A rejuvenated forest can appear tall, verdant, and thriving. Revived wetlands can teem with buzzing insects and fluttering birds. However, upon closer inspection, scientists have observed that certain minute inhabitants, 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 animal and plant species, facilitating their recovery. Yet, recent studies indicate that not all species return at the same pace. Some of the tiniest, less conspicuous 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 not on the trees but on the minute flowers, mosses, liverworts, and lichens that thrive within them. According to Macdonald, these ecosystems harbor a significantly larger number of species compared to tree species.
While to the casual observer a regrown forest may resemble an untouched one, Macdonald noted a subtle difference in regrown coniferous boreal forests. She emphasized that detecting what might be absent requires systematic data collection.
Macdonald conducted a comprehensive analysis, amalgamating her research with global data to evaluate the recovery of plants and animals in boreal forests post-clearcutting. The study, recently featured in the journal Nature Sustainability, revealed that birch and aspen forests and their inhabitants typically recover within 25 years, whereas conifer forests take significantly longer. In coniferous forests, understory plants, particularly lichens, mosses, and liverworts, may take 85 years or more to reestablish, with some species still unrecovered after a century.
The observed pattern is not exclusive to boreal forests. Researchers studying restored habitats, including wetlands, have also noted the persistence of absent less visible species despite the apparent health of the environment.
Viktoria Wagner, an associate professor at the University of Alberta, describes this decline as a “silent form of loss,” emphasizing that species may not go extinct entirely but vanish from numerous locations where they once thrived. This phenomenon, termed “dark diversity,” has been identified among plants worldwide, including algae, which are taxonomically related to plants.
The absence of certain species may impede ecosystem recovery and have unseen repercussions. Algae, despite their small size, play a vital role in global photosynthesis, influencing oxygen availability and food sources. Wagner emphasizes that as species diversity decreases, it can disrupt ecological balance and negatively impact other organisms.
Understanding these dynamics can guide landscape managers in preserving a broader array of species. Macdonald suggests that selective or partial harvesting in conifer forests, rather than clearcutting, may be more conducive to species preservation.
Algal habitats are also facing threats globally, endangering the biodiversity they support. Michael Melkonian, a German botanist, meticulously collects and preserves algae strains to safeguard their diversity. His efforts, alongside his colleagues, have amassed over 5,000 strains, creating what he calls an “algal zoo” to ensure the preservation of these species.
Wagner asserts that the continual loss of species underscores the necessity of actively intervening to preserve biodiversity by maintaining and restoring sufficient habitat across landscapes. She emphasizes that loss is an ongoing process, requiring proactive measures to sustain species diversity.
In conclusion, the conservation of disappearing species groups demands more than safeguarding isolated habitats; it necessitates the preservation and restoration of suitable habitats for species to persist and thrive across ecosystems.