Effect of forest drainage on the peat bulk density of pine mires in Finland

1998 ◽  
Vol 28 (2) ◽  
pp. 178-186 ◽  
Author(s):  
Kari Minkkinen ◽  
Jukka Laine

Drainage of peatlands for forestry causes the water level to draw down, which results in subsidence of peat surface and increased peat bulk density (Db). Later on, an accelerated rate of organic matter decomposition and the pressure of the growing tree stand further compacts the peat. We measured the peat Db (0-80 cm) in 180 undrained and 209 drained (ca. 60-year-old) peatland sites representing three nutrient levels of pine fens and five macroclimatic regions from southern to northern Finland. Db was affected by climatic conditions, nutrient status, and the tree stand volume of the site. Db was significantly higher in drained than in undrained sites in all regions and site types: the mean (±SD) Db in the whole material was 82 ± 23 kg ·m-3 for the undrained sites and 133 ± 22 kg ·m-3 for the drained sites. The increase in Db was significant in all regions down to a depth of 60 cm and in southern Finland, even deeper than 80 cm. When the increase in carbon concentration was taken into consideration, the average postdrainage increase in the Db of the 0-80 cm layer equalled the amount of carbon in the 54-cm layer in average undrained peat. As the reported subsidences of peat surface in forest drainage areas in Finland are usually below this limit, the carbon storage of peat is likely to increase after drainage.

2010 ◽  
Vol 40 (8) ◽  
pp. 1485-1496 ◽  
Author(s):  
Sakari Sarkkola ◽  
Hannu Hökkä ◽  
Harri Koivusalo ◽  
Mika Nieminen ◽  
Erkki Ahti ◽  
...  

Ditch networks in drained peatland forests are maintained regularly to prevent water table rise and subsequent decrease in tree growth. The growing tree stand itself affects the level of water table through evapotranspiration, the magnitude of which is closely related to the living stand volume. In this study, regression analysis was applied to quantify the relationship between the late summer water table depth (DWT) and tree stand volume, mean monthly summertime precipitation (Ps), drainage network condition, and latitude. The analysis was based on several large data sets from southern to northern Finland, including concurrent measurements of stand volume and summer water table depth. The identified model demonstrated a nonlinear effect of stand volume on DWT, a linear effect of Ps on DWT, and an interactive effect of both stand volume and Ps. Latitude and ditch depth showed only marginal influence on DWT. A separate analysis indicated that an increase of 10 m3·ha–1 in stand volume corresponded with a drop of 1 cm in water table level during the growing season. In a subsample of the data, high bulk density peat showed deeper DWT than peat with low bulk density at the same stand volume.


2000 ◽  
Vol 42 (9) ◽  
pp. 195-201 ◽  
Author(s):  
P. Andreasen ◽  
P. B. Mortensen ◽  
A. Stubsgaard ◽  
B. Langdahl

The stabilisation of a sludge-mineral soil mixture and a method to evaluate the state of stabilisation were investigated. The organic matter and nitrogen content are reduced up to 50% during a stabilisation process of three months under Danish climatic conditions. The stabilisation was shown to be an aerobic process limited by oxygen transport within the mixture. The degree of stabilisation was evaluated by oxygen consumption in a water suspension and the results showed that a stable product was achieved when oxygen consumption was stable and in the level of natural occurring aerobic soils (0.1 mgO2/(g DS*hr). The study thereby demonstrates that a stability of a growth media can be controlled by the oxygen consumption method tested.


Soil Research ◽  
1984 ◽  
Vol 22 (1) ◽  
pp. 81 ◽  
Author(s):  
DK Friesen ◽  
GJ Blair

Soil testing programs are often brought in disrepute by unexplained variability in the data. The deposition of dung and urine onto grazed pasture brings about marked variation in the chemical status of soils which contributes to this variability. A study was undertaken to compare a range of sampling procedures to estimate Colwell-P, Bray-1 P, bicarbonate K and pH levels in adjacent low and high P status paddocks. The sampling strategies used consisted of 75 by 50 m grids; whole and stratified paddock zig-zag and cluster (monitor plot) samplings. Soil test means for the various parameters did not vary among sampling methods. The number of grid samples required to estimate within 10% of the mean varied from 121 for Bray-1 P down to 1 for soil pH. Sampling efficiencies were higher for cluster sampling than for whole paddock zig-zag path sampling. Stratification generally did not improve sampling efficiency in these paddocks. Soil test means declined as sampling depth increased, but the coefficient of variation remained constant for Colwell-P and pH. The results indicate that cluster sampling (monitor plots) is the most appropriate procedure for estimating the nutrient status of grazed pastures. This sampling method enables a more accurate measure to be taken of the nutrient status of a paddock and should allow more reasonable estimates to be made of the temporal variations in soil test.


1986 ◽  
Vol 107 (1) ◽  
pp. 43-54 ◽  
Author(s):  
Lindsey Caird ◽  
W. Holmes

SUMMARYInformation on the total organic matter intake, concentrates supplied (C), live weight (LW), week of lactation (WL), milk yield (MY), herbage organic matter digestibility (HOMD), herbage mass, sward height (SHT) or herbage allowance (HAL) measured individually for 357 cows at one of three sites was assembled. Observed intake was compared with intakes predicted by existing intake equations and new prediction equations based on regression models or regression and least-squares constants were developed. Major factors affecting intake were MY, LW, WL, C and HAL or SHT. Although HOMD was correlated with intake, better predictions were obtained when HOMD was omitted. There were differences between sites possibly associated with differences in measurement techniques.The predictive value of some existing equations and new equations were tested against independent sets of data. A simple equation (A) based on MY and LW (Ministry of Agriculture, Fisheries and Food, 1975) gave satisfactory average predictions but the mean square prediction error (MSPE) was high. The equations of Vadiveloo & Holmes (1979) adjusted for bias gave a relatively low MSPE. The preferred new equations for grazing cattle included MY, LW, WL, C and HAL or SHT, and their MSPE were similar to or lower than for indoor equations.The discussion indicates that a simple equation (A) would give adequate predictions for farm planning. The more detailed equations illustrate the inter-relations of animal with sward conditions and concentrate allowances. Predicted intakes may deviate from actual intakes because of short-term changes in body reserves.


2008 ◽  
Vol 88 (5) ◽  
pp. 761-774 ◽  
Author(s):  
J. A. P. Pollacco

Hydrological models require the determination of fitting parameters that are tedious and time consuming to acquire. A rapid alternative method of estimating the fitting parameters is to use pedotransfer functions. This paper proposes a reliable method to estimate soil moisture at -33 and -1500 kPa from soil texture and bulk density. This method reduces the saturated moisture content by multiplying it with two non-linear functions depending on sand and clay contents. The novel pedotransfer function has no restrictions on the range of the texture predictors and gives reasonable predictions for soils with bulk density that varies from 0.25 to 2.16 g cm-3. These pedotransfer functions require only five parameters for each pressure head. It is generally accepted that the introduction of organic matter as a predictor improves the outcomes; however it was found by using a porosity based pedotransfer model, using organic matter as a predictor only modestly improves the accuracy. The model was developed employing 18 559 samples from the IGBP-DIS soil data set for pedotransfer function development (Data and Information System of the International Geosphere Biosphere Programme) database that embodies all major soils across the United States of America. The function is reliable and performs well for a wide range of soils occurring in very dry to very wet climates. Climatical grouping of the IGBP-DIS soils was proposed (aquic, tropical, cryic, aridic), but the results show that only tropical soils require specific grouping. Among many other different non-climatical soil groups tested, only humic and vitric soils were found to require specific grouping. The reliability of the pedotransfer function was further demonstrated with an independent database from Northern Italy having heterogeneous soils, and was found to be comparable or better than the accuracy of other pedotransfer functions found in the literature. Key words: Pedotransfer functions, soil moisture, soil texture, bulk density, organic matter, grouping


Author(s):  
Kelsey Watts

Soils play a critical role to society as a medium that facilitates crop production and also contributes to the energy and carbon balance of the Earth System. Land-use change and improper land-use is one of the dominant factors affecting soil erosion and nutrient loss in soils. We examined the effects of land-use change on an Elmbrook clay/clay-loam soil on a farm in Ameliasburg on the northern part of Prince Edward County. Three cover types were examined: a sod field (established for over 10 years), a wheat field (part of a wheat/corn/soybean rotation for 30 years) and an undisturbed deciduous forest. Under each land-use type, cores to a depth of 40 cm were collected along three random 30 m transects (at 8, 16 and 24 m), then divided them into 10 cm increments, combining all similar depth increments along one transect. Soil quality was assessed by analyzing various soil physical and chemical properties. Bulk density of the soil was much higher (1.55 vs. 0.95 g/cm3) in both agricultural ecosystems compared to the forest, but only in the 0-10 cm layer. Soil moisture at 60% water holding capacity was much greater for the forest than the sod and wheat soils. Soil pH was slightly lower in the forest compared to the sod and wheat fields. The sod and wheat fields showed losses of ~52% and ~53% organic matter, respectively, in contrast to the forested area. The greatest differences in organic matter and total carbon were found in the top 10 cm, likely due to the greater accumulation of litter at the ground surface in the forest compared to the agricultural sites. It appears that long-term (10 year) agricultural production has led to a decline in some, but not all, soil quality measures, particularly soil organic matter, bulk density and water holding capacity. These findings are consistent with much of the literature concerning the effects of land-use change on soil quality, and highlight the need to develop improved management systems to minimize losses in soil quality that can lead to declines in the productivity potential of soils over time.


Dairy farming is vulnerable to seasonal variable factors such as temperature, cold climatic conditions, and rainfall. These affect the production and reproduction traits of dairy animals. Seasonal variability also affects the quantity of consumption and marketing of milk considerably. The study aimed to assess the seasonal fluctuation in milk production in Sivagangai District Cooperative Milk Producer Union Limited (SDCMPUL), Tamil Nadu. The study used secondary data. The milk production data were collected from SDCMPUL, Karaikudi, Tamil Nadu. The data covered the period from 2001-02 to 2020-21. The study used descriptive statistics, CAGR, and paired ‘t-test to determine the variation of milk production according to seasonal changes. The MS office - Excel software and SPSS software were used to analyse the data. The results revealed that the mean milk production of the lean and flush season was 2.46 and 2.30 lakh liters, and the CAGR of milk production in SDCMPUL, Tamil Nadu, during the period 2001-02 to 2020-21 was 5.65 percent, and it was 5.23 percent in lean season and 6.11 percent in the flush season while the growth rate of milk production during the lean and flush season was positive and was significant statistically. It was found that the quantity of milk production was higher in the lean season than a flush season; however, the variability of milk production was more in the flush season than in the lean season.


2003 ◽  
Vol 34 (4) ◽  
pp. 361-386 ◽  
Author(s):  
L. Sipelgas ◽  
H. Arst ◽  
K. Kallio ◽  
A. Erm ◽  
P. Oja ◽  
...  

The main objective of the present study is to test various methods for describing the absorption spectra of coloured dissolved organic matter (CDOM) and to determine the numerical values of some optical parameters of CDOM in lakes with diverse water quality. First, the parameters of an exponential model in different spectral intervals were determined. In addition, the suitability of some other models for the approximation of CDOM spectra was estimated. Specific absorption coefficients of CDOM were calculated from the absorption coefficients and dissolved organic carbon (DOC) concentrations. The experimental initial data were differences between spectral attenuation coefficients of filtered and distilled water. Two datasets were used: 1) for 13 Estonian and 7 Finnish lakes (altogether 404 spectra between 350 and 700 nm) measured by the Estonian Marine Institute (EMI); 2) for 10 Finnish lakes (73 spectra) measured by the Finnish Environment Institute (FEI). The spectra of CDOM absorption coefficients (aCDOM) were calculated from experimental data taking into account the correction due to scattering properties of colloids in the filtered water. The total content of CDOM in natural waters of Estonian and Finnish lakes was expressed by means of aCDOM at the wavelength of 380 nm. It varied significantly, from 0.71 to 19.5 m−1, the mean value (of all the investigated lakes) being around 6.6 m−1. Slopes of the exponential approximation varied widely, from 0.006 to 0.03 nm−1. Averaged over all lakes values of slope for the interval 380-500 nm obtained from the EMI dataset are close to those obtained from the FEI dataset: from 0.014 nm−1 (without correction) to 0.016-0.017 nm-1 (with different types of correction). These results are in good correspondence with most published data. Attempts to describe the spectra in the region of 350-700 nm by means of hyperexponential functions (∽ exp(-αλη)) show that: (1) η < 1 (in the case of traditional exponential approximation η = 1); (2) a promising idea is to seek the best fit only for wavelengths λ > λ1, where λ1 will be chosen taking into account the real shape of aCDOM spectra. The mean value of the specific absorption coefficient (a*CDOM) at the wavelength 380 nm obtained in this study (0.44 L mg−1 m−1) is close to the values published in the literature, if we assume that a*CDOM (380) is calculated using the data of dissolved organic matter (DOM). The optically non-active fraction of DOM in our study was high and therefore a*CDOM (380) was considerably higher (1.01 L mg−1 m−1) than a*CDOM (380). The results of the present work could be used in the modeling of underwater light field as well as in the interpretation of radiation measurements and optical remote sensing results.


1987 ◽  
Vol 67 (4) ◽  
pp. 747-763 ◽  
Author(s):  
M. A. NAETH ◽  
A. W. BAILEY ◽  
W. B. McGILL

A study was conducted in Solonetzic mixed prairie of southern Alberta to evaluate and determine the longevity of selected ecosystem responses to pipeline installation. Five adjacent natural gas pipelines on a series of rights-of-way (ROW) were studied at three sites. The lines, which were installed in 1957, 1963, 1968, 1972 and 1981, had diameters of 86, 86, 91, 107 and 107 cm, respectively. Soils were analyzed for particle size distribution, bulk density, pH, electrical conductivity, ion composition, and organic matter content. It was concluded that pipeline construction in Solonetzic mixed prairie range-land initially tended to improve surface soil chemical and physical properties compared to blowouts, but reduced soil quality in vegetated native prairie. Surface bulk density increased to 1.3–1.6 Mg m−3 from an undisturbed density of 0.9–1.0 Mg m−3. Increased densities were evident to 55 cm in all 1981 transects except the trench where subsurface densities were reduced. Chemical changes were associated with reduced organic matter and increased salts at the surface. On the basis of differences between the various ages of pipelines (1981, youngest; 1957, oldest) there was evidence for greater amelioration of chemical changes than of physical disturbances over time. The time needed to restore half the lost organic matter was estimated to be approximately 50 y. Key words: Pipeline, Solonetzic soil, rangeland (native), soil chemistry, bulk density, reclamation


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