Reed canarygrass (Phalaris arundinacea) is invasive in temperate freshwater wetlands throughout the United States and Canada and presents challenges to restoring tidal freshwater wetlands. Methods for the prevention or elimination of reed canarygrass in palustrine wetlands are generally well established, typically involving herbicide application, mechanical treatments, prolonged inundation, or establishment of competitive plant species. These methods are often not suitable for the unique conditions in tidal wetlands and alternative strategies remain poorly understood. Prolonging inundation of tidal wetlands requires a loss of habitat forming processes, connectivity, and other functions. Treatments such as mowing, discing, or fire are not feasible in the perpetually wet conditions of tidal wetlands. Restoration practitioners aiming to design self-sustaining wetlands in the lower Columbia River estuary and the U.S. Pacific Coast have found that reed canarygrass is widespread and quick to establish post-restoration creating a management burden and impacting restoration goals. Here we report the results of a comprehensive effort to develop methods for control in tidal wetlands through systematic review of the scientific literature, interviews with experienced practitioners, and field observations at nine Pacific Northwest sites. The review framework evaluated key environmental conditions affecting reed canarygrass, control methods, and practical considerations. Findings support an integrated long-term control strategy at the largest possible scale to establish effective and self-sustaining control. Appropriate and practical strategies for tidal freshwater wetlands include implementing control pre-restoration to suppress existing populations; topographic modification such as scrape-downs and mounds to support competitiveness of desired vegetation communities; seeding or planting strong native competitors; limiting nutrient availability; and periodic, targeted control to limit reinvasion. These strategies are supported by the study, but long-term results are generally not available. Formal field experiments are recommended by the authors to better evaluate factors that influence reed canarygrass control in tidal freshwater wetlands.

Invasive shrubs are flourishing in temperate, deciduous forest understories of eastern North America where resources, especially light, are limited. However, understory light is more available before the overstory canopy leaves emerge in the spring and after fall senescence. Extended leaf phenology of invasive shrubs in the spring and fall compared to native shrubs and the overstory canopy is conspicuous, as well as higher foliage abundance of invasive compared to native shrubs. Extended leaf phenology of invasive shrubs provides photosynthetic benefits, but also seasonally novel shade. Light and temperature regulate life history characteristics across taxa and influence ecosystem processes. Here, a long-term invasive shrub removal experiment is used to quantify the effect on light and air temperature over 3–4 y. There was a pattern of reduced maximum air temperature in the presence of invasive shrubs during the growing season of most years. We find less light energy infiltration (lumens m^–2) below invasive shrubs than native shrubs with mean differences largest in the spring (–1981 [–2604, –1380], a 26.8% reduction relative to below natives). Differences diminish through summer (–1038 [–1221, –845]), fall (–547 [–660, –429]), and winter (–257 [–372, –151]). Invasive shrubs also filter more photosynthetically active radiation than natives (58.4 [38.5, 78.7] µmol m^–2 s^–1, a 39.4% reduction), but seasonal differences were not detected indicating denser canopy structure for invasive shrubs throughout the year. When compared to the native understory community, the presence of invasive shrubs seasonally reduces temperature and light availability near the forest floor, which could affect resident plant and animal species.

The effects of climate change on plant communities are already observable in many regions. In the tallgrass region of the Northern Great Plains, plant community composition may have shifted in response to increases in both annual precipitation and temperature. We compared community composition of a tallgrass prairie among three sampling periods (1978–1979, 1998, and 2014), spanning more than three decades, in order to better understand (1) temporal shifts in plant cover and (2) which environmental variables were correlated with these changes. Basal cover of Poa pratensis increased and basal cover of forbs declined over time. The shift from a forb-rich to grass-dominated prairie was positively correlated with higher levels of precipitation and soil moisture. Our study suggests that increased precipitation due to climate change has already altered plant community composition in the Great Plains.

Here we present a framework for creating targeted invasive species mapping projects for volunteers, using simple gamification techniques to encourage participation. In Pennsylvania and New York, we chose to focus on water chestnut (Trapa natans) because this species is easy to identify, and it is often feasible to eliminate small populations from newly infested waterbodies. We established a “friendly competition” in which participants would search for water chestnut and report their findings during a specified date range. Online trainings were offered on species identification and submitting data to iMapInvasives, a mobile and browser-based mapping system. During the challenge period, volunteers were kept engaged through up-to-date data tallies and email communication from mapping challenge administrators. At the end, participants with the greatest number of data entries or most locations searched, whether submitting presence or absence information, were announced as winners and received small prizes. The data were shared with regional invasive species managers through email alerts and a summary report. Challenge participants detected water chestnut in new waterbodies and contributed valuable absence data. Over the course of three years in New York (2016–2018), participants discovered 23 new water chestnut infestation locations in 14 waterbodies. In Pennsylvania, over the course of two years (2017–2018), 44 new water chestnut infestation locations in 12 waterbodies were identified. The programs in both states have continued to build on and improve these challenge events by adding additional target species and piloting new ways to keep participants engaged through real-time dashboards and other technologies.

Lotus eremiticus is an endemic species from La Palma World Biosphere Reserve. It has a small distribution range, low population size, and is threatened by introduced herbivores. Since these threats have not been removed from the protected area, they were excluded by building a fence. The land where the species grows is private property, so an agreement with the landowner was reached to permit measures to favor its recovery. During 2008–2019, as a result of this agreement and the conservation efforts, a large population increase occurred, from the initial 5 individuals to the 30 plants that are currently distributed at the original site. Furthermore, these measures allow the species to maintain stable population dynamics, meaning that this endangered species is itself capable of recovery if the threat is removed. This is a good example of how land stewardship is an effective tool to conserve endangered species.

Coryphantha scheeri var. robustispina (Pima pineapple cactus [PPC]; Cactaceae) is a small cylindrical cactus found in semi-desert grassland and Sonoran desert-scrub in southern Arizona and northern Mexico. This species was listed as endangered in 1993 in the USA, but does not have protection in Mexico. In 2017, surveys were repeated at six PPC sites with a long monitoring history within the Altar Valley, Pima County, Arizona. Overall, PPC individuals were found at five of the six sites (i.e., 83%). Although PPC is persisting at most sites and recruitment was observed at some sites, the overall pattern was one of decline within the surveyed area. In addition, population viability analyses predict that four sites will lose more than half of their individuals within 20 y, and five sites within 50 y. The information presented in this study should be useful for making decisions regarding federal protection for Coryphantha scheeri var. robustispina.