conditions and resources Flashcards
what is needed to know and understand the distribution and abundance of a species
1) history
2) environmental conditins
3) resources needed
4) life histories and pop dynamics
5) interactions within their own and other species
what are conditions
abiotic environmental factors which influence the functioning of an organsism which cant be consumed or used up
true of false: conditions can be modified by the presence of other organisms
true
define optimum conditions
conditions in which the most offspring are produced however an organism can survive under a range of conditions
what did odum 1955 say about limiting conditions or factors
any condition which approaches or exceeds the limits of tolerance is said to be a limiting conditions or factor
give some examples of conditions
temperature
soil Ph
physical forces such as wind or currents
enviro pollution
global change
outline how the conditions of temperature can influence organisms
1) metabolism = rate of oxygen consumption increases
2) growth = linear relationship between growth rate and temperature
3) development and size= linear relartionship between developmental rate and temperature
why might and increase in temperature lead to a decline in final size
development increases more rapidly with temp than growth rate
why is it important to know the effects of temperature in ecology
1) understand the role in seasonal, annual and geographic variations in productivity
2) know the effects of a rise in global temperature
what is the difference between endotherms and ectotherms
endo= regulate temp by the production of heat within their own bodies
ecto= rely on external heat sources
what can low temps cause
chilling can damage membranes and permeability
freezing can affect osmoregulation
give some examples of where temperature can act as a stimulus
1) artic alpine plants- freezing can stimulate germination
2) egg laying can be stimulated by temp
3) stimulate breeding
how can temperature interact and affect species
1) humidity= affect evapotranspiratin
2) disease= increase funal like infectinos
what can high PHs in soil cause
root damage by toxic conc of protons or oh-
what can changes in PH cause
influence nutrient availability and toxin conc
give some examples of areas with extreme PH
geothermal springs
volcanic lakes
how did begon et al 2006 define resources
entities required by an organism that may be reduced by the activities of other organisms
what is the consequence of resources
competition
how is solar energy a resource
solar radiation is the only source of energy for photosynthetic organisms and shading by other organisms can deplete it
how is carbon dioxide a resource
used in photosynthesis and availability varies depending on position in the habitat
how is water a resource
hydration is needed for metabolic reactions and must be replenished
how is oxygen a resource
diffusion and soluability of oxygen is low in water so is limited in aquatic and waterlogged environments
what does the term polyphagous mean
organisms which have a wide variety of prey species
what defences have prey organisms developed
1) physical and chemical
2) behaviour and morphological
what is an ecological niche
a summary of an organisms tolerances and requirements- describes how rather than where an organisms lives
what is a fundemental niche
where an organism could live in the absence of competition and predators
what is a realised niche
where an organism actually lives when competitors reduce available resources
what are the dimensions of a niche
1) conditions and resources
2) predators
what are the roles of environmental tolerances
when a species is limited in distribution it is said to be restricted in distribution it is said to be restricted according to be environmental tolerances
