Analogous losses of large animals and trees, socio‐ecological consequences, and an integrative framework for rewilding‐based megabiota restoration

Abstract

Large‐sized animals (megafauna) and trees (megatrees) are key ecosystem components with high cultural and economic importance going back millennia. Once common, both groups of megabiota have been massively reduced in pre‐historic and historic times, with human‐induced downsizing still ongoing. Key ecosystem services provided by megafauna and megatrees include nutrient and seed transfer, carbon allocation, climate regulation and biodiversity facilitation. Socio‐cultural services include food and timber provisioning and the ‘charisma’ of large‐sized organisms, with its associated high cultural, recreational and nature conservation values for human societies worldwide. Conservation and restoration of megafauna and—trees in a socio‐ecological framework are needed to counteract past and ongoing analogous downsizing of both groups of megabiota and the loss of important ecosystem services in a human‐dominated world. Importantly, synergistic megatree–megafauna restoration promotes self‐regulating biodiverse ecosystems across the full range of land use intensities ranging from current downsized wildlands to highly human‐modified landscapes. We propose an integrative rewilding‐based restoration framework applicable across the whole range of human land use intensity. This includes individual‐based protection, assisted colonisation and facilitation of urban wildlife. Active management of megafauna and ‐trees can be economically beneficial and necessary to minimize human–wildlife conflicts in highly human‐dominated landscapes. Societal acceptance and adaptation to old big trees and wild megafauna are prerequisites for successful megabiota restoration in human‐modified landscapes and elsewhere where human–wildlife conflicts are hard to avoid. The prime goal of such integrative rewilding activities should be a proactive facilitation of the self‐regulation potential of natural and novel ecosystems for which large‐sized trees and animals would be some of the most important components for enhancing biodiversity and societal value in the Anthropocene. Such megabiota restoration needs to be done on a wide scale to restore functional effects on the biosphere. A free Plain Language Summary can be found within the Supporting Information of this article.

Large trees in tropical rain forests require big plots

“…The most important societal impact of big trees will in the next few years be at the level of global society. We recommend that two things should happen as a result of our study and of others raising awareness of megabiota (Enquist et al., 2020; Schweiger & Svenning, 2020). The first will not be a surprise to this readership that there will be widespread recognition and financial support for the maintenance of big trees for carbon sequestration.…”

“…There is increasing recognition by the scientific community of big trees in discussions on the disproportionate importance of megabiota (the largest plants and animals) for biosphere function (Enquist et al., 2020; Schweiger & Svenning, 2020). In addition to the big trees documented in this study, the Congo Basin is also renowned for its large mammals including forest elephants, western lowland gorillas, forest buffalo, giant forest hogs and chimpanzees.…”

Plants, people and long‐term ecological monitoring in the tropics

“…There has been increasing recent interest in the disproportionate importance of “megabiota”—the largest plants and animals—for ecosystem function (e.g., Enquist et al., 2020; Schweiger & Svenning, 2020). In the tropics, the largest trees are found in tropical rain forests, and the fact that the largest ever trees have been discovered in the past few years in Asian and Amazonian rain forests using remote sensing (Shenkin et al., 2019) indicates that despite the proliferation of permanent monitoring plots in this biome, plots have not been effective in understanding the distribution of the largest trees.…”

“…There has been increasing recent interest in the disproportionate importance of "megabiota"-the largest plants and animals-for ecosystem function (e.g., Enquist et al, 2020;Schweiger & Svenning, 2020).…”

A multi-disciplinary perspective to nuance the narrative of tree planting as a nature-based solution

“…Restoring these factors and processes also ensures that restoration efforts benefit the many species that depend on open-and semi-open habitats (e.g. glades within forests), coarse woody debris and other aspects of ecosystem structure that simple tree planting schemes may overlook (Schweiger and Svenning, 2019).…”