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Flashcards in Biodiversity, Ecology and Conservation Deck (260)
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1

Definition of ecology

Interaction between organisms (biotic) and their environment (biotic and abiotic)

2

Definition of biological species

Two organisms which cannot breed to produce viable, fertile offspring

3

Definition of population

A group of individuals of 1 species living and interacting in one area at a given time

4

Definition of community

Associations of populations of 2 or more different species in the same area

5

Definition of ecosystems

Community and physical environment and the transfer between different trophic levels in the whole environment

6

Definition of landscapes

Areas with considerable differences e.g. multiple ecosystems

7

Definition of biosphere

All the world's ecosystems i.e. all living organisms and their environment

8

Definition of assemblages

A group of similar animals e.g. an assemblage of birds

9

Definition of population dynamics

How population size varies through time

10

Basic population equation and what it is used to calculate

Nt+1 = Nt + B - D + I - E
To calculate population size for animals with annual breeding cycles

11

Definition of geometric growth

Species population changes in size by a constant proportion in discrete time steps

12

Definition of exponential growth

Species population with continuous reproduction changes in size by a constant proportion at each instant in time

13

When does unlimited population growth occur?

- no competition and unlimited resources
- in small populations
- Newly colonised regions
- e.g. Muskox, Alaska

14

Important population measures

1. Population size i.e. number of individuals
2. Population density i.e. number of individuals/ area or vol

15

What are area-based counts

Count sessile individuals or vegetation using quadrats or aerial surveys for large mammals in a known area

16

What are distance-based counts

Measure distances individuals seen from a transect line/ point to estimate relative number of individuals/ unit area

17

Definition of relative population size

Number of individuals in time/ place relative to a number in another

18

Methods used to measure population sizes

1. Area-based counts
2. Distance-based counts
3. Capture, mark, release, recapture

19

Capture, mark, release, recapture equation to estimate population size

Total population (N) = (Number marked first catch (M) x total caught second catch (C) / number marked second catch (R)
N = (M x C)/R

20

Assumptions and issues with capture, mark, release, recapture

1. No B, D, I or E between M and R i.e. equal chance of capture
2. No harm during process
3. Marks do not fade
4. Overestimate if animals learn to avoid recapture
5. Underestimate if animals get preferentially caught

21

Definition of intraspecific competition

Competition within members of the same species as similar resource requirements i.e. demand>supply

22

Definition of interspecific competition

Competition between different species where both suffer negatively

23

Definition of carrying capacity (K)

The upper sustainable limit of a population

24

Begon et al. (1996) intraspecific comp. characteristics

1. Effect is a measurable reduction in an individual's contribution to future generations
e.g. a) fecundity (Cain 2011) - song sparrow breeding pairs and offpsring survival b) survivorship (van Balen 1980) - supplementary feeding and great tit breeding pairs
2. Resources must be in limited supply
3. Reciprocity e.g. bird of prey chicks, spadefoot toad phenotypic plasticity
4. Density dependent e.g. Tribolium confusum, soybean survivorship

25

Population growth models

1. Exponential growth equation
2. Discrete logistic growth equation

26

Exponential growth equation

Nt+1 = reproductive rate x Nt

(Nt = pop. size)

27

Discrete logistic growth equation

Represents intraspecific competition
Nt+1 = reproduction rate x Nt (1 - Nt/K)
- calculate N at different time phrases
- plot Nt (y) against time (x) to see population growth

28

Characteristics of density dependence

- closely linked to intraspecific competition
- regulates population sizes around an optimum K value

29

Population regulation

1. Regulating equilibrium around K by DD factor regulation (pop. often fluctuates)
2. DD factors do not regulate if there is a time delay or if it only regulates in certain environmental conditions
3. Different factors, e.g. food, waste, predation, may cause DD

30

What is cobwebbing (Ricker-Moran plots), how to use them and features?

Graphical method to predict the results of intraspecific competition and show population dynamics
- plot curve represented by the discrete logistic growth equation
- plot straight line to present unchanging population around K
- plot graph N against time
Changes to curve shape can majorly impact population stability and dynamics
Patterns vary i.e. cycles, oscillations, fluctuations