The Forest Habitat of the University of Kansas Natural History Reservation Part 2

In the thirties when most of the woodland area was fenced off and protected from grazing, three wooded hillside areas of a few acres each, were maintained as connecting strips between the pastures of the hilltops and those of the bottomlands. These areas were utilized only at certain seasons, but by 1948 the effect of trampling and heavy browsing by livestock was conspicuous. Herbaceous ground vegetation was almost lacking and low woody vegetation was also scarce, in contrast to the parts of the woodland that were adjacent but separated by fences that excluded livestock. The contrast was perhaps heightened along the fences because the animals tended to follow along the fence lines and their effects were concentrated there.

Table 4.--Numbers of Young Trees of Various Kinds and Sizes in 1954 on a .919-acre Area Consisting of Six Hillside Strips Each 20 Feet Wide. Each Strip Was Equally Divided by a Fence Line, Excluding Livestock from One Side During the Period 1934 (Approximately) to 1948.

---------------------------------------------------------------------- Less than -inch -inch to 4-inch 5-inch to 12-inch stem diameter stem diameter stem diameter -------+---------+-------+---------+-------+--------- Percent- Percent- Percent- Total age in Total age in Total age in number browsed number browsed number browsed half half half ----------------+-------+---------+-------+---------+-------+--------- Dogwood 556 52.1 1058 16.4 Redbud 40 42.5 102 5.9 Elm 30 76.7 189 27.6 99 47.5 Hackberry 131 39.7 206 13.1 5 20.0 Plum 26 77.0 35 22.8 1 100.0 Crab-apple 11 100.0 46 37.0 Red haw 1 100.0 33 48.5 9 75.8 Walnut 7 28.6 32 43.7 26 61.5 Honey locust 2 100.0 20 15.0 11 27.3 Osage orange 1 100.0 7 57.1 2 50.0 s.h.a.gbark hickory 3 100.0 42 73.8 44 40.9 Chestnut oak 26 30.8 24 58.2 Chinquapin oak 12 100.0 1 100.0 Coffee-tree 11 18.1 8 12.5 Ailanthus 6 33.3 65 26.1 3 100.0 Black oak 5 40.0 7 16.6 American ash 21 100.0 3 33.3 Paw paw 12 61 27.8 ----------------+-------+---------+-------+---------+-------+---------

In 1954 ten-foot wide strips were sampled on both sides of the fences.

For both browsed and unbrowsed samples, the strips had a total length of 4000 feet, each representing an area of .919 acres. Table 4 contrasts the number of young trees per acre on the browsed and unbrowsed areas, grouped in several size cla.s.ses. In general the saplings up to one-fourth inch in diameter were those that had become established in the five growing seasons since browsing was discontinued and both areas were protected. For this size group the numbers were approximately equal, being slightly higher on the browsed strips. However, in the size group of inch to 4 inches in stem diameter, the trees were nearly three times as abundant on the unbrowsed areas, and most trees within this size range must have become established within the time of differing treatments. The disparity in numbers was great for hackberry, redbud, elm and dogwood which made up the bulk of the saplings. In the size range 5 to 12 inches most trees antedated the fence, and the unbrowsed portion had only a few more than the portion that had been browsed.

On the formerly browsed areas clumps of gooseberry bushes were conspicuous and were computed to cover 3.81 per cent of the area sampled, versus 2.87 per cent on the unbrowsed area. These th.o.r.n.y bushes seem to be resistant to browsing, and elsewhere have been noted in abundance in woodlands heavily used by livestock. The elimination of competing undergrowth by browsers may be a factor favoring development of gooseberry clumps. The trend was just the opposite for fragrant sumac, which was computed to cover 1.94 per cent of the browsed sample versus 3.23 per cent of the unbrowsed sample.

Greenbrier (_Smilax tamnoides hispida_) was most abundant on the unbrowsed strips, with seven large clumps, and 56 smaller clumps (10 stems or fewer) as contrasted with five large clumps and 32 smaller clumps on the browsed strips. There were 32 grapevines (_Vitis vulpina_) on the unbrowsed strips and only seven on those that were browsed.

Animal a.s.sociates

The invertebrates of the University of Kansas Natural History Reservation have not been intensively studied. Most of the species of vertebrates are characteristic of the deciduous forest of the eastern United States, or of the edge of woodland; relatively few kinds are characteristic of prairies.

Of birds, for example, some 23 species characteristic of the eastern deciduous forests have been found nesting on the Reservation, as have 14 additional species that are mainly eastern in their distribution but are most characteristic of forest-edge thickets, clearings, or marshy places. The ruffed grouse (_Bonasa umbellus_) and wild turkey (_Meleagris gallopavo_) are not present on the area, although they may have occurred there earlier. Other forest birds which occur in the general area, and which have been recorded from time to time on the Reservation, although they seem not to nest there, are: chuck-will's-widow (_Caprimulgus carolinensis_), scarlet tanager (_Piranga olivacea_), Acadian flycatcher (_Empidonax virescens_), veery (_Hylocichla fuscescens_), parula warbler (_Parula americana_), oven-bird (_Seiurus aurocapillus_), and orchard oriole (_Icterus spurius_). For each of these, habitat conditions on the Reservation seem to be deficient in some respect. On the other hand, the only typical prairie bird that breeds on the Reservation is the d.i.c.kcissel (_Spiza americana_). Others, including the Swainson hawk (_Buteo swainsoni_), greater prairie chicken (_Tympanuchus cupido_), upland plover (_Bartramia longicauda_), western kingbird (_Tyrannus verticalis_) and loggerhead shrike (_Lanius ludovicia.n.u.s_), occur in the general area, and may even cross the Reservation at times, but they do not become established.

In the mammalian fauna, species typical of the deciduous forests include the opossum (_Didelphis marsupialis_), short-tailed shrew (_Blarina brevicauda_), eastern mole (_Scalopus aquaticus_), eastern gray squirrel (_Sciurus carolinensis_), and pine vole (_Microtus pinetorum_), but the eastern chipmunk (_Tamias striatus_) and southern flying squirrel (_Glaucomys volans_) are lacking. Also, the present fauna lacks large mammals that may have been present under original conditions: the white-tailed deer (_Odocoileus virginia.n.u.s_), recorded on the area from time to time but not permanently established there, the wapiti (_Cervus america.n.u.s_), black bear (Ursus america.n.u.s), and bobcat (_Lynx rufus_). Other species on the area, that are characteristic of the deciduous woodlands, but that occur also far west into prairie regions, include the little short-tailed shrew (_Cryptotis parva_), racc.o.o.n (_Procyon lotor_), fox squirrel (_Sciurus niger_), white-footed mouse (_Peromyscus leucopus_), eastern woodrat (_Neotoma floridana_) and eastern cottontail. On the area, the only mammals that are sharply confined to gra.s.slands, elsewhere as well as on the Reservation, are the plains pocket gopher (_Geomys bursarius_) and plains harvest mouse (_Reithrodontomys monta.n.u.s_), both of which are rare on the area, and the hispid cotton rat (_Sigmodon hispidus_).

The following species are typical of the plains, but they range eastward into the region of deciduous forests: western harvest mouse (_Reithrodontomys megalotis_), deer mouse (_Peromyscus maniculatus_), coyote (_Canis latrans_), and spotted skunk (_Spilogale putorius_).

The following mammals, typical of gra.s.sland, are absent: black-tailed jack rabbit (_Lepus californicus_), black-tailed prairie dog (_Cynomys ludovicia.n.u.s_), 13-lined ground squirrel (_Spermophilus tridecemlineatus_), Franklin's ground squirrel (_Spermophilus franklinii_), southern lemming-mouse (_Synaptomys cooperi_), and of course, the buffalo (_Bison bison_), and the p.r.o.ng-horned antelope (_Antilocapra americana_) long extinct in this part of their range.

Of amphibians and reptiles also, the majority are typical forest species, including: the American toad (_Bufo terrestris_), common tree frog (_Hyla versicolor_), brown skink (_Lygosoma laterale_), common five-lined skink (_Eumeces fasciatus_), worm snake (_Carphophis amoenus_), pilot black snake (_Elaphe obsoleta_), DeKay snake (_Storeria dekayi_), western ground snake (_Haldea valeriae_), copperhead (_Agkistrodon contortrix_), and timber rattlesnake (_Crotalus horridus_). Other typical forest species missing from the area include the spring peeper (_Hyla crucifer_), Carolina box turtle (_Terrapene carolina_), coal skink (_Eumeces anthracinus_), and red-bellied snake (_Storeria occipitomaculata_). Of typical prairie species only the Kansas ant-eating frog (_Gastrophryne olivacea_) and the ornate box turtle (_Terrapene ornata_) are common, and, curiously, each seems to prefer a forest habitat on this area, in the absence of their closely related eastern representatives, the eastern ant-eating frog (_G. carolinensis_) and the Carolina box turtle, respectively, which usually live in forests. The plains spadefoot (_Spea bombifrons_), garden toad (_Bufo woodhousii_), Great Plains skink (_Eumeces obsoletus_), prairie skink (_Eumeces septentrionalis_), slender tantilla (_Tantilla gracilis_), prairie rat snake (_Elaphe guttata_), bull snake (_Pituophis catenifer_), and blotched king snake (_Lampropeltis calligaster_) are all scarce on the area. The plains toad (_Bufo cognatus_), collared lizard (_Crotaphytus collaris_), except for an introduced colony, plains garter snake (_Thamnophis radix_), lined snake (_Tropidoclonion lineatum_), and ma.s.sa.s.sauga (_Sistrurus catenatus_) seem not to occur on the area at all.

Annotated List of Species

#Juniperus virginiana.#--Red cedar, the only native gymnosperm of northeastern Kansas, occurs in nearly all woodlands of the region, although individual trees are widely scattered. It has increased remarkably in the past few years. No mature cedar trees grow anywhere on the Reservation, but young trees, probably several dozen in all, are widely scattered in a variety of situations on the area. Probably in every instance the seeds have reached the area in droppings of birds. Approximately 15 miles south and a little east of the Reservation is a stand of cedars some of which are 100 to 300 years old. Near the southwest corner of the section, at the site of a former farm house there is a small grove of these trees, probably planted.

These may have been the source for some of the young trees on the Reservation.

On several occasions cardinals (_Richmondena cardinalis_) were observed to have nested in the young cedars, whose thick foliage provided well sheltered nesting sites. This shelter was utilized especially in early nestings when foliage had only begun to appear on other trees and shrubs. However, two such nests in cedars, that were checked repeatedly, were eventually destroyed by predators.

#Salix nigra.#--Black willow is localized in the vicinity of the one small pond on the Reservation. The pond was made in 1936; at the upper end of a small valley a dirt bank 100 yards long was built across a ravine through which an intermittent creek drained. Hilltop fields draining into this ravine were then under cultivation. In the next few years heavy erosion occurred in the upland fields, and the soil carried downstream was deposited in the pond. Most of the pond was filled up with a silt flat about an acre in area. On the higher part of this silt flat a dense thicket of saplings of elm, honey locust and osage orange sprang up. On the lower, wetter part of the silt bar a willow grove grew up, dominated by _S. nigra_, with _S.

eriocephala_, _S. interior_ and _S. amygdaloides_ in smaller numbers.

By 1955 some of these trees had attained a trunk diameter of eight inches and a height of thirty feet. Elsewhere on the Reservation, willow is represented only by a few scattered trees and bushes along the two intermittent creeks. The silty soil preferred by the willow is scarce as both streams are actively eroding their channels.

The moist, silty soil beneath the willow grove is covered with a dense mat of low vegetation including giant ragweed, carpenter's square, dayflower, and rice cutgra.s.s. Short-tailed shrews, house mice (_Mus musculus_), harvest mice and cotton rats thrive in this habitat.

Red-winged blackbirds (_Agelaius phoeniceus_), yellow-billed cuckoos (_Coccyzus america.n.u.s_), red-eyed vireos (_Vireo olivaceus_), catbirds (_Dumetella carolinensis_) and Kentucky warblers (_Oporornis formosus_) use it for nesting. The high humidity and dense vegetation in this grove render it favorable habitat for recently metamorphosed frogs and toads, especially the tree frog, which is sometimes extremely abundant there in summer.

#Populus deltoides.#--Cottonwood is one of the less common trees on the area, but it attains a larger size than any of the other kinds.

The larger of the two creeks on the Reservation is lined with mature cottonwoods along the lower part of its course. Along the smaller creek large cottonwoods are also present but they are more widely s.p.a.ced. A few cottonwoods are present at well scattered points on slopes and hilltops, usually in forest edge situations or in woodland where other trees are spa.r.s.e. By far the largest tree on the Reservation is a cottonwood of 15-foot circ.u.mference (Plate 1), growing on a hilltop near the south boundary of the Reservation, at the edge of woodland adjacent to a cultivated field.

The heavy rainfall of 1951 resulted in the establishment of hundreds of cottonwood seedlings, mostly in places remote from the mature trees. So far as observed, all these were in recent silt deposits.

Many of them have survived the drought of 1952-1954.

Because of their great height, towering above the level of the surrounding tree-tops, cottonwoods are preferred look-out perches of certain of the larger birds, notably red-tailed hawks (_Buteo jamaicensis_), barred owls (_Strix varia_), and crows (_Corvus brachyrhynchos_). Flocks of robins (_t.u.r.dus migratorius_) and of rusty blackbirds (_Euphagus carolinus_) preparing to roost have been noted habitually to gather in the tops of tall cottonwoods. In spring, large wandering flocks of goldfinches (_Spinus tristis_) have been seen feeding on the leaf buds of cottonwoods. Baltimore orioles (_Icterus galbula_) and yellow-billed cuckoos often forage in cottonwoods. Red-bellied woodp.e.c.k.e.rs (_Centurus carolinus_) spend a disproportionately large amount of their time in cottonwoods. These woodp.e.c.k.e.rs have been observed nesting in the hollow branches on several occasions. Downy woodp.e.c.k.e.rs (_Dendrocopos p.u.b.escens_) also have been noticed foraging in cottonwoods on many occasions. Certain large isolated cottonwoods along creeks were favorite stopping places of blue jays (_Cyanocitta cristata_) which, on trips from one wooded hillside to another, usually perched briefly in the tops of these tall trees.

Calling and looking about, the jays seemed to maintain contact with distant mates or members of the flocks by using these high perches.

Often after a brief pause in the top of the cottonwood they flew off in a new direction.

Both woodrats and opossums have been known to utilize hollow cottonwoods as dens. Fox squirrels have been seen climbing in cottonwoods occasionally.

#Juglans nigra.#--Black walnut is one of the more prominent hardwoods.

Under original conditions, evidently many of the larger trees were of this species. Being the most valuable timber species of the area, walnut has been subjected to heavy cutting over the past 85 years.

Most of the walnut trees still present are small or medium-sized, but the species is still abundant over much of the area. Along certain hilltop edges there are groves of walnuts, growing in nearly pure stands, with an occasional elm, ash, coffee-tree or honey locust.

Elsewhere walnut trees are more scattered, but are distributed throughout the woodland. Although the walnut trees growing in woods are of various sizes from those of mature size down to saplings, seedlings are to be found mainly in fields near the woodland edge. In these situations it is one of the more prominent of the woody species invading open lands. The seeds evidently are transported mainly by rodents, especially fox squirrels.

In autumn every walnut tree that is bearing nuts becomes a focal point of activity for squirrels. Over a period of weeks the squirrels concentrate their attention on the walnut crop, continuing until virtually every nut has been harvested. Walnut seems to be the one most important food source, for both the fox squirrel and the gray squirrel. Most of the nuts are stored for future use. Many buried separately and never retrieved by the squirrels, grow into new trees.

White-footed mice often store the nuts in their nests, in burrows, beneath rocks or in crevices. In summer, groves and isolated trees of walnuts are favorite haunts of the yellow-billed cuckoo, which finds concealment in the thick foliage, and probably feeds upon the tent caterpillars that commonly infest these trees.

#Carya ovata.#--s.h.a.gbark hickory is one of the more important hardwoods of the area. The trees are relatively small compared with the larger oaks, elms, ashes and hackberry. However, on several parts of the area this hickory is dominant. It grows mainly on north slopes and hilltops. The trees most frequently a.s.sociated with it are black oak, American elm and chestnut oak. Scattered through the woodlands are occasional mature hickories of DBH 18 inches or more. However, many of the trees are six inches or less DBH and a large proportion of these have originated as stump sprouts from trees cut in the early thirties or before.

s.h.a.gbark is especially tolerant of shading. Numerous young trees and seedlings noted all were growing in dense woods of larger hickories, oaks, or mature elms. None has been found in open fields or even in edge situations. This hickory is resistant to drought; relatively few died during the drought of 1952-1954, and these were mostly small trees in crowded stands.

In parts of the woodland dominated by s.h.a.gbark hickory the trees are mostly 5 to 6 inches or even smaller in trunk diameter and 20 to 30 feet high, sometimes growing in nearly pure stands, and with a leaf canopy so dense that shrubs and herbaceous vegetation are spa.r.s.e.

The mast crop produced by s.h.a.gbark is an important food source for both fox squirrels and gray squirrels. Both kinds of squirrels often use these hickories as sites for their stick nests. White-footed mice also store the nuts as a winter food source.

Birds which are most often seen in groves of s.h.a.gbark include the yellow-billed cuckoo, tufted t.i.tmouse (_Parus bicolor_), black-capped chickadee (_P. atricapillus_), blue jay, summer tanager (_Piranga rubra_), and red-eyed vireo. The Cooper hawk (_Accipiter cooperii_) has been recorded nesting in this hickory. In dead trees of this species that are still standing, the interiors may decay more rapidly than the armorlike bark plates. On several occasions tufted t.i.tmice and chickadees have been recorded as nesting in such cavities.

#Quercus stellata.#--Post oak is relatively scarce on the Reservation.

One area of approximately an acre on a south slope is dominated by it.

There are several other small groves and scattered trees. All are on moderately steep south slopes in poor soil. Trees often found a.s.sociated with it include red elm, chestnut oak, chinquapin oak, blackjack oak, hickory, and dogwood. It seems likely that under original conditions this species occupied about the same area as it does at present. It is not spreading, and there are few young trees anywhere on the area. In every instance the groves are limited to a rocky clay soil, and edaphic factors obviously are of major importance. Under original conditions fire was probably a limiting factor, and at the present time compet.i.tion with other hardwoods may be even more important.

#Quercus macrocarpa.#--Less than a dozen individuals of mossycup oak have been noticed on the area, at well scattered points. Under original conditions, it probably grew chiefly in the bottomlands that have been completely cleared of timber for cultivation. The few now present are all on hillsides, and are medium to large trees.

#Quercus Muehlenbergii.#--Chestnut oak was perhaps the one most important tree species of the original climax forest on the area.

Because of its slow growth, scanty seed production, and large heavy fruits with seeds lacking effective dispersal mechanisms, it has lost ground to other kinds of trees as a result of the unnatural disturbances which have occurred.

It still dominates on rocky upper slopes that have north, east or west exposures and forms nearly pure stands in limited areas. Nearly all the larger trees of this species now present have been cut one or more times and have regenerated from stump sprouts. Seedlings and young saplings of this oak are scarce even in parts of the woodland where the species is most common. It is evident that reproduction is slow, at least under present conditions. On the lower hill slopes these oaks are scarce and scattered, but some of the largest are in such situations. Chestnut oak seems to be relatively resistant to drought.

In the summer of 1954 when elms, and especially black oaks of all sizes were dying in large numbers, the chestnut oaks growing among them showed little evidence of injury in mature trees and only a small percentage of mortality in saplings.

[Ill.u.s.tration: Fig. 5. Map of Reservation showing present distribution of chestnut oak (shaded). The species is not spreading and is thought to be largely confined to the area that was wooded before 1860. Except in minor details, s.h.a.gbark hickory conforms to the same distribution pattern on this area.]

Chestnut oak has a relatively slow growth rate. In 17 that were recorded, there were, on the average, 4.59 annual rings per inch of trunk diameter. Near Pigeon Lake, Miami County, Kansas, counts were obtained from five cut in 1952 from a virgin stand in a habitat similar to that on the Reservation. The five trees had trunk diameters of 16 to 25 inches and ranged in age from 65 to 183 years. Several still growing on the Reservation are larger and presumably are well over 100 years old.