Honors Biology notes – Ecosystems and populations
I. Biomes/the Biosphere (chapter 34)
A. Components of an ecosystem
1. physical
2. living
B. organisms have adaptations to the abiotic and biotic components of their
environment; this is explained by natural selection
C. climate effects local biomes
1. seasons (fig. 34.5)
2. temperature
3. moisture/precipitation
4. rain shadows (fig. 34.5F)
D. Aquatic biomes
1. oceans (fig. 34.6B)
2. estuaries
3. coral reefs
4. wetlands (swamp, marsh, bog, etc)
5. rivers
E. terrestrial biomes – overview fig. 34.8
1. tropical forests (some are rain forest)
2. temperature deciduous forest
3. boreal forest
4. savanna
5. temperate grasslands
6. tundra
7. desert
8. chaparral
9. biomes vary by latitude and also by altitude (moving up a
mountain is like moving north from the equator)
II. Population dynamics – chap 36
A. definition of population
B. measuring populations and their distribution (Fig 36.2)
C. population growth depends on birth and death rates
1. exponential growth produces a “J-shaped” curve (fig. 36.4A)
2. growth is eventually limited by resources, producing an “Sshaped” curve (fig. 36.4C)
3. the maximum sustainable number is the carrying capacity
4. growth can be limited by various factors (p. 730-731)
5. various cycles are typical of different populations (example lynx and hare - see also fig. 36.6)
6. survivorship curves (fig. 36.3) and various life history
“strategies” (fig. 36.7)
a. r-selected populations have “big-bang”
reproduction
b. K-selected populations are more stable

parental care is a characteristic - check out
these pictures of a hummingbird caring for
her eggs!
D. human population growth
1. history – fig. 36.9A
2. both numbers and consumption rates (ecological footprints – fig.
36.11B) contribute to environmental problems
3. population growth progresses through a demographic transition
(fig. 36.9B)
4. Age structure diagrams help compare different countries
population (fig. 36.9C)
E. when we use biological resources (fishing, farming, hunting) we need to
understand population growth in order to use them sustainably
III. Community and ecosystem ecology - chap 37
A. definition of community and ecosystem
B. relationships between species (examples and more info)
1. competition
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competitive exclusion (fig. 37.3A)
resource partitioning
2. predator-prey (p. 744-745)
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mimicry
camoflage
co-evolution
keystone species
3. symbiotic relationships
a. mutualism (Fig. 37.4)

match flowers with their pollinators
b. commensalism
c. parasitism - p. 745
4. keystone species (p. 749)
C. Disturbance and succession (Fig. 37.12)

Glacier Bay National Park has glaciers that have retreated dramatically in
the past 200 years (more on Glacier Bay)
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vegetation at Mt. St. Helens is growing back after the 1980 eruption
the role of fires
D. energy flow and food webs – fig. 37.16
1. 10% rule – fig. 37.17

Animal migrations are often linked to food availability check out the top 10 amazing animal journeys
2. bioaccumulation/biomagnification
E. chemical/nutrient cycles
1. water
2. carbon (fig. 37.19)
3. nitrogen (fig. 37.21)
4. phosphorus (fig 37.20)
4. human use can alter these cycles - p. 758-759
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burning fossil fuels released excess CO2 into the air
synthesis and application of fertilizers effects oxygen levels
in water
IV. Conservation Biology (chap 38)
A. preserving biodiversity
1. habitat loss, introduced species, and overexploitation are the
chief problems
2. reasons for preservation
3. distribution of diversity varies around the globe
4. Endangered Species Act and the role of habitat preservation
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habitat fragmentation is a concern
creating “edges” and corridors affects biodiversity
B. global climate change
1. natural greenhouse effect and increase in CO2
2. possible consequences
C. pollution – water and air