Ecology Lesson 1 Flashcards
What is ecology?
Ecology is the science of how organisms interact with each other and with their environment and how they are shaped by it. It includes both biotic and abiotic components. A discipline that’s quite modern. A term coined by Ernst Haeckel in the 19th century only 100 to 150 years ago.
Mutualism
Both parties benefit from the relationship.
What would happen if we didn’t have ecosystems?
We would be extinct. Animals and plants support all human life on earth. They support fisheries and other economic benefits.
We need to ensure our ecosystems are what?
Sustainable. So the biosphere can still function the same way it does now (stop the effects of climate change).
Modern ecology uses what approaches?
Observational studies
Experiments (e.g. experimental ponds).
Data analysis & statistical modelling of patterns.
Remote-sensing, drones, camera traps.
Observational studies
Looking at natural systems and recording information.
Experiments
Understand the mechanisms and change one thing and see how they change. It’s what makes it different than natural history.
Data analysis & statistical modelling of patterns
Understanding what’s happening and what will happen in the future.
Remote-sensing, drones, camera traps
Remote sensing: all collect data
Drones: mapping
Camera traps: limit human presence and a more technical approach.
Ecology tries to understand what?
The why and how of life and how it will change in the future.
Ecologists in action
A lot of work is collecting data. ie. using satellites to see the number of vessels and from there can infer that more fish are there.
Indigenous and traditional ecological knowledge?
People have been observing the environment for a while and citizens also collect data. ie. listening to birds.
Ecologists often examine what?
Distribution and Abundance
Distribution
Limits to distribution (why isn’t everything everywhere, why restricted to one place. They can’t be perfectly adapted, because when one adapts to one environment they would be less adapted to another).
Changing distributions (Often humans do this).
Abundance
Changes in abundance (growing and shrinking).
Are populations growing and shrinking (how predators and prey interact).
The importance of ecology in your world?
Climate change, mass extinction, and biodiversity loss. (It’s important for understanding how we can continue to ensure a sustainable biosphere.
Climate Change
Impacts humans, animals, environments. Happening very quickly, it changes ecosystem (ie. coral reefs changing). Distribution of plants and animals. Disease transmission (ie. Lyme and malaria).
Mass extinction
Species disappearing because of humans.
Biodiversity loss
Forest disappearing changing from more natural systems to agricultural and urban systems.
Types of problems addressed by ecology?
Conservation and biodiversity Environmental issues
Wildlife & resource management
Pest control
Human health
Conservation and biodiversity
Evaluate effectiveness of conservation strategies, trying to preserve life.
Do marine protected areas work? (is the population having an impact).
Environmental issues
Evaluate consequences of human activities.
What effect is climate change
having on biodiversity? (ie. fishing and hunting)
Wildlife & resource management
Evaluate effectiveness of management strategies.
When does fishing become
overfishing? (when does it become unsustainable).
Pest control
Strategies for reducing crop losses.
Why do some insects get out of
control? What can we do to reduce it and stop insects. How to use natural predators to limit these impacts.
Human health
How are diseases spread through animals? (zoonotic disease).
What are the most important animal vectors for disease? What is the role of climate? And how will climate change affect pathogen spread? See how these animals are moving and how it impacts humans. 75% of diseases are zoonotic.
Animal vectors
Aminals that carry the disease.
Levels of ecological study
Organism, population, community, ecosystem, landscape, and global.
What’s technically the first level of ecosystem?
Genetics and how genetics change and pose a risk to an organism.
Organism
How organisms adapt to environment (Through organs they have and use). Why they interact with certain things and how it impacts their lifespan.
Population
Same species. A group of them in the same area. A species can have many populations. Why dies it increase and decrease.
Community
Multiple species interacting. Can have positive or negative interactions. ie. all species in a coral reef and how they interact.
Ecosystem
Organism and abiotic environment. How energy flows through it. How the nutrient cycle and climate impact communities.
Landscape/ Seascape
Connected ecosystems. Connected by organisms moving between them taking energy and nutrients between them. ie. mountain and lake connected by a river.
Global ecology
The biosphere. All life on earth.
Biome
A habitat that covers a large part of the earth. Terrestrial biome defined by its dominant vegetation. They are not separate, more like a continuum.
Distribution of terrestrial biomes
Dividing the world with different types of plants (ie. why is there different things in different biomes).
Tundra
In Canada and Russia (north). They are treeless with mostly shrubs and harty plants (to be resilient to the climate). Need to survive the frost (like frozen ground), and they have different root systems.
Northern coniferous forest
In Canada, Russia, N.S.. They have evergreen (trees that have leaves all year) the leaves are needles. The needles minis water loss shaped that way, and they have a waxy covering. This is because summers are short and strong season signals. Relationship between rainfall and vegetation type. By not dropping leaves they don’t expand nutrients.
Temperate broadleaf forest
They have broad leaves. They are large and lose a lot of water, so it makes sense to lose them over the winter(to energetically costly to keep them all year). Deciduous (drop leaves in fall). The colour change in fall caused by retracting chlorophyll and nutrients from the leaves. Regrow leaves in the spring.
Tropical Forest
Have evergreen with broad leaves that retain all year. No seasons, lots of nutrients, sunlights all year, and photosynthesis all year. Very diverse animals and trees. Rainforest that’s humid with a rich biome.
Distribution correlated with latitude?
How close to poles. Hypothesis: climate drives the observed patterns in biomes. It’s why no one type can dominate earth.
What drive transitions among biome types?
Temperature and precipitation.
Savanna
Has grasses with a few trees. Patches of tress, not continuous. It has dry and wet seasons and always hot. Very interesting animals live here.
Why are there grasses and not trees in the savanna?
But grasses can handle a drought and lots of rain. They are rapid responding, and distrubance.
Disturbance
An event that removes individuals
from a population. It alters the equilibrium of the ecosystem.
Disturbances in the savanna?
Large herbivore grazers (like elephant and wildebeest), as they eat trees. Also Fire from humans and natural. Grass can grow quickly after fire then trees. Without these the savanna would be woodland. It makes grass the better competitor.
What drive transition from forested to non-forested biomes?
Precipitation and disturbance. ie. Tropical forest to tropical savanna. and temperate broadleaf forest to temperate grassland.
Temperate grasslands
Drier and warm/cold.
Deserts
Wide range of temperatures. Antartica is a desert. Hot days and cold nights. Unique ecosystems with unique evolutionary heritage of organisms that have adapted to live in them. Sometimes have a big burst of rainfall.
Do biomes overlap?
Yes.
Two main things that structure vegetation?
Temp and rainfall.
Coyote distributions
Over 100 years it doubled range. Occupied grasslands and semi-desert.
What limits distributions?
Dispersal, abiotic factors, and biotic factors.
Dispersal
Organism didn’t get there, and can’t there. ie. mice can’t travel far. Also islands are very isolated, so the animals there are very unique.
Endemics
Animals that are only found on islands.
Abiotic factors
How climate influences it. Temperature moisture. Salinity and oxygen in oceans. Can move there but can’t persist there.
Biotic factors
Resources (food)
Predation
Competition
Disease
Why did coyote distribution change
Wolf distribution changed and European settlement. (resources, predation, and competition).
Wolf distribution changed
The grey wolf is bigger and stronger than the coyote, so it would steak all the food resources. But then the wolf moved more north due to humans hunting them. This extermination of wolves made eastward expansion easier for coyote.
European settlement
Agriculture led to forest removal.
Abundant rodents and other small prey. Habitat began to resemble grassland and coyotes do well in this so they become a stronger competitor.
What’s a population
A group of individuals of a single
species living in the same area.
Potential to interact: Mate, Compete for food, Socialize. ie. bighorn sheep on Ram Mountain, AB.
Interspecific
Between species
Intraspecific
Within species.
Population dynamics
Population size and density. Abundance and density change over time.
Population size
Number of individuals. ie. about 45 sheep in Ram Mountain.
Density
Number of individuals per unit area. ie. 1.25 sheep per km2. Count over area.
Desert locust
It can cut through vegetation. Swings in population sizes, they are kms ling and quite rare, it happens every decade. They are like large grasshoppers. Herbivores: eat own weight each day. They eat through agriculture so it can be a problem. Life cycle: ~ 4 months, Egg (100/female), Juvenile (hopper), Adult. It’s how population can grow very quickly.
Where are deserts and what are they?
Between 20 and 30 intermediate latitudes. It’s dry, hot or cold, pulses of rain. Very specialized ecosystem, low productivity.
Sun hitting the earth
At equator the sun hits directly and concentration, so a lot of heat and energy very intense. At the poles the sun hits at an angle, the sun is more scattered, so the amount of energy drops because it’s spread over larger area.
How are deserts dry?
Warm air rises up, and as it does it gets cool which holds less moisture. Then when it’s releases it, it rains. Then the air drys out and pushed away from the equator. Then dry air coming down absorbed moisture making it dry then it is recirculated. These are could Hadley cells.
Food and agriculture organization of the United Nations
Desert locusts are on it because they pose a threat. It tracks the swarms and shows regions at risks. Varys month to month.
Outbreaks
Rapid increase in population abundance because something allowed the population to grow rapidly and something also stopped it. Very spaced out, over decades.
Exponential growth
Unlimited growth and Growth in unlimited environment. See often in bacteria and unrestricted areas also diseases.
Growth model equation
dN/dt = rN
dN/dt is the change in populations
N is the population size
r is the per capita growth rate (used to compare populations).
Positive r
population grows
Negative r
population declines then will go extinct.
r=0
no change in population size.
Larger r
faster growth
Smaller r
slower growth
4 rates that impact per capita growth rate?
Birth rate (+)
Death rate (-)
Immigration rate (+)
Emigration rate (-)
r= b-d+i-e
Closed population
Has no immigration or emigration. ie. some islands because it’s hard to get there.
r= b-d
b>d
population grows
b<d
population declines
b=d
population stays the same
For the same r, what will the population do?
A large population will grow more than a small population.
Open Population
Has migration, ie. a chain of islands.
Net per capita migration rate
Difference between immigration
and emigration rates. m=I-e. It can be positive, negative, and zero.
Cause of desert locusts outbreak?
Birth rate became much higher because of environmental change. When it rains, more vegetation, so more food (meaning females are lay more eggs and in better conditions so more hoppers survive, all hatch and move together causing clumping on groups together, then crowding, gregarization because the hair on legs of them brush together and cause swarms and become social.
Spatial arrangement of individuals
Uniform (very rare), random, and clumped (in groups for many reasons like defence from predators, for mating, social reactions).
Gregartization changes desert locusts how?
Low density: pale green and fly alone at night.
High density: strong colours and fly in swarms in the day.
Gregarization
Change from population of solitary forms to population of gregarious forms.
Gregarization in desert locusts
Mechanical stimulation on legs releases Hormones -> seratonin.
Causing behaviour changes in hours.
Colour change at moult.
Adult swarms
Increased mobility and move across continent. Track wind patterns well. Climate can predict where it will happen. Places either more rainfall.
What ends the outbreak?
When d>b. The environment changes again. Rains end – no new vegetation. Locusts have eaten everything, so no more food so higher mortality. No longer crowded: revert to solitary form.C
Control efforts
Primarily pesticide spraying. For the high population can guess where it will occur.
