[Ecolunch] Ecolunch Thursday 4/20

[Allen Hurlbert]

Please join us for this week's NCEAS Ecolunch seminar on Thursday, April 20th at 12:15 p.m. Our speaker will be Dr. Egbert Leigh, staff scientist at the Smithsonian Tropical Research Institute in Panama. The title of his talk is "The role of mathematical theory in tropical forest ecology". An abstract of his talk follows below.

Allen


ABSTRACT
  Trees interact primarily with near neighbors, so mathematical theory of forest ecology should be an interactive dyamics of spatial arrangements of trees of different species. Cruder theory, however, is useful. It predicts
 1. trees' competition for light causes uneven distribution of light over leaves, slashing gross forest production,
 2. competition for nutrients favors fine-root investment far beyond what maximizes forest wood production,
 3. soil quality affects lowland tropical forest productivity far less than above vs below-ground allocation, 
 4. on poorer soils, trees and leaves live longer, 
 5. stronger, denser wood increases tree lifetime. Long-lived leaves must not be eaten or dry out. Such leaves are tougher; they are adapted to limit stomatal conductance (thereby limiting photosynthetic capacity).
  Testing neutral theory's prediction of how fast initially rare species can spread shows that two clades colonizing South America from overseas 20 MY ago spread non-randomly quickly. They did not oust other clades: tropical tree species must coexist because they are limited by different factors.
  Finally, one cannot understand tropical forest without considering animals and pathogens. Lotka-Volterra equations suggest that
 1. Trees can reduce herbivory by more effective defense, which slows growth, or by being rare,
 2. many tree species coexist if specialist pests keep each one rare, as appears true in most tropical forests,
 3. predators consume more herbivores in more productive forest, showing why employing animals as pollinators and seed dispersers allowed diverse, productive flowering forest to replace better-defended, slower-growing gymnosperms.



GENERAL INFORMATION Ecolunches are Thursdays, at 12:15 pm (Brown Bag Lunch) National Center for Ecological Analysis and Synthesis, 735 State St., Suite 300, Santa Barbara, CA 93101 Phone: (805) 892-2500

DIRECTIONS FROM UCSB BY BUS: You can get to NCEAS by taking the 11:40 a.m. bus (# 24x) from campus. From the transit center, walk one block east to State Street and two blocks south to the Balboa Building at 735 State Street. To return to campus, you can take the 1:30 p.m. bus (#24x) from the transit station and be back on campus by 1:49 p.m. Or you can take the 2:20 p.m. bus and arrive on campus at 2:39.

BY CAR: take Highway 101 South. Once in Santa Barbara, exit on Carrillo Street. Turn left onto Carrillo. Drive 5 blocks and turn right on State Street. NCEAS is located on the right side at 735 State St., Suite 300. To Park: Drive past NCEAS on State Street and make your first right on Ortega Street. Drive 1 block and turn right on Chapala Street. Park in the underground Mall parking lot on your right. (First 75 minutes free). Once you are at the Balboa Building: We are on the third floor in the lounge area.