Revolutionize Your Studying with the [Essentials of Ecology,Begon,4e] 2023-2024 Test Bank
All for this textbook (10)
Written for
Wageningen University (WUR)
Animal Sciences/ Dierwetenschappen
Introduction In Animal Ecology (REG21306)
All documents for this subject (2)
Seller
Follow
michouweimar
Reviews received
Content preview
lOMoARcPSD|2392027
, lOMoARcPSD|2392027
Ch1: Ecology & how to do it
Book
1.1 Introduction
What is ecology => how do we define ecology?
Definition: scientific study of distribution & abundance of organisms & the interactions that
determine distribution & abundance
Coexistence of applied & fundamental (pure) science
- Applied: apply knowledge for own collective benefit
Many questions remain unanswered
Complex science due to uniqueness: different species, genetically different individuals ->
all living & interacting in changing world
- Seek patterns & predictions within complexity
What ecologists try to do:
1. Understand: explain science
2. Describe: before they explain
3. Predict & control
Classes of explanation
1. Proximate
- Why?
- Explain distribution & abundance of species in terms of: physical environment, food
& predators
- What is going on here & now
2. Ultimate
- How?
- Explanation in evolutionary terms
- How did organism get these properties
- Explanation of distribution & abundance lies in ecological experiences of its
ancestors (ch2)
Description => describe what we wish to understand
Directed description
Prediction => what will happen to population of organisms under particular set of circumstances
On basis of these predictions: control, exploit or conserve population
1.2 Scales, diversity & rigor
Ecological phenomena occur at variety of scales
Ecological evidence comes from variety of sources
Ecology relies on truly scientific evidence & application of statistics
, lOMoARcPSD|2392027
Questions of scale
Biological scale (hierarchy):
1. Individual organisms
2. Populations (individuals of same species)
3. Communities (several
populations) Focus on pathways:
4. Ecosystems (community with physical environment)
Range of spatial scales
- Every area (small & large) has an ecology
- 1 cell – gut – rain forest – atmosphere
- Fleas on different bird species – birds in different sized patches of woodland –
woodlands at different altitudes
Range of time scales
- Related to biological hierarchy & range of spatial scales
- Ecological succession (colonization by certain species, accompanied by extinction
of others) => may be studied over different periods of time
- Days – weeks – years
- Appropriate time scales vary
- Need for long-term studies => great value to ecology, but: cost more & require
greater dedication
Diversity of ecological evidence
Ultimately: ecologists interested in organisms & their natural environment
1. Observations & field experiments
- Monitor changing abundance of species over time or space (or both)
- Establish patterns
- Patterns require explanation: analysis of descriptive data and/or manipulative
field experiments
2. Laboratory experiments
- Field experiments costly & difficult, natural field systems may be too complex
- Controlled laboratory experiments often best way to provide answers to specific
questions that are key parts of overall explanation of complex situation in the
field
Simple laboratory systems => basic understanding of simpler communities
3. Mathematical models
- Analysis of ecological communities: constricted & manipulated
Major aim of science is to simplify, but eventually it is the real world we are interested in
- Models & simple laboratory experiments must be judged on similarity on working
of more natural systems
Statistics & scientific rigor
Ecology => search for conclusions in which we can be confident
- No search for statements that have been proven to be true
- Nothing proven with statistics, not what it if for
, lOMoARcPSD|2392027
- Statistical analysis essential for attaching level of confidence to conclusions that can
be drawn
- Science is based on conclusions that are results of investigations carried out with
purpose of deriving those conclusions & to which level of confidence can be
attached (measured on agreed scale)
Ecologists must think ahead
- Statistical analysis carried out after data collection, help interpret data
- Know how they are going to analyze data statistically, not only after & while
collection, but even before they begin to collect it
- Plan: right kind of data & sufficient amount of data -> to address questions they hope
to answer
Ecology relies on obtaining estimates from representative samples
- Draw conclusions about groups of organisms overall (birth rate bears Yellowstone park)
- Almost impossible to sample every individual or entire area -> rely on
representative sample from group/habitat
1.3 Ecology in practice
3 main points:
- Ecological phenomena at variety of scales
- Ecological evidence from different sources
- Ecology relies on scientific evidence & application of statistics
Brown trout in NZ: effects on individuals, populations, communities & ecosystems
Most studies focus on 1 out of 4 levels in biological hierarchy (individuals,
populations, communities, ecosystems)
- However: understanding enhanced when links between levels are made clear
Introduction of exotic fish to streams in NZ
1. Individual level: consequences for invertebrate feeding behavior
- Daytime activity reduced with both fish, but to greater extent when trout is present
- Invertebrates in trout stream more at risk of predation during daylight
2. Population level: brown trout & distribution of native fish
- Where do trout & native species occur?
- Trout directly affects native species distribution (predation)
3. Community level: brown trout causes cascade of events (several populations of
different species)
- Changes also cascade through to other species
- Trout reduce invertebrate biomass, presence of native species did not
depress invertebrate biomass (invertebrates eat algae)
- Algae biomass indirectly increased in presence of trout -> reduction in
invertebrate density & restriction of grazing behavior of invertebrates
4. Ecosystem: trout & energy flow (community with physical environment)
- Hypothesis: rate at which radiation energy was captured through photosynthesis
by algae -> greater in trout stream compared to native fish stream
- Trout stream -> fewer invertebrates -> lower algae consumption rate
- Primary production by algae indeed 6x higher in trout stream
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller michouweimar. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $3.80. You're not tied to anything after your purchase.