Once all the information is quantified, the identifications are plotted as curves on a pollen diagram. Fluctuations in the curve for each plant category may indicate signs of climatic changes or forest clearance and crop planting by humans. Most paleolimnologists look for sediments for preservation of pollen in acidic and poorly aerated peat bogs and lake beds. Here biological decay is impeded and grains go through rapid burial. Cave sediments are also a good place to find useful sediments because of their humidity and constant temperature.
Most pollen grains preserve well once they have settled at the bottom of a water system.
They can be identified as a species to provide measures of each species in proportion to its density and past population dynamics. Stratigraphy is important when studying paleolimnolgy. Stratigraphy of pollen and spores provide evidence of chronology for vegetational changes in the drainage basin related to changes in temperature, rainfall, soil development, and disturbances cause by the activities of humans. The most common algal microfossils preserved in lake sediments are the siliceous frustules of diatoms. For example the cysts or scales of chrysophytes or dinoflagellates.