A rejuvenated forest may present as tall, verdant, and vibrant. Similarly, revitalized wetlands can teem with insects and birds. However, upon closer inspection, scientists have discovered that some of the tiniest inhabitants, such as specific mosses, lichens, algae, and fungi, are often absent.
The restoration of ecosystems like forests and wetlands can aid in safeguarding dwindling species of animals and plants, facilitating their recovery. Nevertheless, recent studies indicate that not all species return at the same pace. Certain minuscule, less conspicuous 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 the study of forests, particularly focusing on the minute flowers, mosses, liverworts, and lichens that thrive in their midst. She emphasizes that the diversity of these smaller species far surpasses that of tree species.
While an average observer might perceive a regrown forest post-logging as resembling an untouched one, Macdonald noted a sense of unease in regrown coniferous boreal forests. She emphasized the importance of data collection to discern what might be lacking in these habitats.
Macdonald’s research, combined with global data, scrutinizes the duration required for plants and animals to reestablish in boreal forests following clearcutting. The findings, recently published in the journal Nature Sustainability, reveal that birch and aspen forests and their inhabitants recover within 25 years, whereas conifer forests take considerably longer. In conifer forests, understory plants, notably lichens, mosses, and liverworts, may take 85 years or more to reappear, with some species failing to recover even after a century.
The phenomenon observed in boreal forests is not exclusive, as scientists studying restored wetlands and other habitats have encountered a similar disparity. Despite outward appearances of health, certain less visible species may remain absent.
Viktoria Wagner, an associate professor at the University of Alberta, describes this decline as a “silent form of loss,” where species gradually vanish from once-inhabited areas, diminishing overall biodiversity. This phenomenon, termed “dark diversity,” has been observed among plants worldwide, including algae.
The absence of species can impede ecological recovery, as these organisms play crucial roles in maintaining ecosystem balance. Algae, for instance, significantly contribute to global photosynthesis. Wagner emphasizes that declining diversity can have cascading effects, negatively impacting other species within the ecosystem.
Understanding these patterns can guide landscape managers in conserving more species. Macdonald suggests that selective harvesting or partial removal of conifer forests could aid in preserving biodiversity.
Algae habitats worldwide, along with their resident species, face threats. Michael Melkonian, a botanist, underscores the importance of preserving these often-overlooked organisms, likening their collection efforts to maintaining an “algal zoo” to ensure the survival of diverse species.
The ongoing loss of species underscores the necessity of actively preserving biodiversity by maintaining and restoring adequate habitats across landscapes. Wagner advocates for continuous interventions to counteract the perpetual process of species loss.
