Marco Chiminazzo: ‘your best buds are worth protecting’, plant strategies to cope with fire in Cerrado (Brazil)

In our latest post PhD candidate at Universidade Estadual Paulista, Marco Chiminazzo, presents his work ‘Your best buds are worth protecting: woody species exhibit different types of bud protection’, discuss about the importance of plant traits to cope with fire and shares how he got inspiration from Punk music to pursue his research career.

About the paper

Marco Chiminazzo
Marco Chiminazzo

In this paper we analysed how bud traits are distributed across species from forests and savannas, among trees and shrubs, and the different post-fire resprouting strategies. During fire, woody species have their aerial parts consumed or scorched by the flames and the hot airflow. While savannas are dominated by flammable C4 grasses, forests lack this flammable layer and houses fire-sensitive species. Therefore, to persist in savannas and under recurrent fires, plants must be able to regenerate by resprouting new shoots after fire. The potential of resprouting new branches is closely related to how well buds (structures that develop into new branches) are protected from the flames. Therefore, we aimed to explore what types of bud protection Cerrado woody species have and if it differed across savannas and forests, trees and shrubs, and different resprouting strategies (new branches coming from the base of the trunk, from belowground, from the trunk, or from branches and twigs). 

Moquiniastrum polymorphum resprouting branches after fire
Moquiniastrum polymorphum resprouting branches after fire

We observed that species protect their aerial buds using bark, but also by developing a thick layer of trichomes (hairs). We found that shrubs capable of resprouting aboveground better protect their buds than trees, and that species with higher bud protection by bark occur in savannas while those with low bud protection occur in forests. Trichomes were more related to savannas where fire is an important driver. Two months after a fire event, we saw some species that had their buds protected by trichomes resprouting aboveground, from tall branches and twigs. Based on these results we suggested that trichomes may help to ameliorate the impacts of the hot, dry airflow that emerges with the fire plume during fire events. These observations allowed us to draw a conceptual model based on bud-related traits and the position of the resprout after fire.

Trichomes, accessory buds and bark covering the buds were traits more related to savanna trees exposed to fire. Therefore, it is possible to highlight three key messages of this paper: i) Cerrado woody species are incredibly adapted to fire; ii) one species can present more than one type of bud protection (like bark and trichomes) iii) the position of the new shoot depends not only on how well the buds are protected, but also on fire severity. 

About the research

Research integrating plant traits and fire is very important. Fire is a major factor of several ecosystems worldwide, and its effects over different vegetation has been gaining attention over the years. Intriguingly, there are species that are okay in living in environments with fire, which seems to be the case of the Cerrado woody species. Understanding how species resprout after fire and which traits allow them to do so give us an opportunity to better understand the functioning of savannas and how fire influences vegetation responses.

Cartoon about buds, trichomes (hairs) and fire in savannas. © Marco Chiminazzo
Cartoon about buds, trichomes (hairs) and fire in savannas. © Marco Chiminazzo

This type of research can be exhaustive (but fun), and that was the case here. We sampled 4,512 woody plants across four different Cerrado vegetation types (two forest and two savanna ecosystems), and the post-fire responses of more than 1,300 savanna woody plants. Then, for each one of the 123 sampled species, we collected samples from three different individuals to search for buds in their branches. Lab work consumed a ton of time, but it was totally worth it to see the huge diversity of buds present in the Cerrado woody species – as well as their post-fire responses. Regarding the field sampling, things went well until November 9th, 2019. On November 10 I was going to the field to sample more individuals, but on the night before that a huge fire storm burnt the area that I was working in. As every challenge creates a new opportunity (it is cliché but it is true), we decided to expand the research and perform surveys about the woody species post-fire resprouting. This allowed us to test if the bud traits could be associated with a better resprouting response, which turned out to be a very important part of the paper.

I think that the next step of this research would be to test, using anatomical methods, the variation in hairs of buds from fire-prone and fire-sensitive environments (like savannas and forests, for instance). It would be also important to check if species from environments other than the Cerrado also present trichomes protecting their buds, as fire regime differs across different savannas worldwide. In conclusion, research considering an integrative approach of vegetation ecological aspects and  plants’ anatomical traits can be very valuable and bring a new perspective on our understanding about plants and fire.

About The Author

Marco sampling savanna environmental conditions in the Cerrado
Marco sampling savanna environmental conditions in the Cerrado

As far as I can remember, I was always curious about things, and I guess I just focused my questions on the biology/ecology field with the guidance of my advisors. I am very into punk music, and the influences of Dr Milo Aukerman (Descendents) and Dr Gregg Gaffin (Bad Religion) were definitely there when I decided to start in academic life (and also when I started to play bass!). During my undergraduate years, I was able to be part of different research groups, from geoprocessing to animal research, performing small and local studies. These were fundamental for my development as a researcher and to learn two important aspects about my interests in science: i) plant ecology is awesome and ii) taxidermizing dead animals is definitely not for me. 

Currently I am a PhD student at the Universidade Estadual Paulista (UNESP), in Brazil. My research focuses on coexisting savanna-forest biomes, aiming to understand the influences of fire and light availability on species traits and community assembly from both intra- and interspecific perspectives. I am very interested in combining different methods (morphological, anatomical, and physiological) to better disclose the costs and strategies from woody plants inhabiting savanna-forest transitions. I consider myself very lucky to be part of such a strong research group that allows me to learn different techniques and apply them to my research interest (check our site for several research in the Cerrado: https://levegunesp.wixsite.com/leveg). 

This paper published in Functional Ecology is the scientific contribution that I am most proud of.  It is my second paper on an international peer-reviewed journal and concerns the first chapter of my Master thesis, which was advised by all co-authors. The development of this research, combined with the several writing versions of the manuscript, took almost two and a half years. A lot of things happened during this time, including the Covid-19 pandemic that slowed down the research, so I am very happy to see that all the hard work was worth to contribute with our understanding about woody species persistence.

I am looking forward to continuing studying and learning as much as I can about plant science – especially anatomy, morphology, and their relationship with environmental conditions. I am also very interested in learning and exploring environments other than the Cerrado. In the future I hope to become a Professor, but for now I am incredibly happy to be a PhD student! 

Read the paper in full here.

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