PROJECTIVE LEAF COVER PREDICTS PLANT SPECIES RICHNESS IN THE SACRED FIR FORESTS OF MONTE TLÁLOC, STATE OF MEXICO

The establishment of relationships between the water balance coupled to the atmosphere and species richness, for a given ecosystem, allows characterizing the state of vegetation under stable conditions. The proposal by Specht and colleagues of the water relationship between actual evapotranspiration/potential evapotranspiration (Ea/Eo), mediated by the evaporative coefficient k, allows to establish empirical relationships, without implying a cause-effect relationship, between the projective leaf cover (CPF) and the richness of plant species in relation to k. These relationships were reviewed with information from sampling sites established in sacred fir [Abies religiosa (Kunth) Schltdl. & Cham.] forests of the warm temperate climatic region of Mount Tlaloc, State of Mexico. Species richness and CPF of the upper stratum of the forests were measured, and the aboveground biomass was estimated. The patterns of the relationship between the CPF of the upper stratum and the total number of species showed variations within the limits of Specht’s equilibrium relationship, even though the levels of disturbing agents in the sites showed a greater dispersion of the data. Establishing a relationship between projective leaf cover and species richness facilitates estimates in plant diversity conservation projects.