scholarly journals Influence of mechanical site preparation on regeneration success of planted conifers in clearcuts in Fennoscandia – a review

Silva Fennica ◽  
2020 ◽  
Vol 54 (2) ◽  
Author(s):  
Ulf Sikström ◽  
Karin Hjelm ◽  
Kjersti Holt Hanssen ◽  
Timo Saksa ◽  
Kristina Wallertz
Keyword(s):  
Pinus Contorta ◽  
Survival Rates ◽  
Soil Surface ◽  
Site Preparation ◽  
Growth Effect ◽  
Mechanical Site Preparation ◽  
Temperature Sum ◽  
Disturbed Soil ◽  
Meta Analyses ◽  
Soil Inversion

In the Nordic countries Finland, Norway and Sweden, the most common regeneration method is planting after clearcutting and, often, mechanical site preparation (MSP). The main focus of this study is to review quantitative effects that have been reported for the five main MSP methods in terms of survival and growth of manually planted coniferous seedlings of Norway spruce ( (L.) Karst.), Scots pine ( L.) and lodgepole pine ( var. Engelm.) in clearcuts in these three countries. Meta analyses are used to compare the effects of MSP methods to control areas where there was no MSP and identify any relationships with temperature sum and number of years after planting. In addition, the area of disturbed soil surface and the emergence of naturally regenerated seedlings are evaluated. The MSP methods considered are patch scarification, disc trenching, mounding, soil inversion and ploughing. Studies performed at sites with predominately mineral soils (with an organic topsoil no thicker than 0.30 m), in boreal, nemo-boreal and nemoral vegetation zones in the three Fenno-Scandinavian countries are included in the review. Data from 26 experimental and five survey studies in total were compiled and evaluated. The results show that survival rates of planted conifers at sites where seedlings are not strongly affected by pine weevil ( L.) are generally 80–90% after MSP, and 15–20 percent units higher than after planting in non-prepared sites. The experimental data indicated that soil inversion and potentially ploughing (few studies) give marginally greater rates than the other methods in this respect. The effects of MSP on survival seem to be independent of the temperature sum. Below 800 degree days, however, the reported survival rates are more variable. MSP generally results in trees 10–25% taller 10–15 years after planting compared to no MSP. The strength of the growth effect appears to be inversely related to the temperature sum. The compiled data may assist in the design, evaluation and comparison of possible regeneration chains, i.e. analyses of the efficiency and cost-effectiveness of multiple combinations of reforestation measures.Picea abiesPinus sylvestrisPinus contortalatifoliaHylobius abietis

White spruce establishment in boreal Ontario mixedwood: 5-year results

1995 ◽  
Vol 71 (5) ◽  
pp. 633-638 ◽  
Author(s):  
R. F. Sutton ◽  
T. P. Weldon
Keyword(s):  
Picea Glauca ◽  
Relative Effectiveness ◽  
Survival Rates ◽  
Growing Season ◽  
White Spruce ◽  
Site Preparation ◽  
Mechanical Site Preparation ◽  
Growing Seasons ◽  
Silvicultural Treatments ◽  
Block Experiment

Five-year results of a study to evaluate the relative effectiveness of nine silvicultural treatments for establishing plantations of white spruce (Picea glauca [Moench] Voss) in boreal Ontario mixed-wood are presented. The experimental design provided three levels of mechanical site preparation (none, disk trenching, and toothed-blading) in all combinations with three kinds of chemical weed control (none, Velpar L© at the time of planting, and Vision© during the second growing season). A randomized block experiment using 0.8-ha plots and two replications was established in Oates Twp. in 1985 and repeated in adjacent Oswald Twp. in 1986. Bareroot white spruce was planted throughout. Four 25-tree sub-plots, located systematically from a random start, were established in each plot. White spruce performance was monitored for five years. Fifth-year survival rates averaged 34% and 84% without and with mechanical site preparation, respectively. Mean total heights after five growing seasons differed significantly (P < 0.01) by category of mechanical site preparation: teeth > trencher > none. Other criteria of performance showed the same pattern. Because of operational exigencies, the herbicide treatments were not applied as scheduled, which might account for the apparent ineffectiveness of those treatments in the particular circumstances of this study. Key words: Site preparation, disk trencher, Young's teeth, herbicides

scholarly journals Alternatives to broadcast burning in the northern interior of British Columbia: Short-term tree results

2000 ◽  
Vol 76 (2) ◽  
pp. 349-353 ◽  
Author(s):  
J. M. Kranabetter ◽  
D. Yole
Keyword(s):  
British Columbia ◽  
Pinus Contorta ◽  
High Elevation ◽  
Site Preparation ◽  
Foliar Nutrients ◽  
Short Term ◽  
Positive Role ◽  
North Central ◽  
Mechanical Site Preparation ◽  
Foliar Concentrations

We compared the growth and foliar nutrients of lodgepole pine and hybrid white spruce following mechanical site preparation treatments and broadcast burning in a high-elevation plantation in north-central British Columbia. After five years, the largest trees were found on the broadcast burn (44% increase over raw planting), followed by disc-trenching (26% increase), and then windrow piling (9% increase). Height increment was similarly significantly different between treatments after seven years. Equal increases in nitrogen, phosphorus, and sulphur foliar concentrations were found across all site preparation treatments compared to controls. Foliar nutrients alone, however, did not further explain the differences in tree productivity between site preparation treatments. The results demonstrated how some sites can benefit from site preparation, in the short-term at least, and also emphasized the positive role fire can have on forest productivity. Key words: mechanical site preparation, broadcast burning, Picea gluaca, Pinus contorta

Effects of mechanical site preparation and slash removal on long-term productivity of conifer plantations in Sweden

2019 ◽  
Vol 49 (10) ◽  
pp. 1311-1319
Author(s):  
Karin Hjelm ◽  
Urban Nilsson ◽  
Ulf Johansson ◽  
Per Nordin
Keyword(s):  
Pinus Contorta ◽  
Site Index ◽  
Site Preparation ◽  
Long Term Effects ◽  
Preparation Methods ◽  
Mechanical Site Preparation ◽  
Positive Effects ◽  
Negative Effect ◽  
Individual Trees

Mechanical site preparation is commonly used to increase survival and early growth of newly planted seedlings. Ideally, any early positive effects of site preparation should persist for a long time, but concerns have been raised as to whether intensive site preparation might have a negative effect on the long-term productivity of a stand. The present study was therefore designed to investigate the long-term effects of different site-preparation methods on productivity and determine any possible interactions with tree species and site fertility. In the 1980s, a randomized block experiment was established at sites throughout Sweden. Four site-preparation methods of various intensities were performed on different sites: (i) an untreated control, (ii) disc trenching, (iii) mounding, and (iv) ploughing. As a complementary treatment, slash was either retained or removed from some plots. Depending on soil moisture class, geographical position, and site index, Norway spruce (Picea abies (L.) Karst.), Scots pine (Pinus sylvestris L.), or lodgepole pine (Pinus contorta Douglas ex Loudon) were planted in pure stands. Growth variables such as height and diameter were measured during the first years after establishment. After about 30 years, these variables were remeasured at the level of individual trees. Overall, an increased production of the planted trees after site preparation was found. Neither intensive site preparation (such as ploughing) nor slash removal had any negative effect on the long-term productivity of these experimental stands.

Chemical and mechanical site preparation: effects on Pinus contorta growth, physiology, and microsite quality on grassy, steep forest sites in British Columbia

2003 ◽  
Vol 33 (8) ◽  
pp. 1495-1515 ◽  
Author(s):  
Suzanne W Simard ◽  
Melanie D Jones ◽  
Daniel M Durall ◽  
Graeme D Hope ◽  
Robert J Stathers ◽  
...  
Keyword(s):  
British Columbia ◽  
Forest Floor ◽  
Pinus Contorta ◽  
Aggregate Stability ◽  
Site Preparation ◽  
Preparation Methods ◽  
Growth Physiology ◽  
Mechanical Site Preparation ◽  
Forest Sites ◽  
Soil Temperatures

Site preparation alleviates the effects of pinegrass (Calamagrostis rubescens Buckl.) interference on conifers in British Columbia, but little is known about interference mechanisms and appropriate site preparation methods for steep slopes. In this study, lodgepole pine (Pinus contorta Dougl. ex Loud.) was planted in pinegrass controls and small (90 × 90 cm) and large (180 × 90 cm) patches where (i) only pinegrass was removed using glyphosate or (ii) both pinegrass and the forest floor were removed using an excavator. Treatments were replicated three times in east- and west-facing clearcuts and effects were followed for 9 years. Two-year pine survival was 78% in the control and >97% in large patches. All patch treatments improved pine growth, but it was greatest in large chemical patches during the initial 6 years and in both large patch treatments thereafter. Removal of the forest floor reduced foliar and soil nutrients, increased bulk density and soil water availability, decreased porosity and aggregate stability, and reduced ectomycorrhizal diversity and richness. These changes were not observed in chemical patches. All patch treatments increased soil temperatures and reduced frost relative to controls, but more so in large patches. Pinegrass can suppress early pine performance, and large chemical patches that retain the forest floor are best for relieving the multiple environmental stressors.

scholarly journals Bedding and Fertilization Ameliorate Effects of Designated Wet-Weather Skid Trails after Four Years for Loblolly Pine (Pinus taeda) Plantations

1998 ◽  
Vol 22 (4) ◽  
pp. 222-226 ◽  
Author(s):  
W. Michael Aust ◽  
James A. Burger ◽  
William H. McKee ◽  
Gregory A. Scheerer ◽  
Mark D. Tippett
Keyword(s):  
Pinus Taeda ◽  
Loblolly Pine ◽  
Water Movement ◽  
Block Design ◽  
Site Preparation ◽  
Site Productivity ◽  
Mechanical Site Preparation ◽  
Wet Weather ◽  
Four Levels ◽  
Study Sites

Abstract Wet-weather harvesting operations on wet pine fiats can cause soil disturbances that may reduce long-term site productivity. Site preparation and fertilization are often recommended as ameliorative practices for such disturbances, but few studies have actually quantified their effects on restoration. The purposes of this study were to quantify the effects of wet-weather harvest traffic in designated skid trails on soil properties and loblolly pine (Pinus taeda) growth, and to evaluate the ameliorative effects of site preparation. Study sites were established on wet pine flats of the lower Coastal Plain within the Francis Marion National Forest (Berkeley County, SC). Treatments were arranged in a split-split plot within a randomized complete block design. Treatments were two levels of traffic (nontrafficked, trafficked), four levels of mechanical site preparation (none, disking, bedding, disking + bedding), and two levels of fertilization (none, 337 kg /ha of 10-10-10 fertilizer). initially, the trafficking increased soil bulk densities and reduced soil water movement and subsequent growth of loblolly pine (years 1 and 2). Bedding combined with fertilization restored site productivity to non trafficked levels within 4 yr, but disking or fertilization treatments alone were not effective at ameliorating the traffic effects. The effectiveness of the bedding and fertilization treatments for amelioration of traffic effects was probably facilitated by the relatively small area of disturbed skid trails (<10%) found on these sites. Areas having more severe disturbance or higher percentages of disturbance might not be ameliorated as rapidly. South. J. Appl. For. 22(4):222-226.

scholarly journals Radioprotective Effect of Hesperidin: A Systematic Review

Medicina ◽  
2019 ◽  
Vol 55 (7) ◽  
pp. 370 ◽  
Author(s):  
Musa ◽  
Omyan ◽  
Esmaely ◽  
Shabeeb
Keyword(s):  
Clinical Trials ◽  
Survival Rates ◽  
Control Design ◽  
Case Control ◽  
Radioprotective Effect ◽  
Cellular Damage ◽  
Animal Cells ◽  
Meta Analyses ◽  
Late Side ◽  
Radioprotective Agent

Background and objectives: Ionizing radiation (IR) has been of immense benefit to man, especially for medical purposes (diagnostic imaging and radiotherapy). However, the risks of toxicity in healthy normal cells, leading to cellular damage as well as early and late side effects, have been major drawbacks. The aim of this study was to evaluate the radioprotective effect of hesperidin against IR-induced damage. Materials and Methods: The preferred reporting items for systematic reviews and meta-analyses (PRISMA) were applied in reporting this study. A search was conducted using the electronic databases PubMed, Scopus, Embase, Google Scholar, and www.ClinicalTrials.gov for information about completed or ongoing clinical trials. Results: From our search results, 24 studies involving rats, mice, and cultured human and animal cells were included. An experimental case—control design was used in all studies. The studies showed that the administration of hesperidin reduced oxidative stress and inflammation in all investigated tissues. Furthermore, it increased 30-day and 60-day survival rates and protected against DNA damage. The best radioprotection was obtained when hesperidin was administered before irradiation. Conclusions: The results of the included studies support the antioxidant, anti-inflammatory, and antiapoptotic abilities of hesperidin as a potential radioprotective agent against IR-induced damage. We recommend future clinical trials for more insights.

Seasonal activity and estivation of lumbricid earthworms in the midlands of Tasmania

Soil Research ◽  
1994 ◽  
Vol 32 (6) ◽  
pp. 1355 ◽  
Author(s):  
RB Garnsey
Keyword(s):  
Soil Moisture ◽  
Adult Development ◽  
Survival Rates ◽  
Soil Surface ◽  
Early Spring ◽  
Lumbricus Rubellus ◽  
Late Winter ◽  
Cocoon Production ◽  
Density And Biomass ◽  
Earthworm Activity

Earthworms have the ability to alleviate many soil degradational problems in Australia. An attempt to optimize this resource requires fundamental understanding of earthworm ecology. This study reports the seasonal changes in earthworm populations in the Midlands of Tasmania (<600 mm rainfall p.a.), and examines, for the first time in Australia, the behaviour and survival rates of aestivating earthworms. Earthworms were sampled from 14 permanent pastures in the Midlands from May 1992 to February 1994. Earthworm activity was significantly correlated with soil moisture; maximum earthworm activity in the surface soil was evident during the wetter months of winter and early spring, followed by aestivation in the surface and subsoils during the drier summer months. The two most abundant earthworm species found in the Midlands were Aporrectodea caliginosa (maximum of 174.8 m-2 or 55.06 g m-2) and A. trapezoides (86 m-2 or 52.03 g m-2), with low numbers of Octolasion cyaneum, Lumbricus rubellus and A. rosea. The phenology of A. caliginosa relating to rainfall contrasted with that of A. trapezoides in this study. A caliginosa was particularly dependent upon rainfall in the Midlands: population density, cocoon production and adult development of A. caliginosa were reduced as rainfall reduced from 600 to 425 mm p.a. In contrast, the density and biomass of A. trapezoides were unaffected by rainfall over the same range: cocoon production and adult development continued regardless of rainfall. The depth of earthworm aestivation during the summers of 1992-94 was similar in each year. Most individuals were in aestivation at a depth of 150-200 mm, regardless of species, soil moisture or texture. Smaller aestivating individuals were located nearer the soil surface, as was shown by an increase in mean mass of aestivating individuals with depth. There was a high mortality associated with summer aestivation of up to 60% for juvenile, and 63% for adult earthworms in 1993 in the Midlands. Cocoons did not survive during the summers of 1992 or 1994, but were recovered in 1993, possibly due to the influence of rainfall during late winter and early spring.

scholarly journals Four-year-performance of oak and pine seedlings following mechanical site preparation with lightweight excavators

Silva Fennica ◽  
2021 ◽  
Vol 55 (2) ◽  
Author(s):  
Noé Dumas ◽  
Mathieu Dassot ◽  
Jonathan Pitaud ◽  
Jérôme Piat ◽  
Lucie Arnaudet ◽  
...  
Keyword(s):  
Vegetation Cover ◽  
Untreated Control ◽  
Seedling Survival ◽  
Pinus Nigra ◽  
Quercus Petraea ◽  
Site Preparation ◽  
Pteridium Aquilinum ◽  
Preparation Methods ◽  
Basal Diameter ◽  
Mechanical Site Preparation

Mechanical site preparation methods that used tools mounted on lightweight excavators and that provided localised intensive preparation were tested in eight experimental sites across France where the vegetation was dominated either by (L.) Moench or (L.) Kuhn. Two lightweight tools (Deep Scarifier: DS; Deep Scarifier followed by Multifunction Subsoiler: DS+MS) were tested in pine ( L., var. (Loudon) Hyl. or Aiton) and oak ( (Matt.) Liebl. or  L.) plantations. Regional methods commonly used locally (herbicide, disk harrow, mouldboard plow) and experimental methods (repeated herbicide application; untreated control) were used as references in the experiments. Neighbouring vegetation cover, seedling survival, height and basal diameter were assessed over three to five years after plantation. For pines growing in , seedling diameter after four years was 37% and 98% greater in DS and DS+MS, respectively, than in the untreated control. For pines growing in , it was 62% and 107% greater in the same treatments. For oak, diameter was only 4% and 15% greater in , and 13% and 25% greater in , in the same treatments. For pines, the survival rate after four years was 26% and 32% higher in and 64% and 70% higher in , in the same treatments. For oak, it was 3% and 29% higher in and 37% and 31% higher in . Herbicide, when applied for three or four years after planting, provided the best growth performances for pines growing in and and for oaks growing in . For these species and site combinations, DS+MS and DS treatments reduced the neighbouring vegetation cover for one to four years following site preparation.Molinia caeruleaPteridium aquilinumPinus sylvestrisPinus nigracorsicanaPinus pinasterQuercus petraeaQuercus roburM. caeruleaP. aquilinumM. caeruleaP. aquilinumM. caeruleaP. aquilinumM. caeruleaP. aquilinumM. caerulea P. aquilinumP. aquilinum

scholarly journals Portal vein arterialization as a salvage procedure in hepatopancreatobiliary surgery: a systematic review

2021 ◽  
Vol 64 (2) ◽  
Author(s):  
Ali Majlesara ◽  
Omid Ghamarnejad ◽  
Elias Khajeh ◽  
Mohammad Golriz ◽  
Negin Gharabaghi ◽  
...  
Keyword(s):  
Systematic Review ◽  
Portal Hypertension ◽  
Portal Vein ◽  
Animal Studies ◽  
Survival Rates ◽  
Celiac Trunk ◽  
Salvage Procedure ◽  
Portal Vein Arterialization ◽  
Hepatopancreatobiliary Surgery ◽  
Meta Analyses

Background: Portal vein arterialization (PVA) is a possible option when hepatic artery reconstruction is impossible during liver resection. The aim of this study was to review the literature on the clinical application of PVA in hepatopancreatobiliary (HPB) surgery. Methods: We performed a systematic review according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We systematically searched the PubMed, Embase and Web of Science databases until December 2019. Experimental (animal) studies, review articles and letters were excluded. Results: Twenty studies involving 57 patients were included. Cholangiocarcinoma was the most common indication for surgery (40 patients [74%]). An end-to-side anastomosis between a celiac trunk branch and the portal vein was the main PVA technique (35 patients [59%]). Portal hypertension was the most common longterm complication (12 patients [21%] after a mean of 4.1 mo). The median followup period was 12 (range 1–87) months. The 1-, 3- and 5-year survival rates were 64%, 27% and 20%, respectively. Conclusion: Portal vein arterialization can be considered as a rescue option to improve the outcome in patients with acute liver de-arterialization when arterial reconstruction is not possible. To prevent portal hypertension and liver injuries due to thrombosis or overarterialization, vessel calibre adjustment and timely closure of the anastomosis should be considered. Further prospective experimental and clinical studies are needed to investigate the potential of this procedure in patients whose liver is suddenly de-arterialized during HPB procedures.

Reforestation of Orchard Stands and Savannahs on Pennsylvania's Allegheny Plateau

1985 ◽  
Vol 2 (1) ◽  
pp. 22-26 ◽  
Author(s):  
Stephen B. Horsley
Keyword(s):  
Site Preparation ◽  
Turn Of The Century ◽  
Herbaceous Plant ◽  
Black Cherry ◽  
Mechanical Site Preparation ◽  
White Ash ◽  
Survival And Growth ◽  
Terminal Shoot ◽  
Allegheny Plateau ◽  
Forest Openings

Abstract Orchard stands and savannahs are forest openings that failed to regenerate after turn-of-the-century logging and have been dominated by dense herbaceous plant growth for 50 or more years. The effectiveness of herbicide application, mechanical site preparation, and fertilization on survival and growth of five species of seedlings was tested over a 6-year period. Neither site preparation nor fertilization significantly increased survival of any species above the control during the first 2 years after planting. Residues of picloram, one of the herbicides used during site preparation, reduced survival of all species, except white ash, below that of the control. Fertilization reduced survival of all species. Black cherry was the only species that grew better as a result of the treatments. Weed removal significantly increased black cherry seedling growth, but much of this increased growth was in branches, rather than the terminal shoot. Mechanical site preparation plus herbicide did not increase growth of black cherry seedlings above that of herbicide alone during the first 2 years and had the disadvantage of stimulating reinvasion by grass. Deer which penetrated the protective fence interfered with evaluation of growth after the second year. North J. Appl. For. 2:22-26, Mar. 1985.

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