Snowshoe Hare browsing damage on seedling trees underplanted in Dothistroma and MPB attacked stands Snowshoe Hare habitat Frank Doyle Wildlife Dynamics Consulting Box 129 Telkwa, B.C. V0J 2X0 CA NA DA Email: doyle@bulkley.net http:/ / www.bulkley.net/ ~ doyle/ Snowshoe Hare impacts on seedlings Strategies to reduce the damage on seedlings Ecosystem Change and Hare Population Dynamics
Snowshoe Hare Habitat Hares Require 2 key habitat attributes 1. Cover 2. Food MPB and Dothistroma are creating hare habitat Hare browsed stand P.G. Dothistroma attacked stand Kispiox MPB killed stand Ootsa Lake
Dothistroma M.P.B
Restoration Challenge - Unlike traditional forestry, young MPB and Dothistroma attacked stands have little or no commercial value. - In addition other young commercial tree species may be present in the block. - ~ 40,000 ha of Dothistroma attacked Pine in the Skeena-Stikine and Kalum Forest Districts - Ideally therefore as the trees die and the light levels increase underplanting is seen as the preferred option.
Snowshoe Hare impacts on seedlings Underplanted seedling browsing damage observed 1 month post planting (Dunkley, Prince George): Dow & Danskin 2007 100 90 80 70 60 Douglas Fir Pine Spruce (%) 50 40 30 20 10 0 % Seedlings Damaged Hares Ungulates Voles Damage and species responsible
Ecosystem Impacts of Hare Browsing Kluane, Yukon
Strategies to reduce the damage on seedlings Cover removal Trials - Established in 2006 to determine if the removal of the dead/dying 25-40 year old Dothistroma pine trees would reduce browsing damage Tree Shelter and Alternative Planting Strategy Trials (Established in 2007) (A) Tree shelters to protect seedlings Without the removal of cover can tree shelters be used to protect seedlings (Practical and cost effective?). (B) Planting strategies (Species, density and stock types) Without shelters are there any other ways to attain desirable stocking density?
Removing Cover to protect Seedlings Palatability of different tree species Kispiox 2006 Spruce for breakfast
Seedling Browsing Damage in Dothistroma Trial Cleared Areas 1 Year after Planting : 4 trial sites, covering the typical range of site conditions in the Kispiox Forest District. : Spruce, Hemlock and sub-alpine Fir (Cedar excluded) Control 1 ha Units Cleared 1 ha Units Seedling trees monitored around each transect Hare pellet transects
Percentage Browse in control and adjacent cleared areas with each Trial Unit 90 80 70 Control Cleared 60 50 40 30 20 10 0 Unit A Unit B Unit D Suskwa No Cattle Trial Units Free Range Cattle
Relationship between browsing and the number of hare pellets 40 35 30 Seedlings Browsed (%) 25 20 15 10 5 Regression 95% confid. 0-5 -0.2 0.2 0.6 1.0 1.4 1.8 2.2 Hare Pellets per Quadrant
Relationship between browsing and herb/shrub coverage in cleared Areas 40 Seedlings Browsed (%) 35 30 25 20 15 10 Potential Threshold in Cover? 5 0 Regression 95% confid. -5 0 10 20 30 40 50 60 70 Herb-Shrub Cover (> 0.5m high)
Percentage of Seedlings with Browse Damage 100 90 80 70 Hemlock sub-alpine fir Spruce 60 50 40 30 20 10 0 Units A, B & D Cleared No Cattle Units A, B & D Control Site Type Suskwa Cleared Suskwa Control Free Range Cattle
Percentage of Seedlings with >50% of overall browse damage 80 70 60 Hemlock sub-alpine fir Spruce 50 40 30 20 10 0 Units A, B & D Cleared No Cattle Units A, B & D Control Site Units Suskwa Cleared Suskwa Control Free Range Cattle
Tree Shelter and Alternative Planting Strategy Trial - Seedling protection, seedling density, seedling type Brown Bear October 2007
Trial Outline 12 sites planted summer 2007 Tree Species planted: Cedar, Hemlock, subalpine fir, Spruce Range of site types: low-high herb/shrub coverage Range of planting strategies - Different tree shelter types (height, cost, portability, durability) -Planting Density -Seedling size -Naturals versus Control (Nursery) seedlings Elenore Lake October 2007 Paul Hanna: Silverwood Consulting Ltd., MoFR, Gitxsan and Wet'suwet'en First Nations, Wildlife Dynamics.
Trial Layout = 90 sample pods (High density planting 3000-3600 per ha) 75 cm Trial Block Layout Jumbo Spruce
Sx Trial Browse Damage in September/October 2007 Site Est: Herb/shrub Cover Ground Hare Pellets per quadrat % Browse High Density % Browse Naturals + Controls 103p67-09 Elenor Lakes VH N/A 0 0 103p60-09 Mitten H 2 3 5 93m32-11 Salmon Road 11km H 4.67 40 22 93m42-36 Muldoe M 6.13 20 6 93m41-01 Helen Lake M 1.53 10 8 93m04 23 (Evelyn pasture) M 1.47 40 5 93m04 32 Blunt Creek M 0 0 0 103p70-17 A Pinpoint L 0.07 0 0 103p70-17 B Pinpoint L 0 0 0 103p86-11 Brown Bear L 1.8 0 0 103p86-15 95 km Hwy 37 L 0.53 0 0 93m04 35 (near Morice Town) L 1.07 0 0
Observed browse damage ~ 2 months after the initial browse survey 60 50 40 Percentage change in Browsing in the past ~50-60 days Browsed Naturals + Controls Browsed High Density Nursery seedlings 30 20 10 0 Helen 2nd October Helen 23rd November Muldoe 24th September Site and Date Muldoe 23rd November
Browse damage by seedling species Percentage Browse at Muldoe and Helen by seedling treatment (November 23rd 2007) (N = 128) 90 80 70 60 Controls Naturals High Density 50 40 30 20 10 0 Hemlock sub-alpine fir Spruce Cedar Tree Species
Severity of Browse Damage on Seedlings Percentage Browsing damage >50% in SX Trial sites Helen and Muldoe (November 23rd 2007) 90 80 70 60 50 Browse >50% of a seedling Browsed Jumbo >50% Browsed 40 30 20 10 0 Hemlock sub-alpine fir Spruce Cedar Tree Species
Ecosystem Change and Hare Population Dynamics
Mountain Pine Beetle/ Dothistroma and Hares Snowshoe Hare Habitat use in Winter 12 Hare Pellets per Quadrat 10 8 6 4 Hare Pellets per Quadrat 2 0 OF(Pl) OF(Sx) MF (Pl) 1975 (Pl) 1980 (Pl) 1983 (Pl) 1988 (Pl) Planted <10yrs Habitat Type and Age of Planting (Leading Species) Nadina Forest District
Acknowledgements Gitxsan and Wet'suwet'en First Nations MoFR FIA Kalum and Skeena-Stikine Forest Districts Silverwood Consulting Ltd. Wildlife Dynamics Consulting (doyle@bulkley.net) The hottest New Game Show in the Forest Who wants to eat a Million Hares.