bioinformatics; Brownian motion model; comparative analysis; data mining; realized environmental niche; general linear models; geographic information systems; invasive plants; macroevolution; maximum likelihood; niche dynamics; Ornstein-Uhlenbeck process; phylogenetics; plant functional traits; species distribution models; generalized estimating equations; climatic niche; niche conservatism; niche shift; Hutchinsonian niche
D'Amen M, Zimmermann NE, Pearman PB (2013), Conservation of phylogeographic lineages under climate change, in GLOBAL ECOLOGY AND BIOGEOGRAPHY
, 22(1), 93-104.
Broennimann O, Fitzpatrick MC, Pearman PB, Petitpierre B, Pellissier L, Yoccoz NG, Thuiller W, Fortin MJ, Randin C, Zimmermann NE, Graham CH, Guisan A (2012), Measuring ecological niche overlap from occurrence and spatial environmental data, in GLOBAL ECOLOGY AND BIOGEOGRAPHY
, 21(4), 481-497.
Engler R, Randin CF, Thuiller W, Dullinger S, Zimmermann NE, Araujo MB, Pearman PB, Le Lay G, Piedallu C, Albert CH, Choler P, Coldea G, De Lamo X, Dirnbock T, Gegout JC, Gomez-Garcia D, Grytnes JA, Heegaard E, Hoistad F, Nogues-Bravo D, Normand S, Puscas M, Sebastia MT, Stanisci A, Theurillat JP (2011), 21st century climate change threatens mountain flora unequally across Europe, in GLOBAL CHANGE BIOLOGY
, 17(7), 2330-2341.
Pearman PB, Guisan A, Zimmermann NE (2011), Impacts of climate change on Swiss biodiversity: An indicator taxa approach, in BIOLOGICAL CONSERVATION
, 144(2), 866-875.
Salamin N, Wuest RO, Lavergne S, Thuiller W, Pearman PB (2010), Assessing rapid evolution in a changing environment, in TRENDS IN ECOLOGY & EVOLUTION
, 25(12), 692-698.
Pearman PB, D'Amen M, Graham CH, Thuiller W, Zimmermann NE (2010), Within-taxon niche structure: niche conservatism, divergence and predicted effects of climate change, in ECOGRAPHY
, 33(6), 990-1003.
Ecologists seek to understand the factors that lead some exotic plant species to become ecologically dominant and widespread. This attention is justified because these invasive species can alter community composition, impact ecosystem function, affect species’ evolutionary trajectories, and lead to species extinctions. Despite these impacts, finding characteristics that are consistently shared by invasive species is difficult. The climatic niche of plants (the climatic conditions under which population growth is positive) potentially facilitates plant invasions. Some groups of invasive plants have native ranges that span large latitudinal gradients. Other invasive species have experienced shifts of climatic niche during the invasion process. Niche shifts, both recent and deep in species evolutionary history, likely influence whether immigrant species become established, naturalized and, subsequently, invasive. The evolutionary dynamics of the climatic niche, per se, have seen very little work and there is substantial disagreement over the occurrence, magnitude and rate of climatic niche shifts. These evolutionary niche dynamics are the focus of this proposal.The main goal of this project is to understand the influence of evolutionary history, especially the history of shifts of the climatic niche, on the invasiveness of exotic species. Studying the evolutionary history of niche dynamics is not specific to invasive species. Invasive species are a convenient set of model systems (i.e. genera) in which the literature suggests that it is likely that evolution of the climatic niche influences the presence of a detectable ecological quality: invasiveness. Without the criterion of presence of invasives, we could have selected genera at random or used other criteria that would not likely lead the research to have similarly broad interest. In this research we: (a) use a bioinformatics approach to obtain existing data on species distribution and molecular variation within genera that contain invasive species; (b) modify and use existing software to test the degree to which alternative evolutionary models suffice in describing phylogenetic patterns of niche evolution within these genera; (c) test for evolutionary and historical correlates of niche shift and invasiveness by drawing on information from phylogenetic reconstructions, functional traits, and climatic niche characteristics of species.The first part of the work focuses on collection of (a) ecological, occurrence, and climate data that describe the distribution-climate relationships of species, (b) data on species functional traits, and (c) existing sequence data for phylogeny reconstructions. We extract species distribution data from online databases and a wide array of other data sources, including the primary literature. We obtain molecular data directly from GenBank. Additionally, plant tissue for additional sequencing will be collected at national herbaria and botanical gardens. We model and quantify niche optima and limits using species distribution models and we construct phylogenetic trees of species. We model the evolution of the climatic niche using existing open-source software, examining potential effects of both selection and random evolution on niche variability. We produce a supertree of the genera and, using both niche and functional trait data, develop general linear models to examine the relationship of these variables to establishment and invasion by exotic species. Finally, we expand existing software to examine how heterogeneous selection among subclades affects the likelihood of niche shifts and species invasiveness. Beyond the importance of understanding the factors that contribute to species invasiveness, this research will contribute to understanding how niche shifts contribute to evolution within genera and affect species distributions. By using genera that include invasive species in Switzerland and elsewhere, the project will contribute to efforts to identify potentially invasive species before they become introduced. We will gain better understanding of the role of selection and random evolution in niche shifts of invasive species, closely related species, and their ancestors. By helping us to understand the evolutionary history of niche shifts, this research will improve confidence in the use of species distribution models to predict the potential distributions of invasive species. Finally, understanding evolutionary processes that enable species to expand into new environments may help to predict more accurately the impacts of climate change on plant biodiversity.