A rejuvenated forest can appear tall, vibrant, and verdant. Revitalized wetlands can hum with insects and flutter with birds. However, upon closer inspection, scientists have observed that some of the smallest residents—such as specific mosses, lichens, algae, and fungi—are often absent.
The restoration of ecosystems like forests and wetlands can aid in the conservation of declining species of animals and plants, facilitating their recovery. Yet, recent studies indicate that not all species return at the same pace. Some of the tiniest, 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, particularly focusing on the minute flowers, mosses, liverworts, and lichens that thrive in their midst. According to Macdonald, the diversity of these species far surpasses that of tree species.
While to the average observer a regenerated forest post-logging may resemble an untouched one, brimming with tall trees, birds, and insects, Macdonald noted an underlying sense of something amiss during walks through regrown coniferous boreal forests. She emphasized that true observation of missing elements necessitates data collection.
Macdonald’s research, combined with global data, scrutinized the duration for plants and animals to reestablish in boreal forests post-clearcutting. The study, recently featured in the journal Nature Sustainability, disclosed that birch and aspen forests and their inhabitants seemed to recover within 25 years, whereas conifer forests required a much longer duration. In conifer forests, understory plants—especially lichens, mosses, and liverworts—took 85 years or more to return, with some species still unrecovered after a century of available data.
The phenomenon extends beyond boreal forests, as researchers exploring restored habitats like wetlands have encountered healthy-looking environments harboring absent less visible species. This silent form of loss, as described by Viktoria Wagner, an associate professor at the University of Alberta, does not equate to total extinction but signifies the disappearance of species from numerous previous habitats, reducing species richness at individual sites.
The decline in species can have unseen repercussions. Algae, despite their small size, significantly influence global oxygen availability and food supply. Similarly, the reduction in diversity can cause a ripple effect, negatively impacting other species within the ecosystem.
Understanding these patterns can guide landscape managers on preserving more species. Macdonald suggests that selective or partial harvesting of conifer forests could be a more species-conserving approach compared to clearcutting.
Algae habitats, according to Melkonian, are globally imperiled, endangering the survival of their inhabitants. Preserving biodiversity entails not only safeguarding isolated pockets of habitat but also ensuring sufficient habitat for species to persist across the landscape.
Efforts to preserve algae species involve meticulous collection and cultivation, amassing over 5,000 strains to create an “algal zoo” repository. Wagner emphasizes the continuous need for active interventions to counter the ongoing loss of species and maintain biodiversity across landscapes.