48 research outputs found
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CTD observations in the coastal transition zone off Northern California, 18-27 June 1988
Wecoma cruise W8806A was conducted in June 1988 as part of the pilot study for the Coastal Transition Zone project. CTD observations were made over a standard grid in the coastal transition zone off northern California between 37° N and 39.5° N that was to be occupied repeatedly during June, July and August; this cruise was to complete the first survey. Altogether 60 stations were completed successfully. They were concentrated along six alongshore transects. Maximum sampling depth at all stations was 500 m. Temperature, salinity, light transmission and fluorescence were measured at all stations. This report presents vertical profile plots and tabulations of data at selected depths for each station; vertical sections of temperature, salinity and potential density anomaly (sigma-theta) for the alongshore sections; and maps of temperature, salinity, potential density anomaly and dynamic topography at selected depths
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CTD observations in the coastal transition zone off Northern California, 9-18 June 1987
Wecoma cruise W8706A was conducted in June 1987 as part of the pilot study for the Coastal Transition Zone project. CTD observations were made in the coastal transition zone off northern California between 37.5°N and 41.5°N and along 43°13'N off Coos Bay, Oregon. Altogether 133 stations were completed successfully. They were concentrated along three alongshore transects, at distances of 60, 90 and 150 km from the coast. Maximum sampling depth at most stations was 500 m. Temperature, salinity, light transmission and fluorescence were measured at all stations. This report presents vertical profile plots and tabulations of data at selected depths for each station; vertical sections of temperature, salinity and potential density anomaly (sigma-theta) for the long alongshore and cross-shore sections; and maps of temperature, salinity, potential density anomaly, dynamic topography and fluorescence at selected depths
A Graphical Null Model for Scaling Biodiversity–Ecosystem Functioning Relationships
Global biodiversity is declining at rates faster than at any other point in human history. Experimental manipulations at small spatial scales have demonstrated that communities with fewer species consistently produce less biomass than higher diversity communities. Understanding the consequences of the global extinction crisis for ecosystem functioning requires understanding how local experimental results are likely to change with increasing spatial and temporal scales and from experiments to naturally assembled systems. Scaling across time and space in a changing world requires baseline predictions. Here, we provide a graphical null model for area scaling of biodiversity–ecosystem functioning relationships using observed macroecological patterns: the species–area curve and the biomass–area curve. We use species–area and biomass–area curves to predict how species richness–biomass relationships are likely to change with increasing sampling extent. We then validate these predictions with data from two naturally assembled ecosystems: a Minnesota savanna and a Panamanian tropical dry forest. Our graphical null model predicts that biodiversity–ecosystem functioning relationships are scale-dependent. However, we note two important caveats. First, our results indicate an apparent contradiction between predictions based on measurements in biodiversity–ecosystem functioning experiments and from scaling theory. When ecosystem functioning is measured as per unit area (e.g. biomass per m2), as is common in biodiversity–ecosystem functioning experiments, the slope of the biodiversity ecosystem functioning relationship should decrease with increasing scale. Alternatively, when ecosystem functioning is not measured per unit area (e.g. summed total biomass), as is common in scaling studies, the slope of the biodiversity–ecosystem functioning relationship should increase with increasing spatial scale. Second, the underlying macroecological patterns of biodiversity experiments are predictably different from some naturally assembled systems. These differences between the underlying patterns of experiments and naturally assembled systems may enable us to better understand when patterns from biodiversity–ecosystem functioning experiments will be valid in naturally assembled systems. Synthesis. This paper provides a simple graphical null model that can be extended to any relationship between biodiversity and any ecosystem functioning across space or time. Furthermore, these predictions provide crucial insights into how and when we may be able to extend results from small-scale biodiversity experiments to naturally assembled regional and global ecosystems where biodiversity is changing
Biodiversity-productivity relationships are key to nature-based climate solutions
The global impacts of biodiversity loss and climate change are interlinked, but the feedbacks between them are rarely assessed. Areas with greater tree diversity tend to be more productive, providing a greater carbon sink, and biodiversity loss could reduce these natural carbon sinks. Here, we quantify how tree and shrub species richness could affect biomass production on biome, national and regional scales. We find that GHG mitigation could help maintain tree diversity and thereby avoid a 9–39% reduction in terrestrial primary productivity across different biomes, which could otherwise occur over the next 50 years. Countries that will incur the greatest economic damages from climate change stand to benefit the most from conservation of tree diversity and primary productivity, which contribute to climate change mitigation. Our results emphasize an opportunity for a triple win for climate, biodiversity and society, and highlight that these co-benefits should be the focus of reforestation programmes
Characteristics, Distribution and Persistence of Thin Layers Over a 48 Hour Period
The biological and physical processes contributing to planktonic thin layer dynamics were examined in a multidisciplinary study conducted in East Sound, Washington, USA between June 10 and June 25, 1998. The temporal and spatial scales characteristic of thin layers were determined using a nested sampling strategy utilizing 4 major types of platforms: (1) an array of 3 moored acoustical instrument packages and 2 moored optical instrument packages that recorded distributions and intensities of thin layers; (2) additional stationary instrumentation deployed outside the array comprised of meteorological stations, wave-tide gauges, and thermistor chains; (3) a research vessel anchored 150 m outside the western edge of the array; (4) 2 mobile vessels performing basin-wide surveys to define the spatial extent of thin layers and the physical hydrography of the Sound. We observed numerous occurrences of thin layers that contained locally enhanced concentrations of material; many of the layers persisted for intervals of several hours to a few days. More than one persistent thin layer may be present at any one time, and these spatially distinct thin layers often contain distinct plankton assemblages. The results suggest that the species or populations comprising each distinct thin layer have responded to different sets of biological and/or physical processes. The existence and persistence of planktonic thin layers generates extensive biological heterogeneity in the water column and may be important in maintaining species diversity and overall community structure
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Currents and water masses of the coastal transition zone off Northern California, June to August 1988
In summer 1988, we made repeated mesoscale surveys of a grid extending 200 km offshore between
37°N and 39°N in the coastal transition zone off northern California, obtaining continuous acoustic
Doppler current profiler data and conductivity-temperature-depth data at standard stations 25 km apart
on alongshore sections 40 km apart. All surveys showed a baroclinic equatorward jet, with core
velocities of >50 cm/s at the surface decreasing to about 10 cm/s at 200m , a width of 50-75 km,
and a baroclinic transporotf about4 Sv. The core of the jet lay between the 8.6 and9 .4 m²/s²
contours of geopotential anomaly (relative to 500 dbar). Three current meter moorings, deployed at
25-km separation across the jet at the beginning of the survey sequence, provided time-series of the
velocity; throughout the 37-day deployment, at least one mooring was within the core defined by the
8.6 and9 .4 m²/s² contours. The jet flowed southwestward across the grid from late June until
mid-July 1988, when the jet axis moved offshore in the north and onshore in the southern portion of
the grid. Temperature-salinity analysis shows that jet waters can be distinguished from both the freshly
upwelled coastal waters and the offshore waters. Isopycnal maps indicate alongshore advection of
relatively fresh, cool water from farther north, as well as small-scale patchiness not resolved by our
survey grid. The baroclinic jet observed here may be continuous with the core of the California
Current off central California. The later surveys clearly showed a poleward-flowing undercurrent
adjacent to the continental slope, with core velocities up to 20 cm/s at depths of 150-250 m. Its
baroclinic transport (relative to 500 dbar) increased from 1.0 Sv between late June and
early August 1988. Within the survey grid, there was a definite onshore gradient in the characteristics
of North Pacific Intermediate Water. The subsurface waters adjacent to the continental margin were
warmer and more saline than those offshore, indicating net northward advection by the California
Undercurrent over the inshore 100 km and equatorward advection farther from shore
The cognitive organization of music knowledge: a clinical analysis
Despite much recent interest in the clinical neuroscience of music processing, the cognitive organization of music as a domain of non-verbal knowledge has been little studied. Here we addressed this issue systematically in two expert musicians with clinical diagnoses of semantic dementia and Alzheimer’s disease, in comparison with a control group of healthy expert musicians. In a series of neuropsychological experiments, we investigated associative knowledge of musical compositions (musical objects), musical emotions, musical instruments (musical sources) and music notation (musical symbols). These aspects of music knowledge were assessed in relation to musical perceptual abilities and extra-musical neuropsychological functions. The patient with semantic dementia showed relatively preserved recognition of musical compositions and musical symbols despite severely impaired recognition of musical emotions and musical instruments from sound. In contrast, the patient with Alzheimer’s disease showed impaired recognition of compositions, with somewhat better recognition of composer and musical era, and impaired comprehension of musical symbols, but normal recognition of musical emotions and musical instruments from sound. The findings suggest that music knowledge is fractionated, and superordinate musical knowledge is relatively more robust than knowledge of particular music. We propose that music constitutes a distinct domain of non-verbal knowledge but shares certain cognitive organizational features with other brain knowledge systems. Within the domain of music knowledge, dissociable cognitive mechanisms process knowledge derived from physical sources and the knowledge of abstract musical entities
Clarifying the effect of biodiversity on productivity in natural ecosystems with longitudinal data and methods for causal inference
Causal effects of biodiversity on ecosystem functions can be estimated using experimental or observational designs - designs that pose a tradeoff between drawing credible causal inferences from correlations and drawing generalizable inferences. Here, we develop a design that reduces this tradeoff and revisits the question of how plant species diversity affects productivity. Our design leverages longitudinal data from 43 grasslands in 11 countries and approaches borrowed from fields outside of ecology to draw causal inferences from observational data. Contrary to many prior studies, we estimate that increases in plot-level species richness caused productivity to decline: a 10% increase in richness decreased productivity by 2.4%, 95% CI [-4.1, -0.74]. This contradiction stems from two sources. First, prior observational studies incompletely control for confounding factors. Second, most experiments plant fewer rare and non-native species than exist in nature. Although increases in native, dominant species increased productivity, increases in rare and non-native species decreased productivity, making the average effect negative in our study. By reducing the tradeoff between experimental and observational designs, our study demonstrates how observational studies can complement prior ecological experiments and inform future ones