A rejuvenated forest can present a vibrant and dense appearance, while restored wetlands can be bustling with insects and birds. However, a closer examination by scientists reveals that some of the tiniest inhabitants, such as certain mosses, lichens, algae, and fungi, are often still absent.
Efforts to restore habitats like forests and wetlands can aid in saving declining species of animals and plants and facilitate their recovery. Yet, 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 extended periods, potentially impacting other species.
One botanist, Ellen Macdonald from the University of Alberta, has dedicated her career to studying forests, focusing on the myriad of small flowers, mosses, liverworts, and lichens that thrive within them. She emphasizes that the diversity of these smaller species far exceeds that of the tree species present.
Macdonald’s research, combined with global data, has shed light on the timeline for plant and animal reestablishment in boreal forests following clearcutting. A recent study published in the journal Nature Sustainability revealed that birch and aspen forests recovered within 25 years, whereas conifer forests took significantly longer. In conifer forests, understory plants like lichens, mosses, and liverworts required 85 years or more to reappear, with some species still absent after a century.
This pattern of slow recovery is not unique to boreal forests but is also observed in wetlands and other restored habitats. German botanist Michael Melkonian’s observations in southern Germany highlighted the incomplete recovery of wetlands decades after restoration efforts, where numerous species, particularly algae, were missing.
The decline of certain species, termed “dark diversity” by biologist Viktoria Wagner, represents a silent form of loss, with species disappearing from various habitats worldwide. This loss can have cascading effects on ecosystems, impacting the availability of oxygen and food sources.
Understanding these recovery patterns can guide landscape managers in preserving more species, suggesting selective harvesting rather than clearcutting in conifer forests. Preserving biodiversity requires active interventions to maintain and restore sufficient habitat across landscapes for species to persist.
In efforts to preserve algae species facing threats globally, Melkonian and his colleagues have collected and cultivated over 5,000 strains, creating an “algal zoo” to ensure the preservation of these species. Wagner emphasizes the need for continuous efforts to protect biodiversity by maintaining and restoring habitats for species to thrive across landscapes.