 Today I'll be talking about ways to improve outcomes of initiatives to restore tree cover. As I'm sure you all know, there are many forest restoration and tree planting campaigns. One of the first was the Bond Challenge, which was underpinned by regional initiatives, such as the 20 by 20 initiative in Latin America. More recently, there are at least three efforts globally to try to plant a trillion trees. And then there's also the UN decade ecosystem on restoration, which is just starting. And there are many more initiatives. Tree planting can have a lot of potential beneficial outcomes, such as enhancing carbon water storage, increasing biodiversity, and enhancing livelihoods of stakeholders if they are engaged throughout the process. But it can also have a number of unintended negative effects, just a few of which are reducing water yield if trees are planted extensively in errant systems, destroying native ecosystems if trees are planted into historic grasslands, and also potentially social conflicts if their projects are top-down and potentially displacing current land uses, agricultural uses into existing forests, which actually results in more forest loss. In order to increase the potential beneficial outcomes and minimize unintended negative consequences, we need to do a better job of planting, of tree planting efforts. The first thing to recognize is that tree planting is an action, not an endpoint. So people plant trees for many different reasons, and it's important from the outset to talk about what those are for a given project. People plant trees to conserve biodiversity, to sequester carbon, to improve air quality, also to practice agroforestry or earn money from timber, and many, many more reasons. And some of these reasons, some of these goals can be achieved simultaneously, but we also have to recognize that there are trade-offs. So the species that we might plant for agroforestry might be different than for maximizing carbon or for biodiversity. And so in order to be able to have a successful effort and evaluate success, we need to start by talking about and agreeing upon goals amongst the different stakeholders involved. Successful tree planting requires, in addition to just goal-setting, a multifaceted decision-making process, and there are many, many questions that take time to answer and to discuss, which Pedro Broncoliano and I outlined in a recent paper in the Journal of Applied Ecology. Just a few of those questions. First, is it necessary to plant trees to achieve the project goals? In a number of cases, forests and lands that haven't been used heavily for agriculture may regenerate quickly. We know that farmer-managed regeneration can be a really cost-effective way to manage trees in some agricultural lands, or maybe direct seeding species that don't disperse naturally because of large seeds can also be a cost-effective way. And so we really need to think about, you know, do we need to plant those trees actively or can we use some sort of more of a natural regeneration or assisted regeneration strategy that's often much more cost-effective? Other questions include how much will it cost, who will pay the costs not only to plant the trees but to fence the land, to care for the trees, to monitor the trees? Is land tenure secure and how will landowners be compensated for lost income? Forests take a long time to develop and there's a pretty big track record of newly planted tree areas or newly regenerated forests being cut down soon after. And so making sure that if we're going to invest in these efforts, are the lands protected and are human livelihoods accounted for? What tree species are most likely to grow well to give insight now and in the future with climate change? Who will grow the seedlings and plant and care for and monitor the trees? And how and when will we evaluate whether the project has been successful and whether we need to take corrective actions? Many tree planting efforts just focus on how many trees go on the ground, but they don't think about whether the actual goals have been achieved over the long term. And that's critical. And as I know, there's a lot more questions that also need to be addressed. A few general principles for tree planting success is that first of all, we need to address the underlying drivers of forest degradation. We know and I know as a restrict somebody who's worked in restoration ecology for 25 years that we can never go out and recreate forests and do as good a job as what was there naturally as hard as we try. So we need to protect existing forests first and then use reforestation or tree planting as a second option. We also need to integrate decision making across scales. A lot of these reforestation initiatives are at the global scale, but they're actually implemented at the farm scale. And then there's all these other intermediate scales along the way. And often these different commitments and different groups have different goals that need to be reconciled. And the question is how do you do this integration across scales? And one of the more successful efforts that I've seen is the Atlantic Forest Pack in Brazil, which is a coalition of over 270 academic, private, business, government groups that are involved in reforestation that have worked together to develop best practices, to communicate results, to develop monitoring plans to help raise funding. And we're going to need some of those intermediate level groups to help coordinate these efforts. We need to, as I said earlier, tailor tree planting strategies to clearly state a project goals and evaluate them over a sufficiently long timeframe. We need to include stakeholders from the beginning and throughout the process if this is going to be successful. And many talks in this session will address this point. We also need to coordinate different land uses regionally so that we have areas that have forest protected, but others where the lands are used for agriculture and other uses that benefit human livelihoods. In addition to generally following these principles, in order to meet targets to increase tree cover, we'll need to take creative, scalable solutions. And we'll hear about a lot of those from our talks today. I wanted to briefly discuss three that I've been involved in that might work other places. First of all, one option is Intensive Silver Pastoral Systems where you integrate different grazing usage with more tree cover in the landscape and a mix of fodder and agroforestry plants. The idea is that if you can increase the productivity and the habitat value of the production system in the productive area, then potentially you can facilitate the release of marginal lands for forest restoration in other areas because a lot of these plenty trees help to improve productivity of the cattle production system. One of my recent graduate students, Alicia Kaye, did a work on a long-term study of how short-term payments for silver pastoral systems in Colombia and found that they helped to increase tree cover, riparian biodiversity, as well as farmer resilience to climate variability. Personally, I've been experimenting a lot with spatial tree planting approaches where you don't plant the entire area, but you strategically plant trees. The idea here is that if natural regeneration, this is over time, if you're on a site where it happens slowly, one option is to plant a plantation, but that can be really homogeneous and it takes a lot of resources. So we've been looking at the idea of planting islands of trees or nuclei, we call applied nucleation, you plant the nuclei that spread. And the idea here is that they, as I said, they facilitate recovery, but they use less resource and create more habitat heterogeneity. And what we found is that in a 16-year study that I've been doing in Zexahawi, that they can be similarly effective to plantations in facilitating forest recovery. They create heterogeneous habitat, but they may or may not be the best strategy for socially because we found that some landowners would prefer a more intensive planting system that's more orderly. And this is a key point that we're going to have to pick and choose and tailor the approaches to the local site conditions. There isn't a one-size-fits-all strategy. And a final example of another creative potentially scalable solution is work that Pedro Roncalion has been doing in Brazil, where they're interplaneting eucalyptus with native tree species. And the idea is that you harvest them after about five years, that provides income, and then it helps with forest regeneration over time. And again, there's a recent paper that summarizes the results of this work. And what he's found is that planting eucalypts increased tree biomass by about nine times, didn't inhibit regeneration of native species, and helped to offset the substantial amount of the restoration costs. And this shows a new trial that they're doing, where they have the eucalyptus planted multiple rows interplanted with native species. And once those are logged, you can see that these native species create a habitat to track birds, and then it'll help over time they anticipate that these areas will naturally regenerate inside the strips. Thanks for listening. Here are a few of the resources that I refer to, as well as information on my new book. And I look forward to hearing from a number of the other speakers about their solutions to how to scale up forest restoration.