Study on the Characteristics of Different Organic Residue Decomposition of Triploid Populus tomentosa

Litter such as leaves and branches are the main source of nutrients and energy in forest ecosystems,and their decomposition process and rate influence nutrient cycling and energy flow. To verify the status of nutrients of triploid Populus tomentosa pulp plantations,and seek feasible ways to supply more nutrients to maintain and improve long-term soil productivity,a litterbag method was employed to study the rate and law of the decomposition process of fine branches (Ф < 0.5 cm),leaves,fine roots (Ф < 2 mm) and bark. After one year,the decomposition process patterns of leaves,bark and fine branches on the soil surface were similar,but the decomposition of fine roots differed as they were embedded in the soil. At the end of the experiment,the decomposition rates of fine roots,leaves,bark and fine branches were 42.5%,30.5%,26.0% and 20.9%,respectively. These results showed that different residues had different characteristics and needed to employ proper measures to promote decomposition and improve site productivity.