The radius of the belt increases and decreases depending on the
flux of charged particles that bombard the magnetic field of the earth around the
region , equator. This increase and decrease is dependent on the solar
activity. Solar storm release charged particles that interact with the magnetic
filed.
Biomass decays and produces gases such as nitrogen and very small amount of helium. in many places it is used to produce energy by comustion.it's mass becomes less and a layer of humus type organic substance is left on the soil....if i'm not incorrect :)
A community with lots of plants and animals, that have a equal balance between them that is success of a community which can only be destroyed by a fire or human causes.
A. Average weather conditions over extended periods of time