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Week 1 Ecology Chapters 52-54. Dispatch—Make 3 observations on the distribution of biomes.

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Presentation on theme: "Week 1 Ecology Chapters 52-54. Dispatch—Make 3 observations on the distribution of biomes."— Presentation transcript:

1 Week 1 Ecology Chapters 52-54

2 Dispatch—Make 3 observations on the distribution of biomes

3 Goal and Name same side Line up for pic

4 Air Cells Descending air absorbs moisture Ascending air releases moisture

5 Group whiteboard Draw a mountain Predict what happens to air as it rises over a mountain

6 How mountains affect rainfall. RAINSHADOW 

7 Show the O2 and CO2 cycle Be as detailed as possible One person will be picked to present

8 Nitrogen cycle

9 Dispatch If your group needs to present  find a group to listen and approve you If your group is approved  listen to group’s nitrogen presentation  if they have all components, tell me

10 Nitrogen Cycle Animation f/pages/soilhealth_nitrogen-cycle

11 Population vs. Community

12 Population Ecology QUESTIONS: 1)What is a population? 2)What affects the size a population can get?

13 Population A population is a group of individuals of a single species that simultaneously occupy the same general area. Two characteristics that affect populations are ________ and _______

14 Population characteristics Density~ # of individuals per unit of area counts sample size estimate indirect indicators mark-recapture Dispersion~ pattern of spacing random~ unpredictable, patternless spacing (a) clumped~ patchy aggregation (b) uniform~ even spacing ( c)

15 Density is the result of a dynamic interplay –Between processes that add individuals to a population and those that remove individuals from it

16 Births and immigration add individuals to a population. BirthsImmigration PopuIation size Emigration Deaths Deaths and emigration remove individuals from a population.

17 Activity: Make a graph for a bacterial population and an elephant population



20 Dispatch—Get a textbook 1)Draw an exponential growth curve? What species exhibit this growth? 2)What about the environment would make an r species exhibit exponential growth? 3)Describe what a population’s carry capacity is and what it means to the population? 4)Compare and contrast density- dependent to density-independent factors? Take our calendar and tell your tablemates 3 upcoming deadlines Pick up a growth half sheet and a paper that says class set Wilderness Park 9:30 TOMORROW

21 Population Growth Models Exponential model (blue) idealized population in an unlimited environment (J-curve); r-selected species (r=per capita growth rate) Logistic model (red) carrying capacity (K): maximum population size that a particular environment can support (S-curve); K- selected species

22 Demography: factors that affect growth & decline of populations Birthrate (natality, fecundity)~ # of offspring produced Death rate (mortality) Age structure ~ relative number of individuals of each age Survivorship curve ~ plot of numbers still alive at each age

23 R vs. K survivorship curves

24 Population life history “strategies” r-selected (opportunistic) Short maturation & lifespan Many (small) offspring; usually 1 (early) reproduction; no parental care High death rate Ex:________ K-selected (equilibrial) Long maturation & lifespan Few (large) offspring; usually several (late) reproductions; extensive parental care Low death rate Ex :____________

25 Population limiting factors Density-dependent factors competition predation stress/crowding waste accumulation Density-independent factors weather/climate periodic disturbances

26 Community Ecology QUESTIONS: 1) What is a community? 2) Who are the members of this community? 3) What is a food chain?

27 Differences in Community structure Community ~ an assemblage of populations living close enough together for potential interaction. Many different ______. Communities differ dramatically in their species richness (number of species) & relative abundance of different species

28 How can we account for the species found together as members of a community? 2 Hypotheses: Individualistic~ all the species just happened to live in the same area b/c they all had similar abiotic requirements. Example they all needed same temperature, rainfall, soil type which is why they live in the same habitat. Interactive~ all the species are locked into association by mandatory biotic interactions. Species are found together b/c they have formed relationships +, - and o.

29 TASK: Add a column to the right and give an example of each type of interaction Between Species

30 Activity: Interaction Charades I will give your group an interaction and you act it out

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