Diversity

Question 1

What is conservation biology?

Answer 1

An integrated, multidisciplnary scientific field that has developed in response to the challenge of preserving species and ecosystems

Question 2

What are the three aims of conservation biology?

Answer 2

1. To document full range of biodiversity on earth
2. To investigate human impact
3. Approach extinction prevention, resotre communities

Question 3

What is biodiversity?

Answer 3

“The variety of life, encompasses all forms, levels, and combinations of natural variaiton, at all levels of biological organization”

Question 4

What are the three levels of biodiversity?

Answer 4

• Ecological
• Genetic
• Organismal

Question 5

Biological species definition

Answer 5

A group of individuals that can potentially breed among themselves in the wild and do not breed with individuals of other groups

Question 6

Morphological Species definition

Answer 6

Group of individuals that appear different from others, are morphologically distinct

Question 7

What is evolutionary species definition?

Answer 7

Group of individuals that share unique similarities in their DNA and hence their evolutionary past

Question 8

What is species richness

Answer 8

The number of unique species in a collection or set of observations

Question 9

What are 3 reasons species richness estimates may be innacurate?

Answer 9

• Inventories are incomplete
• Described species tend to be larger bodied, more abundant, and more widespread
• Distributions are best known for temperate regions

Question 10

Heterogenous biodiversity distribution meaning

Answer 10

Biodiversity is distributed ‘unevenly’
Some areas are largely devoid of life whilst others are hyperdiverse
desert vs. rainforest

Question 11

What is a biodiversity hotspot?

Answer 11

Areas with an exceptionally high concnetration of endemic species and are undergoing exceptional loss of habitat

Question 12

What are the two strict criteria to qualify as a biodiversity hotspot?

Answer 12

• Contain at least 1500 species of endemic vascular plants
• have lost at least 70% of its primary native vegetation

Question 13

What is the latitudinal gradient in species richness?

Answer 13

Species richness peaks at the equator

Question 14

What is the species-energy relationship?

Answer 14

The amount of available energy in an area impact levels of diversity

Question 15

How are evapotranspiration and potential evapotranspiration used in the species-energy hypothesis?

Answer 15

• Evapotranspiration measures the simultaneous availablility of water and solar energy
• potential evapotranspiration reflects the energy available to evaporate water to the atmosphere

Question 16

What is the productivity hypothesis?

Answer 16

Energy constrains richness via trophic cascades
(Richness is limited by available energy)

Question 17

What is the ambient energy hypothesis?

Answer 17

Solar energy impacts organisms and diversity through their physiological response to temperature
- more costly to live at higher latitudes (out of thermal neutral zone)

Question 18

Is water or water energy the primary predictor of plant richness?

Answer 18

In tropical areas - water variables are best predictors
In cool areas, water energy variable are best predictors

Question 19

Is water or energy the primary predictor of vertebrate richness?

Answer 19

In warm areas water is most associated with richness
In cold climates, ambient energy is most associated

Question 20

What were the two largest mass extinctions?

Answer 20

The Cretaceous (dinosaurs) and the Permian (50% of animals)

Question 21

Where are the highest extinction rates and why?

Answer 21

On islands (flightless birds)
- Small populations and low dispersal

Question 22

Why are freshwaters imporant

Answer 22

They hose 1/4 of vertebrate diversity while they only cover a small portion of the Earth’s surface

Question 23

What is the current estimated extinction rate vs the background extinction rate?

Answer 23

0.1-1 E/MSY (background)
vs
1 E/MSY (current)

Question 24

What is a global hectare?

Answer 24

A biologically productive hectare with world average biological productivity for a given year

Question 25

Biocapacity

Answer 25

Area of productive land available to produce resourves or absorb carbon dioxide waste, given current management practice

Question 26

What is the available biocapacity per person on our planet?

Answer 26

1.7 global hectares

Question 27

What are the 5 main pressures on biodiversity

Answer 27

1. Habitat loss and degradation 2. Climate change 3. Pollution and nutrient loading 4. Overexploitation and unsustainable use 5. Invasive species

Question 28

Habitat fragmentation 3 effects on land area

Answer 28

1. Habitat fragments differ from original habitat 2. Fragments have a greater amout of edge for area 3. Centre of each habitat fragment is closer to an edge

Question 29

Why is larger edge due to habitat fragmentation bad?

Answer 29

1. Microenvironment at edge is different from interior 2. Edge is disturbed habitat 3. Brings wild populations in contact with domestic plants and animals

Question 30

What are three effects of habitat fragmentation on populations?

Answer 30

1. Limit potential for dispersal and colonization 2. Reduce foraging ability 3. Precipitates population decline by dividing up existing population

Question 31

What is extinction debt?

Answer 31

The future extinction of species due to events in the past (time lag)

Question 32

Explain species area curves

Answer 32

There is often a positive relationship between area and the number of species - slope is steeper in fragmented landscapes due to greater species lost

Question 33

Eutrophication

Answer 33

Human sewage and fertilizers release large amounts of nitrates and phosphates into freshwater systems Leads to eutrophication Leads to hypoxia

Question 34

Overexploitation

Answer 34

When harvest rate of any population exceeds its natural replacement rate, through reproduction or immigration

Question 35

What are the "missing fish"

Answer 35

FAO data of fish exploitation is probably underestimated due to artisanal and subsistence fisheries, bycatch, illegal and unreported catch

Question 36

What is the fishing down process

Answer 36

Successive loss of the largest individuals and species in favor of smaller, faster, and shorter-lived fish

Question 37

The bushmeat crisis

Answer 37

Populations of large primates, ungulates, and other mammals may be reduced by 80% or more - "half-empty forest"

Question 38

How does habitat loss effect community dynamics?

Answer 38

- Some plants rely on dispersal by species - Control by grazing - Disrupt nitrogen cycling - Reduced competition - Habitat engineers