A rejuvenated forest may appear tall, dense, and verdant, while restored wetlands can teem with insects and birds. However, scientists have discovered that some of the tiniest inhabitants, such as specific mosses, lichens, algae, and fungi, are often absent even in these thriving ecosystems.
Restoring habitats like forests and wetlands can aid in the recovery of declining animal and plant species, but research indicates that not all species return at the same pace. Certain minuscule and inconspicuous inhabitants may remain scarce or missing for extended periods, potentially impacting other species.
Ellen Macdonald, a botanist from the University of Alberta, has dedicated her career to studying forests, 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.
Although to the casual observer a regrown forest may seem indistinguishable from an untouched one, Macdonald has noticed discrepancies while walking through regrown coniferous boreal forests. She emphasizes the need for data collection to identify what might be missing in these ecosystems.
Macdonald’s research, combined with global data, has shed light on the timeline for the return of plants and animals in regenerating boreal forests post-clearcutting. The study, recently published in the journal Nature Sustainability, revealed that birch and aspen forests recovered within 25 years, while conifer forests took much longer. Understory plants, particularly lichens, mosses, and liverworts, took 85 years or more to reestablish in conifer forests, with some species still absent after a century.
The phenomenon of missing species is not exclusive to boreal forests. Scientists studying restored wetlands and other habitats have observed similar imbalances, where certain less visible species remain absent despite the overall appearance of health in the ecosystem.
Viktoria Wagner, an associate professor at the University of Alberta, describes this decline as a “silent loss,” where species vanish from once-thriving locations, diminishing overall species diversity. This concept, termed “dark diversity,” has been observed in plant habitats globally, including algae.
The absence of certain species can impede ecosystem recovery and have far-reaching consequences. Algae, for instance, play a crucial role in global photosynthesis, influencing oxygen availability and food sources. Wagner emphasizes that declining diversity can have cascading effects on other species within the ecosystem.
Understanding these patterns can guide landscape managers in preserving biodiversity. Macdonald suggests that selective harvesting or partial clearing of conifer forests could help protect the delicate balance of species within these ecosystems.
Algae habitats worldwide are facing threats, along with the species that inhabit them. Michael Melkonian, a botanist, has been diligently collecting and preserving various algae strains to safeguard their biodiversity. His efforts have resulted in the establishment of an “algal zoo,” a repository of living algae species.
Wagner stresses the importance of actively preserving habitat to prevent ongoing species loss. She advocates for maintaining and restoring sufficient habitat to sustain species diversity across landscapes, emphasizing the need for continuous intervention to safeguard biodiversity.
This article is part of a series focusing on scientists studying disappearing species groups that often go unnoticed. It aims to raise awareness of these species and their ecological significance, highlighting efforts to ensure their survival.