1 / 35

Community Interactions and Ecological Dynamics

Explore the complex web of interspecific interactions, competition, predation, and mutualism in community ecology. Learn about niche differentiation, resource partitioning, and the impacts of dominant and keystone species on community structure and dynamics.

marioncooper
Download Presentation

Community Interactions and Ecological Dynamics

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chapter 53 Community Ecology

  2. I. Interspecific Interactions • Competition • Competitive exclusion principle • Niche – fundamental vs. realized • Resource partitioning • Character displacement • Predation • Adaptations • Cryptic coloration • Aposemetic coloration • Mimicry

  3. Table 53-1

  4. LE 53-2 High tide High tide Chthamalus Chthamalus realized niche Balanus Chthamalus fundamental niche Balanus realized niche Ocean Ocean Low tide Low tide

  5. A. insolitus usually perches on shady branches. LE 53-3 A. ricordii A. insolitus A. distichus perches on fence posts and other sunny surfaces. A. aliniger A. christophei A. distichus A. cybotes A. etheridgei

  6. G. fortis G. fuliginosa Beak depth LE 53-4 Santa María, San Cristóbal Sympatric populations 40 20 0 Los Hermanos Percentage of individuals in each size class 40 G. fuliginosa, allopatric 20 0 Daphne 40 G. fortis, allopatric 20 0 14 10 16 12 8 Beak depth (mm)

  7. Figure 53-05

  8. Figure 53-06

  9. LE 53-7 Green parrot snake Hawkmoth larva

  10. LE 53-8 Cuckoo bee Yellow jacket

  11. Herbivory • Parasitism • Endoparasites, ectoparasites and parasitoidism • Disease - pathogens • Mutualism • Commensalism

  12. II. Dominant and Keystone Species and Control of Community • Species diversity • Species richness • Relative abundance • Trophic structure • Food webs (Fig. 53.13) • Limits on length • Energetic hypothesis • Dynamic stability hypothesis

  13. A B LE 53-11 C D Community 1 C: 25% A: 25% D: 25% B: 25% Community 2 C: 5% A: 80% D: 10% B: 5%

  14. Quaternary consumers LE 53-12 Carnivore Carnivore Tertiary consumers Carnivore Carnivore Secondary consumers Carnivore Carnivore Primary consumers Herbivore Zooplankton Primary producers Plant Phytoplankton A terrestrial food chain A marine food chain

  15. Humans LE 53-13 Smaller toothed whales Sperm whales Baleen whales Elephant seals Leopard seals Crab-eater seals Fishes Squids Birds Carnivorous plankton Euphausids (krill) Copepods Phyto- plankton

  16. LE 53-14 Sea nettle Juvenile striped bass Fish larvae Zooplankton Fish eggs

  17. LE 53-15 6 6 No. of species 5 5 No. of trophic links 4 4 Number of species Number of trophic links 3 3 2 2 1 1 0 0 Medium Low High (control) Productivity

  18. Species with a Large Impact • Dominant species • Keystone species (Fig. 53.16, p. 1168) • Foundation species • Bottom-Up and Top-Down Controls • Bottom-Up: NVHP • Nutrients are limiting factors • Top-Down: NVHP • Predation is limiting factor

  19. LE 53-16 With Pisaster (control) 20 15 Number of species present Without Pisaster (experimental) 10 5 0 ’71 ’73 ’70 1963 ’66 ’68 ’69 ’72 ’64 ’65 ’67

  20. 100 LE 53-17 80 60 Otter number (% max. count) 40 20 0 Sea otter abundance 400 300 Grams per 0.25 m2 200 100 0 Sea urchin biomass 10 8 Number per 0.25 m2 6 4 2 0 1972 1989 1993 1997 1985 Year Total kelp density Food chain after killer whales started preying on otters Food chain before killer whale involvement in chain

  21. Figure 53-18

  22. 8 LE 53-19 6 Number of plant species 4 2 0 With Juncus Without Juncus Salt marsh with Juncus (foreground) Conditions

  23. 100 LE 53-20 75 Percentage of herbaceous plant cover 50 25 0 100 200 0 300 400 Rainfall (mm)

  24. LE 53-UN1171 Restored State Polluted State Rare Fish Abundant Abundant Rare Zooplankton Algae Rare Abundant

  25. III. Disturbance Influences Communities • Definition and causes • Changes in community and removal of species • Human roles • Ecological succession • Primary • Secondary

  26. LE 53-21 During the burn. The detritus serves as fuel for fires. Before a controlled burn. A prairie that has not burned for several years has a high propor-tion of detritus (dead grass). After the burn. Approximately one month after the controlled burn, virtually all of the biomass in this prairie is living.

  27. LE 53-22 Soon after fire. As this photo taken soon after the fire shows, the burn left a patchy landscape. Note the unburned trees in the distance. One year after fire. This photo of the same general area taken the following year indicates how rapidly the com-munity began to recover. A variety of herbaceous plants, different from those in the former forest, cover the ground.

  28. Pioneer stage, with fireweed dominant LE 53-24 Dryas stage 60 50 40 Soil nitrogen (g/m2) 30 20 10 0 Pioneer Dryas Spruce Alder Successional stage Spruce stage Nitrogen fixation by Dryas and alder increases the soil nitrogen content.

  29. IV. Biogeographic Factors on Community • Equatorial-Polar gradients • Area effects • Species-area curve (p. 1176) • Island equilibrium model • Size and distance from mainland • Immigration/extinction

  30. 180 160 140 LE 53-25 120 100 Tree species richness 80 60 40 20 0 700 900 1,100 100 500 300 Actual evapotranspiration (mm/yr) Trees 200 100 Vertebrate species richness (log scale) 50 10 500 2,000 1,500 1,000 Potential evapotranspiration (mm/yr) Vertebrates

  31. 1,000 LE 53-26 100 Number of species (log scale) 10 1 109 107 10 106 1 104 108 100 103 105 1010 Area (acres)

  32. LE 53-27 Immigration Immigration Immigration Extinction Extinction Extinction (small island) (near island) (large island) (far island) Extinction Immigration (far island) (large island) Extinction Immigration Rate of immigration or extinction Rate of immigration or extinction Rate of immigration or extinction (near island) (small island) Large island Equilibrium number Small island Near island Far island Number of species on island Number of species on island Number of species on island Effect of island size Effect of distance from mainland Immigration and extinction rates

  33. 400 LE 53-28 200 100 50 Number of plant species (log scale) 25 10 5 1 0.1 100 10 1,000 Area of island (mi2) (log scale)

  34. V. Views of Community Structure • Integrated hypothesis • Individualistic hypothesis

  35. Population densities of individual species LE 53-29 Environmental gradient (such as temperature or moisture) Integrated hypothesis Population densities of individual species Environmental gradient (such as temperature or moisture) Individualistic hypothesis Number of plants per hectare 600 400 200 0 Moisture gradient Wet Dry Trees in the Santa Catalina Mountains

More Related