OUR Ecological Footprint - 2 1. Recycle; pay tax for it. 2. This week lab: Due: Homework 9: Pop. Problem Set Start: SDP-2 Read paper about project Xerox Abstract/Intro for group members + TA
This week lab: Due: Homework 9: Pop. Problem SetStart: SDP-2 Read paper about project Xerox Abstract/Intro for group members + TA
Complete Proposal WS 1 in labTo be returned by TA: Draft 1 SDP1Following week’s lab: Due: Draft 2 SDP1
predators to prey
Birds, especially warblers, are primary predators of the insect spruce budworm, an invading pest of boreal forests. The ability of the predators to control these prey during a huge outbreak of the budworm was monitored.
2) Warblers also show a numerical response to increasing prey density. Illustrate this response in Fig. B.
(On all three figures, the x axis label is:
No. of insects/0.9m2 leaves
Fig. A: y axis = No. of insects/stomach
Fig B: y axis = No. nesting pairs/100 acres
Fig C: y axis = Mortality due to predators (%).
The curve in Fig. C goes sharply up at low density and slowly falls as density increases.
Do prey control predators or vice versa?
3) Spatial heterogeneity --->stable cycles.
to prey density
density (predator satiation)
Predator satiation of prey--->prey survived longer. individual predators, then numerical response in population size of predation via population growth or immigration.
*** prey--->prey survived longer.Is there a functional response? Numerical response? What is the total response of warblers to spruce budworm abundance? Does the warbler control its prey?
predators to prey
The figure below illustrates the distribution of two species of buttercups along a transect across ridge (high land) and furrow (low valley) grassland.
Sp 1 peaks on furrow (F)
Sp 2 peaks on ridge (R )
F R F R F Distance along transcect (m)
Superior competitor persists at lower resource levels.
Limits resources for growth, lx, mx.
D-D regulation of births, deaths--->
4) Population growth rate slows.
Competition may occur through prey--->prey survived longer.exploitation (indirect) of shared resources or (direct) interference(individuals defend resources actively).
Negative plant responses:
***What is the evolutionary consequence of a size hierarchy?
What is one assumption?
Competition results in
decelerating growth rate