We're dealing with a complex system, where there's not a linear effect from
a single cause to a single outcome, and then onto another effect.
There are multiple stressors, multiple drivers of environmental change, multiple
causes of species extinction or decline of abundance and genetic diversity.
We need to understand the complexity of this system because no single approach
is going to be sufficient to [COUGH] reversing the trends that are underway.
Heading off this sixth great extinction that is a threat,
to not only millions of other species, but to one that we also have a
especially strong vested interest in, and that's Homo sapiens, that's us.
And so we need to get into the very complex nature of this threat.
You're looking at an example of biodiversity, the incredible diversity
of species and interactions in this marine environment that you're viewing right now.
And of course, what you see are multiple species of animals and plant life.
Many species are microscopic, and you don't see them.
You see the interactions of the fish,
corals, and we know the microscopic plankton
for example in the oceans, with the non-living part of
the system in front of you, the fluxes of energy, of sunlight
of nutrients that are arriving in this
ecosystem from a variety of sources.
What is an ecosystem?
It is exactly that collection, of plants and animals and
microbial life, interacting with the abiotic or
nonliving part of the local system, with the energy and nutrient fluxes.
The key is that this is a set
of living organisms together with the non-living environment.
Interacting in a system and of course, what ecologists do
in studying ecosystems, is study the fluxes and dynamics of the system.
How does nutrient flow take place within a
food web and within the processes of metabolism.
Of, oxidation, respiration, [COUGH] and, photosynthesis, and other basic
processes of, the metabolism of the living organisms, within the system.
How does the diversity of the, species and the diversity of the individual
organisms within a species, affect the behavior of that whole ecosystem?
So when we have an ecosystem, we're also interested in another core concept.
And that is the biological diversity or biodiversity of that ecosystem.
And of the biodiversity across ecosystems, as
ecosystems, marine, and terrestrial, interact with each other, to produce
outcomes, at an even higher level, of aggregation and organization.
