plants, as the 

 pitcher plant and sundew, and the dwarf mistletoe. 



Ponds, several lakes, mostly small, and a few streams, all of 

 which are small, furnish a diverse series of habitats, each with its 

 characteristic flora. 



Sand dunes along Lake Michigan supplement the very small ones 

 in the Douglas Lake region. 



The region in which the Station is located thus offers consider- 

 able diversity of original conditions which have in many respects 

 undergone modifications by fire, permitting great vegetational changes 

 which admit of a very adequate presentation of ecological principles. 



Among the problems in plant ecology suggested by the region 

 are : the development of certain habitats, successional relationships, 

 correlation of vegetation and evaporation, physiological limitations 

 of habitats and species, growth increments under varying conditions, 

 changes in soil and vegetation due to cutting, burning, draining, 

 planting, and seeding. 



The region likewise offers a rich field for scientific work with 

 the Cryptogams. Algae abound in the lakes, pools and streams ; lich- 

 ens, mosses, ferns, and the fern allies may be found in abundance 

 in habitats varying from Sphagnum and Thuja bogs to the dry, 

 sandy aspen associations. Rusts, smuts and other parasitic fungi in- 

 fest a vast variety of hosts, offering an abundance of material for the 

 investigator. The study of the Cryptogams is practically a virgin 

 field at the Station, little work having been done in that line. There 

 is, however, a collection of lichens and mosses for comparative study. 



For the study of animals the region is probably not quite so well 

 adapted as it is for the study of plants. The fauna is not as rich 

 as it is in the southern parts of the state. Mammals are few, the 

 number of species of amphibians, reptiles and fish is small but the 

 number of individuals is sufficient for good collecting. The fish fauna 

 of the chain of lakes of which Douglas Lake is a part and their 

 tributaries is interesting and well worth study in comparison with the 

 fauna of the Great Lakes. Birds are sufficiently numerous and the 

 range of their habitats within easy reach of the Station is such that 

 good work can be done. Numerous problems dealing with the ecology 

 of birds, their behavior, and the activities of breeding and nesting 

 birds await attention. A fair proportion of the birds which nest 

 there are known to most ornithologists as migrants only. 



The invertebrate fauna is relatively much richer than the verte- 



