Download Ecosystem Interactions, energy and dynamics

Ecosystem Interactions,
energy and dynamics
Headwaters Science Institute
Ecology
Ecology is a science.
What does that mean?
What do Ecologists do?
Key Terms
• Species
• Population
• Community
• Ecosystem
Subfields of Ecology
 Organismal Ecology
 Population Ecology
 Community Ecology
 Ecosystem Ecology
 Landscape Ecology
Ecosystem Ecology
 Ecosystems Ecology is the study of the interactions
between organisms, with each other, and with their
environment.
 Why are interactions between organisms important?
 Why do organisms usually interact?
Food Chain
 primary (1o) producers
 primary (1o) consumers
 secondary (2o) consumers
 tertiary (3o) consumers
 quaternary (4o) consumers
 Decomposers
Give an example of each.
Niche
 What is a Niche?
 What is the niche of a fox?
 Can you describe other Niches?
Predator-Prey Interactions
 What is predation?
 Host-parasite
 Herbivore-Plant
 Carnivore
 Give an example of each
 Why are these relationships important in ecosystems?
 How do you think the population on one of the two
affects the other?
Factors that Promote
Population Stability
 What things can keep populations balanced between
predators and their prey?
 What happens when the deer population becomes large?
 What happens whens if the fox overeat the hares in one
area? Do you think they can ever eat all of them?
 What type of defenses to prey evolve?
Predators and Evolution
 Why is predation an important evolutionary force?
 What does natural selection favor in a predator? Prey?
 Give an example of an evolutionary arms race.
 Toxic Newts and Garter snakes
 The garter has grown to be resistant to the toxins of the
newt and the newt continues to become more poisonous.
Ecosystem Interactions
 Between all different types of Organisms
 Types of Interactions





Neutral: 0 0
Mutualism: + +
Commensalism:+ 0
Parasitism and Predator/Prey + Competition - -
+ represents a benefit for one of the organisms
- represents a negative interaction for one of the organisms
0 represents a neutral interaction for one of the organisms
Competitive Interactions
 Inter vs Intra specific competition
 What do species compete over?
 What can happen when a new species is introduced to
an environment?
Predator/Prey
 Give an example of a Predator/Prey relationship
 Is there anything that eats the predator?
 What happens if the population of one of the animals
changes drastically?
 Can animals change foraging behavior as a reaction to
predators close by?
 Hypothesis: Animals will move to feed in protected area
when predators are nearby.
Cardinals and Hawks
 Cardinals prefer sunflower seeds to standard bird feed
 Prefer to forage near cover than in open, but will
choose sunflower seeds in open to standard feed in
cover
 When predator calls are played they prefer to feed on
lower quality food near cover
-Stanback 2010
Host-Parasite
 What type of interaction is a host parasite relationship?
 Do parasites usually kill their host?
 Ecotoparsite: lives on the outside
 Endoparasite: Lives on the inside
Host-Parasite
Dwarf Mistletoe: Arceuthobium abietinum on a Red Fir
Dwarf Mistletoe and Conifers
 Dwarf mistletoe is a parasitic plant
 Infects conifer trees
 Create brooms on the tree
 Species specific parasite
 Mimic trees growth hormones to get water and nutrients
 Live a long time before they kill a tree
 Seeds
 Dispersed in the fall
 launch via hydrostatic pressure (up to 50mph)
 Travel about 30 ft
Mutualism
 What is a mutualistic relationship?
 Give an example.
Commensalism
 What is commensalism
 Give an example?
 What is the difference between commensalism and
mutualism? Parasitism?
Territories
 Within Species competition for resources
 Food
 Shelter
 How do resources affect territory size of an animal?
Hypothesis
Animals adjust territory size to the density of the critical
resource (usually food) so the territory contains enough to
satisfy their requirements
Competition and territories
Caddisflies
• Territorial insect
• Eat algae
• More Algae =smaller territory
• Less Algae=larger territory
Territory Size
-Hart 1985
Caddisflies expand their territory after food
decreases
-Indicates they are capable of foraging in larger
territories
-Why don’t they defend a larger territory?
What do you know?
 What questions can we ask about ecosystem ecology?