In our latest post, Mariana Campagnoli gives us a bite of the fascinating fruit to seed dispersal system of the Cerrado ecosystem in Brazil. Through their latest paper “Plant and frugivore species characteristics drive frugivore contributions to seed dispersal effectiveness in a hyperdiverse community”, Mariana describes the delicate relationship between fruit and frugivore, and reminds us of how important seed dispersal services are for many ecosystems (on top of the threats that climate change is creating)! Additionally, Mariana gives us great advice on learning to just let things be – whether in research or just general life as well!
A Portuguese translation of this blog post is available here.
About the paper
We studied the seed dispersal system of one of the most threatened and neglected ecosystems in Brazil: The Cerrado, a species-rich Neotropical savanna that provides a variety of ecosystem services (e.g., water provision). Our main goal with this research was to understand what characteristics plants and frugivores of Cerrado have that make them the most efficient partners to successful seed dispersal (i.e., when a dispersed seed grows into an adult plant). While most of the research available assumes that interactions between plants and frugivores are a good proxy of seed dispersal success, we wanted to look at those interactions in more detail. By linking different plant and frugivore characteristics to estimates of successful seed dispersal, we were able to better understand which plants and frugivores are key to maintaining seed dispersal services that allow the Cerrado plant community to regenerate.
Our field work involved recording interactions between frugivores and plants bearing fleshy ripe fruits using a mix of sampling methods: focal observations, captures with mist nets, and videos recorded with camera traps. Besides recording interactions, we counted the number of fruits being dispersed during frugivore visits to plants, and estimated seed dispersal quality by using seed germination experiments with seeds that passed through the guts of those frugivores. We also recorded plant and frugivore characteristics most likely to affect seed dispersal interactions. For example, fruit and frugivore phenologies were recorded monthly by counting the number of ripe fleshy fruits within 6 plots of 100 x 10 m, and the frugivore abundances were recorded through point counts (for birds) and appearances in camera traps (for mammals). Other characteristics used were frugivore gape and gullet sizes, their degree of frugivory and feeding behaviors, and fruit and seed sizes, all obtained through measures of birds captured, collected fruits and seeds, and/or databases.
About the research
Our main finding was that the most abundant fruits and frugivores occurring simultaneously in space and time were the most important partners to successful seed dispersal events. This is something to be aware of, as we are currently facing extreme climatic events due to global climate change, and the Cerrado is facing severe and prolonged droughts. The impact of those droughts is not yet well studied, but we know climate change is altering plant and frugivore phenologies around the world, with consequences to plant and frugivore interactions. Given the importance of phenological overlap to seed dispersal, extreme climatic events can cause mismatches in fruit and frugivore phenologies, potentially affecting seed dispersal interactions and plant community regeneration in the Cerrado.
I believe the next steps for research on seed dispersal ecology in the Cerrado should aim to understand the role of frugivores on plant recruitment. Also, we should gather more information about large mammals, and their role in dispersing large fruits and providing long-distance seed dispersal, to better comprehend their influence in plant recolonization of wildfire disturbed sites. One of the greatest challenges researchers in this region face, is convincing policy makers and governments about the importance of maintaining and protecting areas of Cerrado. This can help preserve crucial plant-animal interactions, allowing this ecosystem to thrive and continue to provide ecosystem services.
About the author(s):
At the time of writing this blog, I (Mariana) am about to defend my PhD thesis in Ecology and Natural Resources at the Federal University of São Carlos, in Brazil. I have always enjoyed being near nature, and knew I wanted to work with something to animals. I realized this is a bit of a cliche now, but that was the main reason I started the Biological Sciences course at University of São Paulo back in 2011. During this period, I started my first research project under the very good supervision of Alexsander Zamorano Antunes, who taught me the main sampling techniques to record birds and their interactions.
I became more interested in ecology during my masters, after realizing that plant-animal interactions could be used as tools to answer a bunch of interesting ecological questions. I still get very excited whenever I see animals eating fruits in the wild, and hope this feeling never goes away. Currently, I am interested in further exploring the role of different frugivores in seed dispersal by understanding the outcomes of different plant-frugivore interactions to plant recruitment.
This work wouldn’t be what it is, if it wasn’t for the help of my current supervisors and coauthors, Alexander Christianini and Guadalupe Peralta. I was lucky enough to surround myself with the nicest and most competent people that guided me through my scientific journey so far. We come from countries that have faced cuts in science funding, and sometimes we need to get additional financial resources from other countries (shout out to the Rufford Foundation and Neotropical Grassland Conservancy for granting the awards that allowed us to do such amazing science!). Despite those setbacks, we do our best to continue producing high-quality science. If I had to give my younger self a piece of advice, I would say: you cannot control everything, either in research or in life. Sometimes things get out of hand, and although it is certainly very frustrating, you need to learn to let those things go, and focus your energy on what you are able to control.
Like the blog post? Read the research article here.
