W5: L22 = Systems Ecology [Functional Ecology] (Prof. Sally) Flashcards
Why was the Bird, Flower, Insect example too simple? (2)
It’s because:
- It depends on the type of bird (some birds are pollinators).
- It depends on the type of insect (some insects eat flowers).
Why was the Grass, Tree, Fire example too simple?
It’s because some species of trees are flammable, so when these trees are in the system there is a positive feedback from trees to fire.
Why is it useful to take a functional approach? (3)
- It can help us to understand the ecosystem consequences of changing biodiversity.
- Organism respond to environments based on their functional attributes.
- Organisms affect environments based on their functional attributes.
Function/Functional attributes? (3)
- Designed to be practical & useful, rather than attractive.
- Designed for/adapted to a particular function/use.
- We use the word “functional” in an evolutionary context (i.e., in terms of adaptations to environmental conditions).
Systems ecology attributes? (3)
- Focuses on interactions & transactions within & between biological and ecological systems.
- Concerned with the way the functioning of ecosystems can be influenced by human interventions.
- Vital tool when trying to scale understanding from the organism to the globe.
Functional ecology attributes? (4)
- Focuses on the roles/functions that species play in the community or ecosystem in which they occur.
- Concerned with the physiological, anatomical life history characteristics of the species.
- Represents the true crossroads between ecological patterns & the processes and mechanisms that underlie them.
- Makes sense of the biodiversity in nature by organising it into meaning groups.
4 concepts spoken about in functional ecology?
- Resource allocation.
- Trade-offs.
- Functional traits & Functional types.
- Life history strategy schemes.
Resource allocation attributes? (4)
- Organisms need to persist, grow & reproduce to be successful.
- They also need to cope with stressful environmental conditions, disturbances & competition from other organisms.
- Therefore, they need to balance the allocation of resources to: maintenance, growth & reproduction.
- Involves trade-offs to do so.
What do organisms need to balance the allocation of resources to? (3)
- Maintenance (defence & storage).
- Growth.
- Reproduction.
Scenario of resource allocation trade-offs? (2)
Resources are limited:
- If a plant puts its resources into growing leaves, then it can’t grow its roots.
- It can grow faster, but could die if the surface soil water runs out.
What is the goal of resource allocation?
To balance investments within a specific environment in order to maximise fitness.
Fitness?
= the ability to survive & reproduce.
If a plant is in a desert environment, what will it invest in and trade-off?
If a plant is in a rainforest environment, what will it invest in and trade-off?
Evidence of Resource allocation? (2)
- Importance of root traits in seedlings of tropical tree species.
- Resilient livestock.
Explain “Importance of root traits in seedlings of tropical tree species”? (3)
- In dry savanna (dry environment), the seedlings invested in maintenance of roots over growth & reproduction.
- In humid & transition environments, seedlings invested in both growth & reproduction.
- In dry & moist forests (wet environments), seedlings invested in growth of leaves.
Explain “Resilient livestock’? (3)
- Female cows (mothers) had to trade-off between milk production for their calves & their own survival.
- Mothers that chose to invest in survival produced less milk, which might have compromised the survivability of their calves.
- Mothers that chose to invest in milk production (reproduction), had a lower chance of survival.
Things to note about resource allocation? (4)
- At infant/seedling stages = growth is invested (then maintenance & no reproduction).
- At juvenile/mid stages = growth is invested, then maintenance & bit of reproduction.
- At adult stages = reproduction is invested, then maintenance & little growth.
- As organism grows, growth decreases (in terms of prioritization), maintenance steadily increases & reproduction increases (all in terms of prioritization).
Trade-offs attributes? (4)
- Imposed by constrainst of physiology, energetics & the physical and biotic environment.
- Key to understanding life history strategies.
- Universal due to finite resources as,
- Resource allocation to one function takes resources away from other functions.
Egs of trade-offs? (3)
- High photosynthetic rates vs Water use efficiency.
- High reproductive output (number of seeds) vs High reproductive effort (seed size).
- High investment in structure & defence (dense wood) vs High photosynthetic rates.
What is being traded off in Graph 1 of Resource allocation trade-offs?
- x-axis = Number of flowers per plant in year 1.
- y-axis = Plant size in year 2.
- Scatterplot with dots everywhere but mostly clustered in the middle & high up on the y-axis.
- Therefore,…?
What is being traded off in Graph 2 of Resource allocation trade-offs?
- x-axis = Age at first reproduction.
- y-axis = Median lifespan.
- Increasing linear graph.
- Therefore,…?
What is being traded off in Graph 3 of Resource allocation trade-offs?
- x-axis = Body size.
- y-axis = Fertility rate.
- Decreasing linear graph.
- Therefore,…?
Resource allocation & Life history strategies attributes? (2)
- These resource allocation trade-offs constrain the types of organisms that can persist in a certain environment, but also can create a diversity of solutions to the same environmental problem.
- If an organism can survive in an environment, then this “life history strategy” is successful.
Egs of resource allocation & life history strategies? (2)
- Global spectrum of plant form/growth form (shrubs, trees, grasses, etc) & function.
- Continental spectrum of the form & intensity of large mammal herbivory in Africa.
