A regenerated forest can appear tall, vibrant, and verdant. Revived wetlands can hum with insects and flutter with birds. However, upon closer inspection, scientists are discovering that some of the tiniest inhabitants, including specific mosses, lichens, algae, and fungi, are often still absent despite habitat restoration efforts.
Rehabilitating ecosystems like forests and wetlands can aid in conserving declining species of animals and plants and facilitating their population recovery. Nevertheless, 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 from the University of Alberta, has dedicated her career to studying forests, focusing not on the trees but on the minute flowers, mosses, liverworts, and lichens that thrive in their midst. Macdonald emphasizes that the diversity of these small species far exceeds that of tree species.
To the untrained eye, a reforested area several decades after logging may resemble an untouched forest, filled with tall trees, birds, and insects. However, Macdonald has observed discrepancies while traversing regrown coniferous boreal forests, sensing that something was amiss, even if not immediately identifiable.
Macdonald conducted thorough research, combining her own findings with global data to analyze the recovery timeline of plants and animals following clearcutting in boreal forests. The study, recently featured in the journal Nature Sustainability, revealed that birch and aspen forests and their inhabitants may recover within 25 years, whereas conifer forests require significantly longer. In conifer forests, understory plants, especially lichens, mosses, and liverworts, may take 85 years or more to reestablish, with some species still not recovered after a century.
The phenomenon of delayed recovery is not exclusive to boreal forests. Scientists studying restored wetlands and other habitats have encountered situations where despite looking healthy superficially, some less visible species remain absent, indicating a silent form of loss.
Viktoria Wagner, an associate professor at the University of Alberta, refers to this decline as “dark diversity,” where species may vanish from numerous locations they once inhabited, reducing species richness at individual sites. Wagner’s research has demonstrated the presence of dark diversity among plants worldwide.
The absence of certain species can hinder ecosystem recovery and have cascading effects on other organisms. Algae, though small, play a significant role in oxygen availability and food production globally. Loss of diversity among species can disrupt ecosystem functioning and impact various organisms negatively.
Understanding these patterns can guide landscape managers in preserving more species. Macdonald suggests that selective harvesting or partial cutting in conifer forests could help maintain biodiversity. For Melkonian, the threats faced by algae habitats worldwide underscore the importance of preserving these species and their environments.
Efforts such as Melkonian’s work in collecting and preserving algae strains contribute to safeguarding biodiversity. Wagner emphasizes that protecting biodiversity requires more than safeguarding isolated habitats, stressing the need to maintain and restore adequate habitat to support species across landscapes actively.
The ongoing loss of species underscores the necessity for continual intervention and preservation efforts to sustain biodiversity.
