Some organisms use chemosynthesis to survive. where do they get their energy for this process

The substances such as hydrogen sulfide and ammonia are oxidized to obtain energy in the presence or absence of oxygen.

Explanation: Many organisms that live in the darker regions of the ocean use this technique to derive energy as sunlight cannot reach there to perform the process of photosynthesis.

The energy obtained by this process is used provide energy to the organism which is used for sustaining life in the deep down ocean.

explanation:

for  example, forests have higher evapotranspiration than other ecosystems,  such  as grasslands, because of their deeper roots and greater leaf area. thus forests have a net moistening effect on the atmosphere and become a moisture source for downwind ecosystems.