Ecosystem
An Ecosystem is the dynamic complex of plant,
animal and micro-organism communities and their non-living
environment interacting as a functional unit.
Ecosystem function is dependent upon the
dynamic relationships within species, among species and between
species and their abiotic environment, as well as the physical and
chemical interactions within the environment. Ecosystem
function is determined by the interactions between biodiversity
dynamics, ecosystem processes, and abiotic factors.
Ecosystem process is an intrinsic
characteristic whereby an ecosystem maintains its integrity.
Processes include: decomposition; production; nutrient cycling; and
fluxes of nutrients and energy.
Ecosystem properties describe the size,
biodiversity, stability, organisation, and the internal exchanges
of materials, energy, and information among different assemblages,
as well as other properties that characterise an ecosystem
(including ecosystem functions and processes).
Ecosystem ‘stability’ or ‘robustness’ express
the dynamic properties of an ecosystem. An ecosystem is considered
stable or robust if it retains the ability to return to its
original state after a perturbation, exhibits low temporal
variability, or does not change dramatically in the face of a
perturbation.
Ecosystem resilience refers to an ecosystems
capacity to recover from severe disturbance and return to a
pre-disturbed state with no alteration to structure or
outputs. Resilient ecosystems are able to maintain taxonomic
composition, structure, ecological functions, and process
rates. Resilience is a function of biodiversity at all
scales: genes, species, landscapes, and spatial diversity within
and amongst ecosystems. Reduced resilience can lead to
uncertainty about future ecosystem condition.
Ecosystem resistance is the capacity of an
ecosystem to withstand the impacts of drivers without displacement
from its present state.
Ecosystem limits refer to different factors
present in the environment that control biotic and abiotic
processes within an ecosystem. The ecosystem
threshold describes the point or level at which new
properties begin to emerge in an ecological system which
invalidates predictions based on relationships that apply at lower
levels.
Ecosystem Condition describes the capacity of
an ecosystem to yield services, relative to its potential
capacity.
Condition of ecosystem service refers to the
capacity of an ecosystem service to yield benefits to people,
relative to its potential capacity.
Ecological redundancy, functional redundancy
or functional compensation is a characteristic of
ecosystems where more than one species can carry out a particular
process. Redundancy may be total or partial; that is, a
species may replace other species entirely or it may compensate
some of the processes in which the other species are
involved.