Ecological dispersal mechanisms, reproductive ecology, and the importance of scale in Zostera marina in Chesapeake Bay

Previous knowledge of the seed ecology of the clonal seagrass Zostera marina L. (eelgrass) suggests that sexual reproduction is not very important to the population dynamics of eelgrass; however, researchers have hypothesized long-distance dispersal for nearly a century. From a bay-wide sampling effort, viable eelgrass seeds in the seed bank were found throughout most of the lower and middle Chesapeake Bay, but abundance of seeds was highly variable. Lower seed-bank densities were found in middle Chesapeake Bay, the region with slow recovery of eelgrass populations. From natural and artificially created eelgrass populations, regional environmental conditions were found to have a greater impact on reproductive shoot (reproductive effort) and seed (reproductive output) production than small-scale influences of location and patch structure. Detached reproductive shoots of eelgrass (containing viable seeds) held in greenhouse tanks remained buoyant for several weeks before they degraded, sank, and lost all their seeds. In offshore shoal areas, suitable for eelgrass growth and survival, seventy percent of tube caps of the polychaete Diopatra cuprea (found throughout the shallow regions of Chesapeake Bay) had fragmented reproductive shoots built into its walls, suggesting a mechanism for seeding these shallow areas. Viable eelgrass seeds were found throughout the shoreline of south Chesapeake Bay, up to 34 km away from the nearest bed. Additionally, a GIS exercise identified new eelgrass patches up to 108 km from the nearest source population. The use of burlap bags for protecting seeds from predation, burial, or lateral transport maximized germination success over unprotected seeds in the field and provides a new mechanism for restoration efforts. An ecological model of eelgrass reproduction highlighted the potentially significant contribution of seeds to the long-term productivity of eelgrass at different water depths. Exploring theoretical scenarios, the model can be used to predict the total number of seeds produced for one to germinate and successfully establish as a seedling, as well as determine the size of patches, newly created from seeds, based on the number of viable seeds in the seed bank and the vigor of the seedlings that develop

Enhancing multiple benefits of brownfield cleanups by applying ecosystem services concepts

Brownfields are increasingly called upon to be transformed from potentially contaminated, often vacant properties into community assets that provide multiple benefits. Further, brownfields revitalization can provide critical opportunities and, particularly, nature-based solutions can enhance multiple ecological, human health, and economic benefits. Through a series of non-exhaustive surveys of existing examples of environmental benefits of cleanups, case study examples of brownfield cleanups achieving environmental benefits, and potential ecosystem services tools relevant to steps of a brownfields cleanup effort, we explore practical ideas for enhancing environmental benefits of brownfields cleanups by applying ecosystem services concepts. Examples of nature-based solutions, where appropriate, include the use of rain gardens, permeable pavements, green spaces, and the use of green technologies. Further, this article provides an overview of recent policy initiatives focused on nature-based solutions and enhancing ecosystem services in brownfields cleanup, revitalization, and reuse. Our goals are to increase the knowledge base on these opportunities and discuss how these concepts can be achieved through sharing success stories, making outreach materials accessible, and holding workshops to help successfully operationalize these concepts in a community’s visioning for upcoming revitalization projects

Informatics and data mining tools and strategies for the Human Connectome Project

The Human Connectome Project (HCP) is a major endeavor that will acquire and analyze connectivity data plus other neuroimaging, behavioral, and genetic data from 1,200 healthy adults. It will serve as a key resource for the neuroscience research community, enabling discoveries of how the brain is wired and how it functions in different individuals. To fulfill its potential, the HCP consortium is developing an informatics platform that will handle: 1) storage of primary and processed data, 2) systematic processing and analysis of the data, 3) open access data sharing, and 4) mining and exploration of the data. This informatics platform will include two primary components. ConnectomeDB will provide database services for storing and distributing the data, as well as data analysis pipelines. Connectome Workbench will provide visualization and exploration capabilities. The platform will be based on standard data formats and provide an open set of application programming interfaces (APIs) that will facilitate broad utilization of the data and integration of HCP services into a variety of external applications. Primary and processed data generated by the HCP will be openly shared with the scientific community, and the informatics platform will be available under an open source license. This paper describes the HCP informatics platform as currently envisioned and places it into the context of the overall HCP vision and agenda

Applying cumulative effects to strategically advance large-scale ecosystem restoration

International efforts to restore degraded ecosystems will continue to expand over the coming decades, yet the factors contributing to the effectiveness of long-term restoration across large areas remain largely unexplored. At large scales, outcomes are more complex and synergistic than the additive impacts of individual restoration projects. Here, we propose a cumulative-effects conceptual framework to inform restoration design and implementation and to comprehensively measure ecological outcomes. To evaluate and illustrate this approach, we reviewed long-term restoration in several large coastal and riverine areas across the US: the greater Florida Everglades; Gulf of Mexico coast; lower Columbia River and estuary; Puget Sound; San Francisco Bay and Sacramento–San Joaquin Delta; Missouri River; and northeastern coastal states. Evidence supported eight modes of cumulative effects of interacting restoration projects, which improved outcomes for species and ecosystems at landscape and regional scales. We conclude that cumulative effects, usually measured for ecosystem degradation, are also measurable for ecosystem restoration. The consideration of evidence-based cumulative effects will help managers of large-scale restoration capitalize on positive feedback and reduce countervailing effects

Hurricane Effects on a Shallow Lake Ecosystem and Its Response to a Controlled Manipulation of Water Level

In order to reverse the damage to aquatic plant communities caused by multiple years of high water levels in Lake Okeechobee, Florida (U.S.), the Governing Board of the South Florida Water Management District (SFWMD) authorized a "managed recession" to substantially lower the surface elevation of the lake in spring 2000. The operation was intended to achieve lower water levels for at least 8 weeks during the summer growing season, and was predicted to result in a large-scale recovery of submerged vascular plants. We treated this operation as a whole ecosystem experiment, and assessed ecological responses using data from an existing network of water quality and submerged plant monitoring sites. As a result of large-scale discharges of water from the lake, coupled with losses to evaporation and to water supply deliveries to agriculture and other regional users, the lake surface elevation receded by approximately 1 m between April and June. Water depths in shoreline areas that historically supported submerged plant communities declined from near 1.5 m to below 0.5 m. Low water levels persisted for the entire summer. Despite shallow depths, the initial response (in June 2000) of submerged plants was very limited and water remained highly turbid (due at first to abiotic seston and later to phytoplankton blooms). Turbidity decreased in July and the biomass of plants increased. However, submerged plant biomass did not exceed levels observed during summer 1999 (when water depths were greater) until August. Furthermore, a vascular plant-dominated assemblage (Vallisnera, Potamogeton, and Hydrilla) that occurred in 1999 was replaced with a community of nearly 98% Chara spp. (a macro-alga) in 2000. Hence, the lake’s submerged plant community appeared to revert to an earlier successional stage despite what appeared to be better conditions for growth. To explain this unexpected response, we evaluated the impacts that Hurricane Irene may have had on the lake in the previous autumn. In mid-October 1999, this category 1 hurricane passed just to the south of the lake, with wind velocities over the lake surface reaching 90 km h-1 at their peak. Output from a three-dimensional hydrodynamic / sediment transport model indicates that during the storm, current velocities in surface waters of the lake increased from near 5 cm s-1 to as high as 100 cm s-1. These strong velocities were associated with large-scale uplifting and horizontal transport of fine-grained sediments from the lake bottom. Water quality data collected after the storm confirmed that the hurricane resulted in lake-wide nutrient and suspended solids concentrations far in excess of those previously documented for a 10-year data set. These conditions persisted through the winter months and may have negatively impacted plants that remained in the lake at the end of the 1999 growing season. The results demonstrate that in shallow lakes, unpredictable external forces, such as hurricanes, can play a major role in ecosystem dynamics. In regions where these events are common (e.g., the tropics and subtropics), consideration should be given to how they might affect long-term lake management programs

Molecularly defined circuitry reveals input-output segregation in deep layers of the medial entorhinal cortex

SummaryDeep layers of the medial entorhinal cortex are considered to relay signals from the hippocampus to other brain structures, but pathways for routing of signals to and from the deep layers are not well established. Delineating these pathways is important for a circuit level understanding of spatial cognition and memory. We find that neurons in layers 5a and 5b have distinct molecular identities, defined by the transcription factors Etv1 and Ctip2, and divergent targets, with extensive intratelencephalic projections originating in layer 5a, but not 5b. This segregation of outputs is mirrored by the organization of glutamatergic input from stellate cells in layer 2 and from the hippocampus, with both preferentially targeting layer 5b over 5a. Our results suggest a molecular and anatomical organization of input-output computations in deep layers of the MEC, reveal precise translaminar microcircuitry, and identify molecularly defined pathways for spatial signals to influence computation in deep layers

Interannual climate variation, land type and village livelihood effects on fires in Kalimantan, Indonesia

The increasing extent and frequency of fires globally requires nuanced understanding of the drivers of largescale events for improved prevention and mitigation. Yet, the drivers of fires are often poorly understood by various stakeholders in spatially expansive and temporally dynamic landscapes. Further, perceptions about the main cause of fires vary amongst stakeholders, which amplify ongoing challenges from policies being implemented inconsistently across different governance levels. Here, we develop a spatially and temporallyexplicit typology of fire prevalence across Kalimantan, Indonesia, a region with significant contribution to global greenhouse gas emissions. Based on livelihood information and data on climate, soil type and forest degradation status, we find that in intact forest the density of fires in villages that largely coincide with oil palm concessions was twice as high as in villages outside the concessions across all years. Fires occurring in degraded land on mineral soil across all years were also most prevalent in villages with industrial plantations (oil palm or timber). On the other hand, in degraded peatland, where fires are most intense during dry years induced by the El Niño episodes, occurrence rates were high regardless of village primary livelihoods. Based on these findings we recommend two key priorities for fire mitigation going forward for policy across different governance levels in Kalimantan: degraded peatland as the priority area and industrial plantations as the priority sector. Our study suggests a fire prevention and mitigation approach, which accounts for climate, land type and village livelihood, has the potential to deliver more effective means of management

Synthesis of Two Decades of US EPA’s Ecosystem Services Research to Inform Environmental, Community and Sustainability Decision Making

A conceptual framework is helpful to understand what types of ecosystem services (ES) information is needed to support decision making. Principles of structured decision making are helpful for articulating how ES consideration can influence different elements in a given decision context resulting in changes to the environment, human health, and well-being. This article presents a holistic view of an ES framework, summarizing two decades of the US EPA’s ES research, including recent advances in final ES, those ES that provide benefits directly to people. Approximately 150 peer-reviewed publications, technical reports, and book chapters characterize a large ES research portfolio. In introducing framework elements and the suite of relevant US EPA research for each element, both challenges and opportunities are identified. Lessons from research to advance each of the final ES elements can be useful for identifying gaps and future science needs. Ultimately, the goal of this article is to help the reader develop an operational understanding of the final ES conceptual framework, an understanding of the state of science for a number of ES elements, and an introduction to some ES tools, models, and frameworks that may be of use in their case-study applications or decision-making contexts

Connecting Future Environmental Trends and Assessments of Fish and Wildlife Resources of Concern: A Case Study of Big Pine Key, Florida

Changes in hydrologic and climatic trends will influence the ecology of Florida, and climate scenarios agree that many areas of Florida are susceptible to sea-level rise impacts. The U.S. Fish and Wildlife Service’s Climate Change Action Program focuses on a framework to examine climate change effects on fish, wildlife, plants, and habitats of all three. To follow the program, this study examines how to incorporate current scientific knowledge about regional climate projections in U.S. Fish and Wildlife Service analyses. It provides climate change and sea-level rise projections based on 2017 projections, information on changes in tropical cyclones, temperatures, and precipitation. This study also examines future effects of sea-level rise on existing habitat from saltwater intrusion of the freshwater lens below Big Pine Key. Projections of future sea-water elevations will periodically be reached or exceeded well before 2040 from short-term, stochastic, and extreme events (e.g., king tides and storm surge), and will increasingly inundate the root zone before complete saltwater intrusion. Future trends were connected to 2017 stakeholder-driven conversations about adaptation strategies to develop a suite of actions for creating temporary or permanent freshwater resources. However, beyond 3 ft (0.9 m) of sea-level rise, there are few adaptation options available for the Florida Key deer beyond relocations outside of the Florida Keys. Overall, the approach of connecting future environmental trends to assessments of fish and wildlife resources of concern can be transferred to other situations. Additionally, this approach can be used to update these analyses, such as with the recent 2022 sea-level rise updates by the National Oceanic and Atmospheric Administration, released after this work was conducted

Metabolically active bacteria detected with click chemistry in low organic matter rainwater.

Rain contains encapsulated bacteria that can be transported over vast distances during relatively short periods of time. However, the ecological significance of bacteria in "precontact" rainwater-rainwater prior to contact with non-atmospheric surfaces-remains relatively undefined given the methodological challenges of studying low-abundance microbes in a natural assemblage. Here, we implement single-cell "click" chemistry in a novel application to detect the protein synthesis of bacteria in precontact rainwater samples as a measure of metabolic activity. Using epifluorescence microscopy, we find approximately 103-104 bacteria cells mL-1 with up to 7.2% of the observed cells actively synthesizing protein. Additionally, our measurement of less than 30 μM total organic carbon in the samples show that some rainwater bacteria can metabolize substrates in very low organic matter conditions, comparable to extremophiles in the deep ocean. Overall, our results raise new questions for the field of rainwater microbiology and may help inform efforts to develop quantitative microbial risk assessments for the appropriate use of harvested rainwater