ObjectiveStand density management diagram (SDMD) is an effective tool for designing, displaying and evaluating different management measures, and hence provides decision support for even-aged forest management. The objective of this study was first to construct a SDMD for Pinus massoniana plantation for the Tropical Research Center (TRC). Second, based on the SDMD, the stand density of TRC was evaluated and an early warning diagram (EWD) of stand density was further produced with relevant management suggestions.

MethodThe data used in this present study consists of 238 permanent sample plots, which were established in 2011 and re-measured in 2013 and 2015. The Reineke self-thinning equation was used to develop the SDMD. Based on the SDMD, the EWD for TRC was produced using the forest management planning data.

ResultBased on the optimal density upper and lower limits, dominant height model, volume model and site index model, we constructed the SDMD for Pinus massoniana plantation in TRC. According to the SDMD and the stand density, the EWD was constructed and the management suggestions were provided.

ConclusionIn this study, we divided the Pinus massoniana plantation in TRC into three different stands, i.e., high-density stands, low-density stands and the optimal density stands. For the three different stands, different management strategies were proposed. For high-density stand, we can conduct the thinning operations to decrease the density and achieve optimal density stands conversion. For low-density stands, the management measures of replanting precious tree can be conducted, which could contribute to the development of reasonable density. Compared with the above two stands, the optimal density stands could not be conducted any management strategies, which can support the formulation of the Pinus massoniana plantation management strategies.