Transcript Document

Chapter 10
An Introduction
to Ecology
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Ecology
study the interaction
among organisms and
their environment.
distinct characters of
natural environment that
determine which
organisms live there.
Habitat
A group of individuals of the same species
that live together, mate with one another
and produce offspring
Population
Different populations of
organisms that live in the
same place.
Community
(assemblage)
Why assemblage ?
7
Physiological adaptation
-- a adaptation not pass to offspring
Natural selection
-- production of more offspring of the bestadapted individuals in a population
Evolutinary adaptation
-- acclimination
Figure 10.02a
Population growth types
Figure 10.02b
Exponental types
Figure 10.03
Population explosion
Figure 10.04
Logistic growth types
Figure 10.05
Limiting resources
Carrying capacity
16
Self regulation
-- growth rate
decreases as the
population increases;
limited by environment
or organisms
themselves
Competition
Interspecific competition and
intraspecific competition
competitive exclusive
competitive superior
18
Figure 10.06
Resource partitioning (character displacement)
Resource partitioning
share limited resource
coexist
generalization and specialization
20
-- the role of a species
plays in the community
Ecological niche
Figure 10.07
Predation
Predation
 Predator
 Prey
 Herbivory
 Carnivore.
23
The most successful predator
Catch more food
Survive longer
Grow faster
Produce more offsprings
Each generation will be a bit better in capture
its food
Trade-off between being bigger and grow
faster
24
Selection
Stabilizing selection: eliminate individuals far
from optimal balance
Dirctional selection: selection drive towards
new optimal balance, when the condition
changes (include physical and biological
factors)
25
Natural selection favor prey
-- More successful at getting away from predator
e.g. camouflage
Indirect interaction
-- one species interact with the 2nd one,
affect the third species
Trophic cascade
-- an effect on one species may flow
through an ecosystem
Inducible
defense
Defense mechanism that
are used only in response
to predator
--Both predator and prey
evolve
Coevolution
Pg. 213
Symbosis (live together)
Mutualism; facultative symbiosis
Cleaning association
obligate symbiosis
Commensalism
parasitism
Larval ecology
planktonic larvae depend on favorable
current to carry
them to the right place and right time
Figure 10.21
Major Marine Lifestyles and Environment
Figure 10.22
Depth difference
Figure 10.11
THE FLOW OF ENERGY AND MATERIALS
Trophic: nutrition
Figure 10.12
Autotrophic and heterotrophic
Consumers
Primary
producers
Figure 10.13
Trophic level
Food chain
Food web
-- 5-20%, average on 10%
Trophic efficiency
Figure 10.14a
Pryamid of energy
-- less energy
available at
each level
Figure 10.14b
Pryamid of number or biomass
-- Also fewer individual
organisms reach the
next level
-- Particulate organic matter (POM)
-- Detritus
-- Dissolved organic matter (DOM)
-- Nutrient regeneration
45
Figure 10.15
Primary production
Gross and net primary production
unit: mgC/m2
Figure 10.16
measurement
Primary productivity
• Amount of new organisms being produced/
unit time.
• unit: mgC/m2/yr
49
Rate depends on light and nutrients
50
Standing stock (crop)
Total amount (number) of
organism in the area.
Standing stock (crop)
the difference between standing stock and
productivity
-- high productivity and low standing stock
of phytoplankton in the open ocean
pyramid of biomass refers to the
productivity, not the standing stock
52
Standing stock of phytoplankton is
usually determined by the concentration
of chlorophyll
Chlorophyll
Chlorophyll concentration measurements
 fluorometer
 isotopes (14C)
54
Figure 10.17
Satellite imagine
Cycles of essential nutrients
 carbon cycle
 nitrogen cycle
 Phosphate cycle
56
Figure 10.18
Carbon cycle
-- major source:
atmosphere
-- photosynthesis,
respiration,
biogenic sediments
Figure 10.19
Nitrogen cycle
-- major sources: air,
land ( river, fertilizers,
sewage, other human
sources), fossil fuel
Nitrogen fixation
• cyanobacteria
• human activities produce more fixed
nitrogen than natural sources
• Artificial sources;
-- agricultural fertilizers: directly, human and
animal wastes
-- cultivation of nitrogen-fixing crop (e.g.
legume豆類植物).
-- fossil fuel burning.
59
Denitrification
• Processes: [NO3-1] [NO2-1] [N2O-1] [NO]
[N2]gas
• Until recent times, natural nitrogen fixation
was balanced by the denitrification; keep
global environment more or less constant
• More fixed nitrogen is building up with
potentially catastrophic consequences
60
Figure 10.20
Phosphate cycle
-- Major sources: river
(rock weathering,
fertilizers, other
human sources,
major), air (minor)
-- One-way flow system
-- Chemical precipitation
-- Recycle by uplift of
marine sediment on land