Topic 10.1 The Nature of Ecosystems Flashcards
Community
The organisms of all species that live in a habitat at one time (interdependent)
Abiotic factors: Climatic factors
-Wind speed
-Humidity
-Light intensity
Abiotic factors: Edaphic factors (soil)
-pH
-Oxygen concentration
-Nitrate concentration
-Salinity
Abiotic factors: Topographic factors (shape of landscape)
-Water speed
-Depth
Biotic factors
-Competition
-Predation
-Disease
-Symbiosis:
-mutualism
-parasitism
Ecosystem
Self contained unit make up of the biotic and abiotic factors in an area
(Ecosystem = Community + Habitat)
Biome
An area classified according to the species that live in that location
Population
A group of individuals of the same species in a habitat
Environment
All the factors in a habitat which affect an organism
(These may be biotic or abiotic)
Producer
The first organism in a food chain, an autotroph capable of manufacturing organic molecules normally by photosynthesis
Consumer
Organisms that feed off of other organisms
Decomposer
An organism whose ecological function involves the recycling of nutrients by performing the natural process of decomposition as it feeds on decaying organisms
Biodiversity
The variation that exists within and between all forms of life
Population
Groups of the same species in one area
Guttation
Water from xylem seeps out of edges and tip of leaf root due to pressure
Succession
The process of a community changing over time.
(It is heavily influenced by the conditions in the environment)
Primary succession
Plants grow where no plants have grown before (begins with bare rock)
Secondary succession
Plants grow where a population has previously been but has been destroyed (eg. forest fire)
Order of succession
Bare rock –> Pioneer species (opportunist) –> Decomposition –> Grasses grow –> Nutrients in soil allow shrubs to grow –> Increase in soil depth allows trees to grow
Opportunist
Take advantage of the bare rock to grow
Climax community
A self-sustaining community ………?
Plagioclamax
Climatic climax
Natural catastrophe
Volcanic eruption, fires, blowouts of sand dunes
Human deconstruction
Burning of forests, drainage of marshes
Human management
Ploughing, grazing
Why does diversity increase during succession?
As soil content changes allows more nutrients to be available, this in turn creates an environment which can support more diverse species.
Two main types of sampling
-Random sampling
-Systematic sampling
Biotic factors: Predation
A predator will reduce the numbers of prey species. As prey population increases, there is more food for the predators, so predator population increases too.
The predators will increase to the point where they are eating more than those being produced so the numbers of prey fall in turn reducing the numbers of predators as there is less food.
Biotic factors: Finding a mate
The likelihood of finding a mate will help determine the organisms that are found in any habitat. A single individual of a species in an area doesn’t mean that species lives in the habitat. Availability of mates has a big effect on the abundance of animals in an area.
Biotic factors: Territory
A territory is an area held and defended by an animal (or group) against other organisms. Territories have different functions for different animals, but they are almost always used in some way to make sure that a breeding pair has sufficient resources to raise young.
Biotic factors: Disease
Diseased animals will be weakened and often don’t reproduce successfully. Sick predators cannot hunt well. Some disease are very infectious and can be spread without direct contact (eg. avian bird flu).
Negative feedback loop (example)
Rabbits increase –> lynx increase (more food) –> rabbits decrease (more are eaten) –> lynx decrease (less rabbits to eat) loops back around
Ecological niche
If a habitat is a species ‘address’ then the niche is the habitat and it’s ‘profession’.
Competitive exclusion principle
Two species or population can’t occupy the same niche: one will consistently out complete the other.
Density dependent limiting factors
Factors that depend on population size
Density independent limiting factors
Affect populations in a similar way, independent of population size.
Density dependent limiting factors: Examples
-Competition
-Food
-Predation
-Disease
-Parasitism
Density independent limiting factors: Example
-Wildfire
-Hurricane
-Deforestation
-Volcanic eruption
-Draught
Sexual dimorphism
Females and males look different
Sexual selection
Females select a mate that beneficial to them
How do humans impact the ecosystem
-Illegal wildlife trade
-Overfishing
-Population (growth/consumption)
-Pollution
-Destruction of natural habitat
-Climate change
How to reduce the impact on ecosystem
-Consume and responsibly
-Eat meat and diary responsibly
-Reduce food waste
-Education
Valid definition
Can use the results as they’re related to your study/properly design.
Reliable definition
Replicable, other scientists can repeat them.
Biased definition
Influenced in some way.
Correlation definition
They have a relationship, but don’t directly affect each other.
Causation definition
Directly affect each other.
Peer review: Who carries out peer reviews?
-Experts in the same field of work
-Colleagues
-Subject specialists
Peer review: Why do scientists need to communicate their findings?
-Validity and reliability
-Get recognition
-Help other scientists
Peer review: What is the process of peer reviews?
-Draft articles written by author
-Copies are sent to experts
-Reviews can ask questions
-Reviewers make recommendations to the editor on whether to accept or reject
Peer review: Advantages
-Recognition
-Reliable findings
Peer review: Disadvantages
-Time consuming
-Small amounts of work is published
-Incorrect details can be still published
Climate
Climate is the average weather pattern is an area over many years. Rising temperatures affect weather patterns and can also cause long term changes.
This has many affects including wildfires, droughts, extreme weather events, soil changes.
These impact the migration, biodiversity, distribution.
What changes can be made to fix climate change?
-Reduce meat consumption/farming
-Reduce the amount of cars/fuel used
-Locally sourced food
-Tax carbon emissions
-Legislate against unsustainable practices
-Hosepipe bans
Farming
?
