Young voices and visions for tropical restoration science in the UN Decade on Ecosystem Restoration

Protecting ecosystems, in their current extent and function, is no longer sufficient to meet global conservation and sustainable development goals: we must also restore ecosystems to remedy past degradation (Gann et al., 2019; Leclère et al., 2020). Although ecosystem restoration is needed globally, focusing efforts on the tropics may provide the largest benefits to humans and nature (Strassburg et al., 2020). The tropics harbor a disproportionate amount of global “biodiversity hotspots” and therefore restoring habitat cover, connectivity, and quality in degraded tropical landscapes is critical to preventing species extinctions (Dutta et al., 2018; Newmark et al., 2017). Also, tropical restoration strategies that improve vegetation structure, functionality, and diversity can increase carbon sequestration and therefore contribute substantially to climate change mitigation strategies (Griscom et al., 2020). Additionally, ecosystem restoration in tropical landscapes can enhance water security (Ellison et al., 2017), improve water quality (Pires et al., 2017), facilitate climate change adaptation (Senior et al., 2019), and can contribute to income, consumption, and other dimensions of livelihoods and wellbeing (Bradbury et al., 2021). Young people are frequently overlooked, undervalued, or left out from key stages of sustainable development, leading to disengagement, and possible failure of projects (Barraclough et al., 2021). This trend might become relevant, if not already, in research communities involving young voices in academia focusing on tropical restoration science. Young voices are needed when developing and implementing restoration initiatives because they embody and reflect a different social, cultural, political, and academic environment than those of academics at advanced stages of their careers. For instance, young academics are likely to spend substantially longer time in the field during their graduate research, allowing them increased ability to witness how restoration affects local ecosystems and people. This is relative to more senior academics who would have cumulatively spent longer time doing fieldwork but might not as they progress to senior academic positions. Today, young restoration researchers develop their perspectives considering contemporary worldviews in conservation, such as Recoverable Earth narratives versus Finite Earth narratives, that is, grounded adaptive action to restore nature for the better future of nature and people versus morally motivated conservation foregrounded in villainous and heroic roles and worrying change, and pragmatic ways of approaching conservation and

restoration in contrast with absolutist values (Jepson, 2019). This is a remarkable shift in ideals, when compared to relatively senior academics (senior in terms of age and time since graduating from a graduate program). The inclusion of young voices and visions in restoration science is, therefore, critical for a forward-looking and innovative development of this field.
Hence, successful restoration initiatives are increasingly recognizing the involvement of the younger generation, including those who are young in their academic careers (IUCN, 2017a(IUCN, , 2017b. For instance, involving young voices in restoration are a key component of the current UN Decade on Ecosystem Restoration (UNEP, 2021). However, the priorities, steps, and action points that young researchers envision for the UN Decade are largely unknown. This crucial information will guide restoration-focused science, policy, finance, and on-the-ground implementation of activities, fostering future leaders in the field of ecosystem restoration. Here, we aim to outline key visions that young researchers have for the future of tropical restoration science, supported by our own experiences as young restoration scientists and the findings from a survey that we

| YOUNG VOI CE S IN AND VIS I ON S FOR TROPI C AL RE S TOR ATI ON SCIEN CE SYMP OS IA
We define young voices in academia as voices of current graduate students (Master's level or doctoral students) or postdoctoral scientists within 1-2 years of completion of their doctorate degrees.
We organized an open format session at the online ATBC 2021, titled "Young Voices in and Visions for Tropical Restoration Science" (ATBC, 2021). The aims of this session were as follows: (1) to provide a platform for doctoral students to showcase their research and visions for restoration science in tropical landscapes, (2) to build a community of young restoration scientists working toward a sustainable future, and (3) to present and share a vision for the future of tropical restoration science by including the wider community of young researchers. The session consisted of a panel of six doctoral candidates who presented case studies of restoration-focused research in the tropics. These case studies encompassed tropical mountain, agricultural, and forest landscapes and featured a range of methodologies that are advancing the field of restoration science, including the use of remote sensing and derived products, functional ecology, field-based data collection, and governance instruments. Lastly, each panelist presented their vision for the future of tropical restoration (Table 1). We deployed a 9-multiple choice question survey during the Q&A part of the session, asking respondents for important actionable steps in the UN Decade on Ecosystem Restoration, their vision for the future of tropical restoration science, and demographic information. We also provided the option to specify additional categories or ideas. We designed the survey based on our joint expertise and experience doing tropical restoration science research and using recent relevant literature (Aronson et al., 2020;Di Sacco et al., 2021;Gann et al., 2019;Osborne et al., 2021).
We received 11 responses, nine of which were students (up to PhD) aged 18-35 years. Of the actionable steps, "More effective academic-practitioner collaborations" was most ranked among the top three priorities (91% of respondents) followed by "Addressing social dimensions of effective restoration such as governance, land tenure issues" (72.7% of respondents) and "Addressing critical research gaps in the natural science side of restoration ecology" (54.5% of respondents) ( Figure 1). Additionally, respondents said that actionable steps should "engage and collaborate with major corporate actors, especially transnational corporations whose activities have direct impacts on land use and land cover change" and highlighted the need for "more investments in restoration science, particularly for projects/individuals to continue to do long term research…", and the need for "...capacity building as an opportunity to co-develop actionable restoration knowledge…".

| YOUNG VIS IONS FOR TROPIC AL RE S TOR ATI ON SCIEN CE FOR THE UN DEC ADE ON ECOSYS TEM RE S TOR ATI ON
We used the survey responses from the session participants (panelists and survey respondents) to inform our five visions for how young restoration scientists can actively contribute to developing restoration science over the UN Decade. Here, we outline these key visions and provide achievable contributions that young restoration scientists can make ( Figure 2). • The aim of this study is to understand the challenges that emerge in the governance process on implementation of restoration efforts • Using semi-structured surveys and the lens of cross-scale and cross-level interaction between governance actors and natural regeneration efforts, the study estimates unrecognized actors and persistent mismatches across governance and ecological scales • Short-term government efforts did not match long-term restoration processes. Political cycles pushed for immediate success in the form of tree planting campaigns, with little focus on natural regeneration. There is a mismatch in federal budgets allocation for sustaining alternative livelihoods from restoration processes (Ecuador study- (Wiegant et al., 2020)) • Restoration science studies in the future should focus on understanding actual dynamics of implementing landscape restoration targets at subnational levels • Restoration science in the future should focus on current challenges in multilevel restoration governance, which will then offer opportunities to inform and improve ongoing and future restoration processes Evidence-based partnerships, at every step, will inspire impactful research allowing achievement of the goals of ecosystem restoration (Brancalion & Chazdon, 2017;Holl & Brancalion, 2020). 2. Vision 2-Tropical restoration science that is conducted through a transdisciplinary lens.
Ecosystem restoration is an inherently complex endeavor and needs to be viewed through and practiced using cross-disciplinarity (i.e., view from different perspectives) and interdisciplinarity (i.e., requiring integration of knowledge and methods from different disciplines) (Keynejad et al., 2021). However, ecosystem restoration can be most effective when a transdisciplinary approach is taken, allowing for the limitations of traditional disciplines of ecology and environmental sciences to be overcome. Currently, restoration studies across the tropics are biased toward certain biomes and regions, and few occur across large spatial or temporal scales (Christmann & Menor, 2021). Findings from such studies are therefore site-specific and context-dependent, limiting the extent to which their findings apply to restoration initiatives more widely. Tropical restoration science in this decade should represent science across multiple ecosystems and geographies, including a variety of data gathering techniques (Dudley et al., 2020;Temperton et al., 2019). Ecosystem restoration science should tackle disentangling and reconciling the contrasting outcomes of different ecosystem benefits and societal goals of livelihoods and well-being (Holl & Brancalion, 2020;Martin et al., 2021). In this vein, restoration projects must be monitored and evaluated after implementation and on long time scales (Poorter et al., 2021). Such long-term monitoring efforts are needed to assess achievement of multiple end goals decided at the inception of the project using participatory approaches that include the most vulnerable communities. We recommend using both established field-based monitoring methods and innovative and com- Big data restoration studies, including large-scale and long-term data, have provided the impetus for restoration action by showing the potential of restoration activities to achieve multiple goals at global and continental scales (Bastin et al., 2019;Brancalion et al., 2019;Griscom et al., 2017;Strassburg et al., 2020). However, these studies have many assumptions that vary by region and lack nuanced contextual information, potentially leading to ineffective or even harmful restoration outcomes (Holl & Brancalion, 2020). In the coming decade, fine-scale analyses should also be completed to support bottom-up policy design and delivery that will better support national and subnational policy making (Murcia et al., 2016).
Contribution 5-Global studies are often the basis for international campaigns, policies, and agreements, and also influence the development of restoration policy at the national and subnational F I G U R E 2 Five visions and respective action steps from and for the young restoration science community. The visions are in no order of importance levels. Young restoration scientists can design studies that analyze the trade-offs between restoration goals, that can critique and refine global scientific assumptions, and that estimate uncertainty when accounting for contextual information, available at regional and subnational scales. In this manner, young restoration scientists can support effective policy design and delivery at the scales of implementation.

| CON CLUS ION
There is a magnifying glass on the state of restoration (science, implementation, evaluation) in the current UN Decade on Ecosystem Restoration, with attention on successes, failures, and lessons to be shared. The current and future generations of restoration scientists will have to step up and lead the way, a challenge that will be as exciting as it is complex. Hence, supporting and increasing the participation of young voices in restoration science is vital to ensuring current and future successes within the field of restoration. Young restoration scientists can positively impact policy at multiple spatial scales by building transdisciplinary collaborations with local stakeholders, across ecosystems, regions, and goals/outcomes with implicit long-term monitoring and evaluation schemes. Proactive inclusion of these voices and, indeed, all restoration-focused voices, in the future restoration initiatives is critical to the development of this field as a science, and to ensuring that the impact of the UN Decade is beneficial and long-lasting.

ACK N OWLED G M ENTS
We thank the organizing committee of the annual meeting of the Association of Tropical Biology and conservation 2021 for selecting our session proposal. We especially thank Ivan Ortiz Rodriguez, webmaster of the annual meeting, for patiently answering all our queries about the session and for providing us the post-conference statistics. We thank all the panelists who presented at the session, all audience who attended the session, and all audience who completed the survey. We thank Dr. Imma Oliveras, Dr. Yit Arn Teh, and Dr.

CO N FLI C T O F I NTE R E S T
The authors declare no conflicting interests.

AUTH O R CO NTR I B UTI O N S
TG and TC conceived the idea for the session, wrote and submitted the proposal and organized and ran the session during the annual meeting of the Association for Tropical Biology and Conservation 2021 (with assistance from the Association for Tropical Biology and Conservation). TG, TC, MP, RP, and other panelists designed the survey. TG wrote various manuscript drafts with feedback and additional input from TC, MP, and RP. TC designed Figure 2 with additional input from TG.

DATA AVA I L A B I L I T Y S TAT E M E N T
The data that support the commentary are available from the Association of Tropical Biology and Conservation, as part of the annual meeting of the Association of Tropical Biology and Conservation 2021. Restrictions apply to the availability of these data, which were used with permission.

ACK N OWLED G M ENT
Open access funding enabled and organized by Projekt DEAL.