This paper aims to propose an economic instrument evaluating the multidimensional performance of the forest ecosystems. The production theoretic approach to index numbers is considered as theoretical foundation for the performance assessment. Specifically, disaggregated index number is introduced highlighting multidimensional performance measure of the forest ecosystems, by considering economic and environmental dimensions alike. As a result, this paper provides environmentally-adjusted index number permitting to evaluate the economic health of the forest ecosystems. Interestingly, the approach introduced in this paper highlights the Economic-Environmental (EE) performance nexus of the forest ecosystems. Moreover, an econometric model is proposed allowing to estimate the multidimensional performance index of the forest ecosystems. Specifically, a non parametric analytical framework is provided highlighting the practicability of the approach introduced in this paper.