ARBORICULTURE 



ARBORICULTURE 



377 



In studying the forest trees of the Great Plains of 

 central North America, it is found that most of the species 

 have migrated out upon the Plains from the great forest 

 body of the Mississippi Valley. These trees found their 

 way upon the Plains by way of the forests that border 

 the Missouri River and its tributaries. As we pass down 

 the river, along the eastern edge of the Plains, the forest 

 belt becomes larger and larger, until it eventually 

 merges into the great body of forest trees lying on the 

 easterly side of the Mississippi Valley. The principal 

 trees that have come upon the Plains by this route 

 are the common red cedar, papaw, half a dozen willows, 

 one cottonwood, basswood, two or three elms, hack- 

 berry, mulberry, three ashes, wild apple, four or more 

 species of hawthorns, juneberry, wild cherry, choke 

 cherry, wild plum, coffee bean, honey locust, redbud, 

 sycamore, two species of buckthorns, buckeye, one 

 maple, box elder, sumach, two species of walnuts, five 

 or six hickories, nine or ten oaks, ironwood, blue beech, 

 and one birch. But ten species of trees have come from 

 the Rocky Mountain forests, and these have made much 

 less impression upon the forests of the Plains than those 

 that came from the eastern forests. In this list are the 

 bull-pine, the western red cedar, four species of cotton- 

 woods, the buffalo berry, a maple, and two birches. 



Although the present forest area of the Plains is not 

 relatively great, it is large enough to be seriously consid- 

 ered in regard to its preservation. There is danger that 

 with the habit acquired by our people in the thickly 

 wooded parts of the United States of cutting down 

 forest trees wherever found, much of this small forest 

 area will be destroyed. It is much easier to preserve an 

 area of forest growth than to create it anew. First, all 

 forest fires must be kept down. When a mass of wood- 

 land adjoins the open prairie, fire-guards should be made 

 BO that the fires will not sweep into the forest growth. 

 The greatest destroyer of the forests of the Plains in 

 the past has been fire, as it swept over the prairies into 

 woodland. Second , it is absolutely necessary to keep out 

 certain kinds of stock. Swine, if herded in large num- 

 bers, will inevitably destroy the trees. They prevent 

 the growth of small trees, and eventually destroy those 

 of larger growth. Cattle, in large numbers, are equally 

 destructive. In fact, when the attempt is made to pre- 

 serve uninjured the trees in a forest, it is necessary to 

 keep out stock of all kinds, excepting possibly during 

 limited portions of the year. Third, it is necessary to 

 cut out the trees for use with very great care. A forest 

 should be a permanent crop, and the cuttings should 

 be so made that the forest as a whole is not injured. 

 Trees should be cut here and there in such a way that 

 the young trees which are left have an opportunity for 

 growing into usable timber. 



Care should be taken to encourage the tendency to 

 spreading which is so strong in nearly all parts of the 

 Plains. With a little care every present living forest 

 area may be made to extend itself spontaneously, or 

 nearly so. The forest should be effectually inclosed by 

 a fence, placed at some distance from its outer border, 

 leaving a belt of unoccupied land between the trees 

 and the fence. This will grow up with weeds, and 

 mingled with these will be the seedling trees springing 

 from the seeds blown or carried from the forest area. 

 In this way the border of the forest will be gradually 

 extended. This can be helped by plowing up these 

 inclosed belts of land, giving better opportunity for the 

 starting of seedling trees. With the weeds and little 

 trees will spring up low shrubs of various kinds. These 

 need give no trouble, for this is merely Nature's way 

 of taking possession of the soil. Little, if any, cultiva- 

 tion need be given to such a nursery belt, as the weeds 

 which spring up, while unsightly, will serve the useful 

 purpose of sheltering the little trees, and eventually 

 the trees will rise above, and choke them out. Grass, 

 however, forming a tough sod, is harmful to the little 

 trees, far more so than the ordinary weeds. 



There are many places in which actual planting must 

 be resorted to. In looking about for a site for the new 

 forest plantation, it must be remembered that the best 

 conditions for tree growth are usually to be found near 

 the natural forests. Where there are natural forests, the 

 planting should be around their borders, so as to extend 

 them in much the same way as indicated in the pre- 

 ceding paragraph in regard to natural spreading. 

 Where there are no natural forests at all, it is necessary 

 to select the more favorable places for planting. Since 

 the natural forests on the Plains occupy the depressions 

 rather than the hilltops or the slopes, this should give 



357. A good field elm. 



one a hint as to what must be done. Wherever the land 

 slopes into a depression, one may find favorable condi- 

 tions for growing trees. These depressions, generally 

 called "draws," may be filled with trees, and when once 

 a growth of a few acres is secured it will not be difficult 

 to extend the forest far up the hillside slopes. On the 

 western parts of the Plains similar positions should 

 be taken under the irrigation ditches. In the selection 

 of trees for the formation of forest areas, one should 

 also take a hint from nature. The rule, which is a very 

 excellent one for the plainsman to follow, is to plant on 

 his farm the kinds that he finds in the nearest forest, 

 and to give his planted trees as nearlyas possible the same 

 conditions as those under which they grew in the native 

 forest. On the eastern third of the Plains, the walnut, 

 white oak, shellbark hickory, white elm, red elm, hack- 

 berry, white ash, wild cherry, catalpa and honey locust 

 are recommended for planting. On the extreme eastern 

 parts bordering the Missouri River, many more kinds 

 can be planted, but as one passes westward toward the 

 borders of the Sand Hill region the list grows smaller. 

 On the central Plains the list is reduced, and also some- 

 what changed in species. The two elms may be planted, 

 as also the hackberry, the green ash in place of the white 

 ash, wild cherry, honey locust, and in many places the 

 bull-pine. On the western Plains, especially that por- 

 tion lying west of the main body of the Sand Hills, and 

 having an elevation above the sea of from 3,000 to 4.000 

 feet, the list is still smaller. The white elm is still in- 

 cluded, also the hackberry, the bull-pine, and in many 

 places the red cedar. 



The trees mentioned are of the more durable and 

 profitable kinds. But on all parts of the Plains persons 

 must often have quick-growing trees, which soon pro- 

 duce fuel, but which have little, if any, value for other 

 purposes. In the eastern part of the Plains, the black 

 willow, almond willow, common cottonwood, silver 

 maple, and box elder are useful trees for this purpose. 

 One should not condemn the use of these easily grown, 

 soft-wooded trees. A forest is a crop, and there is no 

 reason why a farmer may not plant a more quickly 

 growing crop if he wishes, but he should at the same 

 time plant the more enduring kinds given in the preced- 



