Phytoliths are particles of silica produced by different groups of plants with functions that can vary from protection against herbivory to structural purposes. It turns out that when the plant dies, these small pieces of silica settle in the soil or lakes and can be preserved in these environments for millions of years. Therefore, identifying such particles is extremely important to be able to reconstruct and interpret the dynamics of past environments.
Reference collections of plants and surface soils are a critical part of studies that use phytoliths for archaeological and palaeoecologically reconstruction. In the archaeologically rich region of the Upper Madeira River in Rondônia, Brazil, for example, phytolith analysis is helping researchers understand the interaction between humans and the environment during the Holocene (the last 11.500 years).
The study, carried out by Jennifer Watling, a postdoctoral researcher based on MAE-USP and a member of the HERCA project and collaborators, brings together data on phytolith production patterns among 90 native species, representing 36 plant families, as well as 56 surface soil samples taken from underneath 11 monitored forest plots.
In this study, published at the Quaternary International journal, the authors compared the surface soil phytolith records with the above-ground floristic inventories. One of the findings of this study shows that the phytoliths of several species that produce diagnostic (very specific types of phytoliths) or potentially-diagnostic morphotypes were under-represented in the surface soils, including several understory herbs.
The study highlights the importance of reference collection material, not only to improve our knowledge but to increase the accuracy of future studies when reconstructing the relationship between past civilizations and their environment.
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