(1) Acer truncatum, Acer truncatum, Betula platyphylla and other tree species are all producers of this ecosystem, all of which belong to the first trophic level, and there is a competitive relationship among them. Usually, marker recapture method is used to investigate animal population density. In general, the number of seconds is small, so the data is greater than the real value.

(2) In this temperate forest, there are about 6.28× 105J/(cm2? A) Organic debris can't be decomposed by various decomposers, indicating that the decomposition ability of decomposers is limited, and the main environmental factor affecting the decomposition efficiency of decomposers is temperature. When the temperature in the cold zone is low, the decomposition rate of the decomposer decreases and the energy ratio increases.

(3) It is known that the fixed solar energy of producers is 2.3× 107 J/(cm2? A) The energy flowing to the primary users is 3.27×105-1.31×105 =1.96×105j/(cm2? A), so the transfer efficiency is about (1.96×105) ÷ (2.3×107) = 0.85%. According to the energy value analysis in the figure, the decomposer's breath is the main channel of energy flow;

(4) Because the ecosystem has a certain self-regulation ability, the species and quantity of creatures in the forest will not change obviously because of the migration, birth or death of a few animals.

So the answer is: (1) competition? The tag recapture method is large.

(2) Big

(3)0.85? Decomposer

(4) Self-regulation