A, the amount of I in the producer is equal to the amount assimilated by primary consumers plus the amount in their feces. A is wrong;

The energy in B and H is mainly lost in the form of heat energy, while the energy in K cannot be absorbed and utilized by producers. The organic matter (K) flowing to the decomposer can be utilized by producers only after it is decomposed into CO2 and inorganic salts. B is wrong;

C, the amount of CO2 entering the ecosystem, that is, the amount of CO2 fixed by producers, is greater than the total amount of CO2 generated by decomposition and consumption of H at various trophic levels, and C is correct;

D, the information transmission of ecosystem can regulate the energy flow and material circulation, and D is wrong.

Therefore, ABD ..