Research Nugget

Modern Pollen Rain Reveals Landscape Differences in Madagascar

Studying pollen is an effective way to learn about the past and present landscapes, including how they have changed over time. By examining the amount and type of pollen, we can understand how humans have impacted the environment and how it can be improved. However, in Africa, especially Madagascar, pollen studies are limited due to a lack of plant references and data sharing among scientists. By conducting more of these studies, better conservation guidelines for natural resources can be established.

Research funded by the NRF examined soil and lake sediment samples to study modern pollen distribution across Madagascar’s main vegetation types. The research goals were:

  • Characterisation of modern pollen from four major vegetation types;
  • Understanding pollen-vegetation relationships; and
  • Setting of baseline values for the interpretation of fossil pollen records in Madagascar and other tropical regions.

The researchers collected seven soil samples from Northwest Madagascar’s Tropical Dry Forest and analysed them for pollen content. They used data from various sources and sediment core datasets to identify the pollen and analyse vegetation composition among samples using multivariate analysis techniques.

The study found that pollen can be used to distinguish between four main types of vegetation in Madagascar. The researchers analysed 21 samples from the surface of the soil in four different regions, and identified 205 types of pollen (excluding aquatic, unknown, and broken specimens). Out of these types, 83 had a frequency of over 2%, and 39 types were found in more than 5% of the samples. This indicates that certain types of vegetation are dominant in specific areas.

Researchers were able to examine the pollen collected in the samples to determine the composition and structure of vegetation. They characterised the vegetation as open and mosaic, forested, or degraded by identifying dominant and characteristic taxa.