APES chapter 5 biodiversity, species interactions and population control
reproductive patterns
can either be frequently or not as frequently. frequently and produces 1-2 or not as frequent and produces 5-100., (ex) elephants and humans vs sea horses and spiders
interspecific competition
competition between members of different species - for limited resources - ecological niche for exploiting resources - some Niches overlap
coevolution
interacts over a long period of time example: bats and moths: echolocation of bats and sensitive hearing of moths
5 major ways species can interact
interspecific competition predation parasitism mutualism commensalism
natural ecological restoration
primary/secondary succession, various forms of life adapt to changes in environmental conditions
how do communities and ecosystems respond to changing environmental conditions
the structure and species composition of communities and ecosystems change in response to changing environmental conditions through a process called ecological succession
limiting factor principle
too much or too little of any physical or chemical factor can limit or prevent growth of a population, even if all other factors are at or near the optimal range of tolerance. ex precipitation: identifies a biome nutrients: no more nutrients sunlight: if no sunlight
population change that occurs in nature
- stable - irruptive: population surge, followed by crash - cyclic fluctuations, boom-and-bust cycles: top-down population regulation or bottom-up population regulation - irregular
predation
An interaction in which one organism kills another for food. Because of limited resources most consumers feed on live organisms of other species can be captured by walking, swimming, flying, pursuit and ambush, camouflage, and chemical warfare
facilitation
An interaction in which one species has a positive effect on the survival and reproduction of another species without the intimate association of a symbiosis
tolerance
In environmental science, the law of tolerance says that there is a limit to the amount of adaptation to the environment that any species is able to do. So, the environmental conditions around a species can vary somewhat, but only up to a point, before the species starts to have difficulty surviving.
population size
Is governed by birth, deaths, immigration and emigration population change = (birth + immigration) - (deaths+emigration)
carrying capacity (K)
Maximum population a given habitat can sustain
prey may avoid capture by
Run, swim, fly Protection: shells, bark, thorns Camouflage Chemical warfare Warning coloration Mimicry Deceptive looks Deceptive behavior
primary succession
STARTS FROM SCRATCH An ecological succession that begins in an area where no biotic community previously existed no soil in terrestrial system no bottom sediment in an aquatic system takes hundreds to thousands of years need to build up soils/ sediments to provide necessary nutrients tend to increase biodiversity increase species richness and interactions among species
2 viewpoints of succession
traditional view: Balance of nature and a climax community current view: ever-changing mosaic of patches of vegetation, mature late-succession ecosystems, state of continual disturbance and change
range tolerance
variation in physical and chemical environment
resource partitioning
ways for some species to evolve ways to share resources - using only parts of the resource - using at different times - using in different ways
core case study: Southern sea otters: are they back from the brink of extinction
- Habitat - Hunted: since the early 1900s - PARTIAL recovery - Why care about sea otters?: ethics, tourism dollars and they are a KEYSTONE species
3 big ideas
1. certain interactions among species affect their use of resources and their population sizes 2. there are always limits to population growth in nature 3. changes in environmental conditions cause communities and ecosystems to gradually alter their species composition and population sizes (ecological succession)
age structure
1. pre reproductive age (biggest population) 2. reproductive age 3. post reproductive age
population clumps
1. species tend to cluster where resources are AVAILABLE 2. groups have a better chance of finding clumped resources 3. protects some animals from predators 4. packs allow some to get prey
commensalism
A relationship between two organisms in which one organism benefits and the other is unaffected In some interactions, one species benefits and the other is not harmed examples: epiphytes and birds nesting on trees
parasitism
A relationship between two organisms of different species where one benefits and the other is harmed Some species feed off other species by living in or on them usually smaller than the host, RARELY kills the host and may lead to coevolution
mutualism
A relationship between two species in which both species benefit In some interactions, Both species benefit nutrition and protection relationship gut inhabitant mutualism not cooperation: it's mutual exploitation
secondary succession
DOES NOT START FROM SCRATCH Succession following a disturbance that destroys a community without destroying the soil some soil remains in a terrestrial system some bottom sediment remains in an aquatic system ecosystem has been - disturbed -removed - destroyed tend to increase biodiversity increase species richness and interactions among species
inhibition
During a succession, modification of the environment by a species in such a way as to reduce the suitability of that environment for a species that would otherwise become established in a later seral stage
how do species interact
Five types of species interactions - competition: species fight - Predation: species fight other species for food - Parasitism: species feed off of other species for energy and food - mutualism: harmony - commensalism: one benefits and the other derives neither benefit nor harm.
resilience
ability of a living system to be restored through secondary succession after a moderate disturbance
inertia, presistance
ability of a living system to survive moderate disturbances
environmental resistance
all factors that act to limit the growth of a population
J-curve
exponential growth starts slowly, then accelerates to carrying capacity when meets environmental resistance
How do species replace on another in ecological succession
facilitation inhibition tolerance
population
group of INTERBREEDING individuals of the same species can live together in clumps or patches population distribution: clumping, uniform dispersion and random dispersion
living systems are sustained through constant change
inertia, persistence resilience
ways that predator and prey interactions can drive each other's evolution
intense natural selection pressures between predator and prey population can use COEVOLUTION
Threats to Kelp forests
kelp forests: biologically diverse marine habitat threats include: sea urchins, pollution from water run-off, and global warming
density dependent factors
limiting factor that depends on population size - predation - parasitism - infectious disease - competition for resource
size of population controlled by
limiting factors ex: light, water, space, nutrients, exposure to too many competitors, predators, or infectious diseases
S-curve
logistic growth decreased population growth rate as population size reaches carrying capacity
What limits the growth of population
no population can continue to grow indefinitely because of limitations on resources and because of competition among species for those resources