Adaptations & the Physical Environment

Kangaroo rat

FIELD BIOLOGY & METHODOLOGYFall 2015 Althoff

Lecture

03

Tolerance Limits

• Limiting factors vs. zone of tolerance (~ concentration gradient???)

• Zones (handout): a) optimum range b) zone of physiological stress c) zone of intolerance

Gradient HIGHLOW

Popn a

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Pulsa

tions

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ute

Temperature 0C

Halifax individuals

Tortugasindividuals

_____ species of Jellyfish (Aurelia aurita) but from different populations (genetic variation increasing adaptability to local environment!!!).

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”

Adaptations

Modifications which better suit the organism to its particular environment

Gray wolf: colder climate

African hunting dog: warmer climate

vs.

Notice: _______________________

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”

Specific examples• Salt and water balance

• Nitrogen excretion

• Temperature & water conservation

• Plant-water relationships

• C3, C4, & CAM Photosynthesis

Fish: ______________________ actively exclude or retain solutes to maintain salt balance

Highly developed __________ in kidneys…. allows for maximum retention of H20 during urine formation

Urine almost comes out paste-like. Animal almost exclusively gets all of its water from seeds (i.e., metabolizes H20)

Kangaroo rat: found in dry, arid or semi-arid environments

C3 (cool season plants)

• Plants well-adapted to “average” temperature and “average” moisture conditions… think ________________

• Relates to C-assimiliation

• Examples: Kentucky bluegrass, maples, dandelion

C4 (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

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

Back to “environmental conditions”

Most organisms have “optimum range.” Within that concept, there are eurytypic and stenotypic organisms

Range of Tolerances

• _________________ -- species with wide tolerance ranges

ex:white-tailed deer & “any” habitatcombination

• _________________ -- species with narrow tolerance rangesex: Kirtland’s warbler & jack pine

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

Topographic and Geologic Influences

The “lay” of the land influences the local environment. Soil and exposure have profound influences on ___________ and therefore __________ distribution

Lay of the land….

Tbasic soil types Ricklefs Table 4.2, p90

Local Variations

• RIPARIAN—forested zones along rivers, creeks, and streams

• XERIC—dry sites

• MESIC—”in between” sites

• HYDRIC—wet sites

Life Zones

• Distinct “_______” of vegetation. Belts are a result of local climate which influences vegetation…

…which influences animal diversity and distribution

Fig 4.20 p89

Life Zones

Lower Sonoran zone: saguaro cactus, mesquite, herbs

Upper Sonoran zone: agave and grasses

Transition zone: ponderosa pine

Alpine zone: higher up, bushes, herbs, lichens

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

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…C3 pathway, C4 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