ABSTRACT
Most of the time, functionality indicators may be used as an indicator system, rather than individually, as a collection of indicators viewed as a whole to provide a better assessment of the integrity and health of the ecosystem. This chapter focuses our interest on the functioning of plants as an important part of the ecosystem. Forest functionality indicators are an especially complex area, as the estimation of something as simple as biomass demands a large number of measurements, estimations, and models. The ecological role of living organisms such as plants can be assessed with quantitative measurements or with statistics over time. These types of indicators are of the type known as sustainable development indicators, which track sustainability with respect to the environment. Forest functionality indicators are an especially complex area, as the estimation of something as simple as biomass demands a large number of measurements, estimations, and models and is approximate and inaccurate.
