Samenvatting
Samenvatting Introduction to Animal Ecology
- Instelling
- Wageningen University (WUR)
Samenvatting van de tentamenstof: boek, knowledge clips & tutorials
[Meer zien]Voorbeeld 4 van de 91 pagina's
Voorbeeld 4 van de 91 pagina's
In winkelwagengesponsord bericht van onze partner
Gekoppeld boek
Titel boek:
Auteur(s):
- Uitgave:
- ISBN:
- Druk:
Voorbeeld van de inhoud
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
Voordelen van het kopen van samenvattingen bij Stuvia op een rij:
Verzekerd van kwaliteit door reviews
Stuvia-klanten hebben meer dan 700.000 samenvattingen beoordeeld. Zo weet je zeker dat je de beste documenten koopt!
Snel en makkelijk kopen
Je betaalt supersnel en eenmalig met iDeal, creditcard of Stuvia-tegoed voor de samenvatting. Zonder lidmaatschap.
Focus op de essentie
Samenvattingen worden geschreven voor en door anderen. Daarom zijn de samenvattingen altijd betrouwbaar en actueel. Zo kom je snel tot de kern!
Veelgestelde vragen
Wat krijg ik als ik dit document koop?
Je krijgt een PDF, die direct beschikbaar is na je aankoop. Het gekochte document is altijd, overal en oneindig toegankelijk via je profiel.
Tevredenheidsgarantie: hoe werkt dat?
Onze tevredenheidsgarantie zorgt ervoor dat je altijd een studiedocument vindt dat goed bij je past. Je vult een formulier in en onze klantenservice regelt de rest.
Van wie koop ik deze samenvatting?
Stuvia is een marktplaats, je koop dit document dus niet van ons, maar van verkoper michouweimar. Stuvia faciliteert de betaling aan de verkoper.
Zit ik meteen vast aan een abonnement?
Nee, je koopt alleen deze samenvatting voor €3,49. Je zit daarna nergens aan vast.
Is Stuvia te vertrouwen?
4,6 sterren op Google & Trustpilot (+1000 reviews)
Afgelopen 30 dagen zijn er 70055 samenvattingen verkocht
Opgericht in 2010, al 14 jaar dé plek om samenvattingen te kopen