A regenerated forest can appear tall, vibrant, and verdant. Revitalized wetlands can teem with insects and flutter with birds. However, upon closer inspection, scientists have discovered that some of the tiniest inhabitants, including specific mosses, lichens, algae, and fungi, are often still absent.
The restoration of habitats like forests and wetlands can aid in preserving declining species of animals and plants and facilitating their recovery. Yet, 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 decades, potentially impacting other species.
Ellen Macdonald, a botanist at the University of Alberta, has dedicated her career to studying forests, focusing not only on the trees but also on the minute flowers, mosses, liverworts, and lichens that thrive in their shadows or on their bark’s textured surfaces.
According to Macdonald, the biodiversity of these smaller species far surpasses that of tree species. While to the casual observer, a regenerated forest may resemble an untouched one with tall trees, birds, and insects, Macdonald has discerned subtle discrepancies during her walks in regrown coniferous boreal forests.
In her research, Macdonald combined her findings with global data to analyze the timeline for plants and animals to reestablish in boreal forests following clear-cutting. The study, recently published in the journal Nature Sustainability, revealed that while birch and aspen forests and their inhabitants recovered within 25 years, conifer forests required a significantly longer period. In conifer forests, understory plants, particularly lichens, mosses, and liverworts, took 85 years or more to reappear, with some species still absent even after a century.
The delay in species recovery is not exclusive to boreal forests. Researchers studying restored wetlands and other habitats have observed a similar phenomenon where certain less visible species remain missing despite the overall appearance of health in the ecosystem.
German botanist Michael Melkonian shared his observations from wetlands near his village in southern Germany, which had been restored and replanted decades after being drained for industrial activities. While the wetlands appeared visually appealing and supported wildlife, Melkonian noted a significant decline in algae diversity compared to his previous research.
Associate Professor Viktoria Wagner emphasized the concept of “dark diversity,” showcasing evidence of species disappearing from habitats worldwide. The absence of certain species could impede ecosystem functions and have repercussions on other organisms.
The loss of species, even the seemingly inconspicuous ones, could have far-reaching consequences. Algae, for instance, play a crucial role in global photosynthesis, impacting oxygen availability and food chains. Maintaining biodiversity is essential for ecosystem stability and resilience.
Understanding these recovery patterns can guide landscape management practices to preserve species diversity. Macdonald suggested a more selective or partial harvesting approach for conifer forests to safeguard the habitat for mosses, lichens, and other understory plants that rely on shade and mature trees.
Melkonian highlighted the threat to algae habitats worldwide and the importance of preserving these often overlooked species. By collecting and cultivating diverse algae strains, researchers aim to create a repository of living organisms to safeguard their survival.
Wagner stressed the continuous need for active interventions to preserve biodiversity and maintain habitats across landscapes. Efforts to protect species and their habitats are vital for sustaining ecosystems and preventing irreversible losses.
This narrative sheds light on the critical work of scientists studying imperiled species groups and underscores the importance of conservation efforts to safeguard biodiversity for future generations.