scholarly journals Physical and biological constraints on the capacity for life-history expression of anadromous salmonids: an Eel River, California, case study

2021 ◽  
Author(s):  
Alyssa M FitzGerald ◽  
David Boughton ◽  
Joshua Fuller ◽  
Sara N John ◽  
Benjamin T. Martin ◽  
...  
Keyword(s):  
Life Histories ◽  
Thermal Sensitivity ◽  
Life Stage ◽  
High Elevation ◽  
Biological Interactions ◽  
Eel River ◽  
Geomorphic Features ◽  
Ptychocheilus Grandis ◽  
Sacramento Pikeminnow

Recovery of anadromous salmonid populations is complicated by their complex life-histories. We examined the spatiotemporal interplay of stream temperature, geomorphic features, and a species’ thermal sensitivity mediated by biological interactions in a case study of steelhead trout (Oncorhynchus mykiss) and Chinook salmon (O. tshawytscha) in California’s Eel River watershed. We estimated habitat suitability and fish capacity for each salmonid run and freshwater life stage during average, cool, and warm years in each of the watershed’s subbasins, including a historically-occupied high-elevation subbasin upstream of an impassable dam. Our estimates varied depending on whether we accounted for exposure to the Sacramento pikeminnow (Ptychocheilus grandis), an introduced predator/competitor. Our results indicate that the dammed subbasin has substantial salmonid capacity relative to the rest of the watershed and could provide an important cool-water refuge during warm years and from pikeminnow, potentially improving the productivity and resilience of multiple anadromous salmonid populations. Our approach can be applied in any setting where spatially explicit habitat metrics can be estimated and population specific and life-stage specific habitat criteria can be specified.

scholarly journals Farmer Preference to High Elevation Rice Technological Packages for Accelerating Technological Dissemination (A case Study in Humbang Hasundutan Regency)

Agro Ekonomi ◽  
2021 ◽  
Vol 32 (2) ◽  
Author(s):  
Setia Sari Girsang ◽  
Agung B Santosa ◽  
Tommy Purba ◽  
Deddy R Siagian ◽  
Khadijah E Ramija
Keyword(s):  
Low Cost ◽  
High Elevation ◽  
Primary Data ◽  
Survey Method ◽  
User Friendliness ◽  
Level Of Satisfaction ◽  
High Level ◽  
Level Of Importance

Accelerating the introduction of a new technological package is needed to increase the productivity of high elevation puddled rice in Humbang Hasundutan. The objectives of the study are to find out the perception of the existence of technological packages and farmers' preference for a new technological package. The study used a survey method with primary data gathered using questionnaires. The criteria of locations and respondents were used to obtain relevant respondents and data concerning their knowledge of high elevation puddled rice cultivation.  The collected data were processed by using Importance Performance Analysis in order to find out the level of Importance and Satisfaction of the indicators and the valued aspects in the technological package components. The results of the study showed that the socio-economic aspects had to be heeded in organizing the technological package. Indicators having a high level of importance and a low level of satisfaction consisted of production cost, quality of seeds, farmer groups empowerment, technology information institution, capital cost, agricultural tools and machines, pest control, sales price, irrigation canals, and farm roads. On the other hand, introducing new superior seeds, productivity attribute and planting age were important indicators for local farmers as to improve the quality of existing seeds. Farmers group expected that the technological package had a high level of productivity, better access to input, low cost, and good user-friendliness in its application.

Beyond Economics

2018 ◽  
pp. 123-144
Author(s):  
Florent Audy
Keyword(s):  
Life Histories ◽  
Viking Age ◽  
The Social ◽  
Key Features ◽  
Long Life ◽  
The Aesthetic ◽  
Technical Features

In this chapter, the social, symbolic, and cultural attributes of Viking Age silver is addressed through an exploration of coin-pendants: coins taken out of circulation and suspended on necklaces to be worn as jewellery. Surveying material from a newly collated dataset, the chapter first outlines the key features of coin-pendants from across Scandinavia, including the rate of transformation of different coin types and their technical features. It then addresses the question: what made coin-pendants desirable? Discussion considers the aesthetic and bullion content of the pendants, as well as their value as exotic items and/or as items with long life histories. A case study is presented of an Arabic dirham-pendant, found in an inhumation grave at Birka, Sweden.

scholarly journals Thermal performance curves reveal shifts in optima, limits and breadth in early life

2020 ◽  
Vol 223 (22) ◽  
pp. jeb233254
Author(s):  
Adriana P. Rebolledo ◽  
Carla M. Sgrò ◽  
Keyne Monro
Keyword(s):  
Embryo Development ◽  
Thermal Performance ◽  
Early Life ◽  
Thermal Sensitivity ◽  
Life Stage ◽  
Life Stages ◽  
Parametric Bootstrapping ◽  
Performance Curves ◽  
Survival And Reproduction ◽  
Mixed Modelling

ABSTRACTUnderstanding thermal performance at life stages that limit persistence is necessary to predict responses to climate change, especially for ectotherms whose fitness (survival and reproduction) depends on environmental temperature. Ectotherms often undergo stage-specific changes in size, complexity and duration that are predicted to modify thermal performance. Yet performance is mostly explored for adults, while performance at earlier stages that typically limit persistence remains poorly understood. Here, we experimentally isolate thermal performance curves at fertilization, embryo development and larval development stages in an aquatic ectotherm whose early planktonic stages (gametes, embryos and larvae) govern adult abundances and dynamics. Unlike previous studies based on short-term exposures, responses with unclear links to fitness or proxies in lieu of explicit curve descriptors (thermal optima, limits and breadth), we measured performance as successful completion of each stage after exposure throughout, and at temperatures that explicitly capture curve descriptors at all stages. Formal comparisons of descriptors using a combination of generalized linear mixed modelling and parametric bootstrapping reveal important differences among life stages. Thermal performance differs significantly from fertilization to embryo development (with thermal optimum declining by ∼2°C, thermal limits shifting inwards by ∼8–10°C and thermal breadth narrowing by ∼10°C), while performance declines independently of temperature thereafter. Our comparisons show that thermal performance at one life stage can misrepresent performance at others, and point to gains in complexity during embryogenesis, rather than subsequent gains in size or duration of exposure, as a key driver of thermal sensitivity in early life.

scholarly journals An Integrated Approach to Analyze Sedimentary Stock and Coastal Erosion in Vulnerable Areas: Resilience Assessment of San Vicenzo’s Coast (Italy)

Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 805
Author(s):  
Francesco Bianco ◽  
Paolo Conti ◽  
Salvador García-Ayllon ◽  
Enzo Pranzini
Keyword(s):  
Coastal Erosion ◽  
Integrated Approach ◽  
Coastal Communities ◽  
Sea State ◽  
Erosion Risk ◽  
Geomorphic Features ◽  
Active Processes ◽  
Resilience Assessment ◽  
Morphological Patterns

The assessment of coastal erosion risk is a major challenge, since environmental and geomorphic features, together with sea state parameters, can seriously change the configuration of coastal areas. In addition, the anthropic actions of the coastal communities may also drastically modify the configuration of the coast in vulnerable areas. In this study, a linkage between regional mapping guidelines and national geological cartography procedures is presented as a meaningful tool in the geomorphic trends analysis for the integrated mapping of the main morphological patterns of San Vincenzo’s coastal area, in the region of Tuscany (Italy). Comparing and joining different procedures—which have different scales and topics—requires adapting the fields and the information provided in maps and databases. In this case study, a GIS morpho-sedimentological approach is developed. This GIS approach enables us to cover several issues simultaneously, such as the representation of coastal active processes, the adaptation of regional and national cartography to coastal erosion assessment, and lastly the calculation of the sedimentary stock analysis, since it represents the first attribute of coasts to be preserved in a resilience-oriented integrated assessment.

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