57 



the area examined was well drained, and all was forested. The region 

 is not homogeneous physically or in its vegetation, and for this reason 

 the area is divided into substations in order that the influences of the 

 local conditions within the forest might be preserved, and their indi- 

 viduality recognized. 



2. The Upland Oak-Hickory Forest, Station IV, a 



The general appearance of this forest is shown in plates XII and 

 XIII. This is an open second-growth forest composed of oaks and 

 hickories — such as white oak (Qucrcus alba), black oak (0. velutina), 

 shag-bark hickory (Carya ovata), bitternut (C. cordiformis) , pignut 

 (C. glabra), and scattered individual trees of red oak (0. rubra), wal- 

 nut (Juglans nigra), and mulberry (Morns rubra). The shrubs are 

 sassafras (Sassafras variifolium) , sumac (Rhus glabra), Virginia 

 creeper (Psedera quinqucfolia), poison ivy (Rhus toxicodendron), 

 rose (Rosa), raspberry (Rubus), moonseed (Mcnispcrnutni cana- 

 dense), and tree seedlings. The average diameter of the largest trees 

 is 8-IO inches. Most of the small growth consists of the sprouts from 

 stumps, and many of these are 2-3 inches in diameter. The forest 

 crown is not complete, and as a consequence there are more or less open 

 patches in which most of the herbaceous growth is found, such as 

 horse mint (Monarda bradburiana), pennyroyal (Hcdcoma pule- 

 gioides), everlasting (Antennaria plantaginifolia) , tick-trefoil (Des- 

 modium nudifloruui) , and other, less abundant kinds. Even a plant 

 quite characteristic of the prairie, the dogbane Apocyuum, was found 

 here in one of the open glades. 



The forest floor has an unequal covering of dead leaves, largely 

 oak, most of which lie in the low vegetation and in slight depressions. 

 Occasionally there is but little cover and the light-colored soil is ex- 

 posed. There are few stumps and logs in this part of the forest, and 

 no thick layer of vegetable mold, so that one would not expect to find 

 any animals which normally frequent moist soil and vegetable debris. 

 As this is a second-growth forest it lacks the conditions which abound 

 in an original growth, where are old, dead and decaying trees, and 

 numerous decaying logs and stumps. In this respect the woods is not 

 fully representative of an original upland forest on well-drained bluff 

 land. 



The relative evaporating power of the air of this substation was 54 

 per cent, of that of the standard instrument in the open garden at the 

 Normal School, a fact which indicates a relative evaporation com- 

 parable to that of the ordinary black-soil prairie ; in producing this con- 

 dition, the glade-like, open character of this forest is undoubtedly 

 an important factor. 



