Week 2-5

Question 1

What is a population?

Answer 1

A discrete group of individuals from a single species in a relatively self contained space, where there is little immigration and emigration relative to the intentional rates of recruitment and mortality

Question 2

What increases population isolation (i.e decrease in immigration and emigration)

Answer 2

Geographical barriers such as rivers and mountain ranges, as well as habitat fragmentation cause by deforestation.

Question 3

Why do populations generally have the same gene pool?

Answer 3

Because populations tend to be isolated and thus can not move breed with other individuals from a different population

Question 4

What can regulate population size?

Answer 4

Habitat size, quality, fragmentation
predator population
competing species
climate/optimal conditions

Question 5

What is the difference between population size and population density?

Answer 5

size = total number
density = number per unit of space

Question 6

What is a fundamental niche?

Answer 6

is the combination of environmental conditions and resources where a species COULD survive and reproduce

Question 7

What is a realised niche?

Answer 7

Is the area of the fundamental niche where a species actually exists after interacting with other species and being out competed from some regions

Question 8

What determines the limits of the geographic ranges?

Answer 8

Abiotic/biotic factors that prevent further spread
Human transformation of the landscape e.g farming, deforestation
Local population dynamics at the edge of the range
Genetic mechanisms

Question 9

How can knowledge in population ecology apply to the real world

Answer 9

Conservation of endangered species
Harvesting/management of natural resources
Invasive species biology
Pest control
Spread of diseases

Question 10

Which region hold the highest level of biodiversity

Answer 10

Tropical

Question 11

What did the Millennium Ecosystem Assessment say about tropical forest

Answer 11

It said that habitat change has placed a very high stress on tropical forest and unless anything is done the impact of this stress will rapidly increase

Question 12

How much of the Atlantic Forest has been lost`

Answer 12

95%

Question 13

How much the Mediterranean and temperate did Millennium ecosystem assessment
say are lost

Answer 13

70%

Question 14

How much semi-natural habitats in the UK have been lost since 1940 on average

Answer 14

70%`

Question 15

Give an example of a location, with time period, which has suffered fragmentation and a quantified amount of loss

Answer 15

Heathland Dorset: 1759 – 1978 (86% loss)

Question 16

What is the relationship between landscape structure, population dynamics and ecological processes

Answer 16

Landscape structure can affect the other two

Question 17

What is the species-are realtionship

Answer 17

It is the positive relationship between the size of an area and the number of species found within it

Question 18

Why is the species relationship positive

Answer 18

Large areas tend to have more niches which different species can in habit
Isolation is more likely to occur in large areas and so speciation is more likely to occur.

Question 19

What were the main findings of Ferraz et al. (2003)

Answer 19

A 10-fold decrease in the rate of species loss requires a 1,000-fold increase in area. Fragments of 100 hectares lose one half of their species in <15 years, too short a time for implementing conservation measures.

Question 20

What is the impact on fragmentation on different species of bird

Answer 20

Different species have different tolerance levels to fragment size e.g blackbirds reached 100% breeding probability in woods less than 1ha but marsh titis needed over 15ha to reach 100% breeding probability

Question 21

What aspects of population dynamics does landscape structure affect

Answer 21

Dispersal + colonisation
Persistence
Productivity
Synchrony
Gene flow
Spatial density dependence
Buffer effects

Question 22

Which ecological processes does landscape structure affect

Answer 22

Predation, herbivory, pollination

Question 23

example of pollinator being affected by fragmentation and by who

Answer 23

Euglossa sp. abundance fell as fragment size decreased Powell and Powell (1987)

Question 24

example of plant reproductive success being affected by fragmentation and by who

Answer 24

In Sweden the mean number of seeds set per flower of maiden pinks were lower in fragmented habitats than continuous
due to a 2-3 fold decrease in pollinator visitation (Jennersten 1988)

Question 25

What are the potential consequences of fragment caused changes in pollinators

Answer 25

Fragmentation can restrict pollen flow which may reduce both the genetic variability or progeny and the effective genetic neighbourhood size which in turn increases the risk of inbreeding depression and changes in long term stability of isolated populations

Question 26

What is the overall change in biodiversity distribution and who stated it

Answer 26

Moving poleward: in Britain 275 out of 329 species have shifted northward. Hickling et al 2006

Question 27

Define trophic cascade

Answer 27

Trophic Cascade is the theory that food webs are controlled by a top-down process, where top predators affect the abundance or behaviour of their prey, which then has impact on the next lower tropic level.

Question 28

What is shifting baseline theory

Answer 28

Refers to how, with each generation, the accepted norm for ecological conditions lowers since each generation lacks the historical knowledge of how that environment used to be.

Question 29

Example of shifting baseline theory and by who

Answer 29

Pauly (1995) observed that there was a gradual accommodation for the disappearance of fish species and how each gen. of fishery and marine scientists assume that the current fish populations are the norm

Question 30

What is the Hutchinson niche

Answer 30

It is an "n-dimensional hypervolume", where the dimensions are environmental conditions and resources, that define the requirements an individual/species needs in order to survive. The "hypervolume" defines the multi-dimensional space of resources (e.g., light, nutrients, structure, etc.) available to be used by the organism under consideration

Question 31

What's an advantage to the Hutchinson niche model

Answer 31

niche can be measured, mathe­matically manipulated and represented in climo-graphs.

Question 32

What is a meta-analysis

Answer 32

the statistical procedure for combining data from multiple studies

Question 33

How can a meta-analysis be used

Answer 33

can be used to identify common effects and analyse consistency between studies

Question 34

5 stages of a systematic review

Answer 34

``` Defining question Finding the data Summarising relevant data Assessing the quality of the data Analyse and combine the data ```

Question 35

Example of the effect fragmentation has on seed predation and by who

Answer 35

Burkey 1993 found seed predation to be lower at than the interior.

Question 36

What are the consequences of fragmentation affecting seed predation

Answer 36

Seedlings at the edge are less likely to be eaten and thus more likely to survive to germination, however this may be offset by an adverse micro climate. Also it may lead to changes in spatial heterogeneity and survivor ship of the host plant of the seed predator

Question 37

Example of how decomposes are affected by fragmentation

Answer 37

Klein 1982 found that as the no. of dung beetle species went down, so did the rate of dung decomposition with increasing fragmentation.

Question 38

What are the potential consequences of fragmentation affecting decomposers and who suggested them

Answer 38

Potential implication for habitat productivity and the flow of nutrients through an ecosystem since the rate of decomposition has a positive linear relationship with nitrogen and phosphorus concentrations. Enríquez 1993

Question 39

What impact has climate had on marine environments and range shifting (cite)

Answer 39

Perry et al 2005 found that the North Sea winter bottom temp. has increased by 1.6 Celsius in 25 years. There has also been poleward shifts in distributional ranges of some marine species with an average rate of 22km per decade

Question 40

Evidence for climate caused changes in phenology

Answer 40

Parmesan and Yohe 2003 conducted a meta anaylsis on 677 species and found that over a range of 16-132 years, 62% showed trends towards spring advancement e.g earlier frog breeding, bird nesting, first flowering, tree budburst, arrival of migrant birds and butterflies

Question 41

How can climate warming change phenologies generally

Answer 41

It can cause earlier springs, later autumns and increased vegetation activity

Question 42

Describe Keenan et al. 2013 's experiment

Answer 42

Over 20 year they assessed changes in phenology of temperate forest in eastern US

Question 43

What did Keenan et al. 2013 find after their study

Answer 43

They found that carbon uptake through photosynthesis was more than carbon release through respiration.

Question 44

What are the implications of Keenan et al 2013

Answer 44

It suggests current and future increase of carbon uptake due to changes in phenology and since this process is a negative feedback loop it could slow down the rate of warming

Question 45

What is a consequence to changes in phenology

Answer 45

Can lead to trophic mismatch

Question 46

Example of a trophic cascade

Answer 46

A study conducted by Waser et al 2014 in the Elk Mountains, Colorado found that the coyotes avoided a biological research centre due to the high human activity. Since coyotes often feed on the fawns, the does favour these areas and thus the grazing intensity increased the closer one was to the station. This in term affected the seedling recruitment of blue combine and scarlet gilia flowers, which was significantly lower by the station than away where coyotes activity was higher

Question 47

Example of trophic mismatch and by who

Answer 47

Doiran at al 2015 studied the effects of warmer springs on greater snow geese. Warmer springs and earlier snow melt caused the peak nitrogen, an index of the nutritive value in plants, to hit earlier. This resulted in a mismatch between peak nitrogen in the plants and the hatch dates of the geese which had not shifted to earlier in the year. Consequently gosling body mass and structural size at fledging were lower when the mismatch was greater, and thus the fitness of geese was negatively affected. One can presume that this will get worse as warming continues

Question 48

What does the millennium ecosystem assessment say about over exploitation

Answer 48

Overexploitation has a significant impact on biodiversity loss, particularly in marine and tropical biomes

Question 49

What figures did WWF provide for the wildlife population decline between 1970 and 2010

Answer 49

79% of freshwater, 39% terrestrial species, 39% marine species have declined between 1970 and 2010

Question 50

What happens carrying capacity of the environment is exceeded

Answer 50

The environment becomes degraded and the final carrying capacity may end up being lower than the original. Also, the loss of species can lead to trophic cascades that decrease the carrying capacity of the environment for other species

Question 51

What is the symbol for carrying capacity

Answer 51

K

Question 52

What characteristics do K-strategist species typically have

Answer 52

``` Stable environment Large body size Long life expectancy Late maturation High parental care Fewer offspring ```

Question 53

What give K-strategists their name

Answer 53

they are species whose population fluctuate at or near the carrying capacity of the environment they live it

Question 54

What gives r-strategist their name

Answer 54

They are species whose populations are governed by their maximum reproductive capacity.

Question 55

What characteristics do r-strategist species typically have

Answer 55

* Unstable environment * High fecundity * Small body size * Early maturation * Short generation time * Dispersed offspring

Question 56

Define MSY

Answer 56

Maximum sustainable yield is the number of weight of a species that can be removed from the stock of animals without impacting the long-term stability of the population

Question 57

Describe the sustainable yield curve (graph)

Answer 57

the x-axis is fishing effort or fishing mortality, y-axis is yield. The sustainable yield curve begins at the origin and increases. However, the rate of increase decreases until it plateaus. This is the MSY and when a stock is fully fished. If effort or mortality continues to increase, the yield decrease at an increasingly faster rate until the stock is depleted

Question 58

How is the MSY derived from our knowledge of logistic growth

Answer 58

Is a population is assumed to be following logistic growth the MSY will be exactly half of the carrying capacity of the species as this is the stage at which the population growth is the highest

Question 59

Why is it important to understand population density

Answer 59

It is key to the management of natural populations (e.g. conservation or sustainable exploitation)

Question 60

What is a 'close' population

Answer 60

a population with no immigration or emigration

Question 61

What are the two equations used to represent population density in a close population

Answer 61

``` Nt= B-D and Nt+1= Nt+B-D ```

Question 62

Why are abiotic factors density-independent and give examples

Answer 62

Because they regulate population but aren't affected by population density. e.g. Weather and stochastic environmental events (e.g. fire, flood, drought, habitat destruction, spraying of pesticides)

Question 63

What is the relationship between population density, mortality rate and fecundity decreases

Answer 63

Usually, the denser a population is, the greater | its mortality rate and fecundity decreases.

Question 64

When do density-dependent processes occur

Answer 64

when population growth rates are regulated by the density of a population (e.g. competition for mates, competition for resources, diseases, increased predation)

Question 65

How does low prey density affect predators

Answer 65

Low prey density increases the mortality of its predator because it has more difficulty locating its food source

Question 66

Examples of different types of density-dependent processes

Answer 66

competition for mates, resources, diseases, increased predation

Question 67

Describe the relationship between population density, mortality rate and fecundity

Answer 67

As density goes up, mortality rate goes up and fecundity goes down

Question 68

Describe and explain the relationship between population density and intrinsic rate of increase

Answer 68

As population density increases, the intrinsic rate of increase decrease as the are less resources and disease spread is faster

Question 69

What age should one focuses on conserving an r-strategy species and why

Answer 69

The focus should be on the older as they produce lots of young since their is a high chance many wont survive

Question 70

Example of a positive density dependent effect on growth rate

Answer 70

The Allee-effect (Allee 1931) is when population growth rate is very low in a low density population as there is a low chance of finding a mate, which increases as density increases.

Question 71

Example of positive density dependence other than Allee effect

Answer 71

Insects may be attracted to dense patches of a flowering plant species and pollinate them efficiently, but ignore sparse stands.