According to the World Resources Institute (WRI), the world lost 4.1 million hectares of tropical rainforest in 2022 alone - equivalent to losing 11 football fields of forest every minute. While global efforts in reforestation are growing, they are not keeping pace with deforestation rates. For every hectare of forest restored, 10 hectares are lost to deforestation. This alarming disparity underscores the urgent need for more effective and sustainable approaches to forest restoration.
We often take trees for granted and don’t recognize how dependent we are on the entire plant kingdom to provide us with basic needs like food, clothing, and shelter. However, reforestation using hand planting is a slow and expensive endeavor. Recent news has highlighted drone seeding as a promising solution for large-scale forest restoration. Even with drone-based seeding, though, reforestation projects are facing significant hurdles, with 0-20% seed survival seen in recent pilot projects. There is an urgent need to integrate science, technology, and innovation to address one of the most pressing issues in restoration efforts: why are the seeds dying?
Why failing seeds threaten reforestation efforts
Drone-based reforestation, in which flying drones scatter seeds over a landscape, has emerged as a promising and scalable method of seed planting. However, failed reforestation efforts due to seed mortality waste resources and erode trust in these critical initiatives. For communities relying on restored ecosystems, the failure of saplings to establish can mean continued environmental degradation and economic hardship.
Why drone-planted seeds often fail to grow
Current studies show that up to 80% of seeds and seedlings fail to survive, with the highest mortality occurring during the transition from seedling to sapling. Environmental factors such as frost and drought, and biotic factors like competition with other plants and herbivory by wild and domestic mammals, are among the reasons for failed reforestation efforts. Drone-based aerial seeding often fails to place seeds in suitable microenvironments, as seeds are often scattered on inhospitable surfaces. Additionally, the massive firing of seeds of a single plant species from drones can deplete local seed stocks and risk harming local biodiversity.
Artificial seed coatings, designed to protect seeds from threats and enhance their germination, frequently fall short in field tests. Many of these artificial coatings are composed of proprietary chemical mixtures, and their ecological impacts are poorly understood. For example, some substances used in coatings have been found to harm animal health.
Can plants help us build better seeds?
Luckily, forests have extraordinary recovery abilities after disruptions, and even the slightest opportunity can lead to remarkable regeneration. Perhaps we should ask: How do plants overcome environmental challenges in seed dispersal and survival on their own? One of the most critical parts of a plant’s life cycle is seed dispersal, in which it must spread its offspring into new, hospitable sites that will allow them to grow and thrive. Plants have evolved ingenious ways to spread their seeds, ensuring their survival in diverse environments.
To help develop smarter strategies for forest restoration, we are studying the mechanisms by which different plants build structures that aid seed dispersal and survival, and thinking about how these might be adapted to other species that lack these structures. In this work, we are collaborating with the group of Dr. Isabella Fiorello, a professor at Freiburg University who is an expert in plant-based robotics. By providing alternatives to the current practice of mass seed dispersal by drones, we aim to help place seeds in the most suitable microsites for establishment.
How mucilage helps seeds survive in the wild
For example, we were intrigued by the fact that the seeds of some plants have natural coatings that swell rapidly upon hydration. This adaptation allows them to endure harsh environments and wait for an ideal time to germinate. The rapid swelling produces a gel layer called mucilage around the seed that serves several functions, including hydration, anchoring to the soil, and protection from predation. We are studying the complex 3D networks of these mucilage-based gels, which show species-specific differences in their composition and construction.
We are currently exploring the use of mucilage as a natural seed coating with hydrogel-like properties, comparable to but more bio-friendly than the artificial coatings used to enhance seed survival and germination. We came up with the idea to use mucilage from one species as a seed coating in non-mucilage-producing plants and have begun investigating formulations that combine coat-formation, payload encapsulation, anchorage, and water retention to enhances seed germination and biodegradability. This bio-inspired approach is rooted in the principles of soft robotics, and we ultimately aim to develop smart seed-coating technology that might even allow seeds to move autonomously across environments to find favorable planting location, as already happens in a few plant species.
What’s next: testing smarter seeds in the field
We are optimistic about the potential of our research to enhance reforestation projects. Once we have developed our nature-inspired seed coatings, we plan to conduct field tests involving drone-based deployment of native seeds with our coatings on degraded forestland owned by Penn State in Stone Valley. We will monitor whether our biomimetic seed coatings can address key bottlenecks in reforestation: seed survival, establishment, and ecological safety. Scaling this technology could help transform degraded lands into thriving ecosystems, benefiting both wildlife and communities.
Smarter seeds, stronger forests
Reforestation is more than just planting trees—it’s about ensuring that those trees survive and thrive. By leveraging plant biology, precision technology, biomimetic innovation, and ecological insights, we can help overcome the challenges of seed and sapling mortality. If this research takes root, the possibilities are endless. Together, we can turn the tide toward a greener, healthier home for all species, one seed at a time.
Anuleka Dutta is a doctoral student in the Department of Biology at the Eberly College of Science, where she studies plant cell wall applications. As a member of the Anderson Lab, Anuleka combines cell biology and biophysics to study plant cell wall mechanics and is currently developing biohybrid robotic systems using sustainable materials to improve reforestation success. Outside of the lab, Anuleka is passionate about science communication and enjoys sharing plant science stories with broader audiences.
Charles Anderson is a professor of biology and an IEE Fellow who studies plant cell wall dynamics, with the goal of informing efforts to produce sustainable food, materials, and bioenergy from plants.
