Ecological Systems Flashcards
what is predation?
Predation involves the members of one species (predator) capturing and consuming members of another species.
how does a predator-prey relationship work?
In a predator-prey relationship, the population numbers of predator and prey are constantly fluctuating out of step with each other.
what is competition?
Competition is when organisms strive for the same resources at the same time in the same place.
intraspecific competition
competition that occurs between individuals of the same species for limited resources (ex. vulture)
interspecific competition
competition between individualsof different species that occupy the same habitat and rely on similar resources (ex. cheetah and lion competing for zebra)
what is symbiosis?
Symbiosis refers to types of close relationships between organisms of different species.
what is mutualism?
both organisms benefit
ex. coral polyps and zooxanthellae
what is commensalism?
between 2 different species in which one species benefits while the other is unaffected
ex. remora and shark
what is parasitism?
parasite lives on, or in, another (host)
the parasite benefits while the host suffers
ex. flatworms feeding on polyps
what is ammensalism?
A type of relationship in which one species is harmed, while the other is neither harmed nor doesn’t benefit.
what is altruism?
A type of relationship in which individuals within a particular species behave in such a way that the chance of survival of other members is increased while decreasing the chances of the individuals making the sacrifice.
abiotic factors
• Atmospheric gases
• Wind
• Fire
• Solar radiation
• Temperature
• Relative humidity
• Day length
• Aspect
• Soil water and chemistry
• Soil parent rock
• Salinity
• Wave action
biotic factors
• Humans
• Competitors
• Predators
• Parasites
what is equilibrium?
steady state of an ecosystem where all the organisms are in balance with each other and with their environment.
parameters used to measure changes in ecosystem
resistance
resillience
what is resistance?
ability of an ecosystem to remain at equilibrium in spite of disturbances
what is resillience?
speed at which an ecosystem recovers its equilibrium after a disturbance
relationship between biodiversity and dynamics
The greater the biodiversity of an ecosystem, the greater its resistance to disurbances and also the greater its resillience after disturbances. Such an ecosystem is more stable.
However, the nature of an ecosystem may change to such a degree that it loses its resillience altogether. This can lead to irreversible altering of the ecosystem.
what is ecosystem dynamics
the study of changes in ecosystem structure caused by changes in the environment or by internal forces
what determines ecosystem stability?
resistance to change, deterioration, or depletion
- the ability of an ecosystem to return to its original state after a disturbance
- the fluctuation of numbers with a balance being restored over time.
what is biodiversity?
the sum of all the different ecosystems on earth, the various species found in each, and the variable genotypes
what is genetic diversity?
Refers to the variety of combinations of genes found in organisms
relationship between genetic diversity and stability
With greater genetic diversity, there is more variations in physical characteristics, viability, productivity, resillience to stress adaptability to stress in the environment
With very little genetic variation, offspring have reduced chance of survival, with changes in the environment, since they may be susceptible
what is species diversity?
number and relative abundance of each species in a community.
what is richness?
the number of species
what is abundance?
the number of individuals of each species present
what is evenness?
similarities of the population sizes of each species present
what is disparity?
differences in form and structure, shape and morphology between species
what is species disparity?
how different the species are in terms of their morphology, form and structure
relationship between species disparity and stability of an ecosystem
The greater the species disparity, the more ecological niches can be occupied and the greater the number of interactions among the organisms in an ecosystem at different trophic levels. Hence, the more likely such an ecosystem is regarded as a stable one.
what is ecosystem diversity?
Refers to all of the unique and varied habitats, processes, as well as variations within individual ecosystems on the planet
examples of ecosystems
wetlands
reefs
savannahs
tropical rainforests
deserts
temperate forests
grasslands
what features does ecosystem diversity focus on?
Includes variation in ecological niches, trophic levels and ecological interactions among organisms
→ Examines how they affect each other, as well as the roles the ecosystems play on our planet (ex. Water cycle, formation of soils, etc.)
importance of maintaining diversity
To maintain the complexity of ecosystems so that they will be more stable
To ensure that our water resources are protected and that nutrients continue to be cycled in nature (ex.nitrogen)
Ensures that our soils are protected and that soil formation continues
Ensures that the breakdown of dead bodies to release nutrients occurs, as well as the removal of pollutants from the environment, helping to make the environment safe for all
Important to maintain the balance between gasses (ex. Oxygen and carbon dioxide)
Stabilization of climate since plants play an important role in reducing the greenhouse effect
For medical research into cures for the present and in the future
To maintain a food supply in the present and in the future
Humans are custodians of all life on our planet and we depend on the other species directly and indirectly; hence it is important that we ensure that biodiversity, in all its forms, is maintained
threats to biodiversity
Climate change → global warming
Clearing of vegetation on slopes → soil erosion, flooding, destruction of ecosystems and loss of biodiversity
Quarrying → loss of vegetation, permanent destruction of habitats and loss of biodiversity
Pollution (oil spills)
Introduction of exotic species → disrupts ecosystems, upsets the balance of numbers, and competing with native species for food resources, as well as introducing pathogens and pests which can destroy populations of species
Hunting of species indiscriminately/ out of season → disrupts ecosystems → endangers particular species → extinction
what is conversation?
the active preservation of the diversity of life by various means
types of conservation
in situ
ex situ
what is in situ conservation
Conservation of organisms in their natural habitat. They are maintained and efforts are made to ensure that populations recover if they were threatened
examples of in situ conservation
national reserves
national parks
advantages of in situ conservation
Less expensive to leave organisms in their natural habitats
The natural habitat and vegetation are not going to be disturbed
Organisms are not going to become tame or change their behavior
Organisms learn to cope with competition in situ and to interact with each other
More likely to mate and successfully reproduce in situ
Organisms are already adapted for survival in their natural environment
Organisms continue to evolve, enabling adaptation in a changing environment in situ]
disadvantages of in situ conservation
Cost of hiring game wardens and security to monitor and protect the natural habitat is very high
Size of area which has to be protected may be very large and difficult to patrol
Natural disasters may destroy entire ecosystems
Difficult to treat organisms affected by disease in a large area
how is a national park in situ conservation?
National parks ensure that organisms are in their natural environment. Visitors can enter for education, tourism recreation, inspiration so long as they do not pose a threat.
what is ex situ conservation?
This is the conservation/ preservation of genetic and species diversity away from thenatural habitat.
advantages of ex situ conservation
- Usually as a last resort when a population of a particular species has becomevery small or so endangered that extinction is considered inevitable withouttaking extreme measures.
- To conserve species of local importance and restore local ecosystems.
- For research into a range of organisms.
- For captive breeding programmes so that species can be reintroduced to thenatural habitat later on.
disadvantages of ex situ conservation
- Maintaining organisms in an artificial environment is expensive.
- Genetic diversity is not always improved with some methods (ex. Seed banks).
- Possible inbreeding can occur leading to less biodiversity.
- Organisms become adapted to captivity so it is difficult for them to survivewhen reintroduced to the natural environment.
what is a zoological garden?
Animals contained in enclosures or semi-open areas.
Places of education, conservation, observation of animal behaviour.
what are captive breeding programs?
Rare or endangered species are bred in captivity
Perhaps then the numbers are greatly reduced in the wild due to overfishing, huntingor diseases.
A few males and females are removed from the wild and taken to zoos where they arethen allowed to breed in captivity.
The numbers will increase over time anddescendants are released into their natural environment.
advantages of zoological gardens
- Increase public awareness about various species
- Carry out research on animals in captivity
- Animals can be treated for diseases while they are in captivity
- Captive breeding programs can prevent them from becoming extinct.
disadvantages of zoological gardens
- Ethical/ moral issues
- Some animals never reproduce in captivity
- Focus in many zoos is on larger, exotic species
- Small spaces prevent animals that require larger territories from functioningnormally
- The exact food requirements may not be met in a zoo
- Animals become tame, decreasing their survival when released into the wild
what are botanical gardens used for?
Cultivating plants for research, education, conservation, and recreation.
how do botanical gardens generate income?
through ecotourism and recreational activities
Name one ecological advantage of botanical gardens.
Natural selection can occur, ensuring survival of the fittest plants.
What is a limitation of botanical gardens?
Limited gene flow due to small population sizes of cultivated plants.
what is the purpose of seed banks?
To store seeds under controlled conditions for long-term conservation and future use.
what conditions are necessary for seed storage?
Low temperatures (10–20°C) and low humidity (5–10%).
define orthodox seeds and provide examples
Seeds that remain viable for long periods, e.g., peas, corn, and tomatoes.
define recalcitrant seeds and provide examples
Seeds that do not remain viable after extended storage, e.g., mango, avocado, and coconut.
what is a major advantage of seed banks?
Genetic material can be used to restore biodiversity after natural disasters.
what is a drawback of seedbanks?
Not all plants produce seeds suitable for storage, and periodic viability tests are required.
what is the role of human sperm banks?
To store sperm for individuals facing fertility issues or hereditary diseases.
name one avantage of human sperm banks
Safe effective method of ensuring continuation of human species
cost is not usually prohibitive
sperm are not damaged by freezing
what is a disadvantage of human sperm banks?
potential risk of incest
risk of infection and genetic disease
controversy
age issues for old and very young donors
why are embryo banks important to humans?
They allow storage of extra embryos for future use, reducing IVF costs.
what is a conservation use of animal embryo bank?
To preserve genetic material and ensure biodiversity of threatened species.
what is a conservation use of animal embryo bank?
To preserve genetic material and ensure biodiversity of threatened species.
what is a key limitation of embryo banks?
High costs associated with extraction, storage, and freezing.
what is the intrinsic value of biodiversity?
The inherent worth of all life forms, independent of their usefulness to humans
examples of direct values of biodiversity
Food (e.g., honey, fish) and medicine (e.g., tree bark for antibiotics).
what is one cultural benefit of biodiversity?
Many cultures revere and worship nature, promoting conservation efforts.
what does the ‘diversity promotes stability’ viewpoint suggest?
Ecosystems with greater species diversity are more resistant to disturbances.
name one experiment supporting diversity - stability
David Tillman’s study found diverse plant communities more resistant to drought.
what does the opposing viewpoint on stability argue?
Ecosystem stability provides a foundation for diversity, but diversity does not guarantee stability.
name a mathematical model opposing diversity-stability
Robert May’s models showed that diversity establishes ecosystem dynamics but does not always lead to stability.
what conservation efforts are happening in Belize?
A rainforest reserve jointly managed by the government and local healers.
what is an example of coral reef conservation in the Caribbean?
Coral reef restoration projects funded by the Global Environment Facility.
how are invasive spiecies being managed in the caribbean?
By promoting their use as food, e.g., lionfish on restaurant menus.
