ap biology an introduction to ecology the distribution and adaptations of organisms
TRANSCRIPT
AP Biology
An Introduction to Ecology
The Distribution and Adaptations of Organisms
Introduction to Ecology Ecology is the study of organisms and
their interactions with their environment. The environment includes 2 types of
factors: Biotic factors – the living parts of the
environment Plants, animals, bacteria, fungi, protists
Abiotic factors – the nonliving parts of the environment Water, oxygen, light, temperature, etc.
Levels of Organization
Levels of increasing complexity: Population –
A group of organisms of the same species that live together in a certain area
Community – A group of organisms of different species that
live together in a certain area Ecosystem –
All the living and nonliving things in a certain area
Biome – a group of ecosystems that have similar climates and communities
Biosphere – the entire portion of the planet that supports life
The Importance of Abiotic Factors Not every organism can live everywhere on
Earth Abiotic factors determine which organisms can
survive where: Temperature – effect on body temperature Water – too much/not enough water Light – availability for photosynthetic organisms Wind – amplifies effects of temperature Rocks/Soil – which organisms can live with/on
them, based on pH and mineral composition Periodic Disturbances – catastrophes, such as
tornadoes, fires, tsunamis, etc.
Homeostasis Organisms must maintain homeostasis, a steady-state
internal environment, despite changes in the external environment
Organisms respond to abiotic factors in one of two ways:
1. Regulators (endotherms) maintain a nearly constant internal environment, despite external conditions (Cold-blooded)
2. Conformers (ectotherms) allow their internal environment to vary (Warm-blooded)
- live in environments which remain relatively stable
The Principle of Allocation This principle states:
Each organism has a limited amount of energy that can be spent on obtaining food, escaping from predators, coping with environmental fluctuations (maintaining homeostasis), growth, and reproduction
Adapting to Changing Conditions Organisms can respond to their changing
environments using 3 different types of responses:
1. Physiological Responses
- changing the functioning of the body
- acclimation
- athletes in Torino, moving to Denver...
2. Morphological Responses
- changing the anatomy (structure) of the body
- example: dogs growing thicker fur
Adapting to Changing Conditions3. Behavioral Responses
- changing behavior to adapt to the change
- moving to a more favorable location
- cooperative behavior (huddling, etc.)
Biomes Aquatic Terrestrial (Our focus will be on these!)
Tundra Taiga Tropical Forest Savanna Chaparral Desert Temperate Grassland Temperate Deciduous Forest
Tundra Arctic = 20-60 cm/yr. Alpine (mountains) = may exceed 100 cm Average winter temp. -30 degrees C Summer < 10 degrees C Long winter; short summer Herbaceous (low) plants, a few DWARF shrubs Musk oxen, caribou, reindeer, bears, wolves,
various birds High latitudes or highest elevations (even at
equator!)
Taiga (Northern Coniferous Forest) 30-70 cm ; some much more Winters -50 degrees C in winter Summer 20 degrees C Long winter; short summer may be hot Plants: cone-bearing trees, diverse
shrubs, herbs Animals: Birds, moose, bears, Siberian
tigers; insects Northern N. Am. and Eurasia to edge of
tundra
Tropical Forest T. Rainforest: 200 - 400 cm/yr T. Dry forest 150 – 200 cm/yr 25-29 degrees year round (Warm!) Summer year round Plants: diverse; 4 or more layers Animals: diverse: 5-30 million species
yet to be discovered! Equatorial regions
Savanna Seasonal rainfall; 30-50 cm/yr with long
drought season Temperature: 24-29 degrees C (warm!); more
variation that Tropical forests Dry season lasts 8-9 months Plants: Scattered trees; thorny; small leaves
(why?)Grasses; Must be fire & drought tolerant Animals: Herbivorous mammals; insects;
grazers Equatorial & subequatorial regions
Chaparral Seasonal ppt.; Rainy winter; Long dry
summer (30-50 cm) Cool fall, winter, & spring (10-12 degrees C) Summer can reach 30-40 degrees C Plants: shrubs, small trees, grasses; adapted
to drought; some have seeds that germinate after fire.
Animals: mammals (browsers) amphibians, reptiles, insects
Mid latitude coasts
Desert < 30 cm / yr (arid/dry) Hot deserts > 50 degrees C Cold deserts (Antarctica) <-30 degrees C Temps vary seasonally and daily (colder at
night) Plants: Cacti, shrubs w/ deep roots
(why?); small leaf surface area (why?) Animals: lizards, scorpions; birds;
insects; many nocturnal animals (why?)
Temperate Grassland
Dry winters; wet summers;
30-100 cm/yr.; seasonal drought Cold winters < -10 degrees C; Hot
summers 30 degrees C Plants: Grasses Animals: Large grazers; burrowing
mammals Plains & prairies around the world
Temperate Deciduous Forest 70-100 cm/yr Cold Winters 0 degrees; Hot summers 35
degrees C; 4 distinct seasons Plants: Trees, shrubs, herbaceous layer;
(broadleaved, deciduous plants) Animals: variety of mammals, birds,
insects Midlatitudes Our biome!