1
Q
Queensland hotspot for for tree clearing
A
2/3 the annual rate of deforestation in the Brazillian Amazon.
2
Q
australia’s ecosystem…
A
In a poor states and is deteriorating.
3
Q
____ contributes most to environmental assests
A
Land
4
Q
System of Environmental-Economic Accounting framework
A
an internationally agreed approach for producing comparable statistics on the environment and its relationship to the economy
5
Q
Value of long-term studies:
A
- document the changes
- identify the drivers of change
- provide the evidence and knowledge needed to inform better natural resource management
6
Q
At least ____ Australian ecosystems have been reported to show signs of collapse or near collapse, although none has yet collapsed across the entire distribution
A
19
7
Q
Behaviour
A
part of how organisms respond to the biotic & abiotic environment
8
Q
Fitness
A
an individual’s relative contribution to the next generation’s gene pool
9
Q
does foraging on high quality food provide a fitness advantage?
A
feeding on high quality food increases reproductive output
10
Q
Behaviour is ecologically significant because it:
A
- is a link between individuals & their environment
- affects demographics (population levels outcomes)
- affects interactions among species (community-level outcomes)
11
Q
Behaviour is evolutionarily significant because it:
A
- has some genetic basis (think nature vs. nurture)
- affects fitness
- can be selected (benefits > costs)
12
Q
Behaviour: 3 key aspects
A
- Obtain food
- Avoid becoming food
- Reproduce
13
Q
1.Obtain food
A
- Foraging
- Ambush (camo)
- Active (agile/fast)
14
Q
Optimal foraging theory
A
modelled which food items to eat in a non-depleting environment
* predicts foragers should maximise net rate of food (= energy) intake
15
Q
Marginal value theorem
A
modelled when to leave a food patch in a depleting environment
* predicts that foragers should leave food patches when capture/harvest rate at patch < average capture/harvest rate
16
Q
2.Avoid becoming food
A
- Run away
- Group
- Hide
- Act or be costly
- Feed in safe places/times
17
Q
Costs to anti-predator strategies
A
- Feeding near vegetation cover (missed opportunities to forage elsewhere)
- Grouping (competition for food, social aggression)
18
Q
Behaviour - Reproduce
A
- Courtship & mating behaviour: non-random
- Parental care
- Increased survival & growth of offspring = fitness
19
Q
Sexual selection types
A
- intrasexual selection competition (often ♂-♂) sexual dimorphism (e.g. hefty vs. slight, larger than females)
- intersexual selection mate choice (often by ♀) sexual dimorphism (e.g. flashy vs. plain)
20
Q
Plant behaviour
A
- Leaves/stem grow towards light
- Roots grow along chem gradients
- Different time frame/ way of moving
21
Q
Groups
A
Multiple organisms of same or different species occupying a common space
* Ephemeral or consistent
* Can be social, indirect, or accidental
22
Q
Population
A
A number of organisms of the same species in a defined geographical area
23
Q
Properties of populations include
A
- number of individuals or population size
- area they occupy
- age structure
- sex ratio
24
Q
Importance of population biology
A
- Understand temporal dynamics
- Spatial distribution
- Natural selection
25
Rate (r) =
change / unit of time
26
Variables that drive changes in population size:
* **Birth** & Death
* **Em**igration (number leaving population) & **Im**migration (number entering population)
* **Growth** (individual)
* Age at *maturity*
* **Sex** ratio
27
Population growth in “closed” systems
**No** em/immigration
* Nt+1 = Nt + Births - Deaths
28
Exponential growth
**Geometric**
* population’s per capita growth remains the **same** irrespective of pop size; thus populations grow *faster* as they get *bigger*
29
Discrete pop. growth
**Saw tooth** shape
* reproduction occurs **periodically**
30
Continuous pop. growth
**Curved** line
* reproduction occurs **year-round**
31
Logistic curve
* Growth **exponential** at *low* numbers
* Growth **slows** at *higher* numbers
* Growth **stops** at carrying capacity (*K*)
32
Estimating birth rates
* Histology of **reproductive organs**
* **Capture/counting** of fertilised *gametes*
* **Counting** of newly born *individuals*
33
Estimating death rates (mortality)
* **Tagging**
* **Follow** individuals (for *sessile* organisms)
* **Probability** based (for more *motile* organisms)
34
Population growth in “open” systems
Nt+1 = Nt + Births – Deaths + immigrants - emigrants
35
Mark-release-recapture (MRR)
no. marked/ pop. size = no. recaptures marked/ no. recaptures total
36
Metapopulations
* **Local** populations, but individuals *move*
* Demographic rates *vary* spatially
* Large-scale dynamics *dependent* on local demographics and connectivity
37
Population viability analysis (PVA) factors
* Population Size/Carrying Capacity (**K**)
* **Fecundity**
* **Mortality**: Adults and juveniles
* Inter-annual variation in parameters
38
Factors that contribute to extinction
* **Genetic** stochasticity (*small* populations)
* **Demographic** stochasticity (*random* nature of births and deaths)
* **Environmental** stochasticity (*variability*)
* **Catastrophes**
* **Human** impacts
39
what is PVA used for
determine the long-term vulnerability of a species to **extinction** under a variety of scenarios
40
Biological species concept:
Groups of actually or potentially **interbreeding** natural populations, which are reproductively *isolated* from other such groups
41
Problems with species concept
* Hybridise
* Asexual?
* Fossil taxa
42
Do species really matter?
* Labelling
* History
* Conservation
43
Species richness
= number of **species** in a sample (S)
* *vary* with sample size
44
Species diversity
No. of **species** and no. of individuals in each species
45
Alpha (or α) diversity
**No.** of species within a *particular* areas or habitats
* **Local**
46
Beta (β) diversity
The **difference** in species between areas or habitats
* *Comparing*
47
Gamma (or γ) diversity
**No.** of species from *all* areas or habitats *combined*
* Regional
48
How many species are there: world?
**1.5 – 1.82** million
* More that aren't named/discovered
* Est. ~**2.238 billion**
* *Bacteria*
49
Autotrophs
**Producers**
* Synthesis *organic* from *inorganic* (CO2 etc.)
50
Heterotrophs
Consumers, degraders, decomposers
* *Depend* on **autotrophs**
* Animals
51
Food chains are usually...
**Short**
* *Energy* hypothesis
* *Dynamic stability* hypothesis
52
Energy hypothesis
There is energy **loss** between **trophic** levels
* *high* productivity ecosystems have *longer* chains
53
Dynamic stability hypothesis
Longer food chains less stable because fluctuations at *low* trophic levels **magnify** at *high* levels
* Predictable (**stable**) environments should have *longer* chains
54
Competition
(-/-)
55
Predation
(+/-)
56
Parasitism
(+/-)
57
Herbivory
(+/-)
58
Mutualisms
(+/+)
59
Commensalism
(+/0)
60
Amensalism
(0/-)
61
Obligate mutualism
Symbiosis: partners can **only** survive together
* *Lichens*: fungus and algae
62
Facultative mutualism
Partners gain benefit from associating, but **can** survive on their own
* Caterpillar protected by ants and ants feed of sugary secretions
63
Communities
Two or (usually) more species that **occur** *together* in space and time
* *Interact* with each other as an **ecological unit**
64
Assemblages
A group of *taxonomically* related species living in the **same** place
65
Succession
When an ecosystem develops through distinct **stages** from an *empty* or highly *disturbed* condition
66
Primary succession
**Bare** area *without* soil
e.g. sand-dune, bare rock, mining site
67
Secondary succession
In a habitat *modified* by other **species**
e.g. forest gaps, abandoned agricultural fields
68
Facilitation
Early arriving species make environment more **favourable** for *later* species
* Fixing **nitrogen**, retain water in soil etc.
69
Tolerance
neither negative *nor* positive interactions between early and late species
70
Inhibition
early species **inhibit** later species
71
____ is a driver of species richness and community composition
Disturbance
72
Intermediate Disturbance Hypothesis
Patchy **mosaic** of disturbance creates *highest* diversity
73
Resilience
how long before a *community* returns to an “**equilibrium**” after *disturbance*?
74
Ecosystems
The **community** of living organisms considered in *conjunction* with the **abiotic** components of their environment, interacting as a **system**
75
The water cycle
Processes of **convect**ion, **precipit**ation, **trans**piration and **respir**ation move water around the cycle
76
Nitrogen cycle
Plants **cannot** absorb atmospheric N
Absorbed as **ammonium/nitrate** after *fixation* of nitrogen by symbiotic bacteria/soil
N becomes *limiting* if microbial activity is *inhibited*
77
The carbon cycle
Most carbon is locked up in earth’s rocks as **carbonate** (fossil fuels)
Most *active* pool is **CO2**, 0.04 per cent of the atmosphere ++
CO2 is used in *photosynthesis*, released during *respiration*
Large amounts CO2 *dissolved* in **ocean**
78
Sea otters
Eat **sea urchins** which feast on **kelp**
* Kelp forest = **C storage**
* W/o otters, poor storage of C
79
Phosphorus cycle
**Local**
* Taken up by plants as **phosphate** from sparingly soluble *soil storage pool*
80
Australian enviro conditions
2/3 *desert*
Soils low in **N** & **P**
*Variable* rainfall
* **Pulse & reserve**
81
Silent Spring - Rachel Carson (1962)
Warned of *synthetic* **chemicals** accumulating in mammals and birds
* **Raptors**
* **Bioaccumulation**
* **Pesticides**
82
Bioaccumulation
Occurs when an organism absorbs a *toxic* substance at a rate **greater** than that at which the substance is *lost*
* Occurs in body **tissues**
* Higher **predators** at the top of food chains/webs
83
Toxins introduced in 40s-50s
Herbicides, pesticides, PCBs, heavy metals.
84
Inuit & PCB
PCB found in *breast milk* of mothers
* *contaminated* fish
* eat the *tissue*
* chem **transported** long distances
85
Fractionation
Chemicals **evaporate** from *soils* and carried by **winds**.
86
Distillation
Chemicals from fractionation **condense** in the *cold*
* Toxic **snow** and **rain**
87
Bioaccumulation: effects on growth and development
* *Long-term* **tissue** effects
* **Lethal** in many species
* Effects on **developmental** problems
88
Oil impacts on coastal communities
**Clean-up** can be as *damaging* as the oil itself
* Strong pervasive biological interactions in rocky intertidal and kelp forest communities contribute to *cascades* of **delayed, indirect** impacts and expand damages, delay recoveries
89
Biomass collapse
**Fragmented** landscape
* Land clearing
* Burning
* *Decline* in **above-ground biomass** after
90
Ecological meltdown
Mostly **large** animals and **predators** *lost*
* Hyperabundancy of **small** animals
* Plants **cannot** keep up with demands.
91
Climate change impact on plants and animals
* **Range** shifts (latitudinal/altitudinal)
* **Abundance** changes
* Change in **growing** season length
* **Earlier flowering**, emergence of insects, migration and egg-laying in birds
* **Morphology** shifts
92
Climate change impact on hydrology and glaciers
* **Shrinkage**
* Permafrost *thawing*
* **Later** freeze & **earlier** *break up* of river/lake ice
93
Effects of loss of ice
Species favouring *ice-dominated* systems with ***shallow benthic** communities* will diminish and be **replaced** by systems dominated by **pelagic** fish
94
Pollutants...
* Lead to *fitness* **declines** in species (*accumulation*)
* Are **mobile**, *can't* be easily managed at the *local* level
95
Australia’s recent mammal extinctions
* Lost ~**34** species in 200 yrs
* Critical weight range = **5.5-35**kg
96
Aims of Conservation Biology
1. To *describe* **problems** and understand **processes**
2. To *predict* impacts of **threats**
3. To *develop* **solutions**: undo the ‘human footprint’
4. Ultimately: **stop** more species/communities/ecological processes going *extinct*
97
Jared Diamond’s “**Evil Quartet**” of extinction forces
1. **Alien** species
2. **Over**-hunting
3. Habitat **loss**
4. **Co**-extinction
98
Edward O. Wilson’s “**HIPPO**” of extinction forces
1. **Habitat** *destruction*
2. **Invasive** species
3. **Pollution**
4. **Human** over-population
5. *Over*-**harvesting**
99
Key diff. between Evil Quartet and HIPPO
HIPPO included **human** over-population, *underpins* everything else.
100
Alien species NZ & AUS
* **NZ** *more* **alien** than native
* **Aus** *56* introduced species of *vertebrates*
101
Our new Megafauna
New **invaders** brought new megafauna
* 200-100 years ago with *Europeans*
* Cattle, sheep, goats, pigs, buffalo, donkeys, deer, horses, and camels are now all *feral*
* Many are major **pests**
102
102
Our new “Microfauna”
* **Cats, rats, mice** arrive with early explorers
* Rabbits, hare, foxes, **cane toads** and others released
* + **bees, wasps, new plants** (e.g., blackberry, lantana, gorse, buffel), ants and much, much more
103
Invasion
1.*Deliberate* introductions
2.**Human** traffic
3.*Native* **invaders**
4.*Success* rates for invaders
104
“Tens rule”
* 1 in 10 of the plant and animal species *brought* into a region will **escape** to appear in the wild
* 1 in 10 of those *escaped* species will become **naturalised**
* 1 in 10 of these will become **invasive**
105
Invasive species tend to have characteristics that :
1. *maximize* or enable *high* **reproduction**
2. enable great ecological **dispersal**
3. enable species to be greatly ecologically **flexible**
4. cf. traits of **pioneer** species in *succession*
106
Overhunting
* **Bounties**
* **Fisheries**
* **Bush**meat
* Over exploitation risks **higher** in *data-deficient* systems
107
Habitat loss and the extinction debt
Habitat destruction **major** cause of species **extinction**
* Extinction **debt** reflects the future ecological *cost* of current *habitat destruction*
108
Co-extinction
Critical ecosystem **functions** lost when *species* are lost
* Cascade
109
Solutions to extinction: Experiments
Key to identifying processes **driving** extinction and allowing **management** and future predictions.
* **Predation** experiments (removal/supplementation)
* **Meta-analyses** – towards a general pattern across experiments and studies
110
Operation Western Shield
* **1080** poison used
* Brush-tailed bettongs *removed* from **endangered** list, numbats, rock-wallabies, possums, bandicoots and chuditch also more common
* Successful **mammal conservation** program
111
Modelling
Useful to *predict* impacts and to identify management options (**PVA**)
* **Comparing** *management* options
* *Minimum* viable population (**MVP**) size
* Data *hungry* process, but very helpful and effective
112
Legislations
* **Federal** listing
* Provides **recovery** plans
* Identify *critical* habitats
* List **threatening** processes
113
Ecological restoration
Process of **repairing** damage caused by **humans** to the *diversity* and *dynamics* of indigenous ecosystems
* Restoring ecosystems to some **pre-impact** or **reference** state
* Enhancing habitat **quality**
* Restoring ecosystem **functions** via *reintroductions*
114
Succession of plant species
Follows a pattern of **pioneer species** occupying an area which was disturbed
* Consist of **annual** plants and these are replaced by **perennial** plants and grasses, shrubs and then trees as the community moves *toward* being comprised of **climax** species.
BIOL1007
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