To Restore Ecosystems, Think About Thwarting Hungry Herbivores

A recent comprehensive study delving into nearly 2,600 ecosystem restoration projects globally reveals a critical oversight: the majority of these initiatives fail to account for the threat posed by herbivores, animals that eat plants, to newly planted vegetation. Led by Brian Silliman, a distinguished professor at Duke University, the survey indicates that a mere 10% of restoration projects actively address or control herbivores, despite their tendency to view early-stage plants as delectable treats.

The study highlights a missed opportunity in the restoration process. While these projects typically focus on excluding competing plant species, they neglect the impact of herbivores on vulnerable early-stage plants. Silliman emphasises that not safeguarding these plants during their initial growth stages results in a substantial missed opportunity to expedite restoration, enhance its outcomes, and reduce associated costs.

The research underscores the effectiveness of protective measures during the early stages of plant growth. Installing barriers or introducing predators to manage herbivore populations can lead to a significant increase in plant regrowth, ranging from 100% to 400%. Strikingly, these gains surpass the benefits achieved by excluding competing plant species. Silliman questions the underutilization of such strategies, suggesting that prioritising plant protection during their vulnerable early phases could yield considerable advantages.

The collaborative effort involved an international team from 20 universities and institutions, emphasising the global relevance of herbivores in vegetation restoration, especially in the context of climate change. The study identifies regions with higher temperatures and lower precipitation as particularly susceptible to the effects of herbivores.

In essence, the study concludes that if the goal is to foster more plant growth, there is a need to either allow more predators into ecosystems or restore their populations. Silliman suggests that the decline of large predators, such as wolves, lions, and sharks, which normally regulate herbivore populations, could be a significant factor contributing to heightened grazing pressures. While conventional restoration methods have been effective in slowing losses, they fall short in expanding vegetation, and the challenges posed by climate change further complicate the restoration landscape.

Silliman proposes a paradigm shift in restoration approaches, advocating for the untapped potential of leveraging predators to control herbivores at restored sites. This innovative approach, likened to discovering a new gardening trick that doubles yield, holds promise for expediting the restoration of crucial ecosystems essential for human and environmental health.

SOURCE:

Duke Environment. https://nicholas.duke.edu/news/restore-ecosystems-think-about-thwarting-hungry-herbivores