Lag times and invasion dynamics of established and emerging weeds: insights from herbarium records of Queensland, Australia

Abstract Herbarium records provide comprehensive information on plant distribution, offering opportunities to construct invasion curves of introduced species, estimate their rates and patterns expansions in novel ranges, as well identifying lag times hence “sleeper weeds”, if any. Lag especially have rarely been determined for many including weeds the State Queensland, Australia trait is thought be unpredictable cannot screened for. Using herbarium (1850–2010), we generated various invasiveness indices, developed simple standardised proportion changes distribution with time ~ 100 established emerging weed species Queensland. Four major periods (decades) increased spread (spikes) were identified: 1850s, 1900–1920, 1950–1960 2000–2010, grasses trees/shrubs. Many spikes did so only 1–2 decadal times, except a few higher spike frequencies > 6; majority these occurred recently (1950–1990). A significant (~ 60%) Queensland’s exhibit non-linear increase time, phases (mean: 45.9 years; range: 12–126 years); lag-phase 39% are “sleeper” 50 years (mainly trees/shrubs grasses). Twelve traits invasiveness, species-specific/historical factors screened, which frequency waves, residence main drivers weeds’ distribution. The low predictive power suggests that retrospective analyses offer little hope robust generalisation identify tomorrow.