Abstract: In order to study the organic carbon nitrogen phosphorus nutrients content, loss of these nutrients, C/N/P stoichiometric ratio of Pinus massoniana litter and soil in different sized P.massoniana forest gaps. In the present study, with existing 42 years of P.massoniana plantation, by cutting, formed four different sized P.massoniana forest gaps about 100, 400, 900, 1 600 m² and without cutting as usual. Bying leaf litter decomposition method. The results showed that:(1) With different sized forest gaps, the organic carbon nitrogen phosphorus nutrients content, loss of these nutrients and C/N/P stoichiometric ratio of P.massoniana litter and soil had significant differences, in addition to the phosphorus nutrients content of soil and phosphorus nutrient loss. With the increasing of gap size G1~G4, the content organic carbon nitrogen phosphorus nutrients content of P.massoniana litter all showed a decreasing trend and had smaller values in G3. Most index of the content organic carbon nitrogen phosphorus nutrients content of soil, the content organic carbon nitrogen phosphorus nutrient loss showed a parabolic trend and had the maximum value in G2 or G3; (2) With different sized forest gaps, the C/N/P stoichiometric ratio of P.massoniana litter and soil had significant differences. With the increasing of gap size G1~G4, the C/N/P stoichiometric ratio of soil showed a parabolic trend, C/N had the maximum value in G3, both C/P and N/P had the maximum value in G2. The Soil C/N, C/P and N/P coefficient of variation were 13.31%, 16.51% and 17.21% respectively. Both C/N and C/P of P.massoniana litter had the minimum value in G3; (3) There were a strong correlation relationship between the organic carbon nitrogen nutrients content of P.massoniana litter and the organic carbon nutrients content, C/N/P stoichiometric ratio of soil, environmental factors, while a weaker correlation relationship between phosphorus nutrients content of P.massoniana litter and them. There were a strong correlation relationship between C/N of P.massoniana litter and the phosphorus nutrients content, C/N/P stoichiometric ratio of soil, environmental factors. There were a strong correlation relationship between C/P, N/P of P.massoniana litter and the C/P of soil, environmental factors. There were a strong correlation relationship between organic carbon nitrogen nutrient loss and the organic carbon C/N, C/P of soil, environmental factors. There were a weaker correlation relationship between phosphorus nutrient loss and the organic carbon nitrogen phosphorus nutrients content, C:N:P stoichiometric ratio of soil, environmental factors. There were a strong correlation relationship between the organic carbon nitrogen phosphorus nutrients content, C/N/P stoichiometric ratio of soil and environmental factors.

Key words: Pinus massoniana plantation, forest gap, nutrient loss, P.massoniana litter, soil, nutrient content