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Vegetation Management Alternatives Section II. What are the alternatives and what is their silvicultural effectiveness? Al Wiensczyk, FORREX...

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Presentation on theme: "Vegetation Management Alternatives Section II. What are the alternatives and what is their silvicultural effectiveness? Al Wiensczyk, FORREX..."— Presentation transcript:

1 Vegetation Management Alternatives Section II. What are the alternatives and what is their silvicultural effectiveness? Al Wiensczyk, FORREX...

2 What are the Alternatives? Methodology Reviewed the scientific literature for information Used experiential knowledge of project team and others Gathered info on species autecology and treatment effectiveness Very limited info on some treatments, quite extensive on others Similarly very limited data on some competitive species – lots on others

3 Canadian Forest Management Database Dean Thompson What are the Alternatives? CCFM Database

4 What are the alternatives? Non-crop vegetation in the boreal forest Positive or negative effects on crop trees Depends on  Autecology of respective species (including reproductive strategy).  Non-crop species density  Non-crop species size relative to that of the crop trees  Differences in site quality Effect may change over time

5 What are the alternatives? Autecology information Life Form/species Reproductive strategy Uses and BenefitsEffects on conifers Trees Trembling aspen Populus tremuloides Suckers Basal sprouts (rare) Seed: wind (rare) Crop tree Nutrient rich litter aids in nutrient cycling and increases soil fertility. May reduce weevil damage Provides browse, cover and nesting habitat for ungulates, small mammals and birds. Provides food for beaver Buds are eaten by ruffed grouse Reduces light availability Competes for growing space Competes for rooting space May cause whipping damage Shrubs Sitka/green alder Alnus viridis/ Alnus crispa Seed: wind/water Basal sprouts Nitrogen fixation improves site fertility Builds up site organic matter Stabilizes slopes and controls erosion Suppresses grass and raspberry competition Reduces light availability Reduces moisture availability Reduces nutrient availability May cause snow press

6 What are the alternatives? Autecology Information Life Form /Species Response to Disturbance Overstory removal FireCuttingMechanical Site Preparation Low intensity Medium to high intensity Trembling aspen Populus tremuloides Root suckering, some stump sprouting Winter logging 4x more suckers Regen from seed on exposed mineral soil Vigorous sprouting when organic layer disturbed but not removed and root systems not damaged Adapted to environment with recurring fires; Regenerates from suckers Spring fires – increased regeneration  Sprout from stump or suckers; Cutting in June – lower number of suckers Sucker production proportional to degree of cutting; Girdling during growing season effective Surface treatment will increase sucker production Seeding on mineral soil (minimal) High cultivation treatments may control aspen Sitka/green alder Alnus viridis - Alnus crispa Increase in stem numbers Stimulated more by winter than summer logging. Often favoured by burning; Killing cambium at ground level will kill plant. If only stem killed will resprout from stumps.  Control  Increase in stem numbers through stump sprouts; July and August – least sprouting and height growth Treatments that remove roots – greater success Seeds in to disturbed sites

7 Vegetation Management Treatment Options Decision Making Process ( from Wagner et al. 2001) What are the alternatives? Silvicultural activities (harvesting, site preparation, thinning ) Autecological characteristics of unwanted forest plants Desired stand Yes No Prevention loop Removal loop Release treatments Favourable environment No Alter silvicultural activities

8 What are the alternatives? Treatment Groups Harvesting Systems Physical Thermal Cultural Chemical and Biological spray

9 What are the alternatives? Silviculture and harvest systems Silviculture System  Clearcut, modified clearcut, shelterwood, selection Harvest disturbance  Influenced by Harvest system Season of harvest Equipment used Operator training and skill Harvest System  Full tree, tree length, cut-to-length

10 Mechanical Site preparation Brushing  Manual  Motor-manual  Mechanical Girdling Mulches What are the alternatives? Physical Treatments

11 What are the alternatives? Thermal Treatments Prescribed Fire Steam

12 Vegetative ReproductionSexual Reproduction Shoot Origin Sprouts Root Origin Sprouts Windborne Seed Seed Bank e.g., maple, alder, birch, dogwood, hazel, willow, Labrador tea Roots in organic layer Roots in mineral soil e.g., grasses, birch, fireweed, poplar, willow e.g., dogwood, cherry, rose, raspberry, blueberry Silvicultural treatment Microsite Category e.g., grasses, blueberry e.g., poplar, rose, raspberry None Undisturbed Harvest Overstory removed; ground undisturbed  0 to   Mechanical site preparation Upland mineral soil Organic partially displaced L and part of F (e.g. shallow screef)  LFH removed and mineral soil either: Depressed (deep screef)   to   Level (screef)  to    Raised (mineral soil mound)   to   LFH inverted with mineral soil cap (mineral mound on organic layer)  to  to   LFH and mineral soil mixed (tilling)  to   Lowland Organic soil Part of Of removed (e.g., by shearblading)   to  N/A  Drainage of layer (e.g., by ditching)  N/A0  Prescribed fire Light   Moderate   Severe   Cutting Active< 25 cm  -- > 25 cm  -- Dormant< 25 cm  -- > 25 cm  -- Microsite description Effect of disturbance on reproduction  = promotes (  = strongly promotes) 0 = no effect  = discourages (  = strongly discourages)

13 What are the alternatives? Cultural Treatments Seedling Culture Cover Crops Grazing

14 What are the alternatives? Chemical and Biological Spray Treatments Herbicides  Application methods Biologicals

15 Vegetation Management Alternatives Section III: What are the environmental consequences of using silviculturally effective alternatives? Kathie Swift, FORREX Wayne Bell, OMNR

16 What are the environmental consequences? Environmental effects Lots of literature available on the effects of some treatments, less for others Due to complexity of responses, focus put on principal messages Treatments can have a positive effect on one element and a negative effect on another

17 Air Quality Soil Properties/Nutrition Water Quality and Quantity Photo: Utah Bureau of Land Management Photo: Rhodes University What are the environmental consequences? Abiotic Values

18 Plants (diversity) Fish/Fish Habitat Terrestrial Invertebrates Amphibians and Reptiles Song birds Small Mammals Mid-large Mammals What are the environmental consequences? Biotic Values

19 Stand/Landscape changes What are the environmental consequences? Spatial Values

20 Environmental Value Harvesting SystemPhysical Treatments Thermal TreatmentCultural Treatments Chemical and Biological Spray Treatments Water Quality/ Quantity All harvest systems  Sedimentation issues  Road construction machine use around streams and stream crossings.  Steep slopes  Can change soil properties →  surface water flow →  risk of erosion (Wells and Jorgensen 1979).  Windthrow post harvest →  sedimentation during seasonal runoff MSP  Can  ground water table.  Can change soil properties →  overland flow →  soil erosion and nutrient loss → water quality and the aquatic environment (Chang 2006).  Steep slopes can exacerbate the issue. Prescribed Fire  Addition of biocarbonates, nitrates, ammonium, and organic nitrogen from ash  Not usually concentrated enough to pose a health risk to humans or animals (Chandler et al. 1983, Richter et al. 1982)  However some issues identified in northern Quebec and Alberta studies Grazing by ungulates  Poor livestock management practices  allowing grazing ungulates to concentrate in streams and riparian zones →  water contaminants →  water temperatures (Foster 1998). Ground and aerial application  Potential contamination of streams principle concern  May enter forest streams by  direct application,  leaching through soil profile,  mass overland flow  Rapid dilution with downstream movement reduces concentration.  No hazard when care taken to protect streamside vegetation, and stream from direct contamination (Pritchett 1979) What are the environmental consequences? Example of how information is presented

21 What are the environmental consequences? Example of how information presented Silviculture practice BioticBiotic/AbioticAbiotic Canopy# Tree speciesTree diameter SnagsDowned woody material Organic matter (LFH) Mineral soilRutting or Compaction Physical Logging ↓↓ ↓↑↓↓↓↑↓↑↑↑ Thinning ↓↓↑↓↓↓↑↑ Mechanical SIP ↓↓↑↑↓↓↓↑ Brushing & girdling ↓↓↑↑↑↓00 Mulching --↑--↓↓↑ Thermal Prescribed burning ↓↓↓↓ ↑↑0 Cultural Seedling ↓↓0 ↑↓↑00↑↓↓0 Cover cropping ↓0↑00↑↓↓0 Animal grazing ↓↓↑0↓↓↑↓ Chemical & Biological Chemical ↓↓↑00000 Biological ↓↓↑00000 Fertilization ↑0↑00↓00


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