Visually Determined Soil Disturbance Classes Used as Indices of Forest Harvesting Disturbance

1998 ◽  
Vol 22 (4) ◽  
pp. 245-250 ◽  
Author(s):  
W. Michael Aust ◽  
James A. Burger ◽  
Emily A. Carter ◽  
David P. Preston ◽  
Steven C. Patterson

Abstract Visual estimates of soil and site disturbances are used by foresters, soil scientists, logging supervisors, and machinery operators to minimize harvest disturbances to forest sites, to evaluate compliance with forestry Best Management Practices (BMPs), and to determine the need for ameliorative practices such as mechanical site preparation. Although visual estimates are commonly used by field personnel, the actual relationships of visually determined soil disturbance classes to various soil physical properties and site characteristics have not been determined. The purpose of this investigation was to evaluate if visually determined soil disturbance classes are related to quantitative soil and site properties that are known to influence soil productivity and hydrologic function. Several types of quantitative data were evaluated within the soil disturbance classes:static data (bulk density, saturated hydraulic conductivity, total, capillary, noncapillary pore space, and soil roughness) and dynamic data (mechanical resistance, volumetric soil moisture, subsurface water table depth). All data were collected from a long-term forest productivity study located in the Coastal Plain of South Carolina. The study is a randomized complete block design with two harvest disturbance levels (wet-weather harvest vs. dry-weather harvest) and a maximum of five site soil disturbance (SD) classes. Disturbance classes included undisturbed (SD0), compressed but not rutted (SD1), rutted (SD2), deeply rutted (SD3), and churned (SD4). Analyses revealed that three static variables (soil bulk density, saturated hydraulic conductivity, macropore pore space) and two dynamic variables (depth of the subsurface water table and mechanical resistance) were significantly related to disturbance. Although undisturbed and compressed areas generally were affected less than the more severe disturbance classes, the three most severe disturbance classes, churned areas, deeply rutted areas, and rutted areas were not different from one another. Thus, it appears visual disturbances do not necessarily equate to site damage. The overall implications are that visually determined soil disturbance classes have merit as indices of some soil and site changes, but they should not be equated to soil damage categories. South. J. Appl. For. 22(4):245-250.

Agronomy ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1005 ◽  
Author(s):  
Lucia Toková ◽  
Dušan Igaz ◽  
Ján Horák ◽  
Elena Aydin

Due to climate change the productive agricultural sectors have started to face various challenges, such as soil drought. Biochar is studied as a promising soil amendment. We studied the effect of a former biochar application (in 2014) and re-application (in 2018) on bulk density, porosity, saturated hydraulic conductivity, soil water content and selected soil water constants at the experimental site in Dolná Malanta (Slovakia) in 2019. Biochar was applied and re-applied at the rates of 0, 10 and 20 t ha−1. Nitrogen fertilizer was applied annually at application levels N0, N1 and N2. In 2019, these levels were represented by the doses of 0, 108 and 162 kg N ha−1, respectively. We found that biochar applied at 20 t ha−1 without fertilizer significantly reduced bulk density by 12% and increased porosity by 12%. During the dry period, a relative increase in soil water content was observed at all biochar treatments—the largest after re-application of biochar at a dose of 20 t ha−1 at all fertilization levels. The biochar application also significantly increased plant available water. We suppose that change in the soil structure following a biochar amendment was one of the main reasons of our observations.


2004 ◽  
Vol 80 (5) ◽  
pp. 573-582 ◽  
Author(s):  
D G Maynard ◽  
J P Senyk

Ground-based forestry practices can negatively affect soil productivity by altering the physical, chemical, and biological properties of soil. The effect of soil disturbance on soil properties and tree growth was evaluated following single-pass hydraulic excavator and multiple-pass combined excavator and flexible track grapple skidder forwarding in four silvicultural systems treatments: Clearcut (CC), Green Tree Retention (GT), Patch Cut (PC), and Uniform Shelterwood (SW). The effectiveness of an excavator soil-rehabilitation technique (tilling) in decompacting skidtrails (i.e., reducing soil bulk density) and nutrient availability was also evaluated. Western hemlock (Tsuga heterophylla (Raf.) Sarg.) and amabilis fir (Abies amabilis Dougl. Ex. Forbes) seedlings were planted on undisturbed plots, within tracks and between tracks of skidtrails, and in rehabilitated trails within the four harvesting treatments in the spring of 1994. Seedling growth was measured after five growing seasons, and nutrient concentrations of current-year foliage were determined at the end of the fourth growing season. Seedling survival and growth was generally reduced by soil disturbances associated with skid-trails. Effects of disturbance on physical properties of soil (e.g., compaction, puddling) and disruption of drainage were the most likely causes. Nutrient deficiencies do not appear to be a factor. Nonetheless, nitrogen concentrations were lower in current-year foliage taken from rehabilitation treatments than from either undisturbed or skidtrail treatments. Effectiveness of soil rehabilitation varied. In well-drained deeper soils, tilling reduced soil bulk density to levels below those of undisturbed soils and, in the short-term (five years), improved tree growth. In wetter conditions, rehabilitation treatment decreased survival and growth of both species. Thus specific rehabilitation (tilling) prescriptions should not be universally applied across a landscape. Key words: Abies amabilis, Tsuga heterophylla, foliar analysis, soil bulk density, soil compaction, soil rehabilitation


Soil Research ◽  
1982 ◽  
Vol 20 (4) ◽  
pp. 295 ◽  
Author(s):  
DR Scotter ◽  
BE Clothier ◽  
ER Harper

A method of measuring, with minimal soil disturbance, the saturated hydraulic conductivity and sorptivity of field soil is presented and discussed. It involves measuring the steady-state infiltration of ponded water from two rings, of different radii, that have been lightly pressed into the soil surface. The method is based on Wooding's solution for steady infiltration from a shallow, circular pond. Criteria for selecting ring radii are discussed. Results for three field soils are found to give consistent values for the conductivity and sorptivity.


1986 ◽  
Vol 66 (4) ◽  
pp. 737-742
Author(s):  
J. A. MILLETTE ◽  
R. S. BROUGHTON

Monolith column construction and sampling procedures were described for organic soil profiles and used to measure the variation with depth of saturated hydraulic conductivity, bulk density and fiber content. The top 0.30 m of the organic soil was more permeable, had a greater bulk density and had a greater fiber content than the soil layer between 0.60 and 0.90 m from the soil surface. These columns can be used for correlations studies between physical properties and studies of the dynamic nature of the physical properties of organic soils. Key words: Saturated hydraulic conductivity, bulk density, fiber content, organic soil, monolith columns


Literature overview. The parameterization of hydrological models requires knowledge of the soil filtration properties. Generally, soil profiles are characterized by properties such as sand, silt and clay content, bulk density, organic carbon fraction or humus content, and no data on filtration properties are available. Ukrainian soil database, created in Geoecophysics of soil laboratory of National Scientific Center “Institute for Soil Science and Agrochemistry Researched named after O.N. Sokolovsky” (Laktionova et al., 2012), among other properties has extensive data on texture and bulk density for more than 2000 profiles, less on organic carbon content, and almost no data on saturated hydraulic conductivity (Ksat). The most probable ranges of Ksat for most types of Ukrainian soils are given in the Atlas of natural conditions and natural resources of the Ukrainian SSR (“Pochvenno-meliorativnoye rayonirovaniye. Masshtab 1:4000000,” 1978), however, the data doesn’t present Ksat for different textures inside one soil type. To fill this gap, the best solution is the applying of pedotransfer function (PTF). The purpose of this work is to synthesize the most realistic Ksat of the main soil groups of Ukraine, corresponding to a scale map of 1:2 500 000 (Krupskiy, 1977), as well as their genetic horizons, on the basis of calculated and experimental values available in the literature. Material and methods. Ten PTFs used in the study are based on regression equations (Cosby et al., 1984; Saxton & Rawls, 2006; Weynants et al., 2009; Wösten et al., 1999), decision tree (Tóth et al., 2015), or neural network (Zhang & Schaap, 2017). Ksat was estimated for 942 horizons of 171 profiles which represented all 40 soil groups (corresponding to the legend of 1:2 500 000 map) of Ukraine according to Dokuchaev classification. Results. Wösten and Rosetta3 PTFs are determined as the most relevant by comparing the calculated Ksat values with the available data of the bottom (horizons A2, B, C) and top (A0, A1) soil layers of Ukraine. In particular, they are relevant for widespread soils such as Soddy podzolic soils (WRB – Eutric podzoluvisols), dark gray podzolized soils (Phaeozems Albic), chernozems podzolized (Chernozems Chernic), chernozems southern (Chernozems Calcic), meadow-chernozemic soils (Phaeozems Haplic), dark chestnut and chestnut soils (Kastanozems Haplic and Kastanozems Luvic), meadow soils (Umbrisols Gleic, Fluvisols Dystrict, Fluvisols Eutryc, Leptosols Umbric), mountain soils (Cambisols), and top layer of Chernozems ordinary (Chernozems Chernic). Unfortunately, all ten PTFs underestimate 2-4 times Ksat of bottom layer of ordinary and typical chernozems (Chernozems Chernic) and overestimate 2-5 times for relatively impermeable horizons (< 2 mm/h). Conclusions. Based on the calculated and experimental values, the map of Ksat of the top and bottom soil layers was obtained. Sandy soils, common in Polissia, have the highest filtration rate. Ksat of loam and clay soils of forest-steppe and steppe can differ between different types by an order. The highest Ksat have soils with high structural properties (Chernozems Luvic, Chernozems Chernic). The lowest Ksat (0.2-3 mm/h) have Phaeozems Sodic, Solonetz, Solonchaks, Planosols Albic, and bottom layer of soddy manly gley (Arenosols Protic/ Haplic) and loamy soddy podzolic soils (Albeluvisols Umbric). The estimated values should be considered as the most probable because Ksat depends on landscape location of soil profile, tillage operations, and soil temperate. The results are acceptable to use in hydrological calculations and modeling.


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