ES 100: Environmental Ecology
Instructor: Sarah Teck
ES 100: Environmental Ecology
Instructor: Sarah Teck
A study of principles of ecology and their implications for analyzing environmental problems. Focus on understanding the processes controlling the dynamics of populations, communities and ecosystems. Specific examples emphasize the application of these concepts to the management of natural resources.
Lectures: Mon, Tues, Wed, Thurs 9:30‐10:40 am Office Hours: Mon and Tues 11‐12 pm or by appointment Office Location: 1304B Marine Science Research Building
Ecology
• The scientific
study of the
distribution and
abundance of
organisms, and
the interactions
that determine
distribution and
abundance
•
Ernst Haeckel
1886
• Oekologie
–Oikos: Greek (οἶκος) for “house or family”
–Logia: Greek (-λογία) for “the study of”
Ecology
• Applied science: knowledge that is practical for
benefiting humankind (agriculture, fisheries, disease)
– Ex: Processes responsible for determining the
distribution and abundance of mosquitoes in
highland Kenya. Benefit: helps us avoid/control
malaria
•
Pure (basic) science: knowledge for knowledge’s
sake. May not appear directly useful to us
– Ex: Processes responsible for determining the
structure and composition of shrublands and
wetlands in South Africa.
»
Note: Pure science sometimes ends up
being very valuable to humans
Ecology and Environmentalism
• Ecology is a science
– Understanding is achieved
through unbiased scientific
methods
– This understanding can help
predict, manage, and control
ecological problems
• Environmentalism is a
social concern
– Understanding and
advocacy are not always
independent
– Advocacy can help
manage, and control
ecological problems
Environmental ecology?
• Environmental science is the study of the
environment and solutions to threats facing the
environment
– it may focus on social science aspects (human
perceptions and policies)
– or it may focus on engineering, chemistry,
geology, atmospheric science, geography, physics,
biology, biogeochemistry…
– or ecology!
Tertullian 160‐~220 AD
• ‘We are burdensome to the world, the resources are scarcely adequate for us…. Already nature does not sustain us.’
• father of Latin Christianity and founder of Western theology.
• we are not the first generation to change the planet
More recent history
• Mid‐1800’s Romantic‐transcendental conservation ethic (aka Preservationist ethic) – 1903 John Muir with Theodore Roosevelt
– National Parks established
– ‘Everybody needs beauty as well as bread, places to play in and pray in, where nature may heal and give strength to body and soul alike.’
• Early 1900’s Resource conservation ethic
– Gifford Pinchot
– First chief of the Forest service
– ‘The greatest good for the greatest number for the longest time’ Alfred Lotka and Vito Volterra
• 1920’s theoretical ecology
Charles Elton
• 1920’s
• Population, community
ecology, invasive
species
• First to conduct field
study of small rodent
populations (1926)
Aldo Leopold
• 1930’s Wildlife, wilderness management
• Evolutionary‐Ecologic land ethic
“that land is a community is the basic concept of ecology, but that land is to be loved and respected is an extension of ethics”
• “first rule of intelligent tinkering is to save all the pieces.”
• “A thing is right when it tends to preserve the integrity, stability, and beauty of the biotic community. It is wrong when it tends otherwise.”
• Man is part of complex ecology
Course goals
• Understand why you see some of the things you see outside
• Appreciate that ecological phenomena occur on a variety of
spatial, temporal and biological scales, and how observed patterns
may be evident only at particular scales
• Recognize how ecological patterns can be obtained by means of
observations, field and laboratory experiments, and
mathematical and conceptual models
• Understand how ecology relies on true scientific evidence and
statistical rigor
The Basics
• Course Website –
gauchospace.ucsb.edu
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Syllabus
Lectures
Blog
Additional readings
• Two copies on reserve
• Textbook=great set of notes for the course!
Ecological World View (Essay 1.3 p 16)
1. You cannot alter just one component of an
ecological system
– Interconnectedness between human and natural systems
2. Human actions can have long-lasting ecological
impacts
– Policy and economic time horizons vs natural systems
3. We can learn from history
– Avoid repeating mistakes and learn from scientific studies
4. Conservation is essential
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Species and habitat conservation
5. Evolution continues
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Speed of evolution depends on the species’ generation time
(ex.bacteria become resistant to antibiotics quickly!)
Complex interactions in ecosystems
(human-natural system) ex: Lyme disease
spirochetes bacteria
transmitted by ticks
And to add more complexity…
Negative interactions = dashed line
Pos interactions = solid line
(mast=seeds and berries)
West Nile virus
Ecological phenomena occur at a variety of scales
• Biological
• Spatial
• Temporal
Levels of biological organization in ecology
The appropriate scale of a study depends on research question
– Individuals
» How do environmental conditions influence the growth rates of individual
grass rockfish, Sebastes rastrelliger?
– Populations
» How does the abundance of grass rockfish vary over time?
– Communities
» How does kelp forest community structure change following the closure of
fisheries for grass rockfish?
– Ecosystems
» How is the recruitment of juvenile grass rockfish to a kelp forest influenced
by oceanographic changes associated with El Nino Southern Oscillation?
– Landscapes/Seascapes and Biosphere
» How is will climate change influence the distribution of commercially
important fish species?
Appropriate Spatial and Temporal Scales
– Spatial Scale
• Are populations of grass rockfish open or closed
(how connected are populations)?
• How will abundance be surveyed?
• How many areas can we afford to survey?
– Temporal Scale
• What time of the year do juveniles recruit to the
population?
• Is mortality constant from year to year?
• Do individuals aggregate to breed during certain times
of the year?
How are ecological patterns studied?
•Ecological evidence comes from a variety of different sources
– Observations: watch and describe things as they occur naturally.
– Experiments: control (hold constant) certain factors and strategically vary
other factors, then observe and describe how things respond.
– Mathematical models: use data and equations to approximate the real world,
then conduct experiments within the model.
The scientific method
• Start with a research question
– Ex: Why are grass rockfish larger in northern
regions of this species’ range?
• Form a hypothesis
– Ex: Grass rockfish growth is limited in certain
areas by low food availability
• Make predictions
– Ex: Areas with high food will have larger
individuals and vice versa
Refine the question and hypotheses
• Refine the question
– Ex: How do temperature and
food availability interact to
influence the growth of grass
rockfish?
• New hypotheses (& predictions)
Ex:
– Growth rates are maximized when
temperatures are high and lots of
food is available
– Scope for growth is maximized
when lots of food is available,
regardless of temperature
Hypothesis Testing
• Experimental design, data
collection, analysis, compare
predictions and data
• Ex:
• Tag a bunch of fish and
record rates of growth
• Measure environmental
conditions such as
temperature and food
availability
• hypothesis testing (confirm or
reject hypotheses)
Ecological Evidence
• Draw conclusions from
your results
• Eventually (i.e., with
enough evidence), form
theory: a framework of
concepts that explains
phenomena
• Form new hypotheses,
questions and additional
tests
Testing new hypotheses
Wait a second, shouldn’t we expect
increased growth rates where the water is
warmer?
• Increased temperature = increased rate
of physiological processes
• Our observational approach relies on
correlations between growth and
multiple environmental conditions
(temperature and food availability)
 This cannot provide a mechanism
because…
…correlation does not necessarily mean
causation
Correlation does not necessarily mean causation
Using experimentation to test new hypotheses
• How do temperature and
food availability interact to
influence the growth of
grass rockfish?
– Experimentation
• Actively manipulate
variables (temperature
and food availability)
• Tease apart specific
mechanisms
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The real world is simplified into a number of key attributes
– Reductionism: the principle of analyzing complex things into simpler constituents; and a doctrine that a complex system, theory, or phenomenon can be fully understood in terms of simpler concepts or in terms of isolated components (New Shorter Oxford English Dictionary 1993)
Observation
Action:
Strengths:
Experimentation
•See patterns in the real •Manipulate systems on a world
manageable scale
•Grounded in reality
•Variables of interest can be controlled to infer mechanism (reductionist)
• Not realistic on larger •Mechanistically weak Weaknesses:
scales
because conclusions are • Ignores emergent based on correlations
properties
(Emergent properties are novel properties that arise from the combination of simpler constituents)
A Bit On the Value of Math in Ecology
• Even the simplest ecological systems can quickly become very complex
– Temperature and/or food availability may interact with other independent variables such as species interactions & foraging behavior • Many interacting variables may be efficiently summarized by mathematical models, constructed and manipulated according to the investigator’s design (more on this as we move along…)
• “Essentially, all models are wrong, but some are useful”
‐‐George E.P. Box, 1987 (statistician)
• "nature is a structure of evolving processes. The reality is the process.” Like all scientists, ecologists must “seek simplicity, but distrust it” ‐‐A.N. Whitehead, 1953 (philosopher and mathematician)
Models approximate the real world
Evidence and scientific rigor
• Ecology relies on true scientific methods and the application of rigorous statistics
– Conclusions based on standardized statistical analyses
– Confidence in the conclusions is presented for all to see
Statistics and Scientific Rigor
P‐value = probability of getting your result from random (or chance alone)
Low p‐values allow you to reject the null hypothesis and accept your hypothesis
P = 0.5
P = 0.001
Null Hypothesis
P = 0.1
P = 0.04
Case Study: Succession on Old Fields in Minnesota
• Ecological Succession: Predictable and orderly changes in time in the composition or structure of ecological communities Research Question: What is the ecological succession of abandoned agricultural fields?
Case Study: Succession on Old Fields in Minnesota
• Cedar Creek, MN
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First settled and logged in 1856
First cultivated between 1900 and 1910
Abandoned at various times since the 1920s
Detailed records available
Observations and natural field experiments
Case Study: Succession on Old Fields in Minnesota
• Through half a century of succession, a number of patterns become evident through observation
• Now a Long Term Ecological Research (LTER) station:
Cedar Creek Natural History Area (Univ. of Minnesota)
OBSERVATIONS
(Inouye et al 1987 Ecology)
Case Study: Succession on Old Fields in Minnesota
• Unfortunately, these observations fail to establish a mechanism for the observed patterns
– Only correlations between time and the response variables
– Is field age causing the observed pattern?
– Or is the causal agent nitrogen, which is correlated with field age?
• TEST EXPERIMENTALLY!
Case Study: Succession on Old Fields in Minnesota
•Research question: Do patches receiving similar supply rates of nitrogen become more similar over time?
17g N m-2 yr-1
1g N m-2 yr-1
Conclusion: ‐ Patches receiving similar supply rates of N become more similar. ‐ The higher the supply rate, the faster the convergence to high similarity.
Building Theory: succession responds to an interaction between time and nutrient supply rate
Today’s Topics
•What is ecology?
–scientific study of the distribution and abundance of organisms, and the interactions that determine distribution and abundance
•Ecology and environmentalism
–Science vs social concern
•Three fundamental points (the course goals)
–Multiple scales
–Multiple forms of evidence
–True scientific methods and rigorous statistics
•Agricultural succession •Syllabus
Evaluation for the course
• Midterm: 30%
• Final: 40%
– cumulative, but focused on the last half of the course): • Blog Assignment
30%
– Write blog
– Reply to another blog
20 pts
10 pts
• If you have special test needs or other concerns, please see me or email me, and make sure you contact the Disabled Student’s Program at UCSB.
Class policies
• Get here on time. • If you’re late, you disrupt me and the other students.
• Don’t come if you are sick. You can borrow someone’s notes‐‐
lecture slides will be posted
• Complete blog assignment on time. Late blogs marked down 2 pts per day.
• Academic honesty
– Don’t plagiarize other people’s work
• Cite authors when you quote their research
• Cheating in any form is immoral and a serious academic offense
Crashers
• If you are not yet enrolled (course crashers)
– Come see me after class
– The class is offered in the fall and there are currently at least 50 spaces open Course Schedule
• Class flow
• Guest lecturers
• Exam dates are within class time
• Blog sign up • Possible changes!
Blog topics
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Topic 1: Biogeography and Evolution
Topic 2: Species Interactions
Topic 3: Biodiversity
Topic 4: Food Webs and Ecosystem Ecology
Topic 5: Threats to Ecosystems
Topic 6: Tools and Solutions to Environmental Threats
• (Guidelines and example post on gauchospace)
Research for blog assignment
• Web of science article database
– Scientific literature (peer reviewed journals)
• Science Daily
– News
• Begin your own searches today for your blog post!
Madagascar endemic species‐
(native exclusively to a particular region)
Uroplatus, Leaf‐tailed geckos
sleep with heads flattened to tree trunks and alter body colors for camouflage
Adansonia or baobab tree 8 species total and 6 in Madagascar (1 to mainland Africa and Arabian Peninsula and 1 to Australia)
Endemic pollinators
• 24 of 36 bat species are endemic • The 3 species of fruit bat play an important role in the pollination of Baobab trees, especially in deforested areas
Madagascar Flying Fox, Pteropus rufus
(wing span > 1 meter)
24 recognized endemic species and 3 invasive species; endangered giant rat jumps like a kangaroo, Giant jumping rat
~13 in and 2.6 lbs!
Small primates, or prosimians=“pre‐primates” Lemur=“ghosts or spirits” from Roman mythology; endemic to Madagascar and Comoro Islands ~100 species; ex: the Aye‐Aye can rotate its middle fingers 360 degrees for eating grubs and fruit!
fossa
Aye‐Aye
Striped civet
Eupleridae family: 8 endemic species from this ancestor, closely related to mongoose; fossa and civet are most ancient of this group; the cat‐like fossa is largest mammal carnivore, preys on lemurs; the fox‐like civet is small ~18.5 in and ~2.5 lbs
Ring‐tailed lemurs
streaked tenrec
Endemic, insectivore mammals resemble hedgehogs, shrews, opossums, mice and otters—due to convergent evolution; ~30 species in Madagascar
Biodiversity loss Madagascar’s status:
• 204 extant mammal species in Madagascar • 6 are critically endangered • 30 are endangered • 30 are vulnerable • 6 are Near‐Threatened
• 66 are either Data Deficient or not evaluated.
Threats to biodiversity:
• Habitat destruction and fragmentation
• predation and competition from introduced species
• Harvesting from humans Blog topics
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Topic 1: Biogeography and Evolution 
Topic 2: Species Interactions
Topic 3: Biodiversity 
Topic 4: Food Webs and Ecosystem Ecology
Topic 5: Threats to Ecosystems
Topic 6: Tools and Solutions to Environmental Threats
see my example blog on Gauchospace