American Journal of Botany, Journal Year: 2021, Volume and Issue: 108(4), P. 549 - 552

Published: April 1, 2021

Although botanists have been at the center of invasion biology since its inception, few identify as biologists. Of those few, many primarily ally with associated disciplines such weed science and agronomy. The modern field biology—the study introduction, establishment, evolution, control non-native species—was formally established when zoologist Charles Elton proposed his biodiversity-invasibility hypothesis (Elton, 1958) has largely dominated by zoologists. However, plants proven to be tractable systems for both experimental observational studies played an outsized role in addressing long-standing hypotheses (Fig. 1). Here, we briefly review historic contemporary contributions that made argue will continue play a critical revolutionizing biology. work on plant invasions arguably began 17th century Linneaus protégé, Pehr Kalm, first noting naturalized European species North America. Early naturalists including Lyell, Alfred Russel Wallace, Darwin commonly observed (Simberloff, 2013); Darwin's naturalization hypothesis, one attempts understand process, use these observations. Twentieth like Baker George Ledyard Stebbins avoided terminology biology, but studied colonizations natural evolutionary experiments helped merge synthesis (Barrett, 2015). In 1980s 1990s, consequential roles understanding invasibility, inferring population dynamics underlying invasions, studying consequences across communities, food webs, ecosystems (Levine et al., 2003; Pyšek Richardson, 2007). Many leveraged tractability (i.e., immobility, flexible reproductive strategies, easy propagation within manipulative experiments)—traits make uniquely pragmatic models research today. Genetic analyses during 2000s overturned assumptions dynamics, revealing introductions are often repeated, admixture is frequent, selection common (Dlugosch Parker, 2008; Colautti Lau, Recently, advances genomics provided more nuanced process. Below, highlight four areas where suited recently biology: colonization admixture, hybridization, plasticity. Rather than simply determining whether stem from single or multiple events, recent genomic begun untangle complex spatial temporal context colonization. For example, Mimulus guttatus DC. United Kingdom was once assumed result introduction Alaskan population. reveal there were several genetically distinct native American populations time points (Vallejo-Marín 2021). Invasions may lead future events. Recent Ambrosia artemisiifolia L. documented "bridgehead" effects invasive area led into second region (van Boheemen 2017; Vallejo-Marín emerging consensus dynamic ongoing process can repeatedly replenish alter genetic diversity throughout invasion. Unlike early suggested depauperate, show equal greater levels within-population their range compared range. Increased introduced due among previously isolated Furthermore, suggest novel variants ecologically important (Keller Taylor, 2010). Hybrids between Phalaris arundinacea fitness (Lavergne Molofsky, 2007), driven local adaptation Spartina alterniflora Loisel. China (Qiao 2019). Native Plantago lanceolata subject ecological constraints do not affect admixed (Smith 2020). These preadapted environment evolve phenotypic novelty through admixture. Novel variation also interspecific hybridization polyploidy (Whitney 2009; te Beest 2012). instance, Sorghum halepense Pers. cultivated bicolor (L.) Moench resulted introgression loci traits rhizome growth seed size likely facilitated S. southeastern States (Paterson Polyploidy, presence two genome copies per cell, concomitant prevalent other taxa. Such duplication increase heterozygosity, facilitate selfing, plasticity, all which promote invasibility (te Scotland, polyploidization ranges separate continents generated individuals phenotypically divergent parent (Meeus Going forward, mechanistic details link gene dosage phenotype needed exactly how invasibility. Plant provide evidence importance plasticity mechanisms increased (Sultan 2013; Bock 2018). successful establishment Helianthus tuberosus riparian Europe clonality enhanced vegetative tuber formation, plastic response water availability evolved further (Bock epigenetic hints additional generating facilitating particularly asexual invaders Salvinia molesta Fallopia japonica (Mounger press [Preprint]). genome-wide surveys grown controlled greenhouse reciprocal transplant DNA methylation far higher (Richards 2012), potentially promoting success diverse habitats. epigenetics direction ripe unanswered questions. examples above demonstrate significant making well poised overcome some hurdles long encumbered field. A major challenge timing strengths different forces trajectory speed. Much difficulty this stems sampling limitations; inferences regarding extent bottlenecks, prevalence magnitude typically comparisons only period. processes spread requires repeated course Botanists advantages implementing approach. First, strong cooperation herbaria, abundant collections, robust digitization databasing efforts samples spanning access. Second, increasing community observations relative ease locating resampling specific allows quickly ascertain, revisit, collect forefront invasions. Combining herbarium collections techniques unparalleled assessment changes entire While used generate data any species, herbaria tend plentiful because conspicuous, abundant, collector. library design enable reduced-representation sequencing small quantities degraded preserved (e.g., Suchan 2016), evaluation tractable. limitations terms regional bias lack same locations, approach greatly expand our ability varied environments Efforts apply five focal currently being coordinated Consortium INvasion Genomics (CPING, www.invasiongenomics.com). Genomic nascent similar time-course sets while better allowing investigators design. identifying potential difficult require decades investment track sample fronts. disadvantages mitigated integrating botanical databases initiatives iNaturalist soon after new vanguard relatively researchers validate sessile unlikely become extirpated. Continuous tracking useful information about rate velocity spread. summary, always testing tools. Plants allow address questions By embracing leveraging knowledge, historical resources, technologies, revolutionize species. Funding NSF grant OIA-1920858 C.F.B., J.B.B., M.L., M.R.M., E.M.S., N.J.K. We thank anonymous reviewers Pamela Diggle comments improved article. Brittany L Sutherland: Writing – original draft (equal); & editing (equal). Craig F Barrett: James B Beck: Maribeth Latvis: Michael R McKain: Erin M Sigel: Nicholas J. Kooyers: All authors contributed drafting revision manuscript. Data Fig. 1 available Dryad Digital Repository: https://doi.org/10.5061/dryad.g1jwstqqg (Kooyers

Language: Английский