A rejuvenated forest can appear tall, dense, and verdant. Revitalized wetlands can hum with insects and flutter 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 saving declining species of animals and plants and assist in their recovery. Nonetheless, recent studies indicate that not all species return at the same pace. Some of the smallest and least noticeable 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 shadows, among their roots, or on the textured surfaces of their bark.
According to Macdonald, the biodiversity in these areas surpasses that of tree species by a significant margin. While to the ordinary observer a regenerated forest decades after logging may resemble one untouched by human activity, Macdonald has sensed a discrepancy while walking through regrown coniferous boreal forests.
Combining her research with global data, Macdonald conducted a study to examine the duration required for plants and animals to return as boreal forests regenerate post-clearcutting. The findings, published recently in the journal Nature Sustainability, suggest that birch and aspen forests and their inhabitants recover within 25 years, whereas conifer forests take considerably longer.
In conifer forests, understory plants, especially lichens, mosses, and liverworts, took 85 years or more to reestablish, with some species still not recovered after a century of available data.
The phenomenon of certain less visible species remaining absent despite the apparent health of restored habitats is not exclusive to boreal forests. Researchers studying wetlands and other rehabilitated ecosystems have encountered similar situations.
Viktoria Wagner, an associate professor at the University of Alberta, characterizes this form of decline as “dark diversity,” where species vanish from numerous locations where they once thrived, leading to a reduction in the species richness at individual sites.
The loss of these species can have unseen consequences. Despite their small size, algae play a vital role in global photosynthesis and ecosystem functioning. Declining diversity can have cascading effects, negatively impacting other species.
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 beneficial approach than clearcutting.
The preservation of biodiversity necessitates more than safeguarding isolated pockets of habitat; it involves maintaining and restoring adequate habitat for species to persist across landscapes. Active interventions are essential to combat the continuous loss of species.
Efforts such as Melkonian’s collection and cultivation of over 5,000 algal strains serve as a means to preserve these species. Establishing a repository of living organisms can aid in safeguarding their existence in the face of ongoing threats.
The widespread loss of species underscores the importance of proactive measures to conserve biodiversity. It is crucial to recognize the significance of these often-overlooked species and take action to ensure their continued presence in our ecosystems.