Field Bio Exam 1

Reasons for doing field research

Observational, Experimental, and Applied

1) Making observations and establishing baseline data (O)

2) Tracking patterns and trends (O)

3) Testing an idea/theory/model (O-E)

4) Adding additional knowledge or data in support of

existing scientific understanding (O-E)

5) Practice/training (O-E-A)

6) Application/management (E-A)

Observational studies

observations and surveys in which not particular theory/model is being tested, and no experimental manipulations take place

Experimental studies

experimental manipulations of the system are designed to test particular theories/models and elucidate the mechanisms producing observed patterns

Correlation and causation

Correlation - things line up, they match

Causation - a direct relationship where an action by one variable causes a change in another

Weak vs strong inference

Weak inference - When a causal mechanism is inferred from pattern or correlation, without experimental demonstration

Strong inference - When experimental demonstration is used to infer conclusions and disprove multiple hypotheses at a time

Applied science

Known, well-established theory is applied to a system, and the system is manipulated to achieve targeted goals/outcomes

Basic science

Expands fundamental knowledge and understanding

Planning a study: Scope of inference

What question we’re trying to answer, or what problem we’re trying to solve?

• What “Population”?- What objects/variables are you hoping to collect data on?

• What Spatial Scope?- Subsamples from a site, multiple sites, landscapes, etc.

• What Temporal Scope- One day, one field season, three years, etc.

What is the difference between pattern and process in ecological theory?

Pattern - observed arrangement

Process - what causes the pattern

Ockham’s Razor or the principle of parsimony

“All things being equal, the simplest answer tends to be the best one”

Benefits of Pilot Studies

•Establishing whether the sampling frame and technique

are effective

•Assessing the feasibility of a (full-scale) study/survey

•Designing a research protocol

•Identifying logistical problems which might occur using

proposed methods

•Estimating variability in outcomes to help determining

sample size

•Collecting preliminary data

•Determining what resources (finance, staff) are needed for

a planned study

•Developing a research question and research plan

•Training a researcher

•Convincing funding bodies that the research team is

competent and knowledgeable

•Convincing funding bodies that the main study is feasible

and worth funding

•Convincing other stakeholders that the main study is worth

supporting

Abundance vs Density

Total number of individuals in a population vs number of those individuals per unit

Complementarity population model

that the niches each species holds results in such unique resource use that the loss of any species would reduce ecosystem function

Redundancy population model

species functions are substitutable

Facilitative population model

As species richness increases, functionality increases

Intrinsic vs extrinsic

Caused by the species inherent characteristics vs caused by human activities that have resulted in limited distribution and abundance, independent of their biology

Intrinsic causes

Slow life histories, large area requirements, occupying higher trophic levels, complex social structure, high specialization, low vagility, large body size

Extrinsic causes

Habitat modification, pollution, exploitation, biotic mixing (invasives)

Different ways of defining rarity

Geographic range, local abundance, and habitat specificity

Based off abundance and distribution within the context of other species that are ecologically or taxonomically similar

Preston’s Veil

Rather than being skewed, where most species are rare, and few are common, the reality may be that there is a missing part of the graph, in which a few species are so rare that we aren’t even detecting them

Three purposes in animal behavior (autoecology)

eat, not be eaten, reproduce

Taxis vs Kinesis

Directed motion in response to a cue vs random search/motion in response to a cue

Energy Budget

'Profit' = net food value divided by time required to obtain & handle the food item, and efficient foragers should select most profitable prey! (?)

Optimal Foraging

Any food item has both a cost (time, energy, risk, etc) and a benefit (net food value). The relative value of each of these determines how much 'profit' a particular item represents

Ideal Free Distribution

The number of organisms competing for a resource at different sites is proportional to the resource distribution among sites. The relative number of individuals using any two patches matches the relative availability of resources in those same two patches.

Liebig’s Law of the minimum

In any system, a population will be limited by some (one) resource that is the most scarce relative to need.

Gause’s Law (competitive exclusion)

Two (or more) species with identical niches cannot coexist. Weaker competitors will be excluded (the competitive exclusion principle).

Niche Partitioning

Because competition negatively impacts individual fitness, selective pressures act to eliminate overlap in resource use among competing species

Fundamental vs realized niche

Where/what organisms would do alone/naturally vs what actually happens

The theoretical total potential niche space for a species. vs The actual real-world niche space for a species

Core-periphery structure in populations

More species/individuals found in core where the most resources are

Core - high fecundity

- high survivorship

- abundant resources

- high population density

- per capita reproduction > 1

Periphery- low fecundity

- low survivorship

- competition for resources

- low population density

- per capita reproduction < 1