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This chapter explores the taxic and phylogenetic estimates of sauropod diversity. It specifically provides the alternative estimates of sauropod lineage diversity and evaluates the implications of these diversity patterns for the understanding of sauropod evolutionary history and sampling biases. The advantages and disadvantages of taxic diversity estimate (TDE) and phylogenetic diversity estimate (PDE) are explained. The impact of sampling biases might be evaluated by determining whether the opportunities to observe/collect specimens have remained approximately evenly distributed across time. Down-weighting strategies do not offer any real benefits, and in some cases such approaches will be more misleading than a simple equally weighted strategy. Sauropod diversity fluctuated considerably during their evolution, with major radiations occurring during the Middle and Late Jurassic. It is also clear that the sauropod fossil record has been affected by sampling biases, most notably in the early part of the Middle Jurassic and the Turonian-Coniacian.

This chapter examines how phylogenetic diversity changes across spatial and temporal gradients. Spatial ecophylogenetic patterns can reveal how different processes shape ecological communities. Metacommunity ecology reinvigorated the search for general mechanisms that create diversity and structural differences among communities, and by using phylogenetic patterns we can understand how shared traits and evolution inform community differences. The chapter first considers phylobetadiversity as a measure of phylogenetic turnover before discussing two types of phylobetadiversity metrics, diversity partitioning and pairwise distances. It also analyzes the influence of spatial scale on phylogenetic patterns, focusing on the scale dependency of phylogenetic patterns, and concludes with an overview of phylogenetic diversity–area relationships.

This chapter examines the use of phylogenetic methods to explain macroevolutionary trends in speciation, extinction, and the distribution of phylogenetic diversity across space and through time. The diversity of life is unevenly distributed across the globe. Species richness tends to be higher at lower latitudes and elevations, and the distribution of life forms also varies across space. For example, Foster's rule suggests that on islands small species evolve to become bigger, while large species evolve to become smaller. Equally, the distribution of evolutionary history shows large spatial variation, reflecting the histories of speciation, extinction, and dispersal. This chapter first considers how large, global phylogenies make it possible to map the distribution of phylogenetic diversity and develop a conservation strategy to maximize coverage of the tree of life. It then discusses the variation in diversification across spatiotemporal gradients and shows that phylogenetic diversity covaries significantly with taxonomic richness.

The assembly rules which determine the composition of communities are based on the hypothesis of combined effects of different environmental filters on the regional pool of individuals: stochastic dispersal events determine which species are potentially available; local abiotic conditions select for species able to tolerate these conditions; and biotic effects determine the coexistence of interacting species. The functional structure of a community, i.e. the distribution of trait values, can be quantified by the community weighted mean of a trait and indices of functional divergence. It varies as a function of the relative importance of filters. When the abiotic filter selects individuals on the basis of their tolerance of resource availability, this leads to a restriction in the range of trait values relevant to resource use, and a convergent distribution with little dispersion around the mean. When this filter is linked to disturbance, it can lead to an over-dispersion or divergence of trait values, especially those linked to regeneration. The biotic filter can have contrasting effects on trait distributions, depending on the relative importance of the limiting functional similarity and competitive exclusion. The functional structure of a community depends on the intra- and interspecific variability of traits, whose relative importance varies with spatial scale. The structure of a community can also be described by assessing the phylogenetic diversity. Assuming that closely related species have more similar trait values than distantly related species, the chapter discusses whether the phylogenetic structure of a community can be used to infer its functional structure.

This chapter explains how phylogenetic information can be used to make better conservation decisions. Evidence shows that human-caused climate change is likely to be the dominant cause of extinction in the near future. Phylogeny can provide a powerful tool for aiding decision making in species conservation. The chapter first considers the importance of preserving evolutionary history by focusing on the tree of life, the phylogenetic tree connecting all living organisms that provides a powerful metaphor for conservation biology. It then examines phylogenetically based metrics for quantifying evolutionary history, including phylogenetic diversity for evaluating sites and evolutionary distinctiveness for comparing species. It also discusses the integration of evolutionary history with extinction probabilities for conservation prioritization using relative extinction risk to weight evolutionary distinctiveness, or EDGE (evolutionarily distinct and globally endangered). Finally, it describes how to prioritize biodiversity hotspots of evolutionary distinctiveness and how to apply metrics to conservation prioritization.

Mechanisms of abiotic environmental factors influencing basic community properties like standing biomass, productivity, species diversity, structure, fluctuations, persistence, and resilience are discussed on the global, regional, and local spatial scales, encompassing timescales from the ecological to the evolutionary. The geographic distribution of species diversity and of plant strategies is related to environmental conditions, mainly to light and water availability. Effects of diversity on ecosystem functioning are addressed through comparative and experimental studies. The effects of species pool size and composition—which have evolved on an evolutionary timescale—are also considered in relation to their influence on the composition and the dynamics of communities at the ecological timescale. Finally, possible causes of the changes in community composition (β‎-diversity) are discussed, exemplifying the role of self-organizing patterns and alternative stable states.