1. 5) The distribution of terrestrial biomes is based mainly on regional variations in climate. 1) Interactions between organisms and environment determine distribution and abundance: dispersal, habitat selection, biotic factors, abiotic factors (climate very important: temperature and water). 2) Temporal and spatial scales of studies are important. 3) Global climate mostly determined by solar energy and earth’s movement in space. Permanent tilt on Earth’s axis causes seasonal variation in light, temperature and wind patterns. Hence, seasonal variation in distribution and abundance of organisms. 4) Aquatic biomes occupy the largest part of the biosphere; oceans have a major effect on global and local climate; freshwater biomes are closely linked to terrestrial biomes.

2. Aquatic Biomes Largest component. Vertical stratification: light, temperature, salinity, density. Oceans (3% salt): rainfall, climate, wind. Give O 2 and take CO 2. Freshwater (< 1% salt): linked to soil and biota of terrestrial biomes. Fig. 50.17 pages 1106-1109

3. Ocean zonation Distance to shore & water depth, light penetration, substrate. pages 1109-1112 Fig. 50.22

4. Terrestrial Biomes Determined by climate: latitudinal and regional patterns. Vertical stratification based on vegetation. Characteristic life forms. Gradation in boundaries: ecotone. Dynamic, not stable. pages 1112-1113 Fig. 50.24

5. 1- Are we going to be tested on material that you have not covered in lecture? SOME questions from February 8th 2- When will the review sheet be posted? Will we have a study/review session? 3- Will there be questions about the third article on the test? 6- What are the lowest points in the ocean? What could possibly live there? 4- Do any chemicals evaporate with water or does water always separate from anything it is mixed with? 5- What is the Ekman transport vector? Why is it important?

6. Organismal ecology coping Population ecology limiting factors Community ecology interspecific interactions and diversity Ecosystem ecology energy flow and chemical cycling Landscape ecology effects on interactions at lower levels Biosphere ecology global effects Chapter 52- Population Ecology

7. Population: Group of individuals of the same species occupying the same general area. 67,171- 2000 Census 71,080- 2004 Estimate Density. Dispersion. pages 1151-1152

8. Uniform Clumped Random Fig. 52.2 page 1153 Dispersion Patterns

9. Additions (+) Natality (births). Immigration. Changes in Population Size Demography: Studies vital statistics that affect population size. pages 1153 (1154) Life Histories pages 1156-1158 Reproductive success. Number of surviving offspring produced by an individual and that reach reproductive age. Natural selection. Differences in reproductive success due to heritable differences in individuals. Life histories. Patterns of resource allocation to maintenance (survival), growth, and reproduction. Subtractions (-) Mortality (deaths). Emigration. Individuals expected to behave so as to promote their own RS. Fig. 52.5 Island of Rhum, Scotland

10. TID Three basic life history “decisions” (remember not conscious choice except us): -When to begin reproducing? -How often to breed? -How many offspring to produce during each reproductive episode? Life Histories Iteroparity. Semelparity (“once” and “beget”) (“repeat” and “beget”) page 1156

11. Population Growth population is growing ( >1 ) population is declining ( <1 ) zero population growth ( 1 ) λ = number of individuals at time t + 1 divided by number of individuals at time t Finite rate of increase population is growing ( r+ ) population is declining ( r- ) zero population growth ( r = 0 ) r = ln λ Instantaneous rate of change 115100 115 100 NtNt+1 λ r% change 100 1.150.1415 0.87-0.14-13 pages 1158-1159

12. Exponential model Population Growth r max = maximum growth rate for the species Intrinsic rate of growth rate dtdt dNdN = r max N Ideal conditions: population growth constrained only by life history. exponential population growth or geometric population growth pages 1159-1160

13. Logistic model There is a limit to number of individuals that can occupy a habitat. Carrying capacity (K). Maximum population size an environment can support at a time with no habitat degradation. Not a fixed value. Population growth rapid when population size well below K, slow when close to K and zero when at K. Population Growth K K - N K = 100; N = 1; (K-N)/K = 0.99 K = 100; N = 90; (K-N)/K = 0.1 K = 100; N = 100; (K-N)/K = 0 dtdt dNdN = r max N K K - N pages 1160-1161

14. Number of individuals Time r = 0.02 Population Growth S-shaped curve. Population growth levels off as population size approaches carrying capacity. r = 0.02 Exponential curve. Population grows indefinitely. pages 1161-1162

15. ICES J. Mar. Sci. 2003 Halichoerus grypus J. Wildl. Manage. 2003 Phoca vitulina Sable Island, CAN pages 1162-1163

16. Many factors cause changes in birth and death rates in relation to population density: increased predation, competition for food or space, stress, parasitism, etc; slowing population growth rate. Population-Limiting Factors Why do they represent an example of negative feedback? Food-limited pages 1164-1165 Fig. 52.14 CRESLI Eubalaena glacialis Mandarte Isl., BC

17. Dynamics of Populations They result from the interaction between biotic and abiotic factors. Long-term studies indicate that such factors make natural populations unstable. Fig. 52.17 pages 1165-1167 Assigned paper to read for Quiz IV. Isla Royale, Michigan

18. -Hare fluctuations. -Fluctuations of food species. -Predation by various species. Some populations have regular boom-and-bust cycles. Fig. 52.19 pages 1167-1168 -Geographic variations due to large- scale climate effects (apparent lack of lynx migration between regions). PNAS 2004