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Aim: Eucalypts have a widespread global distribution owing to their popularity for agroforestry and as environmental plantings. Despite an abundance of site‐specific evidence that eucalypts modify soils and soil processes, we lack a quantitative synthesis of their overall effects at the global scale. This limits our capacity to assess the likely impacts of future introductions in any given region of the world. Location: Global. Time period: 1986–2021. Major taxa studied: Eucalyptus, Angophora and Corymbia. Methods: We used a systematic search to derive a database of empirical data from 227 studies across 33 countries (neffect size = 2,806) and tested three predictions about the effects of eucalypts on soil properties and whether these effects varied with plantation age and soil depth. Results: Compared with (non‐eucalypt) native vegetation, eucalypts significantly reduced soil moisture, microbial abundance, nitrogen, cations and anions. Relative reductions in soil microbes and ions were stronger in older eucalypt plantations. A comparison of eucalypts with (non‐eucalypt) silvicultural and agropastoral systems revealed similar effects on most soil properties, although eucalypts tended to reduce potassium and enhance carbon to a greater extent than other managed systems. We found no consistent effects of eucalypts on soil pH. Main conclusions: Our study provides the first extensive global meta‐analysis of the effects of eucalypts on soil properties and processes and demonstrates that effects are highly dependent on the community with which they are compared (i.e., natural or managed). In general, our findings reinforce the widely held belief that eucalypts deplete soil nutrients and dominate water resources. Understanding how eucalypts affect soils allows us to assess their global suitability for agroforestry, soil rehabilitation and soil carbon enhancement, while considering the potential environmental costs. [ABSTRACT FROM AUTHOR]

Ecological restoration projects often have variable and unpredictable outcomes, and these can limit the overall impact on biodiversity. Previous syntheses have investigated restoration effectiveness by comparing average restored conditions to average conditions in unrestored or reference systems. Here, we provide the first quantification of the extent to which restoration affects both the mean and variability of biodiversity outcomes, through a global meta‐analysis of 83 terrestrial restoration studies. We found that, relative to unrestored (degraded) sites, restoration actions increased biodiversity by an average of 20%, while decreasing the variability of biodiversity (quantified by the coefficient of variation) by an average of 14%. As restorations aged, mean biodiversity increased and variability decreased relative to unrestored sites. However, restoration sites remained, on average, 13% below the biodiversity of reference (target) ecosystems, and were characterised by higher (20%) variability. The lower mean and higher variability in biodiversity at restored sites relative to reference sites remained consistent over time, suggesting that sources of variation (e.g. prior land use, restoration practices) have an enduring influence on restoration outcomes. Our results point to the need for new research confronting the causes of variability in restoration outcomes, and close variability and biodiversity gaps between restored and reference conditions. [ABSTRACT FROM AUTHOR]

Transplant studies have long been a cornerstone of experimental ecology. Lichens and bryophytes have several useful characteristics for transplantation: they are small, easily transported, and highly responsive to environmental gradients. Here we conduct a systematic review to synthesise lichen and bryophyte transplant studies up until March 2020 (N=454). A great majority of studies (67%) used lichen and bryophyte transplants as biosensors of airborne pollutants. Other research themes such as forest management and biotic interactions were associated with comparably modest bodies of work. A total of 247 lichen and bryophyte species had been used in transplant studies, but four species predominated: Hypogymnia physodes, Pseudevernia furfuracea, Evernia prunastri and Lobaria pulmonaria. Liverworts were only transplanted in 4% of studies, and most studies focused on epiphytic (69%) or terricolous species (31%). A small group of studies (N=15) used whole-community transplants with areas ranging from 25–250,000 cm2. Apart from pollution research, studies centered on assisted colonization and simulated climate change appear to be increasing most rapidly in time. There were several recurrent lines of investigation within the included literature (e.g., edge effects, colonization of young forests, climate change effects and local adaptation) and we synthesise the key results. We recommend that future research address underrepresented taxa (e.g., liverworts, biological soil crusts) and geographic gaps, namely Australia and Africa. [ABSTRACT FROM AUTHOR]

Aim: Organisms that disturb the soil while foraging or creating shelter (ecosystem engineers) can have profound effects on ecosystems. Soil ejecta from these disturbances can enhance surface nutrients and the resulting depressions accrue organic matter and develop into biological hotspots. Here, we describe a global meta‐analysis of studies that assessed the impacts of vertebrate soil disturbance on both biotic and abiotic components of ecosystems. Location: Global land surface. Time period: 1941–2016. Major taxa studied: Vertebrates. Methods: After conducting a systematic literature search, we quantitatively synthesized the findings of 149 published studies that compared disturbed and undisturbed surfaces. Our meta‐analysis included 64 engineer species, primarily comprised of rodents and a subset of other mammals. Results: We found that vertebrate soil disturbance significantly enhanced soil nitrogen (by 77%) and phosphorus (35%), and the productivity (32%) and recruitment (32%) of vascular plants. Disturbances had a greater cover of bare soil (126%) than undisturbed controls, and higher abundances of secondary vertebrates (1,233%), that use pre‐constructed burrows as shelter and foraging grounds. Soil disturbance significantly reduced water run‐off (63%) and the abundance of biocrusts (82%). Soil disturbance effects generally intensified with increasing aridity, and the magnitude of soil disturbance effects was not moderated by the area of the disturbance. Disturbances older than 12 months were more distinct from the surrounding matrix than fresh disturbances. The phylogeny of engineers was unrelated to their ecosystem effects, indicating that the same functionality could readily evolve in different taxa. Main conclusions: In general, disturbances become localized patches of elevated functioning, providing strong evidence that vertebrate engineers, especially those in drylands, are an important source of environmental heterogeneity. [ABSTRACT FROM AUTHOR]