1 / 45

Human Resource Use

Human Resource Use. Human Values & Attitudes (Socio-political). Human Land Use Practices Agriculture Suburban Development Let’s pick on Indiana: 97% of land in state = privately-owned In central Indiana, 70+% of land in row crop <10% in forest Urban sprawl intensifying.

alec
Download Presentation

Human Resource Use

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. Human Resource Use Human Values & Attitudes (Socio-political)

  2. Human Land Use Practices • Agriculture • Suburban Development • Let’s pick on Indiana: • 97% of land in state = privately-owned • In central Indiana, • 70+% of land in row crop • <10% in forest • Urban sprawl intensifying

  3. Human Impacts • Ecosystem simplification: elimination of species from food webs via human alterations to land • Example: vertebrate communities in ag. landscapes

  4. Intensive Agriculture & Clean Farming

  5. Timber Extraction & Fragmentation

  6. Formation of Terrestrial “Islands”

  7. Oceanic Island = Terrestrial Island ?????

  8. Species-Area Relationship • S = cAz • S = # of species • A = island area • Positive correlation between island size & number of species • Applies to terrestrial “islands” also

  9. Island Biogeography • equilibrium model suggesting that the number of species occurring on an island represents a balance between immigration (in) and extinction (out) • Robert MacArthur & E.O. Wilson

  10. Habitat Fragmentation • Process of breaking contiguous unit into smaller pieces; area & distance components • Leads to: • < remnant patch size • > edge:interior ratios • > patch isolation • < connectivity • Community & Ecosystem processes altered

  11. Formation of Terrestrial “Islands”

  12. Patch size #patches Patch isolation Edge

  13. What about aquatic systems?

  14. What about aquatic systems? Con.Bio 12(6)

  15. Increased Edge Habitat

  16. Increased Edge Habitat

  17. Habitat Fragmentation • First-Order Effects: fragmentation leads to change in a species’ abundance and/or distribution • Higher-Order Effects: fragmentation indirectly leads to change in a species abundance and/or distribution via altered species interactions

  18. Habitat Fragmentation • area-sensitive species: species that require minimum patch size for daily life requirements • Edge effects: influence of factors from outside of a patch

  19. Edge Effects • Habitat surrounding a patch can: • change abiotic conditions; e.g., temp. • change biotic interactions, e.g., predation • Example of nest predation = edge effect of approximately 50 m into forest patch • But can extend 100’s of meters….maybe km’s

  20. Edge Effects • How does patch size (in a landscape) & shape affect amount of edge? • Groups – give me a mathematical example with forested landscapes that have timber extraction via clearcutting

  21. Exponential vs. Logistic No DD DD All populations same All populations same No Spatial component

  22. Incorporating Space • Metapopulation: a population of subpopulations linked by dispersal of organisms • subpopulations separated by unsuitable habitat • subpopulations differ in population size & distance between

  23. Metapopulation Model p = habitat patch (subpopulation) c = colonization e = extinction

  24. Another Population Model • Source-sink Dynamics: grouping of multiple subpopulations, some are sinks & some are sources • Source Population = births > deaths = net exporter • Sink Population = births < deaths

  25. <1 >1 <1 Source-sink Dynamics

  26. Source-sink Dynamics

  27. Corridors

  28. Who Cares? • Why bother discussing these models? • Metapopulations & Source-sink Populatons highlight the importance of: • habitat & landscape fragmentation • connectivity between isolated populations • genetic diversity

  29. Vancouver Island marmot(Marmota vancouverensis) ~100 left Isolated from hoary and Olympic marmots

  30. Vancouver Island marmot(Marmota vancouverensis) Natural tree succession

  31. Vancouver Island marmot(Marmota vancouverensis) • Logging – disjunct patches • - max. dispersal = 7 km • Climate • Prey-Predator Dynamics

  32. Differential Sensitivities to Habitat Alteration • Niche breadth (diet & habitat) – inverse relation • Range periphery = more sensitive (W & N) • Body size = mobility (allometric relation) • Social and territorial behavior (limited K) Swihart et al. 2003

  33. Ways to Manage 1) Featured Species Mgt • single species • particular purpose • e.g., white-tailed deer • could also include “umbrella species” and “flagship species” or “sensitive species”

  34. Ways to Manage 2) Species Richness Mgt • maintain diversity and certain # of each species (follow MVP concept) 3) Indicator Species Mgt • use a species (or group of species) to monitor environmental conditions • not necessarily managing for these spp. • bioindicators, biosentinels, “canary in coal mine”

  35. Ways to Manage 4) Guild Mgt or Life-Form Mgt • grouping of species based on use of same type of resources (e.g., foraging guilds)

More Related