midterm Scores Quantile Value 25% 68 median 81 75% 88

Transcription

1 midterm # Quantile Value 25% 68 median 81 75% Scores Scores are on Blackboard: if you want the test back you need to see me in my office, Tuesday 1:45-5pm,Wednesday 2-3pm, or by appointment 1

2 Essay writing Title of essay One paragraph why you write about the chosen topic. Due date: the sooner the better [I will respond to your ] 2

3 Most common problems Species, population, individual mixing Genetics with PVA structured PVA problems 3

4 Species interactions Community The number of bumblebees in any district depends in a great measure upon the number of field-mice, which destroy their combs and nests. [Because] the number of mice is largely dependent, as everyone knows, on the number of cats... It is quite credible that the presence of a feline animal in large numbers in a district might determine, through the intervention first of mice and then of bees, the frequency of certain flowers in that district! Charles Darwin: The Origin of Species by means of Natural Selection, 6th Edition,

5 Cats Mice Plants Bumblebees 5

6 Cats Mice Plants Bumblebees 6

7 Species interaction grid Species Species 2-7

8 Species interaction grid Species Mutualism Predation Herbivory Disease Species 2 - Predation Herbivory Disease Competition 8

9 Predation Cats Mice Plants Bumblebees 9

10 Cats Mice Mutualism Plants Bumblebees 10

11 Competition Cats Hawks Mice Plants Bumblebees 11

12 Indirect effect Cats Mice Plants Bumblebees 12

13 Examples of species interactions: Competition House gecko introduced to Pacific islands where there is a native gecko (mourning gecko) 13

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15 Examples of species interactions: Mutualism fig trees fig wasps 750 species of figs most with a single species of pollinator 15

16 Examples of species interactions: Predation Wolves increased since reintroduction 16

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18 Wolves Coyotes Elk Pronghorn Plants Effect of introduction of wolves on plants and elks? 18

19 Keystone species Species with a disproportionate effect on community structure Total effect Keystone Dominant Abundance 19

20 What explains the total diversity in a community? Keystone species can influence diversity Equilibrium theory of island biogeography 20

21 Structured populations Mainland Island Stepping Stone model Metapopulation Subpopulation 21

22 Metapopulations Metapopulation Subpopulation A population of local populations which are established by colonists, survive for a while, send out migrants and eventually disappear. 22

23 Classic metapopulation model Habitat patches are discrete All populations have a substantial (and equal) risk of extinction Equal dispersal among all patches Dispersal fairly rare Ignore population dynamics within a patch 23

24 Extinction (E) and Colonization (C) E probability that an occupied patch will go extinct. C probability that an unoccupied patch will be recolonized 24

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26 Classical metapopulation model Rate Fraction of patches occupied 26

27 Classical metapopulation model Rate Colonization Extinction Equilibrium metapopulation size Fraction of patches occupied 27

28 Classical metapopulation model Metapopulation size is the number of occupied patches! occupied patches are a function of balance of extinction and colonization E > C? E = C? E < C? 28

29 Classical metapopulation model Metapopulation size is the number of occupied patches! occupied patches are a function of balance of extinction and colonization E > C E = C E < C metapopulation declines metapopulation is stable metapopulation grows 29

30 Metapopulation example Glanville Fritillary Melitaea cinxia Photograph by Alan Barnes 30

31 Classic metapopulation model Habitat patches are discrete All populations have a substantial (and equal) risk of extinction Equal dispersal among all patches Dispersal fairly rare Classic metapopulation not all that common, but some metapopulation ideas apply to many real systems 31

32 Metapopulation ideas important for conservation Migration between patches can help species persistence Some species require multiple patches of habitat Multiple patches can spread the risk of stochastic extinction Empty patches are important 32

33 Source - sink metapopulations Habitat patches vary in quality Source has a high quality habitat Sink has a low quality habitat Dispersal λ 1 Source Sink λ < 1 33

34 Source - sink metapopulations Rescue effect: sink population go extinct without immigration from sources. The source rescues the sink. Dispersal λ 1 Source Sink λ < 1 34

35 Source - sink metapopulations Source-sink relationships are defined by growth rate, NOT population size N c = 50 λ 1 Source Dispersal Sink N c = 200 λ < 1 35

36 Island biogeography Theory describing the diversity in a community as a function of extinction and colonization 36

37 Mainland Island Number of species = P Number of species = S 37

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39 Colonization versus Extinction Rate Colonization, the rate at which new species are gained Extinction, the rate at which island species are lost Equilibrium island species number 0 S Number of island species 39

40 Island biogeography and metapopulations Island biogeography Metapopulations Balance of E and C Balance of E and C Number of species in a patch Number of patches occupied 40

41 Area effects 41

42 Area effects How does island area affect the number species on the island? How does size affect extinction rate? S s C E s E l Rate P S l Island species number 42

43 Area effects How does island area affect the number species on the island? How does size affect extinction rate? P S s Rate S small < S large C E s E l S l S l S s Island species number 43

44 Area effects How does island area affect the number species on the island? How does size affect colonization rate? S small < S large S s Rate C l E s E l P C s S l S l S s Island species number 44

45 Bird species in the Lesser Antilles (D. Lack's data) 45

46 Distance effects 46

47 Distance effects How does distance from the mainland affect the number species on the island? How does size affect colonization rate? S far < S near E S n Rate C f C n S n P S f isn S S f 47

48 Bird species in the Lesser Antilles (D. Lack's data) 48

49 Dan Simberloff (a former FSU Biology Sciences member) 49

50 Test of the Equilibrium theory of island biogeography (ETIB) Experimental Zoogeography of Islands: The Colonization of Empty Islands, by Daniel S. Simberloff, Edward O. Wilson Ecology

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52 E2: closest to mainland E1: farthest from mainland 52

53 Contribution of ETIB for conservation biology Reserve = island Rules for reserve design Hanski, I. A., and G. M.E., editors Metapopulation biology: ecology, genetics, and evolution. San Diego, CA: Academic Press. 512 p. 53

54 Island Biogeography and Reserve rules: IUCN, UN,WWF better worse Bigger is better Connectivity is good One large is better than several small Less edge is better 54