Trophic rewilding is gaining rapid momentum as a means of restoration across the world. Advances in research are elucidating the wide‐ranging effects of trophic rewilding and megafauna re‐establishment on ecosystem properties and processes including resilience, nutrient cycling, carbon sequestration, productivity and plant richness. A substantial gap remains in trophic rewilding research on how rewilding affects the frequency and expression of plant functional traits, a key hypothesised avenue by which megafauna can affect biodiversity and ecosystem processes. Yet, there is extensive literature examining the effects of mammal herbivory and exclusion on plant traits from which we may infer potential effects of megafauna reintroductions. Here, we synthesise the literature to show the multifaceted ways that plant functional composition responds to mammalian herbivory and explore how these responses are modulated by the density and identity of herbivores as well as resource availability, ecosystem productivity and historical contingency. We further explore these interactions in a quantitative analysis on European plant species. In addition, we link these broad patterns between mammal herbivory and traits to literature on plant invasions to predict how trophic rewilding may be able to reduce invasive plant dominance, as ecosystems around the world are transitioning towards novel states, occupied by a mix of native and introduced species. Expanding current research on herbivore effects (and their implications for trophic rewilding) beyond plant species richness and towards measurable functional traits can help assess and quantify processes that were not previously possible. Trait approaches can help to test mechanistic hypotheses on the top‐down impacts of large herbivores on plant communities to reveal links between trophic rewilding and ecosystem processes and properties. Synthesis. Given the rapid, much‐needed expansion of restoration and rewilding activities across the world, trait‐based ecology offers a pathway to generalisable predictions of the ecosystem impacts of rewilding, particularly in the context of both the unique landscape processes associated with rewilding (e.g. landscape scale spatiotemporal variability, dispersal) and of widely emerging novel ecosystems.

Latitudinal diversity gradients are among the most striking patterns in nature. Despite a large body of work investigating both geographic and environmental drivers, biogeographical provinces have not been included in statistical models of diversity patterns. Instead, spatial studies tend to focus on species–area and local–regional relationships. Here, we investigate correlates of a latitudinal diversity pattern in Australian coastal molluscs. We use an online database of greater than 300 000 specimens and quantify diversity using four methods to account for sampling variation. Additionally, we present a biogeographic scheme using factor analysis that allows for both gradients and sharp boundaries between clusters. The factors are defined on the basis of species composition and are independent of diversity. Regardless of the measure used, diversity is not directly explained by combinations of abiotic variables. Instead, transitions between regions better explain the observed patterns. Biogeographic gradients can in turn be explained by environmental variables, suggesting that environmental controls on diversity may be indirect. Faunas within provinces are homogeneous regardless of environmental variability. Thus, transitions between provinces explain most of the variation in diversity because small-scale factors are dampened. This explanation contrasts with the species-energy hypothesis. Future work should more carefully consider biogeographic gradients when investigating diversity patterns.

Ecological novelty is emerging rapidly due to global change drivers such as climate shifts, species introductions, defaunation, and land‐use transformation. These changes challenge how we assess, understand and manage ecosystems in the Anthropocene. We present an interdisciplinary framework for analysing the processes that generate novel ecosystems—across biotic and abiotic dimensions, and within their broader social context—rather than focusing solely on identifying novel communities or states. Through this framework, we gain an opportunity to identify ecosystems likely to develop novel properties in the future. The framework distinguishes among four key dimensions of novelty: compositional (species identity and community structure), functional (traits and ecosystem processes), abiotic (environmental conditions) and social (human interactions with, and perceptions of, nature). It accommodates variation in spatial and temporal scale, reference baselines and driver interactions. Our framework emphasises a multi‐process approach, covering different pathways for analysing and understanding many processes measured in a particular location. Designed to be both conceptually robust and operationalisable, the framework supports the development of metrics for monitoring, modelling and conservation decision‐making, applicable to both research and large‐scale ecosystem planning. We integrate perspectives from ecology, conservation biology, paleoecology, archaeology, global change science and the social sciences to guide the development of novel ecosystem research and philosophy. We finally illustrate its application in contexts such as refaunation, assisted migration and adaptive conservation planning. By focusing on novelty‐generating processes, our framework provides a shared foundation for researchers and practitioners to assess, anticipate and manage the emergence of novel ecosystems in an increasingly transformed biosphere.

The “more individuals hypothesis” suggests that increases in the total number of individuals per species leads to increases in community richness. Abundance, body size distributions and richness do vary with latitude in several taxonomic groups. However, support for this hypothesis has otherwise been mixed. In this paper, we investigate latitudinal changes in all three variables for marine bivalves along the eastern coastline of Australia. We utilise a large, uniformly sampled field dataset of 5670 shells representing 157 species that spans 20º of latitude and crosses a major biogeographic transition. For each of 15 field sites, 10 quadrats were randomly placed and completely sampled, making it possible to quantify total abundance. Species richness was calculated using a new estimator based on the geometric series distribution. Body size was computed as the geometric mean of length and width. Despite uncovering a strong latitudinal gradient in species richness, we found no significant gradient in total abundance and body size at any taxonomic level. Although previous work found family-level trends in bivalve size, it was done at a larger spatial scale and therefore did not pertain to individual communities. Environmental variables do correlate with both abundance and richness, but they are not directly related. Because we find no gradient in abundance and no relationship between abundance and richness, we reject the “more individuals hypothesis” for our system. Instead, latitudinal richness trends in coastal Australia may result from an environmental gradient in dispersal constraint.