Plant diversity increases with the strength of negative density dependence at the global scale.
Joseph A LaMannaScott A ManganAlfonso AlonsoNorman A BourgWarren Y BrockelmanSarayudh BunyavejchewinLi-Wan ChangJyh-Min ChiangGeorge B ChuyongKeith ClayRichard ConditSusan CordellStuart J DaviesTucker J FurnissChristian P GiardinaI A U Nimal GunatillekeC V Savitri GunatillekeFangliang HeRobert W HoweStephen P HubbellChang-Fu HsiehFaith M Inman-NarahariDavid JaníkDaniel J JohnsonDavid KenfackLisa KorteKamil KrálAndrew J LarsonJames A LutzSean M McMahonWilliam J McSheaHervé R MemiagheAnuttara NathalangVojtěch NovotnýPerry S OngDavid A OrwigRebecca OstertagGeoffrey G ParkerRichard P PhillipsLawren SackI-Fang SunJ Sebastián TelloDuncan W ThomasBenjamin L TurnerDilys M VelaTomáš VrškaGeorge D WeiblenAmy WolfSandra YapJonathan A MyersPublished in: Science (New York, N.Y.) (2018)
Theory predicts that higher biodiversity in the tropics is maintained by specialized interactions among plants and their natural enemies that result in conspecific negative density dependence (CNDD). By using more than 3000 species and nearly 2.4 million trees across 24 forest plots worldwide, we show that global patterns in tree species diversity reflect not only stronger CNDD at tropical versus temperate latitudes but also a latitudinal shift in the relationship between CNDD and species abundance. CNDD was stronger for rare species at tropical versus temperate latitudes, potentially causing the persistence of greater numbers of rare species in the tropics. Our study reveals fundamental differences in the nature of local-scale biotic interactions that contribute to the maintenance of species diversity across temperate and tropical communities.