The anthropogenic spread of disease from captive to wild amphibian populations (referred to as spillover) is linked to global amphibian declines. Disinfecting procedures and protocols exist to mitigate pathogen transmission to and within natural areas, but understanding of visitor attitudes and behaviour regarding their adoption is limited. We surveyed visitors in two natural areas in a global amphibian biodiversity hotspot to assess their attitudes regarding pathogen spread in such areas and analysed the factors influencing their behavioural intentions to take specific actions to prevent pathogen spillover. Visitors’ willingness to take action was influenced by their attitudes, behavioural control and trust in wildlife/land managers, whereas socio-demographic characteristics were less influential. These findings help us to understand visitor behaviour with respect to amphibian biosecurity in natural areas and inform enhanced biosecurity measures and strategic messaging to reduce pathogen spillover.

Old World climbing fern [Lygodium microphyllum (Cav.) R. Br] is a smothering vine that has invaded thousands of hectares of wetlands in southern and central Florida, including the Everglades. For more than two decades, the standard management approach in natural areas has been to cut the vines at waist height, leaving climbing rachis to desiccate in the tree canopy (poodle cutting) and subsequently treat all rooted ground cover with a foliar application of a 3% v/v solution of glyphosate. While this is generally effective, there is increasing interest in providing additional control options and more selective treatments. Along with glyphosate, triclopyr is widely used in invasive plant management and may also provide increased selectivity when treating the ground cover. However, it has not been well tested on L. microphyllum, especially the more recently developed acid and choline formulations. In a series of field trials, we compared the acid, amine, and choline formulations of triclopyr against glyphosate as a positive reference and nontreated plots as a negative reference based on control of L. microphyllum at three wetland sites in southern Florida over the period of 2016 to 2020. Significant reductions in L. microphyllum cover were measured at 1 mo after treatment (MAT) and continued to the termination of the studies at 12 and 28 MAT. We found all three triclopyr formulations applied with a single-nozzle backpack sprayer at 5.4 g ae L−1 provided comparable activity to glyphosate applied at 14.4 g ae L−1. There were few differences in L. microphyllum efficacy among the three triclopyr formulations at each site. These results indicate that triclopyr is a suitable alternative to glyphosate for L. microphyllum control in wetland ecosystems. Future research should evaluate triclopyr efficacy on L. microphyllum in varied hydrologic conditions to better refine treatment prescriptions for wetlands.

The invasive vine black swallowwort [Vincetoxicum nigrum (L.) Moench = Cynanchum louiseae Kartesz & Gandhi, Apocynaceae] is difficult to control, and herbicide studies are lacking. This long-lived perennial species is primarily found in high-light environments in natural areas and perennial cropping systems in northeastern North America. We conducted a 3-yr herbicide efficacy study, with or without mowing, in an old-field site infested with V. nigrum in Dutchess County, NY, USA. Experimental plots were either herbicide treated in early July or mowed in early July and subsequently herbicide treated in late August for 2 yr with the potassium salt of glyphosate (2.02 kg ae ha−1), the isopropylamine salt of glyphosate (1.35 kg ae ha−1), or the butoxyethyl ester of triclopyr (1.79 kg ae ha−1). Both glyphosate formulations were effective in reducing V. nigrum aboveground biomass, although they were somewhat less effective in reducing cover or stem densities of V. nigrum plants >10-cm tall after 2 yr compared with untreated plots. Mowing did not always enhance the efficacy of foliar glyphosate applications. Triclopyr, with or without mowing, was generally not effective against V. nigrum in our study. The only significant effect of triclopyr was to increase the cover of grasses in the plots. While annual applications of glyphosate can be useful for management of V. nigrum infestations, higher rates and more frequent applications of triclopyr need to be investigated to determine its usefulness for V. nigrum control.

Pale swallowwort [Vincetoxicum rossicum (Kleopow) Barbar.; syn.: Cynanchum rossicum (Kleopow) Borhidi] and black swallowwort [Vincetoxicum nigrum (L.) Moench; syn.: Cynanchum louiseae Kartesz & Gandhi] are invasive perennial viny milkweeds that have become prevalent across natural and managed habitats in northeastern North America. Southern blight of V. rossicum caused by the fungus Athelia rolfsii (Curzi) C. C. Tu & Kimbr. was reported at a New York county park in 2008, resulting in a decline in V. rossicum stands. The disease outbreak and persistence of the pathogen highlighted the potential of A. rolfsii for Vincetoxicum spp. control. To better characterize A. rolfsii’s pathogenicity and biology, we studied virulence to adult Vincetoxicum spp., spatiotemporal attributes of the Southern blight epidemic at the discovery site over 4 yr, and sclerotial survival over 2 yr. Disease incidence and severity were high for both Vincetoxicum spp. in misting chamber experiments. The spatiotemporal spread patterns of Southern blight in V. rossicum suggest the epidemic in the first year of monitoring (2016) was already highly aggregated and that subsequent spread was limited and resulted in significant local aggregation. Sclerotial survival studies at two locations (Pittsford and Ithaca, NY) demonstrated the A. rolfsii isolates can overwinter in upstate New York and are pathogenic to Vincetoxicum spp. the subsequent season. However, shallow burial of sclerotia more rapidly reduced survival compared with placement on the soil surface. Overwinter survival of A. rolfsii sclerotia in New York is notable, as this pathogen is typically associated with subtropical and tropical regions. Broadcast applications of the pathogen would be needed for widespread Vincetoxicum control at a site, but even restricting releases to select locations would not prevent pathogen movement off-site via water or machinery. The known risks of the A. rolfsii isolate to other broadleaf plants in natural and agricultural settings suggest a low feasibility of use for the biological control of Vincetoxicum spp.

The publication of the RurLand (Rural Landscape in North-East Gaul) project has provided an opportunity to compare methodologies and results with those of The Rural Settlement of Roman Britain project. Two themes, which draw out the asymmetrical development of settlement in the two regions, are examined: the very different impacts of the Roman conquests of Gaul and of Britain on settlement numbers and settlement continuity, and the development of the agricultural economy and its relationship with the frontiers of Britain and Germany, as reflected in the growth and decline of villa estates in Britain and Gaul.

Pale swallowwort (Vincetoxicum rossicum), as well as its congener, black swallowwort (Vincetoxicum nigrum), is a European viny milkweed that has become invasive in natural areas and perennial cropping systems in the northeastern and midwestern United States and southeastern Canada. Mechanical control over 1 to 2 yr has not been effective, but studies of a longer duration are needed. We measured effects of mowing (no mowing or three or six times per growing season) on stem and root crown densities, percent cover, and follicle (seed pod) production of V. rossicum and percent cover of other vegetation over a 7-yr period. Stem density, root crown density, and percent cover of V. rossicum were reduced after 3 to 5 yr of mowing regardless of mowing frequency. Cover of other, mostly nonnative, broadleaf species increased. Follicle production was eliminated in all years of the study. In our environment, mowing three times at monthly intervals during the growing season can prevent seed production. However, mowing must occur for at least 3 yr to reduce, but not eliminate, stands of V. rossicum.

We evaluated herbicide treatments for control of umbrella dracaena, locally invasive in central Florida. Biannual treatments of imazapyr (3.2 and 6.4 g ai L−1), metsulfuron (0.08 and 0.16 g ai L−1), and imazapyr (0.8 g ai L−1) plus glyphosate (19.9 g ai L−1) reduced cover to < 3% at 12 mo, but no treatment eliminated the plant. In contrast, a single treatment on individual potted plants in greenhouse trials was highly effective with ≥ 98% necrosis/chlorosis at 6 mo and no regrowth at 9 mo posttreatment for most treatments. Management of umbrella dracaena will require more than two herbicide treatments with imazapyr, metsulfuron, glyphosate, or a combination of these herbicides if eradication is to be achieved. Because it is currently problematic and localized in one specific area in about 40 ha, it should be a high management priority before it spreads throughout Florida and possibly other states.

Dioscorea oppositifolia (Chinese yam) is an exotic perennial vine invading natural areas in the temperate regions of the eastern United States. Rapid early-season growth of D. oppositifolia is facilitated by an extensive tuber system. Plants can reach heights greater than 370 cm, as the plants climb trees and other vegetation. Shoot length increased 3.6 cm/d from late May to mid-August under field conditions, and primary and secondary tuber length increased 0.28 and 0.2 cm/d, respectively. This indicated rapid vegetative growth and substantial food reserves to form new plants in subsequent years. Dioscorea oppositifolia plants also formed aerial bulbils of 0.8- to 1.2-cm diameter, which are important in dissemination of the species over geographical areas. A field study indicated incomplete control from manual removal, clipping by hand, or glyphosate (2% v/v) application to control D. oppositifolia, although glyphosate was the most effective. Additionally, the use of herbicides was more efficient from a time-utilization perspective than either manual removal or clipping. In a separate study, glyphosate application at flowering was more effective in reducing D. oppositifolia growth the year after application as compared with glyphosate applications soon after emergence. Under greenhouse conditions, however, glyphosate at 0.84 kg ae/ha provided <15% control. The ester formulation of triclopyr at 2.5 kg ai/ha provided >90% D. oppositifolia control. Metsulfuron provided 31% control, and mesotrione provided 36% control and at higher rates may reduce D. oppositifolia growth. Several other herbicides having diverse modes of action provided minimal control of D. oppositifolia.

Black and pale swallowwort (BSW and PSW, respectively) are perennial, herbaceous vines in the Apocynaceae that are native to Europe. The species are becoming increasingly abundant in the northeastern United States and southeastern Canada and are difficult to manage. However, we know little about the demographic parameters of these species. We determined the survival, annual rate of vegetative growth, and fecundity of mature clumps of these swallowwort species. We selected four PSW sites (three of which comprised both old-field and forest habitats) in central New York and three BSW old fields in southeastern New York. BSW is largely restricted to higher light habitats in its introduced range. In each habitat, we followed the growth of 30 to 32 randomly selected clumps of similar size (2 to 5 stems clump−1 in the initial year) for 3 to 4 yr. Yearly survival was 99.6 ± 0.3% [mean ± standard error] for PSW and 100 ± 0% for BSW. In old fields, vegetative expansion varied from −0.01 ± 0.1 to 4.6 ± 0.4 stems clump−1 yr−1 for BSW and −0.02 ± 0.2 to 2.1 ± 0.5 stems clump−1 yr−1 for PSW. In forests, PSW growth was lower with vegetative expansion ranging from −0.01 ± 0.1 to 0.8 ± 0.2 stems clump−1 yr−1. Fecundity of PSW in 2007 and 2008 (130 ± 10 viable seeds stem−1 yr−1) was similar to BSW (100 ± 10 viable seeds stem−1 yr−1). Fecundity of PSW in forests was generally lower than PSW in old fields, but it varied greatly among sites (0 to 170 viable seeds stem−1 yr−1). We found that stem growth and fecundity did not vary with clump size (stems per clump). Since vegetative expansion and fecundity rates were high in old-field habitats, but were generally low or nonexistent in forest habitats, we suggest that management of these two invasive vines be focused in higher light environments to reduce overall seed production and its subsequent spread to surrounding areas.

Japanese climbing fern (Lygodium japonicum) is an invasive vine that has been identified as an economic and ecological threat in forest ecosystems of the Southeast. In two separate studies, we examined the use of directed sprays of glyphosate, imazapyr, and metsulfuron-methyl herbicides, alone and in combination, for control of Japanese climbing fern and for impacts to associated vegetation in mixed bottomland hardwood–cypress forests at two first terrace sites of the Apalachicola River in north Florida. Two yr after treatment, various rates of glyphosate alone generally provided greater percent control (84 to 95%) than imazapyr alone (−25 to 86%) or metsulfuron-methyl alone (−5 to 53%). Combinations of 2% glyphosate and imazapyr and/or metsulfuron-methyl resulted in 81 to 97% control at 2 yr after treatment, with no significant differences among the combination treatments or 2% glyphosate alone. Change in percent cover of associated vegetation groups was not influenced by treatment except for one location where graminoid cover increased 1 yr after metsulfuron-methyl treatment but decreased after imazapyr or glyphosate application. Species richness of dominant understory vegetation remained nearly constant at both locations regardless of treatment. These data indicate that glyphosate alone or in combination with imazapyr or metsulfuron-methyl will provide effective, although not complete, control of Japanese climbing fern, and that directed herbicide sprays minimally impact nontarget vegetation.

Old World climbing fern is one of the most invasive plants in natural areas of central and southern Florida. The fern spreads across the landscape by wind-blown spores and invades isolated and undisturbed habitats such as interior portions of the Florida Everglades. Land managers in Florida have reported that multiple herbicide treatments are required to control the fern, which could indicate that herbicides do not translocate throughout the plant in long-established populations. We conducted a greenhouse study to determine the absorption and translocation patterns in Old World climbing fern using the three herbicides most commonly used for management of this plant by land managers in Florida. Using 14C-labeled herbicides, we evaluated absorption and translocation of glyphosate (2.25 kg ai ha−1), metsulfuron (0.10 kg ai ha−1), and triclopyr (1.68 kg ai ha−1) in Old World climbing fern using five different application scenarios (cut-and-spray, basal spray, 25% foliar spray, 50% foliar spray, and 100% foliar spray). Triclopyr was absorbed to the greatest extent (60.3%) of applied radioactive compounds compared to glyphosate (31.2%) and metsulfuron (19.8%). The majority of radioactivity remained in treated leaves for all herbicides with only small percentages of the absorbed radioactivity being detected in other plant parts. All three herbicides translocated acropetally and basipitally to some extent. Radioactivity, for the most part, translocated evenly throughout the plants but the greatest amount of radioactivity derived from triclopyr occurred in rhizomes when the cut-and-spray and basal applications were used. The radioactivity in rhizomes derived from glyphosate was greater in those treated using cut-and-spray. Based on autoradiographs, there was limited horizontal movement of any herbicide in the rhizomes of Old World climbing fern which could explain why resprouts are observed several weeks following treatment.

Old World climbing fern (OWCF) spores had lower germination rates (P = 0.0072) after being frozen for ≥ 3 h compared to < 3 h, and were highly susceptible to freezing periods ≥ 6 h with a 5.8- to 13.3-fold reduction in spore germination compared to controls. Freezing temperature did not affect germination of Japanese climbing fern (JCF) spores compared to controls (P = 0.32). OWCF gametophytes had reduced survival at all exposures to freezing temperatures compared to controls (P < 0.0001), and had < 0.5% survival for exposure times ≥ 3 h. The gametophytes of JCF had reduced survival at exposures to freezing temperatures ≥ 1 h (P < 0.0001) compared to controls. JCF gametophyte survival was 52.5% at 3-h exposure time, but was reduced to ≤ 0.1% at exposure times ≥ 6 h. All OWCF sporophytes exhibited 100% necrosis for all exposure times 24 h postexposure, but new growth from resprouts was observed for exposure time ≤ 6 h at 6 mo postfreezing. OWCF sporophytes' dry weight biomass was greatly reduced for all exposure times compared to controls (P < 0.0001). Results with nonlinear regression (P < 0.0001, R2 = 0.92) indicated that a single freeze for 2.4 h at −2.2 C reduced OWCF dry weight biomass to 0.01 g, a 10-fold reduction, at 6 mo postfreezing. These results indicate that JCF spores and gametophytes are more tolerant of longer exposure periods to freezing temperatures than OWCF, but OWCF exhibited the potential to spread further into northern Florida.

The European vines pale swallowwort and black swallowwort are invading various habitats in northeastern North America. It is unclear how these plants might respond to potential biological control agents, as they experience little herbivore damage in North America, or longer durations of mowing given the reported lack of efficacy of mechanical control. We evaluated the effect of six seasons of artificial defoliation (50 or 100% defoliation once or twice per season) and clipping (once, twice, or four times at 8 cm above the soil level) on the survival, growth, and reproduction of mature plants of the two species grown in a common garden field experiment. No plants died from damage after 6 yr. Black swallowwort produced more aboveground biomass, whereas pale swallowwort produced more root biomass and root crown buds, compared with its congener species. For most damage treatments, root biomass and the number of crown buds and stems increased over time, whereas aboveground biomass and viable seeds per plant generally did not change. Substantial overlap in plant size and seed production occurred among damage treatments and species. The most severe defoliation treatment did not substantially limit growth and reproduction compared with undamaged plants. While two clippings per season sometimes prevented seed production, four clippings per season was the only type of damage that consistently prevented plant growth and eliminated seed production. Pale and black swallowwort display a high tolerance to aboveground tissue loss in high-light environments without plant competition. The annual increase in plant size calls into question the potential efficacy of a defoliating insect against field populations of swallowworts, and it seems likely the only benefits of a long-term mowing regime will be to eliminate seed production.

Effective control techniques for pale swallowwort (PSW), an invasive herbaceous vine of old fields and forest understories, are limited. We conducted a 3-yr cutting and herbicide study on an adjacent old-field and forest understory site near Ithaca, NY, for control of PSW. Plants in experimental plots were cut in early July and cut again or sprayed in late August for two seasons with the isopropylamine salt of glyphosate, or one of two rates (low or high) of either triclopyr triethylamine salt (i.e., SL, SH) or triclopyr butoxyethyl ester (EL, EH). The herbicide treatments were effective in reducing PSW cover, plant (stem) density, and aboveground biomass in the old-field site, but in several cases, only after 2 yr of cutting plus herbicide application. Only the cutting plus SH treatment did not reduce PSW cover relative to the unmanaged control in the forest understory and no treatment reduced biomass. In general, the cutting plus EH treatment was most effective in reducing PSW stem densities in the forest site. The most effective herbicide treatments differed between sites. Cutting plus EH reduced PSW cover by 84% and stem density (> 5 cm) by 86% in the old-field site. Cutting plus SH effectively decreased long and short (≤ 5 cm) stem densities by 86 and 96%, respectively. Cutting plants twice during each of two seasons increased PSW cover by 301% and density of stems > 5 cm by 73% at this site. In the forest site, cutting plus glyphosate, or cutting plus EH or cutting plus SL and EL resulted in the greatest reductions in PSW cover (80, 76, 66, and 56%, respectively). Cover in plots cut twice per year decreased by 19%. The EH or SL treatments decreased long-stem densities by 78 and 71%, respectively. The EH treatment decreased short-stem density by 37%. These findings suggest that integrated techniques may control PSW but that effective management strategies may be habitat constrained.

Pale swallow-wort is a nonnative vine, invading natural areas across much of the northeastern United States and southeastern Canada. Control of this clump-forming herbaceous perennial has been difficult. We conducted a 2-yr study (2005–2006) in a heavily infested site in Chaumont, NY to assess the response of swallow-wort to triclopyr applied once as a foliar treatment (1.9 kg ae/ha) (2005 only) alone or in combination with clipping 4 wk later, followed by a single clipping in 2006. We also evaluated the response of swallow-wort to one or two clippings during each of the 2 yr. Two yr after treatments began, swallow-wort cover was lower in plots treated with triclopyr (20 ± 5%) compared with plots subjected to clipping-only (56 ± 6%) or unmanaged controls (76 ± 6%). Stem densities were also lower in triclopyr-treated plots (25 ± 5 stems/m2) than in clipping-only (188 ± 9 stems/m2) and control (178 ± 10 stems/m2) plots across three different sample dates. Seedling densities were lower in triclopyr-treated plots (160 ± 50 seedlings/m2) relative to clipping-only (1,120 ± 180 seedlings/m2) and control (960 ± 50 seedlings/m2) plots after the 2005 growing season. The cover of other plant species was negatively correlated with swallow-wort cover and was higher in triclopyr-treated plots (75 ± 3%) than in clipping-only (5 ± 1%) and control (7 ± 4%) plots in 2006. Across both years, swallow-wort in control and clipped plots produced follicles, but not in triclopyr-treated plots. Regardless of clipping frequency, clipping in June or July was not effective in reducing swallow-wort stem density, cover, or follicle production. Although a single application of triclopyr provided considerable suppression of swallow-wort after two growing seasons, application of triclopyr in subsequent years is likely required to achieve long-term control.

Theory suggests that values are important in determining an individual's behaviour and preferences related to environmental issues; however robust models that attempt to describe empirical relationships have proven elusive. This paper describes a model that clarified some relationships between values and preferences for the future management of natural areas. The key element in the model was the use of a new scale, the Natural Area Value Scale (NAVS) for measuring the relative strengths of individuals' intrinsic, non-use, use and recreation values for natural areas. Also of importance was a variable that grouped people according to their common values. The data were obtained from samples of the general public, environmentalists and farmers in Australia and were analysed in a structural equation model. The model indicated the relative importance of particular value components in determining nature conservation preferences, as well as individuals' willingness to make personal sacrifices to secure these preferences for protecting natural areas. The model fit differed for the three samples: it provided a good fit for the general public sample, for which it was designed, and weaker fit for environmentalists and farmers. The work contributes to understanding of the values that underlie conservation decisions and provides a basis for further research to develop the model's explanatory power.