Deriving Response Matrices from Central American Modern Pollen Rain

Modern pollen samples collected from 80 locations and representing a wide array of mature habitats in Panama and Costa Rica provide analogs to assist in the interpretation of fossil pollen records. Pollen spectra accurately reflect changes in actual forest types. Upslope transport of pollen of anemophilous species is evident in the sparsely vegetated montane samples. However, the corresponding downslope transport of these prolific pollen producers is masked by local pollen production. Mean pollen representation across gradients of mean annual temperature (MAT; 4°C increments) and mean annual precipitation (MAP; 500 mm increments) for 17 pollen types are presented as response matrices. Although preliminary in nature, these response matrices present a clearer image of pollen representation than can be obtained by considering gradients of MAT or MAP alone.