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VARIABLE RETENTION HARVESTING ON POTLATCH FORESTS

VARIABLE RETENTION HARVESTING ON POTLATCH FORESTS. RETENTION SYSTEM?. Retains structure , such as live and dead trees and woody debris, for at least one rotation Provides structural diversity and forest or residual tree influence over the majority of a cutblock

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VARIABLE RETENTION HARVESTING ON POTLATCH FORESTS

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  1. VARIABLE RETENTION HARVESTING ON POTLATCH FORESTS

  2. RETENTION SYSTEM? • Retains structure, such as live and dead trees and woody debris, for at least one rotation • Provides structural diversity and forest or residual tree influence over the majority of a cutblock • “Influence” generally extends at least one tree length from an edge • Usually are always planted • You can also adapt traditional systems to the VR approach • BOTTOM LINE- Its an approach that modifies traditional forestry to better address the non silvicultural issues-such as bio-diversity and visuals. Adaptedfrom the March 1999, BC Operational Planning Regulations

  3. DESIGN USING “ANCHORS POINTS” • Representative range of tree sizes, species, multiple canopy layers, conifers & deciduous • Understory vegetation and forest floor • Snags, decay features,coarse woody debris • Riparian, rock outcrops • Nests, bear dens, vets • Gullies, seeps, unique floraor terrain features • Unsafe areas • Difficult logging • Poor planting sites • Visual screens • Veteran trees

  4. RETENTION HARVEST MYTHS • IT PROMOTES GRAND FIR • YOU CANT BURN • IT’S TO EXPENSIVE • IT’S TO COMPLICATED • IT’S JUST HIGH GRADING • IT’S JUST A CLEARCUT • IT’S A GROUP SELECTION • IT’S JUST UN-EVEN AGE MGT

  5. JUST NEW WAYS OF THINKING • FOREST INFLUENCE • ANCHOR POINTS • SPACING?? • TARGETING BIOLOGICAL LEGACIES IN PATCHS NOT SINGLE TREES • PATCHES ARE KEY

  6. OUR LANDSCAPESTRATEGY • Retention, shifting mosaic, and green-up/adjacency. • Each plays a role in providing structure for organisms and ecological processes at different scales. • Our retention strategy seeks to maintain the diversity of plants, animals, and ecological processes at a stand level by retaining biological legacies over the long-term. • Our green-up/adjacency strategy targets the ecological balance of forest structure at a slightly larger scale by limiting the amount of early-successional vegetation within a particular drainage. • Our shifting mosaic strategy seeks to maintain biodiversity at a much coarser scale, such as the Landscape Management Unit, by ensuring the maintenance of a diversity of forest structure types.

  7. GREEN TREE RETENTION • USED WITH TRADITIONAL TREATMENTS • INCLUDES RANDOMLY PLACE ANCHOR POINT RETENTION • GENERALLY POTLATCH IS MOVING TOWARD RETAINING MORE PATCH RETENTION VS. DISPERSED • LESS IMPACT ON GROWTH WITH PATCH RETENTION

  8. The Potlatch GTR Program consists of a number of facets, including: • Riparian stands • Upland stands • Old growth reserves • Special Sites • Retention in harvest units • Uneven-aged management stands • Visual Management Corridors

  9. THE POTLATCH DEFINITION • The retention harvest system (RHS)is designed to meet visual constraints while removing more volume than shelterwood harvests in units with viewshed restrictions. The goal is to maintain enough tree canopy to have forest or residual tree influence over the majority of the harvest unit and leaves some long-term live and dead reserve trees or groups of trees for at least one rotation. The retention harvest will leave approximately 20% of the stand volume (depending on stand location and shape) and will be representative of the average preharvest stand. Openings are generally less than four tree lengths wide but may be any length. Residual trees may be in a patch/group or strip/stringer pattern and will be strategically placed in the unit to minimize the visual impact of the logging. Harvested areas are generally reforested through planting. Once the regeneration has reached acceptable heights as described in the Potlatch green-up requirements, a portion of the residual stand may be removed.

  10. POTLATCH RETENTION EXAMPLE 2000 SCATTERED VETEREN PINES RIPARIAN RETENTION ADVANCED REGEN AREAS PLANTED

  11. POTLATCH EXAMPLE 1990

  12. POTLATCH EXAMPLE 1999

  13. MARATHON AERIAL VIEW

  14. . MARATHON TRIAL

  15. MARATHON RETENTION

  16. ESTIMATING TREE INFLUENCE

  17. LOGGING AND HAZARD MANAGEMENT PLAN

  18. ACRES AND VOLUME • Unit Acres: 95 • Net All harvested: 1,422 MBF • Net All Residual Volume: 345 MBF

  19. RETENTION AREAS • Total Retention in-groups: 13.6 Ac • Total number of Groups: 7 • Smallest Group: .1 Ac • Largest Group: 6 Ac (Linked class II riparian areas)

  20. WHY WOULD YOU VR? • WHEN VISUALS OR OTHER NONE-SILVICULTURAL ISSUES REQUIRE YOU TO DO SOMETHING DIFFERENT • IN THESE SITUATIONS VR USUALLY HAS A HIGHER NPV THAN A TRADITIONAL SYSTEM • IT CAN ALLOW YOU TO CUT MORE VOLUME GIVEN CLEARCUT SIZE OR ADJACENCY CONSTRAINTS

  21. LAYOUT STEPS • FIGURE OUT HOW IT WILL BE LOGGED • LOCATE AND MARK CRITCAL SCREENS AND ANCHOR POINTS LIKE STREAMS-MEASURE AND MAP THEM- CALCULATE THE FOREST INFLUENCE • DETERMINE WHAT YOUR AVERAGE PATCH SIZE WILL BE AND HOW MANY PATCHES YOU WILL NEED TO MEET THE 50% RULE MAP THOSE OUT • LAY-OUT THE REMAINING PATCHS ON THE GROUND • INVARIABLY IT WILL DIFFER FROM YOUR PAPER PLAN • UPDATE YOUR MAP • YOUR DONE

  22. TIPS • YOU WANT LARGE OPENINGS • THE TENDENCY IS TO LEAVE TO MANY TREES • SCATTERED TREES ALL OVER GET IN THE WAY • CONCENTRATE YOUR RETENTION IN PLACES YOU DON’T WANT TO BE IN OR IN PLACES YOU DON’T WANT TO BE SEEN • MAKE SURE YOU CAN SITE PREP AND PLANT THE POST HARVEST STAND • ALWAYS BE AWARE OF HOW MUCH VOLUME YOUR LEAVING AND HOW EASY IT WLL BE TO GO BACK TO IT.

  23. BURNING • BEST IF A SPRING BURN • LINE UNIT AS NORMAL • THE BIGGER THE PATCH THE EASIER IT IS TO SAVE • KEEP SLASH OUT • DON’T TRY AND FALL TREES OUT OF A PATCH • IT MAY BE OK IF A FEW BURN UP

  24. HAZARD MANAGEMENT

  25. BLOWDOWN • LOOK AT SOILS AND STAND HISTORY • PREVAILING WINDS • RETENTION AREAS TUCKED OUT OF THE WAY OF THE PREVAILING WINDS? • SPECIES MIX? • PATCH SIZE AND SHAPE

  26. OBSERVATIONS • IF PLANNED RIGHT VR UNITS APPEAR MORE NATURAL THAN ST, SW OR CT • WHEN COMPARED TO TRADITIONAL PARTIAL CUTS YOU HAVE MORE CONTROL OVER HAZARD MANAGEMENT, SITE PREP, AND REGENERATION • THE UNITS ARE EASIER TO RELOG AND DO LESS DAMAGE TO REGEN • EVEN IN CASES WHERE YOU CUT MORE WITH VR THERE IS MORE HIDING COVER AND THE STAND ACTUALLY APPEARS LARGER THAN IF YOU A TRADITIONAL APPROACH • LOGGING COSTS CAN ACTUALLY BE LOWER AND THE UNITS CAN ACTUALLY BE SAFER THAN OTHER PARTIAL CUTS

  27. QUESTIONS

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