Biodiversity Flashcards
Define Biodiversity
Biodiversity is the variety of plant and animal life and their interactions in the world, as well as the variety of ecosystems. It is the diversity of species and ecosystems
What is species richness?
It is the number of species present within an ecosystem, the more different species there are the greater the richness.
What is species evenness?
It is the evenness of the number of organisms between different species.
What does SDI show?
SDI is a measure of diversity, the number calculated shows the chance that two randomly selected organisms within a sample will be different species.
Explain percentage cover and frequency
Percentage cover is the percent of an area that a species is covering and frequency is the probability that species will be found in a quadrat.
What are the threats to biodiversity?
-Habitat loss and destruction
-Alterations in ecosystem composition (population dynamics)
-Introduced species
-Over-exploitation
-Pollution and contamination
-Global climate change
What are the different species interactions?
-Predation
-Symbiosis
-Competition
-Disease
Explain predation
Predation is the process by which one species feeds on another for survival.
Explain the 4 type of symbiotic relationships with an example
-Mutualism, both species benefit, zooxanthallae and corals
-Commensalism, one benefits the other is unaffected, sharks and remora
-Parasitism, one benefits the other is negatively affected, round worm and fish
-amensalism, one is unaffected the other is negatively affected, fish and algal blooms
Explain competition
Competition is the process by which species compete for resources such as food and space
Explain disease
-parasites, lives in or on a host for food
-Pathogen, causes disease
-Host, harbours smaller organisms
-Vector, DNA molecule
What are some abiotic factors?
-Climate
-Substrate
-Size/depth of the area
What are spatial and temporal scales?
Spatial scales are the size of land area being studied
Temporal scales are the time period over which an ecosystem is studied
How do environmental factors affect the distribution and abundance of species in an ecosystem?
Different species will have different tolerances to factors such as climate which may increase or decrease their population sizes and where in the ecosystem they are found. Availability of resources such as food, water and shelter will also impact the carrying capacity of species and where they are found.
