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... Fish schools reduce their predators' encounter rates not only by performing evasive maneuvers but also by increasing distances between prey patches. However, a similar challenge applies to isolated prey fish seeking refuge during periods of diel school formation. We demonstrate with an Ideal Gas movement model that as the stock sizes of a fish who forms schools daily decreases, school densities do ...
stockingrate, etc ; environmental economics; fish; fisheries management; renewable resources; resource management; Show all 6 Subjects
Abstract:
... This article analyses the effect of productivity improvements on optimal fisheries management. It is shown that when harvest costs are independent of resource stock and the stock is below its steady state level, then for any given stock it is optimal to reduce harvest levels in response to a productivity increase unless optimal harvest rate is already zero. If harvest costs are stock dependent thi ...
stockingrate, etc ; Coregonus; egg production; fecundity; gillnets; lakes; mortality; risk; Show all 8 Subjects
Abstract:
... Vendace is commonly assumed at low risk to recruitment overfishing. This assumption has been confirmed for boreal stocks but might not apply at lower latitudes. We evaluated the risk of recruitment overfishing at the southernmost extent of vendace populations by comparing fecundity, natural mortality, and fishing mortality of two stocks differing in growth with those of a population not subject to ...
stockingrate, etc ; Mallotus villosus; fish; research; time series analysis; uncertainty; Barents Sea; Show all 7 Subjects
Abstract:
... It is assumed that maturation in the Barents Sea capelin is length-dependent, and that fish of at least 14 cm will potentially spawn. Current assessment and management models for the stock are based on this assumption of constant maturity at length (MaL). Using data from scientific surveys, this paper examines the validity of the constant MaL assumption, and contrasts it with maturation based on e ...
stockingrate, etc ; autumn; ecological restoration; herds; landscapes; national parks; shrubs; spring; summer; wetlands; Show all 10 Subjects
Abstract:
... Wetlands are often exposed to reed and shrub expansion that dominate their heterogeneous landscape and threaten species inhabiting open wetlands. The alternative to heavy‐machine mowing is grazing, which should be carried out without fencing in high‐value protected areas. To evaluate the effectiveness of semi‐free‐ranging cattle in sustaining and restoring the open landscape of heterogeneous wetla ...
stockingrate, etc ; cattle; ecosystems; forage; grasslands; greenhouses; pasture management; pastures; rangelands; soil carbon; Canada; Show all 11 Subjects
Abstract:
... Significant interest exists in the potential for specialized grazing systems, including adaptive multipaddock (AMP) grazing, to enhance grassland health and function. However, specific pasture management practices associated with AMP grazing at the ranch level remain poorly understood in comparison with more regionally representative management systems. As part of a larger study examining grazing ...
stockingrate, etc ; Markov chain; biomass; economic performance; fish; fisheries; issues and policy; research; uncertainty; Show all 9 Subjects
Abstract:
... This paper deals with mathematical modelling of strategies in harvesting of fish populations. Since too aggressive harvesting may have severe consequences, a cautious control of the process is called for. The determination of optimal harvesting based on the biomass size is made even more challenging since there is considerable uncertainty in the estimation of the stock size, the so-called incomple ...
stockingrate, etc ; bioeconomic models; equations; prices; Show all 4 Subjects
Abstract:
... In this paper, we study a mathematical bio-economic model of a fishery with varying price. The three dimensional model describes the time evolution of the resource, the fishing effort and the price. The model is original because it considers a nonlinear harvesting function assumed to depend upon stock size and fishing effort with a saturation effect with respect to the resource as well as a price ...
stockingrate, etc ; carbon; carbon sinks; climate change; cropland; food security; forests; grasslands; humus; land use; meteorology; mineral soils; overstory; silvopastoral systems; species diversity; sustainable land management; tree age; trees; understory; Alberta; Show all 20 Subjects
Abstract:
... Agroforestry systems (AFS) are increasingly being recognized as sustainable land-use systems that can increase carbon (C) sequestration and improve food security. However, the relative contributions of various C pools to the overall C stock of AFS and their dependence on factors such as tree age, species diversity and density is still unclear in many regions. Using an equivalent soil mass approach ...
stockingrate, etc ; Castanea sativa; canopy; coppicing; ecosystems; forest management; forests; leaf area index; lidar; linear models; research; Show all 11 Subjects
Abstract:
... The Leaf Area Index (LAI) is a key parameter that helps to understand the connection between canopy structure and ecosystem functions. In this study, the main aims were to examine the impact of forest management on canopy structure using LiDAR data to characterize the canopy vertical profile, as well as to develop LAI models and an LAI mapping tool for sweet chestnut (Castanea Sativa Mill.) coppic ...
stockingrate, etc ; Picea abies; birds; comparative study; dead wood; habitats; landscapes; silviculture; species diversity; stand age; stand development; Estonia; Show all 12 Subjects
Abstract:
... KEY MESSAGE: Bird assemblages in planted spruce (Picea abies L.) forests were compositionally distinct from those in naturally regenerated mixed stands. Despite rapid stand development on productive soils, even-aged silviculture cannot host most old-forest species. However, their habitat quality could be supported in landscape mosaics with retention forestry and set-asides. CONTEXT: The most produ ...
stockingrate, etc ; circular economy; construction materials; data quality; energy; urbanization; Show all 6 Subjects
Abstract:
... Better knowledge of the spatial distribution of anthropogenic stocks is key for the implementation of circular economy policies. This article focuses on the case of construction materials in the Paris region in 2013. A bottom-up approach using GIS modeling is applied to estimate and locate the stocks of 27 materials and 24 building archetypes, three transport networks and six energy and water netw ...
stockingrate, etc ; Australians; data collection; exhibitions; market analysis; markets; prices; Show all 7 Subjects
Abstract:
... This paper examines the role of information release in explaining the return volatility of the Australian equity market. The study applies proxies of greater accuracy to examine the effect of public and private information on return volatility. Analyst price targets (PTR) and Morningstar stock star ratings (MSR) were used as private information proxies while Australian Securities Exchange (ASX) an ...
stockingrate, etc ; Strongylocentrotus purpuratus; aquaculture; aquaculture industry; cages; infrastructure; rearing; Show all 7 Subjects
Abstract:
... Finding the ideal density to optimise growth, health and welfare of aquaculture species reared in cage or tank environments allows farmers to produce the best quality product per unit area. Appropriate stocking densities are well known for most major aquaculture species, but limited information exists for the developing sea urchin aquaculture industry. The temperate purple sea urchin Heliocidaris ...
... Fisheries management typically aims at controlling exploitation rate (e.g., Fbar) to ensure sustainable levels of stock size in accordance with established reference points (e.g., FMSY, BMSY). Population selectivity (“selectivity” hereafter), that is the distribution of fishing mortality over the different demographic components of an exploited fish stock, is also important because it affects both ...
stockingrate, etc ; biodiversity; clearcutting; forests; habitat fragmentation; landscapes; politics; socialism; wood; Poland; Show all 10 Subjects
Abstract:
... At all times, historical, political, economic, and social factors have affected the management of forests, with direct and indirect effects on the landscape. This study aimed to trace the impact of Poland’s forestry evolution over the last 75 years (1945–2020) on forest biodiversity at the landscape level. Five indicators were selected (forest area, forest fragmentation, protected forests, protect ...
stockingrate, etc ; Arctica islandica; Spisula solidissima; experimental design; models; research; surveys; uncertainty; Show all 8 Subjects
Abstract:
... Between 1997 and 2011, The National Marine Fisheries Service conducted 50 depletion experiments to estimate survey gear efficiency and stock density for Atlantic surfclam (Spisula solidissima) and ocean quahog (Arctica islandica) populations using commercial hydraulic dredges. A model formulated for this purpose, the Patch Model, was used to estimate gear efficiency and organism density. The range ...
stockingrate, etc ; USSR; energy efficiency; global change; industrialization; infrastructure; metabolism; models; China; Show all 9 Subjects
Abstract:
... Material stocks in infrastructure, buildings and machinery shape current and future resource use and emissions. Analyses of specific countries and selected materials suggest that material stocks might saturate, which would be important for a more sustainable social metabolism. However, it is unclear to what extent the evidence holds for a wider range of stocks and flows, as well as for world regio ...
stockingrate, etc ; Large White; body weight; industry; males; rearing; regression analysis; turkeys; Show all 8 Subjects
Abstract:
... Industry standards for turkey stocking densities are variable and may not represent the more rapidly growing strains currently available. Therefore, a study was completed to evaluate 4 stocking densities: a nominal density (0.3525 m²/bird), 10% tighter density (0.3169 m²/bird), 10% looser density (0.3882 m²/bird), and 20% looser density (0.4238 m²/bird) on the effects on large white, commercial ma ...
stockingrate, etc ; growth performance; mackerel; marine science; mortality; yield forecasting; Mediterranean region; Show all 7 Subjects
Abstract:
... A preliminary assessment of stock size and status of Trachurus mediterraneus and T. trachurus species were investigated via virtual population and yield prediction analyses using onboard collected length-frequency data from Northeastern Mediterranean. The length-frequency based VBGF parameters and growth performance index were L∞=28 cm, k=0.62, t0=0.58, tanc=0.52 and Φ′=2.69 for T. mediterraneus a ...