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 ◽  
...  

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.

2000 ◽  
Vol 76 (2) ◽  
pp. 349-353 ◽  
Author(s):  
J. M. Kranabetter ◽  
D. Yole

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


2019 ◽  
Vol 49 (10) ◽  
pp. 1311-1319
Author(s):  
Karin Hjelm ◽  
Urban Nilsson ◽  
Ulf Johansson ◽  
Per Nordin

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.


Silva Fennica ◽  
2021 ◽  
Vol 55 (2) ◽  
Author(s):  
Noé Dumas ◽  
Mathieu Dassot ◽  
Jonathan Pitaud ◽  
Jérôme Piat ◽  
Lucie Arnaudet ◽  
...  

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


Forests ◽  
2018 ◽  
Vol 9 (11) ◽  
pp. 717 ◽  
Author(s):  
Marta Aleksandrowicz-Trzcińska ◽  
Stanisław Drozdowski ◽  
Marcin Studnicki ◽  
Henryk Żybura

While some tree species can regenerate naturally without mechanical site preparation (MSP), Scots pine has been shown to benefit from this process. We compared three methods: using a double-mouldboard forest plough (FP), an active single-disc plough (AP), and a forest mill (FM), as well as a no-MSP control, in terms of growth, survival and density of occurrence of pines during the first 4 years of natural regeneration. Moisture conditions were expressed via calculated de Martonne aridity indices, while the microhabitats generated via different MSP methods were further characterised by the total contents of N and C, and the C/N ratio, P2O5, and base cations, as well as bulk density and actual moisture. The trials showed inferior regeneration without MSP in terms of the density and cover of young pines. Any of the studied treatments influenced survival, though the best growth was achieved by seedlings using the FP and AP methods, while the best density and evenness results were obtained using AP. The factors most influencing regeneration features were high precipitation during the first growing season after sowing and reduced competition with other vegetation in the cleared area. This impact seems far more important than the capacity of different MSPs to produce differentiation in soil microhabitats in terms of nutrient status or bulk density.


2001 ◽  
Vol 79 (12) ◽  
pp. 1449-1464 ◽  
Author(s):  
Darwyn S Coxson ◽  
Janet Marsh

Lichen community development was examined in a postfire chronosequence from lodgepole pine (Pinus contorta Dougl. ex Loud var. latifolia Engelm.) forests in the Omineca region of north-central British Columbia and in stands originating from logging in the early 1980s. Fire-origin stands showed dense regeneration of pine and widespread growth of acrocarpous mosses such as Polytrichum spp. As canopy thinning progressed, Cladonia spp. lichens initiated development at the forest floor surface. By 50–100 years after stand origin, Cladina mitis and Cladina rangiferina dominated at the forest floor surface, remaining at high cover values well into the second century of stand development. Late seral stages of stand development (approximately 150+ years) showed increasing basal area and canopy cover of lodgepole pine, with feathermoss mats (e.g., Pleurozium schreberi) replacing terrestrial lichens at the forest floor surface. Stand ordinations confirmed these groupings of species. Stand structural factors that correlate best with lichen mat development include tree density, basal area, and canopy cover. Changes in the leaf area index and associated litterfall loading appear to precipitate the replacement of terrestrial lichen mats in "old-growth" stands. Interestingly, this trend was reversed in mature stands where winter harvesting of trees removed canopy cover without disturbing the forest floor surface. Lichen cover in these sites, 15 years after harvest, exceeded that of comparably aged fire-origin stands. Summer harvesting (with a presumed greater disturbance of soils) did not trigger a similar rebound of lichen communities. Instead, vascular plants appeared to invade these sites, following a seral sequence different from that occurring in fire-origin stands.Key words: terrestrial lichens, pine woodlands, caribou habitat.


2005 ◽  
Vol 35 (8) ◽  
pp. 1854-1866 ◽  
Author(s):  
M D MacKenzie ◽  
M G Schmidt ◽  
L Bedford

Mechanical site preparation (MSP) changes the distribution and character of forest floor and mineral soil and may affect soil nutrient availability, soil water content, and soil temperature. The effects of different kinds of MSP were compared to a control in the tenth growing season at two research sites in northern British Columbia. To compare MSP results with those of the natural disturbance regime, a burned windrow treatment was also included in the analysis. The bedding plow, fire, and madge treatments all had significantly greater crop-tree growth compared to the control. The bedding plow and madge treatments had significantly lower soil bulk density, higher soil temperature, and lower soil water throughout the growing season compared with that of the control. The bedding plow also resulted in significantly higher concentrations of total carbon, total nitrogen, NH4+, and NO3–than that of the control, at both the 0–10 and 10–20 cm depths. The madge rotoclear resulted in significantly greater potential mineralizable N than that of the control. Ionic resins bags, installed for one growing season, did not show any significant treatment differences in available soil nitrogen. MSP did not reduce soil fertility on these sites when compared with an untreated control, but it is difficult to say that it improved it.


2001 ◽  
Vol 18 (1) ◽  
pp. 7-13 ◽  
Author(s):  
Andrew J. Londo ◽  
Glenn D. Mroz

Abstract This article summarizes the information in the literature concerning site preparation in wetlands with special emphasis on bucket mounding. Mounding as a site preparation technique has been used since the 18th century for reestablishing tree species on wet sites, and it is commonly used in parts of Canada and Scandinavia. In the Lake States, a version of mounding called bucket mounding is coming into use for regenerating cutover wetland sites. Bucket mounding differs from other mounding operations in that it is used exclusively in wetlands and uses a tracked excavator to create the mounds, rather than equipment towed behind or attached to a skidder or bulldozer. In wet areas, bucket mounding creates a raised planting site, resulting in more aerated soil above the water table, warmer soil temperatures during the growing season, greater nutrient availability, and a small degree of vegetation control. Bucket mounding mimics the natural pit and mound microtopography that naturally occurs as a result of wind storms across the Great Lakes Region. This microtopography is important for natural regeneration establishment and growth. This article provides an overview of natural pit and mound formation, types of mounds, mounding equipment, the effects of mounding on the seedling environment, and planted species survival. Additional considerations for Lake States conditions are also discussed. North. J. Appl. For. 18(1):7–13.


2015 ◽  
Vol 45 (4) ◽  
pp. 411-421 ◽  
Author(s):  
Richard W. Reich ◽  
Jean L. Heineman ◽  
Amanda F. Linnell Nemec ◽  
Lorne Bedford ◽  
Jacob O. Boateng ◽  
...  

Site preparation can improve lodgepole pine (Pinus contorta var. latifolia Engelm. ex S. Watson) survival and growth; however, we lack information regarding possible interactions between treatment effects and the impacts of western gall rust (Endocronartium harknessii (J.P. Moore) Y. Hirats.) and comandra blister rust (Cronartium comandrae Peck). Mechanical and burning techniques examined over 24 years at a sub-boreal British Columbia site did not significantly increase rust infection rates or characteristics relative to an untreated control. Most infection occurred before age 10 years and at heights <2 m. By age 24 years, 22% and 10% of pine had sustained at least one western gall rust or comandra blister rust stem infection, respectively, but only 4% of western gall rust infected trees were dead, compared with 60% of comandra blister rust infected trees. Exploratory regression analysis of the relationship between tree volume and percent stem encirclement and infection height suggested that volume of 24-year-old pine infected with western gall rust averaged 8% less than the corresponding volume of uninfected trees. Over 24 years, estimated stand-level, rust-related volume loss was 8.4%, with the majority due to mortality from comandra blister rust. One-fifth of estimated volume loss was provisionally attributed to growth reductions among live western gall rust infected pine.


2017 ◽  
Vol 47 (8) ◽  
pp. 1140-1144 ◽  
Author(s):  
Cindy E. Prescott ◽  
Anya Reid ◽  
Shu Yao Wu ◽  
Marie-Charlotte Nilsson

Mechanical site preparation is assumed to reduce soil C stocks by increasing the rate at which the displaced organic material decomposes, but the evidence is equivocal. We measured rates of C loss of forest-floor material in mesh bags either placed on the surface or buried in the mineral soil at four sites in different regional climates in British Columbia. During the 3-year incubation, buried forest-floor material lost between 5% and 15% more C mass than material on the surface, with the greatest difference occurring at the site with the lowest annual precipitation. Studies of the long-term fate of buried and surface humus are needed to understand the net effects of site preparation on soil C stocks.


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