scholarly journals Water and nitrogen processes along a typical water flowpath and streamwater exports from a forested catchment and changes after clear-cutting: a modelling study

2005 ◽  
Vol 9 (6) ◽  
pp. 657-674 ◽  
Author(s):  
A. Laurén ◽  
L. Finér ◽  
H. Koivusalo ◽  
T. Kokkonen ◽  
T. Karvonen ◽  
...  
Keyword(s):  
Buffer Zone ◽  
Organic N ◽  
Ground Vegetation ◽  
Spring Flood ◽  
Total N ◽  
Clear Cut ◽  
Clear Cutting ◽  
N Fluxes ◽  
Before And After ◽  
Eastern Finland

Abstract. A two dimensional model, FEMMA, to describe water and nitrogen (N) fluxes within and from a forested first-order catchment (Kangasvaara in Eastern Finland) was constructed by linking the most significant processes affecting the fluxes of water, ammonium, nitrate and dissolved organic nitrogen along a hillslope from the water divide to the stream. The hillslope represents the average flowpath of water in the catchment and the model was used to estimate the N fluxes for a catchment in eastern Finland before and after clear-cutting. The simulated results were in reasonable agreement with the nitrate, dissolved organic N and dissolved total N measurements from the study catchment and with other results in the literature. According to the simulations, the major sinks of N after clear-cutting were immobilisation by soil microbes, uptake by ground vegetation and sorption to soil. These sinks increased downslope from the clear-cut area, indicating the importance of an uncut buffer zone between the stream and the clear-cut area in reducing N exports. The buffer zone retained 76% of the N flux coming from the clear-cut area. Nitrification was a key process in controlling the N export after clear-cutting and N increases were mainly as nitrate. Most of the annual N export took place during the spring flood, when uptake of N by plants was minimal.

scholarly journals Influence of Plantation Establishment on Discharge Characteristics in a Small Catchment of Tropical Forest

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Siti Aisah Shamsuddin ◽  
Zulkifli Yusop ◽  
Shoji Noguchi
Keyword(s):  
Water Yield ◽  
Plantation Establishment ◽  
Forest Plantation ◽  
Small Catchment ◽  
Forested Catchment ◽  
Clear Cut ◽  
Clear Cutting ◽  
Before And After ◽  
Hopea Odorata ◽  
The Impact

A study was conducted on the impact of forest clearance on discharge from newly established Hopea odorata plantations catchment (14.4 ha). The stands were two years old when this study commenced in year 2006 and the data collection was carried out for two years. The forested catchment (C3) was clear-cut during the preparation of the forest plantation and catchment C1 was left undisturbed. Discharge and rainfall were measured continuously for two years. The discharge measured from years 1997 to 2003 was used also to determine the water yield before and after forest clear-cut. This study showed that the plantation catchment is more responsive to storm with higher total water yield than in the forested catchment. The effect of forest clear cutting to discharge was clearly shown by the increment in the amount following the clear-cut activities and time taken for the recovery of the discharge back to its original state was almost three years. The peak discharge in C3 also was affected in which the biggest change was obtained during the forest clear-cutting period compared with during calibration and after clearing periods. This study is useful as basis for improving the existing guidelines on forest plantation establishment.

Changes in bacterial populations in a clear-cut beech forest soil planted with spruce

1983 ◽  
Vol 29 (6) ◽  
pp. 644-648 ◽  
Author(s):  
Thu Kauri
Keyword(s):  
Organic Matter ◽  
Soil Bacteria ◽  
Forest Type ◽  
Beech Forest ◽  
Ground Vegetation ◽  
Soil Environment ◽  
Bacterial Populations ◽  
Clear Cut ◽  
Clear Cutting ◽  
Multipoint Method

A beech forest after clear-cutting was replanted with spruce. To study how this perturbation affected soil bacteria and their physiological capabilities, an investigation was undertaken 4 years after the change of forest type. Compared with an earlier study in the beech forest, from 1972 to 1975, conducted immediately before clear-cutting, bacterial numbers in the young spruce plantation had increased; an exception was the upper layer (A00), where the numbers decreased. The population densities of bacteria decomposing xylan, pectin, starch, cellulose, and chitin were estimated by a direct multipoint method. The numbers of bacteria in all the physiological groups studied were higher in 1979–1980, with the same exception as before (A00). The greatest changes occurred in the upper horizons. There were considerable changes in the soil environment after the former beech litter fall ceased; the forest floor became more exposed, and the ground vegetation changed. Changes took place in soil properties, such as organic matter and pH. A slight increase in pH was observed in all horizons except in A00, and organic matter increased in two of the horizons (A01/A1; A1).

scholarly journals Effects of clear-cutting and wildfires on succession of ground beetle (Coleoptera: Carabidae) assemblages on the east slopes of the Rocky Mountains

2019 ◽  
Vol 2 ◽  
Author(s):  
Vincent Del Bel Belluz ◽  
David Langor ◽  
Jari Niemelä ◽  
John Spence
Keyword(s):  
Ground Beetle ◽  
Mineral Soil ◽  
Basal Area ◽  
Species Assemblages ◽  
Ground Vegetation ◽  
Clear Cut ◽  
Clear Cutting ◽  
Beetle Assemblages ◽  
Trees And Shrubs

We studied how carabid beetle assemblages in lodgepole pine stands have responded after clear-cut harvest and wildfires on an actively managed landscape ~20 km south of Hinton, Alberta, Canada. The work builds on and expands a previous study (Niemela et al. 1993) conducted 23-24 years earlier in many of the same stands sampled in the current study. Carabid species assemblages are compared along a chronosequence of stands ranging in age from 12 to 53 years after clear-cutting. Recovery of carabid assemblages toward pre-harvest structure in regenerating stands, as reflected in the 2013-14 data, appears to have progressed more rapidly than in equivalently aged stands from the earlier study. In addition, carabid species assemblages differed significantly between clear-cut and burned stands of comparable age in 2013-14, with assemblages of burned stands being more similar to the pre-harvest structure than in clear-cut stands. Ground vegetation, mineral soil cover and basal area of trees and shrubs were significantly correlated with structure of carabid species assemblages in young and old regenerating stands, suggesting that environmental and plant successional gradients drive patterns in carabid assemblages. However, assemblage differences between older burned and clear-cut stands indicate that the type of disturbance influences long-term carabid recovery. Relationships between these findings and issues related to conservation of biodiversity and climate change are discussed.

scholarly journals PERBAIKAN SIFAT FISIKA DAN KIMIA TANAH PADA LAHAN BEKAS TAMBANG INTAN DI CEMPAKA DENGAN METODE COMPOSTING BERBAHAN DASAR SAMPAH ORGANIK PASAR

2021 ◽  
Vol 7 (2) ◽  
Author(s):  
Siti Ayu Irnada ◽  
Rizqi Puteri Mahyudin ◽  
Muhammad Firmansyah
Keyword(s):  
Chemical Properties ◽  
Organic N ◽  
Soil Color ◽  
Total N ◽  
Organic C ◽  
Composting Process ◽  
Randomized Design ◽  
Before And After ◽  
C 50 ◽  
Physical And Chemical

Penelitian ini bertujuan untuk mengidentifikasi kondisi suhu, pH dan kelembapan pada bioremediasi metode composting, mengidentifikasi perubahan sifat fisika dan kimia tanah bekas tambang intan sebelum dan sesudah proses composting juga mengidentifikasi komposisi terbaik pada composting berbahan dasar sampah organik pasar sistem open windrow. Rancangan penelitian menggunakan Rancangan Acak Lengkap (RAL) dengan 4 perlakuan dan 3 ulangan. Perlakuan yang dimaksud yaitu A  (100% tanah) sebagai kontrol, B (25% tanah : 75% kompos), C (50% tanah : 50% kompos), D (75% tanah : 25% kompos). Hasil penelitian suhu, pH dan kelembapan keempat perlakuan selama proses bioremediasi dengan metode composting mengalami fluktuasi. Berdasarkan hasil uji T terdapat perbedaan nilai C-organik, N-total, Rasio C/N, KTK serta warna sebelum dan sesudah proses composting. Hasil Uji LSD 5% variasi komposisi terbaik yang mampu memperbaiki kualitas tanah tambang adalah variasi komposisi 25% tanah : 75% kompos.  Kata kunci: composting, C-organik, N-total, KTK, warna tanah. The purpose of this research is to identify the conditions of temperature, pH and moisture in composting method of bioremediation, identify changes in physical and chemical properties of diamonds before and after the composting process and also identify the best composition on composting made from market organic waste of the open windrow system. The research design used a Completely Randomized Design (CRD) with 4 treatments and 3 replications. The treatment referred to is A (100% soil) as control, B (25% soil: 75% compost), C (50% soil: 50% compost), D (75% soil: 25% compost) with the weight of each one treatment / 40 kg stack and 30 cm stack height. The results of the research of temperature, pH and moisture of the four treatments during the bioremediation process by composting method are fluctuated. Based on the results of the T test there are differences in the value of C-organic, N-total, C / N ratio, CEC and soil color before and after the composting process. LSD 5% test results of the best composition variations that can improve the quality of mine soil is a variation of the composition of 25% soil: 75% compost. Keywords: CEC, composting, organic C, soil color, total N.

Nitrate formation and movement before and after clear-cutting of a monitored watershed in central New Brunswick, Canada

1982 ◽  
Vol 12 (4) ◽  
pp. 922-930 ◽  
Author(s):  
H. H. Krause
Keyword(s):  
Soil Solution ◽  
Nitrate Nitrogen ◽  
Nitrogen Loss ◽  
Water Discharge ◽  
Main Stream ◽  
Continuous Sampling ◽  
Clear Cut ◽  
Clear Cutting ◽  
Soil Solutions ◽  
Before And After

A watershed of 391 ha, supporting tolerant hardwoods on elevated sloping portions and softwoods on low lying areas, was clear-cut in 1978. Nitrate nitrogen was monitored over 5 years before and 3 years after clear-cutting by periodic extraction of soil solution samples and continuous sampling of the brooks draining the cut and a similar control watershed. The brooks were gauged to determine water discharge. Before clear-cutting, nitrate nitrogen was not detectable for most of the time in soil solutions under softwood cover, but occurred commonly under hardwood cover with concentrations ranging upward to 4.7 mg/L. Nitrate nitrogen in the brooks varied from undetectable to 0.3 mg/L. After clear-cutting, nitrate nitrogen increased to maximum concentrations of 13.4 mg/L, in the soil solution under hardwood cover, and 1.6 mg/L, in the main channel of the brook. Soil solution nitrogen was not changed significantly by clear-cutting of softwood stands. The 3-year cumulative nitrogen loss attributable to clear-cutting was 19.1 kg/ha. Nitrate nitrogen in soil solutions, branch, and main stream indicated that disproportionately larger amounts of nitrogen were lost from the elevated and sloping portions of the watershed than from the lower lying areas.

scholarly journals Response of sedimentary processes to cyanobacteria loading

2015 ◽  
Author(s):  
Mindaugas Zilius ◽  
Rutger De Wit ◽  
Marco Bartoli
Keyword(s):  
Experimental Approach ◽  
Organic N ◽  
N Fixation ◽  
Atmospheric Nitrogen ◽  
Labile Organic Matter ◽  
Total N ◽  
Open Sea ◽  
N Fluxes ◽  
Benthic Microbial Community ◽  
N Compounds

<p>Sedimentation of pelagic cyanobacteria in dystrophic freshwater and oligohaline lagoons results in large inputs of labile organic matter (OM) to the benthos. We used an experimental approach to study the short-term impact of such phenomena on the benthic microbial community metabolism and on the nitrogen (N) fluxes across the sediment-water interface. We hypothesized an increase of respiratory activity, including N loss via denitrification and its recycling to the water column. Our results show that the incorporation within sediments of the settled bloom increases benthic bacterial activities. This is coupled to large DON and NH<sub>4</sub><sup>+</sup> effluxes, and to a comparatively smaller increase of N<sub>2</sub> production, while no significant effects were detected for the benthic fluxes of NO<sub>x</sub><sup>-</sup>. We constructed flow schemes for N compounds, which show that while denitrification was significantly stimulated by amending cyanobacterial biomass to the sediments, it represented less than 1% of total OM mineralization. Interestingly, we observed that total released nitrogen (DIN+DON+N<sub>2</sub> efflux) was dominated by DON, which contributed 75–80 % of the net N efflux, suggesting incomplete mineralization of OM. With the measured total N mobilization rate of about 15 mmol N m<sup>-2</sup> d<sup>-1</sup> it would take more than 4 months to regenerate the total organic N input to sediments (2031 mmol N m<sup>-2</sup>), which represents the post-bloom deposited particulate organic N. These results suggest limited losses to the atmosphere and slow diffusive recycling of N buried into sediments, mostly as DON. Such regenerated N may eventually be flushed to the open sea or sustain pelagic blooms within the estuarine environment, including cyanobacteria, with a negative feedback for further import of atmospheric nitrogen via N-fixation.</p>

Effect of variable-retention harvesting on soil nitrogen availability in boreal mixedwood forests

2006 ◽  
Vol 36 (11) ◽  
pp. 3029-3038 ◽  
Author(s):  
Lucie Jerabkova ◽  
Cindy E Prescott ◽  
Barbara E Kishchuk
Keyword(s):  
Nitrogen Availability ◽  
Nutrient Dynamics ◽  
Organic N ◽  
N Availability ◽  
Net N Mineralization ◽  
Mixed Stands ◽  
Clear Cut ◽  
Clear Cutting ◽  
Variable Retention ◽  
Microbial N

Clear-cut harvesting of forests may be associated with increased availability and losses of nitrogen (N), and variable-retention (VR) harvesting has been proposed as an environmentally acceptable alternative to clear-cutting. In boreal forests, however, harvesting has often not led to significant increases in N availability and it is thus important to assess whether variable retention practices are necessary and justifiable in such forests with respect to nutrient dynamics. We compared N availability in clear-cut and VR-harvested stands in the boreal mixedwood forest of northwestern Alberta. We measured soil concentrations of nitrate, ammonium, soluble organic N, and microbial N in uncut, 50% and 20% retention, and clearcuts of deciduous-dominated, coniferous-dominated, and mixed stands 4 years after harvesting. There was little apparent effect of harvesting on N availability in all forest types. Nitrate, ammonium, and microbial N concentrations and net N mineralization and nitrification rates were similar in clearcuts and uncut forests and there was no threshold effect of harvesting on N availability. Soluble organic N concentrations were lower in coniferous and mixed clearcuts than in uncut stands on only one occasion. Clear-cut harvesting in itself does not appear to lead to long-lasting increased N availability and losses in boreal mixedwoods. Adoption of VR harvesting in these ecosystems may not be justified on the grounds of reducing changes in N availability when compared with clear-cutting.

Succession of understory vegetation in managed and seminatural Scots pine forests in eastern Finland and Russian Karelia

2005 ◽  
Vol 35 (6) ◽  
pp. 1422-1441 ◽  
Author(s):  
Anneli Uotila ◽  
Juha-Pekka Hotanen ◽  
Jari Kouki
Keyword(s):  
Forest Management ◽  
Scots Pine ◽  
Prescribed Burning ◽  
Understory Vegetation ◽  
Tree Canopy ◽  
Ground Vegetation ◽  
Tree Seedlings ◽  
Dwarf Shrubs ◽  
Clear Cutting ◽  
Eastern Finland

The aim of this study was to compare the understory vegetation in chronosequences representing seminatural and managed Scots pine (Pinus sylvestris L.) forests on dryish heaths of the Vaccinium type. The data represent the middle boreal vegetation zone and were collected in eastern Finland and the Dvina area of Karelia, on both sides of the border between Finland and the Russian Federation. Species diversity and the coverage of the various life-form groups (ground lichens, mosses, liverworts, grasses, herbs, dwarf shrubs, and tree seedlings) were used to analyse the properties of the ground vegetation over the succession from open forest land to closed forest communities. The clearest differences in diversity between the seminatural forests mainly influenced by fire and managed forests occurred in the early stages of succession. Forest management appeared to increase the species richness at the beginning of succession. The seminatural stands were rich in Cladonia lichens and dwarf shrubs up until tree canopy closure; however, the abundance of mosses was lower in the seminatural stands. Forest management favoured an abundance of grasses, notably Deschampsia flexuosa, which was common after clear-cutting. The use of prescribed burning in silviculture could result in more natural vegetation succession dynamics in managed stands.

Using advanced control, post-denitrification and equalisation to improve the performance of a submerged filter

2000 ◽  
Vol 41 (4-5) ◽  
pp. 177-184 ◽  
Author(s):  
K.H. Sørensen ◽  
D. Thornberg ◽  
K.F. Janning
Keyword(s):  
Energy Consumption ◽  
Total N ◽  
Control Loops ◽  
Effluent Quality ◽  
Advanced Control ◽  
Before And After ◽  
And Control ◽  
Side Flow ◽  
Configuration Control ◽  
Control Post

In 1998, the capacity of the BIOSTYR® submerged biofilter at Nyborg WWTP was extended from 48,000 PE to 60,000 PE including advanced sensor based control, post-denitrification in BIOSTYR® and equalization of side flows. The existing configuration with 8 BIOSTYR® DN/N cells is based on pre-denitrification and an internal recirculation of 600–800%. The extended plant comprises 7 BIOSTYR® DN/N cells with 50–225% recirculation followed by 3 BIOSTYR DN cells for post-denitrification. The advanced control loops include blower control, control of the number of active cells (stand-by), automatic switch to high load configuration, control of the side flow equalization, control of the internal recirculation and control of the external carbon source dosing. In this paper, the achieved improvements are documented by comparing influent and effluent data, methanol and energy consumption from comparable periods before and after the extension. Although the nitrogen load to the plant was increased by 20% after the extension, the effluent quality has improved significantly with a reduction of Total-N from 7–8 mg/l to 3–4 mg/l. Simultaneously, the methanol consumption has been reduced by more than 50% per kg removed nitrogen. The energy consumption remained constant although the nitrogen load was increased by 20% and the inflow by 80%.

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