I'm going to make a globe which contains organism, mainly animals and plants.

What do you suggest me to put it inside?

There is a competition for me.

I am required to make them alive as long as possible. No extra things can be put inside after the globe is sealed.

I think it's quite like the matters in geography.

Plants, lots of them, to provide sustainable food and O2 levels, plants like water as do animals, so you`ll need that, as well as light, but not a "HOT" light, as the internal temp can get extreme (like in a greenhouse).

I`de also have a propper day/night cycle too, say 16 on (daylight) and 8 off (night time).

that`s about it for now

Pond water.

 

It's easy, i did it at school. Just fill up with samples of water from a few different sites and wait. Algae, plants, invertaberates all appear and after a short while develop a stable eco system. Just make sure there is sufficent bio mass (ie, a couple of handfuls of rotting leaves.)

 

It'll last pretty much indefinetely and each one is different so you can have fun comparing if you do more than one.

 

Have fun.

Ya the ecosphere is very interesting.