ecosystem importance: herbivory's influence (Introduction)

by David Turell , Friday, November 03, 2023, 16:07 (176 days ago) @ David Turell
edited by David Turell, Friday, November 03, 2023, 16:39

All ecosystems are based on vegetation availability:

https://www.sciencemagazinedigital.org/sciencemagazine/library/item/03_november_2023/41...

"Restoring vegetation in degraded ecosystems is an increasingly common practice for promoting biodiversity and ecological function, but successful implementation is hampered by an incomplete understanding of the processes that limit restoration success. By synthesizing terrestrial and aquatic studies globally (2594 experimental tests from 610 articles), we reveal substantial herbivore control of vegetation under restoration. Herbivores at restoration sites reduced vegetation abundance more strongly (by 89%, on average) than those at relatively undegraded sites and suppressed, rather than fostered, plant diversity. These effects were particularly pronounced in regions with higher temperatures and lower precipitation. Excluding targeted herbivores temporarily or introducing their predators improved restoration by magnitudes similar to or greater than those achieved by managing plant competition or facilitation. Thus, managing herbivory is a promising strategy for enhancing vegetation restoration efforts.

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"Our findings offer insights toward achieving myriad restoration commitments. Massive revegetation efforts are being implemented globally, including the Bonn Challenge, Africa’s Great Green Wall, and the Blue Carbon Initiative. By demonstrating global, substantial impacts of herbivores on the abundance and diversity of vegetation under restoration, our study suggests that revegetation efforts, if implemented merely by removing the cause of degradation, recreating abiotic conditions, or planting propagules, are unlikely to achieve maximal outcomes. Rather, substantial improvements can be achieved by comanaging herbivory (by either plant- or consumer-based approaches). By revealing climates and other moderators of variations in herbivore effects at restoration sites, our study can help restoration practitioners pinpoint where and when managing herbivory may be particularly crucial, including in the tropics, where global priority areas for vegetation restoration are concentrated, and in hot, dry regions as well as in the years ahead with respect to future climates. Indeed, as climate change and human activities, which are often beyond the immediate control of local managers, continue to disrupt food webs and affect vegetation through top-down processes, managing herbivory may become increasingly relevant and tractable for enhancing recovery and resilience.

Comment: all of Earth is covered by ecosystems based on vegetation, eaten by herbivores who are eaten by carnivores. All in a neat balance. And all provides human food, which is not in balanced supply at this time. That is why these studies aerev so important.

Another review emphasizes main points:

https://mail.google.com/mail/u/0/#inbox/FMfcgzGwHVPSSpjSNmWLvBGwQPrpDrJJ

"Restoration projects around the world aim to rectify the damage people have done to the planet’s ecosystems. But while they often prevent further habitat losses, they’re not so great at actually bringing back wild spaces. According to a new survey of almost 2600 restoration projects published in this week’s issue of Science, there’s one thing that these projects mostly neglect that could more than double plant regrowth: bringing back ecosystem predators.

"The team’s meta-analysis revealed that hungry herbivores are one of the main barriers to restoration success—yet only 10% of the projects examined included any means of limiting their damage. And that, the authors found, is where predators shine. While excluding plant-eaters roughly doubled the amount plant life that grew at a site, introducing predators increased vegetation abundance by a whopping 372% for projects involving planting native species. (my bold)

“'If we want more plants, we have to let more predators in or restore their populations,” study coauthor Brian Silliman says in a press release. “It’s like learning a new gardening trick that doubles your yield.'”