1. Mechanical Treatments Why use mechanical treatments? What factors effect use of mechanical treatments? What types of mechanical treatments are there? How effective are mechanical treatments?

2. Mechanical Treatments Why Use Mechanical Treatments? –Alter dense, closed canopies Woody plants (trees & shrubs*) Succulents Herbaceous plants Credit: laspilitas.com

3. Mechanical Treatments Why Use Mechanical Treatments? –Alter woody plants* Overstory & understory/shrub –Competes for »Sunlight »Water »Nutrients –Limit productivity of herbaceous –Unsuitable for many wildlife species »Edge »Early successional Credit: ecotours.com

4. Mechanical Treatments Why Use Mechanical Treatments? –Enhance herbaceous plant growth Set back succession Disrupt compacted soils Remove debris Manipulate soil micro-topography

5. Mechanical Treatments Why Use Mechanical Treatments? –Alter soil & litter conditions –Site & seed-bed preparation NOT a substitute for prescribed fire - Combination often best

6. Mechanical Treatments Factors to Consider –Wildlife factors Obligate wildlife species –Interior species Ecological requirements of species –Edge species & species with multiple habitat needs Native plants: pros & cons Forage (open area) to cover ratios Proximity of treated sites to other habitats Influence on vertical structure Control of spot grazing (livestock attraction)

7. Mechanical Treatments Factors to Consider –Watershed/soil factors Soil fertility Soil depth Debris & litter Erosion Aspect Slope Topography Season of treatment

8. Mechanical Treatments Factors to Consider –Vegetative factors Reseeding & plant propagation Invasion by “weeds” & exotics Target plants: pros & cons Sprouting potential (return interval) Maintenance of openings Impact on plant diversity Season of treatment Credit: californaichaparral.com

9. Mechanical Treatments Overstory Removal –Areas cleared of trees & tree manipulations Harvest (silviculture) Timber Stand Improvement

10. Mechanical Treatments Overstory/Tree Removal –Harvest Chainsaw Harvester (mechanical shears or saw)

11. Mechanical Treatments Timber Stand Improvements (TSI; Tending/Intermediate Treatments) –Thinning –Pruning –Vertical & horizontal structure

12. Mechanical Treatments Understory and Shrub Removal –Areas cleared of woody species Mosaic patches Cleared strips Large areas

13. Mechanical Treatments Level of Understory/Shrub Removal (Payne and Bryant 1994)

14. Mechanical Treatments Thinning –Individual tree or shrub treatment Chainsaw or handsaw Heavy equipment Grubbing –Below ground severing Clipping –Above ground severing Vegetation/land sculpting

15. Mechanical Treatments Thinning –Mechanical grubbing U-shaped blade mounted on a tractor –Depending on tree/shrub type and terrain »Crawler (rough terrain; poor movements; high soil disturbance) »Wheel loader »Farm tractor

16. Mechanical Treatments Thinning –Mechanical grubbing CrawlerWheel-loader Farm tractor Credit: reveg-catalog.tamu.edu

17. Mechanical Treatments Thinning –Mechanical grubbing Excavator –Considerable site disturbance –Wide swath –200-500 trees/hr Credit: reveg-catalog.tamu.edu

18. Mechanical Treatments Thinning –Mechanical clipping Hydraulic shears –Spray stump for sprouters (e.g., mesquite, redberry juniper) Credit: libertyhilltractor.comCredit: onlineattachements.com

19. Mechanical Treatments Clearing –Areas cleared of all woody species Remove aboveground growth Sever roots Uproot plants from soil Usually a combination of methods

20. Mechanical Treatments Clearing –Chaining (or cabling, railing, etc.) Ship anchor chain Pulled between two tractors 61-122 m (200-400 ft) in length 59-111 kg/m (40-75 lbs/ft) U-shape

21. Mechanical Treatments Clearing –Chaining Credit: fs.fed.us

22. Mechanical Treatments Clearing –Chaining Uproots plants & severs Used for tree felling –Dense to moderate stands –High soil moisture best –Not limber plants Double-chaining (both directions) & Elevated chaining Effects short-lived & used with other methods –Herbicide before and/or burn after Common in West –Pinyon pine, juniper, mesquite Credit: reveg-catalog.tamu.edu

23. Mechanical Treatments Clearing –Rootplow V-shaped, horizontal blade 3-5 m (10-16 ft) wide Large crawler tractor Depth 31-36 cm (12-14 in)

24. Mechanical Treatments Clearing –Rootplow Severs roots & crowns –Best for trees <4” dia. Prevents regrowth –Often followed by chaining or raking Severe soil disturbance –May need to reseed Long-term results –85-99% tree mortality –10-20 yrs before shrubs return Credit: reveg-catalog.tamu.edu

25. Mechanical Treatments Clearing –Web plow V-shaped, horizontal blade Large grader Depth 10-15 cm (4-6 in)

26. Mechanical Treatments Clearing –Web plow Severs roots & crowns Prevents regrowth Worked well on saw palmetto

27. Mechanical Treatments Clearing –Disking Blades 61-91 cm (24-36 in) Units 2.5-3.7 m (8-12 ft) width Crawler or tractor Credit: reveg-catalog.tamu.edu

28. Mechanical Treatments Clearing –Disking Severs roots & crowns shallow species –Not “heavy” shrubs/brush and trees Problem severing deep rooted species Disturbs soil –Stimulates early successional growth Effects on shrubs short-lived May increase deep-rooted species May benefit wiregrass

29. Mechanical Treatments Clearing –Roller-chopping Cylindrical metal drum –Adjustable weight Blades parallel to axis Crawler or tractor Credit: reveg-catalog.tamu.edu

30. Mechanical Treatments Clearing –Roller-chopping Severs stems Crushes plants One or more drums Water or cement filled Disturb soil Increase herbaceous plants Required every 2-5 years with strong resprouters Often used in conjunction with fire Credit: forestryimages.org

31. Mechanical Treatments Clearing –Renovators/Aerators (roller chopper) Small blades Staggered, cylindrical pattern Double drums 46-107 cm (18-42 in) diameter Filled with water Credit: reveg-catalog.tamu.edu

32. Mechanical Treatments Clearing –Renovators/Aerators Moderate to dense shrubs –Can remove top growth to stimulate regrowth Small blades –Chop debris –Form basins in soil Credit: noble.org

33. Mechanical Treatments Clearing –Shredder Brush –Rotating horizontal blade, vertical shaft Flail –Rotating vertical blade, horizontal shaft 2-6 m (7-20 ft) wide

34. Mechanical Treatments Clearing –Shredder (brush hog & rotobeater) Cut woody plants and debris (<12”) Manicured appearance and level height Prone to mechanical failures Effective on sm. trees and non-sprouters Often in conjunction with fire Credit: reveg-catalog.tamu.edu

35. Mechanical Treatments Clearing –Mower Flail Rotary Sickle-bar Tractor Remove top-growth Herbaceous and very light woody plants Very temporary effects Often used in conjunction with fire Credit: allswisstractors.com Credit: tractorbynet.com

36. Mechanical Treatments Clearing –Blading or dozing –Often used with other methods –Much disturbance

37. Mechanical Treatments Re-sprouting (lots of browse!) –Disking –Roller-chopping –Shredding –Mowing Roots Crowns Stems Credit: images.google.com

38. Mechanical Treatments Other –Raking –Bailing

39. Mechanical Treatments Planting and tending –Seeders Drills & spreaders –Planters –Disturbance USDA photo by: Tim McCabe

40. Mechanical Treatments Planting and tending –Cultipackers & rollers –Hoes, disks, plows, etc. –Disturbance –Soil compaction

41. Mechanical Treatments Other Plant Harvesting

42. Mechanical Treatments –Why they are used –Types –Factors affecting their use and effectiveness