Snowshoe Hare browsing damage on seedling trees underplanted in Dothistroma and MPB attacked stands

Transcription

1 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 / ~ doyle/ Snowshoe Hare impacts on seedlings Strategies to reduce the damage on seedlings Ecosystem Change and Hare Population Dynamics

2 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

3 Dothistroma M.P.B

4 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.

5 Snowshoe Hare impacts on seedlings Underplanted seedling browsing damage observed 1 month post planting (Dunkley, Prince George): Dow & Danskin Douglas Fir Pine Spruce (%) % Seedlings Damaged Hares Ungulates Voles Damage and species responsible

6 Ecosystem Impacts of Hare Browsing Kluane, Yukon

7 Strategies to reduce the damage on seedlings Cover removal Trials - Established in 2006 to determine if the removal of the dead/dying 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?

8 Removing Cover to protect Seedlings Palatability of different tree species Kispiox 2006 Spruce for breakfast

9 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

10 Percentage Browse in control and adjacent cleared areas with each Trial Unit Control Cleared Unit A Unit B Unit D Suskwa No Cattle Trial Units Free Range Cattle

11 Relationship between browsing and the number of hare pellets Seedlings Browsed (%) Regression 95% confid Hare Pellets per Quadrant

12 Relationship between browsing and herb/shrub coverage in cleared Areas 40 Seedlings Browsed (%) Potential Threshold in Cover? 5 0 Regression 95% confid Herb-Shrub Cover (> 0.5m high)

13 Percentage of Seedlings with Browse Damage Hemlock sub-alpine fir Spruce Units A, B & D Cleared No Cattle Units A, B & D Control Site Type Suskwa Cleared Suskwa Control Free Range Cattle

14 Percentage of Seedlings with >50% of overall browse damage Hemlock sub-alpine fir Spruce Units A, B & D Cleared No Cattle Units A, B & D Control Site Units Suskwa Cleared Suskwa Control Free Range Cattle

15 Tree Shelter and Alternative Planting Strategy Trial - Seedling protection, seedling density, seedling type Brown Bear October 2007

16 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.

17 Trial Layout = 90 sample pods (High density planting per ha) 75 cm Trial Block Layout Jumbo Spruce

18 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 p60-09 Mitten H m32-11 Salmon Road 11km H m42-36 Muldoe M m41-01 Helen Lake M m04 23 (Evelyn pasture) M m04 32 Blunt Creek M p70-17 A Pinpoint L p70-17 B Pinpoint L p86-11 Brown Bear L p km Hwy 37 L m04 35 (near Morice Town) L

19 Observed browse damage ~ 2 months after the initial browse survey Percentage change in Browsing in the past ~50-60 days Browsed Naturals + Controls Browsed High Density Nursery seedlings Helen 2nd October Helen 23rd November Muldoe 24th September Site and Date Muldoe 23rd November

20 Browse damage by seedling species Percentage Browse at Muldoe and Helen by seedling treatment (November 23rd 2007) (N = 128) Controls Naturals High Density Hemlock sub-alpine fir Spruce Cedar Tree Species

21 Severity of Browse Damage on Seedlings Percentage Browsing damage >50% in SX Trial sites Helen and Muldoe (November 23rd 2007) Browse >50% of a seedling Browsed Jumbo >50% Browsed Hemlock sub-alpine fir Spruce Cedar Tree Species

22 Ecosystem Change and Hare Population Dynamics

23 Mountain Pine Beetle/ Dothistroma and Hares Snowshoe Hare Habitat use in Winter 12 Hare Pellets per Quadrat 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

24 Acknowledgements Gitxsan and Wet'suwet'en First Nations MoFR FIA Kalum and Skeena-Stikine Forest Districts Silverwood Consulting Ltd. Wildlife Dynamics Consulting The hottest New Game Show in the Forest Who wants to eat a Million Hares.