Ecosystem Resistance and Resilience Considerable amount of literature supports idea that resilience is important for ecosystem restoration Lesson 4 Presentation 1

Rank the following species for protection Score 6 for 1 st priority Score 6 for 1 st priority Score 1 for last priority Score 1 for last priority

Lemon shark Jupiter Charter tours WWF Giant Panda Massassauga Rattlesnake Bebb’s willow Sea OtterGorilla Nat. Geog. US Nat Parks COSEWIC Unive Manitoba

Outline Definition of ecosystem resistance and resilience Definition of ecosystem resistance and resilience Use of these terms to evaluate natural and human events/activities Use of these terms to evaluate natural and human events/activities Ecosystem management Ecosystem management

Ecosystem Resistance Ability to resist change due to external event Ability to resist change due to external event Rubber band analogy: How much force needed to stretch the band Rubber band analogy: How much force needed to stretch the band

Ecosystem Resilience Resistance to disturbance and speed of return to equilibrium state Resistance to disturbance and speed of return to equilibrium state I.e. ability to “bounce back” I.e. ability to “bounce back” “Degree, manner, and speed of recovery of structure, composition and function of the original ecosystem after disturbance” “Degree, manner, and speed of recovery of structure, composition and function of the original ecosystem after disturbance” Rubber band: How quickly band returns to initial shape Rubber band: How quickly band returns to initial shape

How resilient? Resilience dependent on: Resilience dependent on:  Type, intensity and frequency of event  Site factors  Adaptation of life forms Important!

Name some natural events that cause changes in ecosystems  Wind events  Fire  Rain/storms  Floods/landslides  Ice/snow  Insects/Diseases  Age  Earthquakes/Volcanoes/Meteors

Terrestrial example

White pine forest Tree species Tree species  White pine, red pine, white spruce, balsam fir, aspen, white birch Plants Plants  Hazel, raspberries, dogwood

Adaptations of pines to fire thick bark crowns high above the forest floor roots deep in soil seeds do not store High resistance Moderate resilience

Adaptations of white birch and aspen Low resistance but high resilience Trees killed Resprout or sucker High/frequent seed production Light seed

Adaptations of Balsam fir & W. Spruce Thin bark, crowns low Thin bark, crowns low Seed not stored Seed not stored Balsam: Low resistance and resilience Balsam: Low resistance and resilience White spruce: Less flammable bark White spruce: Less flammable bark

Results after fire Large pine trees more likely to live Large pine trees more likely to live Some trees die (name species) Some trees die (name species) Some plants die Some plants die Some duff burned: nutrient flush Some duff burned: nutrient flush Require live trees to reproduce pine Require live trees to reproduce pine Seed dropped after fire likely to grow Seed dropped after fire likely to grow

Compare with historic logging Large conifers (pine& spruce) targeted for removal Large conifers (pine& spruce) targeted for removal Balsam fir & white birch left Balsam fir & white birch left Result: Result:  Less pine and spruce in new stands  More low quality stems  Less profit & jobs  Increase in insect & disease damage Low resistance and resilience for pine and spruce

Insect and disease of white pine white pine blister rust white pine weevil white pine: less pest damage in partial shade and with structure of natural forest white pine: less pest damage in partial shade and with structure of natural forest Alien species Native species

Current practices retain large seed bearing trees retain large seed bearing trees thin from below thin from below retain veteran trees retain veteran trees control competition control competition retain down woody debris, mast and cavity trees retain down woody debris, mast and cavity trees genetic diversity genetic diversity

How are current practices implemented? Crown Forest Sustainability Act and Environmental Assessment Declaration Order Crown Forest Sustainability Act and Environmental Assessment Declaration Order Guides that describe standards of practice Guides that describe standards of practice Training and certification Training and certification What else is required for you to know if this system is working/being applied correctly? What else is required for you to know if this system is working/being applied correctly?

Ecosystem management or emulation forestry The new practices are an example of stand level ecosystem management or emulation forestry The new practices are an example of stand level ecosystem management or emulation forestry Try to manage human activities to more closely match those of nature Try to manage human activities to more closely match those of nature RATHER THAN Try to manage ecosystems Try to manage ecosystems

Note: Source of Problem What is important for ecosystem restoration is what we leave behind What is important for ecosystem restoration is what we leave behind What is important for economics is what we remove What is important for economics is what we remove

Questions