A regenerated forest can appear tall, vibrant, and verdant. Revived wetlands may teem with insects and fluttering birds. However, upon closer inspection, scientists have noted that some of the smallest inhabitants, such as specific mosses, lichens, algae, and fungi, often remain absent.
While restoring ecosystems like forests and wetlands can aid in rescuing declining species of animals and plants and facilitate their population recovery, recent studies indicate varying rates of return for different species. Certain tiny and less conspicuous residents may remain scarce or missing for extended periods, potentially impacting other species.
Ellen Macdonald, a botanist from the University of Alberta, has dedicated her career to studying forests not just for their trees but for the plethora of tiny flowers, mosses, liverworts, and lichens that thrive in their midst. According to Macdonald, the number of species in these areas far surpasses that of tree species.
Although to the average observer, a regenerated forest decades after logging may resemble an untouched one with tall trees, birds, and insects, Macdonald has observed subtle discrepancies while walking through regrown coniferous boreal forests. She emphasized the necessity of collecting data to discern what might be missing.
Macdonald’s research, combined with global data, examined the timeline for plant and animal reappearance as boreal forests regenerate post-clearcutting. The study, recently published in the journal Nature Sustainability, revealed that birch and aspen forests and their inhabitants typically recovered within 25 years, whereas conifer forests required significantly longer periods. In conifer forests, understory plants, particularly lichens, mosses, and liverworts, took 85 years or more to re-establish, with some species still absent even after a century.
This pattern is not exclusive to boreal forests, as researchers studying wetlands and other restored habitats have observed apparent health alongside the continued absence of less visible species. This phenomenon of “dark diversity” has been noted in various plants worldwide, including algae.
The absence of species can impede recovery and have unseen repercussions. Algae, despite their small size, play a vital role in global oxygen availability and food production. Declining diversity can disrupt ecosystems, affecting other species negatively.
Understanding these dynamics can guide landscape management strategies to preserve more species. Macdonald suggests that selective or partial harvesting in conifer forests, rather than clearcutting, could be beneficial.
In the face of diminishing biodiversity, efforts to safeguard species are crucial. Michael Melkonian and his team have amassed over 5,000 strains of algae to create what he calls an “algal zoo,” ensuring the preservation of these species as living organisms.
To combat ongoing species loss, it is imperative to actively intervene by maintaining and restoring adequate habitats across landscapes to enable species persistence. Preserving biodiversity requires more than protecting isolated habitats—it necessitates comprehensive conservation efforts to sustain species diversity.
