Ecosystem Resistance and Resilience

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

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

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

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

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

6. Ecosystem Resilience • Resistance to disturbance and speed of return to equilibrium state • I.e. ability to “bounce back” • “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

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

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

9. Terrestrial example

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

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

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

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

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

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

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

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

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

19. 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 RATHER THAN • Try to manage ecosystems

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

21. Questions