A rejuvenated forest can present itself as tall, vibrant, and verdant. Reinstated wetlands can hum with insects and flutter with birds. However, upon closer inspection, scientists have discovered that some of the tiniest inhabitants, such as specific mosses, lichens, algae, and fungi, are often conspicuously absent.
The restoration of ecosystems like forests and wetlands can aid in preserving declining species of animals and plants and fostering their recovery. Nonetheless, recent studies indicate that not all species return at the same pace. Some of the smallest and least conspicuous inhabitants may remain scarce or missing for extended periods, potentially impacting other species.
Ellen Macdonald, a botanist at the University of Alberta, has dedicated her career to studying forests, albeit not primarily focusing on trees. Instead, she concentrates on the minute flowers, mosses, liverworts, and lichens that thrive in the shadow of trees, among their roots, or on the textured surfaces of their bark.
Macdonald emphasized the vast diversity of species in these ecosystems, surpassing that of tree species. While to the casual observer, a reforested area a few decades post-logging may appear similar to an untouched forest, Macdonald noted a subtle sense of incongruity while traversing regenerated coniferous boreal forests.
To discern the missing elements, detailed data collection is imperative, according to Macdonald. Drawing on her research and global data, she investigated the timeline for the reestablishment of plants and animals as boreal forests regenerate post-clearcutting.
The study, recently published in the journal Nature Sustainability, revealed that birch and aspen forests and their inhabitants seem to recover within 25 years, whereas conifer forests require significantly more time. Particularly in conifer forests, understory plants, especially lichens, mosses, and liverworts, took 85 years or more to reappear, with some species still not recovered after a century of observation.
The phenomenon of delayed recovery is not exclusive to boreal forests. Researchers studying wetlands and other restored habitats have also observed a similar trend, where some less visible species remain absent despite the apparent health of these ecosystems.
Viktoria Wagner, an associate professor at the University of Alberta, described this decline as a “silent form of loss,” where species may not go extinct entirely but vanish from many former habitats, reducing species diversity at individual sites.
Wagner’s concept of “dark diversity” highlights the disappearance of species from specific locations, potentially leading to local extinction. She emphasized the challenges of landscape restoration, noting that success is not guaranteed and can be complex.
Understanding these recovery patterns can guide landscape managers on preserving more species. Macdonald suggested selective harvesting or partial removal in conifer forests rather than clearcutting, based on the research findings.
The repercussions of missing species may not be immediately evident. Algae, despite their small size, play a significant role in global oxygen availability and food production. The decline in diversity of species can have cascading effects on ecosystems, negatively impacting other species.
Preserving biodiversity requires more than safeguarding isolated habitats; it necessitates maintaining and restoring adequate habitat for species to thrive across the landscape. Active interventions are crucial to counteract ongoing species loss and preserve ecosystem balance.
In efforts to conserve these species, researchers like Michael Melkonian have collected and cultivated thousands of algal strains to safeguard their existence. Melkonian referred to their collection as an “algal zoo,” serving as a repository for these species as living organisms.
The series of articles highlights the work of scientists investigating vanishing species groups that have a significant impact on our lives. It underscores the importance of understanding these species and implementing strategies to ensure their continued existence.