UCSB EEMB 171 - Lecture 4-5 2015 (3) (84 pages)

Previewing pages 1, 2, 3, 4, 5, 6, 39, 40, 41, 42, 43, 79, 80, 81, 82, 83, 84 of 84 page document View the full content.
View Full Document

Lecture 4-5 2015 (3)



Previewing pages 1, 2, 3, 4, 5, 6, 39, 40, 41, 42, 43, 79, 80, 81, 82, 83, 84 of actual document.

View the full content.
View Full Document
View Full Document

Lecture 4-5 2015 (3)

95 views


Pages:
84
School:
University of California, Santa Barbara
Course:
Eemb 171 - ECOSYSTEM PROCESSES

Unformatted text preview:

e g Nitrate leaching Response RESISTANCE versus RESILIENCE Resistant little response Resilient rapid recovery Time Systems are rarely both resistant and resilient Why Once a resistant system is perturbed recovery often slow Resilient systems are often easy to perturb RESISTANCE versus RESILIENCE Starting Point Starting Point Low Resilience High Resilience Low Resistance High Resistance Grasslands burn often limited impact recover quickly RESISTANCE versus RESILIENCE Forests burn rarely huge impact recover slowly Tea Fire November 13 2008 Photo November 22 RESISTANCE versus RESILIENCE One year later December 30 2009 How can resistance resilience be different in a single system RESISTANCE versus RESILIENCE secondary succession in northern hardwoods NO3 leaching Species Hardwoods Pin Cherry 0 5 50 By considering different ecosystem processes 200 How can resistance resilience be different in a single system High Global Stability Stratified Lakes RESISTANCE versus RESILIENCE Tropical Forest SW Grasslands Low Low Local Stability High Ecosystem controls on RESISTANCE RESILIENCE What controls stability Role of community composition How does the diversity of the community affect stability Stability vs Diversity Instability of species may stabilize processes Ecosystem controls on RESISTANCE RESILIENCE Plant diversity can regulate soil nutrient availability system productivity Ecosystem controls on RESISTANCE RESILIENCE Productivity of tundra plant communities across years with different weather patterns Average Temp Precipitation Year 1968 1969 1970 Variability 15 1 14 7 12 9 51 90 88 147 25 Total Production Sedges Deciduous shrubs Evergreen shrubs 65 3 14 3 8 3 35 7 77 4 10 7 13 9 47 3 74 6 27 6 11 2 22 0 8 8 50 25 36 From Chapin and Shaver 1985 Ecology 66 564 576 Approaches to studying ecosystem dynamics Two basic approaches 1 Input output budgets 2 Mechanistic analysis Budget measurements at the ecosystem level descriptive Essentially these are top down and bottom up perspectives in the hierarchy of scales ecosystem measurement approaches whole system measurements containerize the system soil respiration by point measurements strengths and limitations of technique ecosystem respiration by eddy flux towers Small vertical eddies in the air carry heat water and gases to and from the ground surface Measure vertical windspeed carbon dioxide CO2 etc source http upload wikimedia org wikipedia en 1 11 EddyCovariance diagram 1 jpg measuring water nutrients weirs measure water flow extrapolation Measure multiple sites and then multiply out to the total area of the site Variability Tension in ecosystem science Questions are about big picture so require integration but also require mechanism which is reductionist Strengths limitations of approaches to studying ecosystems Budgeting Field measurements Strengths Real data on field processes Limitations Non mechanistic scale strengths limitations of approaches to studying ecosystems with mechanistic analysis Strengths



View Full Document

Access the best Study Guides, Lecture Notes and Practice Exams

Loading Unlocking...
Login

Join to view Lecture 4-5 2015 (3) and access 3M+ class-specific study document.

or
We will never post anything without your permission.
Don't have an account?
Sign Up

Join to view Lecture 4-5 2015 (3) and access 3M+ class-specific study document.

or

By creating an account you agree to our Privacy Policy and Terms Of Use

Already a member?