chap 4 Flashcards
A major reason why organisms do not spread everywhere is that each species and each individual organism of a species has a particular range of ______ to variations in chemical and physical factors in its environment such as temperature
tolerance
Limiting factors in terrestrial ecosystem can include:
temperature, water, soil, nutrients, and light
______ states that the existence, abundance and distribution of a species in an ecosystem are determined by whether the levels of one or more physical or chemical factors fall above or below the levels tolerated by the species.
Law of tolerance
_____ states that too much or too little of any abiotic factor can limit or prevent growth of a population of a species in an ecosystem, even if all factors are at or near he optimum range of tolerance for the species.
Limiting factor principle or Principle of limiting factor
refers to the species way of life or functional role in an ecosystem. Involves everything that affects its survival and reproduction.
Ecological Niche
Species’ niche:
a. tolerance for various physical and chemical conditions
b. type of resources
c. how it interacts with other living and non-living components
d. role it plays in the energy flow
the actual location where a species lives. Ecologists often say that a niche is like a species’ ______, whereas ____ is like its ______
Habitat, occupation, address
Types of ecological niche:
a. fundamental niche
b. realized niche
the full potential range of conditions and resources a species could theoretically use if there were no direct competition from other species.
Fundamental niche
parts of the fundamental niche of a species that are actually used by that species
realized niche
have broad niches and can live in many different places, eat a variety of foods, and tolerate a wide range of environmental conditions
generalist species
Broad classification of species according to their niches:
i. generalist species
ii. specialist species
have narrow niches and may be able to live in only one type of habitat, tolerate only a narrow range of climatic and other environmental conditions, or use only one or few types of food.
specialist species
general types of species according to the roles they have in ecosystems:
i. native or endemic species
ii. nonnative, alien, or exotic species
iii. indicator species
iv. keystone species
species that normally live and thrive in a particular ecosystem
native or endemic species
species that migrate into an ecosystem or are deliberately or accidentally introduced into an ecosystem by humans
nonnative, alien, or exotic species
species that serves as early warnings that a community or ecosystem is being degraded
indicator species
species that play roles affecting many organism in an ecosystem
keystone species
Three basic types of interactions among species:
- competition
- predation
- symbiosis
occurs when two or ore organisms compete for food, space, or other limited resources.
competition
two or more organisms of a SINGLE SPECIES trying to use the same limited resources
intraspecific competition
members of two or more species trying to use the same limited resources
interspecific competition
situation in which member of one species feed directly on all or part of a living organism of another species (the prey).
predation
the prey may or may not die from the interaction (T/F)
okay fine, true
a long-lasting relationship in which species live together in an intimate association
symbiosis
types of sybmiosis
i. parasitism
ii. parasitoidism
iii. mutualism
iv. commensalism
v. amensalism
occurs when one species feeds on part of another organism by living on or in the host for a significant potion of the host’s life
Parasitism
live inside their host
endoparasites
attach themselves to the outside of their host
ectoparasites
small number of parasites that routinely kill their hosts as part of their life cycle
parasitoidism
two species involved in a symbiotic relationship interact in ways that benefit both
mutualism
relationship is essential for the survival of both populations
obligatory mutualism
relationship is not essential for the survival of either population, e.g., insects involve in seed dispersal and pollination
nonobligatory mutualism
a symbiotic interaction that benefits one species but neither harms nor helps the other species much, if at all
commensalism
is an ecological interaction between two species, but in this association among organisms of two different species, one is destroyed or inhibited, and the other remains unaffected.
amensalism
