Ecosystem service multifunctionality of Chinese fir plantations differing in stand age and implications for sustainable management

Establishing forest plantations is an important solution to the growing conflict between an increasing human population and mounting pressure to protect the natural forests, as plantations also harbor great potential for providing multiple ecosystem services (ESs). However, because of the trade-offs between multiple ESs and the conflicts between different stakeholders, the sustainable management of plantations has been exceedingly challenging. Especially in recent years, with China's emphasis on ecological civilization construction and sustainable development, forestry departments have begun to focus on long-term ecological benefits, which conflict with farmers' attention to short-term economic gains. In this study, we quantified 15 field-based ES indicators from the data measured in Chinese fir (Cunninghamia lanceolata) plantations aged 4 to 32 years. Corresponding to the concerns of two different stakeholders (forestry departments and farmers), we calculated ES-multifunctionality with different thresholds under four management scenarios: equal weight, production only, production multifunctionality, and supporting multifunctionality. Our results suggested pronounced stand age effects on both individual ESs and ES-multifunctionality of plantations. For individual ESs, stand age had a greater impact on provisioning services than on supporting services. High degree of trade-offs existed between plantation provisioning ESs and soil nutrient supporting ESs, and between water relevant ESs and the other ESs. With respect to ES-multifunctionality, the values under different scenarios were all augmented with stand age, but to differing degrees. The values for supporting multifunctionality were higher than those of production multifunctionality and production only before 21 years of stand development, but completely reversed once the fir plantations reached an age of 25 years. Finally, several stage-based plantation management recommendations are proposed to minimize conflicts between different stakeholders. Our results combined measures of temporal stability and multifunctionality, thereby providing valuable and timely insight into the multifunctional stability of plantations represented by Chinese fir.