Explore the vast range of titles available.

Peatland environments provide important ecosystem services including water and carbon storage, nutrient processing and retention, and wildlife habitat. However, these systems and the services they provide have been degraded through historical anthropogenic agricultural conversion and dewatering practices. Effective wetland restoration requires incorporating site hydrology and understanding groundwater discharge spatial patterns. Groundwater discharge maintains wetland ecosystems by providing relatively stable hydrologic conditions, nutrient inputs, and thermal buffering important for ecological structure and function; however, a comprehensive site-specific evaluation is rarely feasible for such resource-constrained projects. An improved process-based understanding of groundwater discharge in peatlands may help guide ecological restoration design without the need for invasive methodologies and detailed site-specific investigation. Here we examine a kettle-hole peatland in southeast Massachusetts historically modified for commercial cranberry farming. During the time of our investigation, a large process-based ecological restoration project was in the assessment and design phases. To gain insight into the drivers of site hydrology, we evaluated the spatial patterning of groundwater discharge and the subsurface structure of the peatland complex using heat-tracing methods and ground-penetrating radar. Our results illustrate that two groundwater discharge processes contribute to the peatland hydrologic system: diffuse lower-flux marginal matrix seepage and discrete higher-flux preferential-flow-path seepage. Both types of groundwater discharge develop through interactions with subsurface peatland basin structure, often where the basin slope is at a high angle to the regional groundwater gradient. These field observations indicate strong correlation between subsurface structures and surficial groundwater discharge. Understanding these general patterns may allow resource managers to more efficiently predict and locate groundwater seepage, confirm these using remote sensing technologies, and incorporate this information into restoration design for these critical ecosystems.

Large-scale wetland restoration often focuses on repairing the hydrologic connections degraded by anthropogenic modifications. Of these hydrologic connections, groundwater discharge is an important target, as these surface water ecosystem control points are important for thermal stability, among other ecosystem services. However, evaluating the effectiveness of the restoration activities on establishing groundwater discharge connection is often difficult over large areas and inaccessible terrain. Unoccupied aircraft systems (UAS) are now routinely used for collecting aerial imagery and creating digital surface models (DSM). Lightweight thermal infrared (TIR) sensors provide another payload option for generation of sub-meter-resolution aerial TIR orthophotos. This technology allows for the rapid and safe survey of groundwater discharge areas. Aerial TIR water-surface data were collected in March 2019 at Tidmarsh Farms, a former commercial cranberry peatland located in coastal Massachusetts, USA (41°54′17″ N 70°34′17″ W), where stream and wetland restoration actions were completed in 2016. Here, we present a 0.4 km2 georeferenced, temperature-calibrated TIR orthophoto of the area. The image represents a mosaic of nearly 900 TIR images captured by UAS in a single morning with a total flight time of 36 min and is supported by a DSM derived from UAS-visible imagery. The survey was conducted in winter to maximize temperature contrast between relatively warm groundwater and colder ambient surface environment; lower-density groundwater rises above cool surface waters and thus can be imaged by a UAS. The resulting TIR orthomosaic shows fine detail of seepage distribution and downstream influence along the several restored channel forms, which was an objective of the ecological restoration design. The restored stream channel has increased connectivity to peatland groundwater discharge, reducing the ecosystem thermal stressors. Such aerial techniques can be used to guide ecological restoration design and assess post-restoration outcomes, especially in settings where ecosystem structure and function is governed by groundwater and surface water interaction.

Large-scale wetland restoration often focuses on repairing the hydrologic connections degraded by anthropogenic modifications. Of these hydrologic connections, groundwater discharge is an important target, as these surface water ecosystem control points are important for thermal stability, among other ecosystem services. However, evaluating the effectiveness of the restoration activities on establishing groundwater discharge connection is often difficult over large areas and inaccessible terrain. Unoccupied aircraft systems (UAS) are now routinely used for collecting aerial imagery and creating digital surface models (DSM). Lightweight thermal infrared (TIR) sensors provide another payload option for generation of sub-meter-resolution aerial TIR orthophotos. This technology allows for the rapid and safe survey of groundwater discharge areas. Aerial TIR water-surface data were collected in March 2019 at Tidmarsh Farms, a former commercial cranberry peatland located in coastal Massachusetts, USA (41°54'17\" N 70°34'17\" W), where stream and wetland restoration actions were completed in 2016. Here, we present a 0.4 km2 georeferenced, temperature-calibrated TIR orthophoto of the area. The image represents a mosaic of nearly 900 TIR images captured by UAS in a single morning with a total flight time of 36 min and is supported by a DSM derived from UAS-visible imagery. The survey was conducted in winter to maximize temperature contrast between relatively warm groundwater and colder ambient surface environment; lower-density groundwater rises above cool surface waters and thus can be imaged by a UAS. The resulting TIR orthomosaic shows fine detail of seepage distribution and downstream influence along the several restored channel forms, which was an objective of the ecological restoration design. The restored stream channel has increased connectivity to peatland groundwater discharge, reducing the ecosystem thermal stressors. Such aerial techniques can be used to guide ecological restoration design and assess post-restoration outcomes, especially in settings where ecosystem structure and function is governed by groundwater and surface water interaction.

Aims To improve soil phosphorus (P) testing in silvicultural systems, we assess microdialysis to study concentrations and establish a standard methodology to assess soil diffusive P and in-vivo translocated sap flow P under variable rates of P carryover from a previous rotation across various soils. Methods Soils were collected from each treatment in the field and analyzed in laboratory conditions. Soils were analyzed for diffusive soil P using microdialysis and Mehlich III for comparison. Sap flow P measurements were collected in the field from 16 trees, one tree per treatment and replication over four hours. Results Spodosol soils had higher diffusive P levels than Alfisol soils. On average, diffusive P increased by 137% in Spodosol and 166% in Alfisol from pre- to post-planting of a new stand. In the Alfisol, diffusive P showed a strong relationship with tree height, while no significant association was observed in the Spodosol. The Mehlich III soil extractions were positively related to the Alfisol but not the Spodosol. Microdialysis samples collected from the trees responded to changes in fertilization rates and were shown to be positively related to tree heights and Mehlich soil P tests. Atmospheric conditions substantially impacted sap flow P, with samples collected in full sunlight showing an average increase of 100% compared to overcast conditions. Conclusions These findings demonstrate the potential of microdialysis as a valuable tool for soil P testing and its application in addressing complex questions related to P translocation and tree physiology in silvicultural settings.

Methane (CH4) is a major and potent greenhouse gas (GHG), and its emissions from agricultural activities, particularly rice cultivation, are a significant concern for climate change. Due to the high demand for food security, driven by rapid population growth and national initiatives to reduce dependency on rice imports, rice cultivation is intensified in West Africa. However, its contribution to atmospheric CH4 remains largely unknown. Here, for the first time, cutting-edge eddy covariance tower measurements were conducted parallelly in a rice field (Janga) and a reserve forest (Mole National Park), both located in the Guinea savanna region of West Africa. Using CH4 measurement data from June to October 2023 (rice cultivation period), the dynamic interplay between methane emissions from rice cultivation and its potential mitigation through forest methane uptake was assessed. Our results show that the rice field acted as a net source of CH4 at a rate of 2037 mgCH4m−2, whereas the most intense flooded period (August) accounted for 70% of the total emissions. On the other hand, the forest reserve acted as a sink, with a net uptake of −560 mgCH4m−2, and the highest uptake observed in October. Accounting for the global warming potential (GWP) of CH4 over a 20 year period, the forest had a wet season negative GWP of −47.04 gCO2eq, while the rice field emitted CH4 of 171.36 gCO2eq. This implies that under similar conditions during the measurement campaigns, the forest per square area needs approximately a factor of ∼4 to balance the positive radiative effect per square area of rice cultivated. This work emphasizes the need to integrate forests to compensate for methane released by rice cultivation in the semi-arid West African savannah region.

Synthetic hydroxyapatite (HA) was compared against triple superphosphate (TSP) and two unprocessed phosphate rocks (PR1, PR2) to (1) quantify and assess a synthetic lamellar structured-HA for its solubility and diffusiveness under acidic, sandy, soil conditions, (2) Evaluate synthetic lamellar structured-HA as a phosphorus early rotation fertilizer for Eucalyptus saplings. Soil incubation experiments verified that HA released more diffusive phosphorus into the soil than non-synthetic phosphate rock and had similar amounts of diffusive phosphorus as TSP. The solubility of HA at pH 3 and pH 6 was higher than that of raw ground phosphate rocks (apatites). Total dry-matter yield (DMY) and shoot-length of Eucalyptus seedlings grown for 154 days in acid soil (pH 4.9) were increased significantly by the application of HA compared to the control, PR2, and mixed (HA + PR2). The lack of a DMY response using TSP indicates that phosphorus may not have been the limiting factor. However, considering TSP and HA had similar solubilities and released diffusive phosphorus at similar levels, the only variable we failed to control for was the CaCO 3 provided by the HA and not the TSP. Further experimentation is needed to confirm this hypothesis. Overall, HA is a promising candidate to supplement traditional phosphorus fertilizers for acidic sandy Eucalyptus silviculture.