Castaneda-Moya E.,Louisiana State University |
Twilley R.R.,Louisiana State University |
Rivera-Monroy V.H.,Louisiana State University |
Marx B.D.,Louisiana State University |
And 2 more authors.
Ecosystems | Year: 2011
Patterns of mangrove vegetation in two distinct basins of Florida Coastal Everglades (FCE), Shark River estuary and Taylor River Slough, represent unique opportunities to test hypotheses that root dynamics respond to gradients of resources, regulators, and hydroperiod. We propose that soil total phosphorus (P) gradients in these two coastal basins of FCE cause specific patterns in belowground biomass allocation and net primary productivity that facilitate nutrient acquisition, but also minimize stress from regulators and hydroperiod in flooded soil conditions. Shark River basin has higher P and tidal hydrology with riverine mangroves, in contrast to scrub mangroves of Taylor basin with more permanent flooding and lower P across the coastal landscape. Belowground biomass (0-90 cm) of mangrove sites in Shark River and Taylor River basins ranged from 2317 to 4673 g m-2, with the highest contribution (62-85%) of roots in the shallow root zone (0-45 cm) compared to the deeper root zone (45-90 cm). Total root productivity did not vary significantly among sites and ranged from 407 to 643 g m-2 y-1. Root production in the shallow root zone accounted for 57-78% of total production. Root turnover rates ranged from 0.04 to 0.60 y-1 and consistently decreased as the root size class distribution increased from fine to coarse roots, indicating differences in root longevity. Fine root biomass was negatively correlated with soil P density and frequency of inundation, whereas fine root turnover decreased with increasing soil N:P ratios. Lower P availability in Taylor River basin relative to Shark River basin, along with higher regulator and hydroperiod stress, confirms our hypothesis that interactions of stress from resource limitation and long duration of hydroperiod account for higher fine root biomass along with lower fine root production and turnover. Because fine root production and organic matter accumulation are the primary processes controlling soil formation and accretion in scrub mangrove forests, root dynamics in the P-limited carbonate ecosystem of south Florida have a major controlling role as to how mangroves respond to future impacts of sea-level rise. © 2011 Springer Science+Business Media, LLC.
Zhu Y.,University of Florida |
Gu B.,University of Florida |
Irick D.L.,University of Florida |
Ewe S.,Ecology and Environment Inc. |
And 5 more authors.
Environmental Pollution | Year: 2014
Abstract Tree islands are habitat for wading birds and a characteristic landscape feature in the Everglades. A total of 93 surface soil and 3 soil core samples were collected from 7 degraded/ghost and 34 live tree islands. The mean Hg concentration in surface soils of ghost tree islands was low and similar to marsh soil. For live tree islands, Hg concentrations in the surface head region were considerably greater than those in mid and tail region, and marsh soils. Hg concentrations in bird guano (286 μg kg-1) were significantly higher than those in mammal droppings (105 μg kg-1) and plant leaves (53 μg kg-1). In addition, Hg concentrations and δ15N values displayed positive correlation in soils influenced by guano. During 1998-2010, estimated annual Hg deposition by guano was 148 μg m-2 yr-1 and ∼8 times the atmospheric deposition.
Huq P.,University of Delaware |
Franzese P.,Ecology and Environment Inc.
Boundary-Layer Meteorology | Year: 2013
Water-tunnel measurements of velocity, turbulence and scalar concentration for three model urban canopies with aspect ratios Ar of building height-to-width of 0. 25, 1 and 3 are presented. The measurements for the canopies with Ar = 1 and 3 are new, while the measurements for Ar = 0. 25 were previously published. A passive scalar was continuously released from a near-ground point source, and the concentration was measured at several distances from the source and at different heights above the ground. Plume spreads, concentration and distance from the source were non-dimensionalized using length, time and velocity scales reflecting the geometry of the buildings. The scaling collapses the data for all aspect ratios and is valid when the vertical extent of the plume is smaller than the canopy height. The observed plume spreads are compared with analytical relations, which predict linear growth in both transverse and vertical directions. The observed mean concentration is compared with a Gaussian dispersion model that predicts a -2 power-law decay with distance from the source. © 2012 Springer Science+Business Media Dordrecht.
Roy D.,Nicholls State University |
Roy D.,North Dakota State University |
Hassan K.,Ecology and Environment Inc. |
Boopathy R.,Nicholls State University
Journal of Industrial Microbiology and Biotechnology | Year: 2010
The United States Marine Shrimp Farming Program (USMSFP) introduced a new technology for shrimp farming called recirculating raceway system. This is a zero-water exchange system capable of producing high-density shrimp yields. However, this system produces wastewater characterized by high levels of ammonia, nitrite, and nitrate due to 40% protein diet for the shrimp at a high density of 1,000 shrimp per square meter. The high concentrations of nitrate and nitrite (greater than 25 ppm) are toxic to shrimp and cause high mortality. So treatment of this wastewater is imperative in order to make shrimp farming viable. One simple method of treating high-nitrogen wastewater is the use of a sequencing batch reactor (SBR). An SBR is a variation of the activated sludge process, which accomplishes many treatment events in a single reactor. Removal of ammonia and nitrate involved nitrification and denitrification reactions by operating the SBR aerobically and anaerobically in sequence. Initial SBR operation successfully removed ammonia, but nitrate concentrations were too high because of carbon limitation in the shrimp production wastewater. An optimization study revealed the optimum carbon to nitrogen (C:N) ratio of 10:1 for successful removal of all nitrogen species from the wastewater. The SBR operated with a C:N ratio of 10:1 with the addition of molasses as carbon source successfully removed 99% of ammonia, nitrate, and nitrite from the shrimp aquaculture wastewater within 9 days of operation. © Society for Industrial Microbiology 2010.
Kauffman-Axelrod J.L.,Ecology and Environment Inc. |
Steinberg S.J.,Humboldt State University
Wetlands | Year: 2010
Recent geographic information system (GIS) mapping of Oregon's tidal wetlands identified over 2,000 potential restoration areas. Given the large number of restoration opportunities, we developed automated GIS tools to assist resource managers in prioritizing areas with less hydrologic alteration and more favorable landscape scale metrics. The Coos estuary and watershed was used as an example of a regional application. We developed nine GIS tools using scripting techniques to prioritize among 530 potential restoration sites using widely available state-wide datasets. Parameters evaluated were limited to factors affecting a site's hydroperiod at multiple scales and reflecting consideration of ecological principles. Tabular model output was used to prioritize potential restoration sites. Prioritization ranks were calculated using a three-tier weighted summation designated by Coos estuary restoration practitioners. Standardized ranks ranged from 0.479-1.000 on a zero to one scale. Higher ranks indicate more favorable landscape scale metrics and less cumulative hydrologic alteration. Model output, standardized parameter scores, and prioritized rankings of potential restoration sites were stored in a Microsoft Access database coupled with a geodatabase containing spatial geometry. These automated tools present repeatable and flexible methods for evaluation and prioritization of a large number potential restoration sites in Oregon. © 2010 Society of Wetland Scientists.
Chen H.,South Florida Water Management District |
Vaughan K.,Ecology and Environment Inc.
Wetlands | Year: 2014
The influence of inundation depth on phytomass, shoot density, photosynthesis, elongation, and nutrients of Typha domingensis in Stormwater Treatment Area-1East (STA-1East) was examined and results were evaluated relative to phosphorus (P) treatment from 2006 to 2011. Biomass and nutrient concentrations of T. domingensis were not related to inundation depth. Necromass and belowground/leaf biomass ratio increased with increasing inundation depth from 30 to 80 cm. Shoot density, photosynthesis, and elongation decreased with inundation depth. The contents of necromass nutrients and phytomass nitrogen increased with inundation depth. Annual total P (TP) concentration increase (-) or decrease (+) from inflow to outflow was -21 %, -3 %, + 8 %, -54 %, +41 %, and +29 % in 2006-2011, respectively. Decreases in soluble reactive P (SRP), total dissolved P (TDP), dissolved organic P (DOP), and/or particulate P (PP) from inflow to outflow were low or did not occur annually. Prolonged inundation damaged T. domingensis community and thus adversely impacted the capacity of the system to treat P. Inundation depths in the STAs can be categorized into optimal, subtle stress, and lethal stress zones. This study stressed the importance in maintaining vegetation within an optimal zone of inundation for a sustainable system. © Society of Wetland Scientists 2013.
Daughdrill W.H.,Ecology and Environment Inc. |
Higgins M.E.,Ecology and Environment Inc.
Offshore Technology Conference, Proceedings | Year: 2011
The US Department of the Interior, Minerals Management Service (now renamed Bureau of Offshore Energy Management, Regulation, and Enforcement, BOEMRE) published comprehensive new regulations in the Federal Register applicable to renewable energy and alternate use of facilities on the Outer Continental Shelf (OCS). These new regulations apply to offshore renewable energy projects such as proposed wind farms, wave farms, or ocean current energy extraction devices located in federal waters of the OCS. A discussion covers how this new regulatory process has evolved and what it means to developers of offshore renewable energy project on the OCS; the progress that has been made in defining the regulatory framework; some of the regulatory issues that continue to present challenges in obtaining timely permitting decisions from US federal regulatory authorities, e.g., issues related to the potential environmental impact of offshore renewable energy projects. This is an abstract of a paper presented at the Offshore Technology Conference 2011 (Houston, TX 5/2-5/2011).
Ecology and Environment Inc. | Date: 2010-06-04
A computer based system for managing vehicles, including: a memory unit for at least one specially programmed computer, for storing a request from a first user regarding a trip including a starting point, destination, and schedule. The system includes a processor for the computer for receiving a request from a second user regarding a trip including a starting point, a destination, and a schedule. The processor calculates whether the requests are compatible by calculating whether the following are true: the starting points are within a range of each other; the destinations are within a range of each other; and the schedules are within a range of each other. If the requests are compatible, the processor is for: assigning a vehicle from a plurality of vehicles to the requests; and displaying a notification regarding the assignment of the vehicle.
Ecology and Environment Inc. | Date: 2013-09-11
A computer-based method for gamifying ride sharing, including: storing computer readable instructions in at least one memory element of at least one computer; and executing, using at least one processor for the at least one computer, the computer readable instructions to: accept a first input including a sign-up by a user for a game; accept a second input including information regarding single occupant vehicle trips reduced by the user; assign, according to the information, a position of the user on a virtual board for the game, a ranking of the user in the game and at least one reward to the user; and transmit, for display, a graphical representation of the virtual board including the position of the user.
PubMed | Duke University and Ecology and Environment Inc.
Type: | Journal: PeerJ | Year: 2016
Bird-window collisions cause an estimated one billion bird deaths annually in the United States. Building characteristics and surrounding habitat affect collision frequency. Given the importance of collisions as an anthropogenic threat to birds, mitigation is essential. Patterned glass and UV-reflective films have been proven to prevent collisions. At Duke Universitys West campus in Durham, North Carolina, we set out to identify the buildings and building characteristics associated with the highest frequencies of collisions in order to propose a mitigation strategy. We surveyed six buildings, stratified by size, and measured architectural characteristics and surrounding area variables. During 21 consecutive days in spring and fall 2014, and spring 2015, we conducted carcass surveys to document collisions. In addition, we also collected ad hoc collision data year-round and recorded the data using the app iNaturalist. Consistent with previous studies, we found a positive relationship between glass area and collisions. Fitzpatrick, the building with the most window area, caused the most collisions. Schwartz and the Perk, the two small buildings with small window areas, had the lowest collision frequencies. Penn, the only building with bird deterrent pattern, caused just two collisions, despite being almost completely made out of glass. Unlike many research projects, our data collection led to mitigation action. A resolution supported by the student government, including news stories in the local media, resulted in the application of a bird deterrent film to the building with the most collisions: Fitzpatrick. We present our collision data and mitigation result to inspire other researchers and organizations to prevent bird-window collisions.