A regional paleolimnological assessment of the impact of clear-cutting on lakes from the west coast of Vancouver Island, British Columbia

2001 ◽  
Vol 58 (3) ◽  
pp. 479-491 ◽  
Author(s):  
Kathleen Laird ◽  
Brian Cumming ◽  
Rick Nordin
Keyword(s):  
Organic Matter ◽  
Species Composition ◽  
West Coast ◽  
Forest Harvesting ◽  
Diatom Species ◽  
The West ◽  
Clear Cutting ◽  
Before And After ◽  
The Impact ◽  
Reference Lakes

The impact of forest harvesting on lakes within the temperate rainforest on the west coast of Vancouver Island was examined in a paleolimnological study of four lakes that had 35–92% of their watersheds progressively clear-cut over a period of 15–30 years (impact lakes) and four lakes that had experienced little or no known anthropogenic disturbance in their watersheds (reference lakes). Changes in diatom species composition and percent organic matter in the 210Pb-dated sediment cores were compared over the last 100 years in each of the impact lakes before and after the onset of forest harvesting, which began in 1950, and before and after 1950 in the four reference lakes. Only one impact lake showed significant changes in percent organic matter. Significant changes (p < 0.05) in species composition following forest harvesting were detected in all four impact lakes and in one of the four reference lakes. However, the changes in diatom species composition following clear-cutting in the impact lakes were small, with changes in the relative abundance of the most common species being maximally 20%, but more typically 3–10%.

A regional paleolimnological assessment of the impact of clear-cutting on lakes from the central interior of British Columbia

2001 ◽  
Vol 58 (3) ◽  
pp. 492-505 ◽  
Author(s):  
Kathleen Laird ◽  
Brian Cumming
Keyword(s):  
British Columbia ◽  
Organic Matter ◽  
Species Composition ◽  
Sediment Cores ◽  
Forest Harvesting ◽  
Diatom Species ◽  
Clear Cutting ◽  
Before And After ◽  
The Impact ◽  
Reference Lakes

The impact of forest harvesting on lakes within the central interior of British Columbia was examined in a paleolimnological study of six lakes that had 28–82% of their watersheds clear-cut (impact lakes) and four lakes that had experienced no logging in their watersheds (reference lakes). Changes in diatom species composition and percent organic matter in 210Pb-dated sediment cores were compared over the last 80 years in each of the impact lakes before and after the onset of forest harvesting and, in the reference lakes, before and after 1960 (the average onset of logging in five of the six impact lakes) and before and after 1975 (the onset of logging in one impact lake). Significant changes in species composition of diatoms following forest-harvesting activities were detected in four of the impact lakes and three of the reference lakes; however, the changes in diatom species composition were small, with changes in the relative abundance of the most common species being at most 11%. Significant increases in the percent organic matter after 1960 were found in one impact lake and three reference lakes; again these changes were small, with increases of 2–5%.

Changes in soil quality following humping/hollowing and flipping of pakihi soils on the West Coast, South Island New Zealand

2007 ◽  
pp. 265-270 ◽  
Author(s):  
S.M. Thomas ◽  
M.H.Beare C.D. Ford ◽  
V. Rietveld
Keyword(s):  
Organic Matter ◽  
Soil Quality ◽  
West Coast ◽  
Land Development ◽  
Hot Water ◽  
Limited Information ◽  
The West ◽  
Organic Matter Quality ◽  
Pasture Production ◽  
Soil C

Humping/hollowing and flipping are land development practices widely used on the West Coast to overcome waterlogging constraints to pasture production. However, there is very limited information about how the resulting "new" soils function and how their properties change over time following these extreme modifications. We hypothesised that soil quality will improve in response to organic matter inputs from plants and excreta, which will in turn increase nutrient availability. We tested this hypothesis by quantifying the soil organic matter and nutrient content of soils at different stages of development after modification. We observed improvements in soil quality with increasing time following soil modification under both land development practices. Total soil C and N values were very low following flipping, but over 8 years these values had increased nearly five-fold. Other indicators of organic matter quality such as hot water extractable C (HWC) and anaerobically mineralisable N (AMN) showed similar increases. With large capital applications of superphosphate fertiliser to flipped soils in the first year and regular applications of maintenance fertiliser, Olsen P levels also increased from values

scholarly journals Droperidol dropped; consultants not consulted

2003 ◽  
Vol 27 (08) ◽  
pp. 301-304
Author(s):  
Gavin Reid ◽  
Mark Hughson
Keyword(s):  
Questionnaire Survey ◽  
Clinical Care ◽  
Postal Questionnaire ◽  
Clinical Implications ◽  
The West ◽  
Abrupt Withdrawal ◽  
Before And After ◽  
Adequate Evaluation ◽  
Psychiatric Profession ◽  
The Impact

Aims and Method We conducted a postal questionnaire survey of the practice of rapid tranquillisation among 215 consultant psychiatrists in the West of Scotland, before and after the withdrawal of droperidol by the manufacturer. Results One hundred and eighty questionnaires (84% of those sent) were returned. Droperidol had been used extensively, often combined with lorazepam, for rapid tranquillisation. The main replacement suggested for droperidol was haloperidol. About half of the respondents to our survey chose to comment on the withdrawal of droperidol. More than half of the comments were unfavourable, including lack of an adequate replacement and lack of consultation with the psychiatric profession. Clinical Implications The abrupt withdrawal of droperidol, partly for commercial reasons, was regrettable. There was no time for an adequate evaluation of possible replacement medications and a lack of consultation with the profession regarding the impact on clinical care.

scholarly journals ENSO and Wintertime Extreme Precipitation Events over the Contiguous United States

2008 ◽  
Vol 21 (1) ◽  
pp. 22-39 ◽  
Author(s):  
Siegfried D. Schubert ◽  
Yehui Chang ◽  
Max J. Suarez ◽  
Philip J. Pegion
Keyword(s):  
United States ◽  
West Coast ◽  
Extreme Precipitation ◽  
East Coast ◽  
Daily Precipitation ◽  
Precipitation Variability ◽  
The West ◽  
Extreme Precipitation Events ◽  
The Impact ◽  
Precipitation Events

Abstract In this study the authors examine the impact of El Niño–Southern Oscillation (ENSO) on precipitation events over the continental United States using 49 winters (1949/50–1997/98) of daily precipitation observations and NCEP–NCAR reanalyses. The results are compared with those from an ensemble of nine atmospheric general circulation model (AGCM) simulations forced with observed SST for the same time period. Empirical orthogonal functions (EOFs) of the daily precipitation fields together with compositing techniques are used to identify and characterize the weather systems that dominate the winter precipitation variability. The time series of the principal components (PCs) associated with the leading EOFs are analyzed using generalized extreme value (GEV) distributions to quantify the impact of ENSO on the intensity of extreme precipitation events. The six leading EOFs of the observations are associated with major winter storm systems and account for more than 50% of the daily precipitation variability along the West Coast and over much of the eastern part of the country. Two of the leading EOFs (designated GC for Gulf Coast and EC for East Coast) together represent cyclones that develop in the Gulf of Mexico and occasionally move and/or redevelop along the East Coast producing large amounts of precipitation over much of the southern and eastern United States. Three of the leading EOFs represent storms that hit different sections of the West Coast (designated SW for Southwest coast, WC for the central West Coast, and NW for northwest coast), while another represents storms that affect the Midwest (designated by MW). The winter maxima of several of the leading PCs are significantly impacted by ENSO such that extreme GC, EC, and SW storms that occur on average only once every 20 years (20-yr storms) would occur on average in half that time under sustained El Niño conditions. In contrast, under La Niña conditions, 20-yr GC and EC storms would occur on average about once in 30 years, while there is little impact of La Niña on the intensity of the SW storms. The leading EOFs from the model simulations and their connections to ENSO are for the most part quite realistic. The model, in particular, does very well in simulating the impact of ENSO on the intensity of EC and GC storms. The main model discrepancies are the lack of SW storms and an overall underestimate of the daily precipitation variance.

scholarly journals Impact of treated sewage on meiobenthic nematodes: a case study from the Tunisian Refining Industries Company

2022 ◽  
Vol 82 ◽  
Author(s):  
A. Hedfi ◽  
M. Ben Ali ◽  
A. Noureldeen ◽  
H. Darwish ◽  
T. Saif ◽  
...  
Keyword(s):  
Organic Matter ◽  
Environmental Parameters ◽  
The Other ◽  
Treated Sewage ◽  
Before And After ◽  
Bizerte Bay ◽  
De Man ◽  
The Impact

Abstract The main objective of the current study was to assess the impact of the water taken from the ‘Tunisian Refining Industries Company’ on meiobenthic nematodes, before and after a series of treatments in decantation basins followed by its discharge in Bizerte bay, Tunisia. The comparison of environmental parameters of the two types of water was clearly indicative of an improvement in the quality of treated waters after a significant reduction in their loads in hydrocarbons. Overall, the water retained a good quality after being treated by ‘Tunisian Refining Industries Company’ before discharge in the sea. At the end of the experiment, differential responses were observed according to the richness of sediment in organic matter and hydrocarbons. Thus, it was apparent that the nematode assemblage exposed to the treated waters was closer to controls and associated to higher values of abundance, than that under untreated ones. It was also assumed that the species Microlaimus honestus De Man, 1922, Paramonohystera proteus Wieser, 1956 and Cyartonema germanicum Juario, 1972 are sensitive bioindicators of bad environmental statues and of hydrocarbon presence in the environment. On the other hand, Metoncholaimus pristiurus (Zur Strassen, 1894) Filipjev, 1918 would rather be classified as a positive bioindicative species of this type of pollutants.

scholarly journals Impact of forest harvesting on water quality and fluorescence characteristics of dissolved organic matter in eastern Canadian Boreal Shield lakes in summer

2015 ◽  
Vol 12 (23) ◽  
pp. 6999-7011 ◽  
Author(s):  
P. Glaz ◽  
J.-P. Gagné ◽  
P. Archambault ◽  
P. Sirois ◽  
C. Nozais
Keyword(s):  
Water Quality ◽  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Forest Harvesting ◽  
Spectroscopic Techniques ◽  
Clear Cutting ◽  
Fluorescence Measurements ◽  
Fluorescence Characteristics ◽  
Boreal Shield ◽  
Shield Lakes

Abstract. Forestry activities in the Canadian Boreal region have increased in the last decades, raising concerns about their potential impact on aquatic ecosystems. Water quality and fluorescence characteristics of dissolved organic matter (DOM) were measured over a 3-year period in eight eastern Boreal Shield lakes: four lakes were studied before, 1 and 2 years after forest harvesting (perturbed lakes) and compared with four undisturbed reference lakes (unperturbed lakes) sampled at the same time. ANOVAs showed a significant increase in total phosphorus (TP) in perturbed lakes when the three sampling dates were considered and in DOC concentrations when considering 1 year before and 1 year after the perturbation only. At 1 year post-clear cutting DOC concentrations were about 15 % greater in the perturbed lakes at ~ 15 mgC L−1 compared to 12.5 mgC L−1 in the unperturbed lakes. In contrast, absorbance and fluorescence measurements showed that all metrics remained within narrow ranges compared to the range observed in natural waters, indicating that forest harvesting did not affect the nature of DOM characterized with spectroscopic techniques. These results confirm an impact of forestry activities 1 year after the perturbation. However, this effect seems to be mitigated 2 years after, indicating that the system shows high resilience and may be able to return to its original condition in terms of water quality parameters assessed in this study.

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.

Sign in / Sign up

Export Citation Format

Share Document