Summary• Phenotypic and genetic clines have long been synonymous with adaptive evolution. However, other processes (for example, migration, range expansion, invasion) may generate clines in traits or loci across geographical and environmental gradients. It is therefore important to distinguish between clines that represent adaptive evolution and those that result from selectively neutral demographic or genetic processes.• We tested for the differentiation of phenotypic traits along environmental gradients using two species in the genus Silene, whilst statistically controlling for colonization history and founder effects. We sampled seed families from across the native and introduced ranges, genotyped individuals and estimated phenotypic differentiation in replicated common gardens.• The results suggest that post-glacial expansion of S. vulgaris and S. latifolia involved both neutral and adaptive genetic differentiation (clines) of life history traits along major axes of environmental variation in Europe and North America. Phenotypic clines generally persisted when tested against the neutral expectation, although some clines disappeared (and one cline emerged) when the effects of genetic ancestry were statistically removed.• Colonization history, estimated using genetic markers, is a useful null model for tests of adaptive trait divergence, especially during range expansion and invasion when selection and gene flow may not have reached equilibrium.

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To successfully reduce overall invasive plant cover over time, an effective treatment plan must be established such that mortality exceeds new colonization and re-spouting growth rates. However, few evaluations of the effects of long-term, consistent treatment at different intervals exist. We report the effects of treatment intensity on Old World climbing fern (Lygodium microphyllum (Cav.) R. Br.), Brazilian pepper (Schinus terebinthifolia Raddi) and punktree (Melaleuca quinquenervia (Cav.) S. T. Blake), as part of a large restoration project that has been underway for six years in Telegraph Swamp at Babcock Ranch Preserve, a 68,000 acre conservation area in Florida, U.S.A. We found that at the end of the six-year period, for all three species, average live cover did not exceed 5% across all transects. In addition, dead foliar cover was higher than live cover for all three invasive plants, indicating progress towards restoration goals. We also found that percent live cover of Old World climbing fern were significantly reduced only after four or more treatments were applied during the six-year period, as opposed to when three or fewer treatments were applied. Reductions in percent cover of live foliage were apparent only when the treatments were applied more often than biennially, as opposed to less often than biennially. Additionally, we found higher Old World climbing fern cover in clear-cut and replanted cypress stands than in natural stands. Based on these findings, we conclude that treatments applied four or more times, or more often than biennially, were more effective at significantly reducing advanced invasions of Old World climbing fern, Brazilian pepper, and punktree, especially where previous management activities or their effects may have increased the cover of invasive plants.