Search results for " fisheries."
showing 10 items of 1015 documents
Varied response of underground and aboveground plant matter: functional diversity of three different vegetational types after translocation to reclai…
2019
The indicators of functional diversity are increasingly used to assess the conservation effectiveness of the most valuable habitats. However, little is known about the response of functional traits, their diversity, and divergence in plant communities after translocation. To assess how functional diversity changes on dry heath, meadow, and fen after translocation of entire turfs of vegetation from an airport area to the Botanical Garden in Radzionkow, we used leaf–height–seed (LHS) traits (specific leaf area, height, and seed mass) and vegetative traits (bud bank size, bud bank depth, and lateral spread). We also measured community weighted means and multifunctional diversity metrics (funct…
New stage-discharge relationship for inclined non-rectangular weirs
2018
Abstract In this paper, the outflow process of inclined non-rectangular weirs is studied applying the dimensional analysis and the incomplete self-similarity theory. At first, a new stage-discharge equation, applicable for the non-rectangular weirs having a different geometrical shape (parabolic, semicircular, inverted semicircular), is theoretically deduced using a characteristic width. Then, this power stage-discharge relationship (Eq. (17) ) is calibrated and tested using measurements carried out by Raiknar for parabolic, semicircular and inverted semicircular weirs having different inclination respect to the vertical (10°, 20°, 30°, 40° and 45°). For each geometrical shape, the analysis…
Effects of progressive decrease of feeding frequency and re-feeding on production parameters, stomach capacity and muscle nutritional value in rainbo…
2020
Abstract Feeds and feeding constitute the major part of costs in intensive aquaculture. Any action to reduce feeding costs without negatively affecting fish production parameters and flesh quality would improve profitability of farming. Therefore, we studied the effects of feeding frequency on production parameters, stomach capacity and nutritional value of muscle in juvenile rainbow trout (Oncorhynchus mykiss) in an experiment with two stages. First, during the nine-week “starvation period” we fed rainbow trout (initial weight c. 40 g) with four different feeding protocols in an attempt to adapt the fish to a progressive decrease in the number of feeding days. During the second stage, a fo…
Effects of weekend starvation and the duration of daily feeding on production parameters of rainbow trout Oncorhynchus mykiss
2021
Abstract It would often be practical to starve the cultivated fishes over the weekends, e.g. to save in labour costs. We evaluated the possibility that domesticated juvenile rainbow trout (Oncorhynchus mykiss) could compensate for the lost growth of the 2-day weekend starvation by either hyperphagic response and/or by lower feed conversion ratio, compared to the fish fed every day in an 8-week experiment. Rainbow trout (initial weight c. 30 g, temperature 16 °C) starved during the weekends were able to increase feed intake during the weekdays clearly above the intake of the control fish after the first two weekends, also seen as an increase of the compensation coefficients over the last fou…
Soil REE patterns as tracers of the emplacement of metal-rich anthropogenic materials. A case study in Moa (Cuba)
2019
Purpose: Are rare earth element (REE) patterns employable as tracers in human interventions of bulk soil disturbances, when high concentrations of metals are involved in the in situ soil disturbance? In terms of bulk soil disturbance, it is difficult to distinguish between bulk soil disturbances and emplacement of new earthen material. Chemical fingerprinting, in particular REE plus yttrium, is applied across many fields, but predominantlyin tracking the sources of potential environmental contaminants. Materials and methods: The REE normalised patterns (HNO 3 :HF:HCl 3:1:1 digestion, ICP-MS) of two Calcaric Cambisols were compared with those of a Geric Ferralsol (Novic, Technic) originated …
Preface: Proceedings of the 14th IASWS international conference
2018
Preface to the Proceedings of the 14th IASWS international conference
Deducing a Drain Spacing Formula by Applying Dimensional Analysis and Self-Similarity Theory
2016
For designing a steady state drainage system a drain flow formula coupled with the Dupuit-Forcheimer form of the differential equation of groundwater flow is used. At first, in this paper the most applied drain flow formulas in steady-state conditions are reviewed and compared using as dependent variable the ratio between the maximum water table height and the distance between two lines of parallel drains. These equation are also tested using experimental field data measured in three plot drained by surface pipe drains having different value of drain spacing. Then, applying the dimensional analysis and the self-similarity theory, a new drain spacing formula is theoretically deduced and comp…
Sustainable vineyard floor management: An equilibrium between water consumption and soil conservation
2018
Abstract Sustainable vineyards soil management can help to mitigate the negative effect of intensive agriculture on soil ecosystem for the achievement of the sustainable development goals. Cover crops use as cover management in vineyard could be considered as nature based solution for soil restoration and proper water management. Cover crops (CC) provide many ecosystem services through carbon sequestration and climate change regulation, water purification and soil protection. However, a holistic approach is needed to understand the maximum potential ecosystem service that can be provided in different soil and climatic condition also considering vineyard needs. The current knowledge of CC ma…
Soil Mapping and Processes Modeling for Sustainable Land Management
2017
Soil maps and models are indispensable tools in sustainable land management. The sustainable land use of our territory is fundamental to providing long-term socio-economic and environmental benefits. The risk of land degradation and corresponding declines in ecosystem services depends on the type of land use. Soil restoration can be extremely expensive, more than the implementation of sustainable land use practices. This is especially important in the context of climate change and the increasing pressure that a growing population places on soil resources, which is a global phenomenon. The objective of this chapter is to show the advantages of using soil mapping and modeling in sustainable l…
Soil Mapping and Processes Models for Sustainable Land Management Applied to Modern Challenges
2017
Abstract In the context of growing population and global change, increasing demands for food production are an enormous challenge that we face in the modern world. At the same time the need to prevent land degradation, restore lands that are already degraded, and maintain soil quality and health is critical to a sustainable use of land resources. Accurate maps and adequate models are indispensable tools to assist managers, scientists, and decision makers in addressing these challenges. In this chapter, we outline the main impacts of climate change on soils, key adaptation, and mitigation strategies and provide an overview of key issues in sustainable agricultural production as well as land …