Background Soil erosion under Pinus massoniana forest is a current problem to be solved, it is an effective method to plant different broad-leaved trees in P. massoniana forest. However, different broad-leaved trees may cause diffident control results. Therefore, there is great significance to clarify the influence of control of broad-leaved species on the hydrological characteristics of litter layer.

Methods We chose 5 broad-leaved control forests and P. massoniana forest in Guizhou Longli forest zone. Combining with the outdoor investigation and indoor experiment measured the litter layer hydrology characteristic indexes, compared before and after the control of litter layer hydrology's feature differences through the entropy weight method to calculate index weight of different broad-leaved species control after 15 years of study of P. massoniana forst.

Results 1) Before and after the regulation of litter layer standing crop is shown as: P. massoniana+Manglietia chingii (8.62 t/hm²) > P. massoniana+Bretschneidera sinensis (8.03 t/hm²) > P. massoniana (7.73 t/hm²) > P. massoniana+Michelia maudiae (7.17 t/hm²) > P. massoniana+Cercidiphyllum japonicum (6.94 t/hm²) > P. massoniana+Camellia oleifera (6.34 t/hm²). 2) The leaf in litter layer took up the highest proportion at least 61%, stock and thicknes of the undercomposed layer are significantly greater than semi-decomposition layer. 3) Among the indexes for evaluating the hydrological characteristics of litters after regulation by different tree species, the weight of each index was ranked as follows: the density of litters' organ (0.174 0) > stock (0.157 2) > effective retention rate(0.157 0) > maximum water holding rate (0.144 1) > maximum water absorption rate (0.141 9) > thickness (0.133 4) > leaf area (0.092 6). 4) Between controled forest and P. massoniana, the comprehensive hydrological characteristics score of litters is ranked as: P. massoniana+M. chingii > P. massoniana+B. sinensis > P. massoniana > P. massoniana+M. maudiae > P. massoniana+C. japonicum > P. massoniana+C. oleifera.

Conclusions After being controlled by broad-leaved trees, the significant effect of litter layer hydrologic are M. chingii and B. sinensis and the worst is C. oleifera. In order to ensure the hydrological and ecological functions of the forest in the study area, it should be considered the differences between controlled broad-leaved tree species.