Ecosystem Restoration in an Uncertain World: the Role of Regenerative Agriculture and Small Farms

Bonnie Grace Waring^*

• Imperial College London, London, United Kingdom

There is no doubt that ecosystem restoration needs to be accelerated over the next decade to mitigate climate change and stem biodiversity loss. Recent commitments like the New York Declaration on Forests (2014), the Glasgow Leaders' Declaration on Forests and Land Use (2021), and the United for Our Forests Pact (2023) all set ambitious targets to slow down or even reverse loss of crucial habitats by 2030. That key benchmark is only five years away, yet deforestation-related carbon emissions have actually increased in the decade since some of these agreements were signed.1 Meanwhile, in order to meet Rio Convention targets, financial investments in the protection and restoration of ecosystems would need to triple by 2030.2 In some senses, the future of the natural world has never seemed so uncertain. Society will likely soon breach the 1.5°C warming target,3 loss of natural capital is accelerating,4 and political will to confront these issues seems to be waning – at least in some of the large economies that are most responsible for the decline of nature. Perhaps most emblematic of this trend is the withdrawal of the United States of America from the Paris Agreement on climate change mitigation, accompanied by Congressional proposals to sell hundreds of millions of acres of protected public lands. In Europe, the recent adoption of the Nature Restoration Directive is highly encouraging, but progress will likely be stymied by agricultural policies at odds with the mandate for large-scale restoration.5 The maturing science of restoration ecology offers some glimmers of hope, however. Small-scale restoration projects, led by the local communities most invested in their outcome, can have transformative impacts at the global scale. One recent study estimated that smallholder farms (less than 2 hectares in size) – which produce over a third of the world's food6 – could enable the restoration of over 500 million hectares of land at low cost, primarily by increasing tree cover on cropland and pasture.7 Increasing tree cover in agricultural landscapes can have substantial positive impacts on biodiversity, because well-managed farms can both harbour diverse species assemblages within their borders, and connect fragments of intact habitat across the landscape.8 Many of the barriers to realising this enormous restoration potential are linked to governance: strong public institutions which support smallholders' land rights are necessary to ensure the future of restored ecosystems. However, other challenges can be surmounted through new innovations in restoration ecology and agroecology, which reflect our maturing understanding of ecological interactions across scales. Putting these new restoration tools and techniques in the hands of farmers may propel lasting changes in the way land is used, with positive outcomes for biodiversity and the climate. How regenerative agriculture can power restoration in the wider landscape The concept of regenerative agriculture is tightly linked to ecological restoration. It is distinguished from other forms of sustainable agriculture (e.g. organic farming) by its focus on '[adoption of] measures that implicitly drive the regeneration of soils, forests, watercourses, and the atmosphere.'9 Practitioners of regenerative agriculture thus tend to eschew conventional agricultural inputs (e.g. synthetic fertilizers, biocides) in favour of cover crops, organic fertilizers, and microbial inoculants to restore the structure and biodiversity of the soil.10 Many of these farming practices have been shown to enhance biodiversity of arthropods, birds, mammals, and microbes, although not all interventions impact all of the aforementioned groups.11 However, these gains in biodiversity may come at a cost to the farmer, if the adoption of measures to enhance on-farm biodiversity reduces crop yields.12 To solve this conundrum, the research community can take inspiration from family farmers. Nearly a third of small farms worldwide are thought to utilize some agroecological practices,13 and such farms are important sources of innovation. As one example, the smallholder-led Andhra Pradesh Community Managed Natural Farming project in India has developed bespoke crop biostimulants from cow dung and urine, allowing them to maintain high crop yields without relying on conventional inputs that have deleterious environmental impacts.14 Achieving 'win-win' outcomes like this will often involve highly localized solutions that are specific to the farming system under consideration. However, biodiversity is also positively affected by the complexity of entire agricultural landscapes.15 This suggests that biodiversity benefits are an emergent property of landscapes where individual farms exhibit variation in the type, sequence, or management of the crops grown.8 Metacommunity theory, community assembly theory, and a better understanding of edge effects and priority effects could all improve our capacity to predict how landscape heterogeneity affects biodiversity loss. Restoration ecologists should collaborate with landholders and farmers to identify the strategies that co-benefit species richness and farm productivity, not only within individual site, but at the landscape scale, across multiple cropping systems and climates. Increasingly, ecological research is focusing on ways to use farm waste to enable restoration of the wider landscapes in which they are embedded. Farm by-products can be repurposed as soil amendments: compost, manure, green waste (e.g. coffee pulp, fruit peels) and biochar have all been used to improve soil quality in degraded habitat, and these inputs generally enhance vegetation recovery.16 A meta-analysis of biochar impacts on tree growth found a 41% increase in the growth of seedlings and saplings,17 whilst an experiment involving addition of farm waste to a degraded tropical pasture found a three-fold increase in the species richness of regenerating woodland nearly two decades later.18 This research is in its early stages, however, and there are likely many unleveraged opportunities to link a growing portfolio of sustainable agricultural practices with restoration efforts off-farm. Sustainable practices adopted by individual farmers not only benefit current agricultural ecosystems, but can also 'future-proof' restoration efforts, buffering landscapes against worsening climate extremes. Agroforestry is frequently adopted by farmers specifically to protect crops against extremes of heat, drought, rainfall, and wind; non-timber forest products are also important sources of revenue when crop yields are poor.19 Techniques such as taungya (growing crops in early-stage plantations), alley cropping, and integration of trees with pisciculture all provide family farms with diverse sources of income in fluctuating environments.20 In turn, widespread adoption of practices that increase tree density in agricultural landscapes can have major benefits for biodiversity and for climate mitigation.21 Much more research is needed, however, to assess the various co-benefits of different forms of agroforestry. Furthermore, implementing agroforestry to mitigate climatic uncertainty in the long-term can often have short-term costs for the farmer, including a temporary reduction in yields.22 Therefore, adoption of pro-environmental practices (such as planting shade trees, or allowing forest restoration on-farm) often requires financial incentives, and is more likely on larger farms which benefit from economies of scale.23,24 There is a need for new financial instruments that can channel funding directly to the small farmers whose desire to adopt regenerative agricultural techniques is most strongly limited by access to capital. Ultimately, the ingenuity and innovation of smallholder farmers provides tremendous hope at a time when governments and large corporations are failing to meet their stated commitments to the climate and biodiversity. In a survey of agroecological farmers in Europe, most participants expressed that their farming practices were motivated, in part, by a desire to help restore the natural world.25 This suggests the potential for a large-scale, bottom-up change in the way agriculture is practiced. Restoration ecologists need to harness this drive to achieve the best outcomes for nature. The principles of regenerative agriculture can inspire us to restore not only plant communities, but the soils upon which they depend (soils are too often neglected in restoration ecology!)26 More fundamentally, changes in land use and land management across farms, pastures, and restored natural habitats will challenge ecologists to work across scales and across disciplines, thereby finding scalable and accessible solutions to our most pressing environmental problems.