Streamside Forests Research Articles

Channel adjustments to the removal of log steps: an experiment in a mountain stream

Fallen trees and their large debris often form log steps in small mountain streams, where they are incorporated into the hydraulic geometry. The hypothesis here was that these log steps take the place of gravel bars that otherwise would have been required for channel slope adjustment. In this experiment, the treated as well as the control stream were located in virgin mixed conifer forests and until the study began, no human activity had interfered with the natural developments. All log steps were removed from a stream and the formation of new log steps was prohibited by periodic removal of fallen trees and branches. Five years later, 74% of all removed log steps had been replaced by gravel bars, thus proving the hypothesis that increased bedload movement was required to offset the loss of log steps. Implications are that streamside forests should be managed so that they can provide a steady supply of debris for channel stability.

Importance of streamside forests to large rivers: The isolation of the Willamette River, Oregon, U. S. A., from its floodplain by snagging and streamside forest removal

Importance of streamside forests to large rivers: The isolation of the Willamette River, Oregon, U. S. A., from its floodplain by snagging and streamside forest removal

Waterborne nutrient budgets for the riparian zone of an agricultural watershed

Agroecosystems in the southeastern United States Coastal Plain typically have uplands in agriculture with mixed hardwood forests along the stream channels. This study determined the inputs and outputs of waterborne nutrients for the riparian forest ecosystem of an agricultural watershed. Quantities of phreatic groundwater and precipitation nutrient inputs and phreatic and surface nutrient outputs were determined during 1979. Based on input/output budgets, these streamside forests were shown to be effective in retaining N, P, Ca, and Mg. Partial conversion of the riparian forest to cropland was projected to increase NO 3-N and NH 4-N loads by up to 800%. Total replacement of riparian forest with crops would increase loads of all nutrients studied except organic N, DMRP, and total P. Land managers can maintain the nutrient filtering capacity of the streamside forest by selective harvesting of hardwoods and by maintaining the present hydrologic regime.

Microhabitats of Woodland Centipedes in a Streamside Forest

Microhabitat utilization among several centipedes in a midwestern streamside forest was examined by pitfall-trapping and hand-collecting during 1973 and 1974. The woodland centipedes reported here include floodplain species (Lamyctes fulvicornis Meinert 1868) and 12 upland species. The upland centipedes can be further categorized as soil centipedes, log-limited centipedes [Sonibius politus (McNeill 1887) and Geophilus vitattus (Rafinesque 1826)], litter centipedes [(Scolopocryptops sexspinosa Say 1821), Pokabius bilabiatus (Wood 1867) and Strigamia bothriopa Wood 1862)] and log-litter species that occur in both microhabitats. No significant relationships were found between centipede abundance and any environmental factor, and no temporal patterns in microhabitat utilization were apparent.

HICKORY CREEK DRY RESERVOIR: A COMPRAOMISE DESIGN FOR BOTH FLOOD CONTROL AND NATURAL AREA PROTECTION1

Abstract: The proposed Hickory and Spring Creeks Flood Control and Recreation Project of the Illinois State Division of Water Resources and the Will County Forest Preserve District is desinged to provide flood control for Joliet, Illinos, and areas of the watershed to the east of the city and to provide open‐space recreational land upstream from the Hickory Breek Dry Reservoir embankement. A viable forest ecosytem in the reservoir flood pool following construction is of major importance to the project. Factors of the environment influencing tree distribution and flood tolerance and a process for determining the best operational design to provide both flood control and the maintenance of a natural streamside forest ecosystem are described.

Dynamics of Litter Fall, Decomposition, and Incorporation in the Streamside Forest Ecosystem

The dynamics of the litter stratum of a streamside forest ecosystem in Illinois, USA, are described. Changes in litter fall, leaf decomposition, and soil organic matter content were determined in relation to time and to the coenocline of canopy species induced by the gradient of flood variables of the Sangamon River. Gradient variation in litter fall was determined during two years (Sept 1973-Aug 1974 and Sept 1974-Aug 1975) by litter-fall traps. Leaf litter decomposition and soil organic matter were measured during the 1974-1975 sampling year. Total litter fall ranged from a low measured in 1973-1974 in the flood plain of 520.8 g m 2 yrl to a high of 977.1 g m-2 yr-' measured in the upland during 1974-1975. Slower decomposition rates in the upland resulted in turnover rates exceeding one year. All leaf litter falling in the flood-plain section of the gradient was either decomposed or washed into the stream during flood during each year. Soil organic matter in the upland averaged 4.17% and showed an increase between autumn levels and those recorded after decomposition of leaf matter was nearly completed.

Vegetation Gradients in the Streamside Forest of Hickory Creek, Will County, Illinois

Vegetation Gradients in the Streamside Forest of Hickory Creek, Will County, Illinois

Gradient analysis of spider communities in a streamside forest

Species composition and diversity of a guild of wandering spiders was studied by pitfall trapping over an elevational gradient in an Illinois streamside forest. Differences in flooding frequency and their effect on the litter habitat (removal and/or compression) account for a majority of the variation in the number of species between elevations. Changes in spider communities with elevation over the flooding gradient are indicative of a transition from a harsh to a moderate environment: (1) increased abundance and species diversity; (2) decreased dominance of flood tolerant species accompanied by increased dominance of species with specialized microhabitats found in complex litter; (3) greater similarity in species composition between sites; and, (4) a change in species-abundance curves from a geometric series to a lognormal distribution. The influence of the flooding regime in regulating community structure of spiders is discussed. A multiple regression equation including flood frequency and litter depth as variables was used to predict the impact of altered flooding regimes (due to reservoir construction downstream) on spider diversity.

Phenological Patterns in the Trees of the Streamside Forest

Phenological Patterns in the Trees of the Streamside Forest

Size-Class Structure of Three Streamside Forests

Analysis of size-class distribution in three streamside forest stands in central Illinois shows close agreement of observed data with the negative power curve model of tree size-class distribution. However, examination of the size-class distribution of selected species reveals a number of deviations from the model. Most of the deviations from the model can be explained in terms of disease and land use.

The Litter Stratum in the Streamside Forest Ecosystem

The litter stratum of the streamside forest ecosystem in Robert Allerton Park, Piatt County, Illinois, is described in relation to biotic and environmental gradients resulting from the flooding regime of the Sangamon River. Composition, structure, and distribution of several components of the litter layer were determined at vertical increments of 0.304 m over an elevational gradient from near the river edge into upland, unflooded areas. A gradient of potential available energy source for decomposer organisms was determined from leaf litter components and caloric values. Special emphasis was placed on determining the relationship between the physical structure of the litter gradient and potential available habitat for litter-dwellin ginvertebrate populations and decomposer organisms.

SIZE-CLASS STRUCTURE OF THREE STREAMSIDE FORESTS.

Analysis of size-class distribution in three streamside forest stands in central Illinois shows close agreement of observed data with the negative power curve model of tree size-class distribution. However, examination of the size-class distribution of selected species reveals a number of deviations from the model. Most of the deviations from the model can be explained in terms of disease and land use.

Tree Stratum Composition and Distribution in the Streamside Forest

The woody vegetation of the streamside forest in Robert Allerton Park, Piatt Co., Illinois, is described in relation to the distribution of river level frequencies of the Sangamon River. The habitats most frequently flooded are dominated by Acer saccharinum. With decreasing flooding frequency, dominance is transferred to Celtis occidentalis and Quercus imbricaria. The areas experiencing no flooding are dominated by Q. alba. Changes in the vegetational structure of elevational increments of .304 m (1 ft) are discussed. The principle that communities change gradually along environmental gradients is illustrated in a vertical elevation of less than 4 m. INTRODUCTION With the current expanding need for water resources, many civil works contractors are rapidly harnessing rivers and streams with a continuing emphasis on the construction of dams and reservoirs. Increased importance is also now being given to the environmental quality of these areas, and this emphasis is expected to intensify in the future. The clash between these seemingly widely opposed philosophies can only be rationally dicussed, and reasonable alternatives suggested, if an understanding of the streamside ecosystem is sufficient to adequately predict the effects of proposed perturbations. Historically, efforts to increase production have received vastly more attention than efforts to measure and mitigate the damaging effects of modern society on our water, land and air resources. As a result, relatively little informations about the effects of dams and similar structures on the dynamics of streamside ecosystems is now available. If ecological changes resulting from water resource development are to be objectively determined, then parameters of the natural biophysical environment must receive added attention. Certainly the riparian forests of the Midwest have come under stress as the industrialization and urbanization of areas within the farm belt have intensified the need for water. Forests within tihe Peninsula section of the Oak-Hickory Forest region described by Braun (1967) are considered to be of three general types: bottomland forests which line most of the streams, upland forests occurring in the upland areas bordering the major rivers and streams, and those isolated timber areas within the prairie, the Prairie Grove forests. The Prairie Grove forests have been considered in some detail by Boggess (1964), Boggess and Bailey (1964) and Boggess and Geis (1966). The upland communities associated with river courses were considered to be older than the Prairie Groves (Boggess and Geis, 1967), as the drainage ways in the Illinois prairie were believed to have been the major migratory pathway for tree in-

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)