TAKING THE PULSE OF MOUNTAIN FORESTS: (CORFOR) THE CORDILLERA FOREST DYNAMICS NETWORK. U.S. Department of the Interior U.S.

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1 TAKING THE PULSE OF MOUNTAIN FORESTS: THE CORDILLERA FOREST DYNAMICS NETWORK (CORFOR) U.S. Department of the Interior U.S. Geological Survey

2 CORFOR is a collaboration of scientists with permanent forest study plots arrayed along the American Cordillera

3 Nate Stephenson U.S. Geological Survey, USA Alvaro Duque Univ. Nacional de Colombia, Medellín Esteban Alvarez Interconexión Eléctrica S.A., Colombia Julieta Carilla Univ. Nacional de Tucumán, Argentina Lori Daniels Univ. of B.C., Vancouver, Canada Ricardo Grau Univ. Nacional de Tucumán, Argentina Greg Greenwood Mountain Res. Initiative, Switzerland Mark Harmon Oregon State Univ., Corvallis, USA Sergio Orrego Univ. Nacional de Colombia, Medellín Phil van Mantgem U.S. Geological Survey, USA Tom Veblen University of Colorado, Boulder, USA

4 Road map: Part 1: Information needs: mountain forests in a changing climate Part 2: Permanent forest plots uniquely meet some of our information needs Part 3: Need for, and birth of, the Cordillera Forest Dynamics Network (CORFOR) Part 4: CORFOR progress report

5 Mountain forests provide: Wood and other products Hydrologic regulation Recreational and spiritual opportunities Critical wildlife habitat and biodiversity conservation

6 Mountain forests provide: Wood and other products Hydrologic regulation Recreational and spiritual opportunities Critical wildlife habitat and biodiversity conservation With rapid climatic change, we potentially face: Changes (included losses) in some of these goods and services Large feedbacks to climatic change

7 If we hope to adapt to and mitigate the effects of climatic changes on forests, we have at least two critical needs: (1) Ability to detect ongoing changes. (2) Ability to forecast future changes.

8 2. PERMANENT FOREST PLOTS UNIQUELY MEET SOME OF OUR INFORMATION NEEDS Change detection: Hicke et al. 2002, Global Biogeochem. Cycles

9 Change detection: Advantages of remote sensing: Wall-to-wall coverage across a range of spatial scales! Need for plot-based data: Ground-truthing of remotely-sensed data Detecting things not detected by remote sensing - Changes in reproduction - Subtle changes in mortality rates - Ongoing compositional shifts The two approaches are complementary!

10 Tropical (Amazonian) forest DYNAMICS are changing (e.g., recruitment, growth, and mortality rates are increasing) Recruitment Mortality Phillips et al., Phil. Trans. B, 2004

11 Tropical (Amazonian) forest COMPOSITION is changing (e.g., lianas [woody vines] are increasing) Credit: Yadvinder Malhi Phillips et al., Nature, 2002

12 Tropical (Amazonian) forest STRUCTURE AND FUNCTION are changing (e.g., aboveground biomass, hence C storage, may be increasing) Basal area gain Basal area loss Difference Lewis et al., Phil. Trans. B, 2004

13 Temperate (western USA) forest DYNAMICS are changing (background mortality rates are increasing) Mortality rate (% yr -1 ) P<0.0001, n= Year van Mantgem et al. 2008

14 Temperate (western USA) forest COMPOSITION is changing (e.g., 5-needled pines are declining) PILA population size observed projection using data projection using data projection using data Year van Mantgem et al. Ecol. Appl. 2004

15 Temperate forest STRUCTURE AND FUNCTION are almost certainly changing, but

16 Temperate forest STRUCTURE AND FUNCTION are almost certainly changing, but Trust us, George we re working on it!

17 Change detection: Permanent forest plots provide our Keeling curve for forests

18 Most current models are driven by sets of untested assumptions, many of which are decades old. Forecasting:

19 The well-known inverse relationship between tree growth rate and probability of death is at the heart of gap models. Probability of death Growth rate

20 A key model assumption: The only way climatic changes affect probability of death (in the absence of catastrophic disturbance) is by altering tree growth rate. Probability of death Growth rate

21 How do we test assumptions like this when the great spatial and temporal scales of forest dynamics preclude experimentation? Replicated mountain forests in bell jars

22 We take advantage of natural experiments in space and time permanent forest plots arrayed along environmental gradients Credit: A. Caprio

23 In the forests of California s Sierra Nevada, forest turnover rate (mortality and recruitment) declines significantly with elevation. Forest turnover (% yr -1 ) y = x r 2 = 0.49, P < Elevation (m) Stephenson & van Mantgem, Ecol. Lett., 2005

24 Globally, forests of productive environments have higher turnover rates... at least partly because environments that favor tree growth also favor the organisms that kill trees. Forest turnover (% yr -1 ) Forest turnover (% yr -1 ) Tropical Temperate 0 Richer soils Poorer soils Angiosperm Mixed Gymnosperm Tropical Temperate (Amazonia) (global) Stephenson & van Mantgem 2005

25 Natural experiments in space suggest the need for a fundamental change in the nature of the gap model mortality function. Mortality rate Site productivity Low High Low High Individual tree growth rate

26 Summary: some roles of permanent forest plots Mortality rate (% yr -1 ) (1) Change detection 2.0 P<0.0001, n= Year Mortality rate (2) Provide a mechanistic foundation for forecasting Site productivity Low High Low High Individual tree growth rate

27 3. NEED FOR, AND BIRTH OF, THE CORDILLERA FOREST DYNAMICS NETWORK (CORFOR) Only two other broad, international forest dynamics networks exist, and both focus on lowland tropical forests The RAINFOR plot network

28 The Center for Tropical Forest Science (CTFS) plot network

29 CORFOR s vision: a network taking advantage of the broadest environmental gradients possible

30 CORFOR s vision: a network taking advantage of the broadest environmental gradients possible Latitudes: Subarctic temperate tropical (and back). Temperature (elevation): Sea level to >3500 m. Precipitation: West-to-east gradients. Soils and topography: Local variation.

31 Based on this vision, CORFOR was born at the CONCORD climate change conference in Mendoza, Argentina, 4-6 April 2006

32 4. CORFOR PROGRESS REPORT CORFOR workshop, 13 June 2008, thanks to: - Mountain Research Initiative (MRI), Switzerland - USGS Western Mountain Initiative (WMI) - MTNCLIM 2008 organizers

33 Among other things, tomorrow s workshop will: - Establish a set of minimum standards for forest dynamics plots in the network. - Create a road map for the future: identify research needs and opportunities of broad significance that CORFOR can address. - As a proof of concept, work on a paper comparing forest dynamics along elevational gradients in the southern temperate zone, tropics, and northern temperate zone.

34 Northern temperate zone: California, Oregon, and Washington plot networks

35 Mortality rate vs. elevation, northern temperate zone Mean mortality rate (% yr -1 ) California R 2 = 0.54, P < Elevation (m)

36 Mortality rate vs. elevation, northern temperate zone California Oregon & Washington Mean mortality rate (% yr -1 ) R 2 = 0.54, P < Mean mortality rate (% yr -1 ) R 2 = 0.08, P = Elevation (m) Elevation (m)

37 Tropics: Colombian plot network... 5-ha 25-ha 2-ha 1-ha

38 Mortality rate vs. elevation, tropics Mean mortality rate (% yr -1 ) Colombia R 2 = 0.31, P = Elevation (m)

39 Mortality rate vs. elevation, tropics Colombia Venezuela Mean mortality rate (% yr -1 ) R 2 = 0.31, P = Elevation (m) Mean mortality rate (% yr -1 ) R 2 = 0.09, P = Elevation (m)

40 Southern temperate zone: Tucumán, Argentina plot network

41 Mortality rate vs. elevation, southern temperate zone Mean mortality rate (% yr -1 ) Argentina, mature forest R 2 = 0.08, P = Elevation (m)

42 Mortality rate vs. elevation, southern temperate zone Mean mortality rate (% yr -1 ) Argentina, mature forest R 2 = 0.08, P = Mean mortality rate (% yr -1 ) Argentina, secondary forest R 2 = 0.20, P = Elevation (m) Elevation (m)

43 CORFOR Challenges: Time: All of us have many other pressing obligations. Funds: It is very difficult to capture funds for longterm forest research, much less to hire someone to coordinate CORFOR activities. Communication: We are literally continents apart. We accomplished more in a few hours together yesterday than we had during weeks of exchanges.

44 CORFOR Challenges: Time: All of us have many other pressing obligations. Funds: It is very difficult to capture funds for longterm forest research, much less to hire someone to coordinate CORFOR activities. Communication: We are literally continents apart. We accomplished more in a few hours together yesterday than we had during weeks of exchanges. Happily, we have a dedicated, motivated, and excited core group of scientists, ready to accept these challenges.

45 Thank you for your attention!