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