Community and biotic/abiotic factors?

Question

So in my bio book it says "a community consists of all the organisms of all the species that inhabit a particular area. it is an assemblage of populations of many diff. species.

it goes on to talk about how ecologists study interactions. etc. etc.

the it says:

"...abiotic factors such as disturbance affect community strucure and organization"

I thought that community only includes biotic factors such as predation, competition and disease, not abiotic factors. Ecosystem then includes abiotic AND biotic factors. Can you correct my understanding if im wrong?

Thank You!

Answer 1

Yes, I think you have it right.

Community ecology is the study of the biotic organisms.  However, the community can be affected by abiotic factors.  You can study how abiotic factors effect the biotic community (e.g. nutrients effects on plant diversity), but this is starting to get into ecosystem ecology.  These two disciplines often overlap -- it's hard to say exactly when you cross from community ecology to ecosystem ecology.  One thing that separates them is that ecosystem ecology usually focuses on flows and fluxes of energy and matter through an ecosystem (e.g. nutrient cycles).  

So you are right that community ecology is biotic interactions and ecosystem ecology is abiotic + biotic interactions, but there is not always a clear distinction.

Another thing is that community ecology will focus on the species or functional groups (tree growth in response to herbivory).  Ecosystem ecology will focus on the ecosystem as a whole system -- it will ignore the species and focus on whole ecosystem processes.

Hope that helps to clear things up a bit.