Many degraded ecosystems need active restoration to conserve biodiversity and re‐establish ecosystem function, both highlighted targets of the UN Decade on Ecosystem Restoration and the proposed EU Nature restoration law. Soil translocation, where both plant propagules and their associated soil biota are co‐introduced, has increasingly been proposed as a powerful restoration technique for terrestrial ecosystems. However, a synthesis of the effectiveness of this method across ecosystems is lacking. To address how soil translocation affects restoration success, we performed a meta‐analysis synthesizing data from 46 field experiments and their respective reference ecosystems in 17 countries across four continents. In each experiment, vegetation composition was recorded in response to soil translocation treatments and the resultant vegetational changes (diversity and composition) were quantified. We found that soil translocation leads to plant community development further away from the control and more towards the reference plant communities compared with treatments where only plant propagules were introduced. However, the variability of effect sizes among experiments was large, suggesting strong dependence of restoration success on restoration context. We found that restoration success was more likely on loamy soils and when translocation treatments were implemented over larger spatial areas (>180 m²). Furthermore, we found that restoration success either consistently increased or decreased over time depending on the experiment. Not only is this congruent with positive feedbacks between plant and soil communities driving plant community development, but it also suggests that the composition of the translocated plant and soil communities, and initial starting conditions, are critical for long‐term restoration success. Synthesis and applications. Our analysis highlights soil translocation can be a successful restoration method across a broad range of ecosystems. However, its implementation needs to depend on a thorough evaluation of local conditions and the potential added value. Further refinement of soil translocation techniques is needed to increase success rates.

Tropical forest canopies are the biosphere’s most concentrated atmospheric interface for carbon, water and energy^1,2. However, in most Earth System Models, the diverse and heterogeneous tropical forest biome is represented as a largely uniform ecosystem with either a singular or a small number of fixed canopy ecophysiological properties³. This situation arises, in part, from a lack of understanding about how and why the functional properties of tropical forest canopies vary geographically⁴. Here, by combining field-collected data from more than 1,800 vegetation plots and tree traits with satellite remote-sensing, terrain, climate and soil data, we predict variation across 13 morphological, structural and chemical functional traits of trees, and use this to compute and map the functional diversity of tropical forests. Our findings reveal that the tropical Americas, Africa and Asia tend to occupy different portions of the total functional trait space available across tropical forests. Tropical American forests are predicted to have 40% greater functional richness than tropical African and Asian forests. Meanwhile, African forests have the highest functional divergence—32% and 7% higher than that of tropical American and Asian forests, respectively. An uncertainty analysis highlights priority regions for further data collection, which would refine and improve these maps. Our predictions represent a ground-based and remotely enabled global analysis of how and why the functional traits of tropical forest canopies vary across space.

Direct seeding is a promising technique for ecological restoration, but it has been poorly studied in neotropical savannas. Different types of plant cover (no cover, crops, or green manure) and fertilization (unfertilized, synthetic fertilizer, or poultry litter) were used to verify if survival and growth of different tree species after direct seeding could be enhanced by the use of any combination of these techniques. Seedling emergence, establishment, and growth were followed for 2 years for six savanna tree species sown in an agricultural field in Central Brazil. Germination was high (52%, on average) for Anacardium occidentale, Aspidosperma macrocarpon, Hymenaea stigonocarpa, Dipteryx alata, Eugenia dysenterica, and Magonia pubescens. Six additional species were planted, but less than 5% of these seeds germinated. Crops (60% shade) did not affect seedling survival and biomass compared with the control treatment, supporting the use of this strategy during the initial phase of restoration to involve farmers in the process. In contrast, the excessive shading (95%) from the green manure treatment decreased the survival of two species and the growth in biomass and diameter of five species, especially when combined with fertilization. Seedling growth was very slow throughout the experiment, requiring extended weed management. This study supports the use of direct seeding of the studied species for savanna restoration, but methods could be improved to include a larger number of species.

Aims: To address whether seed and seedling functional traits have a significant effect on germination rates and seedling survival in direct‐seeding restoration efforts. We tested the hypotheses that: (1) seed burial only favours the emergence of round seeds; and (2) straw mulching improves soil moisture and prevents the emergence of the invasive grass Urochloa decumbens, promoting the establishment of native tree seedlings.Location: Experimental field, Central Brazil. Savanna, recently dominated by exotic pasture.Methods: We evaluated the effects of seed burial (surface and buried) and mulching (no‐mulch, 5‐cm straw mulch and 10‐cm straw mulch) on the emergence, survival and growth of 16 species of native Cerrado tree species with variable seed sizes and shapes and seedling types. Thirty seeds of each species were sown per treatment combination in three blocks.Results: Seed burial did not affect the emergence of species with round seeds, but negatively affected species with flat seeds and phanerocotylar–epigeal–foliaceous seedlings. Straw mulching reduced the emergence of flat seeds and phanerocotylar seedlings, but increased soil moisture and strongly reduced U. decumbens emergence, resulting in a higher growth rate of tree seedlings up to 1 yr for five species.Conclusion: Direct seeding is an effective technique to plant a mixture of Cerrado tree species for restoration, provided the soil is well prepared and there are mechanisms to control invasive species.