EFFECTS OF SECOND ROTATION SEEDLINGS AND COPPICE ON UNDERSTOREY VEGETATION AND TIMBER PRODUCTION OF EUCALYPTUS PLANTATIONS

Abstract

Replanting with seedlings or regenerating with coppice in second rotation is a major forestry managementregime in short rotation forestry (SRF), but little is known about its effects on understorey vegetation conservation, timber production and economic benefits. To evaluate the effects of second rotation seedlings and coppice regime on the composition, structure and biomass of understorey vegetation, timber production and economic benefits of Eucalyptus plantations, a long-term (14 years) comparative study was conducted using three rotation regimes: (1) the first rotation planted with seedlings (FRs), (2) second rotation replanted with seedlings (SRs) and (3) another second rotation regenerated with coppice (SRc). Both successive rotation regimes significantly decreased the species richness, diversity and evenness of the total understorey vegetation. SRs did not affect the abundance of understorey species but significantly decreased the coverage and biomass of understorey vegetation. SRc significantly increased the abundance of the understorey plant species and maintained the coverage and biomass of the understorey vegetation equivalent to FRs. SRs showed the highest stand volume and net present value, however the highest internal rate of return occurred in SRc due to the reduced establishment and management costs. This suggested regenerating with coppice should be a more suitable successive rotation regime for increasing economic benefits as well as biodiversity conservation in south China.