Ecosystem Management and Conservation

Question 1

What are communities?

Answer 1

Direct and indirect effects of competition, predation, and parasitism, with dominant and keystone species playing major roles.

Question 2

How are ecosystems maintained by inputs of energy and nutrients?

Answer 2

Allochthonous - Receives a majority of nutrients from outside.
- Leaf debris from riverbank in stream communities.
- Rain of detritus to abyssal zone of oceans.

Autochthonous - Self-contained internal nutrient supply.

Question 3

What is the large-scale study of ecosystems?

Answer 3

Landscape ecology

Question 4

What are critical species interactions?

Answer 4

Keystone species interactions
- Predator
- Food resource
- Ecosystem engineer

Question 5

Do we prioritize keystone species?

Answer 5

Not necessarily..
1. Keystone means different things to different people.
2. Different effects of keystone species
3. Focus on keystone could fail to protect other species
4. There is a range in strength of species’ effect.

The combination of some non-keystone species may have even greater effects.

Question 6

How can overpredation affect diversity?

Answer 6

• Rare species are secondary prey
• By-catch

Question 7

For a species to be of conservation concern what factors need to be in place?

Answer 7

Conservation threat to a species particularly due to predation, depends on the ecosystem in which it is found and that species resilience.

Question 8

What is hyper-predation?

Answer 8

Top predators consume lower predators.

Question 9

What is Apparent competition?

Answer 9

Where two species that do not directly compete affect each other indirectly by being prey to the same predator.

Question 10

Provide some examples of apparent competition..

Answer 10

Study in Kenya on lion preyingon Zebra and hartebeest.
Zebras the priamry prey but lions select hartebeests.

Question 11

What is a mesopredator release?

Answer 11

Removal of top predators can result in a linear trophic cascade -> increase in lower predators-> decrease in prey.

E.g. Iberian lynx in pain depredates Egyptian mongoose and rabbits.

Question 12

What four conditions allow refuge from predation (bottom-up regulation)?

Answer 12

Body size - Small mammal species are vulnerable to predation.

Migration - Escape from predators/ access to ephemeral, high-quality food resources.

• Low diversity ecosystems- Single predator with one or a few prey species.
• Smaller ungulates experience more predation -> top-down regulation.

High diversity communities:
- Limitation of herbivore species determine by its place in the hierarchy of herbivores.

Question 13

What are the ecosystem consequences of bottom-up processes?

Answer 13

Mammals may not be numerous compared to some animal groups, but their impact is considerable:
- Determine physical structure of habitats
- Alter rates of ecosystem processes such as nutrient flow, growth rate, and decomposition.
- Dictate species diversity.

Question 13

What happens if different trophic species are lost?

Answer 13

Top carnivore -
Increase in abundance of small predators, overgrazing etc.
Large herbivore-
Habitat succession and reduced diversity
Pollinators & seed dispersed -
Reproduction & recruitment failure of certain plants
Parasites-
Population explosion of host species.
Mutualists with defensive properties
- Increased predation and disease of plants.

Question 13

What are the different trophs within trophic levels?

Answer 13

Autotrophs
Heterotrophs

Question 13

Why is disturbance important?

Answer 13

It can be Deterministic or Stochastic …
Fire- Intentionally caused by human activity (Deterministic)
- Naturally occurring wildfires.

Disturbance generates biodiversity.

Question 14

What traits of species tend to be successful invaders?

Answer 14

• High reproduction rate- Short generation time.
• Long-lived
• High dispersal, broad range, and diet
• Habitat generalist
• Human commensal

Question 15

What communities might be invadable?

Answer 15

• Early successional - less niche dense - not at equilibrium.
• Low diversity of native species
• Absence of predators or species ecologically similar to invader
• Absence of predators in history (Naive)

Question 16

What can over abundance of native species cause?

Answer 16

Reduced natural diversity
Disease and parasite spread
Local extinctions

Question 17

What are the four basic principles for good conservation management?

Answer 17

1. Critical ecological processes must be maintained
   - Ecosystem approach (best!)
   - Focus on important species
2. External threat minimized and external benefits maximized
3. Evolutionary processes must be conserved
4. Management must be adaptive and minimally intrusive.

Question 18

Provide examples of management at different scales.

Answer 18

Population -
Perform some population viability analysis to assess the minimum pop size needed for persistence.

Ecosystem -
Use prescribed fire to maintain levels of vegetation heterogeneity

Landscape -
Protect riparian wetlands from chemical runoff by placing buffer areas between agri-fields and wetlands.

Question 19

What are the contrasts between traditional and ecosystem management?

Answer 19

Traditional -
- Focuses on economics and resource extraction
- Equilibrium perspective
- Prescription- command and control
- Site specificity
- Often confrontational - public seen as adversaries.

Ecosystem
- Emphasis on balance between Ecol processes and commodities, amenities
- Nonequilibrium perspective
- Acknowledges uncertainty and flexibility (adaptive)
- Attention to context
- Public invited as partners

Question 20

How did the storm on south island in 1968 (The Wahine storm) Effect Black swans?

Answer 20

Beds of macrophytes were destroyed, which caused physical changes in lake sediment that prevented return.
Black swans dropped from 80,000 -40,000 to 10,000 and have not recovered.

Question 21

What are the different terms used to encompass ecosystem functions?

Answer 21

Ecosystem processes, services and goods.

Question 22

Name some examples of Ecosystem processes?

Answer 22

Hydrology
Biological activity
Bio-geographical cycling
Decomposition
Resilience
Robustness-fragility

Question 23

Name some ecosystem services?

Answer 23

Maintaining hydrological cycles
Regulating climate
Purifying water and air
Pollinating plants
Cycling nutrients

Question 24

Name some ecosystem goods?

Answer 24

Food and clean water
Construction materials
Medicinal plants
Wild genes
Replacement species
Biological control agents
Tourism

Question 25

What is ecological restoration ?

Answer 25

Not harming the environment whilst identifying and deals with processes which have lead to degradation.
Determine realistic goals and measures of success.
Monitor the restoration and assess success.

Question 26

What is a restoration process?

Answer 26

1. Restore to ‘natural state’
2. Create a system with favourable traits.

Question 27

Outline succession.

Answer 27

1. Habitat is disturbed - leaving residuals or legacies
2. Animals and plants invade the area
3. Species become established and interact (Competition, predator-prey etc)
4. Often change the condition of a site
5. Changes persist until a type of equilibrium is reached.

Much of restoration involves manipulation of succession.

Question 28

What are the keys to a successful restoration project?

Answer 28

1. Judgements - excellent data and ecological expertise.
2. High social commitment (engagement)
3. Ecological circumstances - less damage the better
4. Values - biocentric or enlightened anthropocentric