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• Globally, our knowledge is focused on a limited set of taxonomic groups. • We know more about small and young areas, degraded by mining or agriculture. • Planted or seeded areas monitored by diversity or richness indexes are the most common investigations. • Groups evaluated and functional group approaches have been increasing in recent years. • Incomplete-Puzzle hypothesis can be a more realistic approach in restoration scenarios. Biodiversity promotion activities, such as ecological restoration, are recognized as instruments to arrest and mitigate the diminishing health of ecosystems. The restoration of fauna is a fundamental component of this process but, despite this, there are few studies that compile and discuss the knowledge produced on this topic. Hence, by seeking a general understanding of what we currently know about terrestrial invertebrates as bioindicators in restored ecosystems, the present work sought to organize knowledge in such a way as to indicate gaps and opportunities for both researchers and restorers. To this end, we searched for topics associated with restoration ecology in the Web of Science database, identifying which invertebrate groups have been studied in relation to intrinsic characteristics of ecological intervention, including type of biome, type of disturbance, restoration technique, age, project size, and indices used. We found 154 studies published between 1995 and 2018: 93.5% of which were from 2002 onwards. We detected a growing number of studies and a tendency to evaluate functional groups. Moreover, there was a high concentration of studies within a few taxonomic groups, notably Hymenoptera (Formicidae), Coleoptera, and Lepidoptera. Many of the restoration scenarios are poorly studied, for example, in temperate coniferous forests or taiga biomes, previous disturbances caused by pollution or urbanization, under certain restoration techniques such as brushwood transposition, and investigations in large or old areas. There was also a paucity of information concerning community or population-level measures of restoration success, such as the structure of communities, biomass, and dominance. We discuss some consequences of these knowledge gaps. Finally, we indicate which taxonomic groups have been evaluated in relation to each restoration characteristic considered, resulting in guidance for those wishing to engage in research and monitoring of such organisms during the restoration process. [ABSTRACT FROM AUTHOR]

Restoring fauna is a fundamental objective of ecological restoration. For organisms that depend on vegetation structures (e.g., hunting support), such as spiders, this can be difficult, especially in early stages of intervention. Multifunctionality in restoration practices occurs when one action can achieve more than one objective. Given the complexity of restoration actions and the general scarcity in resources worldwide, this property can play a key role. Therefore, we sought to study the multifunctionality of using seedling shelters to support Araneae recolonization, through the addition of structural complexity (e.g., wire mesh structures as spider webs support). We evaluated the presence of Araneae , the percentage of shelter covered by webs and elements of structural complexity (height and number of leaves,) in 32 seedlings of four tree species that had been in the restoration process for about one year. To determine the relationship between structural complexity and Araneae abundance, we used a Generalized Additive Model (GAM). We observed spiders (95.5% Araneidae) on all monitored structures (seven on average), and an average of 5% of the shelters' area covered by webs. The variation in spider abundance in shelters was correlated to seedling height and number of leaves. The taller the seedling, the fewer spiders it had, and higher spider abundance was found when seedlings had from 25 to 30 leaves. The spatial characteristics of seedlings inside screens is a condition of the quality/availability of the shelter as a resource for spider colonization. Therefore, our results indicate a possible multifunctional property of seedling shelters in improving microhabitat structure for orb-weaver spiders, as well as preventing herbivory. [ABSTRACT FROM AUTHOR]

• The Atlantic Forest is the biome with the highest number of papers on ecological restoration. • Pantanal, Pampa and Caatinga are the least studied in terms of ecological restoration. • In all biomes, most of the studies are related to monitoring. • The number of species used in restored areas is limited. • It is necessary to include different life forms, restoration techniques and studies using reference areas to measure success. The Bonn challenge aims at the restoration of 350 million hectares of degraded ladscapes by 2030. In Brazil, the restoration goal for 2030 is 12 million hectares. Despite the great demand for ecological restoration across the whole of Brazil, there have been no analyses of the studies carried out in different biomes. In addition, conservation efforts must cover all biomes, so that different regions can take advantage of the many benefits of restoration. Our aim was to identify advances and gaps in current restoration knowledge in order to guide future efforts in Brazil. Our bibliometric survey in the Web of Science using 23 keywords related to restoration generated a total of 530 papers, of which 291 were included in the analysis. The papers were published in 121 scientific journals between 1988 and 2018, with the largest number of papers in 2016. The Atlantic Forest was the biome with the highest number of studies, as it is one of the most threatened tropical forest regions in the world and maintains the largest number of research institutions and receives the highest level of funding support in the country. Regarding the types of studies, temporal monitoring was more frequent in the Amazon, Cerrado, Caatinga, and Pampa, while the monitoring at one point in time was more frequent in the Atlantic Forest. From the studies examined, 31% used a reference area for comparing restoration success. The most studied organisms were plants (81%), and among them, trees were the most frequent, followed by fungi, birds, invertebrates, mammals, and reptiles. The pre-restoration degradation differed among biomes, with deforestation for logging the most cited in the Amazon, agriculture, and livestock in the Atlantic Forest and Cerrado, logging and cattle ranching in Caatinga, and livestock in the Pampa and Pantanal. In general, active/assisted natural succession was the most frequent restoration process: planting seedlings more readily occurred in the Amazon, Atlantic Forest, and Caatinga, whereas natural regeneration in the Cerrado and Pantanal and sowing in Pampa. The studies varied among the age of restoration (>1 to 67 years for active restoration and >1 to 120 years for passive/unassisted natural succession), and the number of species planted (1 to 121 species). We identified an important regional knowledge gap for the Pantanal, Caatinga, and Pampa, as well as the need to include reference areas, evaluate different restoration techniques (besides planting seedlings), and the inclusion of other taxa and life forms in biodiversity studies apart from trees. We also identified the need to expand research to assess landscape metrics, prioritization, legislation, and public policies. [ABSTRACT FROM AUTHOR]