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Adaptations & the Physical Environment Kangaroo rat FIELD BIOLOGY & METHODOLOGY Fall 2015 Althoff Lecture 03
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Tolerance Limits Limiting factors vs. zone of tolerance (~ concentration gradient???) Zones (handout): a) optimum range b) zone of physiological stress c) zone of intolerance
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Gradient HIGH LOW Pop n abundance
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Pulsations/minute Temperature 0 C Halifax individuals Tortugas individuals _____ species of Jellyfish (Aurelia aurita) but from different populations (genetic variation increasing adaptability to local environment!!!).
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Tolerance Limits…con’t Simplistic view: one factor “acting” at-a-time Reality: _________________ of factors ________ factor: “one factor…more than any other…determines distribution & abundance”
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Adaptations Modifications which better suit the organism to its particular environment Gray wolf: colder climate African hunting dog: warmer climate vs. Notice: _______________________
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Adaptations…con’t May allow control “ flux ” of heat or various substances across their surfaces By regulating __________ with physical environment, internal environment can be controlled better. “Can move or adjust”
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Specific examples Salt and water balance Nitrogen excretion Temperature & water conservation Plant-water relationships C 3, C 4, & CAM Photosynthesis
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Fish: ______________________ actively exclude or retain solutes tomaintain salt balance
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Highly developed __________ in kidneys…. allows for maximum retention of H 2 0 during urine formation Urine almost comes out paste-like. Animal almost exclusively gets all of its water from seeds (i.e., metabolizes H 2 0) Kangaroo rat: found in dry, arid or semi-arid environments
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C 3 (cool season plants) Plants well-adapted to “average” temperature and “average” moisture conditions … think ________________ Relates to C-assimiliation Examples: Kentucky bluegrass, maples, dandelion
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C 4 (warm season plants) Plants well-adapted to hot temperature and “average” moisture conditions …. think _______________ Relates to C-assimilation Examples: big bluestem, switchgrass, tomatoes, corn, sunflower
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CAM Plants well-adapted to hot temperature and “dry” moisture conditions (i.e., arid conditions) Carbon assimiliation daytime, Calvin cycle nighttime Examples: cacti & prickly pear
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Back to “environmental conditions” Most organisms have “optimum range.” Within that concept, there are eurytypic and stenotypic organisms
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Range of Tolerances _________________ -- species with wide tolerance ranges ex:white-tailed deer & “any” habitat combination _________________ -- species with narrow tolerance ranges ex: Kirtland’s warbler & jack pine
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Seasonal Cycles – Temperate Lakes Understand the temperature profile of a typical lake related to seasonal changes (Fig. 4.13, p82) ____________—zone of rapid change. Marks boundary between epilimnion (warm) and hypolimnion (cold) waters
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Topographic and Geologic Influences The “lay” of the land influences the local environment. Soil and exposure have profound influences on ___________ and therefore __________ distribution
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Lay of the land….
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Tbasic soil types Ricklefs Table 4.2, p90
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Local Variations RIPARIAN—forested zones along rivers, creeks, and streams XERIC—dry sites MESIC—”in between” sites HYDRIC—wet sites
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Life Zones Distinct “_______” of vegetation. Belts are a result of local climate which influences vegetation… …which influences animal diversity and distribution
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Fig 4.20 p89 Life Zones
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Lower Sonoran zone: saguaro cactus, mesquite, herbs
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Upper Sonoran zone: agave and grasses
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Transition zone: ponderosa pine
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Alpine zone: higher up, bushes, herbs, lichens
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Landscape Ecology Study of the __________ nature of the environment influences the functioning of the ecosystem Emphasis on movement between habitats by organisms Human influence on landscape is tremendous
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In summary… Mechanisms by which organisms interact with their physical environment help us understand why organisms are specialized to ______________ _________________ Plant species ___________(C) in one of three ways: C…C 3 pathway, C 4 pathway, or CAM pathway. Each way is specialized to provide a competitive advantage under certain sets of climatic conditions ____________ represent result from climatic influences on plants, which in turn have influences on the distribution of animals
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