A central focus of ecology and biogeography is to determine the factors that govern spatial variation in biodiversity. Here, we examined patterns of ant diversity along climatic gradients in three temperate montane systems: Great Smoky Mountains National Park (USA), Chiricahua Mountains (USA), and Vorarlberg (Austria). To identify the factors which potentially shape these elevational diversity gradients, we analyzed patterns of community phylogenetic structure (i.e. the evolutionary relationships among species coexisting in local communities). We found that species at low‐elevation sites tended to be evenly dispersed across phylogeny, suggesting that these communities are structured by interspecific competition. In contrast, species occurring at high‐elevation sites tended to be more closely related than expected by chance, implying that these communities are structured primarily by environmental filtering caused by low temperatures. Taken together, the results of our study highlight the potential role of niche constraints, environmental temperature, and competition in shaping broad‐scale diversity gradients. We conclude that phylogenetic structure indeed accounts for some variation in species density, yet it does not entirely explain why temperature and species density are correlated.

The evolutionary and environmental factors that shape fungal biogeography are incompletely understood. Here, we assemble a large dataset consisting of previously generated mycobiome data linked to specific geographical locations across the world. We use this dataset to describe the distribution of fungal taxa and to look for correlations with different environmental factors such as climate, soil and vegetation variables. Our meta-study identifies climate as an important driver of different aspects of fungal biogeography, including the global distribution of common fungi as well as the composition and diversity of fungal communities. In our analysis, fungal diversity is concentrated at high latitudes, in contrast with the opposite pattern previously shown for plants and other organisms. Mycorrhizal fungi appear to have narrower climatic tolerances than pathogenic fungi. We speculate that climate change could affect ecosystem functioning because of the narrow climatic tolerances of key fungal taxa.

Aim Whether the gradients of global diversity conform to equilibrium or non‐equilibrium dynamics remains an unresolved question in ecology and evolution. Here, we evaluate four prominent hypotheses which invoke either equilibrium (more individuals, niche diversity) or non‐equilibrium dynamics (diversification rate, evolutionary time) to explain species richness and functional diversity of mammals worldwide. Location Global. Methods We combine structural equation modelling with simulations to examine whether species richness and functional diversity are in equilibrium with environmental conditions (climate, productivity) or whether they vary with non‐equilibrium factors (diversification rates, evolutionary time). We use the newest and most inclusive phylogenetic, distributional and trait data for mammals. Results We find that species richness and functional diversity are decoupled across multiple regions of the world. While species richness correlates closely with environmental conditions, functional diversity depends mostly on non‐equilibrium factors (evolutionary time to overcome niche conservatism). Moreover, functional diversity plateaus with species richness, such that species‐rich regions (especially the Neotropics) host many species that are apparently functionally redundant. Main conclusions We conclude that species richness depends on environmental factors while functional diversity depends on the evolutionary history of the region. Our work further challenges the classic notion that highly productive regions host more species because they offer a great diversity of ecological niches. Instead, they suggest that productive regions offer more resources, which allow more individuals, populations and species to coexist within a region, even when the species are apparently functionally redundant (the more individuals hypothesis). Together these findings demonstrate how ecological (the total amount of resources) and evolutionary factors (time to overcome niche conservatism) might have interacted to generate the striking diversity of mammals and their life histories.

Aim: Many important patterns and processes vary across the phylogeny and depend on phylogenetic scale. Nonetheless, phylogenetic scale has never been formally conceptualized, and its potential remains largely unexplored. Here, we formalize the concept of phylogenetic scale, review how phylogenetic scale has been considered across multiple fields and provide practical guidelines for the use of phylogenetic scale to address a range of biological questions. Innovation:We summarize how phylogenetic scale has been treated in macroevolution, community ecology, biogeography and macroecology, illustrating how it can inform, and possibly resolve, some of the longstanding controversies in these fields. To promote the concept empirically, we define phylogenetic grain and extent, scale dependence, scaling and the domains of phylogenetic scale. We illustrate how existing phylogenetic data and statistical tools can be used to investigate the effects of scale on a variety of well-known patterns and processes, including diversification rates, community structure, niche conservatism or species-abundance distributions.Main conclusions: Explicit consideration of phylogenetic scale can provide new and more complete insight into many longstanding questions across multiple fields (macroevolution, community ecology, biogeography and macroecology). Building on the existing resources and isolated efforts across fields, future research centred on phylogenetic scale might enrich our understanding of the processes that together, but over different scales, shape the diversity of life.

24It has been widely acknowledged that many phenomena in ecology and evolution depend on spatial 25 and temporal scale. However, important patterns and processes may vary also across the phylogeny 26 and depend on phylogenetic scale. Though phylogenetic scale has been implicitly considered in 27 some previous studies, it has never been formally conceptualized and its potential remains 28 unexplored. Here, we develop the concept of phylogenetic scale and, building on previous work 29 in the field, we introduce phylogenetic grain and extent, phylogenetic scaling and the domains of 30 phylogenetic scale. We use examples from published research to demonstrate how phylogenetic 31 scale has been considered so far and illustrate how it can inform, and possibly resolve, some of the 32 longstanding controversies in evolutionary biology, community ecology, biogeography and 33 macroecology. To promote the concept of phylogenetic scale empirically, we propose 34 methodological guidelines for its treatment.Numerous patterns in ecology and evolution vary across the phylogenetic hierarchy ( Fig. 1). 57Species diversity declines with latitude across higher taxa but not necessarily across their 58 constituent families and genera (Kindlman et al., 2007). Phylogenetic delimitation of species pools 59 influences our inferences about the processes that form local communities 60 2009). Many other, similar examples further illustrate that patterns in ecology and evolution often 61 depend on phylogenetic scale ( Fig. 1). Yet, unlike the extensively developed concepts of spatial 62 and temporal scale where scale dependence in the patterns and processes driving variation in 63 diversity has long been acknowledged (Wiens, 1989; Levin, 1992), the importance of phylogenetic 64 scale has only recently begun to be recognized. Here, we formalize and develop the concept of 65 phylogenetic scale, summarize how it has been considered across disciplines, provide empirical 66 guidelines for the treatment of phylogenetic scale, and suggest further research directions. 67 68 Inspired by the concept of spatial scale (Wiens, 1989; Levin, 1992), we define phylogenetic scale 69 in terms of phylogenetic grain and phylogenetic extent (Box 1). Phylogenetic grain refers to the 70 elementary unit of analysis, defined in terms of tree depth, taxonomic rank, clade age, or clade 71 size. Phylogenetic extent refers to the entire phylogeny encompassing all these units. Exploring 72 multiple grains and extents should provide relevant insights about the mechanisms that have 73 produced a pattern of interest. For example, the number of families in the fossil record appears to 74 be constant while the number of genera seems to increase continually over geological time, 75 suggesting that different mechanisms produce genus-level and family-level diversity (Benton & 76 Emerson, 2007). In community ecology, clade-wide analyses typically suggest that communities 77 have been shaped by environmental filters while focused analyses of narrowly defined clades often...

Range size heritability refers to an intriguing pattern where closely related species occupy geographic ranges of similar extent. Its existence may indicate selection on traits emergent only at the species level, with interesting consequences for evolutionary processes. We explore whether range size heritability may be attributable to the fact that range size is largely driven by the size of geographic domains (i.e., continents, biomes, areas given by species' climatic tolerance) that tend to be similar in phylogenetically related species. Using a well-resolved phylogeny of Carnivora, we show that range sizes are indeed constrained by geographic domains and that the phylogenetic signal in range sizes diminishes if the domain sizes are accounted for. Moreover, more detailed delimitation of species' geographic domain leads to a weaker signal in range size heritability, indicating the importance of definition of the null model against which the pattern is tested. Our findings do not reject the hypothesis of range size heritability but rather unravel its underlying mechanisms. Additional analyses imply that evolutionary conservatism in niche breadth delimits the species' geographic domain, which in turn shapes the species' range size. Range size heritability patterns thus emerge as a consequence of this interplay between evolutionary and geographic constraints.

Aim Why some species exhibit larger geographical ranges than others remains a fundamental, but largely unanswered, question in ecology and biogeography. In plants, a relationship between range size and mating system was proposed over a century ago and subsequently formalized in Baker's Law. Here, we take advantage of the extensive variation in sexual systems of liverworts to test the hypothesis that dioecious species compensate for limited fertilization by producing vegetative propagules more commonly than monoecious species. As spores are assumed to contribute to random long-distance dispersal, whereas vegetative propagules contribute to colony maintenance and frequent short-distance dispersal, we further test the hypothesis that monoecious species exhibit larger geographical ranges than dioecious ones.Location Worldwide.Methods We used comparative phylogenetic methods to assess the correlation between range size and life history traits related to dispersal, including mating systems, spore size and production of specialized vegetative propagules.Results No significant correlation was found between dioecy and production of vegetative propagules. However, production of vegetative propagules is correlated with the size of geographical ranges across the liverwort tree of life, whereas sexuality and spores size are not. Moreover, variation in sexual systems did not have an influence on the correlation between geographical range and production of asexual propagules. Main conclusionsOur results challenge the long-held notion that spores, and not vegetative propagules, are involved in long-distance dispersal. Asexual reproduction seems to play a major role in shaping the global distribution patterns of liverworts, so that monoecious species do not tend to display, on average, broader distribution ranges than dioecious ones. Our results call for further investigation on the spatial genetic structure of bryophyte populations at different geographical scales depending on their mating systems to assess the dispersal capacities of spores and asexual propagules and determine their contribution in shaping species distribution ranges.

Aim: Diversity dynamics remain controversial. Here, we examine these dynamics, together with the ecological factors governing them, across mammalian clades of different ages and sizes, representing different phylogenetic scales. Specifically, we investigate whether the dynamics are bounded or unbounded, biotically or abiotically regulated, stochastic or ecologically deterministic. Location: Worldwide.Time period: 150 Myr.Major taxa studied: Mammals.Methods: Integrating the newest phylogenetic and distributional data by means of several distinct methods, we study the ecology of mammalian diversification within a predictive framework, inspired by classic theory. Specifically, we evaluate the effects of several classes of factors, including climate, topography, geographical area, rates of climatic-niche evolution, and regional coexistence between related and unrelated species. Next, we determine whether the relative effects of these factors change systematically across clades representing different phylogenetic scales.Results: We find that young clades diversify at approximately constant rates, medium-sized clades show diversification slowdowns, and large clades are mostly saturated, suggesting that diversification dynamics change as clades grow and accumulate species. We further find that diversification slowdowns intensify with the degree of regional coexistence between related species, presumably because increased competition for regional resources suppresses the diversification process. The richness at which clades eventually saturate depends on climate; clades residing in tropical climates saturate at low richness, implying that niches become progressively densely packed towards the tropics. Main conclusions:The diversification process is influenced by a variety of ecological factors, whose relative effects change across phylogenetic scales, producing scale-dependent dynamics.Different segments of the same phylogeny might therefore support seemingly conflicting results (bounded or unbounded, biotically or abiotically regulated, stochastic or ecologically deterministic diversification), which might have contributed to several outstanding controversies in the field.These conflicts can be reconciled, however, when accounting for phylogenetic scale, which might, in turn, produce a more integrated understanding of global diversity dynamics. K E Y W O R D Sbiogeography, competition, macroevolution, niche, phylogeny 32 |