A regenerated forest can appear tall, vibrant, and verdant. Revived wetlands can be abuzz with insects and alive with birds. However, upon closer examination, scientists have discovered that some of the tiniest inhabitants, such as specific mosses, lichens, algae, and fungi, are often still absent.
The restoration of ecosystems like forests and wetlands can aid in the conservation of declining animal and plant species and support their population recovery. Nonetheless, recent studies have revealed that not all species return at the same pace. Certain inconspicuous 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, focusing not on the trees themselves but on the minute flowers, mosses, liverworts, and lichens that thrive in their shadows, among their roots, or on their bark’s textured surfaces.
Macdonald emphasized that the number of species in these areas far exceeds that of tree species. To the casual observer, a regenerated forest several decades post-logging may resemble an untouched one, teeming with tall trees, birds, and insects. However, Macdonald noted a sense of something amiss while walking through regenerated coniferous boreal forests, even if the specific issue was not immediately discernible.
Through a combination of her research and global data, Macdonald investigated the duration it takes for plants and animals to reappear as boreal forests regenerate post-clearcutting. The findings, recently published in the journal Nature Sustainability, indicated that birch and aspen forests and their inhabitants recover within 25 years, whereas conifer forests require significantly longer. In conifer forests, understory plants, particularly lichens, mosses, and liverworts, took 85 years or more to reappear, with some species not recovering within the century of available data.
The delay in species reappearance is not exclusive to boreal forests. Researchers studying wetlands and other restored habitats have observed that while some areas may appear healthy, certain less conspicuous species remain absent. This phenomenon of declining species presence, described as “dark diversity” by Viktoria Wagner, an associate professor at the University of Alberta, has been identified in plant habitats worldwide.
The disappearance of species from specific locations may hinder recovery efforts, as missing species can have unseen repercussions on ecosystems. Algae, for instance, play a crucial role in oxygen availability and global photosynthesis. According to Michael Melkonian, an expert in the field, algae are believed to contribute significantly to global photosynthesis.
Understanding these patterns can guide landscape managers in preserving a greater diversity of species. Macdonald suggests that selective or partial harvesting of conifer forests might be more beneficial than clearcutting, based on the research findings.
Melkonian also highlighted the threat to algae habitats worldwide and the imperative to protect these species. His collection and cultivation of over 5,000 algal strains serve as a living repository to ensure the preservation of these species.
Wagner stresses the importance of maintaining sufficient habitat for species to thrive across landscapes, emphasizing the need for ongoing interventions to combat the continuous loss of species.
In essence, preserving biodiversity goes beyond safeguarding isolated pockets of habitat; it entails sustaining and restoring adequate habitat for species to endure and thrive across the ecosystem.
