Saltmarshes are widely recognized as one of the most productive coastal habitats, and on the Amazon coast, Spartina alterniflora marshes are widespread on both marine and freshwater sites. On the Amazon coast, this ecosystem is subject to a wide array of environmental factors that influence its characteristics and associated macrobenthic fauna. However, few studies have been carried out in Amazonian saltmarshes when compared to others regions worldwide. Therefore, this study characterizes the vertical distribution of macrobenthic fauna in Amazon saltmarshes and their seasonal changes. Vertical stratified samples (0–10 and 10–20 cm) were collected during the rainy (April 2008) and dry seasons (November 2008) in saltmarshes located in an Environmental Protected Area located on the Northern Brazilian Amazon coast (Algodoal-Maiandeua island). The saltmarsh area varied between seasons, being denser and taller in the dry season. A total of 38 macrobenthic taxa were recorded, of which 11 were exclusively found in the dry season. The macrobenthic faunal structure varies among seasons, with higher density and richness in the dry season. Overall, higher densities and richness were found at near-surface layers in both seasons. We suggest that the vertical distribution of the macrobenthic fauna depend on the vegetation density in Amazon saltmarshes, since this vertical distribution is more prominent in the dry season where we observed higher Spartina density and most of the fauna is concentrated near the surface. Therefore, this study provides novel insights into macrobenthic distribution patterns, reinforcing that Amazonian saltmarshes have unique characteristics that strongly influence their distribution.

Basal bark application involves applying an oil-soluble herbicide in an oil carrier to the lower 0 to 45 cm of woody stems. For triclopyr, basal bark application typically requires the butoxyethyl ester formulation; however, this cannot be applied when standing water is present, which is common in seasonally flooded wetlands. Recently, the intermediate oil and water-soluble triclopyr acid formulation was registered for use in aquatic sites, allowing for basal bark applications in wetlands where standing water is present. Recent studies indicated that flooding after basal bark treatment can result in triclopyr release to surface waters and subsequent non-target injury. Elevated band application height (i.e., treating a higher band on each stem) may reduce non-target injury potential; however, this modified application technique has not been well tested on woody invasive species. To evaluate this approach, a field study on Brazilian peppertree (Schinus terebinthifolia Raddi) was conducted near Melbourne and Wimauma, FL, on well-established and juvenile rootstocks. Treatments included triclopyr acid at 17, 34, and 69 g L−1 applied in an oil carrier and treatment band heights of 0 to 45 cm and 61 to 107 cm from the groundline. At Melbourne, both band heights treated with 34 or 69 g L−1 resulted in 75% to 100% mortality of mature rootstocks. However, triclopyr applied at 17 g L−1 to the low and elevated band heights resulted in 70% and 11% mortality, respectively. All treatments resulted in 90% to 100% mortality at Wimauma, where the rootstocks were juvenile and much smaller. These findings indicate elevated band heights may be a useful approach for woody plant control and may support an effective management strategy in inundated wetlands that provides better prevention of non-target injury.

Highly pathogenic avian influenza (HPAI) outbreaks have repeatedly occurred in two districts of Kerala state, India, over the last few years. The outbreaks in the wetland areas coincided with the arrival of migratory birds. At the time, the factors responsible for local transmission in ducks were not known. This study aimed to identify the socio-economic factors responsible for spatial variation in the occurrence of HPAI outbreaks in the two districts using Bayesian network modelling (BNM) and Stochastic Partial Differential Equation (SPDE) model. Further, information was collected on the duck rearing practices in rice paddy fields to identify the risk factors for local – spread of the outbreaks. We found that the SPDE model without covariates explained variation in occurrence of outbreaks. The number of rice paddy fields used by the duck farmers was identified as risk factor. We concluded based on BNM and SPDE that the infected migratory birds were the source of infection for the first few duck farms in the wetland areas and subsequent transmission was driven by shifting of ducks from one rice paddy field to other fields. There is a probability of persistent and recurrent infections in the ducks and possible spill over to humans. Hence, it is important to have surveillance in ducks to prevent recurrent outbreaks in the region.

There are six species of flamingos in the world, all under pressure from human activities in their wetland habitats. Obtaining global population estimates for flamingos is challenging because of their broad geographical range, nomadic movements, capacity for long-distance flight, and the complexity of international monitoring. Two species, the Andean Flamingo Phoenicoparrus andinus and Puna Flamingo P. jamesi, during key parts of their life cycle, use wetlands in the Andes of South America, where they coexist at various sites. We compiled historical information on population estimates and ecology for these two species and integrated data collected on regional simultaneous censuses to describe population trends, current and emerging threats, and provide recommendations for conservation action. Long-term population trends have been difficult to establish given the unreliability of population estimates prior to the late 1990s. Systematic, regional censuses carried out regularly since 1997 have produced robust population estimates for the Andean and Puna flamingos (most recently, 78,000 and 154,000, respectively) and show populations of both species to be stable and increasing. Increasingly rapid changes in wetlands caused by human activities such as industrial-scale mining in breeding and foraging sites in the high Andes wetlands, and agro-industrial activities in their lowland wintering sites, focused on areas of the highest concentrations of flamingos pose threats to their survival and ability to reproduce. In addition, climate change is projected to reduce wetland habitats and some localised effects have already been detected. Continued research on the ecological drivers of flamingo abundance, movements, and population genetics to understand population structure and dynamics are necessary, as well as the identification of response variables to changing environmental conditions. Interdisciplinary and systems-level approaches in the context of international collaboration in monitoring and conservation planning among a diversity of stakeholders will be required to safeguard flamingo populations and wetland habitats.

Flowering rush (Butomus umbellatus L.) is an emergent perennial monocot that has invaded aquatic systems along the U.S.–Canadian border. Currently, there are two known cytotypes of flowering rush, diploid and triploid, within the invaded range. Although most studies have focused on the triploid cytotype, little information is known about diploid plants. Therefore, phenology and resource allocation were studied on the diploid cytotype of flowering rush in three study sites (Mentor Marsh, OH; Tonawanda Wildlife Management Area, NY; and Unity Island, NY) to understand seasonal resource allocation and environmental influences on growth, and to optimize management strategies. Samples were harvested once a month from May to November at each site from 2021 to 2023. Plant metrics were regressed to air temperature, water temperature, and water depth. Aboveground biomass peaked from July to September and comprised 50% to 70% of total biomass. Rhizome biomass peaked from September to November and comprised 40% to 50% of total biomass. Rhizome bulbil densities peaked from September to November at 3,000 to 16,000 rhizome bulbils m−2. Regression analysis resulted in strong negative relationships between rhizome starch content and air temperature (r2 = 0.52) and water temperature (r2 = 46). Other significant, though weak, relationships were found, including a positive relationship between aboveground biomass and air temperature (r2 = 0.17), a negative relationship between rhizome bulbil biomass and air temperature (r2 = 0.18) and a positive relationship between leaf density and air temperature (r2 = 0.17). Rhizomes and rhizome bulbils combined stored up to 60% of total starch, and therefore, present a unique challenge to management, as these structures cannot be reached directly with herbicides. Therefore, management should target the aboveground tissue before peak production (July) to reduce internal starch storage and aim to limit regrowth over several years.

This paper hypothesizes that respondents in contingent valuation surveys may form different benefit and cost levels that deviate from the levels specified by the researcher. The conceptual framework investigates potential biases based on the direction of deviations. Survey data on the restoration of wetlands in Tampa Bay show that a significant portion of the respondents deviate from the benefit and cost levels presented in the scenario. Empirical results indicate that willingness-to-pay (WTP) estimates are very sensitive to the perceived benefit and cost levels. Depending on the direction of the deviations, WTP estimates could fluctuate up to +61 percent and −82 percent, compared to the estimate from those who evaluate the scenario at the presented levels.

Nymphaea thermarum Eb. Fisch. (family Nymphaeaceae) is a small waterlily endemic to Rwanda that has been categorized as Extinct in the Wild since 2010. We report the rediscovery of N. thermarum in July 2023, not far from its locus classicus, identify the current and potential threats to the wild population (mining and overharvesting by collectors, respectively) and recommend the urgent conservation measures and research required to save the species from extinction. The species occupies small muddy ditches fed by hot spring water used for avocado plantations and fish pools. The population comprises hundreds of individuals, including reproductive adult plants, and seedlings. In the short term, conservation actions should include land protection, negotiation to ensure that sufficient water is reaching the habitat of N. thermarum and the reassessment of the species on the IUCN Red List, probably as Critically Endangered. In the medium term, the creation of a nature reserve, the restoration of the areas already affected by mining, and the reintroduction of N. thermarum to its original site would support long-term in situ conservation of the species. Further research should clarify the total and effective population size, population structure, ecology and genetics of this species.

Basal bark treatment with triclopyr butoxyethyl ester is used to control woody invasive plants, including Brazilian peppertree (Schinus terebinthifolia Raddi). However, the ester formulation cannot be applied where standing water is present, which includes wetlands where S. terebinthifolia is found. In 2009, a low-volatile acid formulation of triclopyr was labeled for use in aquatic sites, which allows for basal bark applications when standing water is present. This formulation may have utility for controlling woody plants in standing water. However, anecdotal observations of injury to non-target plants following applications during periods of inundation have been reported. To address this, mesocosm studies were conducted to assess non-target injury through triclopyr root exudation or release from the surface of treated stems via flooding. Mesocosms contained S. terebinthifolia as the treated target, while sugarberry (Celtis laevigata Willd.), buttonbush (Cephalanthus occidentalis L.), and red maple (Acer rubrum L.) were included as non-targets. In the first study, the pathway of root exudation for non-target injury following triclopyr (34 g L−1) basal bark application was isolated with activated charcoal placed at the soil surface. In the second study, mesocosms were flooded to assess triclopyr release from the surface of treated stems and subsequent non-target injury. Defoliation of non-target species posttreatment was ≤8%, and triclopyr was detected at ≤5 µg L−1 in mesocosm wells when activated charcoal was present. Posttreatment non-target defoliation up to 92%, coupled with triclopyr concentrations in surface waters and wells as high as 4,637 µg L−1, indicated triclopyr movement as a result of flooding. Additionally, triclopyr non-target injury from soil activity independent of flooding was observed. These findings provide limited evidence of triclopyr root exudation but considerable evidence of triclopyr release during flooding following basal bark treatment and support a cautionary approach to basal bark application when standing water is present.

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.