ecosystems

ecosystems

interaction of many organisms functioning together through physical and chemical environments, composed of biotic and abiotic factors that cycle

the ecotone

the intermediate zone between two systems a transitional zone from one type of ecosystem to another

structure of ecosystems

non-living are the physical-chemical aspects, i.e. local climate, water, soil, and temperature; living is the ecological community, a set of species interacting within ecosystems

process of ecosystems

cycling of chemical elements and flow of energy through systems

change in ecosystems

succession; ecosystems aren’t static and are always changing

five important ecosystem cycles

water, carbon, nitrogen, phosphorus, and sulphur

non-living/abiotic factors

abiotic factors affect the ability of organisms to survive, each individual in a population can have a slightly different response to the abiotic environment, reflecting the sum of individual variation

generalist species

species that have wider ranges of tolerance and can live in a variety of habitats, i.e. raccoons, rats

specialist species

species that have narrow ranges of tolerance and have a restricted distribution, i.e. pandas

species niches

the summation of all physical and abiotic factors that a species needs to live

food chains

energy, chemical elements and components transferred from one creature to another

food webs

more complex cases, non-linear, have the same underlying trophic patterns: at the top, secondary consumers/carnivores (heterotrophs), then primary consumers/grazers/herbivores (heterotrophs), producers (plants/autotrophs), and tertiary consumers/decomposers at the bottom

autotrophs (self-feeders)

feed themselves through photosynthesis

photosynthesis

the process of turning inorganic carbon into organic carbon and capturing energy

heterotrophs (other feeding)

feed themselves by consuming organic carbon already fixed by autotrophs and extracting its energy via respiration, which is then available for growth reproduction

2nd law of thermodynamics

tells us there will be an inevitable loss of useful energy with the progressive movement to higher and higher trophic levels, and eventually there won’t be enough energy to support an additional trophic level

all systems are interconnected

terrestrial biomes are connected by rivers, sediments and nutrients from land wash into aquatic ecosystems, all share a common hydrologic cycle and a common atmosphere

the biosphere

term referring to how all species on Earth and their environments can be considered one vast ecosystem

keystone species

species that drive the functioning of whole ecosystems and have a critical role in maintaining the overall relationships within an ecosystem; a strongly interacting species that has a top-down effect on the diversity and competition that is large compared to its biomass

geographic variation

the variation in kinds and numbers of species found on the planet

biomes

characteristic assemblage of plants and animals that have adapted and evolved to specific climatic conditions can be classified by a system corresponding to latitude and humidity

terrestrial biomes

tundra, desert, boreal forest, tropical rainforest, tropical dry forest, savanna, mountains with complex zonation, chaparral, temperate grassland, temperate deciduous forest and temperate grassland

precipitation and biomes

how wet an area is can shape the environment

high latitude biome

less variation; temperature is more important than precipitation in shaping the biome

lower latitude biome

precipitation and the amount of moisture are more important in shaping the biome, similar temperatures and the amount of precipitation determine whether it’ll be a tropical rainforest or a dry tropical desert

gross primary productivity (GPP)

the amount of organic matter that is produced through photosynthesis, though not necessarily the amount that can be moved up to the next trophic level

net primary productivity (NPP)

the amount of energy available for plant growth after subtracting the fraction that plants use for respiration, what is available for the next trophic level

top-down regulation of ecosystem functions

abundance of predators determines the trophic levels that exist in a particular system

bottom-up regulation of ecosyste functions

resource availability at the bottom (plant mass) determines or controls how that ecosystem functions

ecological niche

what an organism does for a living, how many herbivores, predators, etc in an ecosystem; measured as a set of all environmental conditions under which species can persist and carry out its life function

competition exclusion principle

two species that have exactly the same requirements cannot coexist in exactly the same habitat, niche overlap leads to competition over the same resource

habitat complexity

when a habitat has a variety of different niches, it allows for more different kinds of species to exist

fundamental niche

having a wide tolerance range; doesn’t guarantee a species will occupy the whole of the niche

realized niche

biological interactions with other species may restrict organisms to a realized niche that is a smaller fundamental niche

symbiosis/mutualism

interactions between species that benefit both, the most popular relationship found in ecosystems, the most efficient

competition

interactions between species where the outcome is negative for both, not sustained over a long-term (i.e. wood warblers)

parasitism (predator)

interactions between species that benefit one but are detrimental to another, i.e. wasp larva on a caterpillar

co-existing species

species of organisms coexisting today could be the result of competitive interactions that took place thousands or millions of years ago