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Ecology

Mammalogy (Fall 2013 Althoff - reference FDVM Chapters 23-25). LEC 13. Ecology. INFLUENCE OF UNGULATES ON ECOSYSTEMS. Natural “Disturbances”. Fire Volcanic action Flooding Drought Disease _____________________________. Human Induced (non-wildlife management).

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Ecology

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  1. Mammalogy (Fall 2013 Althoff - reference FDVM Chapters 23-25) LEC 13 Ecology

  2. INFLUENCE OF UNGULATES ON ECOSYSTEMS

  3. Natural “Disturbances” • Fire • Volcanic action • Flooding • Drought • Disease • _____________________________

  4. Human Induced(non-wildlife management) • Fire (pre-historic & historic) • Fire suppression • Logging (forest) • Grazing (rangelands) • Cultivation/agriculture (farmland) • Development (all lands)

  5. Consequences of disturbances… • _______________ loss of habitat • _______________ of habitat • Succession _____________

  6. INFLUENCE OF UNGULATES ON ECOSYSTEMS Hobbs, N. T. 1996. Modification of ecosystems by ungulates. Journal of Wildlife Management 60:695-713.

  7. Overview... • Traditionally look at ungulate populations as __________of plant communities • Now...evidence for ungulates having influence on changes in organisms ________________________

  8. Evidence that...“...ungulates are not merely outputs of ecosystems, they may also serve as important ___________ of ecosystem processes at several scales of time and space”Hobbs (1996:695)

  9. Focused on... • _____________ of nutrient cycles • Influence on _________________ production • Modification of __________ disturbance-- particularly fire regimes

  10. Scales come into consideration by the ... • Choice ungulates make at the “________________” level • Choice ungulates make at the “____________” level • Choice ungulates make at the “_________” level

  11. Presented in perspective to... • Soil development • Plant/herbivore coevolution • Climate & weather

  12. NUTRIENT CYCLING • _____________ availability affects primary production & composition of plant community

  13. 1 ) accelerate nutrient turnover __________ by excreting nutrients in a form readily taken up by microbes & plants Two influences by ungulates: 2) _____________ modifying the quantity and quality of plant litter available for decomposition

  14. Nitrogen (N) Returns in Dung & Urine • Dung & urine contain high levels of soluble ammonium and urea • Plants showing evolutionary history of grazing show elevated growth responses to urea

  15. Nitrogenous Waste Products • NITROGENOUS WASTES = breakdown of various molecules, including nucleic acids and amino acids • AMINO ACIDS NOT used for protein synthesis are broken down by the body to generate energy or converted to fats or carbs that can be stored… • …this requires amino groups (-NH2) be removed excreted as ammonia, urea, or uric acid

  16. PROTEINS Nitrogenous Wastes amino acids -NH2 ammonia urea uric acid Need water to excrete Need energy to produce

  17. Nitrogenous waste habitat animals toxicity highest water • Ammonia • Urea • Uric acid aquatic invertebrates. bony fishes amphibian larvae adult amphibians mammals land 2nd highest lowest land insects birds reptiles

  18. Excretion.... • Promotes decomposition of organic matter and release of mineral N __________ than normal decompositon in litter • Higher nitrogen excretion influenced by ________________ intake of N

  19. UNGULATE URINE Dyanmics of nitrogen excretion by ungulates: size of animal and dietary Ninfluence amount of excreted nitrogen

  20. Excretion...con’t • Does not take place uniformly across an animal’s home range...thus, concentrations at certain ___________ __________ can be very significant

  21. Landscape level:elk & bison in Yellowstone excreted at 0.81-4.60g N m-2 yr-1 ...about _________ greater than amount of N in senescent plants and almost 1/3 of the total N mineralized

  22. Patch level:deposition of sheep dung doubles the levels of soil ______________Plant level:additions of N can be as high as 50-100g m-2 yr-1

  23. Distribution not uniform... • ______ migrate...movement of N from summer to winter ranges • _________ ungulates seek shade under trees & excrete there • _________ rests on level ground... excrete there • ________ feed selectively on patches fertilized previously with urine

  24. EFFECT ON PRIMARY PRODUCTIVITY • Consumption of plants by native ungulates ____________ annual net primary production as a result of “grazing-induced feedbacks” among plants, plant communities, and soil environments....

  25. known as GRAZING OPTIMIZATION HYPOTHESIS... ...predicts that plants can compensatefor effects of defoliation such that ________ plant communities produce more biomass than ______________ zones.

  26. Review handout ....MECHANISMS CONTRIBUTING TO COMPENSATORY GROWTH FOLLOWING DEFOLIATION

  27. Wild vs. Domestic • Domestic--usually _____________ by fencing...thus, may mask these responses • Domestic--because of fences, _____________ usually higher __________term

  28. “Grazing Lawns” • Heavy grazing/browsing of patches ...where repeat grazing/browsing will (does) occur • Plants are maintained in juvenile, _______________ state

  29. Grazing lawns...con’t • where regrowth of plants is slow or absent there is “_____________” feedback • where regrowth is rapid, feedback is “_____________” • RESULT: landscape _______________

  30. EFFECT ON FIRE REGIMES • Grazing & browsing by ungulates modifies TYPES and AMOUNTS of vegetation available to burn • Ungulates, therefore, exert some control over __________ and ________________ dynamics of fire

  31. Influences on fire... • With grazing, standing crop of biomass is reduced...and it results in changes of: a) ___________ b) ___________ c) ___________ ….of fires.

  32. Influence on fire...con’t • Another alternative status is evident: a) Fire _______ areas (not heavily grazed) b) Fire __________ areas (heavily grazed)

  33. Fire can result in.... • Greater intensity of fire in ungrazed patches...influencing quicker nutrient recycling, which can “________” the patch. • This, in turn, acts as “homogenizing” effect selective grazing burning, Varying intensity

  34. Summary point: Diets, patches, and habitat selection play fundamental roles in determining the ways ________________ interact with their environment. The result is usually significant impact on the landscape, patch, and plant levels.

  35. MAMMALSDO INFLUENCE VERY SIGNIFICANTLY PLANT COMMUNITIES AND THEREFORE INFLUENCE ECOSYSTEMS

  36. Emerging field of study which is exploring “________________” and “________________” as it relates to populations (and metapopulations) is known as....LANDSCAPE ECOLOGY

  37. LANDSCAPE ECOLOGY

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