Viewpoint Pitfalls of Tree Planting Show Why We Need

People-Centered Natural Climate Solutions Downloaded from https://academic.oup.com/bioscience/advance-article/doi/10.1093/biosci/biaa094/5903754 by Sveriges Lantbruksuniversitet user on 16 September 2020

FORREST FLEISCHMAN, SHISHIR BASANT, ASHWINI CHHATRE, ERIC A. COLEMAN, HARRY W. FISCHER, DIVYA GUPTA, BURAK GÜNERALP, PRAKASH KASHWAN, DIL KHATRI, ROBERT MUSCARELLA, JENNIFER S. POWERS, VIJAY RAMPRASAD, PUSHPENDRA RANA, CLAUDIA RODRIGUEZ SOLORZANO, AND JOSEPH W. VELDMAN

cientists, corporations, mystics, ecologically effective and socially just on forests and trees, scientists and Sand movie stars have convinced strategies to improve climate mitiga- policymakers miss the opportunity policymakers around the world that tion efforts. to conserve and restore the wide a massive campaign to plant trees diversity of Earth’s ecosystems that should be an essential element of Ecosystems, not tree planting contribute to climate change mitiga- global climate policy. Public dialogue campaigns, capture and store tion and adaptation. has emphasized potential benefits carbon of tree planting while downplaying In terrestrial ecosystems, plants cap- Preventing ecosystem destruction pitfalls and limitations that are well ture carbon from the atmosphere, is the most cost-effective natural established by social and ecological which is stored in biomass and soils. climate solution research. We argue that if natural cli- Through processes including micro- Because ecosystems are crucial mate solutions are to succeed while bial decomposition, herbivory, and to carbon sequestration, avoiding economies decarbonize (Griscom fire, carbon is released back to the deforestation, improving forest man- et al. 2017), policymakers must recog- atmosphere. Because most ecosys- agement, and protecting grasslands, nize and avoid the expense, risk, and tems have the potential to capture peatlands, and shrublands from land- damage that poorly designed and hast- more carbon than they lose, a host use conversion should be the priority ily implemented tree plantings impose of natural climate solutions have (Temperton et al. 2019). Tree planting on ecosystems and people. been proposed to enhance carbon campaigns divert funding from con- We propose that people-centered sequestration (Griscom et al. 2017). servation toward riskier, more costly, climate policies should be developed Despite the importance of below- and less effective interventions. that support the social, economic, and ground biomass and soil organic Planting trees without addressing the political conditions that are compat- matter to carbon storage, the most social drivers that caused deforesta- ible with the conservation of Earth’s visible and easily measured carbon tion in the first place will not mitigate diversity of terrestrial ecosystems. resides aboveground­ in trees. The climate change because those same Such a shift in focus, away from tree high visibility and cultural resonance drivers will destroy planted forests planting and toward people and eco- of trees has led advocates to elevate or shift ecosystem destruction else- systems, must be rooted in the under- tree planting as paramount among where. Globally, the most prominent standing that natural climate solutions natural climate solutions (Veldman ­land-based source of carbon emis- can only be effective if they respond to et al. 2019). Unfortunately, large- sions is the expansion of commodity the needs of the rural and indigenous scale tree planting programs have agriculture (IPBES 2018). To protect people who manage ecosystems for high failure rates, resulting in wasted ecosystems from commodity agri- their livelihoods. resources and little carbon sequestra- culture, it is essential to secure the To motivate this shift in focus, we tion (Duguma et al. 2020). Worse rights of rural and indigenous people highlight ten pitfalls and mispercep- yet, planting in ecosystems with to make land management decisions. tions that arise when large-scale tree naturally sparse tree cover, such as Land rights must be coupled with planting campaigns fail to acknowl- savannas and peatlands, is destruc- economic policies that support eco- edge the social and ecological com- tive for biodiversity and counterpro- system-friendly land-use practices, plexities of the landscapes they aim ductive for addressing climate change provide just compensation for the to transform. We then describe more (Temperton et al. 2019). By focusing carbon that ecosystems store, and

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historically occur destroys the habitats of plants and animals adapted to open ecosystems and threatens the liveli- hoods of people dependent on those Downloaded from https://academic.oup.com/bioscience/advance-article/doi/10.1093/biosci/biaa094/5903754 by Sveriges Lantbruksuniversitet user on 16 September 2020 ecosystems to produce wild game and domestic livestock. The iconic savan- nas of Africa are a prime example of the ecosystems that are threatened by large-scale afforestation campaigns (Bond et al. 2019). In addition to the biodiversity cost, because fire and tree- killing megafauna, such as elephants, are natural forces in these ecosystems, afforestation provides less long-term carbon storage than maintaining savannas in their open state, where most carbon is protected from fire and herbivory underground.

Trees can reduce water Figure 1. Government officials inspect a 2-year-old plantation of Eucalyptus availability clones on government-controlled land in Telangana, India. Low biodiversity, Advocates of tree planting often soil disturbance, exacerbated fire risk, altered hydrology, and restricted access assume that trees improve ground and to local people mean that this afforested land, although a potentially valuable surface water recharge, but the real- source of wood fiber for paper, disrupts rural livelihoods and should not be ity is more complicated: In the wrong considered a natural climate solution. places, planted forests deplete ground water and can cause streams to dry up (Jackson et al. 2005). Although trees offer incentives for governments, cor- Tree plantations sequester can facilitate water infiltration into porations, and land managers to con- less carbon, less securely, than soils, they also increase evaporation serve ecosystems (IPBES 2018). naturally regenerated forests of intercepted rainfall and transpira- Global forest restoration initiatives tion from leaf surfaces. The impact of Forests can regrow on deforested promote fast-growing plantations of trees on the balance between recharge land without tree planting commercial pulp and timber species and evapotranspiration is compli- In most places where reforestation as a natural climate solution despite cated and depends on many factors is desirable, forests can regenerate clear evidence that these plantations (Jackson et al. 2005). If a cobenefit of naturally from seeds or resprouts, lead to little long-term carbon storage a proposed tree-planting scheme is even in landscapes that appear to (figure 1; Lewis et al. 2019). Worse yet, to enhance water resources, a careful be highly degraded. Because natural widely planted species in the genera site-specific evaluation is imperative regeneration requires little human Pinus and Eucalyptus are extremely to determine whether potential gains intervention, it is usually much flammable and can exacerbate wild- in recharge will be offset by increased less expensive than tree planting. fire risk and ecosystem carbon loss evapotranspiration. Whereas natural regeneration often (Veldman et al. 2019). To be clear, fast leads to faster forest recovery, greater growing trees can serve an economic Trees can warm the atmosphere carbon storage, and more cobenefits purpose, but should not be confused Trees interact with the climate system for biodiversity and people, misap- for forest restoration or a natural cli- in ways that can cause warming to plied tree planting can hinder for- mate solution. exceed the cooling benefit of carbon est regrowth (Duguma et al. 2020). sequestration (Li et al. 2015). Trees, Where natural regeneration is insuf- Tree plantations in grasslands, particularly evergreen conifers, are ficient, assisted natural regeneration shrublands, and peatlands destroy darker and taller than most other land may involve planting a small number biodiversity covers, and therefore absorb more visi- of trees targeted to specific goals— Many ecosystems that do not naturally ble and ultraviolet sunlight (shortwave such as establishing seed sources support dense tree cover are targeted radiation) compared to highly reflec- or species that are valued by local for large-scale tree planting (figure 2; tive bare ground, snow, or grasses. people—rather than maximizing the Veldman et al. 2019). Establishing tree When trees replace highly reflective number of trees planted. plantations where forests did not surfaces, the albedo of the ecosystem

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select the trees they need, maintain their local food production systems, and secure the future benefits of eco- system conservation (Duguma et al. Downloaded from https://academic.oup.com/bioscience/advance-article/doi/10.1093/biosci/biaa094/5903754 by Sveriges Lantbruksuniversitet user on 16 September 2020 2020, Malkamäki et al. 2018).

Tree planting targets the global south to capture emissions from the global north Although the majority of carbon emissions come from the industrial- ized countries of the global north, large-scale planting schemes focus on the opportunity to plant trees in the global south (Bond et al. 2019, Lewis et al. 2019). Proponents of large-scale tree planting, such as Plant-For-the- Planet and the Trillion Tree Campaign, equate tree planting with climate justice and prosperity for the global Figure 2. As part of an effort to “improve” forest cover in Telangana, India, south. Unfortunately, these propo- foresters bulldoze savanna–woodlands to establish a plantation of Eucalpytus nents ignore the opportunity costs of clones. Similar plantation activities around the world frequently replace intact using land for trees instead of other ecosystems with commercial tree species that offer few carbon, biodiversity, or economically beneficial activities. livelihood benefits. Furthermore, they feed the public per- ception that tree planting at its best is good and at its worst is benign. To the decreases and more shortwave radia- mortality rates. In the rush to achieve contrary, because tree planting poses tion is absorbed, which is emitted as targets, forest restoration fails because significant risks to ecosystems and heat (longwave radiation). The warm- trees are planted incorrectly, in the people, critical questions of social jus- ing effect of trees is particularly pro- wrong places, and without the support tice must be answered by proponents nounced in cold, snowy regions, such of local people. Successful reforesta- of tree planting for climate change as alpine and boreal forests, as well as tion programs must plan for long-term mitigation. Is it just for the states of arid and seasonally dry regions, where maintenance by people who live and the global north to ask the world’s cloud cover is sparse. In general, natu- work nearby. Glamorizing and reward- poorest people and most threatened ral forest restoration in high rainfall ing the act of tree planting undermines ecosystems to bear the costs of fossil regions, such as the humid tropics, local institutions and social networks fuel emissions? cools the climate, but there are many that are required for long-term carbon locations on Earth where tree planting sequestration. Effective climate solutions require cannot be considered a natural climate social systems that support solution because of unintended warm- Tree planting threatens rural people to conserve ecosystems ing (Griscom et al. 2017). livelihoods Climate change is a complex problem Tree planting programs often target for which tree planting is a simplistic Perverse financial incentives lead ecosystems or farmland that rural solution that often results in a mis- to rushed planting and high tree people depend on for subsistence match between the technical capacity mortality livelihoods (Malkamäki et al. 2018). of foresters and the ecosystems and When ambitious targets for the num- Frequently these people have inse- social contexts they target. For natural ber of hectares or number of sap- cure land tenure, and the land may climate solutions to be effective, they lings planted are rewarded with large be viewed by governments or other must focus on the people whose deci- monetary commitments, governments actors as “available” for tree planting. sions determine the long-term viability and other organizations tend to focus Replacing croplands with trees can of ecosystem conservation and carbon on the act of planting rather than result in unemployment for agricul- storage. Because long-term invest- long-term maintenance to ensure tree tural workers and elevate food prices ments require local support, natural survival and growth (Duguma et al. (Lewis et al. 2019). Tree planting can climate solutions are more likely to be 2020). As a result, many tree plant- bring positive livelihood benefits, but successful if they provide benefits for ing initiatives have very high tree only if land rights enable people to rural and indigenous people who rely

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on ecosystems for their livelihoods. Acknowledgments landscape restoration. Restoration Ecology For small-scale farmers, pastoralists, We thank Karen D. Holl for help- 27: 705–719. Veldman JW, et al. 2019. Comment on “The and forest-dwelling people to pros- ful feedback on a previous version of

global tree restoration potential.” Science Downloaded from https://academic.oup.com/bioscience/advance-article/doi/10.1093/biosci/biaa094/5903754 by Sveriges Lantbruksuniversitet user on 16 September 2020 per while conserving and restoring this manuscript. FF, AC, EAC, HWF, 366: eaay7976. ecosystems, they must be empowered BG, VR, PR, and CRS were supported with decision-making rights over land by NASA award no. NNX17AK14G. Forrest Fleischman ([email protected]) is an and must benefit economically from JWV was supported by USDA-NIFA assistant professor in the Department of Forest sustainable land management (IPBES Sustainable Agricultural Systems Resources at the University of Minnesota, in St. Grant no. 2019-68012-29819, USDA- Paul, Minnesota, United States. Shishir Basant 2018). is a doctoral candidate in the Department of For example, expansion of com- NIFA McIntire-Stennis Project no. Ecology and Conservation Biology at Texas modity agriculture, which is often 1016880, and the National Science A&M University, in College Station, Texas, driven by distant investors, can be Foundation under award no. United States. Ashwini Chhatre is an associate checked by securing land rights and DEB-1931232. professor of public policy and executive director of the Bharti Institute of Public Policy, at the enhancing the political power of Indian School of Business, in Hyderabad, India. indigenous and rural people. This References cited Eric A. Coleman is an associate professor of involves redirecting investment and Bond WJ, Stevens N, Midgley GF, Lehmann political science at Florida State University, in using modern technology to moni- CER. 2019. The trouble with trees: Tallahassee, Florida, United States. Harry W. tor and enforce both certifications Afforestation plans for Africa. 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Local cooling and warming effects Forest Department, in Shimla, India. Claudia modity agriculture. Once developed, of forests based on satellite observations. Rodriguez Solorzano is an adjunct assistant people-centered climate solutions Nature Communications 6: 6603. professor in the Department of Forest Resources will be the most effective natural Malkamäki A, D’Amato D, Hogarth NJ, at the University of Minnesota, in St. Paul, climate solutions because they will Kanninen M, Pirard R, Toppinen A, Zhou Minnesota, United States. Joseph W. Veldman W. 2018. A systematic review of the socio- is an assistant professor in the Department of align conservation goals and the economic impacts of large-scale tree plan- Ecology and Conservation Biology at Texas A&M interests of the rural people respon- tations, worldwide. Global Environmental University, in College Station, Texas, United sible for managing ecosystems. Change 53: 90–103. 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