124 



2. Dry Upland (Qucrcus and Carya) Forest Association 



The upland oak-hickory forest community is upon high well- 

 drained land. It is bordered by a ravine and a valley, so that the pre- 

 cipitation drains away rapidly. The soil, in contrast with that of the 

 black soil prairie, is a gray loam, containing little organic debris. 

 Through clearing, the woods have become relatively open, so that the 

 sunny spots are rather numerous. The characteristic vegetation con- 

 sists of oaks and hickories, such as white oak (Quercus alba), black 

 oak (0. velutina), shag-bark hickory (Carya ovata), pignut (C. gla- 

 bra) ; and of rose, raspberry, sassafras (Sassafras varii folium) , sumac 

 (Rhus glabra), young trees, horsemint (Monarda) everlasting (An- 

 tennaria) and tick-trefoil (Desmodium). The conditions are those 

 of Station IV, a, the upland Bates woods, and the open ravine slopes, 

 IV, b. 



Representative animals of this community, including numerous 

 ground-inhabiting Orthoptcra — many of the acridiids being short- 

 winged forms — are Dichromorpha viridis, Chlocaltis conspersa, 

 Spharagcnwn bolli, Mclanoplus atlanis, amplcctcns, obovatipcnnis, 

 and scudderi, Scuddcria fnrcata, Microccntruin laurifoliam, Orchcli- 

 mum cuticulare, Xiphidium ncnwrale, Ncmobius fasciatus and maca- 

 latits, Apitluis agitator, Cicindcla unipunctata, Calosonia scruta- 

 tor, Chrysochus auratus (on dogbane in an open area), Myrmeleoni- 

 dcc, and Sphccrophthahna. Several species of butterflies were seen on 

 the wing in the sunny openings. A number of cecidomyid and cyni- 

 pid galls on oaks and hickories are more characteristic of the upland 

 forest than of the lowland forest on account of paucity or absence 

 of white and black oaks and hickories upon the bottoms. Other 

 upland plants determine in a similar manner the presence of other 

 animals. 



As a forest develops, upon what has previously been a treeless 

 tract, and as wood therefore becomes an available animal habitat, a 

 very complex factor is added to the environment. Not only is a log 

 food for certain animals, but also, if it lies upon the ground, it affords 

 conditions favorable for still others. It tends to conserve moisture 

 under it, and as it decays and disintegrates, fungi grow upon and in it ; 

 hence other food is produced for animals which are not eaters of wood. 

 As decay progresses, furthermore, the log itself readily absorbs and re- 

 tains moisture, thus giving to some animals within it a habitat with 

 atmospheric conditions of relatively high humidity, in which land mol- 

 lusks, diplopods, etc., thrive. Such conditions furnish an important 

 factor in the extensive range of certain animals throughout several 

 kinds of forest ; for though the kinds of trees may change, nevertheless 



