Data from: Functional and phylogenetic diversity explain different components of diversity effects on biomass production

<p>The Anthropocene is defined by human-driven environmental change, with one consequence being the modern dramatic decline in biodiversity globally. This is especially worrisome given the long-acknowledged causal linkage between biodiversity and ecosystem functioning and the delivery of ecosystem services. <span class="fontstyle01"><span>However, t</span></span>he exact mechanisms driving biodiversity- ecosystem function (BEF) relationships remain unclear, specifically the linkages between species differences, measured by trait and phylogenetic distances, and how interactions, such as competitive inequality and stable coexistence via niche partitioning, influence these relationships.<span class="fontstyle01"><span> Using complementary plant biodiversity experiments, a </span></span>s<span class="fontstyle01"><span>ynthetic-assembled one that combined species in different phylogenetic distance treatments with a semi- natural functional group removal experiment, we assessed how species differences influence the mechanisms underpinning BEF relationships. We </span></span>calculated the net biodiversity effect (ΔY) of biomass production and partitioned it into two additive parts: the complementarity and <span class="fontstyle01"><span>selection effect</span></span>s at species and functional group level<span class="fontstyle01"><span> to </span></span>test how <span class="fontstyle01"><span>phylogenetic diversity and functional</span></span> diversity capture the influences of the complementarity and <span class="fontstyle01"><span>selection effects.</span></span> For both experiments, we found that phylogenetic and functional diversity explained biodiversity effects through similar mechanisms, with a positive relationship with the complementarity effect, and a negative relationship with the selection effect. However, we found that the <span class="fontstyle01"><span>selection effect was </span></span>best predicted by a negative relationship with functional dispersion (FD_is) ofheight where the selection effect was strongest in plots with similarly tall species and weakest with a greater diversity of heights, while higher <span class="fontstyle01"><span>complementary </span></span>effects <span class="fontstyle01"><span>were best explained by increasing phylogenetic diversity (i.e., high MPD_a).</span></span> Our work revealed that the mechanisms underpinning biodiversity-ecosystem function relationships are dependent on species differences and how these differences influence competitive inequalities and niche differences.</p>