Abstract:Species biodiversity and water conservation ability of 4 types of forests (Choerospondias axillaris forest,Pinus massoniana untended forest,Pinus massoniana tended forest and P.massoniana-C.axillaris mixed forest) were compared by the methods of community investigation,soil and litter analysis in Qingyanghu State-owned Forest Farm.The results showed that:(1) 135 vascular plants were found in all 4 forests,which belongs to 97 genera and 58 families.Choerospondias axillaris forest had 88 species,ranked the first order in species richness of 4 forests;Pinus massoniana-Choerospondias axillaris mixed forest had 76 species,ranked the second order;P.massoniana tended forest had 64 species,ranked the third order;P.massoniana untended forest had 55 species,ranked the fourth order.(2)Forest type had an important effect on species diversity,both C.axillaris forest and the mixed forest had higher species diversity in herb plants than Pinus massoniana forests,but lower species diversity in shrub plants.(3)DCA results indicated that C.axillaris forest and the mixed forest had higher similarity than P.massoniana forest.(4)Forest type had an important effect on water conservation capacity.Compared to P.massoniana forest,the litter amount of C.axillaris forest and the mixed forest was decreased 10.1% and 15.2%,respectively;litter water retention increased 34.1% and 44.7%;the soil bulk density decreased 14.7% and 7.4% at soil depth of 0-10 cm,decreased 14.1% and 4.0% at 10-20 cm,and decreased 8.7% and 4.9% at 20-30 cm;the total water-holding capacity increased 15.8% and 4.5%,respectively.The results also showed that the water conservation capacity of P.massoniana forest was increased by ecological tending.