Identifying multiple factors limiting long-term success in environmental watering

2020 ◽  
Vol 71 (2) ◽  
pp. 238
Author(s):  
Rebecca E. Lester ◽  
Heather M. McGinness ◽  
Amina E. Price ◽  
Ashley Macqueen ◽  
N. LeRoy Poff ◽  
...  
Keyword(s):  
Limiting Factors ◽  
Migratory Fish ◽  
Short Term ◽  
Major Life ◽  
Life History Stages ◽  
Colonial Nesting ◽  
Management Actions ◽  
Ecological Objectives ◽  
Population Maintenance

Environmental watering is frequently used to achieve specific ecological objectives, such as triggering spawning or seed germination. These short-term objectives are often met, but longer-term objectives, such as population growth, may not be, especially where multiple hydrological and non-hydrological factors influence success. We propose a framework to identify these factors in space and time. Our framework steps users through identifying possible inhibiting (strictures) and supporting (promoters) factors, and placing these factors in their spatial and temporal context. This allows users to identify potential limiting factors that may require additional intervention, or render the original watering action unsustainable. We illustrate the framework with examples of a floodplain tree (black box, Eucalyptus largiflorens), colonial nesting waterbird (royal spoonbill, Platalea regia) and large-bodied migratory fish (golden perch, Macquaria ambigua). The framework explores strictures and promoters for major life-history stages, emphasising the need to support and protect all stages if objectives include population maintenance or growth. In this way, the framework can document existing mental models and can be used as the basis of a risk portfolio, a prioritisation tool or future quantitative models. Thus, the framework enables individual management actions to be better grounded in a broader context, increasing the likelihood of achieving long-term ecological objectives.

scholarly journals Addressing fish-passage issues at hydropower and irrigation infrastructure projects in Indonesia

2018 ◽  
Vol 69 (12) ◽  
pp. 1805 ◽  
Author(s):  
Lee J. Baumgartner ◽  
Arif Wibowo
Keyword(s):  
Life History ◽  
Fish Passage ◽  
Mitigation Measures ◽  
Migratory Fish ◽  
Tropical Island ◽  
Life History Stages ◽  
Barrier Effects ◽  
Sumatra Island ◽  
Irrigation Infrastructure

Development activities threaten the long-term sustainability of tropical floodplain systems. The construction of dams, weirs, irrigation infrastructure and regulators affect connectivity among habitats and can facilitate rapid declines in riverine biota, especially fish. Indonesia is a tropical island country with an abundance of monsoonal rivers. Massive expansions in hydropower and irrigation infrastructure are planned over the next two decades and mitigation measures will be needed to protect migratory fish. Most Indonesian freshwater fish need to migrate among habitats to complete essential life-history stages. So, strategies are urgently needed to mitigate the barrier effects of river infrastructure to ensure the long-term sustainability of river fishes. A common tool used worldwide is the construction of upstream and downstream fish passes. Only two fish passes exist in Indonesia. One at Perjaya Irrigation Dam on the Komering River (Sumatra island) and another on Poso Dam on the Poso River (Sulawesi island). Neither of these structures has been assessed and many other projects are proceeding without considering potential impacts on fisheries. The proposed infrastructure upgrades over the next two decades provide a once-in-a-generation opportunity to ensure that migratory fish are adequately protected into the future.

scholarly journals Short-term exposure of Chinook salmon (Oncoryhnchus tshawytscha) to o,p-DDE or DMSO during early life-history stages causes long-term humoral immunosuppression.

2003 ◽  
Vol 111 (13) ◽  
pp. 1601-1607 ◽  
Author(s):  
Ruth H Milston ◽  
Martin S Fitzpatrick ◽  
Anthony T Vella ◽  
Shaun Clements ◽  
Deke Gundersen ◽  
...  
Keyword(s):  
Life History ◽  
Chinook Salmon ◽  
Early Life ◽  
Early Life History ◽  
Short Term ◽  
Life History Stages ◽  
Short Term Exposure

scholarly journals The evolving relationship between airline profitability and passenger satisfaction

2013 ◽  
Vol 24 (1) ◽  
pp. 7-21
Author(s):  
Kent N Gourdin
Keyword(s):  
Airline Industry ◽  
Structural Changes ◽  
Business Models ◽  
Quality Model ◽  
Short Term ◽  
The Past ◽  
Management Actions ◽  
Passenger Satisfaction ◽  
The U.S

This paper examines the ongoing evolution of the U.S. airline industry under deregulation. After losing money for most of the past 35 years, carriers have made structural changes to their business models that have proven to be, at least in the short term, very profitable. After delineating these management actions, the paper examines their impact on passengers. The author utilizes the Service Quality Model to analyze the long-term implications of this new operating paradigm for passenger satisfaction. Based on this analysis the paper goes on to suggest several actions management could take to improve satisfaction. Finally, conclusions are offered and areas for additional research suggested.

scholarly journals Anthropogenic river fragmentation reduces long-term viability of the migratory fish Salminus brasiliensis (Characiformes: Bryconidae) populations

2021 ◽  
Vol 19 (2) ◽  
Author(s):  
Josiane Ribolli ◽  
Evoy Zaniboni-Filho ◽  
Carolina Barros Machado ◽  
Tailise Carolina de Souza Guerreiro ◽  
Patrícia Domingues de Freitas ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Anthropogenic Impacts ◽  
Species Conservation ◽  
Migratory Fish ◽  
Effective Population ◽  
Long Distance ◽  
Management Actions ◽  
Population Structure Analysis ◽  
Salminus Brasiliensis

Abstract Life-history, geographical barriers, and damming can shape the genetic diversity of freshwater migratory fish, which are particularly vulnerable to anthropogenic impacts. We investigated the genetic diversity of Salminus brasiliensis, a long-distance migratory species that is recognized as an important provider of ecosystem services. We implemented microsatellite analyses to assess genetic diversity and simulate future scenarios for evaluating the long-term viability of dammed and non-dammed populations from the Uruguay River. High levels of genetic diversity were detected for all sampled populations. However, effective population sizes were lower in the uppermost river stretches, where the landscape is highly fragmented. Population structure analysis indicated two spatial genetic populations. It is suggested that this genetic structure preserves populations partially isolated by an ancient natural barrier, instead of being a result of the presence of dams. The simulated genetic scenarios indicated that genetic variability of S. brasiliensis populations from upstream dams could collapse over the years, mainly due to the reduction in the number of alleles. Therefore, besides helping to better understand issues related to the influence of dams on the genetic diversity of migratory fish, our results are especially relevant for driving local fishery policies and management actions for the species conservation.

scholarly journals Hyper-Nutrient Enrichment Status in the Sabalan Lake, Iran

Water ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 2874
Author(s):  
Roohollah Noori ◽  
Elmira Ansari ◽  
Yong-Wook Jeong ◽  
Saber Aradpour ◽  
Mohsen Maghrebi ◽  
...  
Keyword(s):  
Nutrient Enrichment ◽  
Management Practices ◽  
Storage Capacity ◽  
Limiting Factors ◽  
Molar Ratio ◽  
Anthropogenic Factors ◽  
Short Term ◽  
Reservoir Water ◽  
P Deficiency

Lakes/reservoirs are rapidly deteriorating from cultural eutrophication due to anthropogenic factors. In this study, we aimed to (1) explore nutrient levels in the Sabalan dam reservoir (SDR) of northwest Iran, (2) determine the reservoir water fertility using the total phosphorus (TP)based and total nitrogen (TN)based Carlson trophic state indices, and (3) specify primary limiting factors for the reservoir eutrophication. Our field observations showed a state of hyper-nutrient enrichment in the SDR. The highest variation of TN in the reservoir water column happened when the reservoir was severely stratified (in August) while the highest variation of TP took place when the thermocline was attenuated with the deepening of the epilimnion (in October). Both TP and TN based trophic indicators classified the SDR as a hypereutrophic lake. TN:TP molar ratio averaged at the epilimnion indicated a P–deficiency in the reservoir during warm months whilst it suggested a co–deficiency of P and N in cold months. Given the hyper-nutrient enrichment state in the reservoir, other drivers such as water residence time (WRT) can also act as the main contributor of eutrophication in the SDR. We found that WRT in the SDR varied from hundreds to thousands of days, which was much longer than that of other reservoirs/lakes with the same and even much greater storage capacity. Therefore, both hyper-nutrient enrichment and WRT mainly controlled eutrophication in the reservoir. Given time consuming and expensive management practices for reducing nutrients in the watershed, changes in the SDR operation are suggested to somewhat recover its hypereutrophic state in the short-term. However, strategic long-term recovery plans are required to reduce the transition of nutrients from the watershed to the SDR.

scholarly journals Red-Cockaded Woodpecker Habitat and Timber Management: Production Possibilities

1990 ◽  
Vol 14 (1) ◽  
pp. 6-12 ◽  
Author(s):  
Joseph Roise ◽  
Joosang Chung ◽  
Richard Lancia ◽  
Mike Lennartz
Keyword(s):  
Management Strategies ◽  
Habitat Requirements ◽  
Multiple Objective ◽  
Multiple Objective Linear Programming ◽  
Timber Management ◽  
Negative Effects ◽  
Short Term ◽  
Management Actions ◽  
Red Cockaded Woodpecker

Abstract To mitigate possible negative effects that financial timber rotations for southern pine may have on habitat requirements for red-cockaded woodpeckers, alternative management strategies are investigated using multiple objective linear programming (MOLP). Time streams of timber and habitat are examined. The consequence of providing areas with potential cavity trees on production of timber is explored. Management actions which immediately set aside large areas of land for woodpecker habitat without concern for future changes can lead to short-term increases in habitat that are followed by habitat declines after several decades. Management actions designed to restructure the forest to achieve a long-term sustainable habitat level may initially have a slower increase in habitat, but without subsequent declines. South. J. Appl. For. 14(1):6-12

scholarly journals Long-term monitoring of nitrate transport to drainage from three agricultural clayey till fields

2015 ◽  
Vol 19 (8) ◽  
pp. 3475-3488 ◽  
Author(s):  
V. Ernstsen ◽  
P. Olsen ◽  
A. E. Rosenbom
Keyword(s):  
Water Management ◽  
Aquatic Environment ◽  
Nitrate Transport ◽  
Field Scale ◽  
Short Term ◽  
Management Actions ◽  
Nitrate N ◽  
Air Temperatures ◽  
N Fertilisers

Abstract. The application of nitrogen (N) fertilisers to crops grown on tile-drained fields is required to sustain most modern crop production, but it poses a risk to the aquatic environment since tile drains facilitate rapid transport pathways with no significant reduction in nitrate. To maintain the water quality of the aquatic environment and the provision of food from highly efficient agriculture in line with the EU's Water Framework Directive and Nitrates Directive, field-scale knowledge is essential for introducing water management actions on-field or off-field and producing an optimal differentiated N-regulation in future. This study strives to provide such knowledge by evaluating on 11 years of nitrate-N concentration measurements in drainage from three subsurface-drained clayey till fields (1.3–2.3 ha) representing approximately 71 % of the surface sediments in Denmark dominated by clay. The fields differ in their inherent hydrogeological field settings (e.g. soil-type, geology, climate, drainage and groundwater table) and the agricultural management of the fields (e.g. crop type, type of N fertilisers and agricultural practices). The evaluation revealed three types of clayey till fields characterised by: (i) low net precipitation, high concentration of nitrate-N, and short-term low intensity drainage at air temperatures often below 5 °C; (ii) medium net precipitation, medium concentration of nitrate-N, and short-term medium-intensity drainage at air temperatures often above 5 °C; and (iii) high net precipitation, low concentration of nitrate-N and long-term high intensity drainage at air temperatures above 5 °C. For each type, on-field water management actions, such as the selection of crop types and introduction of catch crops, appeared relevant, whereas off-field actions only seemed relevant for the latter two field types given the temperature-dependent reduction potential of nitrate off-field. This initial well-documented field-scale knowledge from fields that are representative of large areas in Denmark is a first step towards establishing a differentiated N-regulation for clayey till areas. Additionally, it provides a unique starting point by identifying important parameters for future mapping of catchment-scale variations in nitrate concentrations and fluxes.

scholarly journals Investigation of Short-term Amplitude and Frequency Fluctuations of Lasers for Interferometry

2013 ◽  
Vol 13 (2) ◽  
pp. 63-69 ◽  
Author(s):  
J. Hrabina ◽  
J. Lazar ◽  
M. Holá ◽  
O. Číp
Keyword(s):  
Detection System ◽  
Laser Interferometry ◽  
Limiting Factors ◽  
Laser Source ◽  
Short Term ◽  
Term Frequency ◽  
Laser Sources ◽  
Frequency Fluctuations ◽  
Frequency Variations

One of the limiting factors of accuracy and resolution in laser interferometry is represented by noise properties of the laser powering the interferometer. Amplitude and especially frequency fluctuations of the laser source are crucial in precision distance measurement. Sufficiently high long-term frequency stability of the laser source must be achieved especially in applications in fundamental metrology. Furthermore, the short-term frequency variations are also important primarily for measurements done at high acquisition speeds. This contribution presents practical results of measurements of short-term amplitude and frequency noises of a set of laser sources commonly used in laser interferometry. The influence of the interferometer design and electrical parameters of the detection system are also discussed.

Rediscovery of an endangered frog Platymantis vitianus, on mainland Fiji: implications for conservation and management

2004 ◽  
Vol 10 (4) ◽  
pp. 237 ◽  
Author(s):  
C. Morrison ◽  
A. Naikatini ◽  
N. Thomas ◽  
I. Rounds ◽  
B. Thaman Niukula
Keyword(s):  
Key Management ◽  
Pacific Region ◽  
Short Term ◽  
Management Actions ◽  
The Pacific ◽  
Introduced Predators ◽  
Threatening Processes ◽  
Conservation And Management

Many herpetofauna species in the Pacific region have undergone dramatic declines due to invasive species, primarily introduced predators. Fiji has two species of endemic frogs (Family Ranidae, Genus Platymantis) one of which, the Fiji Ground Frog, P. vitianus, has been extirpated from much of its original range due to the mongoose Herpestes javanicus. We conducted a short-term follow up survey to confirm an earlier report (September 2003) of the co-existence between mongoose and the ground frog on mainland Fiji (Vanua Levu). We used systematic nocturnal and diurnal surveys to census the frog fauna of Waisali Reserve and described microhabitat and threatening processes. A series of key management actions are outlined to facilitate the long-term conservation of this frog in the reserve.

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