1 / 42

Lecture 6

Lecture 6. Principles of Ecology: Ecosystem function and landscape ecology. Lecture 6 topics. Ecosystem function Producers, consumers and decomposers Nutrient cycling Carbon cycling and C sequestration Landscape ecology Importance of riparian areas. Ecosystem function.

laszlo
Download Presentation

Lecture 6

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. Lecture 6 Principles of Ecology: Ecosystem function and landscape ecology

  2. Lecture 6 topics • Ecosystem function • Producers, consumers and decomposers • Nutrient cycling • Carbon cycling and C sequestration • Landscape ecology • Importance of riparian areas

  3. Ecosystem function • Most important functions are energy and nutrient cycling 3

  4. Energy CO2 O2 Water Sugar 4

  5. CO2 O2 Sugar Water Energy 5

  6. 6

  7. Organisms in an ecosystem may be identified by how they obtain their food. 7 (Miller 2002)

  8. Pyramid of Energy Flow 8 (Miller 2002)

  9. 2. Producers, consumers and decomposers • Fluxes of nutrients and carbon are controlled by producers, consumers and decomposers as well as by the hydrologic cycle. 9

  10. 10

  11. Cycle of Matter and Energy between the main Structural Components of an Ecosystem (Miller 2002) 11

  12. 3. Nutrient cycling • Most important nutrients are: • N • P • Ca • Other cations (K, Mg) • S 12

  13. 13

  14. 14

  15. 15

  16. Another N cycle 16

  17. P cycle 17

  18. 18

  19. 4. Carbon cycling and carbon sequestration • Carbon inputs to ecosystems are largely through photosynthesis. Carbon outputs are through respiration, dissolved organic and inorganic carbon and removal of forest products. Carbon sequestration occurs when inputs exceed losses. How effective are forests at sequestering Carbon? 19

  20. 20

  21. 21

  22. 5. Landscape ecology • Landscape ecology addresses how spatial variation (heterogeneity) in the landscape affects ecological processes such as the distribution and flow of energy, materials and individuals in the environment. It includes the study of the landscape pattern It stresses the role of human impacts on landscape structures and functions and proposes ways for restoring degraded landscapes. It explicitly includes humans as entities that cause functional changes on the landscape 22

  23. Satellite data, aerial photos and GIS are tools of landscape ecology 23

  24. 24

  25. GIS an important tool 25

  26. Patch and mosaic Patch - relatively homogeneous area that differs from its surroundings. Have definite shapes and configurations. Patch dynamics - Patches change and fluctuate. Matrix - “background ecological system” of a landscape with a high degree of connectivity. Connectivity - measure of how connected or spatially continuous a corridor, or matrix is. e,g,, a forested landscape (the matrix) with fewergaps in forest cover (open patches) will have higher connectivity. Corridors have important functions as strips of a particular type of landscape differing from adjacent land on both sides. Connect habitats. Network - interconnected system of corridors Mosaic - describes the pattern of patches, corridors and matrix that form a landscape in its entirety. 26

  27. U.S. Forest Service/BLM landscapes • The Northwest Forest Plan in 1994 divided the federal forest landscape in each National Forest and BLMs land into: • Matrix – timber harvesting allowed • Old-growth reserves • Riparian reserves • Adaptive management areas 27

  28. Boundary and edge Boundary - The zone composed of the edges of adjacent ecosystems Edge - portion of an ecosystem near its perimeter. Edge effect - distinctive species composition or abundance in the outer part of the landscape patch. 28

  29. Ecotones A type of boundary is the ecotone, or the transitional zone between two communities. Ecotones – lakeshore or riparian zone, or human-created (cleared agricultural field and a forest). The ecotonal community retains characteristics of each bordering community and often contains species not found in the adjacent communities. Species richness may be higher or lower than either side of the ecotone. 29

  30. Wildlife corridors, riparian areas, ecotones, edges, and connectivity are all illustrated here 30

  31. Forest edges in Washington 31

  32. Disturbance and fragmentation Disturbance - alters the pattern of variation in the structure or function of a system, Fragmentation - breaking up of a habitat, ecosystem, or land-use type into smaller parcels. Disturbance is generally considered a natural process. Fragmentation causes land transformation, an important current process in landscapes as more and more development occurs. 32

  33. Landscape ecology is important in the understanding of: Fire Insect outbreaks (defoliators, bark beetles) Global change (temperature, moisture, snow pack changes) Urbanization Other big scale things 33

  34. Fires 34

  35. What caused this? 35

  36. Landscape temperature 36

  37. 6. Riparian areas Type F Jeff Grizzel, WA DNR 37

  38. Importance of riparian areas • Ecotone between stream and lake ecosystems and upland forest ecosystems. Buffer natural and human caused disturbances. • High biodiversity • Species are different than upland. More hardwoods because of high frequency of disturbance. Should we replace red alder with conifers because they provide longer lasting LWD. • Moderate stream temperatures through shading; important for fish • Modify nutrients coming from uplands and marine environments (marine derived nutrients) 38

  39. 39

  40. Alder versus conifers in riparian areas ONP: 3 sites Snider Twin West Twin DNR: 3 sites Alder Canyon Lindner 40

  41. 0.24 0.20 0.16 0.12 0.08 0.04 0.00 0 5 10 15 20 NO3-N in alder and conifer streams R2=0.90 [NO3-N], mg • L-1 % red alder in watershed 41

  42. Sample type Biomass Quality N P Vegetation 5x 3x 4x Surface/well chemistry Seston =, var* Algae sp, fall* = Drifting/emerging invert late summer* ? ? Fish ? ? ? *Some seasonal or flow dependence Alder sites as compared to conifer sites 42

More Related