
Trees in the Cerrado savanna area produce three times as much bark as
In tropical areas of the planet, savannas and forests often coexist in the same areas and are exposed to the same climate. An example is the Cerrado, a Brazilian biome that includes several types of vegetation, from broadleaf and sclerophyllous to dense forest or scrub (close sensu stricto) to semi-evergreen in closed canopy forest (savanna), as well as meadows with scattered undergrowth (dirty field) and even a spring-deciduous forest.
In tropical areas of the planet, savannas and forests often coexist in the same areas and are exposed to the same climate. An example is the Cerrado, a Brazilian biome that includes several types of vegetation, from broadleaf and sclerophyllous to dense forest or scrub (close sensu stricto) to semi-evergreen in closed canopy forest (savanna), as well as meadows with scattered undergrowth (dirty field) and even a spring-deciduous forest.
area of savanna thrives in the absence of fire on both poor and moderately fertile (dystrophic to mesotrophic) soils.
This coexistence intrigues botanists and ecologists because savannas and forests are home to different species and have different dynamics and functions. Savannas are dense, highly flammable grasslands that burn quite frequently, with direct impacts on other types of vegetation.
Forests, on the other hand, have broad, mostly continuous canopies that provide shade for undergrowth, shrubs and small trees, and prevent the growth of flammable grasses.
Savanna species evolved over millions of years in the presence of fire and have thick bark to protect them. After burning, they form new branches and leaves from asexual shoots called gemmae.
A study conducted in Santa Bárbara Ecological Station, an environmental protection unit in the state of São Paulo, investigated how much bark the savanna and forest species in the Cerrado produce, whether savanna species that produce more bark also protect their gemmae more effectively, and whether generalist species (occurring in savanna and forest). ) produce different amounts of bark depending on the environment in which they are grown. An article about this research is published in a journal History of Botany.
The main researcher for this research is Alessandra Fidelisa professor in the Department of Biodiversity at the Rio Claro Institute of Biosciences (IBRC-UNESP) State University of São Paulo.
The first author of the article is Marco Antonio ChiminazzoPhD candidate at IBRC-UNESP.
Another co-author is Alin BomboA postdoctoral fellow at IBRC-UNESP, and Tristan Charles-Dominique, a researcher at the Sorbonne in Paris and the University of Montpellier, both in France.
“We observed that savanna species produced about three times more bark than forest species, while species of intermediate generalist, produced more bark in savanna than forest areas. This ability to adapt bark production to the environment is known as phenotypic plasticity and may be a deliberate strategy. We also found that species that produce more shells better protect their gemmae and internal tissues,” said Chiminazzo FAPESP Agency.
“Our study shows that fire is an important factor for savanna-type vegetation on the Cerrado, promoting woody species that can cope with this disturbance and cannot thrive in shady forest areas.”
The study provides evidence strongly in favor of those advocating the use of carefully controlled fire to manage savanna areas in the Cerrado. A properly managed fire requires zoning and a schedule. Zoning establishes a mosaic framework for burning designated areas in rotation according to a schedule.
“The plant species on the Cerrado are fire-adapted, producing thick bark and protecting their gemmae tenaciously. These features, which are the result of a long evolutionary process, allow them to survive fire and regenerate after being burnt,” said Fidelis, who was the supervisor of the Chiminazzo thesis.
Remainder
Located in the municipality of Águas de Santa Bárbara, the ecological station where the research was carried out is an important original Cerrado remnant in the state of São Paulo and contains all the different types of savannas and forests found in the biome. “We sampled shrub and tree species from four different types of vegetation with varying burning frequency and light availability. We investigated the amount of bark they produce as they develop and how they protect their gemmae from the effects of fire. We then separated the species according to the environments they preferred to inhabit, forming three groups: savanna specialists, forest specialists, and generalists (able to grow in both),” said Chiminazzo.
Future research should be carried out to understand how and why certain species are able to adapt bark production, while others cannot, he added. “In the context of climate change and changing fire regimes, accumulating deeper knowledge about these species offers a great opportunity to understand and predict which organisms will be more or less endangered, according to their ability to adapt to various environmental conditions,” he said.
This study was supported by FAPESP through a Young Investigator Grants given to Fidelis. Additionally, Chiminazzo received a masters scholarship fund doctoral scholarship.
About the São Paulo Research Foundation (FAPESP)
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Article title
Bark production of generalist and specialist species in savannas and forests on the Cerrado
Article Publication Date
18-Jan-2023