Mockernut Research Articles

Host Plants Used by Gypsy Moths Affect Survival and Development of the Parasitoid Cotesi melanoscela

The effects of short-term phenological changes in different tree species on development and survival of the gypsy moth parasitoid Cotesia melanoscela (Ratz.) are examined. Larvae stung by C. melanoscela and an unstung control group were allowed to develop on foliage from four tree species (red maple, mockernut hickory, American beech, and white oak) started on five different dates during a 16-d period after bud break. Survival of Cotesia larvae declined Significantly with start date on all four species; however, white oak supported high wasp survival for most of the period. Wasp development time also increased significantly with increasing start date on each species. Stung larvae suffered significantly higher mortality from causes other than wasp emergence than did control larvae. The implications for underestimating mortality attributable to parasite attack are discussed. In particular, C. melanoscela probably causes significantly greater mortality of gypsy moth larvae than estimated from parasite emergence.

Effects of Herbivory and Competition on Survival of Carya tomentosa (Juglandaceae) Seedlings

We tested the effects of predation, above-ground diffuse competition and belowground diffuse competition on the survival and growth of Carya tomentosa (Juglandaceae) seedlings in a five year oldfield bordering a mature forest. We planted eighty seedlings under cages, in pots or with surrounding vegetation tied back (in all combinations) to realize the treatments. We found that seedlings unprotected from herbivores suffered great mortality (i.e., survival < 10%). Seedlings planted away from the forest edge suffered significantly less predation than those closer to the forest. Seedlings often resprouted after browsing. Because only a few seedlings survived outside the cages, we focused on the caged seedlings to examine competition effects on seedling growth and survival. No significant differences were found in leaf, stem, root, and total biomass of surviving seedlings under any of the competition treatments. Insect herbivores affected 15% of the seedlings by removing 10% of their leaf area during the first year. In the second year, 30% had 1-10% damage to leaf tissue. No seedlings died due to invertebrate herbivores. Browsing by mammalian herbivores appears to be the primary factor determining woody seedling establishment patterns in seral oldfields.

Serotonin content of foods: effect on urinary excretion of 5-hydroxyindoleacetic acid

Using a highly specific radioenzymatic assay we determined the serotonin concentration in 80 types of foods. The following fruits had a high serotonin concentration (mean +/- SEM) expressed in micrograms/g weight: plantain 30.3 +/- 7.5; pineapple 17.0 +/- 5.1; banana 15.0 +/- 2.4; Kiwi fruit 5.8 +/- 0.9; plums 4.7 +/- 0.8; and tomatoes 3.2 +/- 0.6. Only nuts in the walnut or hickory family had a high serotonin concentration expressed in micrograms/g weight; butternuts 398 +/- 90; black walnuts 304 +/- 46; English walnuts 87 +/- 20; shagbark hickory nuts 143 +/- 23; mockernut hickory nuts 67 +/- 13; pecans 29 +/- 4; and sweet pignuts 25 +/- 8. Ingestion of these fruits and nuts resulted in an increase in urinary 5-hydroxyindoleacetic acid excretion with no change in platelet serotonin concentration. The above foods should not be eaten while a urine is being collected for 5-hydroxyindoleacetic acid analysis.

Seasonal Response of Woody Plants to Tebuthiuron Pellets

Pelleted tebuthiuron {N-[5-(1,1-dimethylethyl)-1,3,4-thiadiazol-2-yl]-N,N′-dimethylurea} was hand broadcast at 2.2 and 4.5 kg ai/ha every month for 2 yr on an area infested with live oak (Quercus virginianaMill. ♯4QUEVI), post oak (Q. stellataWangenh. ♯ QUESL), parsley hawthorn (Crataegus marshalliiEgglest. ♯ CSCMS), and yaupon (Ilex vomitoriaAit. ♯ ILEVO) on the Gulf Coast Prairie near Cordele, TX. Live oak, post oak, and parsley hawthorn trees were killed at most rates and dates of tebuthiuron application. Applications of 2.2 kg/ha of tebuthiuron killed 90% or more of the yaupon plants when it was applied in October and December 1975 and February, March, and June 1976 and less than 90% when applied at other dates. On another site, pelleted tebuthiuron was aerially applied at 2.2 and 4.5 kg/ha every 3 months during 1978 and 1979 in the Post Oak Savannah near Bryan, TX. At 2.2 kg/ha, tebuthiuron killed all post oak and 80% or more of the blackjack oak (Q. marilandicaMuechh.), yaupon, winged elm (Ulmus alataMichx. ♯ ULMAL), and mockernut hickory (Carya tomentosaNutt.) regardless of date treated. Tree huckleberry (Vaccinium arboreumMarsh.) killed by tebuthiuron when applied at 2.2 kg/ha ranged from 34% in July 1979 to 69% from application in February 1978. Application of 4.5 kg/ha of tebuthiuron killed 83% or more of the tree huckleberry when it was applied in January and April 1978 and January, April, July, and October 1979. Herbaceous plant cover usually increased by the second season.

Species Ordination of Upper Slope Oak-Hickory Stands of Southeastern Ohio

MCCARTHY, B. C., T. I. VIERHELLER, AND W. A. WISTENDAHL (Dept. Bot., Ohio Univ., Athens, Ohio, 45701). Species ordination of upper slope oak-hickory stands of southeastern Ohio. Bull. Torrey Bot. Club 111: 56-60. 1984.-Detrended correspondence analysis was used to analyze the variations in the distribution of tree species with respect to aspect in an upper slope oak-hickory community of the mixed mesophytic forest of southeastern Ohio. Intensive sampling within this restricted slope position minimized the heterogeneity of soil parent materials while maximizing aspect variation between stands. Aspect proved to be of predictive value in estimating species distribution patterns. Quercus spp. and Carya glabra were more abundant on south-facing slopes. Carya ovata appeared to be more closely associated with the mesic species of north-facing slopes. Carya tomentosa, however, exhibited a distribution pattern apparently independent of aspect.

RELATIONSHIP AMONG VESSEL DIAMETER, VESSEL FREQUENCY, AND SPACING OF PARENCHYMA BANDS IN WOOD OF CARYA TOMENTOSA NUTT., MOCKERNUT HICKORY

Vessel‐lumen diameter, vessel frequency, and spacing of concentric, tangential bands of parenchyma cells follow well defined trends across annual growth rings of Carya tomentosa Nutt., mockernut hickory. These cross‐ring cellular changes were correlated with each other to a considerable degree but not tightly linked. Vessel‐lumen diameter decreased in a strongly linear fashion, as a function of distance from the inner ring boundary. Distance between tangential, concentric bands of axial wood parenchyma cells also decreased across rings, but followed a less strongly linear trend. Vessel frequency decreased abruptly after the large‐pore zone and then increased to the outer ring boundary. Radial growth rate, as indicated by ring width, strongly influenced these trends. For all three cellular characteristics, the cross‐ring trend was abrupt in narrow rings and more gradual in wide rings. An anomalous ring of Carya tomentosa, and three similar rings of Carya glabra (Mill.) Sweet, showed a decrease in interband distance and then an abrupt increase followed by another decrease to the outer ring boundary, whereas vessel diameter remained small and uniform after an initial decrease. The three cellular characteristics were concluded to be under separate physiological controls, although growth rate seems to exert a considerable, parallel influence on them.

Relationship Among Vessel Diameter, Vessel Frequency, and Spacing of Parenchyma Bands in Wood of Carya tomentosa Nutt., Mockernut Hickory

Relationship Among Vessel Diameter, Vessel Frequency, and Spacing of Parenchyma Bands in Wood of Carya tomentosa Nutt., Mockernut Hickory

Seasonal Changes in Tissue Water Relations of Three Woody Species of the Quercus‐Carya Forest Type

Tissue water relations of white and northern red oaks and mockernut hickory were studied during the growing season of 1979. In all species, osmotic potentials at full saturation and turgor loss point decreased during the period of leaf maturation; subsequently, osmotic potential responded to soil moisture availability. Estimates of the bulk modulus of elasticity and the relative water content at the turgor loss point revealed that white oak possessed less elastic leaf tissue than did either northern red oak or hickory. The bulk leaf pressure potential associated with the initiation of stomatal closure was lower in white oak and hickory (0.2 MPa) than in northern red oak (0.4 MPa) and remained seasonally constant, while total leaf water potential associated with stomatal closure was lower during periods of drought as osmotic potential decreased. The drought—tolerating behavior of white oak is consistent with its frequent occurrence and success in xeric habitats. Northern red oak and mockernut hickory exhibited responses more typical of drought—avoiding species, which would result in sustained turgor—mediated processes essential for growth and high competitive ability at moderate moisture stresses characteristic of more mesic habitats.

Control of an Oak(Quercus)Complex with Herbicide Granules

Granule, and in some cases, tablet and ball formulations of bromacil (5-bromo-3-sec-butyl-6-methyluracil), dicamba (3,6-dichloro-o-anisic acid), picloram (4-amino-3,5,6-trichloropicolinic acid), karbutilate [tert-butylcarbamic acid ester with 3(m-hydroxyphenyl)-1,1-dimethylurea], and tebuthiuron {N-[5-(1,1-dimethylethyl)-1,3,4-thiadiazol-2-yl]-N,N′-dimethyl urea} were applied to three areas within 30 km of College Station in the Claypan Resource area of Texas. Woody species growing in the area included blackjack oak(Quercus marilandicaMuenchh.), post oak(Quercus stellataWangenh.), yaupon(Ilex vomitoriaAit.), winged elm(Ulmus alataMichx.), white ash(Fraxinus americanaL.), mockernut hickory(Carya tomentosaNutt.), and tree huckleberry(Vaccinium arboreumMarsh.). Granules were applied either broadcast or in rows at several intervals. Tebuthiuron was the most effective herbicide on oaks, winged elm, and white ash. Tebuthiuron and picloram were equally and most effective on yaupon, mockernut hickory, and tree huckleberry. Tebuthiuron + picloram at 2.2 + 2.2 kg/ha was the most effective herbicide treatment on huckleberry. However, a mixture of tebuthiuron + picloram (1:1 w/w) was usually no more effective than the same rate of tebuthiuron in the mixture applied alone. Tablet and ball formulations of karbutilate and tablet formulations of tebuthiuron were generally equally as effective as granules. Applications of picloram and tebuthiuron granules in rows 1.8, 3.0, 4.6, or 6.1 m apart gave control equal to broadcast applications except for picloram on yaupon. On yaupon all row spacing treatments of picloram were less effective than the broadcast treatment, whereas with tebuthiuron the 6.1-m spacing was least effective. Picloram and tebuthiuron granules applied in rows, approximately at 1.8-m intervals with a tractor, were as effective as granules applied by hand in straight rows.

Larval Diet and Adult Longevity in the Elm Spanworm 1

Studies of the effects of various natural larval diets on adult longevity of the elm spanworm, Ennomos subsignarius (Hubner), are reported. Adult males on all diets lived longer than adult females. No differences in longevity were found resulting from diets of either mockernut hickory and northern red oak, but diets of pignut hickory foliage increased adult longevity. The ability of the males to mate and remate and to disperse would be increased by larval feeding upon pignut hickory.

Accumulation of rare earths and circulation of cerium by mockernut hickory trees

Mockernut hickory (Carya tomentosa) trees accumulate the rare-earth elements in foliage in far greater concentrations than do other species on the same site (1350 ppm in ash, compared with less than 60 ppm by red maple, tulip tree, white oak, and black gum). Inoculation of hickory trees with,144Ce showed that this typical rare-earth element moves slowly through woody tissues, with only a small percentage of total-tree cerium lost annually by leaf abscission. Slow decomposition of hickory litter further limits losses of rare earths from the tree–soil system. These processes create centers of rare-earth concentration that perpetuate themselves, exemplifying the role of accumulator species in determining the distribution of elements within ecosystems.

Bromacil and Picloram under Southern Upland Hardwoods

Bromacil (5-bromo-3-sec-butyl-6-methyluracil) was much more effective in killing post oak (Quercus stellata Wangenh.) and blackjack oak (Q. marilandica Muenchh.) trees than 4-amino-3,5,6-trichloropicolinic acid (picloram) when applied to soil at 5.6 and 11.2 kg/ha in spots, bands, or by broadcasting. When applied at 5.6 kg/ha in bands or broadcast, picloram effected better crown reduction than bromacil on mockernut hickory (Carya tomentosa Nutt). Differences between rates and methods of applying bromacil were small. While bromacil was superior on the prevalent overstory species, post oak and blackjack oak, picloram excelled on the most numerous understory plants.

Forest Composition on Loessal and Non‐Loessal Soils in West‐Central Mississippi

Four forest communities related to obvious edaphic areas in west—central Mississippe were sampled. Communities on thick loess were dominated by Liquidambar Styraciflua, Tilia sp., Quercus nigra, Liriodendron Tulipifera, Quercus falacata var. pagadaefllia, ulmus americana and rubra, and Carya cordiformis; those on thin loess by Fagus grandifolia, Nyssa sylvatica, Quercus velutina, and Carya tomentosa. Upland communities on non—loessal soils were dominated by Pinus taeda, Pinus echinata, Quercus falcata var. falcata, and Quercus alba; bottom land communities by Liquidambar Styraciflua, Fagus grandifolia, and Pinus glabra. Plant communities on deep loess and creek bottom non—loess were most closely related by species composition. These communities were quite distinct from communities of the general region as described in the literature. Examination of physical, climatic, and weather data indicated that the principal environmental factor delimiting the communities was availability of water.

Composition of an Upland, Streamside Forest in Piatt County, Illinois

Oaks and hickories comprised 48% of the 224 trees per acre and 83% of the average stand basal area of 102 ft2 per acre in a 34-acre portion of the Robert Allerton Park, located on rolling uplands along the Sangamon River. Such sites were among the first to be invaded by woody species following glaciation. The well-developed GrayBrown Podzolic soils of the area reflect a longer period of forest occupancy than in the Groves which were characteristic of the Illinois Prairie Region. White oak (Quercus alba L.) and black oak (Q. velutina Lam.) were the leading dominants, followed in order of importance by red elm (Ulmus rubra Muhl.), pignut hickory (Carya glabra (Mill.) Sweet.), red oak (Quercus rubra L.), American elm (Ulmus americana L.), mockernut hickory (Carya tomentosa Nutt.), sugar maple (Acer saccharum Marsh.), white ash (Fraxinus americana L.), and shagbark hickory (Carya ovata (Mill.) K. Koch). INTRODUCTION East-central Illinois is located in the Grand Prairie division (Vestal, 1931) and the Prairie Peninsula section of the Oak-Hickory Forest region described by Braun (1950). The upland forests of eastcentral Illinois are considered to be of two general types: those occurring along the major streams and rivers, and those isolated from the main bodies of timber in Groves. Recent papers (Boggess and Bailey, 1964; Boggess, 1964; Boggess and Geis, 1966) have considered in detail the composition of the Grove forests. River systems were believed to have been the major migratory pathways of woody species into the Illinois prairie following glaciation (Gleason, 1923). Upland sites bordering these migration routes have therefore been occupied by forest vegetation for a longer period of time than the Groves. The greater degree of soil development on such sites in part substantiates a longer period of forest occupancy. This paper, fourth in a series describing the woody vegetation of natural areas owned by the University of Illinois, concerns the composition of an upland, streamside forest in Piatt Co., Illinois. DESCRIPTION OF THE AREA The 1,500-acre Robert Allerton Park is located along the Sangamon River 4 mi SW of Monticello in Piatt Co., Illinois, and has been owned by the University since 1946. About 50l% of the park is accessible to the public, while the remainder is maintained as a plant and animal reserve. The protected portion includes 437 acres of upland timber, predominantly oak-hickory in composition. In 1963 a natural area of 34 acres, located in the SE'4, Sec. 29, T18N, R5E, 3 PM (Long 88039'W; Lat 39059'N), was permanently established. The forest within this natural area is essentially in virgin condition. 89 This content downloaded from 207.46.13.114 on Thu, 26 May 2016 06:19:23 UTC All use subject to http://about.jstor.org/terms 90 THE AMERICAN MIDLAND NATURALIST 78(1) The experimental areia lies on the Cerro Gordo moraine overlooking the river to the northwest. The topography is that of a rolling upland, decreasing in elevation to the south. At the southern end of the area, the surface levels into a bottom formed by the Willow Branch, a tributary of the Sangamon River. Total relief within the area is about 40 ft (12 mi). SOILS The soils within the experimental area are developed in 1 to 5 ft of loess overlaying glacial till of Wisconsin age. A soil survey conducted by the Soil Conservation Service, and recent investigations by Bailey et al. (1964) and Soerianegara (1965) indicate that the major portion of the soils are well-developed Gray-Brown Podzolic soils. Loess depths range from a minimum of less than 15 inches in Miami silt loam, through Xenia and Russell silt loams with 15 to, 36 inches, to a maximum of 36 to 60 inches in Birkbeck and Manlove silt loams. Internal soil drainage reaches, a maximum in the well-drained profiles of Miami, Russell, and Manlove silt loams. Birkbeck and Xenia silt loams are moderately well drained. These soils are characterized by very dark brown (1OYR 2/2) to dark gray (tOYR 3.5/1) silt loam Al horizons, dark brown (tOYR 4/3) to dark yellowish brown (tOYR 4/4) A2 horizons, and welldeveloped silty clay loam B horizons. A detailed profile description of Russell silt loam, developed in 38 inches of loess over loam till, has been given by Bailey et al. (1964). Some of the important characteristics o'f this profile are given in Table 1. METHODS OF STUDY In 1963 the 34-acre (13.75 hectare) natural area was permanently divided into 50-meter square sample blocks (0.61776 acre). Partial blocks were also established to include as much of the uniform mateTABLE 1.-Selected properties of Russell Silt Loam (GrayBrown Podzolic, Typic Normudalf)

Taxonomy of the Pecan Scab Fungus

Pecan scab is caused by a fungus that for almost thirty years has been called Cladosporium effusum (Wint.) Demaree (1928). Originally, Winter (1885) described this species as Fusicladium effusum, but Demaree transferred it to Cladosporium primarily because the conidia may be produced in chains. The type specimen was collected on Carya alba, which is a synonym for either C. tomentosa Nutt. or C. ovata (Mill.) K. Koch. Three years later, Ellis and Langlois, in an article by Ellis and Everhart (1888), reported the occurrence of a similar fungus on living leaves of C. olivaeformis Nutt. [= C. illinoensis (Wang.) K. Koch]. Although they recognized that this new fungus was scarcely distinct from F. effusum, Ellis and Langlois distinguished it on the basis of its epiphyllous, maculicolous growth and darker hyphae, and named it F. caryigenum Ell. & Langl. Orton (1905) reported that F. caryigenum is identical with F. effusum Wint. Many years before C. effusum (Wint.) Demaree was used as the name for the pecan scab fungus, Berkeley and Curtis, in an article by Berkeley (1875), had described an altogether different fungus which they named C. effusum Berk. & Curt. The description was based on four specimens collected on hosts unrelated to Carya. These collections are now recognized as belonging in Cercospora (Chupp, 1953, pp. 356, 357). Nevertheless, C. effusum (Wint.) Demaree is a later homonym of C. effusum Berk. & Curt. and thus cannot be used as a name for the pecan scab fungus (cf. Lanjouw et al., International Code of Botanical Nomenclature, 1956, arts. 63, 64). This presents the necessity of selecting some other name for this fungus. The procedure necessarily involves re-examining the morphological relationships of the pecan scab organism. If it is found to be a Fusicladium, as originally presented, Winter's name may be accepted. If Demaree is correct in believing it to be a Cladosporium, consideration may be given to making a new combination based on F. caryigenum. However, this would be feasible only if F. caryigenum is found to be conspecific with C. effusum (Wint.) Demaree.

Carya alba proposed as Nomen ambiguum

Carya alba proposed as Nomen ambiguum

INVESTIGATIONS ON THE MORPHOLOGY AND COMPARATIVE HISTORY OF DEVELOPMENT OF FOLIAR ORGANS IV. THE PROPHYLL OF CARYA BUCKLEYI VAR. ARKANSAN A

In Carya Buckleyi var. arkansana Sarg., the outermost scale of axillary buds on normal spur or long shoots is sac-like in form and, except for a more or less prominent opening near the abaxial apex, completely embraces the inner organs of the bud (text figs. I, 4, 9). Since the axillary buds of many dicotyledons are provided with paired lateral prophylls 2 this sac-like prophyll of the black hickory is unusual and invites comparison with the characteristically addorsed prophyll of monocotyledonous buds. Apparently the earliest morphological interpretation of the prophyll of Carya was proposed by D611 (1848, p. 22 and fig. i8). He suggested that in Carya alba, the outer scale of the axKillary bud represents two inwardly fused Later, Casimir de Candolle (i862, pp. io-i2 and P1. I) in his memoir on the Juglandaceae, pointed out differences in the number, arrangement and character of the bud scales of Carya by the use of which he subsequently (I864, pp. I42-145) divided the genus into two sections. De Candolle emphasized the fact that members of the section Apocarya differ in the construction of their axillary buds as follows. In Caryca arnara (= C. cordiformis K. Koch) the buds possess paired lateral valvate prophylls. In Carya aquatica and Carya olivaeformis (= C. pecan Asch. and Gr.), however, de Candolle stated that the prophylls of lateral buds are fused together, forming a sheath.4 Apparently unaware of D611's (op. cit.) earlier work, de Candolle, failed to comment on the prophylls of members of the section Eucarya. However, the bud diagram given of Carya porcina (= C. glabra. Sweet) clearly shows that in this species, the outermost scale of the axillary bud has a tubular character.5