Together with researchers at Vrije Universiteit Brussel, a postdoctoral researcher at the University of Maryland (UMD) recently co-published a large-scale study examining the genetic diversity of mangroves over 1,800 miles of coastline in the ocean. West Indian, including East Africa. and several islands. While the mangroves of Asia, Australia and the Americas have been studied in more depth, little work has been done to classify and demonstrate the genetic diversity of African mangrove populations for conservation purposes. Similar to other wetlands, mangrove trees like the species studied in the new article in Scientific reports (Rhizophora mucronata) create habitats for a myriad of animals and plants, acting as biodiversity hubs while economically supporting many local communities. This work shows how ocean currents create both connectivity and barriers between mangrove populations, with important implications for how to protect these ecosystems.
“Whenever I am asked about mangroves, I always say they are my happy place,” says Magdalene Ngeve, postdoctoral researcher at UMD in Maile Neel’s lab (professor in the Department of Plant Science and of Landscape Architecture and Department of Entomology). “These are very fascinating systems to work with. When I went to do my fieldwork for my masters thesis and got to experience mangroves, be near trees and see how much biodiversity they harbor, I immediately fell in love and I knew it. should i study. “
Born and raised in Cameroon, Ngeve grew up near the coast, but didn’t give much thought to her local mangroves until she left to continue her graduate studies on a scholarship at Vrije Universiteit Brussel. After studying zoology for her undergraduate work, Ngeve became a biologist with a specialization in environment, biodiversity and ecosystems for her masters and conservation ecology and genetics for her doctorate. This is where her love of mangroves blossomed, and she brought that passion with her to UMD as a Presidential Postdoctoral Fellow.
“I am so excited that we published this study, with the collaboration of mangrove experts in Brussels [Belgium] and in the world, “says Ngeve.” In conservation we have limited resources to manage everything on the planet, so we are talking about these important evolutionary units, which are units that we should focus on to preserve so much genetic variability. as possible in order to preserve their evolutionary potential and ensure the resilience of the ecosystem. This work has shown us that we actually have even more distinct populations than we thought, and that’s important for conservation. “
As Ngeve explains, people don’t often think of ocean currents as a way to propagate seeds and seedlings (called propagules), or even pollen. But for many species water is the primary means of seed dispersal and diversity is assured. “Ocean currents can be genetic barriers, and at the same time they can be facilitators of genetic connectivity,” says Ngeve. “It just depends on how they come together and connect. In this study, we saw that ocean current patterns maintain genetic diversity in remote island populations like the Seychelles and cause genetic diversity to build up around the equatorial current. South [near the equator] splits near the East African coast. The populations of Seychelles and Madagascar probably arose as a result of ancient dispersal events from present-day Australia and Southeast Asia, and these island populations act as an important springboard in the dissemination of the diversity on the East African coastline, which we found to be a much younger population. Dividing currents also create a barrier to genetic connectivity between neighboring populations to the north and south of the East African coast and the Mozambique Channel. “
This study fills an important research gap, as African mangroves, especially genetic aspects, have been under-studied according to Ngeve. For his doctoral work, Ngeve presented some of the early genetic work on the mangroves of the West African coast, so this extension work to the East African coast is a natural next step. By locally understanding the genetic diversity of these species, researchers can make connections between populations for global conservation.
Ngeve is particularly interested in coastal environments, or the intersection of land and sea as a means of looking at broader global change phenomena. “Almost everything we do on land affects the ocean, and these mid-environments are like the bridge,” says Ngeve. “We talk a lot about climate change and rising sea levels, coasts and estuaries. [like the Chesapeake Bay and Hudson River Estuary] are on the front line. How do species in these ecosystems survive and adapt? Fundamental species like mangroves and submerged aquatic vegetation, which I also study as a post-doctorate, are home to so many species and are home to great biodiversity. Ensuring their resilience means protecting this biodiversity for all those who depend on it. “
Ngeve is also reflecting on how humans depend on mangroves and hopes to find ways for rural communities in his home country of Cameroon to protect mangroves while providing for their families. Through her start-up project called BeeMangrove, she hopes to shift locals from overexploitation of mangroves for timber as a livelihood to raising honey bees that can simultaneously help pollinate mangroves and produce honey for sale. .
“When studying the Rhizophora racemosa mangrove species which is pollinated by both wind and insects, I observed that mangroves more exposed to the wind produced more seedlings. Based on my genetic work, I also observed pollination limits at the study sites. pollination problem in mangroves that don’t get the wind, ”says Ngeve. “At the same time, there are also mangrove markets where people only sell mangrove wood, and logging is a problem. There is no doubt that mangroves like other ecosystems are in decline, and we are losing so much biodiversity. In rural Cameroon, I began to wonder what these people could do differently. But they depend exclusively on mangroves for their livelihood. That’s all they have for food, they collect the wood to build their houses and sell it to support their families and send their children to school – the mangroves are everything to them. How do you tell people who are so dependent on the system to stop logging? You have to offer them an alternative. “
Ngeve hopes that with future funding, BeeMangrove can be that alternative. She is currently examining perceptions of mangroves in Cameroon. She worked with local organizations to provide education and awareness to communities, and the first beehive was installed. The objective is to work with the inhabitants from the start to steer and develop this program with their support.
Having grown up in Cameroon, this project is very personal for Ngeve. She is grateful for all of her family’s support as a researcher. “My mother became a mangrove researcher herself, looking after my young mangrove plants even after my growing experience ended,” she says. His father, Jacob Ngeve, was in fact a doctoral student in 1988 from the Department of Plant Sciences and Landscape Architecture at UMD (then Department of Horticulture). As a quantitative plant breeder, he had an international career as an agricultural researcher, and his influence continues in his work to this day.
“Growing up in Africa, I remembered seeing pictures he would send of himself to those same walls at the College of Agriculture and Natural Resources,” Ngeve says. “I never imagined I would be here one day – it’s a real privilege. My father always told me, ‘Education is the only thing a father can give his child, because no one can take it away from you. ‘And that meant so much to me because I clung to those words, and against all odds, I studied and followed my dreams. I can’t wait to make an impact here like he has. “
Ngeve is also incredibly grateful for the mentorship she received on her way to this job and to UMD, from Neel as current mentor, to those in Brussels, to her family. “My mentors are the reason I’m here, and I can’t wait to pay for everything they’ve put in me.”