The Brazilian Cerrado through herbarium lenses: vegetation structure and composition across savanna, forest, and...

The Cerrado is a biogeographic domain located in the heart of South America. Of continental proportions, it harbors remarkable plant diversity across numerous vegetation types. In recent years, the Cerrado has received increasing attention due to its central role in providing ecosystem services. This growing interest, however, has also led to confusion about its vegetation, with different sectors of society interpreting its plant communities in diverse ways. To clarify Cerrado's vegetation patterns, this study provides a decentralized synthesis based on over 600,000 herbarium records.

Herbarium records were retrieved from GBIF and those sampled within the Cerrado were selected. Specimens with labels containing information on plant form, height, and vegetation type were analyzed after filtering. Major patterns of vegetation structure were analyzed, including growth-form proportions as well as mean and overall plant height across 13 vegetation types belonging to savanna, forest, and grassland formations. Vegetation compositional dissimilarities among vegetation types and formations were also examined using clustering analyses. Species and family dominance were assessed using threshold-based approaches, focusing on the highest representation in records.

Herbarium records reveal a strong openness gradient in vegetation structure, with forests dominated by trees, grasslands by herbs, and savannas showing intermediate composition with higher shrub and subshrub abundance. Growth forms shift from woody to herbaceous dominance, while plant height declines markedly from forests to grasslands but not necessarily within formations. Clustering analyses reinforce this separation, with savannas and grasslands more similar to each other than to forests. Most common species and families according to records highlight the prominence of monocots and the occurrence of growth-form switchers.

These results provide a comprehensive and decentralized overview of the different formations and vegetation types within the Cerrado, offering insights for advancing our understanding of this threatened domain while revisiting theoretical perspectives on its enigmatic vegetation.