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1

Columbia River Plume andColumbia River Plume and California Current Ecosystem:California Current Ecosystem  

E-print Network

Columbia River Plume andColumbia River Plume and California Current Ecosystem:California Current Ecosystem: Role in Salmon ProductivityRole in Salmon Productivity NOAA FisheriesNOAA Fisheries Northwest conditions/survivalfreshwater conditions/survival ·· The coastal pelagic ecosystem is dynamic andThe coastal

2

Climate impacts on the planktonic marine ecosystem in the Southern California current  

E-print Network

funding from DOE (DE-FG02- 04ER63857), ONR (N00014-05-1-0363), NASA (funding from NSF through the California Current Ecosystem LTER (OCE-0417616), NASA (funding from DOE (DE-FG02-04ER63857), ONR (N00014-05-1-0363), NASA (

Kim, Hey-Jin

2008-01-01

3

Using expert judgment to estimate marine ecosystem vulnerability in the California Current.  

PubMed

As resource management and conservation efforts move toward multi-sector, ecosystem-based approaches, we need methods for comparing the varying responses of ecosystems to the impacts of human activities in order to prioritize management efforts, allocate limited resources, and understand cumulative effects. Given the number and variety of human activities affecting ecosystems, relatively few empirical studies are adequately comprehensive to inform these decisions. Consequently, management often turns to expert judgment for information. Drawing on methods from decision science, we offer a method for eliciting expert judgment to (1) quantitatively estimate the relative vulnerability of ecosystems to stressors, (2) help prioritize the management of stressors across multiple ecosystems, (3) evaluate how experts give weight to different criteria to characterize vulnerability of ecosystems to anthropogenic stressors, and (4) identify key knowledge gaps. We applied this method to the California Current region in order to evaluate the relative vulnerability of 19 marine ecosystems to 53 stressors associated with human activities, based on surveys from 107 experts. When judging the relative vulnerability of ecosystems to stressors, we found that experts primarily considered two criteria: the ecosystem's resistance to the stressor and the number of species or trophic levels affected. Four intertidal ecosystems (mudflat, beach, salt marsh, and rocky intertidal) were judged most vulnerable to the suite of human activities evaluated here. The highest vulnerability rankings for coastal ecosystems were invasive species, ocean acidification, sea temperature change, sea level rise, and habitat alteration from coastal engineering, while offshore ecosystems were assessed to be most vulnerable to ocean acidification, demersal destructive fishing, and shipwrecks. These results provide a quantitative, transparent, and repeatable assessment of relative vulnerability across ecosystems to any ongoing or emerging human activity. Combining these results with data on the spatial distribution and intensity of human activities provides a systematic foundation for ecosystem-based management. PMID:20666257

Teck, Sarah J; Halpern, Benjamin S; Kappel, Carrie V; Micheli, Fiorenza; Selkoe, Kimberly A; Crain, Caitlin M; Martone, Rebecca; Shearer, Christine; Arvai, Joe; Fischhoff, Baruch; Murray, Grant; Neslo, Rabin; Cooke, Roger

2010-07-01

4

Screening California Current fishery management scenarios using the Atlantis end-to-end ecosystem model  

NASA Astrophysics Data System (ADS)

End-to-end marine ecosystem models link climate and oceanography to the food web and human activities. These models can be used as forecasting tools, to strategically evaluate management options and to support ecosystem-based management. Here we report the results of such forecasts in the California Current, using an Atlantis end-to-end model. We worked collaboratively with fishery managers at NOAAs regional offices and staff at the National Marine Sanctuaries (NMS) to explore the impact of fishery policies on management objectives at different spatial scales, from single Marine Sanctuaries to the entire Northern California Current. In addition to examining Status Quo management, we explored the consequences of several gear switching and spatial management scenarios. Of the scenarios that involved large scale management changes, no single scenario maximized all performance metrics. Any policy choice would involve trade-offs between stakeholder groups and policy goals. For example, a coast-wide 25% gear shift from trawl to pot or longline appeared to be one possible compromise between an increase in spatial management (which sacrificed revenue) and scenarios such as the one consolidating bottom impacts to deeper areas (which did not perform substantially differently from Status Quo). Judged on a coast-wide scale, most of the scenarios that involved minor or local management changes (e.g. within Monterey Bay NMS only) yielded results similar to Status Quo. When impacts did occur in these cases, they often involved local interactions that were difficult to predict a priori based solely on fishing patterns. However, judged on the local scale, deviation from Status Quo did emerge, particularly for metrics related to stationary species or variables (i.e. habitat and local metrics of landed value or bycatch). We also found that isolated management actions within Monterey Bay NMS would cause local fishers to pay a cost for conservation, in terms of reductions in landed value. However, this cost was minimal when local conservation actions were part of a concerted coast-wide plan. The simulations demonstrate the utility of using the Atlantis end-to-end ecosystem model within NOAAs Integrated Ecosystem Assessment, by illustrating an end-to-end modeling tool that allows consideration of multiple management alternatives that are relevant to numerous state, federal and private interests.

Kaplan, Isaac C.; Horne, Peter J.; Levin, Phillip S.

2012-09-01

5

Enhanced nutrient supply to the California Current Ecosystem with global warming and increased stratification in an earth system model  

Microsoft Academic Search

A leading hypothesis relating productivity with climate variability in the California Current Ecosystem (CCE) describes an alternation between warmer, well-stratified periods of low productivity and cooler periods of high productivity. This empirical relationship suggests that productivity will decline with global warming. Here, we explore the response of productivity to future climate change in the CCE using an earth system model.

Ryan R. Rykaczewski; John P. Dunne

2010-01-01

6

Declining Abundance of Beaked Whales (Family Ziphiidae) in the California Current Large Marine Ecosystem  

PubMed Central

Beaked whales are among the most diverse yet least understood groups of marine mammals. A diverse set of mostly anthropogenic threats necessitates improvement in our ability to assess population status for this cryptic group. The Southwest Fisheries Science Center (NOAA) conducted six ship line-transect cetacean abundance surveys in the California Current off the contiguous western United States between 1991 and 2008. We used a Bayesian hidden-process modeling approach to estimate abundance and population trends of beaked whales using sightings data from these surveys. We also compiled records of beaked whale stranding events (3 genera, at least 8 species) on adjacent beaches from 1900 to 2012, to help assess population status of beaked whales in the northern part of the California Current. Bayesian posterior summaries for trend parameters provide strong evidence of declining beaked whale abundance in the study area. The probability of negative trend for Cuvier's beaked whale (Ziphius cavirostris) during 19912008 was 0.84, with 1991 and 2008 estimates of 10771 (CV?=?0.51) and ?7550 (CV?=?0.55), respectively. The probability of decline for Mesoplodon spp. (pooled across species) was 0.96, with 1991 and 2008 estimates of 2206 (CV?=?0.46) and 811 (CV?=?0.65). The mean posterior estimates for average rate of decline were 2.9% and 7.0% per year. There was no evidence of abundance trend for Baird's beaked whale (Berardius bairdii), for which annual abundance estimates in the survey area ranged from ?900 to 1300 (CV?1.3). Stranding data were consistent with the survey results. Causes of apparent declines are unknown. Direct impacts of fisheries (bycatch) can be ruled out, but impacts of anthropogenic sound (e.g., naval active sonar) and ecosystem change are plausible hypotheses that merit investigation. PMID:23341907

Moore, Jeffrey E.; Barlow, Jay P.

2013-01-01

7

Do inverse ecosystem models accurately reconstruct plankton trophic flows? Comparing two solution methods using field data from the California Current  

NASA Astrophysics Data System (ADS)

Despite the increasing use of linear inverse modeling techniques to elucidate fluxes in undersampled marine ecosystems, the accuracy with which they estimate food web flows has not been resolved. New Markov Chain Monte Carlo (MCMC) solution methods have also called into question the biases of the commonly used L2 minimum norm (L 2MN) solution technique. Here, we test the abilities of MCMC and L 2MN methods to recover field-measured ecosystem rates that are sequentially excluded from the model input. For data, we use experimental measurements from process cruises of the California Current Ecosystem (CCE-LTER) Program that include rate estimates of phytoplankton and bacterial production, micro- and mesozooplankton grazing, and carbon export from eight study sites varying from rich coastal upwelling to offshore oligotrophic conditions. Both the MCMC and L 2MN methods predicted well-constrained rates of protozoan and mesozooplankton grazing with reasonable accuracy, but the MCMC method overestimated primary production. The MCMC method more accurately predicted the poorly constrained rate of vertical carbon export than the L 2MN method, which consistently overestimated export. Results involving DOC and bacterial production were equivocal. Overall, when primary production is provided as model input, the MCMC method gives a robust depiction of ecosystem processes. Uncertainty in inverse ecosystem models is large and arises primarily from solution under-determinacy. We thus suggest that experimental programs focusing on food web fluxes expand the range of experimental measurements to include the nature and fate of detrital pools, which play large roles in the model.

Stukel, Michael R.; Landry, Michael R.; Ohman, Mark D.; Goericke, Ralf; Samo, Ty; Benitez-Nelson, Claudia R.

2012-03-01

8

Top-down modeling and bottom-up dynamics: Linking a fisheries-based ecosystem model with climate hypotheses in the Northern California Current  

Microsoft Academic Search

In this paper we present results from dynamic simulations of the Northern California Current ecosystem, based on historical estimates of fishing mortality, relative fishing effort, and climate forcing. Climate can affect ecosystem productivity and dynamics both from the bottom-up (through short- and long-term variability in primary and secondary production) as well as from the top-down (through variability in the abundance

J. C. Field; R. C. Francis; K. Aydin

2006-01-01

9

Ecosystem size structure response to 21st century climate projection: large fish abundance decreases in the central North Pacific and increases in the California Current.  

PubMed

Output from an earth system model is paired with a size-based food web model to investigate the effects of climate change on the abundance of large fish over the 21st century. The earth system model, forced by the Intergovernmental Panel on Climate Change (IPCC) Special report on emission scenario A2, combines a coupled climate model with a biogeochemical model including major nutrients, three phytoplankton functional groups, and zooplankton grazing. The size-based food web model includes linkages between two size-structured pelagic communities: primary producers and consumers. Our investigation focuses on seven sites in the North Pacific, each highlighting a specific aspect of projected climate change, and includes top-down ecosystem depletion through fishing. We project declines in large fish abundance ranging from 0 to 75.8% in the central North Pacific and increases of up to 43.0% in the California Current (CC) region over the 21st century in response to change in phytoplankton size structure and direct physiological effects. We find that fish abundance is especially sensitive to projected changes in large phytoplankton density and our model projects changes in the abundance of large fish being of the same order of magnitude as changes in the abundance of large phytoplankton. Thus, studies that address only climate-induced impacts to primary production without including changes to phytoplankton size structure may not adequately project ecosystem responses. PMID:23504830

Woodworth-Jefcoats, Phoebe A; Polovina, Jeffrey J; Dunne, John P; Blanchard, Julia L

2013-03-01

10

The Development of Automated Detection Techniques for Passive Acoustic Monitoring as a Tool for Studying Beaked Whale Distribution and Habitat Preferences in the California Current Ecosystem  

NASA Astrophysics Data System (ADS)

The objectives of this research were to test available automated detection methods for passive acoustic monitoring and integrate the best available method into standard marine mammal monitoring protocols for ship based surveys. The goal of the first chapter was to evaluate the performance and utility of PAMGUARD 1.0 Core software for use in automated detection of marine mammal acoustic signals during towed array surveys. Three different detector configurations of PAMGUARD were compared. These automated detection algorithms were evaluated by comparing them to the results of manual detections made by an experienced bio-acoustician (author TMY). This study provides the first detailed comparisons of PAMGUARD automated detection algorithms to manual detection methods. The results of these comparisons clearly illustrate the utility of automated detection methods for odontocete species. Results of this work showed that the majority of whistles and click events can be reliably detected using PAMGUARD software. The second chapter moves beyond automated detection to examine and test automated classification algorithms for beaked whale species. Beaked whales are notoriously elusive and difficult to study, especially using visual survey methods. The purpose of the second chapter was to test, validate, and compare algorithms for detection of beaked whales in acoustic line-transect survey data. Using data collected at sea from the PAMGUARD classifier developed in Chapter 2 it was possible to measure the clicks from visually verified Baird's beaked whale encounters and use this data to develop classifiers that could discriminate Baird's beaked whales from other beaked whale species in future work. Echolocation clicks from Baird's beaked whales, Berardius bairdii, were recorded during combined visual and acoustic shipboard surveys of cetacean populations in the California Current Ecosystem (CCE) and with autonomous, long-term recorders at four different sites in the Southern California Bight (SCB). The preliminary measurement of the visually validated Baird's beaked whale echolocation signals recorded from the ship-based towed array were used as a basis for identifying Baird's signals in the seafloor-mounted autonomous recorder data. The passive acoustic detection algorithms for beaked whales developed using data from Chapters 2 and 3 were field tested during a three year period to test the reliability of acoustic beaked whale monitoring techniques and to use these methods to describe beaked whale habitat in the SCB. In 2009 and 2010, PAM methods using towed hydrophone arrays were tested. These methods proved highly effective for real-time detection of beaked whales in the SCB and were subsequently implemented in 2011 to successfully detect and track beaked whales during the ongoing Southern California Behavioral Response Study (SOCAL-BRS). The final step in this research was to utilize the passive acoustic detection techniques developed herin to predictively model beaked whale habitat use and preferences in the CCE. This chapter uses a multifaceted approach to model beaked whale encounter rates in the CCE. Beaked whale acoustic encounters are utilized to inform Generalized Additive Models (GAMs) of encounter rate for beaked whales in the CCE and compare these to visual based models. Acoustic and visual based models were independently developed for a small beaked whale group and Baird's beaked whales. Two models were evaluated for visual and acoustic encounters, one that also included Beaufort sea state as a predictor variable in addition to those listed and one that did not include Beaufort sea state. (Abstract shortened by UMI.)

Yack, Tina M.

11

Title: EOY Satellite-Derived Climatologies: The California Current Large Marine Ecosystem--Surface Forcing and Response Along Western North America  

E-print Network

PROJECT 2a Title: EOY Satellite-Derived Climatologies: The California Current Large Marine-Scale climatological fields of surface forcing (wind stress) and surface ocean response (sea surface temperature [SST section. Satellite Climatology: This report builds on last year's report in a somewhat cumulative fashion

Kurapov, Alexander

12

California Water Policy Seminar Series Reconciling Ecosystem And Economy  

E-print Network

California Water Policy Seminar Series Reconciling Ecosystem And Economy Winter 2014 Mondays, 4 graduate seminar on water policy as ECI 298, contact Jay Lund; as Ecology 290, contact Peter Moyle. Law, Association of California Water Agencies; Richard Howitt, UC Davis Department of Agricultural & Resource

Ferrara, Katherine W.

13

Navigating Fragmented Ocean Law in the California Current: Tools to Identify and Measure Gaps and Overlaps for Ecosystem-Based Management  

E-print Network

ecosystem model matrix into interaction types corresponding with the categories of Source, Cause, Effect, Impact, and Ecological Impact, and Humanecosystem matrix between categories of Source and Cause. Source Cause Effect Impact Eco Impact Human

Ekstrom, Julia A.

2008-01-01

14

Predictability of the California Current System  

NASA Technical Reports Server (NTRS)

The physical and biological oceanography of the Southern California Bight (SCB), a highly productive subregion of the California Current System (CCS) that extends from Point Conception, California, south to Ensenada, Mexico, continues to be extensively studied. For example, the California Cooperative Oceanic Fisheries Investigations (CalCOFI) program has sampled this region for over 50 years, providing an unparalleled time series of physical and biological data. However, our understanding of what physical processes control the large-scale and mesoscale variations in these properties is incomplete. In particular, the non-synoptic and relatively coarse spatial sampling (70km) of the hydrographic grid does not completely resolve the mesoscale eddy field (Figure 1a). Moreover, these unresolved physical variations exert a dominant influence on the evolution of the ecosystem. In recent years, additional datasets that partially sample the SCB have become available. Acoustic Doppler Current Profiler (ADCP) measurements, which now sample upper-ocean velocity between stations, and sea level observations along TOPEX tracks give a more complete picture of the mesoscale variability. However, both TOPEX and ADCP are well-sampled only along the cruise or orbit tracks and coarsely sampled in time and between tracks. Surface Lagrangian drifters also sample the region, although irregularly in time and space. SeaWiFS provides estimates of upper-ocean chlorophyll-a (chl-alpha), usually giving nearly complete coverage for week-long intervals, depending on cloud coverage. Historical ocean color data from the Coastal Zone Color Scanner (CZCS) has been used extensively to determine phytoplankton patterns and variability, characterize the primary production across the SCB coastal fronts, and describe the seasonal and interannual variability in pigment concentrations. As in CalCOFI, these studies described much of the observed structures and their variability over relatively large space and time scales.

Miller, Arthur J.; Chereskin, T.; Cornuelle, B. D.; Niiler, P. P.; Moisan, J. R.; Lindstrom, Eric (Technical Monitor)

2001-01-01

15

Avian Conservation Practices Strengthen Ecosystem Services in California Vineyards  

Microsoft Academic Search

Insectivorous Western Bluebirds (Sialia mexicana) occupy vineyard nest boxes established by California winegrape growers who want to encourage avian conservation. Experimentally, the provision of available nest sites serves as an alternative to exclosure methods for isolating the potential ecosystem services provided by foraging birds. We compared the abundance and species richness of avian foragers and removal rates of sentinel prey

Julie A. Jedlicka; Russell Greenberg; Deborah K. Letourneau

2011-01-01

16

Assessment of Potential Aquatic Herbicide Impacts to California Aquatic Ecosystems  

E-print Network

Assessment of Potential Aquatic Herbicide Impacts to California Aquatic Ecosystems Geoffrey S and implement a 3-year monitoring program to determine the potential environmental impacts of aquatic herbicide association with herbicide appli- cations. Applications of acrolein, copper sulfate, chelated copper, diquat

17

Fog Water and Ecosystem Function: Heterogeneity in a California  

E-print Network

Fog Water and Ecosystem Function: Heterogeneity in a California Redwood Forest Holly A. Ewing,1 Biology, University of Connecticut, 75 N. Eagleville Road, Storrs, Connecticut 06269, USA ABSTRACT Fog and nitrogen (N) fluxes from hori- zontally moving fog and vertically delivered rain as well as redwood tree

Berkowitz, Alan R.

18

Future scenarios of impacts to ecosystem services on California rangelands  

USGS Publications Warehouse

The 18 million acres of rangelands in the Central Valley of California provide multiple benefits or ecosystem services to peopleincluding wildlife habitat, water supply, open space, recreation, and cultural resources. Most of this land is privately owned and managed for livestock production. These rangelands are vulnerable to land-use conversion and climate change. To help resource managers assess the impacts of land-use change and climate change, U.S. Geological Survey scientists and their cooperators developed scenarios to quantify and map changes to three main rangeland ecosystem serviceswildlife habitat, water supply, and carbon sequestration. Project results will help prioritize strategies to conserve these rangelands and the ecosystem services that they provide.

Byrd, Kristin; Alvarez, Pelayo; Flint, Lorraine; Flint, Alan

2014-01-01

19

Whither the Rangeland?: Protection and conversion in California's Rangeland ecosystems.  

PubMed

Land use change in rangeland ecosystems is pervasive throughout the western United States with widespread ecological, social and economic implications. In California, rangeland habitats have high biodiversity value, provide significant habitat connectivity and form the foundation for a number of ecosystem services. To comprehensively assess the conservation status of these habitats, we analyzed the extent and drivers of habitat loss and the degree of protection against future loss across a 13.5 M ha study area in California. We analyzed rangeland conversion between 1984 and 2008 using time series GIS data and classified resulting land uses with aerial imagery. In total, over 195,000 hectares of rangeland habitats were converted during this period. The majority of conversions were to residential and associated commercial development (49% of the area converted), but agricultural intensification was surprisingly extensive and diverse (40% across six categories). Voluntary enrollment in an agricultural tax incentive program provided widespread protection from residential and commercial conversions across 37% of the remaining rangeland habitat extent (7.5 M ha), though this program did not protect rangeland from conversion to more intensive agricultural uses. Additionally, 24% of the remaining rangeland was protected by private conservation organizations or public agencies through land or easement ownership while 38% had no protection status at all. By developing a spatial method to analyze the drivers of loss and patterns of protection, this study demonstrates a novel approach to prioritize conservation strategies and implementation locations to avert habitat conversion. We propose that this approach can be used in other ecosystem types, and can serve as a regional conservation baseline assessment to focus strategies to effect widespread, cost-effective conservation solutions. PMID:25141171

Cameron, D Richard; Marty, Jaymee; Holland, Robert F

2014-01-01

20

Avian conservation practices strengthen ecosystem services in California vineyards.  

PubMed

Insectivorous Western Bluebirds (Sialia mexicana) occupy vineyard nest boxes established by California winegrape growers who want to encourage avian conservation. Experimentally, the provision of available nest sites serves as an alternative to exclosure methods for isolating the potential ecosystem services provided by foraging birds. We compared the abundance and species richness of avian foragers and removal rates of sentinel prey in treatments with songbird nest boxes and controls without nest boxes. The average species richness of avian insectivores increased by over 50 percent compared to controls. Insectivorous bird density nearly quadrupled, primarily due to a tenfold increase in Western Bluebird abundance. In contrast, there was no significant difference in the abundance of omnivorous or granivorous bird species some of which opportunistically forage on grapes. In a sentinel prey experiment, 2.4 times more live beet armyworms (Spodoptera exigua) were removed in the nest box treatment than in the control. As an estimate of the maximum foraging services provided by insectivorous birds, we found that larval removal rates measured immediately below occupied boxes averaged 3.5 times greater than in the control. Consequently the presence of Western Bluebirds in vineyard nest boxes strengthened ecosystem services to winegrape growers, illustrating a benefit of agroecological conservation practices. Predator addition and sentinel prey experiments lack some disadvantages of predator exclusion experiments and were robust methodologies for detecting ecosystem services. PMID:22096555

Jedlicka, Julie A; Greenberg, Russell; Letourneau, Deborah K

2011-01-01

21

Avian Conservation Practices Strengthen Ecosystem Services in California Vineyards  

PubMed Central

Insectivorous Western Bluebirds (Sialia mexicana) occupy vineyard nest boxes established by California winegrape growers who want to encourage avian conservation. Experimentally, the provision of available nest sites serves as an alternative to exclosure methods for isolating the potential ecosystem services provided by foraging birds. We compared the abundance and species richness of avian foragers and removal rates of sentinel prey in treatments with songbird nest boxes and controls without nest boxes. The average species richness of avian insectivores increased by over 50 percent compared to controls. Insectivorous bird density nearly quadrupled, primarily due to a tenfold increase in Western Bluebird abundance. In contrast, there was no significant difference in the abundance of omnivorous or granivorous bird species some of which opportunistically forage on grapes. In a sentinel prey experiment, 2.4 times more live beet armyworms (Spodoptera exigua) were removed in the nest box treatment than in the control. As an estimate of the maximum foraging services provided by insectivorous birds, we found that larval removal rates measured immediately below occupied boxes averaged 3.5 times greater than in the control. Consequently the presence of Western Bluebirds in vineyard nest boxes strengthened ecosystem services to winegrape growers, illustrating a benefit of agroecological conservation practices. Predator addition and sentinel prey experiments lack some disadvantages of predator exclusion experiments and were robust methodologies for detecting ecosystem services. PMID:22096555

Jedlicka, Julie A.; Greenberg, Russell; Letourneau, Deborah K.

2011-01-01

22

Assessing Nitrate Deposition in Southern California Ecosystems using ?17O.  

NASA Astrophysics Data System (ADS)

Assessing the impact of atmospheric deposition of fixed nitrogen on local, regional, and global biogeochemical cycles has received much attention in recent years. Local and regional ecosystems can suffer from eutrophication and shrinking biodiversity from the increased nitrogen flux, in addition to degradation associated with acid rain (an increasing proportion of which is as HNO3 ). On a global scale, the effect of nitrogen fertilization on CO2 uptake rates is one of the biggest unknowns in global warming research. This renewed interest has led to new attempts to utilize current, and in the development of new, analytical techniques in order to better understand the source, sink and transport mechanisms of atmospheric nitrogen deposition. Stable isotopes of nitrogen and oxygen have been used to trace atmospheric nitrate through the biogeochemical system. 15N ratios have been problematic due to the lack of large fractionations and an overlap of 15N ratios between sources. Initial studies of 18O ratios showed promise due to the large enrichment (60 ) in atmospheric nitrate. However, subsequent studies showed an ? 18O spread of 25 - 80 and have made quantitative analysis of mixing reservoirs difficult. Atmospheric nitrates have now been measured and have been found to have a large MIF; ?17O ~ 25 and a small range +/- 4 . The large variations in ? 18O that may result from post depositional fractionations associated with soil migration and microbial utilization are mass dependent processes and leave the ?17O unaffected. It can therefore be used as a conservative trace of atmospheric nitrate deposition. A preliminary study of the southern California coastal sage scrub and alpine forest habitat examined the variability and detect- ability of nitrate deposition using ?17O. Nitrate from atmospheric aerosols, nitric acid vapor, and wet deposition all had ?17O values in the same range as other studies: 25 . Surface soils showed large deposition contributions to total N. Soil lysimeter measurements revealed large ? 18O depletions indicating large fractionation factors from soil uptake. Stream water also exhibited low ? 18O values, but significant ?17O values 0-6 indicating atmospheric contributions of 0 to 20 %. Observations of low ? 18O (10 ) in streams where the ?17O indicate in excess of 20 % deposition suggest a reevaluation of studies which used ? 18O as a tracer of nitrate deposition.

Hernandez, L.; Michalski, G.; Meixner, T.; Fenn, M.; Thiemens, M. H.

2002-12-01

23

Satellite streamfunction analysis for the California current  

E-print Network

velocity field from infrared satellite measurements are related to the cloud tracking algorithm developed by meteorol- ogists (Vastano and Borders, 1984; Vastano et al. , 1985; Vastano and Raid, 1985). This interactive image processing algorithm requires... and the iterative procedure see Wanstrath (1975). 20 III. APPLICATION A. Satellite-Derived Sea Surface Flow The present study uses NIMBUS-7 CZCS visible and infrared images in the California Current taken during 7 snd 8 July 1981. Image processing was carried...

Arango, Hernan Guillermo

2012-06-07

24

Measuring Tsunami Current Velocities on Californias North Coast  

NASA Astrophysics Data System (ADS)

The Northern California coast is particularly susceptible to tsunami damage. Thirty-one tsunamis have been recorded since 1933 when the first tide gauge was installed at Citizens Dock in Crescent City, California and four have caused damage. In November 2006, a magnitude 8.3 earthquake in the Kuril Islands generated a tsunami that caused over $20 million in damages and replacement costs to the Crescent City small boat basin. The 2006 tsunami did not flood any areas above the normal high tide; very strong currents produced as the tsunami surged in and out of the small boat basin caused all of the damage. The Harbor Master and commercial fishermen in the area estimated the peak currents near the mouth of the small boat basin at 12 to 15 knots or 6 to 8 m/sec. MOST numerical modeling of the 2006 currents in Crescent City gives peak velocities in the 2-3 m/sec range. We have initiated a pilot project to directly measure current velocities produced by moderate tsunamis such as the 2006 event. In spring of 2009 we acquired a Nortek Aquadopp 600 kHz acoustic 2-D current profiler through a donation from the Pacific Gas and Electric Company to measure currents in Humboldt Bay, located 100 km south of Crescent City. The manufacturer specifies the current meter can measure currents up to 10 m/sec. In a preliminary deployment at the Fairhaven dock inside Humboldt Bay in May 2009, we measured current velocities of 1.5 m/sec caused by the daily tidal fluctuation with a 1 minute sampling rate. Our primary goal is to model control and data telemetry of this current meter after NOAAs tsunami-ready tide gages, in collaboration with NOAA personnel at PMEL and CO-OPS. We also intend to make available real-time current measurements online for the local maritime community. In this poster, we present preliminary results from the current meter and discuss deployment and telecommunication considerations. While some interference is present in the closest range bins, the system measures currents in the nearby navigational channel that compare favorably to NOAA tidal predictions at a nearby location. Once the deployment and telemetry issues have been resolved at the Humboldt Bay site, we will be deploying two additional instruments in Crescent City.

Crawford, G. B.; Dengler, L. A.; Montoya, J.

2009-12-01

25

Climate Change in Mountain Ecosystems Areas of Current Research  

E-print Network

Climate Change in Mountain Ecosystems Areas of Current Research · Glacier Research · Snow Initiative Glacier Research A Focus on Mountain Ecosystems Climate change is widely acknowledged to be having in the western U.S. and the Northern Rockies in particular are highly sensitive to climate change. In fact

26

Ecosystem Change in California Grasslands: Impacts of Species Invasion  

NASA Astrophysics Data System (ADS)

Grassland ecosystems of California have undergone dramatic changes, resulting in the almost complete replacement of native perennial grasses by non-native annuals across millions of hectares of grassland habitat. Our research investigates the effects of this community shift on carbon, water and energy cycles at two sites in northern coastal California. Our goal was to understand how changes to Californias grasslands have affected climate through 1. shifting the balance of carbon storage between terrestrial stocks and the atmosphere, and 2. altering the water and energy regimes that heat or cool the earth's surface. To compare the processes that govern material exchange before and after annual grass invasion, we made use of sites where native vegetation is found adjacent to locations that have undergone non-native invasion. In plots of each vegetation type, we monitored whole plant productivity, root and litter decay rates and soil respiration, as well as soil climatic controls on these processes. At one site, we also measured surface albedo and the components of the surface energy balance in each grass community, using the surface renewal method. Although seemingly subtle, the shift in California grassland communities from native perennial to non-native annual grass dominance has had profound consequences for ecosystem biogeochemical, radiative and hydrological cycles. Soil carbon storage was found to be significantly greater in native perennial grass communities. Across both study sites, we found that non-native grass invasion has resulted in the transfer of from 3 to 6 tons of carbon per hectare from the soil to the atmosphere, dependent on site and species. A soil density fractionation and a radiocarbon analysis also revealed the carbon to be more recalcitrant in native grass dominated locations. The primary plant traits that help explain why soil carbon losses follow annual grass invasion are: 1. differences between annual and perennial grasses in above/ belowground allocation, 2. differences in growth plasticity in response to inter-annual precipitation variability, and 3. the effect of differences in rooting depth and aboveground morphology on soil moisture content and soil respiration. Over the years 2004-2006, we found energy partitioning into latent and sensible heat flux to be similar among annual and perennial grass communities during periods of sufficient soil moisture availability. When water becomes scarce in the late spring, however, and annual grasses die, the ratio of latent to sensible heat loss is reduced in annual grass communities relative to perennials. The deep roots of perennial grasses prolong the period over which transpiration occurs. We also found that albedo differs year-round between perennial and annual grasses, tracking differences in grass phenology. Albedo differences are at a maximum during the summer and autumn months. At this time, the lower albedo in non-native annual communities can raise near surface temperatures up to 6 oC midday relative to native perennials.

Koteen, L. E.; Harte, J.; Baldocchi, D. D.

2009-12-01

27

Persistence of chlorinated hydrocarbon contamination in a California marine ecosystem  

SciTech Connect

Despite major reductions in the dominant DDT and polychlorinated biphenyls (PCB) input off Los Angeles (California, U.S.A.) in the early 1970s, the levels of these pollutants decreased only slightly from 1972 to 1975 both in surficial bottom sediments and in a flatfish bioindicator (Dover sole, Microstomus pacificus) collected near the submarine outfall. Concentrations of these pollutants in the soft tissues of the mussel Mytilus californianus, collected intertidally well inshore of the highly contaminated bottom sediments, followed much more closely the decreases in the outfall discharges. These observations suggest that contaminated sediments on the seafloor were the principal (although not necessarily direct) cause of the relatively high and persistent concentrations of DDT and PCB residues in tissues. The study indicated that residues of the higher-molecular-weight chlorinated hydrocarbons, such as DDT and PCB, can be highly persistent once released to coastal marine ecosystems and that their accumulation in surficial bottom sediments is the most likely cause of this persistence observed in the biota of the discharge zone.

Young, D.R.; Gossett, R.W.; Heesen, T.C.

1989-01-01

28

Responses of soil respiration to elevated CO[sub 2] in two California grassland ecosystems  

SciTech Connect

Estimates of soil respiration (SR) in current and elevated CO[sub 2] are critical for predicting future global carbon budgets. We measured SR in two California grassland ecosystems (sandstone and serpentine) growing at ambient and ambient+350 ppm CO[sub 2]. SR was higher in elevated CO[sub 2] for both ecosystems in the field, but differences were not significant. At peak plant growth, SR was approximately 6 [mu]mol m[sup [minus]2]s[sup [minus]1] in elevated CO[sub 2] and 5 [mu]mol m[sup [minus]2] s[sup [minus]1] in ambient CO[sub 2] for both ecosystems. We also examined soil respiration in monocultures of 7 grassland species grown in microecosystems (10-cm diameter by 1-m deep tubes). SR was approximately 2 [mu]mol m[sup [minus]2]s[sup [minus]1] for Plantago, Bromus, Hemizona, and Calycadenia and 7 [minus] 8 [mu]mol m[sup [minus]2]s[sup [minus]2] for Lolium, Avena, and Vulpia. Elevated CO[sub 2] significantly increased soil respiration by 20-30% in Bromus, Hemizonia and Lolium monocultures. SR was significantly correlated with total plant biomass as averaged across all species.

Luo, Y.; Jackson, R.B.; Field, C.B.; Mooney, H.A. (Stanford Univ., CA (United States))

1994-06-01

29

Predator-Driven Nutrient Recycling in California Stream Ecosystems  

PubMed Central

Nutrient recycling by consumers in streams can influence ecosystem nutrient availability and the assemblage and growth of photoautotrophs. Stream fishes can play a large role in nutrient recycling, but contributions by other vertebrates to overall recycling rates remain poorly studied. In tributaries of the Pacific Northwest, coastal giant salamanders (Dicamptodon tenebrosus) occur at high densities alongside steelhead trout (Oncorhynchus mykiss) and are top aquatic predators. We surveyed the density and body size distributions of D. tenebrosus and O. mykiss in a California tributary stream, combined with a field study to determine mass-specific excretion rates of ammonium (N) and total dissolved phosphorus (P) for D. tenebrosus. We estimated O. mykiss excretion rates (N, P) by bioenergetics using field-collected data on the nutrient composition of O. mykiss diets from the same system. Despite lower abundance, D. tenebrosus biomass was 2.5 times higher than O. mykiss. Mass-specific excretion summed over 170 m of stream revealed that O. mykiss recycle 1.7 times more N, and 1.2 times more P than D. tenebrosus, and had a higher N:P ratio (8.7) than that of D. tenebrosus (6.0), or the two species combined (7.5). Through simulated trade-offs in biomass, we estimate that shifts from salamander biomass toward fish biomass have the potential to ease nutrient limitation in forested tributary streams. These results suggest that natural and anthropogenic heterogeneity in the relative abundance of these vertebrates and variation in the uptake rates across river networks can affect broad-scale patterns of nutrient limitation. PMID:23520520

Munshaw, Robin G.; Palen, Wendy J.; Courcelles, Danielle M.; Finlay, Jacques C.

2013-01-01

30

Evaluating Ecosystem Services Provided by Non-Native Species: An Experimental Test in California Grasslands  

PubMed Central

The concept of ecosystem services the benefits that nature provides to human's society has gained increasing attention over the past decade. Increasing global abiotic and biotic change, including species invasions, is threatening the secure delivery of these ecosystem services. Efficient evaluation methods of ecosystem services are urgently needed to improve our ability to determine management strategies and restoration goals in face of these new emerging ecosystems. Considering a range of multiple ecosystem functions may be a useful way to determine such strategies. We tested this framework experimentally in California grasslands, where large shifts in species composition have occurred since the late 1700's. We compared a suite of ecosystem functions within one historic native and two non-native species assemblages under different grazing intensities to address how different species assemblages vary in provisioning, regulatory and supporting ecosystem services. Forage production was reduced in one non-native assemblage (medusahead). Cultural ecosystem services, such as native species diversity, were inherently lower in both non-native assemblages, whereas most other services were maintained across grazing intensities. All systems provided similar ecosystem services under the highest grazing intensity treatment, which simulated unsustainable grazing intensity. We suggest that applying a more comprehensive ecosystem framework that considers multiple ecosystem services to evaluate new emerging ecosystems is a valuable tool to determine management goals and how to intervene in a changing ecosystem. PMID:25222028

Stein, Claudia; Hallett, Lauren M.; Harpole, W. Stanley; Suding, Katharine N.

2014-01-01

31

Evaluating ecosystem services provided by non-native species: an experimental test in California grasslands.  

PubMed

The concept of ecosystem services--the benefits that nature provides to human's society--has gained increasing attention over the past decade. Increasing global abiotic and biotic change, including species invasions, is threatening the secure delivery of these ecosystem services. Efficient evaluation methods of ecosystem services are urgently needed to improve our ability to determine management strategies and restoration goals in face of these new emerging ecosystems. Considering a range of multiple ecosystem functions may be a useful way to determine such strategies. We tested this framework experimentally in California grasslands, where large shifts in species composition have occurred since the late 1700's. We compared a suite of ecosystem functions within one historic native and two non-native species assemblages under different grazing intensities to address how different species assemblages vary in provisioning, regulatory and supporting ecosystem services. Forage production was reduced in one non-native assemblage (medusahead). Cultural ecosystem services, such as native species diversity, were inherently lower in both non-native assemblages, whereas most other services were maintained across grazing intensities. All systems provided similar ecosystem services under the highest grazing intensity treatment, which simulated unsustainable grazing intensity. We suggest that applying a more comprehensive ecosystem framework that considers multiple ecosystem services to evaluate new emerging ecosystems is a valuable tool to determine management goals and how to intervene in a changing ecosystem. PMID:25222028

Stein, Claudia; Hallett, Lauren M; Harpole, W Stanley; Suding, Katharine N

2014-01-01

32

STATE OF THE CALIFORNIA CURRENT CalCOFI Rep., Vol. 52, 2011  

E-print Network

HomPsoN Farallon institute for Advanced Ecosystem research Petaluma, cA 94952 joHN l. lArGiEr, cHris HAllE to be unfolding over longer time scales (e.g.,freshening of upper water column and trends in nitrate and oxygen concentrations). in contrast, the northern california current has exhibited much more dramatic short-term changes

33

Sudden Oak Death: Endangering California and Oregon Forest Ecosystems  

Microsoft Academic Search

Sudden oak death is a new disease affecting tanoak (Lithocarpus densiflora) and oaks (Quercus spp) in California and Oregon, caused by the recently described pathogen Phytophthora ramorum. It has reached epi-demic proportions in several counties in central California, leading to the death of tens of thousands of trees. In addition to oaks and tanoak, P ramorum has been found in

David M. Rizzo; Matteo Garbelotto

2003-01-01

34

Fog in the California redwood forest: ecosystem inputs and use by plants  

Microsoft Academic Search

Fog has been viewed as an important source of moisture in many coastal ecosystems, yet its importance for the plants which\\u000a inhabit these ecosystems is virtually unknown. Here, I report the results of a 3-year investigation of fog inputs and the\\u000a use of fog water by plants inhabiting the heavily fog inundated coastal redwood (Sequoia sempervirens) forests of northern California.

T. E. Dawson

1998-01-01

35

Salmonella spp., Vibrio spp., Clostridium perfringens , and Plesiomonas shigelloides in Marine and Freshwater Invertebrates from Coastal California Ecosystems  

Microsoft Academic Search

The coastal ecosystems of California are highly utilized by humans and animals, but the ecology of fecal bacteria at the landsea interface is not well understood. This study evaluated the distribution of potentially pathogenic bacteria in invertebrates from linked marine, estuarine, and freshwater ecosystems in central California. A variety of filter-feeding clams, mussels, worms, and crab tissues were selectively cultured

W. A. Miller; M. A. Miller; I. A. Gardner; E. R. Atwill; B. A. Byrne; S. Jang; M. Harris; J. Ames; D. Jessup; D. Paradies; K. Worcester; A. Melli; P. A. Conrad

2006-01-01

36

Assessment of Potential Aquatic Herbicide Impacts to California Aquatic Ecosystems  

Microsoft Academic Search

A series of legal decisions culminated in 2002 with the California State Water Resources Control Board funding the San Francisco\\u000a Estuary Institute to develop and implement a 3-year monitoring program to determine the potential environmental impacts of\\u000a aquatic herbicide applications. The monitoring program was intended to investigate the behavior of all aquatic pesticides\\u000a in use in California, to determine potential

Geoffrey S. Siemering; Jennifer D. Hayworth; Ben K. Greenfield

2008-01-01

37

Effects of drought stress on microbial dynamics in seasonally dry California ecosystems  

NASA Astrophysics Data System (ADS)

One of the key environmental factors controlling microbial activity is moisture. This water limitation is particularly strong in semi-arid and arid ecosystems such as those found along California's coast and interior range-lands. Cool, wet winters separated by long, dry summers present some the most challenging conditions for microbial survival and growth. Infrequent pulses of precipitation directly control microbial dynamics through soil wet-dry cycles, which in turn control the export of materials and nutrients into streams and groundwater. Recent research suggests that living microbial biomass can increase during the driest, hottest part of the year. We measured dissolved organic carbon and nitrogen (DOC, DON), microbial biomass carbon and nitrogen, inorganic nitrogen (NH4+, NO3-), and nitrification potential from July of 2007 to the present in California semi-arid grasslands. We also monitored inorganic nitrogen concentrations in soil pore water, shallow ground water, and stream water over the same period. Seasonal trends in DOC and DON show that they accumulate over the dry summer, and then decrease with the onset of the winter rains. Microbial biomass carbon showed a similar pattern, being higher in the summer and declining during winter (188.9413.34 and 139.218.45 ?g C g-1 dry soil respectively. However, biomass nitrogen remained unchanged over the same period (11.210.84 and 10.860.74 ?g N g-1 dry soil respectively). Nitrification potentials were lowest during the winter wet season (5.260.40 ?g N d-1 g-1 dry soil) and highest during the dry summer season (8.910.60 ?g N d-1 g-1 dry soil). However, the seasonal patterns in NH4+ and NO3- availability suggest that net nitrification was not substantial until after the winter rains began. It is not currently known whether this increase in biomass represents actual growth of new organisms, or is a result of microbes accumulating internal solutes to avoid drying out. At the landscape-scale, these microbial dynamics control the amount and composition of nutrient export from these ecosystems into groundwater and streams. Long, dry summers allow nutrients to accumulate, and then a single large precipitation event can lead to a large pulse being released. Microbial dynamics in natural ecosystems, such as NO3- production via nitrification, can have important implications for water quality (in the case of NO3-) in urban areas located downstream.

Schaeffer, S. M.; Boot, C. M.; Doyle, A.; Clark, J.; Schimel, J. P.

2008-12-01

38

Fisher Research and the Kings River Sustainable Forest Ecosystems Project: Current Results and Future Efforts 1  

Microsoft Academic Search

The Kings River Sustainable Forest Ecosystems Project was initiated on the Kings River Ranger District of the Sierra National Forest, California, in 1993, with fieldwork beginning in 1994. Knowledge of the ecology of the fisher (Martes pennanti) in the Project area, and in the Sierra Nevada of California in general, is insufficient to develop empirically based management strategies or to

Brian B. Boroski; Richard T. Golightly

2002-01-01

39

PERSISTENCE OF CHLORINATED HYDROCARBON CONTAMINATION IN A CALIFORNIA MARINE ECOSYSTEM  

EPA Science Inventory

Despite major reductions in the dominant DDT and polychlorinated biphenyls (PCB) input off Los Angeles (California, USA) in the early 1970s, the levels of these pollutants decreased only slightly from 1972 to 1975 both in surficial bottom sediments and in a flatfish bioindicator ...

40

California Coastal Upwelling Onset Variability: Cross-Shore and Bottom-Up Propagation in the Planktonic Ecosystem  

PubMed Central

The variability of the California Current System (CCS) is primarily driven by variability in regional wind forcing. In particular, the timing of the spring transition, i.e., the onset of upwelling-favorable winds, varies considerably in the CCS with changes in the North Pacific Gyre Oscillation. Using a coupled physical-biogeochemical model, this study examines the sensitivity of the ecosystem functioning in the CCS to a lead or lag in the spring transition. An early spring transition results in an increased vertical nutrient flux at the coast, with the largest ecosystem consequences, both in relative amplitude and persistence, hundreds of kilometers offshore and at the highest trophic level of the modeled food web. A budget analysis reveals that the propagation of the perturbation offshore and up the food web is driven by remineralization and grazing/predation involving both large and small plankton species. PMID:23690935

Chenillat, Fanny; Riviere, Pascal; Capet, Xavier; Franks, Peter J. S.; Blanke, Bruno

2013-01-01

41

Appreciation, Use, and Management of Biodiversity and Ecosystem Services in California's Working Landscapes  

NASA Astrophysics Data System (ADS)

"Working landscapes" is the concept of fostering effective ecosystem stewardship and conservation through active human presence and management and integrating livestock, crop, and timber production with the provision of a broad range of ecosystem services at the landscape scale. Based on a statewide survey of private landowners of "working" forests and rangelands in California, we investigated whether owners who are engaged in commercial livestock or timber production appreciate and manage biodiversity and ecosystem services on their land in different ways than purely residential owners. Both specific uses and management practices, as well as underlying attitudes and motivations toward biodiversity and ecosystem services, were assessed. Correlation analysis showed one bundle of ecosystem goods and services (e.g., livestock, timber, crops, and housing) that is supported by some landowners at the community level. Another closely correlated bundle of biodiversity and ecosystem services includes recreation, hunting/fishing, wildlife habitat, and fire prevention. Producers were more likely to ally with the first bundle and residential owners with the second. The survey further confirmed that cultural ecosystem services and quality-of-life aspects are among the primary amenities that motivate forest and rangeland ownership regardless of ownership type. To live near natural beauty was the most important motive for both landowner groups. Producers were much more active in management for habitat improvement and other environmental goals than residential owners. As the number of production-oriented owners decreases, developing strategies for encouraging environment-positive management by all types of landowners is crucial.

Plieninger, Tobias; Ferranto, Shasta; Huntsinger, Lynn; Kelly, Maggi; Getz, Christy

2012-09-01

42

Cumulative Human Impacts on Mediterranean and Black Sea Marine Ecosystems: Assessing Current Pressures and  

E-print Network

Cumulative Human Impacts on Mediterranean and Black Sea Marine Ecosystems: Assessing Current regions, including the Mediterranean and Black Sea, legal mandates and agreements to implement ecosystem on Mediterranean and Black Sea Marine Ecosystems: Assessing Current Pressures and Opportunities. PLoS ONE 8(12): e

Lewison, Rebecca

43

Turbulence Mixing and Transport Mechanisms in a Coastal Ecosystem: Bay of La Paz, Baja California Sur, Mexico  

E-print Network

ABSTRACT Turbulence Mixing and Transport Mechanisms in a Coastal Ecosystem: Bay of La Paz, Baja California Sur, Mexico. (May 2014) Burkely Ashton Pettijohn Department of Marine Sciences Texas A&M University Research Advisor: Dr. Ayal Anis...

Pettijohn, Burkely Ashton

2014-02-10

44

Global Circulation and the California Current  

NSDL National Science Digital Library

This on-line expedition focuses on the flow of ocean water along with its climatic impact and environmental consequences. Learning objectives include an awareness that ocean waters are constantly on the move, that ocean currents influence climate and living conditions for plants and animals, even on land, and that currents flow in complex patterns affected by wind, the water's salinity and heat content, bottom topography, and the earth's rotation. This expedition is one of nine expeditions and two field studies which are part of a course entitled Geology 105 - Mysteries of the Deep.

1999-03-21

45

California DOT 1. Briefly summarize your current pavement smoothness requirements.  

E-print Network

California DOT 1. Briefly summarize your current pavement smoothness requirements. For HMA pavement to OGFC placed on existing pavement not constructed under the same project. If concrete pavement is placed ordered. 39-1.12B Straightedge The top layer of HMA pavement must not vary from the lower edge of a12-foot

46

Issues of ecosystem-based management of forage fisheries in open non-stationary ecosystems: the example of the sardine fishery in the Gulf of California  

Microsoft Academic Search

The Gulf of California system presents major challenges to the still developing frameworks for ecosystem-based management\\u000a (EBM). It is very much an open system and is intermittently subject to important influxes of migratory visitors, including large pelagic predatory fishes and small\\u000a pelagic forage fishes. These migrants include the more tropical species from the coastal ecosystems to the south and perhaps

Andrew Bakun; Elizabeth A. Babcock; Salvador E. Lluch-Cota; Christine Santora; Christian J. Salvadeo

2010-01-01

47

Material properties of zooplankton and nekton from the California current  

NASA Astrophysics Data System (ADS)

This study measured the material properties of zooplankton, Pacific hake (Merluccius productus), Humboldt squid (Dosidicus gigas), and two species of myctophids (Symbolophorus californiensis and Diaphus theta) collected from the California Current ecosystem. The density contrast (g) was measured for euphausiids, decapods (Sergestes similis), amphipods (Primno macropa, Phronima sp., and Hyperiid spp.), siphonophore bracts, chaetognaths, larval fish, crab megalopae, larval squid, and medusae. Morphometric data (length, width, and height) were collected for these taxa. Density contrasts varied within and between zooplankton taxa. The mean and standard deviation for euphausiid density contrast were 1.059 +/- 0.009. Relationships between zooplankton density contrast and morphometric measurements, geographic location, and environmental conditions were investigated. Site had a significant effect on euphausiid density contrast. Density contrasts of euphausiids collected in the same geographic area approximately 4-10 days apart were significantly higher (p < 0.001). Sound speed contrast (h) was measured for euphausiids and pelagic decapods (S. similis) and it varied between taxa. The mean and standard deviation for euphausiid sound speed were 1.019 +/- 0.009. Euphausiid mass was calculated from density measurements and volume, and a relationship between euphausiid mass and length was produced. We determined that euphausiid from volumes could be accurately estimated two dimensional measurements of animal body shape, and that biomass (or biovolume) could be accurately calculated from digital photographs of animals. Density contrast (g) was measured for zooplankton, pieces of hake flesh, myctophid flesh, and of the following Humboldt squid body parts: mantle, arms, tentacle, braincase, eyes, pen, and beak. The density contrasts varied within and between fish taxa, as well as among squid body parts. Effects of animal length and environmental conditions on nekton density contrast were investigated. The sound speed contrast (h) was measured for Pacific hake flesh, myctophid flesh, Humboldt squid mantle, and Humboldt squid braincase. Sound speed varied within and between nekton taxa. The material properties reported in this study can be used to improve target strength estimates from acoustic scattering models which would increase the accuracy of biomass estimates from acoustic surveys for these zooplankton and nekton.

Becker, Kaylyn

48

Climate, fishing, and fluctuations of sardine and anchovy in the California Current.  

PubMed

Since the days of Elton, population cycles have challenged ecologists and resource managers. Although the underlying mechanisms remain debated, theory holds that both density-dependent and density-independent processes shape the dynamics. One striking example is the large-scale fluctuations of sardine and anchovy observed across the major upwelling areas of the world. Despite a long history of research, the causes of these fluctuations remain unresolved and heavily debated, with significant implications for fisheries management. We here model the underlying causes of these fluctuations, using the California Current Ecosystem as a case study, and show that the dynamics, accurately reproduced since A.D. 1661 onward, are explained by interacting density-dependent processes (i.e., through species-specific life-history traits) and climate forcing. Furthermore, we demonstrate how fishing modifies the dynamics and show that the sardine collapse of the 1950s was largely unavoidable given poor recruitment conditions. Our approach provides unique insight into the origin of sardine-anchovy fluctuations and a knowledge base for sustainable fisheries management in the California Current Ecosystem and beyond. PMID:23836661

Lindegren, Martin; Checkley, David M; Rouyer, Tristan; MacCall, Alec D; Stenseth, Nils Chr

2013-08-13

49

Climate, fishing, and fluctuations of sardine and anchovy in the California Current  

PubMed Central

Since the days of Elton, population cycles have challenged ecologists and resource managers. Although the underlying mechanisms remain debated, theory holds that both density-dependent and density-independent processes shape the dynamics. One striking example is the large-scale fluctuations of sardine and anchovy observed across the major upwelling areas of the world. Despite a long history of research, the causes of these fluctuations remain unresolved and heavily debated, with significant implications for fisheries management. We here model the underlying causes of these fluctuations, using the California Current Ecosystem as a case study, and show that the dynamics, accurately reproduced since A.D. 1661 onward, are explained by interacting density-dependent processes (i.e., through species-specific life-history traits) and climate forcing. Furthermore, we demonstrate how fishing modifies the dynamics and show that the sardine collapse of the 1950s was largely unavoidable given poor recruitment conditions. Our approach provides unique insight into the origin of sardineanchovy fluctuations and a knowledge base for sustainable fisheries management in the California Current Ecosystem and beyond. PMID:23836661

Lindegren, Martin; Checkley, David M.; Rouyer, Tristan; MacCall, Alec D.; Stenseth, Nils Chr.

2013-01-01

50

Zooplankton distribution and cross-shelf transfer of carbon in an area of complex mesoscale circulation in the northern California Current  

Microsoft Academic Search

We conducted a research cruise in late summer (JulyAugust) 2000 to study the effect of mesoscale circulation features on zooplankton distributions in the coastal upwelling ecosystem of the northern California Current. Our study area was in a region of complex coastline and bottom topography between Newport, Oregon (44.7N), and Crescent City, California (41.9N). Winds were generally strong and equatorward for

J. E. Keister; W. T. Peterson; S. D. Pierce

2009-01-01

51

Effects of selenium supplementation in cattle on aquatic ecosystems in northern California  

SciTech Connect

The potential impact on aquatic ecosystems of supplementing the diets of beef cattle with selenium (Se) was studied on 4 northern California ranches. All study sites included an area of concentrated use by cattle that had diets supplemented with Se. In each case, a stream flowed through the site and provided a control sampling area upstream and a treated sampling area downstream. Specimens of water, sediment, algae, aquatic plants, aquatic invertebrates, and fish were analyzed fluorometrically for total Se content. Significant differences in Se concentration were not found between specimens from upstream control areas and those from downstream areas subjected to use by Se-treated cattle. Evidence was not found that Se supplementation in cattle at maximal permitted concentrations caused Se accumulation in associated aquatic ecosystems.

Norman, B.; Nader, G.; Oliver, M.; Delmas, R.; Drake, D.; George, H. (School of Veterinary Medicine, University of California, Davis (United States))

1992-09-15

52

SAFRR Tsunami Scenario. Preparedness and Resilience for California's ecosystems, natural resources, and the communities that depend on them  

NASA Astrophysics Data System (ADS)

The SAFRR Tsunami Scenario models a plausible 9.1MP earthquake occuring off the Alaskan coast, that generates a tsunami forecast to strike California between 4-6 hour after the event. California's diverse ecosystems, natural resources, and sensitive species will be significantly affected. Although often overlooked in disaster risk reduction, damage to ecosystems and natural resources during hazards including tsunamis, has often resulted in serious impacts to natural systems and on humans who depend on them. SAFRR tsunami scenario forecasts of wave amplitude, water velocity and inundation and overlain on GIS maps were analyzed to identify plausible impacts on California's ecosystems including beaches, marshes, nearshore subtidal habitats, as well as parks and reserves. The effect on natural resources including fisheries was evaluated. Recovery times and consequences were analyzed. The results illustrate the value and vulnerability of these resources and guidelines for preparation and mitigation are discussed.

Brosnan, D. M.

2013-12-01

53

Accumulation of current-use and organochlorine pesticides in crab embryos from Northern California, USA  

USGS Publications Warehouse

Invertebrates have long been used as resident sentinels for assessing ecosystem health and productivity. The shore crabs, Hemigrapsus oregonensis and Pachygrapsus crassipes, are abundant in estuaries and beaches throughout northern California, USA and have been used as indicators of habitat conditions in several salt marshes. The overall objectives of the present study were to conduct a lab-based study to test the accumulation of current-use pesticides, validate the analytical method and to analyze field-collected crabs for a suite of 74 current-use and legacy pesticides. A simple laboratory uptake study was designed to determine if embryos could bioconcentrate the herbicide molinate over a 7-d period. At the end of the experiment, embryos were removed from the crabs and analyzed by gas chromatography/mass spectrometry. Although relatively hydrophilic (log KOW of 2.9), molinate did accumulate with an estimated bioconcentration factor (log BCF) of approximately 2.5. Following method validation, embryos were collected from two different Northern California salt marshes and analyzed. In field-collected embryos 18 current-use and eight organochlorine pesticides were detected including synthetic pyrethroids and organophosphate insecticides, as well as DDT and its degradates. Lipid-normalized concentrations of the pesticides detected in the field-collected crab embryos ranged from 0.1 to 4 ppm. Pesticide concentrations and profiles in crab embryos were site specific and could be correlated to differences in land-use practices. These preliminary results indicate that embryos are an effective sink for organic contaminants in the environment and have the potential to be good indicators of ecosystem health, especially when contaminant body burden analyses are paired with reproductive impairment assays.

Smalling, Kelly L.; Morgan, Steven; Kuivila, Kathryn K.

2010-01-01

54

Accumulation of current-use and organochlorine pesticides in crab embryos from northern California, USA.  

PubMed

Invertebrates have long been used as resident sentinels for assessing ecosystem health and productivity. The shore crabs, Hemigrapsus oregonensis and Pachygrapsus crassipes, are abundant in estuaries and beaches throughout northern California, USA and have been used as indicators of habitat conditions in several salt marshes. The overall objectives of the present study were to conduct a lab-based study to test the accumulation of current-use pesticides, validate the analytical method and to analyze field-collected crabs for a suite of 74 current-use and legacy pesticides. A simple laboratory uptake study was designed to determine if embryos could bioconcentrate the herbicide molinate over a 7-d period. At the end of the experiment, embryos were removed from the crabs and analyzed by gas chromatography/mass spectrometry. Although relatively hydrophilic (log K(OW) of 2.9), molinate did accumulate with an estimated bioconcentration factor (log BCF) of approximately 2.5. Following method validation, embryos were collected from two different Northern California salt marshes and analyzed. In field-collected embryos 18 current-use and eight organochlorine pesticides were detected including synthetic pyrethroids and organophosphate insecticides, as well as DDT and its degradates. Lipid-normalized concentrations of the pesticides detected in the field-collected crab embryos ranged from 0.1 to 4 ppm. Pesticide concentrations and profiles in crab embryos were site specific and could be correlated to differences in land-use practices. These preliminary results indicate that embryos are an effective sink for organic contaminants in the environment and have the potential to be good indicators of ecosystem health, especially when contaminant body burden analyses are paired with reproductive impairment assays. PMID:20853457

Smalling, Kelly L; Morgan, Steven; Kuivila, Kathryn K

2010-11-01

55

DDT RESIDUES IN SEAWATER AND PARTICULATE MATTER IN THE CALIFORNIA CURRENT SYSTEM  

E-print Network

DDT RESIDUES IN SEAWATER AND PARTICULATE MATTER IN THE CALIFORNIA CURRENT SYSTEM JAMES L. COX in the California current system were analyzed for DDT residues. DDT residue concentrations in whole seawater and Washington, to 5.6 X 10- 12 glml off southern California. Geographical patterns in these concentration values

56

Importance of jumbo squid Dosidicus gigas (Orbigny, 1835) in the pelagic ecosystem of the central Gulf of California  

Microsoft Academic Search

The Humboldt squid is an important predator in the pelagic ecosystem of the central Gulf of California and the commercial catch of this species has increased over the past decade, probable due to a decrease of several top predators (sharks, large pelagic fish and the marine mammals) and the optimal feeding conditions in this area. Its high abundance and important

R. Rosas-Luis; C. A. Salinas-Zavala; V. Koch; P. Del Monte Luna; M. V. Morales-Zrate

2008-01-01

57

Depth-integrated estimates of ecosystem metabolism in a high-elevation lake (Emerald Lake, Sierra Nevada, California)  

E-print Network

methods of estimating whole-lake metabolism. During periods of stratification, flux across the thermoclineDepth-integrated estimates of ecosystem metabolism in a high-elevation lake (Emerald Lake, Sierra in an oligotrophic high-elevation lake (Emerald Lake, California) were used to investigate volumetric and areal rates

California at Santa Barbara, University of

58

Bering Climate: A Current View of the Bering Sea Ecosystem and Climate  

NSDL National Science Digital Library

This portal provides a current review of the ecosystem and climate of the Bering Sea. One link provides access to an article featuring an overview of the current state of the sea in terms of ecosystem and climate change. The "Quick View" segment provides graphic representations of how four indicators (physical data, biology and fisheries, climate indices, and composites) have changed over time. Other links provide access to datasets, science reports and essays, and to additional information such as maps and photographs.

59

Spatial ecology of krill, micronekton and top predators in the central California Current: Implications for defining ecologically important areas  

NASA Astrophysics Data System (ADS)

Marine spatial planning and ecosystem models that aim to predict and protect fisheries and wildlife benefit greatly from syntheses of empirical information on physical and biological partitioning of marine ecosystems. Here, we develop spatially-explicit oceanographic and ecological descriptions of the central California Current region. To partition this region, we integrate data from 20 years of shipboard surveys with satellite remote-sensing to characterize local seascapes of ecological significance, focusing on krill, other micronekton taxa, and top predators (seabirds and marine mammals). Specifically, we investigate if micronekton and predator assemblages co-vary spatially with mesoscale oceanographic conditions. The first principal component of environmental and micronekton seascapes indicates significant coupling between physics, primary productivity, and secondary and tertiary marine consumers. Subsequent principal components indicate latitudinal variability in niche-community space due to varying habitat characteristics between Monterey Bay (deep submarine canyon system) and the Gulf of the Farallones (extensive continental shelf), even though both of these sub-regions are located downstream from upwelling centers. Overall, we identified five ecologically important areas based on spatial integration of environmental and biotic features. These areas, characterized by proximity to upwelling centers, shallow pycnoclines, and high chlorophyll-a and krill concentrations, are potential areas of elevated trophic focusing for specific epipelagic and mesopelagic communities. This synthesis will benefit ecosystem-based management approaches for the central California Current, a region long-impacted by anthropogenic factors.

Santora, Jarrod A.; Field, John C.; Schroeder, Isaac D.; Sakuma, Keith M.; Wells, Brian K.; Sydeman, William J.

2012-11-01

60

Anthropogenic degradation of the southern California desert ecosystem and prospects for natural recovery and restoration  

USGS Publications Warehouse

Large areas of the southern California desert ecosystem have been negatively affected by off-highway vehicle use, overgrazing by domestic livestock, agriculture, urbanization, construction of roads and utility corridors, air pollution, military training exercises, and other activities. Secondary contributions to degradation include the proliferation of exotic plant species and a higher frequency of an- thropogenic fire. Effects of these impacts include alteration or destruction of macro- and micro- vegetation elements, establishment of annual plant communities dominated by exotic species, destruction of soil stabilizers, soil compaction, and increased erosion. Published estimates of recovery time are based on return to predisturbance levels of biomass, cover, density, community structure, or soil characteristics. Natural recovery rates depend on the nature and severity of the impact but are generally very slow. Recovery to predisturbance plant cover and biomass may take 50-300 years, while complete ecosystem recovery may require over 3000 years. Restorative intervention can be used to enhance the success and rate of recovery, but the costs are high and the probability for long-term success is low to moderate. Given the sensitivity of desert habitats to disturbance and the slow rate of natural recovery, the best management option is to limit the extent and intensity of impacts as much as possible.

Lovich, J.E.; Bainbridge, D.

1999-01-01

61

Nine endangered taxa, one recovering ecosystem: Identifying common ground for recovery on Santa Cruz Island, California  

USGS Publications Warehouse

It is not uncommon to have several rare and listed taxa occupying habitats in one landscape or management area where conservation amounts to defense against the possibility of further loss. It is uncommon and extremely exciting, however, to have several listed taxa occupying one island that is managed cooperatively for conservation and recovery. On Santa Cruz Island, the largest of the northern California island group in the Santa Barbara Channel, we have a golden opportunity to marry ecological knowledge and institutional "good will" in a field test of holistic rare plant conservation. Here, the last feral livestock have been removed, active weed control is underway, and management is focused on understanding and demonstrating system response to conservation management. Yet funding limitations still exist and we need to plan the most fiscally conservative and marketable approach to rare plant restoration. We still experience the tension between desirable quick results and the ecological pace of system recovery. Therefore, our research has focused on identifying fundamental constraints on species recovery at individual, demographic, habitat, and ecosystem levels, and then developing suites of actions that might be taken across taxa and landscapes. At the same time, we seek a performance middle ground that balances an institutional need for quick demonstration of hands-on positive results with a contrasting approach that allows ecosystem recovery to facilitate species recovery in the long term. We find that constraints vary across breeding systems, life-histories, and island locations. We take a hybrid approach in which we identify several actions that we can take now to enhance population size or habitat occupancy for some taxa by active restoration, while allowing others to recover at the pace of ecosystem change. We make our recommendations on the basis of data we have collected over the last decade, so that management is firmly grounded in ecological observation.

McEachern, A. Kathryn; Wilken, Dieter H.

2011-01-01

62

Differential Distributions of Synechococcus Subgroups Across the California Current System  

PubMed Central

Synechococcus is an abundant marine cyanobacterial genus composed of different populations that vary physiologically. Synechococcus narB gene sequences (encoding for nitrate reductase in cyanobacteria) obtained previously from isolates and the environment (e.g., North Pacific Gyre Station ALOHA, Hawaii or Monterey Bay, CA, USA) were used to develop quantitative PCR (qPCR) assays. These qPCR assays were used to quantify populations from specific narB phylogenetic clades across the California Current System (CCS), a region composed of dynamic zones between a coastal-upwelling zone and the oligotrophic Pacific Ocean. Targeted populations (narB subgroups) had different biogeographic patterns across the CCS, which appear to be driven by environmental conditions. Subgroups C_C1, D_C1, and D_C2 were abundant in coastal-upwelling to coastal-transition zone waters with relatively high to intermediate ammonium, nitrate, and chl. a concentrations. Subgroups A_C1 and F_C1 were most abundant in coastal-transition zone waters with intermediate nutrient concentrations. E_O1 and G_O1 were most abundant at different depths of oligotrophic open-ocean waters (either in the upper mixed layer or just below). E_O1, A_C1, and F_C1 distributions differed from other narB subgroups and likely possess unique ecologies enabling them to be most abundant in waters between coastal and open-ocean waters. Different CCS zones possessed distinct Synechococcus communities. Core California current water possessed low numbers of narB subgroups relative to counted Synechococcus cells, and coastal-transition waters contained high abundances of Synechococcus cells and total number of narB subgroups. The presented biogeographic data provides insight on the distributions and ecologies of Synechococcus present in an eastern boundary current system. PMID:21833315

Paerl, Ryan W.; Johnson, Kenneth S.; Welsh, Rory M.; Worden, Alexandra Z.; Chavez, Francisco P.; Zehr, Jonathan P.

2011-01-01

63

Measurement of Ecosystem Metabolism across Climatic and Vegetation Gradients in California  

NASA Astrophysics Data System (ADS)

Terrestrial ecosystem models require information on vegetation structure, phenology, demographics, biochemistry, radiation properties, and physiology in order to accurately simulate the responses of ecosystem functioning to global change and disturbances. These models generally depend on a small number of intensive, fine-scaled point-based measurements from eddy covariance towers, detailed vegetation surveys, literature values, and site-scale data assimilation techniques to improve model calibration. However, the limited geographic and/or temporal scope of measurements can lead to inadequate model generalizations of modeled carbon (C), water, and energy fluxes across broad regions and relevant time periods. Remote sensing approaches, particularly imaging spectroscopy (IS) and thermal infrared (TIR) data, have the potential to provide the broad-scale spatial and temporal dynamics in many important vegetation properties related to ecosystem functioning. As part of the ongoing NASA HyspIRI Airborne Campaign (http://hyspiri.jpl.nasa.gov/airborne) we are assessing the potential of IS+TIR to generate spatially explicit estimates of two important parameters characterizing plant photosynthetic capacity: the maximum rate of CO2 carboxylation by RuBisCo (Vcmax), and the maximum rate of electron transport required for the regeneration of RuBP needed in Calvin Cycle processes (Jmax). These estimates are based on recent evidence that both properties can be predicted at the leaf level using spectroscopy techniques (Ainsworth et al. 2013 [http://tinyurl.com/n5xnzjg]; Serbin et al. 2012 [http://tinyurl.com/mhocmlz]). It follows that estimation of these variables from remotely sensed IS+TIR (i.e. AVIRIS & MASTER) could facilitate the prediction of seasonal C assimilation across large areas using data from the anticipated HyspIRI satellite mission. Our research focuses on two climate-elevation transects in California, which span a vegetation gradient from coastal sage and chaparral to oak woodlands and closed-canopy coniferous forests, as well as agro-ecosystems located throughout the Central and Imperial Valleys. We are also comparing remotely sensed estimates of ecosystem photosynthetic capacity with C flux data from a series of 10 eddy covariance towers. Results from the 2013 field season highlight the large range in sampled vegetation structure, optical properties (i.e. reflectance and transmittance) and physiology (i.e. Vcmax, Jmax, and cholorphyll fluorescence). Using approaches similar to Serbin et al. (2012) we have confirmed the ability of spectroscopy to estimate Vcmax and Jmax across these diverse and structurally complex vegetation types. Ecosystem products, such as gross primary productivity, estimated from flux towers highlight the relationship between climatic parameters and vegetation productivity. Multiple data-years allow this relationship to be examined under various climatic forcings including drought and heat stress. Based on these preliminary results, our next step is to scale leaf-level information to AVIRIS footprints using radiative transfer and statistical modeling approaches with ecosystem modeling in order to assess the IS data products against flux tower observations.

DuBois, S.; Serbin, S.; Desai, A. R.; Kruger, E.; Kingdon, C.; Goulden, M.; Townsend, P. A.

2013-12-01

64

Modeling Hawaiian ecosystem degradation due to invasive plants under current and future climates  

USGS Publications Warehouse

Occupation of native ecosystems by invasive plant species alters their structure and/or function. In Hawaii, a subset of introduced plants is regarded as extremely harmful due to competitive ability, ecosystem modification, and biogeochemical habitat degradation. By controlling this subset of highly invasive ecosystem modifiers, conservation managers could significantly reduce native ecosystem degradation. To assess the invasibility of vulnerable native ecosystems, we selected a proxy subset of these invasive plants and developed robust ensemble species distribution models to define their respective potential distributions. The combinations of all species models using both binary and continuous habitat suitability projections resulted in estimates of species richness and diversity that were subsequently used to define an invasibility metric. The invasibility metric was defined from species distribution models with 0.8; True Skill Statistic >0.75) as evaluated per species. Invasibility was further projected onto a 2100 Hawaii regional climate change scenario to assess the change in potential habitat degradation. The distribution defined by the invasibility metric delineates areas of known and potential invasibility under current climate conditions and, when projected into the future, estimates potential reductions in native ecosystem extent due to climate-driven invasive incursion. We have provided the code used to develop these metrics to facilitate their wider use (Code S1). This work will help determine the vulnerability of native-dominated ecosystems to the combined threats of climate change and invasive species, and thus help prioritize ecosystem and species management actions.

Vorsino, Adam E.; Fortini, Lucas B.; Amidon, Fred A.; Miller, Stephen E.; Jacobi, James D.; Price, Jonathan P.; Gon, Sam 'Ohukani'ohi'a, III; Koob, Gregory A.

2014-01-01

65

Ecosystems  

NSDL National Science Digital Library

This self-contained module on ecosystems includes a range of fun activities that students can perform in the classroom and at home with family members. They impart important concepts such as observation, identification, measurement, and differentiation.

Science, Houghton M.

66

Identifying Key Vulnerabilities in Current Management of California Central Valley for the California Water Plan  

NASA Astrophysics Data System (ADS)

The California Department of Water Resources (DWR), for its 2013 Update of the California Water Plan (CWP), is building new analytic capabilities for developing and evaluating regional and state-wide water management strategies. These strategies are intended to address growing and diverse water needs coupled with uncertain future hydrologic conditions and available supplies. Recognizing the significant uncertainty about future water management conditions, DWR is utilizing new robust decision methods to identify robust and adaptive water management strategies. This talk will describe a recently completed application of Robust Decision Making (RDM) for long-term water planning as part of the 2013 CWP Update. This analysis utilizes a new hydrologic / water management model of the Sacramento River, San Joaquin River, and Tulare hydrologic regions, running the model under hundreds of potential futures. These futures consider potential variation in demographic growth, land-use patterns, drought length and timing, and other climate factors from projections generated by downscaled global circulation models. Cluster-finding "scenario discovery" algorithms, applied to the resulting database of simulation model results, identify the key characteristics of future conditions where current management fails to meet a wide range of policy objectives. These "vulnerabilities" provide the foundation for developing more robust and adaptive response packages and the considering tradeoffs between such response packages. This analysis will provide guidance for considering response packages to meet the challenges posed by future conditions in the California Central Valley and provides a widely applicable new approach for making water management plans more cognizant and responsive to a wide range of uncertainties.

Bloom, E.; Groves, D.; Joyce, B. A.; Juricich, R.

2012-12-01

67

Surface nutrient enrichment in the California Current off Southern California: description and possible causes  

NASA Astrophysics Data System (ADS)

Concentrations of inorganic plant nutrients in California Current waters are frequently greater near the surface than deeper in the euphotic zone. This surface nutrient enrichment (conversely, shallow subsurface nutrient minima) is poorly described. We used data from the 1983-1995 quarterly California Cooperative Oceanic Fisheries Investigations surveys to characterize surface nutrient enrichment better and to examine causal hypotheses. Averaged over the survey area, frequency of occurrence (% of stations) of enrichment was: phosphate 28%; silicate 51%; nitrate 8%; nitrite 2%. Enrichment frequency, strength and depth, and the thickness of minima layers showed spatial (latitudinal, onshore-offshore) and temporal (seasonal and year-to-year) trends. Co-occurrence, at a given station, of enrichment in two nutrients was nearly random. Apparently, enrichment of different nutrients is driven by independent factors or may be out of phase. Wind speed, wave height, and cloud cover had little effect on enrichment strength, depth, and thickness of minima layers. Potential causes of surface nutrient enrichment include atmospheric deposition, bubble concentration, vertical and horizontal circulation, differences between rates of nutrient uptake and regeneration, photoinhibition, photochemistry, and vertical migrations. Relative importance of these possible contributors is unknown, but some appear minor based on arguments using the CalCOFI data. We believe an imbalance between nutrient consumption and regeneration by euphotic zone plankton is the most important factor in producing surface nutrient enrichment; least important are atmospheric deposition, bubbles, horizontal advection and vertical circulation.

Haury, Loren; Shulenberger, Eric

1998-08-01

68

Three Interacting Freshwater Plumes in the Northern California Current System1 , R. McCabe2  

E-print Network

Three Interacting Freshwater Plumes in the Northern California Current System1 2 3 4 B. Hickey1 , R14 The northern California Current System is impacted by two primary freshwater sources: the15 Strait canyons.36 The primary sources of freshwater in summer are the Fraser River, whose water enters the Strait

Hickey, Barbara

69

Modeling the temperature-nitrate relationship in the coastal upwelling domain of the California Current  

NASA Astrophysics Data System (ADS)

Given the importance of nitrate in sustaining high primary production and fishery yields in eastern boundary current ecosystems, it is desirable to know the amounts of this nutrient reaching the euphotic zone through the upwelling process. Because such measurements are not routinely available, we developed predictive models of water-column (0-200 m) nitrate based on temperature for a region of the California Current System (30-47N) within 50 km from the coast. Prediction was done using generalized additive models based on a compilation of 37,607 observations collected over the period 1959-2004 and validated with a separate set of 6430 observations for the period 2005-2011. A temperature-only model had relatively high explanatory power (explained deviance, D2 = 71.6%) but contained important depth, latitudinal, and seasonal biases. A model incorporating salinity in addition to temperature (D2 = 91.2%) corrected for the latitudinal and depth biases but not the seasonal bias. The best model included oxygen, temperature, and salinity (D2 = 96.6%) and adequately predicted nitrate temporal behavior at two widely separated locations (4439.1'N and 3254.6'N) with slight or no bias [root-mean-square error (RMSE) = 2.39 and 0.40 M, respectively). For situations when only temperature is available, a model including depth, month, and latitude as proxy covariates corrects some of the biases, but it had lower predictive skill (RMSE = 2.50 and 5.22 ?M, respectively). The results of this study have applications for the proxy derivation of nitrate availability for primary producers (phytoplankton, macroalgae) in upwelling regions and for biogeochemical and ecosystem modeling studies.

Palacios, Daniel M.; Hazen, Elliott L.; Schroeder, Isaac D.; Bograd, Steven J.

2013-07-01

70

Water Quality in South San Francisco Bay, California: Current Condition and Potential  

E-print Network

Water Quality in South San Francisco Bay, California: Current Condition and Potential Issues and Wetland Restoration . . . . . . . . . . . . . . . . . . . . 117 2 Current Water Quality Aspects of Water Quality . . . . . . . . . . . . . . . . . . . . . . 130 3 Potential Future Changes

71

Ecosystems  

NSDL National Science Digital Library

This "Ecosystems" module has four units of instruction. The units include: natural selection, population balance, exchange cycles, and environmental protection. Each module has a "Hazards" link that leads to a menu of study units on various environmental hazards (such as oil spills, farm runoff, insecticides, and so on).

Klemm, W. R.

2002-01-01

72

Spatialtemporal variation in soil respiration in an oakgrass savanna ecosystem in California and its partitioning into autotrophic and heterotrophic components  

Microsoft Academic Search

The spatial upscaling of soil respiration from field measurements to ecosystem levels will be biased without studying its spatial variation. We took advantage of the unique spatial gradients of an oakgrass savanna ecosystem in California, with widely spaced oak trees overlying a grass layer, to study the spatial variation in soil respiration and to use these natural gradients to partition

Jianwu Tang; Dennis D. Baldocchi

2005-01-01

73

Fire and aquatic ecosystems of the western USA: Current knowledge and key questions  

USGS Publications Warehouse

Understanding of the effects of wildland fire and fire management on aquatic and riparian ecosystems is an evolving field, with many questions still to be resolved. Limitations of current knowledge, and the certainty that fire management will continue, underscore the need to summarize available information. Integrating fire and fuels management with aquatic ecosystem conservation begins with recognizing that terrestrial and aquatic ecosystems are linked and dynamic, and that fire can play a critical role in maintaining aquatic ecological diversity. To protect aquatic ecosystems we argue that it will be important to: (1) accommodate fire-related and other ecological processes that maintain aquatic habitats and biodiversity, and not simply control fires or fuels; (2) prioritize projects according to risks and opportunities for fire control and the protection of aquatic ecosystems; and (3) develop new consistency in the management and regulatory process. Ultimately, all natural resource management is uncertain; the role of science is to apply experimental design and hypothesis testing to management applications that affect fire and aquatic ecosystems. Policy-makers and the public will benefit from an expanded appreciation of fire ecology that enables them to implement watershed management projects as experiments with hypothesized outcomes, adequate controls, and replication.

Bisson, P. A.; Rieman, B.; Luce, C.; Hessburg, P. F.; Lee, D.; Kershner, J.; Reeves, G. H.; Gresswell, Robert E.

2003-01-01

74

Decadal changes in the Canary Current Upwelling Ecosystem  

NASA Astrophysics Data System (ADS)

The Canary Current Upwelling System (CCUS) covers the latitudinal range 12-43 degrees N and has some singularities in relation to the other three major Eastern Boundary Upwelling Systems (EBUS), namely a major interruption in the continuity of the system at the Strait of Gibraltar and it is the only one with a sardine species from a different genus (Sardina vs Sardinops). Long-term trends in ocean temperature and coastal upwelling were investigated using the AVHRR Pathfinder SST (sea surface temperature) Version 5.1 dataset, in situ SST from the International Comprehensive Ocean-Atmosphere Data Set (ICOADS), and upwelling indices from the Pacific Fisheries Environmental Laboratory (PFEL). The analysis is applied to the eastern boundary of the North Atlantic, from 10 to 45 degrees N extending until 30 degrees W, focusing mainly in the CCUS because the strong dynamic link between the atmosphere and the ocean makes upwelling regions highly sensitive to global change and ideal to monitor and investigate its effects. The detail in SST variability results in a large extent from the fine analysis and the numerical processing carefully designed to avoid trend bias in the climatological studies. The obtained fields of SST trends show a generalized warming of the entire region. However, alternate patches of significantly different warming rates are observed, ranging from large scale down to mesoscale. Known coastal upwelling features are seen to warm at a lower rate than corresponding offshore waters, pointing to an intensification of the upwelling in the last decades. Wind data are used to attempt to explain the variability of some upwelling structures. Our results evidence the main role that mesoscale processes play in the modulation of the spatial and temporal variability of SST, namely at the decadal scale. This result prevents any global conclusion about the intensification of the upwelling at the scale of the entire CCUS. The bulk of the sardine population is located in the southern part of CCUS off NW Africa. Important fluctuations in landings have been observed in the last 70 years but they seem to be out of phase between the two sub-regions - the northern CCUS (Iberia) and southern CCUS (NW Africa). The explanation for these fluctuations has been related, at least partially, to environmental drivers but also to changes in exploitation. Landing time series of sardine, anchovy and sardinella were used to perform an exploratory analysis to investigate the relationships between small pelagic fish species in the CCUS and decadal changes in SST and coastal upwelling. This is a contribution to FCT (Portuguese Science and Technology Foundation) funded projects LONGUP (PTDC/AAC-CLI/105296/2008) and MODELA (PTDC/MAR/098643/2008).

Santos, A. M.; Luis, J. M.; Relvas-Almeida, P.

2013-12-01

75

Modeling Hawaiian Ecosystem Degradation due to Invasive Plants under Current and Future Climates  

PubMed Central

Occupation of native ecosystems by invasive plant species alters their structure and/or function. In Hawaii, a subset of introduced plants is regarded as extremely harmful due to competitive ability, ecosystem modification, and biogeochemical habitat degradation. By controlling this subset of highly invasive ecosystem modifiers, conservation managers could significantly reduce native ecosystem degradation. To assess the invasibility of vulnerable native ecosystems, we selected a proxy subset of these invasive plants and developed robust ensemble species distribution models to define their respective potential distributions. The combinations of all species models using both binary and continuous habitat suitability projections resulted in estimates of species richness and diversity that were subsequently used to define an invasibility metric. The invasibility metric was defined from species distribution models with <0.7 niche overlap (Warrens I) and relatively discriminative distributions (Area Under the Curve >0.8; True Skill Statistic >0.75) as evaluated per species. Invasibility was further projected onto a 2100 Hawaii regional climate change scenario to assess the change in potential habitat degradation. The distribution defined by the invasibility metric delineates areas of known and potential invasibility under current climate conditions and, when projected into the future, estimates potential reductions in native ecosystem extent due to climate-driven invasive incursion. We have provided the code used to develop these metrics to facilitate their wider use (Code S1). This work will help determine the vulnerability of native-dominated ecosystems to the combined threats of climate change and invasive species, and thus help prioritize ecosystem and species management actions. PMID:24805254

Vorsino, Adam E.; Fortini, Lucas B.; Amidon, Fred A.; Miller, Stephen E.; Jacobi, James D.; Price, Jonathan P.; Gon, Sam 'Ohukani'ohi'a; Koob, Gregory A.

2014-01-01

76

Modeling Hawaiian ecosystem degradation due to invasive plants under current and future climates.  

PubMed

Occupation of native ecosystems by invasive plant species alters their structure and/or function. In Hawaii, a subset of introduced plants is regarded as extremely harmful due to competitive ability, ecosystem modification, and biogeochemical habitat degradation. By controlling this subset of highly invasive ecosystem modifiers, conservation managers could significantly reduce native ecosystem degradation. To assess the invasibility of vulnerable native ecosystems, we selected a proxy subset of these invasive plants and developed robust ensemble species distribution models to define their respective potential distributions. The combinations of all species models using both binary and continuous habitat suitability projections resulted in estimates of species richness and diversity that were subsequently used to define an invasibility metric. The invasibility metric was defined from species distribution models with <0.7 niche overlap (Warrens I) and relatively discriminative distributions (Area Under the Curve >0.8; True Skill Statistic >0.75) as evaluated per species. Invasibility was further projected onto a 2100 Hawaii regional climate change scenario to assess the change in potential habitat degradation. The distribution defined by the invasibility metric delineates areas of known and potential invasibility under current climate conditions and, when projected into the future, estimates potential reductions in native ecosystem extent due to climate-driven invasive incursion. We have provided the code used to develop these metrics to facilitate their wider use (Code S1). This work will help determine the vulnerability of native-dominated ecosystems to the combined threats of climate change and invasive species, and thus help prioritize ecosystem and species management actions. PMID:24805254

Vorsino, Adam E; Fortini, Lucas B; Amidon, Fred A; Miller, Stephen E; Jacobi, James D; Price, Jonathan P; Gon, Sam 'ohukani'ohi'a; Koob, Gregory A

2014-01-01

77

ALONGSHORE VARIABILITY OF THE CALIFORNIA CURRENT SYSTEM FROM CENTRAL TO BAJA CALIFORNIA IN WINTER AND SPRING 2003: PHYSICAL, CHEMICAL AND BIOLOGICAL PROPERTIES  

E-print Network

AND SPRING 2003: PHYSICAL, CHEMICAL AND BIOLOGICAL PROPERTIES ALONGSHORE VARIABILITY OF THE CALIFORNIA IN WINTER AND SPRING 2003: PHYSICAL, CHEMICAL AND BIOLOGICAL PROPERTIES ALONGSHORE VARIABILITY CURRENT SYSTEM FROM CENTRAL TO BAJA CALIFORNIA IN WINTER AND SPRING 2003: PHYSICAL, CHEMICAL

Pennington, J. Timothy

78

Parallel adjustments in vegetation greenness and ecosystem CO 2 exchange in response to drought in a Southern California chaparral ecosystem  

Microsoft Academic Search

Some form of the light use efficiency (LUE) model is used in most models of ecosystem carbon exchange based on remote sensing. The strong relationship between the normalized difference vegetation index (NDVI) and light absorbed by green vegetation make models based on LUE attractive in the remote sensing context. However, estimation of LUE has proven problematic since it varies with

Daniel A. Sims; Hongyan Luo; Steven Hastings; Walter C. Oechel; Abdullah F. Rahman; John A. Gamon

2006-01-01

79

Use and Management of Mediterranean Ecosystems in South Africa--Current  

E-print Network

problems in Mountain Fynbos. PATTERNS AND TRENDS IN LAND-USE AND MANAGEMENT History Changes by man to Cape of South Africa and, in greater detail, aspects of current management of fynbos mountain catchments management. Ecosystems of the mediterranean type in South Africa include Mountain Fynbos, Coastal Fynbos

Standiford, Richard B.

80

CURRENT BREEDING STATUS OF THE YELLOW HEADED BLACKBIRD IN CALIFORNIA  

Microsoft Academic Search

of 1971,we also recorded observations on Yellow-headed Blackbirds (Xanthocephalus xanthocephalus). These observations are reported here and compared with published information on the historical breeding status of Yellow-headed Blackbirds in California. Regions containing potential breeding habitat for blackbirds were identified from topographic maps and systematically searched during the breeding season. Over 8,000 miles were driven within California between 23 April and

Frederick T. Crase; Richard W. DeHaven

1972-01-01

81

Foraging ecology and movement patterns of jumbo squid (Dosidicus gigas) in the California Current System  

NASA Astrophysics Data System (ADS)

From 2002 to 2010, the jumbo squid (Dosidicus gigas) has been regularly encountered in large numbers throughout the California Current System (CCS). This species, usually found in subtropical waters, could affect coastal pelagic ecosystems and fisheries as both predator and prey. Neither the abundance of jumbo squid nor the optimal ocean conditions in which they flourish are well known. To understand better the potential impacts of this species on both commercial fisheries and on food-web structure we collected nearly 900 specimens from waters of the CCS, covering over 20 of latitude, over a range of depths and seasons. We used demographic information (size, sex, and maturity state) and analyzed stomach contents using morphological and molecular methods to best understand the foraging ecology of this species in different habitats of the CCS. Squid were found to consume a broad array of prey. Prey in offshore waters generally reflected the forage base reported in previous studies (mainly mesopelagic fishes and squids), whereas in more coastal waters (shelf, shelf break and slope habitats) squid foraged on a much broader mix that included substantial numbers of coastal pelagic fishes (Pacific herring and northern anchovy, as well as osmerids and salmonids in northern waters) and groundfish (Pacific hake, several species of rockfish and flatfish). We propose a seasonal movement pattern, based on size and maturity distributions along with qualitative patterns of presence or absence, and discuss the relevance of both the movement and distribution of jumbo squid over space and time. We find that jumbo squid are a generalist predator, which feeds primarily on small, pelagic or mesopelagic micronekton but also on larger fishes when they are available. We also conclude that interactions with and potential impacts on ecosystems likely vary over space and time, in response to both seasonal movement patterns and highly variable year-to-year abundance of the squid themselves.

Field, John C.; Elliger, Carl; Baltz, Ken; Gillespie, Graham E.; Gilly, William F.; Ruiz-Cooley, R. I.; Pearse, Devon; Stewart, Julia S.; Matsubu, William; Walker, William A.

2013-10-01

82

Processes influencing seasonal hypoxia in the northern California Current System  

PubMed Central

This paper delineates the role of physical and biological processes contributing to hypoxia, dissolved oxygen (DO) < 1.4 mL/L, over the continental shelf of Washington State in the northern portion of the California Current System (CCS). In the historical record (19501986) during the summer upwelling season, hypoxia is more prevalent and severe off Washington than further south off northern Oregon. Recent data (20032005) show that hypoxia over the Washington shelf occurred at levels previously observed in the historical data. 2006 was an exception, with hypoxia covering ~5000 km2 of the Washington continental shelf and DO concentrations below 0.5 mL/L at the inner shelf, lower than any known previous observations at that location. In the four years studied, upwelling of low DO water and changes in source water contribute to interannual variability, but cannot account for seasonal decreases below hypoxic concentrations. Deficits of DO along salinity surfaces, indicating biochemical consumption of DO, vary significantly between surveys, accounting for additional decreases of 0.52.5 mL/L by late summer. DO consumption is associated with denitrification, an indicator of biochemical sediment processes. Mass balances of DO and nitrate show that biochemical processes in the water column and sediments each contribute ~50% to the total consumption of DO in near-bottom water. At shorter than seasonal time scales on the inner shelf, along-shelf advection of hypoxic patches and cross-shelf advection of seasonal gradients are both shown to be important, changing DO concentrations by 1.5 mL/L or more over five days. PMID:20463844

Connolly, T. P.; Hickey, B. M.; Geier, S. L.; Cochlan, W. P.

2010-01-01

83

Predictive Relationships for pH and Carbonate Saturation in the Southern California Current System Using Oxygen and Temperature Data  

NASA Astrophysics Data System (ADS)

The California Current System is expected to experience the ecological impacts of ocean acidification earlier than most other ocean regions because marine waters in the North Pacific are among the oldest in the global oceans and natural upwelling processes in this eastern boundary current system bring CO2-rich water masses to the surface in coastal oceans during late spring-early fall months. We used a multiple linear regression (MLR) approach to generate predictive models using oxygen and temperature as proxy variables to reconstruct pH and carbonate saturation states in the Southern California Bight. The calibration data set included high-quality measurements of dissolved inorganic carbon, alkalinity, oxygen, temperature, salinity, and nutrients and was collected during a cruise from British Columbia to Baja California in May-June 2007. The resulting relationships predicting pH and aragonite and calcite saturation states (?) from oxygen and temperature data were robust, with r2 values >0.98 and root mean square errors of 0.020 (pH), 0.048 (?arag), and 0.075 (?calc). Predicted vs. measured ocean acidification conditions (i.e. pH, ?arag, and ?calc) matched very well for seven verification data sets collected between 2008 and 2010 during quarterly CalCOFI cruises in the Southern California Bight and during several sampling dates on an Ensenada transect occupied several times between 2006 and 2010. Over sub-decadal time scales, these predictive models provide a valuable tool for reconstructing historical time-series of ocean acidification conditions in the California Current Ecosystem where historical inorganic carbon measurements are scarce. Reconstructed pH and saturation state values based on CalCOFI oxygen and temperature data for all cruises between 2005 and 2010 reveal a seasonal cycle in the upper water column, with higher pH and ? values present during the winter cruises, and stronger gradients including much lower pH and ? values during spring through fall cruises. Deeper in the water column (~300 m), conditions are more stable throughout the annual cycle, with consistently low pH, undersaturation with respect to aragonite, and calcite saturation values <1.5. These predictive relationships can also be used to improve the performance of models used to nowcast and forecast ocean acidification in eastern boundary current systems like the California Current System.

Alin, S. R.; Feely, R. A.; Dickson, A. G.; Hernandez-Ayon, J. M.; Juranek, L. W.; Ohman, M. D.; Goericke, R.

2010-12-01

84

Assessment of the Current Status of the California Spotted Owl, with Recommendations for Management  

E-print Network

on the northern spotted owl throughout its range. Negotiations began shortly thereafter to undertake an assessmentChapter 1 Assessment of the Current Status of the California Spotted Owl, with Recommendations Owl Assessment Team Steer- ing Committee, with members representing several State of California

Standiford, Richard B.

85

Application of a data-assimilative regional ocean modeling system for assessing California Current System ocean conditions, krill, and juvenile rockfish interannual variability  

NASA Astrophysics Data System (ADS)

be robust and informative, marine ecosystem models and assessments require parameterized biophysical relationships that rely on realistic water column characteristics at appropriate spatial and temporal scales. We examine how hydrographic properties off California from 1990 through 2010 during late winter and spring correspond to krill and juvenile rockfish (Sebastes spp.) abundances. We evaluated coherence among temperature, salinity, depth of 26.0 potential density isopycnal, and stratification strength at regionally and monthly time scales derived from shipboard and mooring observations, and a data-assimilative Regional Ocean Model System reanalysis. The reanalysis captures spatiotemporal physical variability of coastal ocean conditions in winter and spring months and elucidates mechanisms connecting the spatial and temporal upwelling and transport dynamics on observed krill and rockfish abundances in spring. This provides evidence for a mechanistic connection between the phenology of upwelling in the California Current System and seasonal development of the shelf ecosystem.

Schroeder, Isaac D.; Santora, Jarrod A.; Moore, Andrew M.; Edwards, Christopher A.; Fiechter, Jerome; Hazen, Elliott L.; Bograd, Steven J.; Field, John C.; Wells, Brian K.

2014-08-01

86

Ecosystems  

NSDL National Science Digital Library

This lesson plan is part of the DiscoverySchool.com lesson plan library for grades 6-8. It focuses on biodiversity within ecosystems and within species. Students visit a local area and collect leaves to demonstrate how diverse life can exist within a small area. Included are objectives, materials, procedures, discussion questions, evaluation ideas, suggested readings, and vocabulary. There are videos available to order which complement this lesson, an audio-enhanced vocabulary list, and links to teaching tools for making custom quizzes, worksheets, puzzles and lesson plans.

2007-12-12

87

Benthic production and processes off Baja California, northwest Africa and Peru: a classification of benthic subsystems in upwelling ecosystems  

SciTech Connect

Estimates of the standing stocks, secondary production and metabolism of the benthos have been compared in the coastal upwelling ecosystems off northwest Africa, Baja California, and southern Peru. Northwest Africa is characterized by shelf break upwelling and as a result standing stocks, macrobenthic production and sediment organic matter are highest out at the shelf-slope boundary. Sediment microbial activity and biomass on the other hand are highest nearshore in the dynamic zone where aeolian silt and sand are being blown into the sea from the Sahara Desert. Baja California is dominated by the red crab, Pleuroncodes planipes, having high rates of growth and metabolic utilization of organic matter, both on bottom and in the water. Peru benthos and metabolism are very different from the above areas because of the low oxygen concentrations in the bottom water. Organic matter is far higher in the sediment and heterotrophic metabolism is principally anaerobic rather than aerobic. A normal offshore benthic fauna is replaced by a mat of sulfur bacteria with unknown production and metabolic rates. Benthic subsystems in upwelling ecosystems can be placed in two categories: those overloaded with organic matter, depleted of oxygen and dominated by sulfate reduction and those that are not overloaded and remain aerobic. Peru and southwest Africa typify overloaded systems whereas NW Africa and Baja California are examples of aerobic systems. Although benthic metabolism and ionorganic nutrient regeneration are high in both types of subsystems, all upwelling ecosystems, with their dynamic open boundaries, export organic particulate matter and import inorganic nutrients at rates that are far in excess of that consumed or produced by benthic metabolism. 42 refs., 7 figs., 8 tabs.

Rowe, G.T.

1983-01-01

88

SAFRR tsunami scenario: impacts on California ecosystems, species, marine natural resources, and fisheries: Chapter G in The SAFRR (Science Application for Risk Reduction) Tsunami Scenario  

USGS Publications Warehouse

We evaluate the effects of the SAFRR Tsunami Scenario on Californias ecosystems, species, natural resources, and fisheries. We discuss mitigation and preparedness approaches that can be useful in Tsunami planning. The chapter provides an introduction to the role of ecosystems and natural resources in tsunami events (Section 1). A separate section focuses on specific impacts of the SAFRR Tsunami Scenario on Californias ecosystems and endangered species (Section 2). A section on commercial fisheries and the fishing fleet (Section 3) documents the plausible effects on Californias commercial fishery resources, fishing fleets, and communities. Sections 2 and 3 each include practical preparedness options for communities and suggestions on information needs or research. Our evaluation indicates that many low-lying coastal habitats, including beaches, marshes and sloughs, rivers and waterways connected to the sea, as well as nearshore submarine habitats will be damaged by the SAFRR Tsunami Scenario. Beach erosion and complex or high volumes of tsunami-generated debris would pose major challenges for ecological communities. Several endangered species and protected areas are at risk. Commercial fisheries and fishing fleets will be affected directly by the tsunami and indirectly by dependencies on infrastructure that is damaged. There is evidence that in some areas intact ecosystems, notably sand dunes, will act as natural defenses against the tsunami waves. However, ecosystems do not provide blanket protection against tsunami surge. The consequences of ecological and natural resource damage are estimated in the millions of dollars. These costs are driven partly by the loss of ecosystem services, as well as cumulative and follow-on impacts where, for example, increased erosion during the tsunami can in turn lead to subsequent damage and loss to coastal properties. Recovery of ecosystems, natural resources and fisheries is likely to be lengthy and expensive. Preparedness is key to enhancing resilience to ecological impacts.

Brosnan, Deborah; Wein, Anne; Wilson, Rick

2014-01-01

89

Assessing Impacts of Climate Variability and Change on the Agro-ecosystems in California and Southwestern United States  

NASA Astrophysics Data System (ADS)

Climate variability and change affects natural and managed ecosystems, namely agriculture and rangelands, and the services they offer such as food, fiber, energy, fresh water, etc. we derive from them are among the highest concerns in quantifying the potential consequences of anthropogenic climate change. These impacts are expected to be ecosystem and region specific, thus requiring climate information at greater spatial and temporal resolution offered by the global climate models. In this study we are using a combination of climate downscaling and regional climate models in conjunction with ecosystem models to assess the impact of climate variability and change on the natural and managed ecosystems in California and Southwest region of the United States. In an attempt to generate reliable assessments of the impact of regional climate variability and change on the agro-ecosystems in the region, we have designed an impact assessment study in which multiple Regional Climate Models (RCMs) are used to develop downscaled climate information to in turn drive ecosystem models. We develop the climate scenarios for the region based on a combination of dynamical and statistical approaches. We evaluate the efficacy of the climate scenarios in hindcast mode against available historical observation records to build confidence in their future climate projections. We then use the derived climate information in the ecosystem models to assess how these ecosystems will function under the projected climate conditions. We will present some early results from the evaluation of three regional climate models in a long-term hindcast experiments, the fundamental step before performing regional climate projection. Model variables needed by agro-ecosystem models, daily precipitation and temperature extremes, from individual models and their ensembles, are being evaluated against the National Weather Service observation network and the global gridded analyses from NCEP. We also compare direct RCM simulations with a hybrid dynamical-statistical downscaling approach in order to expand our understanding of the limitations and strengths of various plausible approaches to generating high-resolution climate projections for agroecosystem impact analyses. The combination of Earth observations with model runs provides great opportunities for practical assessment of climate impacts at regional scales.

Kafatos, M.; Asrar, G. R.; El-Askary, H. M.; Hatzopoulos, N.; Hayhoe, K.; Kim, J.; Ziska, L.; Medvigy, D.; Prasad, A. K.; Tremback, C.; Walko, R. L.

2011-12-01

90

AUSTRONESIAN TAIWAN: CURRENT STRATEGY FOR A CALIFORNIA DIGITAL LIBRARY PUBLICATION  

Microsoft Academic Search

Austronesian Taiwan: Linguistics, History, Ethnology, and Prehistory recently edited by David Blundell, published by the Phoebe A. Hearst Museum of Anthropology, University of California, Berkeley, is a comprehensive work tracing the studies on the indigenous peoples in Taiwan known as Austronesian-speakers. 3 Presently David Blundell and Jeanette Zerneke are working on an e-publication based on the data and concepts presented

David Blundell; Jeanette Zerneke

91

The Foundations and Current Impact of California's Proposition 227.  

ERIC Educational Resources Information Center

California's Proposition 227 requires that all children be taught English by being taught in English. This proposition, which basically outlaws bilingual education, is the newest chapter in the history of how non-English speaking and limited English proficient (LEP) students should be educated. After presenting the historical, social, political,

Purcell, John

92

CURRENT DISTRIBUTION OF THE FISHER, MARTES PENNANTI, IN CALIFORNIA  

Microsoft Academic Search

Wedescribe the 1989-1994 distribution of the fisher, Martes pennanti, in California based on the results of detection surveys that used either sooted track-plates or cameras. Fishers were detected in two regions of the state: the northwest and the southern Sierra Nevada. Despite considerable survey effort, neither fisher tracks nor photographs were collected in the area between Mt. Shasta and Yosemite

WILLIAM J. ZIELINSKI; THOMAS E. KUCERA; REGINALD H. BARRETT

93

Effects of Debris Flows on Stream Ecosystems of the Klamath Mountains, Northern California  

NASA Astrophysics Data System (ADS)

We examined the long-term effects of debris flows on channel characteristics and aquatic food webs in steep (0.04-0.06 slope), small (4-6 m wide) streams. A large rain-on-snow storm event in January 1997 resulted in numerous landslides and debris flows throughout many basins in the Klamath Mountains of northern California. Debris floods resulted in extensive impacts throughout entire drainage networks, including mobilization of valley floor deposits and removal of vegetation. Comparing 5 streams scoured by debris flows in 1997 and 5 streams that had not been scoured as recently, we determined that debris-flows decreased channel complexity by reducing alluvial step frequency and large woody debris volumes. Unscoured streams had more diverse riparian vegetation, whereas scoured streams were dominated by dense, even-aged stands of white alder (Alnus rhombiflia). Benthic invertebrate shredders, especially nemourid and peltoperlid stoneflies, were more abundant and diverse in unscoured streams, reflecting the more diverse allochthonous resources. Debris flows resulted in increased variability in canopy cover, depending on degree of alder recolonization. Periphyton biomass was higher in unscoured streams, but primary production was greater in the recently scoured streams, suggesting that invertebrate grazers kept algal assemblages in an early successional state. Glossosomatid caddisflies were predominant scrapers in scoured streams; heptageniid mayflies were abundant in unscoured streams. Rainbow trout (Oncorhynchus mykiss) were of similar abundance in scoured and unscoured streams, but scoured streams were dominated by young-of-the-year fish while older juveniles were more abundant in unscoured streams. Differences in the presence of cold-water (Doroneuria) versus warm-water (Calineuria) perlid stoneflies suggest that debris flows have altered stream temperatures. Debris flows have long-lasting impacts on stream communities, primarily through the cascading effects of removal of riparian vegetation. Because debris flow frequency increases following road construction and timber harvest, the long-term biological effects of debris flows on stream ecosystems, including anadromous fish populations, needs to be considered in forest management decisions.

Cover, M. R.; Delafuente, J. A.; Resh, V. H.

2006-12-01

94

Modelling soil C sequestration in spruce forest ecosystems along a Swedish transect based on current conditions  

Microsoft Academic Search

The change of current pools of soil C in Norway spruce ecosystems in Sweden were studied using a process-based model (CoupModel).\\u000a Simulations were conducted for four sites representing different regions covering most of the forested area in Sweden and\\u000a representing annual mean temperatures from 0.7C to 7.1C. The development of both tree layer and field layer (understory)\\u000a was simulated during

Magnus Svensson; Per-Erik Jansson; Dan Berggren Kleja

2008-01-01

95

Comparison of Current and Historical Rates of Ecosystem Carbon Accumulation in a Northern Alberta Peatland  

NASA Astrophysics Data System (ADS)

As part of Fluxnet-Canada, we have been investigating the environmental controls on net ecosystem carbon dioxide exchange using the eddy covariance technique in a moderately rich (treed) fen in northern Alberta, Canada. In addition, integrated CO2 fluxes were compared to carbon stock measurements and rates of peat accumulation. The total ecosystem carbon stock was 52,669 g C m-2 with the vast majority (52,129) accumulated in peat over a 2 meter depth. The basal age for the peat was 2210 50 years before present. The above-ground carbon stock in the two tree species was 226 g C m-2. The oldest Picea mariana trees were aged at 135 years, and they showed a rapid increase in basal area increment starting about 65 years ago that peaked at rates of 2 cm2 yr-1 about 40 years ago. The Larix laricina trees became established approximately 45 years ago and currently have a basal area increment of 3 to 4 cm2 yr-1, much higher than the current rates (0.5 cm2 yr-1) observed for Picea mariana. The rates of peat accumulation were determined on 210Pb-dated cores. Over the last 70 years the peat gained an average of 113 12 g C m-2 yr-1. This was similar to net ecosystem production measured by eddy covariance (95 and 210 g C m-2 yr-1) over the last two years. Variation in annual net ecosystem production was associated with shifts in weather and growing season length. Current and recent historical rates of carbon accumulation were quite consistent despite significant variation in tree species growth and successional changes in this peatland over the last 70 years.

Syed, K. H.; Flanagan, L. B.; Carlson, P. J.; Glenn, A. J.; Ponton, S.

2005-12-01

96

A multi-scale analysis of dynamic optical signals in a Southern California chaparral ecosystem: A comparison of field, AVIRIS and MODIS data  

Microsoft Academic Search

Using field data, Airborne Visible Infrared Imaging Spectrometer (AVIRIS) imagery, and Moderate-Resolution Imaging Spectroradiometer (MODIS) data, a multi-scale analysis of ecosystem optical properties was performed for Sky Oaks, a Southern California chaparral ecosystem in the spectral network (SpecNet) and FLUXNET networks. The study covered a 4-year period (20002004), which included a severe drought in 2002 and a subsequent wildfire in

Yufu Cheng; John A. Gamon; David A. Fuentes; Zhiyan Mao; Daniel A. Sims; Hong-lie Qiu; Helen Claudio; Alfredo Huete; Abdullah F. Rahman

2006-01-01

97

Prototyping global Earth System Models at high resolution: Representation of climate, ecosystems, and acidification in Eastern Boundary Currents  

NASA Astrophysics Data System (ADS)

The world's major Eastern Boundary Currents (EBC) such as the California Current Large Marine Ecosystem (CCLME) are critically important areas for global fisheries. Computational limitations have divided past EBC modeling into two types: high resolution regional approaches that resolve the strong meso-scale structures involved, and coarse global approaches that represent the large scale context for EBCs, but only crudely resolve only the largest scales of their manifestation. These latter global studies have illustrated the complex mechanisms involved in the climate change and acidification response in these regions, with the CCLME response dominated not by local adjustments but large scale reorganization of ocean circulation through remote forcing of water-mass supply pathways. While qualitatively illustrating the limitations of regional high resolution studies in long term projection, these studies lack the ability to robustly quantify change because of the inability of these models to represent the baseline meso-scale structures of EBCs. In the present work, we compare current generation coarse resolution (one degree) and a prototype next generation high resolution (1/10 degree) Earth System Models (ESMs) from NOAA's Geophysical Fluid Dynamics Laboratory in representing the four major EBCs. We review the long-known temperature biases that the coarse models suffer in being unable to represent the timing and intensity of upwelling-favorable winds, along with lack of representation of the observed high chlorophyll and biological productivity resulting from this upwelling. In promising contrast, we show that the high resolution prototype is capable of representing not only the overall meso-scale structure in physical and biogeochemical fields, but also the appropriate offshore extent of temperature anomalies and other EBC characteristics. Results for chlorophyll were mixed; while high resolution chlorophyll in EBCs were strongly enhanced over the coarse resolution ESM, they were still considerably lower than observed values. In terms of representation of large scale circulation and biogeochemistry, results were also mixed, with the high resolution prototype addressing some, but not all, of the biases in the coarse resolution ESM. While considerable work remains to understand the current strengths and weaknesses of the high resolution ESM and continue to improve fidelity, this work is a major step forward in demonstrating the added value of high resolution in global ESMs and represents a fundamental leap forward towards both ecological forecasting and long term projection of climate, ecosystem, and acidification baselines and sensitivity.

Dunne, J. P.; John, J. G.; Stock, C. A.

2013-12-01

98

Ecosystem services Bridging ecology, economy and social sciences Humanenvironmental systems are challenged by current and  

E-print Network

Editorial Ecosystem services ­ Bridging ecology, economy and social sciences Human. Ecosystem degradation, resource depletion, social conflicts or economic up- and downturns are in everyone adaptive ecosystems. This requires integrative and innovative adaptive management approaches to meet

Vermont, University of

99

Using sensitive montane amphibian species as indicators of hydroclimatic change in meadow ecosystems of the Sierra Nevada, California  

NASA Astrophysics Data System (ADS)

Climate change can affect sensitive species and ecosystems in many ways, yet sparse data and the inability to apply various climate models at functional spatial scales often prevents relevant research from being utilized in conservation management plans. Climate change has been linked to declines and disturbances in a multitude of species and habitats, and in California, one of the greatest climatic concerns is the predicted reduction in mountain snowpack and associated snowmelt. These decreases in natural storage of water as snow in mountain regions can affect the timing and variability of critical snowmelt runoff periodsimportant seasonal signals that species in montane ecosystems have evolved life history strategies aroundleading to greater intra-annual variability and diminished summer and fall stream flows. Although many species distribution models exist, few provide ways to integrate continually updated and revised Global Climate Models (GCMs), hydrologic data unique to a watershed, and ecological responses that can be incorporated into conservation strategies. This study documents a novel and applicable method of combining boosted regression tree (BRT) modeling and species distributions with hydroclimatic data as a potential management tool for conservation. Boosted regression trees are suitable for ecological distribution modeling because they can reduce both bias and variance, as well as handle sharp discontinuities common in sparsely sampled species or large study areas. This approach was used to quantify the effects of hydroclimatic changes on the distribution of key riparian-associated amphibian species in montane meadow habitats in the Sierra Nevada at the sub-watershed level. Based on modeling using current species range maps in conjunction with three climate scenarios (near, mid, and far), extreme range contractions were observed for all sensitive species (southern long-toed salamander, mountain yellow-legged frog, Yosemite toad) by the year 2100. Among many environmental and hydroclimatic variables used in the model, snowpack and snowmelt (runoff) variables were consistently among the most informative in predicting species occupancy. Few sub-watersheds contained greater than 50% probability of species occupancy throughout the modeled time period; however several core areas were identified as more resilient to climate change for each species. There was overlap among species in areas that were predicted to remain hydroclimatically stable, particularly in sub-watersheds that contain high meadow density. Quantifying these areas of habitat stability, or "resiliency", may ultimately be the most useful outcome of BRT modeling, with the flexibility to utilize multiple GCMs at varying scales. Ultimately managers need to consider both short term and long term conservation goals by identifying and protecting suitable habitat areas most resilient to climate change to give multiple species the best chance to persist. This approach provides a unique tool for conservation management which can be easily applied to a variety of data and species, and provides useful knowledge at both near and long term time scales.

Peek, R.; Viers, J.; Yarnell, S. M.

2012-12-01

100

Tracking Progress Last updated 6/2/2014 Current and Expected Energy From Coal for California 1  

E-print Network

Tracking Progress Last updated 6/2/2014 Current and Expected Energy From Coal for California 1 Actual and Expected Energy From Coal for California - Overview Electricity supplies from existing coal in California load during 2012. A little over 93 percent of this coal-based energy came from power plants

101

Biogenic sedimentation beneath the California Current system for the past 30 kyr and its paleoceanographic significance  

USGS Publications Warehouse

A north-south transect of 17 cores was constructed along the eastern boundary of the California Current system from 33?? to 42?? N to investigate the changes in biogenic sedimentation over the past 30 kyr. Percentages and mass accumulation rates of CaCO3, Corg, and biogenic opal were assembled at 500 to 1000 years/sample to provide relatively high resolution. Time-space maps reveal a complex pattern of changes that do not follow a simple glacial-interglacial two-mode model. Biogenic sedimentation shows responses that are sometimes time-transgressive and sometimes coeval, and most of the responses show more consistency within a limited geographic area than any temporal consistency. Reconstructed conditions during late oxygen isotope stage 3 were more like early Holocene conditions than any other time during the last 30 kyr. Coastal upwelling and productivity during oxygen isotope stage 3 were relatively strong along the central California margin but were weak along the northern California margin. Precipitation increased during the last glacial interval in the central California region, and the waters of the southern California margin had relatively low productivity. Productivity on the southern Oregon margin was relatively low at the beginning of the last glacial interval, but by about 20 ka, productivity in this area significantly increased. This change suggests that the center of the divergence of the West Wind Drift shifted south at this time. The end of the last glacial interval was characterized by increased productivity in the southern California margin and increased upwelling along the central California margin but upwelling remained weak along the northern California margin. A sudden (<300 years) decrease in CaCO3, Corg, and biogenic opal occurred at 13 ka. The changes suggest a major reorientation of the atmospheric circulation in the North Pacific and western North America and the establishment of a strong seasonality in the central California region. A carbonate preservation event occurred at 10 ka that appears to reflect the uptake of CO2 by the terrestrial biosphere as the northern latitudes were reforested following retreat of the glaciers. The Holocene has been a period of relatively high productivity in the southern California margin, relatively strong coastal upwelling along the central California margin, relatively weak upwelling along the northern California margin, and the northward migration of the divergence zone of the West Wind Drift.

Gardner, J.V.; Dean, W.E.; Dartnell, P.

1997-01-01

102

Modeling phytoplankton growth rates and chlorophyll to carbon ratios in California coastal and pelagic ecosystems  

Microsoft Academic Search

To understand and quantify plankton community dynamics in the ocean, high-resolution models are needed to capture the temporal and spatial variations of physical, biological, and biogeochemical processes. However, ecosystem models often fail to agree with observations. This failure can be due to inadequacies in the data and\\/or inadequacies in the model formulation and parameterization. Here we parameterize and optimize a

Qian P. Li; Peter J. S. Franks; Michael R. Landry; Ralf Goericke; Andrew G. Taylor

2010-01-01

103

ORGANIC POLLUTANT DEPOSITION TO THE SIERRA NEVADA (CALIFORNIA, USA) SNOWPACK AND ASSOCIATED LAKE AND STREAM ECOSYSTEM  

EPA Science Inventory

High elevation ecosystems in the western USA and Canada are receiving deposition of persistent organic pollutants (POPs) that presumably originate in the USA as well as outside its borders. In April 1992 we obtained paired snowpack samples from each of two watersheds located in t...

104

The area requirements of an ecosystem service: crop pollination by native bee communities in California  

Microsoft Academic Search

Managing ecosystem services is critical to human survival, yet we do not know how large natural areas must be to support these services. We investigated how crop pollination services provided by native, unmanaged, bee communities varied on organic and conventional farms situated along a gradient of isolation from natural habitat. Pollination services from native bees were significantly, positively related to

Claire Kremen; Neal M. Williams; Robert L. Bugg; John P. Fay; Robin W. Thorp

2004-01-01

105

Hypoxia in high-resolution sediment records: reconstructing the California Current Oxygen Minimum Zone on multi-decadal timescales  

NASA Astrophysics Data System (ADS)

The recent deglaciation event is an ideal laboratory to study the rapid expansion of Oxygen Minimum Zones (OMZs) and the ecological ramifications of such events. Santa Barbara Basin (SBB) sediments are high-resolution archives of seafloor ecosystems, recording both global-scale climate and regional-scale hydrographic events. Seafloor hypoxia in the California Current Ecosystem (CCE) is caused by OMZs in intermediate water depths (300-1200 m), and produces striking evidence in SBB sediment archives. We construct a vertical transect of proxies across SBB (34 15'N, 119 45'W) using a core from 418 m water depth (MV0811-15JC), and previously investigated cores from 440 m (MD02-2504) and 570 m (MD02-2503) water depths. Benthic foraminiferal assemblages and planktonic ?18O proxies were quantified at all three depths, while benthic invertebrate communities were quantified in the shallowest core at a 1-cm resolution (~10 years). This high-resolution invertebrate record provides a window into rapid, decadal-scale environmental change in continental margin ecosystems. Seafloor biodiversity is highly variable on 10-10^4 year timescales (across Protist, Mollusc, Arthropod and Echinoderm taxonomic groups), and is tightly coupled to both regional-scale environmental change and global-scale climate events. Additionally, we provide evidence that strongly hypoxic waters shoaled to <300 m water depth at Termination 1A (14.7 ka), implying that the upper boundary of the regional OMZ can expand >150 m on multi-decadal timescales. These data confirm that OMZs have rapidly expanded in the CCE during previous events of global-scale warming, and that continental margin seafloor biodiversity is variable on previously undescribed timescales.

Moffitt, S. E.; Hill, T. M.

2012-12-01

106

Positive Effects of Non-Native Grasses on the Growth of a Native Annual in a Southern California Ecosystem  

PubMed Central

Fire disturbance is considered a major factor in the promotion of non-native plant species. Non-native grasses are adapted to fire and can alter environmental conditions and reduce resource availability in native coastal sage scrub and chaparral communities of southern California. In these communities persistence of non-native grasses following fire can inhibit establishment and growth of woody species. This may allow certain native herbaceous species to colonize and persist beneath gaps in the canopy. A field manipulative experiment with control, litter, and bare ground treatments was used to examine the impact of non-native grasses on growth and establishment of a native herbaceous species, Cryptantha muricata. C. muricata seedling survival, growth, and reproduction were greatest in the control treatment where non-native grasses were present. C. muricata plants growing in the presence of non-native grasses produced more than twice the number of flowers and more than twice the reproductive biomass of plants growing in the treatments where non-native grasses were removed. Total biomass and number of fruits were also greater in the plants growing in the presence of non-native grasses. Total biomass and reproductive biomass was also greater in late germinants than early germinants growing in the presence of non-native grasses. This study suggests a potential positive effect of non-native grasses on the performance of a particular native annual in a southern California ecosystem. PMID:25379790

Pec, Gregory J.; Carlton, Gary C.

2014-01-01

107

Current Development at the Southern California Earthquake Data Center (SCEDC)  

Microsoft Academic Search

Over the past year, the SCEDC completed or is near completion of three featured projects: Station Information System (SIS) Development: The SIS will provide users with an interface into complete and accurate station metadata for all current and historic data at the SCEDC. The goal of this project is to develop a system that can interact with a single database

V. L. Appel; R. W. Clayton

2005-01-01

108

Regulatory Constraints to Carbon Sequestration in Terrestrial Ecosystems and Geologic Formations: A California Perspective  

Microsoft Academic Search

Carbon sequestration in terrestrialecosystems and geologic formations providesa significant opportunity for California toaddress global climate change. The physicalsize of its resources (e.g., forests,agriculture, soils, rangeland, and geologicformations) and the expertise in Californiaprovides a substantial foundation fordeveloping carbon sequestration activities.Furthermore, the co-benefits of carbonsequestration such as improved soil andwater quality, restoration of degradedecosystems, increased plant and cropproductivity, and enhanced oil

Edward Vine

2004-01-01

109

RANGE EXPANSION AND TROPHIC INTERACTIONS OF THE JUMBO SQUID, DOSIDICUS GIGAS, IN THE CALIFORNIA CURRENT  

Microsoft Academic Search

Although jumbo squid (Dosidicus gigas) have been oc- casional visitors to the California Current over the last century, their abundance and distribution increased be- tween 2002 and 2006. We report several time series of jumbo squid relative abundance from commercial and recreational fisheries as well as resource surveys and food habits studies. To evaluate the trophic relationships of jumbo squid,

JOHN C. FIELD; KEN BALTZ; A. JASON PHILLIPS

110

Evolution of chemical, biological, and physical water properties in the northern California Current in 2005  

E-print Network

Evolution of chemical, biological, and physical water properties in the northern California Current-integrated local wind stress but consistent in timing with ``remote'' forcing of water properties in this region. Cochlan, R. Kudela, K. Bruland, and C. Trick (2006), Evolution of chemical, biological, and physical water

Hickey, Barbara

111

The Current State of Quality of Care Measurement in the California Department of Corrections and Rehabilitation  

Microsoft Academic Search

The quality of health care in prisons is lacking in many states. In particular, the California Department of Corrections and Rehabilitation (CDCR) is in the midst of an extreme legal remedy to address problems related to access to and quality of care; it now operates under the direction of a federally appointed receiver for medical care. To understand the current

Stephanie S. Teleki; Cheryl L. Damberg; Rebecca Shaw; Liisa Hiatt; Brie Williams; Terry E. Hill; Steven M. Asch

2011-01-01

112

The State of the California Current in 1999-2000: Forward to a New Regime?  

NASA Technical Reports Server (NTRS)

Following an extended absence, the reintroduction of ocean color sensors to space in the mid to late 1990's provided an invaluable opportunity for evaluating the biological impact of the 1997-99 El Nino/La Nina events in the California Current System (CCS).

DiGiacomo, P.

2000-01-01

113

Patterns of covariability among California Current chinook salmon, coho salmon, Dungeness crab, and physical oceanographic conditions  

Microsoft Academic Search

One of the primary motivations for the GLOBEC NEP program was the apparent inverse relationship between the increase in salmon populations in the Gulf of Alaska since the mid-1970s and concurrent declines in salmon populations in the California Current. The increase in abundance of some salmon species in the Gulf of Alaska can be plausibly explained based on mechanisms involving

L. W Botsford; C. A Lawrence

2002-01-01

114

Satellite measurements of chlorophyll distribution during spring 2005 in the California Current  

E-print Network

Satellite measurements of chlorophyll distribution during spring 2005 in the California Current; published 2 September 2006. [1] Eight years of satellite data quantify spring 2005 surface chlorophyll ) north of 45°N. Positive chlorophyll anomalies dominate from $40°N to 27°N during this period. Strongest

Thomas, Andrew

115

Interannual variability in chlorophyll concentrations in the Humboldt and California Current Systems  

E-print Network

Interannual variability in chlorophyll concentrations in the Humboldt and California CurrentWiFS data provide the first systematic comparison of 10 years (1997­2007) of chlorophyll interannual occur in austral summers of 2002­2003, 2003­2004. Relationships of chlorophyll anomalies to forcing

Thomas, Andrew

116

234Th:238U disequilibria within the California Current  

Microsoft Academic Search

Profiles of dissolved and particulate 234Th were determined at several stations within the Cali- fornia Current. Modeling of the disequilibria between the 234Th and 23aU within the surface waters provides for estimates of the residence time of dissolved thorium with respect to particle scavenging (TP varies from 6 to 50 days), the particle residence time (TP varies from 2 to

KENNETH H. COALE; KENNETH W. BRULAND

1985-01-01

117

The impact of antecedent fire area on burned area in southern California coastal ecosystems.  

PubMed

Frequent wildfire disasters in southern California highlight the need for risk reduction strategies for the region, of which fuel reduction via prescribed burning is one option. However, there is no consensus about the effectiveness of prescribed fire in reducing the area of wildfire. Here, we use 29 years of historical fire mapping to quantify the relationship between annual wildfire area and antecedent fire area in predominantly shrub and grassland fuels in seven southern California counties, controlling for annual variation in weather patterns. This method has been used elsewhere to measure leverage: the reduction in wildfire area resulting from one unit of prescribed fire treatment. We found little evidence for a leverage effect (leverage = zero). Specifically our results showed no evidence that wildfire area was negatively influenced by previous fires, and only weak relationships with weather variables rainfall and Santa Ana wind occurrences, which were variables included to control for inter-annual variation. We conclude that this is because only 2% of the vegetation burns each year and so wildfires rarely encounter burned patches and chaparral shrublands can carry a fire within 1 or 2 years after previous fire. Prescribed burning is unlikely to have much influence on fire regimes in this area, though targeted treatment at the urban interface may be effective at providing defensible space for protecting assets. These results fit an emerging global model of fire leverage which position California at the bottom end of a continuum, with tropical savannas at the top (leverage = 1: direct replacement of wildfire by prescribed fire) and Australian eucalypt forests in the middle (leverage ~ 0.25). PMID:23064248

Price, Owen F; Bradstock, Ross A; Keeley, Jon E; Syphard, Alexandra D

2012-12-30

118

Quantification of Lateral Carbon Flux in a Chaparral Ecosystem in Southern California Alessandra Rossi, Walter Oechel, Patrick Murphy  

NASA Astrophysics Data System (ADS)

The lateral transport of carbon is a horizontal transfer of carbon away from the area it was withdrawn from the atmosphere (Ciais et al. 2006). Research regarding horizontal C transport has received much less attention in arid and semi-arid regions compared to other types of ecosystems. Drylands represent around 47.2% (Lal 2004) of the global terrestrial area and despite characterized by relatively low carbon flux, drylands comprise approximately 15.5% of the world's total soil organic carbon (SOC) (Eswaran et al. 2000, Schlesinger, 1991). Moreover, these dry areas contain at least as much soil inorganic carbon (SIC) as SOC (Eswaran et al. 2000). Therefore, these areas potentially have a large contribution to the global carbon budget and they deserve attention. A long-term observation of CO2 flux with the eddy covariance technique has been conducted since 1997 at Sky Oaks Field Station in Southern California, an area of Mediterranean climate at the climatic transition between semiarid area and desert. The long term record of CO2 flux showed the area has been a sink of CO2 of over -0.2 kgCm-2yr-1. In addition to evaluating vertical carbon fluxes, we initiated a project to evaluate lateral carbon transports using litter traps, sediment fences and two small weirs adjacent to the eddy covariance site. Preliminary results indicate that the lateral transfer of C in the area may offset the vertical influx to this shrub ecosystem. However, it is still necessary to develop the methodology to compare vertical carbon flux and the lateral carbon fluxes more accurately.

Rossi, A.; Oechel, W. C.; Murphy, P.

2013-12-01

119

The impact of El Nino on island ecosystems in the gulf of California  

SciTech Connect

The El Nino event of 1992-1993 had significant effects on all functional levels of the terrestrial food web of islands in the Gulf of California. These islands are normally very dry; however, during this El Nino event, annual precipitation was nearly five times the median annual precipitation. This caused tremendous increases in plant cover and a significant rise in aerial arthropod abundance. At first, spiders benefited from increased productivity: in 1992, spiders increased to their highest densities in the three years of the study. However, in 1993, despite continued high plant cover and insect prey abundance, spider densities dropped precipitously. This decrease appears to be due to the emergence of numerous parasitoid wasps that formed a hidden trophic influence. Wasps were ineffective at controlling spider densities during dry years due to the absence of their adult food, nectar and pollen from flowering land plants. Abundant flowers during El Nino allowed the wasp population to increase and reproduce successfully.

Polis, G.A.; Hurd, S.D. [Vanderbilt Univ., Nashville, TN (United States)

1995-09-01

120

Spatial and interannual variability in mesoscale circulation in the northern California Current System  

Microsoft Academic Search

We used wavelet analyses of sea surface height (SSH) from >13 years of satellite altimeter data to characterize the variability in mesoscale circulation in the northern California Current (35N49N) and explore the mechanisms of variability. We defined mesoscale circulation as features, such as eddies and filaments, which have 50- to 300-km length scales and 4- to 18-week temporal scales. Fluctuations

Julie E. Keister; P. Ted Strub

2008-01-01

121

Lagrangian studies of phytoplankton growth and grazing relationships in a coastal upwelling ecosystem off Southern California  

NASA Astrophysics Data System (ADS)

Experimental studies of phytoplankton growth and grazing processes were conducted in the coastal upwelling system off Point Conception, California to test the hypothesis that phytoplankton growth and grazing losses determine, to first order, the local dynamics of phytoplankton in the upwelling circulation. Eight experiments of 3-5 days each were conducted over the course of two cruises in May-June 2006 and April 2007 following the trajectories of satellite-tracked drifters. Rates of phytoplankton growth and microzooplankton grazing were determined by daily in situ dilution incubations at 8 depths spanning the euphotic zone. Mesozooplankton grazing was assessed by gut fluorescence analysis of animals collected from net tows through the euphotic zone. We compared directly the net rates of change observed for the ambient phytoplankton community to the net growth rates predicted from experimental determinations of each process rate. The resulting relationship accounted for 91% of the variability observed, providing strong support for the growth-grazing hypothesis. In addition, grazing by mesozooplankton was unexpectedly high and variable, driving a substantial positive to negative shift in phytoplankton net rate of change between years despite comparable environmental conditions and similar high growth rates and suggesting strong top-down control potential. The demonstrated agreement between net ambient and experimental community changes is an important point of validation for using field data to parameterize models. Data sets of this type may provide an important source of new information and rate constraints for developing better coupled biological-physical models of upwelling system dynamics.

Landry, Michael R.; Ohman, Mark D.; Goericke, Ralf; Stukel, Michael R.; Tsyrklevich, Kate

2009-12-01

122

Interannual variation in climate-potential net primary productivity relationships in differing ecosystems of California  

SciTech Connect

The seasonality and interannual variation in potential net primary production (NPP) were examined in differing vegetation types in California over three years of contrasting precipitation using co-registered maps of climate, vegetation, and 1km biweekly NDVI derived from high resolution satellite AVHRR data. Differences in seasonality of the vegetation types (annual grassland, chamise chaparral, deciduous oak woodland, and evergreen oak) were clearly evident and corresponded well to patterns observed in field studies. In years and locations having high precipitation the annual peak in NDVI occurred later in all vegetation classes. The annual sum of biweekly NDVI was correlated with annual precipitation in all vegetation types, although the slopes and intercepts of the regressions differed among types. Annual grassland showed the largest increase in sumNDVI per unit increase in total precipitation and most of the variation in grassland sumNDVI was explained by variation in autumn precipitation. In general the ratio of sumNDVI to annual precipitation was dependent on the temporal distribution of precipitation with respect to the long-term average pattern. Published relationships between precipitation and NPP were used to develop equations relating annual NDVI sum to NPP.

Koch, G.W.; Randerson, J.T. (Stanford Univ. Carnegie Institution of Plant Biology, CA (United States))

1994-06-01

123

Ecosystem response to regulatory and management actions: the southern California experience in long-term monitoring.  

PubMed

Billions of dollars have been invested over the past 35 years in reducing pollutant emissions to coastal environments. Evaluation of the effectiveness of this investment is hampered by the lack of long-term consistent data. A rare opportunity exists in southern California to evaluate the effectiveness of management actions by analyzing long-term monitoring of effluent, sediment, benthos, and fish and comparing this trend data to periodic regional surveys of environmental condition. In this paper, we ask the question "have improvements in effluent quality in response to environmental regulation translated into improvements in the receiving environment?" Results indicate that management actions directed at reducing mass emissions from wastewater treatment plants (POTWs) have resulted in substantial improvement in aquatic communities. However, the magnitude and timing of response varies by indicator suggesting that use of multiple assessment endpoints is necessary to adequately interpret trends. Reductions in the effect of POTW effluent have allowed managers to shift resources to address other contaminant sources such as stormwater and resuspension of legacy pollutants. PMID:19329129

Stein, Eric D; Cadien, Donald B

2009-01-01

124

A Comparison between Value-Added School Estimates and Currently Used Metrics of School Accountability in California  

ERIC Educational Resources Information Center

This study compared a value-added approach to school accountability to the currently used metrics of accountability in California of Adequate Yearly Progress (AYP) and Academic Performance Index (API). Five-year student panel data (N?=?53,733) from 29 elementary schools in a large California school district were used to address the research

Fagioli, Loris P.

2014-01-01

125

Managing Peatland Ecosystem Services: Current UK Policy and Future Challenges in a Changing World  

Microsoft Academic Search

Sustainable peatland management has recently risen up the UK political agenda as links between peatland ecosystem services and key political priorities, such as rural livelihoods, agricultural production, biodiversity conservation, and carbon emissions, have become established. By adopting an ecosystem approach, something that has become internationally advocated through the Convention on Biological Diversity, to understanding the objectives and sustainability of UK

Stephen Whitfield; Mark Reed; Ken Thomson; Mike Christie; Lindsay C. Stringer; Claire H. Quinn; Russell Anderson; Andrew Moxey; Klaus Hubacek

2011-01-01

126

Modeling the yield potential of dryland canola under current and future climates in California  

NASA Astrophysics Data System (ADS)

Models predict that the climate of California will become hotter, drier and more variable under future climate change scenarios. This will lead to both increased irrigation demand and reduced irrigation water availability. In addition, it is predicted that most common Californian crops will suffer a concomitant decline in productivity. To remain productive and economically viable, future agricultural systems will need to have greater water use efficiency, tolerance of high temperatures, and tolerance of more erratic temperature and rainfall patterns. Canola (Brassica napus) is the third most important oilseed globally, supporting large and well-established agricultural industries in Canada, Europe and Australia. It is an agronomically useful and economically valuable crop, with multiple end markets, that can be grown in California as a dryland winter rotation with little to no irrigation demand. This gives canola great potential as a new crop for Californian farmers both now and as the climate changes. Given practical and financial limitations it is not always possible to immediately or widely evaluate a crop in a new region. Crop production models are therefore valuable tools for assessing the potential of new crops, better targeting further field research, and refining research questions. APSIM is a modular modeling framework developed by the Agricultural Production Systems Research Unit in Australia, it combines biophysical and management modules to simulate cropping systems. This study was undertaken to examine the yield potential of Australian canola varieties having different water requirements and maturity classes in California using APSIM. The objective of the work was to identify the agricultural regions of California most ideally suited to the production of Australian cultivars of canola and to simulate the production of canola in these regions to estimate yield-potential. This will establish whether the introduction and in-field evaluation of better-adapted canola varieties can be justified, and the potential value of a California canola industry both now and in the future. Winter annual crops like canola use rainfall in a Mediterranean climate like California more efficiently than spring or summer crops. Our results suggest that under current production costs and seed prices, dry farmed canola will have good potential in certain areas of the California. Canola yields decline with annual winter precipitation, however economically viable yields are still achieved at relatively precipitation levels (200 mm). Results from simulation, combined with related economic modeling (reported elsewhere) suggest that canola will be viable in a variety of production systems in the northern Sacramento Valley and some coastal locations, even under drier future climate scenarios. The in-field evaluation of Australian canola varieties should contribute to maintain or improving resource use efficiency and farm profitability.

George, N.; Kaffka, S.; Beeck, C.; Bucaram, S.; Zhang, J.

2012-12-01

127

SignsofAdaptationtoLocalpHConditionsacrossanEnvironmental Mosaic in the California Current Ecosystem  

E-print Network

, OR 97331, USA; Department of Biology, Stanford University, Hopkins Marine Station, Pacific Grove, CA 93950, and cell­cell adhesion, functional pathways important for maintaining homeostasis at low pH. We identify

Palumbi, Stephen

128

Pattern and persistence of a nearshore planktonic ecosystem off Southern California  

NASA Astrophysics Data System (ADS)

Three related data sets from a baseline environmental survey on the continental shelf at San Onofre, California, consisting of: (1) zooplankton pumped from discrete depths on transects between the 8- and 30-m contours, sampled from 1976 to 1980; (2) zooplankton from oblique net hauls on a transect from 8 to 100 m sampled at 2-week intervals for 1 y, 1978-1979; and (3) vertical profiles of temperature, nutrients and plant pigments corresponding closely in time and space to the oblique net hauls, are used to describe cross-shelf zooplankton abundance patterns, community composition, and seasonal and shorter-term variations in cross-shelf zonation and their relation to variations in physical and chemical measures. Of 15 taxa tested for multiyear average patterns, threethe copepods Acartia clausi and Oithona oculata, and barnacle larvaehad centers of abundance shoreward of the 30-m contour and near the bottom. No differences were detected in the cross-shelf pattern between San Onofre and a transect 12 km southeast. Throughout the year, nearshore and offshore assemblages were distinguishable, the change occurring at about the 30-m contour. The offshore one, represented by the copepods Calanus pacificus, Eucalanus californicus and Rhincalanus nasutus, occupied water having less chlorophyll and less near-surface nutrient, i.e. of more oceanic character. In spring and summer, most nearshore taxa shifted slightly seaward, leaving a third assemblage, characterized by a very high abundance of Acartia spp. copepodids and maximum abundances of A. clausi and O. oculata near the beach. Three upwelling episodes resulted in marked increases in chlorophyll and nutrients, but not in cross-shelf gradients of these properties, as were noted at most other times. Maximum disturbance of cross-shelf zooplankton zonation was observed during a wintertime intrusion of offshore surface water, but the zonation was never obliterated. Nearshore zooplankton patterns appear to be protected from dislocation by the shallow shelf and sustained by phytoplankton distributed in a manner peculiar to the nearshore zone. Typically, shallow nearshore waters were richer in chlorophyll and nutrients than offshore waters of the same depth. The cross-shelf chlorophyll and nutrient profiles, in turn, appear to result from increased eddy diffusion and nutrient recycling in shallow waters, perhaps augmented by longshore transport from quasi-permanent, local upwelling nodes.

Barnett, Arthur M.; Jahn, Andrew E.

1987-01-01

129

Environmental fate of fungicides and other current-use pesticides in a central California estuary  

USGS Publications Warehouse

The current study documents the fate of current-use pesticides in an agriculturally-dominated central California coastal estuary by focusing on the occurrence in water, sediment and tissue of resident aquatic organisms. Three fungicides (azoxystrobin, boscalid, and pyraclostrobin), one herbicide (propyzamide) and two organophosphate insecticides (chlorpyrifos and diazinon) were detected frequently. Dissolved pesticide concentrations in the estuary corresponded to the timing of application while bed sediment pesticide concentrations correlated with the distance from potential sources. Fungicides and insecticides were detected frequently in fish and invertebrates collected near the mouth of the estuary and the contaminant profiles differed from the sediment and water collected. This is the first study to document the occurrence of many current-use pesticides, including fungicides, in tissue. Limited information is available on the uptake, accumulation and effects of current-use pesticides on non-target organisms. Additional data are needed to understand the impacts of pesticides, especially in small agriculturally-dominated estuaries.

Smalling, Kelly L.; Kuivila, Kathryn M.; Orlando, James L.; Phillips, Bryn M.; Anderson, Brian S.; Siegler, Katie; Hunt, John W.; Hamilton, Mary

2013-01-01

130

CLIMATE CHANGE IMPACTS ON CALIFORNIA VEGETATION  

E-print Network

CLIMATE CHANGE IMPACTS ON CALIFORNIA VEGETATION: PHYSIOLOGY, LIFE HISTORY, AND ECOSYSTEM CHANGE A White Paper from the California Energy Commission's California Climate Change Center of the uncertainties with climate change effects on terrestrial ecosystems is understanding where transitions

131

An Extreme Expression of the California Current during the Holocene: New Evidence from the Washington Margin  

NASA Astrophysics Data System (ADS)

A multi-proxy bulk sedimentary geochemical and foraminiferal faunal study of a sediment core (TTN131-4 GC36; 4630'N, 12530'W, 1951m) from the continental slope off Washington State reveals millennial-scale variability in ocean circulation over the past 8000 years and offers a novel marine perspective on regional Holocene climate variability. Foraminiferal isotopes, faunal census data, and bulk sedimentary Corg, CaCO3 and trace metal concentrations were determined for GC36. Planktonic foraminiferal faunal records suggest cooler than present SSTs between 7 and 4.5 ka. Between 4.5 and 3 ky, benthic foraminifer ?18O and ?13C records display shifts towards more positive values (0.39 and 0.9, respectively), Corg increases, and sedimentary Re and U suggest a shift from less well oxygenated sedimentary conditions at 4 ka to more oxygenated sediments by 3.5 ka, an interpretation supported by benthic foraminifer assemblages. The Washington margin paleoceanographic data generally compliments previous studies from more southerly margin sites that suggest insolation-driven strengthening of the North Pacific High, resulting in a stronger California Current and increased regional coastal upwelling. This is expressed off the Oregon Margin as stronger upwelling and cooler SSTs as gyral waters are forced off shore. A reduction in the southward flow of the California Current and decreased upwelling has been proposed between 4.8 and 3.6 ka. Prior to ~ 4 ka, foraminiferal data and bulk sedimentary data support a stronger California Current System and coastal upwelling. Corg, however, displays an opposing interpretation that may be related to a change in preservation history. After ~ 4 ka planktonic foraminiferal assemblages and benthic foraminiferal data display increased variability, likely related to the weakening of the North Pacific high pressure system and the development of modern oceanographic and atmospheric circulation regimes.

Griffin, H.; Shevenell, A. E.; Hendy, I. L.; Emerson, S. R.

2008-12-01

132

Climatic impacts on phenology in chaparral- and coastal sage scrub-dominated ecosystems in southern California using MODIS-derived time series  

NASA Astrophysics Data System (ADS)

Remote sensing monitoring of vegetation phenology can be an important tool for detecting the impacts of climate change on whole ecosystem functioning at local to regional scales. This study elucidates climate-phenology relations and the changes occurring in the phenology of both chaparral and coastal sage scrub-dominated ecosystems in southern California. Whole ecosystem phenology is monitored for the period 2001-2012 using the Normalized Difference Vegetation Index (NDVI) and Enhanced Vegetation Index (EVI) derived from MODIS MOD13Q1. Changes in phenology are assessed through a comparison of the time series with temperature, precipitation, and Palmer Drought Severity Index (PDSI) data and by computing time series phenology metrics. Overall we find that the vegetation index values have fluctuated around a stable mean for vegetation types for the entire time period. However, interannual variability is high, likely due to annual variations in climate. The most significant statistical correlation in chaparral ecosystems were found between NDVI and PDSI, indicating that chaparral phenology is likely driven by drought and soil water deficit at the multi-monthly timescale. However, coastal sage scrub correlations were highest between NDVI and temperature + precipitation combined with no time lag. This reflects a more immediate response by these shallow rooted and deciduous species. The start of the growing season in both plant communities occurred early in rainy years, and later in years with lower PDSI (drought-associated). This suggests that future predicted climate change in southern California may cause increased interannual variability in chaparral phenology cycles, with early initiation of the growing season occurring in years following large rain events, and later initiation in drought years. Coastal sage scrub-dominated areas will be less influenced by lower frequency, long-term drought, but more immediately affected by discrete precipitation events and timing.

Willis, K. S.; Gillespie, T.; Okin, G. S.; MacDonald, G. M.

2013-12-01

133

Productividad primaria del fitoplancton en la zona euftica del Sistema de la Corriente de California estimada mediante imgenes del CZCS Phytoplankton primary productivity in the euphotic zone of the California Current System estimated from CZCS imagery  

Microsoft Academic Search

We estimated phytoplankton primary productivity (PP) in the euphotic zone of the California Current System using chlorophyll concentration (Chl) from CZCS imagery. The area was divided into two regions, Southern California (SC) and Baja California (BC), with inshore and offshore subregions, and into two seasons, cool and warm. The Chl and PP values were in general higher and more variable

OA Barocio-Len; R Milln-Nez; E Santamara-del-ngel; A Gonzlez-Silvera

134

California Mediterranean Rangelands and Ecosystem Conservation Lynn Huntsinger, Professor, Environmental Science, Policy and Management, MC 3110, University  

E-print Network

, Environmental Science, Policy and Management, MC 3110, University of California, Berkeley , 94720. huntsinger "engineered" by livestock grazing, cultivation, fire suppression, and the introduction of exotic species

Kammen, Daniel M.

135

EFFECTS OF BIODIVERSITY ON ECOSYSTEM FUNCTIONING: A CONSENSUS OF CURRENT KNOWLEDGE  

Microsoft Academic Search

Humans are altering the composition of biological communities through a variety of activities that increase rates of species invasions and species extinctions, at all scales, from local to global. These changes in components of the Earth's biodiversity cause concern for ethical and aesthetic reasons, but they also have a strong potential to alter ecosystem properties and the goods and services

D. U. Hooper; F. S. Chapin; J. J. Ewel; A. Hector; P. Inchausti; S. Lavorel; J. H. Lawton; D. M. Lodge; M. Loreau; S. Naeem; B. Schmid; H. Setl; A. J. Symstad; J. Vandermeer; D. A. Wardle

2005-01-01

136

Climate change, reproductive performance and diet composition of marine birds in the southern California Current system, 19691997  

Microsoft Academic Search

We studied the effects of low-frequency climate change on the reproductive performance of 11 species of marine bird in the southern California Current system, 19691997. Reproductive performance of Brown Pelican (Pelecanus occidentalis) and Double-crested Cormorant (Phalacrocrax auritus) in southern California demonstrated an increase in the 1970s and early 1980s, attributable to recovery from organochlorine contamination (primarily DDE). Brandt's Cormorant (Phalacrocorax

William J. Sydeman; Michelle M. Hester; Julie A. Thayer; Franklin Gress; Paige Martin; Joelle Buffa

2001-01-01

137

The current state of quality of care measurement in the California Department of Corrections and Rehabilitation.  

PubMed

The quality of health care in prisons is lacking in many states. In particular, the California Department of Corrections and Rehabilitation (CDCR) is in the midst of an extreme legal remedy to address problems related to access to and quality of care; it now operates under the direction of a federally appointed receiver for medical care. To understand the current state of access and quality measurement and to assess strengths and weaknesses of current activities, the RAND Corporation conducted a series of interviews and site visits in the CDCR and related offices as well as document reviews (December 2008 to February 2009). Findings supported RAND's larger project goals to identify measures for use in a sustainable quality measurement system. PMID:21525115

Teleki, Stephanie S; Damberg, Cheryl L; Shaw, Rebecca; Hiatt, Liisa; Williams, Brie; Hill, Terry E; Asch, Steven M

2011-04-01

138

Observed and modeled tsunami current velocities in Humboldt Bay and Crescent City Harbor, northern California  

NASA Astrophysics Data System (ADS)

A pilot project was initiated in 2009 in Humboldt Bay, about 370 kilometers (km) north of San Francisco, California, to measure the currents produced by tsunamis. Northern California is susceptible to both near- and far-field tsunamis and has a historic record of damaging events. Crescent City Harbor, located approximately 100 km north of Humboldt Bay, suffered US 20 million in damages from strong currents produced by the 2006 Kuril Islands tsunami and an additional US 20 million from the 2011 Japan tsunami. In order to better evaluate these currents in northern California, we deployed a Nortek Aquadopp 600kHz 2D Acoustic Doppler Current Profiler (ADCP) with a one-minute sampling interval in Humboldt Bay, near the existing National Oceanic and Atmospheric Administration (NOAA) National Ocean Service (NOS) tide gauge station. The instrument recorded the tsunamis produced by the Mw 8.8 Chile earthquake on February 27, 2010 and the Mw 9.0 Japan earthquake on March 11, 2011. Currents from the 2010 tsunami persisted in Humboldt Bay for at least 30 hours with peak amplitudes of about 0.3 meters per second (m/s). The 2011 tsunami signal lasted for over 86 hours with peak amplitude of 0.95 m/s. Strongest currents corresponded to the maximum change in water level as recorded on the NOAA NOS tide gauge, and occurred 90 minutes after the initial wave arrival. No damage was observed in Humboldt Bay for either event. In Crescent City, currents for the first three and a half hours of the 2011 Japan tsunami were estimated using security camera video footage from the Harbor Master building across from the entrance to the small boat basin, approximately 70 meters away from the NOAA NOS tide gauge station. The largest amplitude tide gauge water-level oscillations and most of the damage occurred within this time window. The currents reached a velocity of approximately 4.5 m/s and six cycles exceeded 3 m/s during this period. Measured current velocities both in Humboldt Bay and in Crescent City were compared to calculated velocities from the Method of Splitting Tsunamis (MOST) numerical model. For Humboldt Bay, the 2010 model tsunami frequencies matched the actual values for the first two hours after the initial arrival however the amplitudes were underestimated by approximately 65%. MOST replicated the first four hours of the 2011 tsunami signal in Humboldt Bay quite well although the peak flood currents were underestimated by about 50%. MOST predicted attenuation of the signal after four hours but the actual signal persisted at a nearly constant level for more than 48 hours. In Crescent City, the model prediction of the 2011 frequency agreed quite well with the observed signal for the first two and a half hours after the initial arrival with a 50% underestimation of the peak amplitude. The results from this project demonstrate that ADCPs can effectively record tsunami currents for small to moderate events and can be used to calibrate and validate models (i.e. MOST) in order to better predict hazardous tsunami conditions and improve planned responses to protect lives and property, especially within harbors. An ADCP will be installed in Crescent City Harbor and four additional ADCPs are being deployed in Humboldt Bay during the fall of 2012.

Admire, A. R.; Dengler, L.; Crawford, G. B.; uslu, B. U.; Montoya, J.

2012-12-01

139

Using the Terrestrial Observation and Prediction System (TOPS) to Analyze Impacts of Climate Change on Ecosystems within Northern California Climate Regions  

NASA Astrophysics Data System (ADS)

The projected impacts of climate change on Northern California ecosystems using model outputs from the Terrestrial Observation and Prediction System (TOPS) for the period 1950-2099 based on 1km downscaled climate data from the Geophysical Fluid Dynamics Laboratory (GFDL) model are analyzed in this study. The impacts are analyzed for the Special Report Emissions Scenarios (SRES) A1B and A2, both maintaining present levels of urbanization constant and under projected urban expansion. The analysis is in support of the Climate Adaptation Science Investigation at NASA Ames Research Center. A statistical analysis is completed for time series of temperature, precipitation, gross primary productivity (GPP), evapotranspiration, soil runoff, and vapor pressure deficit. Trends produced from this analysis show that increases in maximum and minimum temperatures lead to declines in peak GPP, length of growing seasons, and overall declines in runoff within the watershed. For Northern California, GPP is projected under the A2 scenario to decrease by 18-25% by the 2090 decade as compared to the 2000 decade. These trends indicate a higher risk to crop production and other ecosystem services, as conditions would be less hospitable to vegetation growth. The increase in dried out vegetation would then lead to a higher risk of wildfire and mudslides in the mountainous regions.

Pitts, K.; Little, M.; Loewenstein, M.; Iraci, L. T.; Milesi, C.; Schmidt, C.; Skiles, J. W.

2011-12-01

140

Constraining the timing of turbidity current driven sediment transport down Monterey Canyon, offshore California  

NASA Astrophysics Data System (ADS)

Turbidity currents are responsible for transport of sand down the Monterey Submarine Canyon, offshore California, from the shoreline to Monterey Fan. However the timing of sediment transport events and their frequencies are not fully understood despite recent monitoring of canyon events and AMS 14C dating of foraminifera from hemipelagic sediments bracketing sand deposited during turbidity flows. Quartz optically stimulated luminescence (OSL) dating in sand sequences provides a complementary means of dating sand transport. OSL dates reflect the time interval since the sand grains were last exposed to sunlight. However, the technique has never been applied extensively to canyon sediments before. Here we report both quartz OSL ages of sand deposits and benthic foraminifera ages sampled from the axial channel within Monterey Submarine Canyon and Fan via ROV-collected vibracores. This allows a rare opportunity to directly test the frequency and timing of turbidity current events at different points in the canyon. We use both single-grain and small (~2 mm area) single aliquot regeneration OSL approaches on vibracore samples from various water depths to determine sand transport frequency. Within the upper canyon (<2,000 m water depths) the OSL data require sub-decadal to decadal transit times. Sand bearing fining upward sequences yielding middle Holocene to last few hundred year ages indicate turbidity currents occur at 150 to 250 year event frequencies within the fan channel out to 3,600 m water depth. We suggest that turbidity currents have been active during the current sea-level high stand and that the submarine fan has recorded turbidity currents over the entire Holocene. The increased age spread in single grain OSL dates with water depth provides evidence of sediment mixing and reworking during turbidity flows. Apparently, sand is stored within the canyon for various amounts of time while it is in route to its current location on the fan.

McGann, M.; Stevens, T.; Paull, C. K.; Ussler, W.; Buylaert, J.

2013-12-01

141

Ecosystem scenarios shape fishermen spatial behavior. The case of the Peruvian anchovy fishery in the Northern Humboldt Current System  

NASA Astrophysics Data System (ADS)

A major goal in marine ecology is the understanding of the interactions between the dynamics of the different ecosystem components, from physics to top predators. While fishermen are among the main top predators at sea, almost none of the existing studies on ecology from physics to top predators contemplate fishermen as part of the system. The present work focuses on the coastal processes in the Northern Humboldt Current System, which encompasses both an intense climatic variability and the largest monospecific fishery of the world. From concomitant satellite, acoustic survey and Vessel Monitoring System data (?90,000 fishing trips) for a ten-year period (2000-2009), we quantify the associations between the dynamics of the spatial behavior of fishermen, environmental conditions and anchovy (Engraulis ringens) biomass and spatial distribution. Using multivariate statistical analyses we show that environmental and anchovy conditions do significantly shape fishermen spatial behavior and present evidences that environmental fluctuations smoothed out along trophic levels. We propose a retrospective analysis of the study period in the light of the ecosystem scenarios evidenced and we finally discuss the potential use of fishermen spatial behavior as ecosystem indicator.

Joo, Rocio; Bertrand, Arnaud; Bouchon, Marilu; Chaigneau, Alexis; Demarcq, Herv; Tam, Jorge; Simier, Monique; Gutirrez, Dimitri; Gutirrez, Mariano; Segura, Marceliano; Fablet, Ronan; Bertrand, Sophie

2014-11-01

142

An evaluation of the latitudinal gradient of chlorophyll in the California Current  

NASA Astrophysics Data System (ADS)

Tracking of spatial and temporal trends in phytoplankton abundance and distribution is an important step toward understanding large-scale macroecological processes in the ocean. Measurements of ocean radiance from satellite-borne sensors, such as SeaWiFS and MODIS, can be used to estimate surface chlorophyll concentration, which is a good indicator of phytoplankton biomass. The primary goal of this study was to evaluate the latitudinal gradient in chlorophyll concentration within the California Current first reported by Ware and Thomson (2005). They found that average chlorophyll concentration tended to increase steadily from 32-48N latitude. This concentration gradient was reevaluated using a longer dataset and an algorithm refined for the region. Radiance data from the MODIS-Aqua instrument were obtained for every year from 2002 through 2013. Data included annual averages of remote sensing radiance as well as monthly averages for February, April, and August. These months were chosen to represent each of the three oceanographic seasons present in the California Current. Estimates of chlorophyll concentration were derived from these data using the CALFIT algorithm developed by Kahru et al. (2012). The resulting maps of chlorophyll concentration were processed in MATLAB and linear regressions were performed using SYSTAT 13 software. A statistically significant (p < 0.05) latitudinal trend in chlorophyll was observed in the annual averaged data as well as in the averaged seasonal data from February and August. No significant trend was observed in the averaged April data. Chlorophyll concentration was positively correlated with latitude in every instance, except in April 2003 and April 2005, where a negative correlation was observed. The positive latitudinal trend was strongest during August and weakest during April. Strong peaks in chlorophyll were observed near San Francisco Bay and the mouth of the Columbia River, suggesting that river-borne nutrient input may be the dominant factor responsible for the existence of this chlorophyll gradient.

Dietrich, W.; Broughton, J.; Kudela, R. M.

2013-12-01

143

Differences in dynamic response of California Current salmon species to changes in ocean conditions  

NASA Astrophysics Data System (ADS)

While changes in the northeast Pacific Ocean in the mid-1970s apparently caused changes in salmon population growth in the Gulf of Alaska and the California Current, the responses of California Current salmon species, coho salmon ( Oncorhynchus kisutch) and chinook salmon ( O. tshawytscha) differed. Coho salmon catches declined dramatically along the coasts of California, Oregon and Washington, while chinook salmon catches did not. This provides an opportunity for comparative analysis, a rarity in the study of long-term changes in the ocean. Here we test one possible explanation for that difference, that chinook salmon populations are inherently more persistent because chinook salmon populations spawn over a range of ages, while coho salmon spawn predominantly at age 3 yr. We extended a previous theoretical approach that had been used to assess the long-term response of salmon populations with various spawning age structures to different means and variances in environmental variability. New results indicate that populations with environmental variability at the age of return to freshwater have the same characteristic identified earlier for populations with variability in the age of entry: populations spawning at multiple ages are more persistent, but that increased persistence is gained in the first few percent of departure from all spawning at a single age. Thus, in both cases the results are too sensitive to values of uncertain parameters to depend on as an explanation of the differences in response. We also approached this question by subjecting model populations with coho and chinook salmon spawning age structures to an empirical estimate of actual marine survival of coho salmon over the years 1970-2002, asking the question, if chinook salmon had been subjected to the same ocean survivals would they have experienced the same decline. The differences in spawning age structure made little difference in population responses. The dominant factor influencing the response of these species to a decline in ocean survival was the behavior of the freshwater spawner/smolt relationship at low abundance, a factor that has recently been intensively studied for coho salmon, but is poorly known for chinook salmon. These results suggest that the GLOBEC NEP should focus attention on the ocean phase of salmon life, to explain the observed difference in population response to changes in physical conditions.

Botsford, Louis W.; Lawrence, Cathryn A.; Forrest Hill, M.

2005-01-01

144

Rapid formation of hyperpycnal sediment gravity currents offshore of a semi-arid California river  

USGS Publications Warehouse

Observations of sediment dispersal from the Santa Clara River of southern California during two moderately sized river discharge events suggest that river sediment rapidly formed a negatively buoyant (hyperpycnal) bottom plume along the seabed within hours of peak discharge. An array of acoustic and optical sensors were placed at three stations 1 km from the Santa Clara River mouth in 10-m water depth during January-February 2004. These combined observations suggest that fluid mud concentrations of suspended sediment (>10 g/l) and across-shore gravity currents (???5 cm/s) were observed in the lower 20-40 cm of the water column 4-6 h after discharge events. Gravity currents were wave dominated, rather than auto-suspending, and appeared to consist of silt-to-clay sized sediment from the river. Sediment mass balances suggest that 25-50% of the discharged river sediment was transported by these hyperpycnal currents. Sediment settling purely by flocs (???1 mm/s) cannot explain the formation of the observed hyperpycnal plumes, therefore we suggest that some enhanced sediment settling from mixing, convective instabilities, or diverging plumes occurred that would explain the formation of the gravity currents. These combined results provide field evidence that high suspended-sediment concentrations from rivers (>1 g/l) may rapidly form hyperpycnal sediment gravity currents immediately offshore of river mouths, and these pathways can explain a significant portion of the river-margin sediment budget. The fate of this sediment will be strongly influenced by bathymetry, whereas the fate of the remaining sediment will be much more influenced by ocean currents.

Warrick, J.A.; Xu, J.; Noble, M.A.; Lee, H.J.

2008-01-01

145

Air-sea exchange of CO2 at a Northern California coastal site along the California Current upwelling system  

NASA Astrophysics Data System (ADS)

Uncertainty in the air-sea CO2 exchange (CO2 flux) in coastal upwelling zones is attributed to high temporal variability, which is caused by changes in ocean currents. Upwelling transports heterotrophic, CO2 enriched water to the surface and releases CO2 to the atmosphere, whereas the presence of nutrient-rich water at the surface supports high primary production and atmospheric CO2 uptake. To quantify the effects of upwelling on CO2 fluxes, we measured CO2 flux at a coastal upwelling site off of Bodega Bay, California, during the summer of 2007 and the fall of 2008 using the eddy covariance technique and the bulk method with pCO2 measurements from November 2010 to July 2011. Variations in sea surface temperatures (SST) and alongshore wind speeds suggest that the measurement period in 2007 coincided with a typical early-summer upwelling period and the measurement period in 2008 was during a typical fall relaxation period. A strong source of CO2 (~1.5 7 SD (standard deviation) g C m-2 day-1) from the ocean to the atmosphere during the upwelling period was concurrent with high salinity, low SST, and low chlorophyll density. In contrast, a weak source of CO2 flux (~0.2 3 SD g C m-2 day-1) was observed with low salinity, high SST and high chlorophyll density during the relaxation period. Similarly, the sink and source balance of CO2flux was highly related to salinity and SST during the pCO2 measurement periods; high salinity and low SST corresponded to high pCO2, and vice versa. We estimated that the coastal area off Bodega Bay was likely a source of CO2 to the atmosphere based on the following conclusions: (1) the overall CO2 flux estimated from both eddy covariance and pCO2 measurements showed a source of CO2; (2) although the relaxation period during the 2008 measurements were favorable to CO2 uptake, CO2 flux during this period was still a slight source, (3) salinity and SST were found to be good predictors of the CO2 flux for both eddy covariance and pCO2 measurements, and historical data of daily averaged SST and salinity between 1988 to 2011 show that 99% of the data falls within the range of our observation in May-June 2007, August-September 2008 and November 2010-July 2011 indicating that our data set was representative of the annual variations in the sea state. Based on the developed relationship between pCO2 and SST and salinity, the average annual CO2 flux between 1988 and 2011 was estimated to be ~35 mol C m-2 yr-1. The peak monthly CO2 flux of ~7 mol C m-2 month-1 accounted for about 30% of the dissolved inorganic carbon in the surface mixed-layer.

Ikawa, H.; Faloona, I.; Kochendorfer, J.; Paw U, K. T.; Oechel, W. C.

2012-12-01

146

Wind-driven variability in sea surface temperature front distribution in the California Current System  

NASA Astrophysics Data System (ADS)

satellite-derived observations from 2002 to 2009 are used to quantify the relation between sea surface temperature (SST) fronts and ocean winds in the California Current System (CCS). An edge-detection algorithm is applied to SST observations to generate monthly maps of frontal probabilities. Empirical orthogonal decompositions reveal that the seasonal evolution of fronts in the CCS is strongly related to the seasonal evolution of coastal alongshore wind stress. The seasonal development of SST fronts is remarkably different to the north and to the south of Cape Mendocino, however. While fronts to the north of the cape extend for hundreds of kilometers from the coast peaking during summer and fall, when upwelling winds are stronger off northern California and Oregon, the region to the south of Cape Mendocino is characterized by high frontal activity during spring in a much narrower band close to the coast. Throughout the region, anomalies in the intensity of upwelling-favorable wind stress are followed by anomalies in frontal activity. The width and speed of the widening of the region of high frontal activity are also related to coastal alongshore wind stress. Interannual variability in the timing of the widening of the region of high frontal activity in the lee of Cape Blanco compared to the timing of the spring transition to upwelling-favorable winds may be related to the wind stress curl distribution in the lee of the cape. Stronger upwelling-favorable wind stress curl anomalies lead to early widening of the region of high frontal activity.

Castelao, Renato M.; Wang, Yuntao

2014-03-01

147

Springtime distributions of migratory marine birds in the southern California Current: Oceanic eddy associations and coastal habitat hotspots over 17 years  

Microsoft Academic Search

We used a 17-year time series of shipboard observations to address the hypothesis that marine birds associate with persistent hydrographic features in the southern California Current System (CCS). Overall, approximately 27,000 km of ocean habitat were surveyed, averaging 1600 km per cruise. We identified mesoscale features (eddy centers and the core of the California Current), based on dynamic height anomalies,

P. P. W. Yen; W. J. Sydeman; S. J. Bograd; K. D. Hyrenbach

2006-01-01

148

Recovery strategies for the California clapper rail ( Rallus longirostris obsoletus) in the heavily-urbanized San Francisco estuarine ecosystem  

Microsoft Academic Search

The California clapper rail (Rallus longirostris obsoletus), a Federal- and State-listed endangered marsh bird, has a geographic range restricted to one of the most heavily-urbanized estuaries in the world. The rail population has long been in a state of decline, although the exact contribution of each of the many contributing causes remains unclear. The rail is one of the key

Theodore C. Foin; E. Jacqueline Garcia; Robert E. Gill; Steven D. Culberson; Joshua N. Collins

1997-01-01

149

Dogs, humans and island ecosystems: the distribution, antiquity and ecology of domestic dogs (Canis familiaris) on California's Channel Islands, USA  

Microsoft Academic Search

Archaeologists have made significant contributions to our understanding of ancient island environments, including the timing and implications of the introduction of non-native animals (pigs, chickens, rats, etc.) by humans. Here, we focus on the historical ecology and biogeography of domestic dogs (Canis familiaris) on California's Channel Islands during the Holocene. Dogs are the only animal known unequivocally to have been

Torben C. Rick; Phillip L. Walker; Lauren M. Willis; Anna C. Noah; Jon M. Erlandson; Ren L. Vellanoweth; Todd J. Braje; Douglas J. Kennett

2008-01-01

150

The Effects of Sea Level Rise on Ecosystem Productivity, Microbial Populations, and Soil pH along the California Coast  

Microsoft Academic Search

With rising sea levels due to global climate change on the horizon, I constructed multiple soil systems modeling various levels of potential soil salinity resulting from flooding along the coast of California. Since a fair amount of the coast is made up of exclusive residential property, agricultural land, and nature preserves, the potential for financial and biological damages due to

Alexandra Forman

2010-01-01

151

Effect of soil temperature and soil water content on fine root turnover rate in a California mixed conifer ecosystem  

Microsoft Academic Search

Measurement of fine root production and turnover rate, the reciprocal of mean life span of a root population, is crucial to the understanding of the carbon cycle of an ecosystem as fine roots account for up to 30% of global terrestrial net primary production. Our goal was to characterize fine root production, mortality, standing crop, and turnover rate in a

Kuni Kitajima; Kurt E. Anderson; Michael F. Allen

2010-01-01

152

Coupled 4D-variational physical and biological data assimilation in the California Current System  

NASA Astrophysics Data System (ADS)

Coupled physical and biological data assimilation is performed within the California Current System using a 3-dimensional coupled physical-biological model using the four-dimensional variational (4DVar) method and assuming Gaussian and lognormal error distributions for physical and biological variables, respectively. Errors are assumed to be independent, yet variables are coupled by assimilation through adjoint model dynamics. Using a nutrient-phytoplankton-zooplankton-detritus (NPZD) model coupled to an ocean circulation model (the Regional Ocean Modeling System), the coupled data assimilation procedure is evaluated in a twin experiment setting and compared to two related experiments, assimilating physical data only and biological data only. Independent assimilation of physical (biological) data reduces the root-mean-squared error of physical (biological) state variables by more than 56% (46%) on average. However, the improvement in biological (physical) state variables is less than 7% (12%). In contrast, coupled data assimilation shows improvement in both physical and biological components by 57% and 52%, respectively, illustrating the superior performance of the coupled assimilation approach.

Song, H.; Edwards, C. A.; Moore, A. M.; Fiechter, J.

2012-12-01

153

Changes in production and respiration during a spring phytoplankton bloom in San Francisco Bay, California, USA: Implications for net ecosystem metabolism  

USGS Publications Warehouse

We present results of an intensive sampling program designed to measure weekly changes in ecosystem respiration (oxygen consumption in the water column and sediments) around the 1996 spring bloom in South San Francisco Bay, California, USA. Measurements were made at a shallow site (2 m, where mean photic depth was 60% of the water column height) and a deep site (15 m, mean photic depth was only 20% of the water column). We also estimated phytoplankton primary production weekly at both sites to develop estimates of net oxygen flux as the sum of pelagic production (PP), pelagic respiration (PR) and benthic respiration (BR). Over the 14 wk period from February 5 to May 14, PP ranged from 2 to 210, PR from 9 to 289, and BR from 0.1 to 48 mmol O2 m-2 d-1, illustrating large variability of estuarine oxygen fluxes at the weekly time scale. Pelagic production exceeded total respiration at the shallow site, but not at the deep site, demonstrating that the shallow domains are net autotrophic but the deep domains are net heterotrophic, even during the period of the spring bloom. If we take into account the potential primary production by benthic microalgae, the estuary as a whole is net autotrophic during spring, net heterotrophic during the nonbloom seasons, and has a balanced net metabolism over a full annual period. The seasonal shift from net autotrophy to heterotrophy during the transition from spring to summer was accompanied by a large shift from dominance by pelagic respiration to dominance by benthic respiration. This suggests that changes in net ecosystem metabolism can reflect changes in the pathways of energy flow in shallow coastal ecosystems.

Caffrey, J. M.; Cloern, J. E.; Grenz, C.

1998-01-01

154

Biogeography and phenology of satellite-measured phytoplankton seasonality in the California current  

NASA Astrophysics Data System (ADS)

Thirteen years (1998-2010) of satellite-measured chlorophyll a are used to establish spatial patterns in climatological phytoplankton biomass seasonality across the California Current System (CCS) and its interannual variability. Multivariate clustering based on the shape of the local climatological seasonal cycle divides the study area into four groups: two with spring-summer maxima representing the northern and southern coastal upwelling zones, one with a summer minimum offshore in mid-latitudes and a fourth with very weak seasonality in between. Multivariate clustering on the seasonal cycles from all 13 years produces the same four seasonal cycle types and provides a view of the interannual variability in seasonal biogeography. Over the study period these seasonal cycles generally appear in similar locations as the climatological clusters. However, considerable interannual variability in the geography of the seasonal cycles is evident across the CCS, the most spatially extensive of which are associated with the 1997-1999 El Nio-Southern Oscillation (ENSO) signal and the 2005 delayed spring transition off the Oregon and northern and central California coasts. We quantify linear trends over the study period in the seasonal timing of the two seasonal cycles that represent the biologically productive coastal upwelling zones using four different metrics of phenology. In the northern upwelling region, the date of the spring maximum is delaying (1.34 days yr-1) and the central tendency of the summer elevated chlorophyll period is advancing (0.63 days yr-1). In the southern coastal upwelling region, both the initiation and cessation of the spring maximum are delaying (1.78 days yr-1 and 2.44 days yr-1, respectively) and the peak is increasing in duration over the study period. Connections between observed interannual shifts in phytoplankton seasonality and physical forcing, expressed as either basin-scale climate signals or local forcing, show phytoplankton seasonality in the CCS to be influenced by changes in the seasonality of the wind mixing power offshore, coastal upwelling in the near-shore regions and basin-scale signals such as ENSO across the study area.

Foukal, Nicholas P.; Thomas, Andrew C.

2014-10-01

155

Current status and historical trends of organochlorine pesticides in the ecosystem of Deep Bay, South China  

Microsoft Academic Search

To characterize the current status and historical trends in organochlorine pesticides (OCPs) contamination in Deep Bay, an important water body between Hong Kong and mainland China with a Ramsar mangrove wetland (Maipo), samples from seawater, suspended particulate matter (SPM), surface sediment, sediment core and fish were collected to determine the OCPs concentrations. Sediment core dating was accomplished using the 210Pb

Yao-Wen Qiu; Gan Zhang; Ling-Li Guo; Hai-Rong Cheng; Wen-Xiong Wang; Xiang-Dong Li; Onyx W. H. Wai

2009-01-01

156

The invasive bullfrog Lithobates catesbeianus in oases of Baja California Sur, Mexico: potential effects in a fragile ecosystem  

Microsoft Academic Search

The American bullfrog (Lithobates catesbeianus), considered as one of the worlds worst invasive species because of its negative effects on native fauna, has been introduced\\u000a into over 40 countries in four continents. The invasion status in Mexico is poorly known. The first known record for this\\u000a species in the Peninsula of Baja California, northwestern Mexico is an individual collected 35years

Vctor H. Luja; Ricardo Rodrguez-Estrella

2010-01-01

157

Professional Statement Currently I am an Associate Professor of Geography at the University of California,  

E-print Network

), the University of California Center for U.S.-Mexican Studies (USMEX) and the Center for Comparative Immigration, and BALANCE), and the conceptual framework for Emerging Trends in Environment and Economic Growth in Latin

Lopez-Carr, David

158

Ecosystem Services and Environmental Benefits  

E-print Network

Ecosystem Services and Environmental Benefits of the UC San Diego Campus Forest 10 February 2009 #12;2 #12;3 Ecosystem Services and Environmental Benefits of the UC San Diego Campus Forest 10 of the University of California, San Diego (UCSD), is a rich and varied ecosystem stretching from the Pacific Ocean

Tsien, Roger Y.

159

Salton Sea ecosystem monitoring and assessment plan  

USGS Publications Warehouse

The Salton Sea, Californias largest lake, provides essential habitat for several fish and wildlife species and is an important cultural and recreational resource. It has no outlet, and dissolved salts contained in the inflows concentrate in the Salton Sea through evaporation. The salinity of the Salton Sea, which is currently nearly one and a half times the salinity of ocean water, has been increasing as a result of evaporative processes and low freshwater inputs. Further reductions in inflows from water conservation, recycling, and transfers will lower the level of the Salton Sea and accelerate the rate of salinity increases, reduce the suitability of fish and wildlife habitat, and affect air quality by exposing lakebed playa that could generate dust. Legislation enacted in 2003 to implement the Quantification Settlement Agreement (QSA) stated the Legislatures intent for the State of California to undertake the restoration of the Salton Sea ecosystem. As required by the legislation, the California Resources Agency (now California Natural Resources Agency) produced the Salton Sea Ecosystem Restoration Study and final Programmatic Environmental Impact Report (PEIR; California Resources Agency, 2007) with the stated purpose to develop a preferred alternative by exploring alternative ways to restore important ecological functions of the Salton Sea that have existed for about 100 years. A decision regarding a preferred alternative currently resides with the California State Legislature (Legislature), which has yet to take action. As part of efforts to identify an ecosystem restoration program for the Salton Sea, and in anticipation of direction from the Legislature, the California Department of Water Resources (DWR), California Department of Fish and Wildlife (CDFW), U.S. Bureau of Reclamation (Reclamation), and U.S. Geological Survey (USGS) established a team to develop a monitoring and assessment plan (MAP). This plan is the product of that effort. The goal of the MAP is to provide a guide for data collection, analysis, management, and reporting to inform management actions for the Salton Sea ecosystem. Monitoring activities are directed at species and habitats that could be affected by or drive future restoration activities. The MAP is not intended to be a prescriptive document. Rather, it is envisioned to be a flexible, program-level guide that articulates high-level goals and objectives, and establishes broad sideboards within which future project-level investigations and studies will be evaluated and authorized. As such, the MAP, by design, does not, for example, include detailed protocols describing how investigations will be implemented. It is anticipated that detailed study proposals will be prepared as part of an implementation plan that will include such things as specific sampling objectives, sampling schemes, and statistical and spatial limits.

Case(compiler), H. L., III; Boles, Jerry; Delgado, Arturo; Nguyen, Thang; Osugi, Doug; Barnum, Douglas A.; Decker, Drew; Steinberg, Steven; Steinberg, Sheila; Keene, Charles; White, Kristina; Lupo, Tom; Gen, Sheldon; Baerenklau, Ken A.

2013-01-01

160

Dissolved Organic Carbon and Nitrogen Leaching From Soil Formed in Grass, Oak and Pine Ecosystems of California  

NASA Astrophysics Data System (ADS)

Dissolved organic matter (DOM) leaching from decomposing detritus accumulated above mineral soils is an important carbon (C) and nitrogen (N) flux that influences biogeochemical processes, C sequestration and the health of individual ecosystems. This study compared the retention and transformation of DOM leached through soils formed under three contrasting vegetation types. In a laboratory study, columns of surface soil (10 cm diameter, 10 cm height) from either a grass, oak or pine site were leached with DOM derived from either grass, oak or pine litter. In the field, the laboratory study was replicated by burying columns of soil from the grass, oak and pine sites under the organic horizon at each sites. Leachates from in-situ field columns were collected biweekly beginning in January 2005. Samples were analyzed for volume, pH, total N, NO3-, NH4+, DON and DOC. In the laboratory leaching studies soils retained DOC derived from its native ecosystem to a greater extent. These results suggest that the microbial community from each ecosystem is adapted to consume the native DOC. No clear trends were found with DOC in the field study. Leachates from the field columns did show significantly lower levels of DON from pine soil columns at all sampling dates and sites. Similar results were found in the laboratory study with pine soil decreasing initial total N inputs from 32.9 to 3.6 mg kg-1. While all three sites contain kaolinite, vermiculite and chlorite, soil from the pine site also has high levels of iron oxides and gibbsite. The greater iron content likely contributes to higher DON retention since these minerals are know to have high affinities for the retention of DOM. The results from the field and laboratory experiments show that both soil minerals and the soil microbial communities play an important role in DOM retention in the subsoil.

Pittiglio, S. L.; Zasoski, R. J.

2005-12-01

161

Epipelagic and mesopelagic fishes in the southern California Current System: Ecological interactions and oceanographic influences on their abundance  

NASA Astrophysics Data System (ADS)

We use zooplankton and ichthyoplankton data from the ~ 60-year CalCOFI time series to examine relationships of mesopelagic (i.e. midwater) fishes in the California Current System with midwater predators, potential competitors (epipelagic planktivorous fishes) and zooplankton prey, within the context of local and basin-scale oceanography. Equilibrium-based near-steady state models and the wasp-waist paradigm for eastern boundary currents predict tightly-coupled trophic interactions, with negative correlations between the abundance of planktivorous competitors and between dominant planktivores and their prey. Testing these hypotheses with the CalCOFI time series, we found them to be generally invalid. Potential competitors within the mesopelagic community (planktivorous vertical migrators (VMs) and non-migrators (NMs)) were highly positively correlated, as were these groups with the mesopelagic piscivores (e.g. dragonfishes) that prey on them. In addition, the abundance of VMs was mostly positively correlated with that of epipelagic planktivores, such as anchovy, mackerels and hake. The VMs and epipelagic planktivores were negatively correlated with key potential planktonic prey groups, indicating a lack of bottom-up forcing. However, neither do these negative correlations appear to signify top-down forcing, since they seem to be mediated through correlations with key environmental drivers, such as the Pacific Decadal Oscillation (PDO), sea surface temperature, and the relative strength of the California Current. We suggest that the web of correlations linking key meso- and epipelagic planktivores, their predators and prey is mediated through common links with basin-scale oceanographic drivers, such as the PDO and ENSO cycles. Thus, the abundance of mesopelagic fishes in the California Current is closely tied to variation in the oxygen minimum zone, whose dynamics have been linked to the PDO. The PDO and other drivers are also linked to the transport of the California Current System, which influences the abundance of many dominant taxa off southern California that have broad biogeographic distributions linked to water masses that extend to the north (Transition Zone/sub-Arctic faunas) or the south (tropical/subtropical faunas).

Koslow, J. Anthony; Davison, Peter; Lara-Lopez, Ana; Ohman, Mark D.

2014-10-01

162

Wildfire and abrupt ecosystem disruption on California's Northern Channel Islands at the llerd-Younger Dryas boundary (13.0-12.9 ka)  

NASA Astrophysics Data System (ADS)

Sedimentary records from California's Northern Channel Islands and the adjacent Santa Barbara Basin (SBB) indicate intense regional biomass burning (wildfire) at the llerd-Younger Dryas boundary (13.0-12.9 ka) (All age ranges in this paper are expressed in thousands of calendar years before present [ka]. Radiocarbon ages will be identified and clearly marked " 14C years".). Multiproxy records in SBB Ocean Drilling Project (ODP) Site 893 indicate that these wildfires coincided with the onset of regional cooling and an abrupt vegetational shift from closed montane forest to more open habitats. Abrupt ecosystem disruption is evident on the Northern Channel Islands at the llerd-Younger Dryas boundary with the onset of biomass burning and resulting mass sediment wasting of the landscape. These wildfires coincide with the extinction of Mammuthus exilis [pygmy mammoth]. The earliest evidence for human presence on these islands at 13.1-12.9 ka (11,000-10,900 14C years) is followed by an apparent 600-800 year gap in the archaeological record, which is followed by indications of a larger-scale colonization after 12.2 ka. Although a number of processes could have contributed to a post 18 ka decline in M. exilis populations (e.g., reduction of habitat due to sea-level rise and human exploitation of limited insular populations), we argue that the ultimate demise of M. exilis was more likely a result of continental scale ecosystem disruption that registered across North America at the onset of the Younger Dryas cooling episode, contemporaneous with the extinction of other megafaunal taxa. Evidence for ecosystem disruption at 13-12.9 ka on these offshore islands is consistent with the Younger Dryas boundary cosmic impact hypothesis [Firestone, R.B., West, A., Kennett, J.P., Becker, L., Bunch, T.E., Revay, Z.S., Schultz, P.H., Belgya, T., Kennett, D.J., Erlandson, J.M., Dickenson, O.J., Goodyear, A.A., Harris, R.S., Howard, G.A., Kloosterman, J.B., Lechler, P., Mayewski, P.A., Montgomery, J., Poreda, R., Darrah, T., Que Hee, S.S., Smith, A.R., Stich, A., Topping, W., Wittke, J.H. Wolbach, W.S., 2007. Evidence for an extraterrestrial impact 12,900 years ago that contributed to the megafaunal extinctions and Younger Dryas cooling. Proceedings of the National Academy of Sciences 104, 16016-16021.].

Kennett, D. J.; Kennett, J. P.; West, G. J.; Erlandson, J. M.; Johnson, J. R.; Hendy, I. L.; West, A.; Culleton, B. J.; Jones, T. L.; Stafford, Thomas W., Jr.

2008-12-01

163

Air-sea exchange of CO2 at a Northern California coastal site along the California Current upwelling system  

NASA Astrophysics Data System (ADS)

It is not well understood whether coastal upwelling is a net CO2 source to the atmosphere or a net CO2 sink to the ocean due to high temporal variability of air-sea CO2 exchange (CO2 flux) in coastal upwelling zones. Upwelling transports heterotrophic, CO2 enriched water to the surface and releases CO2 to the atmosphere, whereas the presence of nutrient-rich water at the surface supports high primary production and atmospheric CO2 uptake. To quantify the effects of upwelling on CO2 flux, we measured CO2 flux at a coastal upwelling site off of Bodega Bay, California, with the eddy covariance technique during the summer of 2007 and the fall of 2008, and the bulk method with partial pressure of CO2 of surface water (pCO2) data from November 2010 to July 2011. Variations in sea surface temperatures (SST) and alongshore wind velocity suggest that the measurement period in 2007 coincided with a typical early summer upwelling period and the measurement period in 2008 was during a typical fall relaxation period. A strong source of CO2 (~ 1.5 7 SD (standard deviation) g C m-2 day-1) from the ocean to the atmosphere during the upwelling period was concurrent with high salinity, low SST, and low chlorophyll density. In contrast, a weak source of CO2 flux (~ 0.2 3 SD g C m-2 day-1) was observed with low salinity, high SST and high chlorophyll density during the relaxation period. Similarly, the sink and source balance of CO2 flux was highly related to salinity and SST during the pCO2 measurement periods; high salinity and low SST corresponded to high pCO2, and vice versa. We estimated that the coastal area off Bodega Bay was likely an overall source of CO2 to the atmosphere based on the following conclusions: (1) the overall CO2 flux estimated from both eddy covariance and pCO2 measurements showed a source of CO2; (2) although the relaxation period during the 2008 measurements were favorable to CO2 uptake, CO2 flux during this period was still a slight source; (3) salinity and SST were found to be good predictors of the CO2 flux for both eddy covariance and pCO2 measurements, and 99% of the historical SST and salinity data available between 1988 and 2011 fell within the range of our observations in May-June 2007, August-September 2008 and November 2010-July~2011, which indicates that our data set was representative of the annual variations in the sea state. Based on the developed relationship between pCO2, SST and salinity, the study area between 1988 and 2011 was estimated to be an annual source of CO2 of ~ 35 mol C m-2 yr-1. The peak monthly CO2 flux of ~ 7 mol C m-2 month-1 accounted for almost 30% of the dissolved inorganic carbon in the surface mixed layer.

Ikawa, H.; Faloona, I.; Kochendorfer, J.; Paw U, K. T.; Oechel, W. C.

2013-07-01

164

Rapid formation of hyperpycnal sediment gravity currents offshore of a semi-arid California river  

Microsoft Academic Search

Observations of sediment dispersal from the Santa Clara River of southern California during two moderately sized river discharge events suggest that river sediment rapidly formed a negatively buoyant (hyperpycnal) bottom plume along the seabed within hours of peak discharge. An array of acoustic and optical sensors were placed at three stations 1km from the Santa Clara River mouth in 10-m

Jonathan A. Warrick; Jingping Xu; Marlene A. Noble; Homa J. Lee

2008-01-01

165

Energy from California agriculture and forest resources: current and future potential and constraints  

Microsoft Academic Search

More than 0.3 Quad of energy in the form of liquid, solid, and gaseous fuels can be produced from California forests and farms without altering significantly the supply of food, feed or fiber. The costs of biomass to fuels via direct combustion and gasification conversion systems is now lower than the petroleum or natural gas-derived fuels that they would replace.

Sachs

1981-01-01

166

Pleistocene water cycle and eastern boundary current processes along the California continental margin  

Microsoft Academic Search

Coastal marine sediments contain mixtures of terrestrial and marine paleoclimate proxies that record how the coastal water cycle has behaved over long time frames. We explore a 600 kyr marine record from ODP Site 1018, located due west of Santa Cruz, California, to identify coastal wet and dry periods and to associate them with oceanographic processes. Wet periods in central

Mitchell Lyle; Linda Heusser; Christina Ravelo; Dyke Andreasen; Annette Olivarez Lyle; Noah Diffenbaugh

2010-01-01

167

VERTICAL DISTRIBUTION AND DIEL MIGRATION OF EUPHAUSIIDS IN THE CENTRAL REGION OF THE CALIFORNIA CURRENT  

E-print Network

VERTICAL DISTRIBUTION AND DIEL MIGRATION OF EUPHAUSIIDS IN THE CENTRAL REGION OF THE CALIFORNIA. Zooplankton assemblages in the nearshore regions differed from those farther offshore in having a larger euphausiid populations, particularly Euphausia pacifica, tended to be more pronounced in offshore waters

168

Distribution of cetaceans and sea-surface chlorophyll concentrations in the California Current  

Microsoft Academic Search

A census of marine mammals was conducted off the coast of California (USA) in 19791980. The distribution of seasurface chlorophyll was determined at the same time by onboard fluorometry and by remote sensing using the Coastal Zone Color Scanner on the Nimbus-7 satellite. Comparisons of species and chlorophyll distributions indicate that marine mammals are not randomly distributed with respect to

R. C. Smith; P. Dustan; D. Au; K. S. Baker; E. A. Dunlap

1986-01-01

169

Springtime distributions of migratory marine birds in the southern California Current: Oceanic eddy associations and coastal habitat hotspots over 17 years  

Microsoft Academic Search

We used a 17-year time series of shipboard observations to address the hypothesis that marine birds associate with persistent hydrographic features in the southern California Current System (CCS). Overall, approximately 27,000km of ocean habitat were surveyed, averaging 1600km per cruise. We identified mesoscale features (eddy centers and the core of the California Current), based on dynamic height anomalies, and considered

P. P. W. Yen; W. J. Sydeman; S. J. Bograd; K. D. Hyrenbach

2006-01-01

170

Altimeter-derived variability of surface velocities in the California Current System: 1. Evaluation of TOPEX altimeter velocity resolution  

NASA Astrophysics Data System (ADS)

In this paper, we evaluate the temporal and horizontal resolution of geostrophic surface velocities calculated from TOPEX satellite altimeter heights. Moored velocities (from vector-averaging current meters and an acoustic Doppler current profiler) at depths below the Ekman layer are used to estimate the temporal evolution and accuracy of altimeter geostrophic surface velocities at a point. Surface temperature gradients from satellite fields are used to determine the altimeter's horizontal resolution of features in the velocity field. The results indicate that the altimeter resolves horizontal scales of 50-80 km in the along-track direction. The rms differences between the altimeter and current meters are 7-8 cm s-1, much of which comes from small-scale variability in the oceanic currents. We estimate the error in the altimeter velocities to have an rms magnitude of 3-5 cm s-1 or less. Uncertainties in the eddy momentum fluxes at crossovers are more difficult to evaluate and may be affected by aliasing of fluctuations with frequencies higher than the altimeter's Nyquist frequency of 0.05 cycles d-1, as indicated by spectra from subsampled current meter data. The eddy statistics that are in best agreement are the velocity variances, eddy kinetic energy and the major axis of the variance ellipses. Spatial averaging of the current meter velocities produces greater agreement with all altimeter statistics and increases our confidence that the altimeter's momentum fluxes and the orientation of its variance ellipses (the statistics differing the most with single moorings) represent well the statistics of spatially averaged currents (scales of 50-100 km) in the ocean. Besides evaluating altimeter performance, the study reveals several properties of the circulation in the California Current System: (1) velocity components are not isotropic but are polarized, strongly so at some locations, (2) there are instances of strong and persistent small-scale variability in the velocity, and (3) the energetic region of the California Current is isolated and surrounded by a region of lower energy starting 500-700 km offshore. This suggests that the source of the high eddy energy within 500 km of the coast is the seasonal jet that develops each spring and moves offshore to the central region of the California Current, rather than a deep-ocean eddy field approaching the coast from farther offshore.

Strub, P. Ted; Chereskin, Teresa K.; Niiler, Pearn P.; James, Corinne; Levine, Murray D.

1997-01-01

171

Patterns of co-variability among California Current chinook salmon, coho salmon, Dungeness crab, and physical oceanographic conditions  

NASA Astrophysics Data System (ADS)

One of the primary motivations for the GLOBEC NEP program was the apparent inverse relationship between the increase in salmon populations in the Gulf of Alaska since the mid-1970s and concurrent declines in salmon populations in the California Current. The increase in abundance of some salmon species in the Gulf of Alaska can be plausibly explained based on mechanisms involving changes in physical structure, biological productivity, and salmon survival. To assess concurrent changes in salmon populations in the California Current and their possible physical and biological bases we examined temporal and spatial patterns of co-variability between biological variables and physical descriptors along the coasts of Washington, Oregon and California, from 1950 to 1990. The biological variables were catch records of coho salmon, chinook salmon and an ecologically related species, Dungeness crab. The physical variables were sea surface temperature, sea surface height (SSH) and the upwelling index (UWI). We found that while California Current coho salmon declined uniformly in the mid-1970s, consistent with the proposed inverse relationship, chinook salmon did not. All three species appear to be driven by the dominant mode of co-variability in the three physical variables, an indicator of warm/cool water conditions, but in different ways. In general, warm conditions have a negative effect on salmon at the age of ocean entry and spawning return, and Dungeness crab during the larval stage, while cool conditions have a positive effect. Differences in spatio-temporal variability between the two salmon species suggest they may respond to ocean conditions differently: coho salmon vary synchronously along the coast on annual time scales, while chinook salmon vary on slightly longer time scales in a specific spatial pattern. Dungeness crab vary on 10-year time scales, synchronously along the coast, except for the most southern areas (central California) where populations collapsed in the late 1950s. The dominant, warm/cool mode of physical co-variability, which drives these populations regionally, is related to basin-scale indices; it appeared to follow these indices in the 1950s and 1975-1990, but differs from them1960-1975, in ways that may be biologically important.

Botsford, L. W.; Lawrence, C. A.

172

Seasonality of photosynthetic parameters in a multi-specific and vertically complex forest ecosystem in the Sierra Nevada of California.  

PubMed

Understanding seasonal variations of photosynthetic parameters is critical for accurate modeling of carbon dioxide (CO2) uptake by ecosystems. Maximum carboxylation velocity (Vcmax), maximum rate of electron transport (Jmax), leaf respiration in the light (R(day)), light-saturated assimilation (Amax) and maximum quantum yield (Phi) were calculated from leaf gas exchange measurements made monthly throughout the year on leaves of three co-occuring evergreen species in a Pinus ponderosa Dougl. ex P. Laws. & C. Laws. forest with shrubs in the understory (Arctostaphylos manzanita Parry and Ceanothus cordulatus Kellogg.). The seasonality and relationships of the photosynthetic parameters with environmental and physiological variables differed among the species. The nitrogen-fixing species, C. cordulatus had the highest values of the parameters and the largest seasonal variation, whereas A. manzanita exhibited the lowest seasonality and weaker correlations with environmental variables. In general, variations in Vcmax were highly correlated with light, leaf mass per area and leaf nitrogen content on an area basis. Temporal scaling of the parameters with each other seemed possible for C. cordulatus and P. ponderosa. However, lags between these variables and Vcmax likely reflect the influences of other factors. The acclimation relationships found along vertical light gradients within canopies in other studies cannot be applied to seasonal variations. The Jmax to Vcmax ratio varied seasonally for P. ponderosa and A. manzanita, being lower at high light, high air temperature and low soil water content. PMID:16510388

Misson, Laurent; Tu, Kevin P; Boniello, Ralph A; Goldstein, Allen H

2006-06-01

173

Climate warming and the decline of zooplankton in the California current  

Microsoft Academic Search

Since 1951, the biomass of macrozooplankton in waters off southern California has decreased by 80 percent. During the same period, the surface layer warmed-by more than 1.5°C in some places-and the temperature differences across the thermocline increased. Increased stratification resulted in less lifting of the thermocline by wind-driven upwelling. A shallower source of upwelled waters provided less inorganic nutrient for

D. Roemmich; J. McGowan

1995-01-01

174

Climatic Warming and the Decline of Zooplankton in the California Current  

Microsoft Academic Search

Since 1951, the biomass of macrozooplankton in waters off southern California has decreased by 80 percent. During the same period, the surface layer warmed-by more than 1.5^circC in some places-and the temperature difference across the thermocline increased. Increased stratification resulted in less lifting of the thermocline by wind-driven upwelling. A shallower source of upwelled waters provided less inorganic nutrient for

Dean Roemmich; John McGowan

1995-01-01

175

Interannual variability in bottom-up processes in the upstream range of the California Current system: An isotopic approach  

NASA Astrophysics Data System (ADS)

The abundance and composition of zooplankton, fish and seabirds show dramatic interannual variability in temperate coastal regions. Understanding links between this variability and bottom-up processes is an important goal for biological oceanographers. Because zooplankton stable isotopes (?15N and ?13C) are potentially influenced by variability in phytoplankton nutrient utilization, primary production, and zooplankton trophic structure, they have the potential to elucidate links between bottom-up processes, food web structure, and abundance or species composition of higher trophic levels. Here we measure correlations between zooplankton stable isotopes and oceanographic variables in two time series from the west coast of Vancouver Island, upstream of the California Current upwelling system. We then relate interannual variability in zooplankton stable isotopes to interannual variability in zooplankton species composition. Zooplankton stable isotopes show striking patterns of seasonal, regional and interannual variability. A strong positive correlation between annual averages of zooplankton ?15N and sea-surface temperature is evident in both time series. Zooplankton ?15N is also negatively correlated with interannual anomalies of subarctic copepod biomass in both time series. We propose two different mechanisms to explain these correlations: variability in the strength and direction of horizontal advection, or local fluctuations nutrient availability. We conclude that they are most likely caused by local, temperature-driven fluctuations in nitrate concentrations and primary production. We show that the positive correlation between zooplankton ?15N and temperature is widespread, extending to regions outside of the California Current system. Our findings suggest that interannual variability in zooplankton composition is linked with bottom-up variability in nitrate availability and primary production in the upstream portion of the California Current system. Our results also highlight the potential of integrating biochemical parameters in zooplankton time series for elucidating links between bottom-up processes and the survival of higher trophic levels in the ocean.

El-Sabaawi, Rana W.; Trudel, Marc; Mackas, David L.; Dower, John F.; Mazumder, Asit

2012-11-01

176

Preliminary evaluation of the performance, water use, and current application trends of evaporative coolers in California climates  

SciTech Connect

This paper describes the latest results of an ongoing analysis investigating the potential for evaporative cooling as an energy-efficient alternative to standard air-conditioning in California residences. In particular, the study uses detailed numerical models of evaporative coolers linked with the DOE-2 building energy simulation program to study the issues of indoor comfort, energy and peak demand savings with and without supplemental air-conditioning and consumptive water use. In addition, limited surveys are used to assess the current market availability of evaporative cooling in California, typical contractor practices and costs, and general acceptance of the technology among engineers, contractors, and manufacturers. The results show that evaporative coolers can provide significant energy and peak demand savings in California residences, but the impact of the increased indoor humidity on human comfort remains an unanswered question that requires further research and clarification. Evaluated against ASHRAE comfort standards developed primarily for air-conditioning both direct and two-stage evaporative coolers would not maintain comfort at peak cooling conditions due to excessive humidity. However, using bioclimatic charts that place human comfort at the 80% relative humidity line, the study suggests that direct evaporative coolers will work in mild coastal climates, while two-stage models should provide adequate comfort in Title 24 houses throughout California, except in the Imperial Valley. The study also shows that evaporative coolers will increase household water consumption by less than 6% on an annual basis, and as much as 23% during peak cooling months, and that the increases in water cost are minimal compared to the electricity savings. Lastly, a survey of engineers and contractors revealed generally positive experiences with evaporative coolers, with operational cost savings, improved comfort, unproved air quality as the primary benefits in their use.

Huang, Y.J.; Hanford, J.W.; Wu, H.F.

1992-09-01

177

Recovery strategies for the California clapper rail (Rallus longirostris obsoletus) in the heavily-urbanized San Francisco estuarine ecosystem  

USGS Publications Warehouse

The California clapper rail (Rallus longirostris obsoletus), a Federal- and State-listed endangered marsh bird, has a geographic range restricted to one of the most heavily-urbanized estuaries in the world. The rail population has long been in a state of decline, although the exact contribution of each of the many contributing causes remains unclear. The rail is one of the key targets of emerging plans to conserve and restore tidal marshlands. Reduction of tidal marsh habitat, estimated at 85-95%, has been the major historical cause of rail decline. Increased predation intensity may be the more important present problem, because habitat fragmentation and alteration coupled with the invasion of the red fox have made the remaining populations more vulnerable to predators. Population viability analysis shows that adult survivorship is the key demographic variable; reversals in population fate occur over a narrow range of ecologically realistic values. Analysis of habitat requirements and population dynamics of the clapper rail in the San Francisco Estuary shows that decreased within-marsh habitat quality, particularly reduction of tidal flows and alteration of drainage, is an important barrier to population recovery. Management and restoration activities should emphasize the development of well-channelized high tidal marsh, because this is the key requirement of rail habitat. Developing effective restoration programs depends upon having information that field research will not provide. The effect of spatial pattern of reserves requires accurate estimation of the effects of predation and inter-marsh movement, both of which are practically impossible to measure adequately. It will be necessary to develop and use simulation models that can be applied to geographic data to accomplish this task.

Foin, T.C.; Garcia, E.J.; Gill, R.E.; Culberson, S.D.; Collins, J.N.

1997-01-01

178

Changes in the diet of hake associated with El Nio 1997-1998 in the northern Humboldt Current ecosystem  

NASA Astrophysics Data System (ADS)

Hake (Merluccius gayi peruanus) predation plays an important role in the dynamics of the Humboldt Current ecosystem (HCE). Changes in the hake trophic habits associated with physical variability are expected to impact prey populations and to propagate through the food web. Time series (1995-2002) of (a) stomach contents of hake, (b) biomass estimations of fish prey species of hake, and (c) depth of the 15C isotherm was analysed with the aim of exploring the impacts of El Nio 1997-1998 on the diet of hake. Biomass estimations of fish prey species were used to indicate resource availability, and depth of the 15C isotherm to represent variability associated with the ENSO cycle in the physical environment of hake. The richness of prey species increased during the months when 15C isotherm reached its deepest position, supporting the hypothesis of increased biodiversity (tropicalization) of the HCE during El Nio events. An increased variability in stomach fullness of hake was detected after 1999 which could indicate high heterogeneity in the food supply as a consequence of impacts of the warm event in the biotic community structure of the HCE, a physiological impairment of hake or an effect of the abrupt reduction in the mean total length of hake, postulated as a compensatory response to fishery pressure. Hake can be characterized as an opportunist predator according to the observed changes in its diet during 1995-2002. Overall, the diet of hake in the northern HCE exhibited transitory (e.g. increased richness of prey species in the stomach contents) and medium term (e.g. increased variability in feeding activity) responses associated with El Nio 1997-1998, which should be incorporated both in population dynamics and food web analyses.

Tam, J.; Purca, S.; Duarte, L. O.; Blaskovic, V.; Espinoza, P.

2006-01-01

179

Phytoplankton bloom dynamics in coastal ecosystems: A review with some general lessons from sustained investigation of San Francisco Bay, California  

NASA Astrophysics Data System (ADS)

Phytoplankton blooms are prominent features of biological variability in shallow coastal ecosystems such as estuaries, lagoons, bays, and tidal rivers. Long-term observation and research in San Francisco Bay illustrates some patterns of phytoplankton spatial and temporal variability and the underlying mechanisms of this variability. Blooms are events of rapid production and accumulation of phytoplankton biomass that are usually responses to changing physical forcings originating in the coastal ocean (e.g., tides), the atmosphere (wind), or on the land surface (precipitation and river runoff). These physical forcings have different timescales of variability, so algal blooms can be short-term episodic events, recurrent seasonal phenomena, or rare events associated with exceptional climatic or hydrologic conditions. The biogeochemical role of phytoplankton primary production is to transform and incorporate reactive inorganic elements into organic forms, and these transformations are rapid and lead to measurable geochemical change during blooms. Examples include the depletion of inorganic nutrients (N, P, Si), supersaturation of oxygen and removal of carbon dioxide, shifts in the isotopic composition of reactive elements (C, N), production of climatically active trace gases (methyl bromide, dimethylsulfide), changes in the chemical form and toxicity of trace metals (As, Cd, Ni, Zn), changes in the biochemical composition and reactivity of the suspended particulate matter, and synthesis of organic matter required for the reproduction and growth of heterotrophs, including bacteria, zooplankton, and benthic consumer animals. Some classes of phytoplankton play special roles in the cycling of elements or synthesis of specific organic molecules, but we have only rudimentary understanding of the forces that select for and promote blooms of these species. Mounting evidence suggests that the natural cycles of bloom variability are being altered on a global scale by human activities including the input of toxic contaminants and nutrients, manipulation of river flows, and translocation of species. This hypothesis will be a key component of our effort to understand global change at the land-sea interface. Pursuit of this hypothesis will require creative approaches for distinguishing natural and anthropogenic sources of phytoplankton population variability, as well as recognition that the modes of human disturbance of coastal bloom cycles operate interactively and cannot be studied as isolated processes.

Cloern, James E.

1996-05-01

180

Tidal and residual currents measured by an acoustic doppler current profiler at the west end of Carquinez Strait, San Francisco Bay, California, March to November 1988  

USGS Publications Warehouse

Water-velocity profiles were collected at the west end of Carquinez Strait, San Francisco Bay, California, from March to November 1988, using an acoustic Doppler current profiler (ADCP). These data are a series of 10-minute-averaged water velocities collected at 1-meter vertical intervals (bins) in the 16.8-meter water column, beginning 2.1 meters above the estuary bed. To examine the vertical structure of the horizontal water velocities, the data are separated into individual time-series by bin and then used for time-series plots, harmonic analysis, and for input to digital filters. Three-dimensional graphic renditions of the filtered data are also used in the analysis. Harmonic analysis of the time-series data from each bin indicates that the dominant (12.42 hour or M2) partial tidal currents reverse direction near the bottom, on average, 20 minutes sooner than M2 partial tidal currents near the surface. Residual (nontidal) currents derived from the filtered data indicate that currents near the bottom are pre- dominantly up-estuary during the neap tides and down-estuary during the more energetic spring tides.

Burau, J. R.; Simpson, M. R.; Cheng, R. T.

1993-01-01

181

Decadal Changes in Ozone and Emissions in Central California and Current Issues  

NASA Astrophysics Data System (ADS)

The relationships among ozone, emissions, and meteorology are very complex in central California, and must be well studied and understood in order to facilitate better air quality planning. Factors significantly impacting changes in emissions such as economic and population growth, and adopted emission controls make the matter even more complex. Here we review the history of ozone pollution in central California since the 1970s to plan for the future. Since the 1970s, changes in emissions have been accompanied by likewise dramatic changes in region-to-region differences in air quality. We focus on the coastal San Francisco Bay Area (SFBA) and the inland San Joaquin Valley (SJV). In the 1970s, the SFBA population was approaching 5 million people while the considerably larger and more rural SJV population remained below 2 million. The SFBA population was mostly confined to coastal locations. Peak ozone levels occurred mostly around the population centers and especially over the Bay itself. Hourly average ozone levels routinely approached 160 ppb. These high ozone levels promoted regulations under which SFBA emissions were continuously reduced through the present. By the 1990s, SFBA emissions had been reduced considerably despite the region's population growing to around 6 million. Relative to the 1970s, in 1990s the SFBA had lower peak ozone levels that were shifted to inland locations where much of the population growth was occurring. The SFBA still exceeded the federal 1-hour standard. A rapidly changing economic landscape in the 1970s promoted vast changes in the central California population distribution. In the SJV, the OPEC oil crisis promoted significant development of petroleum resources. Meanwhile, family farms were quickly being replaced with commercial-scale farming operations. The SJV population rapidly expanded to around 3 million people by the early 1990s. During this time, SJV emissions increased considerably, largely from increases in mobile source activities. The previously sparsely populated SJV had quickly developed an even more severe ozone problem than previous years. From 1990 to 2010, the SFBA population expanded to inland locations and then even further into the sheltered SJV. SFBA emissions for ROG and NOx were decreased around 40% and 15%, respectively during this period. High ozone levels became rather infrequent for coastal SFBA locations. During the same period, the SJV population continued to expand rapidly while emissions decreased, especially for ROG. Peak ozone levels remained around 100 ppb and shifted to locations downwind of Fresno and Bakersfield. Central California has experienced perhaps the most dramatic population growth and shifts in the United States during the contemporary economic era. These changes in population have led to some of the most difficult air quality management problems faced by regulators in the United States. Lessons learned from central California highlight the potential benefits of acting early and also the necessity for a long-term, flexible approach using sustained regulations to accompany population changes.

Tanrikulu, S.; Beaver, S.; Soong, S.; Tran, C.; Cordova, J.; Palazoglu, A.

2011-12-01

182

Subtidal currents over the central California slope: Evidence for offshore veering of the undercurrent and for direct, wind-driven slope currents  

USGS Publications Warehouse

In February 1991, an array of six current-meter moorings was deployed for one year across the central California outer shelf and slope. The main line of the array extended 30 km offshore of the shelf break, out to water depths of 1400 m. A more sparsely-instrumented line, displaced 30 km to the northwest, extended 14 km offshore. Though shorter, the northern line spanned similar water depths because the gradient of the topography steepened in the northern region. A poleward flow pattern, typical of the California undercurrent, was seen across both lines in the array over most of the year. The poleward flow was surface intensified. In general, the portion of the undercurrent that crossed the southern line had larger amplitudes and penetrated more deeply into the water column than the portion that crossed the northern line. Transport over the year ranged from 0 to 2.5 Sverdrups (Sv) poleward across the southern line; 0 to 1 Sv poleward across the northern line. We suggest the difference in transport was caused by topographic constraints, which tended to force the poleward flow offshore of the northern measurement sites. The slope of the topography steepened too abruptly to allow the poleward flow to follow isobaths when currents were strong. When current velocities lessened, a more coherent flow pattern was seen across both lines in the array. In general, the poleward flow patterns in the undercurrent were not affected by local winds or by the local alongshore pressure gradient. Nor was a strong seasonal pattern evident. Rather unexpectedly, a small but statistically significant fraction of the current variance over the mid- and outer slope was driven by the surface wind stress. An alongshelf wind stress caused currents to flow along the slope, parallel to the wind field, down to depths of 400 m below the surface and out to distances of 2 Rossby radii past the shelf break. The transfer functions were weak, 3-4 cm/s per dyn cm-2, but comparable to wind-driven current amplitudes of 4-6 cm/s per unit wind stress over the middle shelf. Equatorward, alongshelf winds also caused water from 200-300 m over the slope to upwell onto the shelf as the surface water moved offshore.

Noble, M.A.; Ramp, S.R.

2000-01-01

183

Spartina alterniflora invasions in the Yangtze River estuary, China: An overview of current status and ecosystem effects  

Microsoft Academic Search

The Yangtze River estuary is an important ecoregion. However, Spartina alterniflora, native to North America, was introduced to the estuary in the 1990s through both natural dispersal and humans and now it is a dominant species in the estuarine ecosystems, with its invasions leading to multiple consequences to the estuary. S. alterniflora had great competitive effects on native species, including

Bo Li; Chengz-hang Liao; Xiao-dong Zhang; Hui-li Chen; Qing Wang; Zhong-yi Chen; Xiao-jing Gan; Ji-hua Wu; Bin Zhao; Zhi-jun Ma; Xiao-li Cheng; Li-fen Jiang; Jia-kuan Chen

2009-01-01

184

Biological Implications of Internal Waves and Internal Tidal Bores in the Southern Part of the California Current System  

NASA Astrophysics Data System (ADS)

Internal waves and internal tidal bores have been shown to cause rapid changes in temperature associated with vertical and horizontal displacements of water masses in many settings. Their role in the cross-shore transport of matter and energy implies that internal motions have important biological ramifications, particularly in biogeographic transition zones, such as the Southern California Current. Benthic invertebrates and macroalgae depend greatly on the nearshore pelagic environment for the transport of larvae and nutrients. We present 2 examples of how internal motions may modulate benthic populations in this transition zone by enhancing the transport of larvae or the provision of nutrients from offshore sites to the coast. At two sites along the Baja California peninsula, high-frequency variability in thermal structure and horizontal flows were observed. Physical observations show episodes (lasting about 1 h) of rapid variations (every 1 to 5 min) in horizontal flows and temperature in the nearshore water column. We show that the timing and intensity of larval settlement, as well as the residence of cold nutrient - rich water on the shelf, is related with internal motions just offshore. Variability in the direction from which these perturbations propagate may determine small-scale spatial patterns in demography of benthic populations. We discuss the importance of these events in modulating benthic invertebrate and macroalgal populations and how climate change in this transition zone may have important biological consequences via changes in thermocline depth and its subsequent impact on the occurrence of internal motions.

Ladah, L. B.; Leichter, J. J.; Tapia, F. J.

2007-05-01

185

Effect of coastal-trapped waves and wind on currents and transport in the Gulf of California  

NASA Astrophysics Data System (ADS)

pressure (SsP) observations from stations inside and outside of the Gulf of California (GC) are used to analyze the relationship between low-frequency currents, temperature, and transport inside the GC and intraseasonal coastal-trapped waves (CTWs), which propagate poleward along the coast toward the GC. Correlation functions and coherences of SsP stations were consistent with intraseasonal CTWs splitting in two at the mouth of the gulf: one part enters the gulf, propagates around the gulf, and eventually, toward the mouth, and another part that appears to "jump" the mouth of the gulf and travels poleward along the west coast of the peninsula. The correlation and coherence estimates of SsP at Manzanillo with currents showed that downwelling CTWs generated along-gulf current anomalies toward the head of the gulf at the mainland shelf of the mouth, whereas at Ballenas Channel sill (San Lorenzo sill) these waves generated current anomalies toward the mouth near the surface (bottom). At the San Lorenzo (SL) sill, downwelling CTWs increased the near-bottom (400 m) temperature and reduced the bottom transport of deep, fresher, and colder water that flows toward the head of the gulf. Cross-Calibrated Multiplatform winds were used to investigate their relationship with currents. The first empirical orthogonal function of the along-gulf wind stress showed that wind blowing toward the head of the gulf generated a reduction of bottom transport toward the head of the gulf through the SL sill, and intensified surface geostrophic current fluctuations toward the head of the gulf. There was also significant correlation between inflow bottom transport and outflow surface geostrophic velocities averaged across the gulf, consistent with the exchange pattern for the Northern Gulf.

Gutirrez, Manuel O.; Lpez, Manuel; Candela, Julio; Castro, Rubn.; Mascarenhas, Affonso; Collins, Curtis A.

2014-08-01

186

Biogeochemical Response to Mesoscale Physical Forcing in the California Current System  

NASA Technical Reports Server (NTRS)

In the first part of the project, we investigated the local response of the coastal ocean ecosystems (changes in chlorophyll, concentration and chlorophyll, fluorescence quantum yield) to physical forcing by developing and deploying Autonomous Drifting Ocean Stations (ADOS) within several mesoscale features along the U.S. west coast. Also, we compared the temporal and spatial variability registered by sensors mounted in the drifters to that registered by the sensors mounted in the satellites in order to assess the scales of variability that are not resolved by the ocean color satellite. The second part of the project used the existing WOCE SVP Surface Lagrangian drifters to track individual water parcels through time. The individual drifter tracks were used to generate multivariate time series by interpolating/extracting the biological and physical data fields retrieved by remote sensors (ocean color, SST, wind speed and direction, wind stress curl, and sea level topography). The individual time series of the physical data (AVHRR, TOPEX, NCEP) were analyzed against the ocean color (SeaWiFS) time-series to determine the time scale of biological response to the physical forcing. The results from this part of the research is being used to compare the decorrelation scales of chlorophyll from a Lagrangian and Eulerian framework. The results from both parts of this research augmented the necessary time series data needed to investigate the interactions between the ocean mesoscale features, wind, and the biogeochemical processes. Using the historical Lagrangian data sets, we have completed a comparison of the decorrelation scales in both the Eulerian and Lagrangian reference frame for the SeaWiFS data set. We are continuing to investigate how these results might be used in objective mapping efforts.

Niiler, Pearn P.; Letelier, Ricardo; Moisan, John R.; Marra, John A. (Technical Monitor)

2001-01-01

187

Numerical Simulation of Recent Turbidity Currents in the Monterey Canyon System, Offshore California  

Microsoft Academic Search

The method of computational fluid dynamics (CFD) has been used, in the form of a 3D numerical model (Flow- 3D), to perform a full-scale simulation of turbidity currents measured in December 2002 by three moorings in the Soquel and Monterey canyons. The model was verified by simulation of laboratory flows, and was upscaled to the Monterey Canyon system on the

S. Heimsund; J. Xu; W. Nemec

2007-01-01

188

COBRA ADMINISTRATION CONEXIS currently administers the COBRA process for the University of California (UC). The following is a list of qualifying events and the  

E-print Network

COBRA ADMINISTRATION CONEXIS currently administers the COBRA process for the University of California (UC). The following is a list of qualifying events and the required actions for each. If you need assistance regarding any of these qualifying events, please contact Campus Shared Services at (510

Walker, Matthew P.

189

Methane budget of the down-current plume from Coal Oil Point seep field, Santa Barbara Channel, California  

NASA Astrophysics Data System (ADS)

Previous research indicates that 5.5-9.6 x 106 mol/d (90-150 t/d) of methane are emitted from the seafloor into the coastal ocean near Coal Oil Point (COP), Santa Barbara Channel (SBC), California. Methane concentrations and biologically-mediated oxidation rates were quantified at 12 stations in a 198 km2 area down-current from COP during the SEEPS"07-Cruise with the R/V Atlantis. A ship-board Acoustic Doppler Current Profiler (ADCP) recorded current velocity patterns simultaneously with water sampling. The observed methane distribution matches the cyclonic gyre which is the normal current flow in this part of the Santa Barbara Channel - pushing water to the shore near the seep field and then broadening the plume while the water turns offshore further from the source. A methane budget was calculated using a box model, with budget terms including methane burden, sea-air flux, oxidative loss, and flux in and out of the 51 km3 box. The results indicate a 0.6% loss via sea-air exchange and a 1.5% loss due to microbial oxidation. The majority of the methane is advected in and out of the box. This data enables a calculation of the amount of dissolved methane emitted from the COP seep field, and when combined with published measurements of bubble flux, allows for a revision of the total methane flux from the COP seeps. Revised estimates for the dissolved methane flux for COP are 5.5 x 106 mol/d, raising the total COP methane release to 7.4-11.5 x 106 mol/d (120-180 t/d). These results represent a snapshot, but serve as a base for the first complete dissolved methane budget of the water column above a seep site in the marine realm.

Mau, S.; Heintz, M.; Valentine, D. L.

2008-12-01

190

Ecosystem Explorations  

NSDL National Science Digital Library

The Ecosystem Explorations curriculum includes eleven classroom lessons. The lessons are divided into two sections--Understanding Ecosystems and Human Connections to Ecosystems. The curriculum incorporates scientific inquiry skills, cooperative l

Gunckel, Kristen L.

1999-09-01

191

Water Management Adaptations for Aquatic Ecosystem Services Under a Changing Climate. Analytical Framework and Case Study for Chinook Salmon in California  

NASA Astrophysics Data System (ADS)

Spring-run Chinook salmon (Oncorhynchus tshawytscha) are vulnerable to climate change because, before spawning in autumn, adults hold in river pools where temperature increases during summer. As these species naturally experience temperatures close to tolerable thresholds, climate-induced flow and temperature changes can increase their vulnerability. Our objective was to assemble an analytical framework to assess temperature and streamflow thresholds that would lead to critical reductions in spring-run Chinook salmon abundance, and to evaluate management adaptations to ameliorate these impacts. The analytical framework coupled climate data with watershed hydrology and salmon population dynamics models. We used WEAP, an integrated watershed hydrology, water management, and temperature model; and SALMOD, a spatially explicit and size/stage structured model that predicts population dynamics of salmon in freshwater systems. The models simulated weekly mean streamflow, temperature, and salmon abundance in Butte Creek, California. We calibrated and validated the models to adequately fit historical data. With the analytical framework built, we used bias-corrected and spatially downscaled climate data from six General Circulation Models and two emission scenarios for the period 2010 - 2099 to run the two linked models, and generated a range of potential future outcomes. WEAP predicted that summer base flows were lower, and water temperatures were higher for climate scenarios vs. historical conditions. SALMOD predicted increased summer thermal mortality of adult salmon; the population was predicted to decline for all climate scenarios and model combinations. We tested management adaptations, including cessation of water diverted for power production, and storage of cold reservoir water upstream for release during hot weather. Some adaptations resulted in cooler temperatures, more adults surviving to spawn, and extended population survival time. The coupled models, together with climate data, constitute a framework able to predict streamflow- and temperature-related mortality of spring-run Chinook salmon, and to evaluate water management adaptations to ameliorate negative climate impacts on fish in current or future scenarios.

Escobar, M.; Mosser, C. M.; Thompson, L. C.; Purkey, D.; Moyle, P. B.

2010-12-01

192

Anomalously warm July 2005 in the northern California Current: Historical context and the significance of cumulative wind stress  

NASA Astrophysics Data System (ADS)

In the northern California Current, the onset of the 2005 upwelling season was five weeks later than usual, and well-established upwelling with a cold surface signature did not occur until about seven weeks after this. As part of the joint US-Canada Pacific hake survey, from 14-16 July 2005 we occupied the Newport Hydrographic line at 44.65N, from the Oregon coast to 83 km offshore. Instead of the cold surface layer expected in July, we observed anomalously warm water. For example, 10-m temperature at the shelf station NH-5 was the warmest ever recorded in July at this location: 6.2C above average, with observations back to 1961. We explore the pivotal role played by cumulative (time-integrated) wind forcing in the development of upwelling, in both 2005 and previous years. We find that 80% of July surface layer (0-30 m) interannual temperature variance can be explained by cumulative upwelling index from the spring transition.

Pierce, Stephen D.; Barth, John A.; Thomas, Rebecca E.; Fleischer, Guy W.

2006-10-01

193

Estimating suspended solids concentrations from backscatter intensity measured by acoustic Doppler current profiler in San Francisco Bay, California  

USGS Publications Warehouse

The estimation of mass concentration of suspended solids is one of the properties needed to understand the characteristics of sediment transport in bays and estuaries. However, useful measurements or estimates of this property are often problematic when employing the usual methods of determination from collected water samples or optical sensors. Analysis of water samples tends to undersample the highly variable character of suspended solids, and optical sensors often become useless from biological fouling in highly productive regions. Acoustic sensors, such as acoustic Doppler current profilers that are now routinely used to measure water velocity, have been shown to hold promise as a means of quantitatively estimating suspended solids from acoustic backscatter intensity, a parameter used in velocity measurement. To further evaluate application of this technique using commercially available instruments, profiles of suspended solids concentrations are estimated from acoustic backscatter intensity recorded by 1200- and 2400-kHz broadband acoustic Doppler current profilers located at two sites in San Francisco Bay, California. ADCP backscatter intensity is calibrated using optical backscatterance data from an instrument located at a depth close to the ADCP transducers. In addition to losses from spherical spreading and water absorption, calculations of acoustic transmission losses account for attenuation from suspended sediment and correction for nonspherical spreading in the near field of the acoustic transducer. Acoustic estimates of suspended solids consisting of cohesive and noncohesive sediments are found to agree within about 8-10% (of the total range of concentration) to those values estimated by a second optical backscatterance sensor located at a depth further from the ADCP transducers. The success of this approach using commercially available Doppler profilers provides promise that this technique might be appropriate and useful under certain conditions in spite of some theoretical limitations of the method. ?? 2004 Elsevier B.V. All rights reserved.

Gartner, J.W.

2004-01-01

194

Analysis of projected water availability with current basin management plan, Pajaro Valley, California  

NASA Astrophysics Data System (ADS)

The projection and analysis of the Pajaro Valley Hydrologic Model (PVHM) 34 years into the future using MODFLOW with the Farm Process (MF-FMP) facilitates assessment of potential future water availability. The projection is facilitated by the integrated hydrologic model, MF-FMP that fully couples the simulation of the use and movement of water from precipitation, streamflow, runoff, groundwater flow, and consumption by natural and agricultural vegetation throughout the hydrologic system at all times. MF-FMP allows for more complete analysis of conjunctive-use water-resource systems than previously possible with MODFLOW by combining relevant aspects of the landscape with the groundwater and surface-water components. This analysis is accomplished using distributed cell-by-cell supply-constrained and demand-driven components across the landscape within water-balance subregions (WBS) comprised of one or more model cells that can represent a single farm, a group of farms, watersheds, or other hydrologic or geopolitical entities. Analysis of conjunctive use would be difficult without embedding the fully coupled supply-and-demand into a fully coupled simulation, and are difficult to estimate a priori. The analysis of projected supply and demand for the Pajaro Valley indicate that the current water supply facilities constructed to provide alternative local sources of supplemental water to replace coastal groundwater pumpage, but may not completely eliminate additional overdraft. The simulation of the coastal distribution system (CDS) replicates: 20 miles of conveyance pipeline, managed aquifer recharge and recovery (MARR) system that captures local runoff, and recycled-water treatment facility (RWF) from urban wastewater, along with the use of other blend water supplies, provide partial relief and substitution for coastal pumpage (aka in-lieu recharge). The effects of these Basin Management Plan (BMP) projects were analyzed subject to historical climate variations and assumptions of 2009 urban water demand and land use. Water supplied directly from precipitation, and indirectly from reuse, captured local runoff, and groundwater is necessary but inadequate to satisfy agricultural demand without coastal and regional storage depletion that facilitates seawater intrusion. These facilities reduce potential seawater intrusion by about 45% with groundwater levels in the four regions served by the CDS projected to recover to levels a few feet above sea level. The projected recoveries are not high enough to prevent additional seawater intrusion during dry-year periods or in the deeper aquifers where pumpage is greater. While these facilities could reduce coastal pumpage by about 55% of the historical 2000-2009 pumpage for these regions, and some of the water is delivered in excess of demand, other coastal regions continue to create demands on coastal pumpage that will need to be replaced to reduce seawater intrusion. In addition, inland urban and agricultural demands continue to sustain water levels below sea level causing regional landward gradients that also drive seawater intrusion. Seawater intrusion is reduced by about 45% but it supplies about 55% of the recovery of groundwater levels in the coastal regions served by the CDS. If economically feasible, water from summer agricultural runoff and tile-drain returnflows could be another potential local source of water that, if captured and reused, could offset the imbalance between supply and demand as well as reducing discharge of agricultural runoff into the National Marine Sanctuary of Monterey Bay. A BMP update (2012) identifies projects and programs that will fund a conservation program and will provide additional, alternative water sources to reduce or replace coastal and inland pumpage, and to replenish the aquifers with managed aquifer recharge in an inland portion of the Pajaro Valley.

Hanson, R. T.; Lockwood, B.; Schmid, Wolfgang

2014-11-01

195

Freshwater conservation options for a changing climate in California's Sierra Nevada  

E-print Network

Freshwater conservation options for a changing climate in California's Sierra Nevada Joshua H and the environment, during which regional freshwater ecosystems have experienced extirpations of anadromous fishes and altering flows. Freshwater conservation efforts currently rely on a patchwork of legal and regulatory

Schladow, S. Geoffrey

196

Variability in biomass yields of large marine ecosystems (LMEs) during climate change  

SciTech Connect

Results of ecosystem studies relating to variations in biomass yields are examined in relation to principle driving forces including climate change, coastal pollution, habitat degradation, and overexploitation of living marine resources. Among the ecosystems compared with regard to the different prime driving forces, affecting sustainability of biomass yields, are the Black Sea, the Baltic Sea, the Barents Sea, Kuroshio Current, California Current, Great Barrier Reef, Gulf of Mexico, Yellow Sea, Icelandic Shelf, and Northeast US Shelf ecosystems. The designation and management of large marine ecosystems (LMEs) is, at present, an evolving scientific and geopolitical process. Sufficient progress has been made to allow for useful comparisons among different processes influencing large-scale changes in the biomass yields of LMEs. The most severely impacted LMEs are off the coasts of the continents.

Sherman, K. (NOAA, NMFS, NEFSC, Narragansett Lab., RI (United States))

1993-06-01

197

Our current understanding of lake ecosystem response to climate change: What have we really learned from the north temperate deep lakes?  

Microsoft Academic Search

Climatic change is recognized as an important factor capable of influencing the structural properties of aquatic ecosystems. Lake ecosystems are particularly sensitive to climate change. Several long time-series studies have shown close coupling between climate, lake thermal properties and individual organism physiology, population abundance, community structure, and food-web structure. Understanding the complex interplay between climate, hydrological variability, and ecosystem structure

Yuko Shimoda; M. Ekram Azim; Gurbir Perhar; Maryam Ramin; Melissa A. Kenney; Somayeh Sadraddini; Alex Gudimov; George B. Arhonditsis

2011-01-01

198

Carbon and Nitrogen Isotopes from Top Predator Amino Acids Reveal Rapidly Shifting Ocean Biochemistry in the Outer California Current  

PubMed Central

Climatic variation alters biochemical and ecological processes, but it is difficult both to quantify the magnitude of such changes, and to differentiate long-term shifts from inter-annual variability. Here, we simultaneously quantify decade-scale isotopic variability at the lowest and highest trophic positions in the offshore California Current System (CCS) by measuring ?15N and ?13C values of amino acids in a top predator, the sperm whale (Physeter macrocephalus). Using a time series of skin tissue samples as a biological archive, isotopic records from individual amino acids (AAs) can reveal the proximate factors driving a temporal decline we observed in bulk isotope values (a decline of ?1 ) by decoupling changes in primary producer isotope values from those linked to the trophic position of this toothed whale. A continuous decline in baseline (i.e., primary producer) ?15N and ?13C values was observed from 1993 to 2005 (a decrease of ?4 for ?15N source-AAs and 3 for ?13C essential-AAs), while the trophic position of whales was variable over time and it did not exhibit directional trends. The baseline ?15N and ?13C shifts suggest rapid ongoing changes in the carbon and nitrogen biogeochemical cycling in the offshore CCS, potentially occurring at faster rates than long-term shifts observed elsewhere in the Pacific. While the mechanisms forcing these biogeochemical shifts remain to be determined, our data suggest possible links to natural climate variability, and also corresponding shifts in surface nutrient availability. Our study demonstrates that isotopic analysis of individual amino acids from a top marine mammal predator can be a powerful new approach to reconstructing temporal variation in both biochemical cycling and trophic structure. PMID:25329915

Ruiz-Cooley, Rocio I.; Koch, Paul L.; Fiedler, Paul C.; McCarthy, Matthew D.

2014-01-01

199

Variability and trends of ocean acidification in the Southern California Current System: A time series from Santa Monica Bay  

NASA Astrophysics Data System (ADS)

We investigate the temporal variability and trends of pH and of the aragonite saturation state, ?arag, in the southern California Current System on the basis of a 6 year time series from Santa Monica Bay, using biweekly observations of dissolved inorganic carbon and combined calculated and measured alkalinity. Median values of pH and ?arag in the upper 20 m are comparable to observations from the subtropical gyres, but the temporal variability is at least a factor of 5 larger, primarily driven by short-term upwelling events and mesoscale processes. ?arag and pH decrease rapidly with depth, such that the saturation horizon is reached already at 130 m, on average, but it occasionally shoals to as low as 30 m. No statistically significant linear trends emerge in the upper 100 m, but ?arag and pH decrease, on average, at rates of -0.0090.006 yr-1 and -0.0040.003 yr-1 in the 100-250 m depth range. These are somewhat larger, but not statistically different from the expected trends based on the recent increase in atmospheric CO2. About half of the variability in the deseasonalized data can be explained by the El Nio Southern Oscillation, with warm phases (El Nio) being associated with above normal pH and ?arag. The observed variability and trend in ?arag and pH is well captured by a multiple linear regression model on the basis of a small number of readily observable independent variables. This permits the estimation of these variables for related sites in the region.

Leinweber, A.; Gruber, N.

2013-07-01

200

Florida Ecosystems  

NSDL National Science Digital Library

Provided by FICUS (the Florida Internet Center for Understanding Sustainability) and the University of South Florida, this gem of a site covers Florida's native upland, freshwater, and marine ecosystems. Streamlined in organization but solid in content, Florida Ecosystems offers introductory information and photographic images of a dozen ecosystems, ranging from Pine Flatwoods and Dry Prairies to Mangrove Swamps and Coral Reefs. For students and educators interested in subtropical ecosystems, this is a nice place to start.

201

Ecosystem Jenga!  

ERIC Educational Resources Information Center

To give students a tangible model of an ecosystem and have them experience what could happen if a component of that ecosystem were removed; the authors developed a hands-on, inquiry-based activity that visually demonstrates the concept of a delicately balanced ecosystem through a modification of the popular game Jenga. This activity can be

Umphlett, Natalie; Brosius, Tierney; Laungani, Ramesh; Rousseau, Joe; Leslie-Pelecky, Diandra L.

2009-01-01

202

Ecosystem Journalism  

ERIC Educational Resources Information Center

If the organisms in a prairie ecosystem created a newspaper, what would it look like? What important news topics of the ecosystem would the organisms want to discuss? Imaginative and enthusiastic third-grade students were busy pondering these questions as they tried their hands at "ecosystem journalism." The class had recently completed a study of

Robertson, Amy; Mahlin, Kathryn

2005-01-01

203

Use of marine sanctuaries by far-ranging predators: commuting flights to the California Current System by breeding Hawaiian albatrosses  

Microsoft Academic Search

Quantifying the dispersion and habitats of far-ranging seabirds, turtles, and cetaceans is essential to assess whether zoning strategies can help protect upper- trophic marine predators. In this paper, we focus on Black-footed Albatross (Phoebastria nigripes) use of three US national marine sanctuaries off central California: Cordell Bank, Gulf of the Farallones, and Monterey Bay. We assessed the significance of these

K. D. HYRENBACH; C. KEIPER; S. G. ALLEN; D. G. AINLEY; D. J. ANDERSON

2006-01-01

204

Spatial analysis of plague in California: niche modeling predictions of the current distribution and potential response to climate change  

PubMed Central

Background Plague, caused by the bacterium Yersinia pestis, is a public and wildlife health concern in California and the western United States. This study explores the spatial characteristics of positive plague samples in California and tests Maxent, a machine-learning method that can be used to develop niche-based models from presence-only data, for mapping the potential distribution of plague foci. Maxent models were constructed using geocoded seroprevalence data from surveillance of California ground squirrels (Spermophilus beecheyi) as case points and Worldclim bioclimatic data as predictor variables, and compared and validated using area under the receiver operating curve (AUC) statistics. Additionally, model results were compared to locations of positive and negative coyote (Canis latrans) samples, in order to determine the correlation between Maxent model predictions and areas of plague risk as determined via wild carnivore surveillance. Results Models of plague activity in California ground squirrels, based on recent climate conditions, accurately identified case locations (AUC of 0.913 to 0.948) and were significantly correlated with coyote samples. The final models were used to identify potential plague risk areas based on an ensemble of six future climate scenarios. These models suggest that by 2050, climate conditions may reduce plague risk in the southern parts of California and increase risk along the northern coast and Sierras. Conclusion Because different modeling approaches can yield substantially different results, care should be taken when interpreting future model predictions. Nonetheless, niche modeling can be a useful tool for exploring and mapping the potential response of plague activity to climate change. The final models in this study were used to identify potential plague risk areas based on an ensemble of six future climate scenarios, which can help public managers decide where to allocate surveillance resources. In addition, Maxent model results were significantly correlated with coyote samples, indicating that carnivore surveillance programs will continue to be important for tracking the response of plague to future climate conditions. PMID:19558717

Holt, Ashley C; Salkeld, Daniel J; Fritz, Curtis L; Tucker, James R; Gong, Peng

2009-01-01

205

Freshwater Ecosystems  

NSDL National Science Digital Library

In this activity, learners create a freshwater ecosystem in a large plastic bottle. Learners cut and prepare bottles, then fill with water, aquatic plants, snails and fish. Learners observe their mini-ecosystem over time to see what changes--such as the color of the water, the water temperature, plant growth, and behavior and/or population of the snails or fish. The activity serves as a model for larger freshwater ecosystems such as ponds, lakes, rivers, streams, wetlands, reservoirs and groundwater.

Jersey, New; Center, Liberty S.; Coalition, New J.

2006-01-01

206

CALIFORNIA AGRICULTURE, NOVEMBERDECEMBER 2001 47 Carefully timed burning  

E-print Network

ovata) and barb goatgrass are invasive primarily in disturbed and undisturbed grasslands and pastures annual grass that is rapidly invading California's grassland ecosystems. No effective control strategies

Merenlender, Adina

207

Coral Ecosystems  

NSDL National Science Digital Library

Why study coral ecosystems? Having survived millions of years, coral reefs are among the oldest and most diverse ecosystems on earth. Learning about coral ecosystems encompasses many of the 9-12 grade science curriculum standards. Life cycles of organisms, biological structure and function of organisms, and the behaviors and adaptations of organisms to their environment are all topics easily studied through a focus on coral reefs. All populations in this ecosystem are interdependent and part of a global food web. Healthy coral ecosystems are important to the humans, plants, fish, and other organisms that depend on them. However, the increasing impact of climate changes and human activities is endangering the very survival of these ecosystems. Pollution, habitat loss, invasive species, and diseases are all threats to the survival of coral ecosystems around the globe. Learning about them- "their fragility and value"- will help students understand what is needed to protect them. This SciGuide highlights outstanding NOAA resources, such as online tutorials and complete, hands-on, inquiry based lesson plans from the National Ocean Services. These resources address three areas. First, students can study the biology of the coral organism, learning about types of coral and where they are found. Next, resources focus on the populations, habitat, and dynamics of coral ecosystems. Finally, teachers and students, through online data sources and activities, learn about conservation of our coral ecosystems. Natural threats, human disturbances, and the benefits of coral protection focus students on the real world importance of science learning.

National Science Teachers Association (NSTA)

2006-06-01

208

Effects of Recent Debris Flows on Stream Ecosystems and Food Webs in Small Watersheds in the Central Klamath Mountains, NW California  

NASA Astrophysics Data System (ADS)

Debris flows are common erosional processes in steep mountain areas throughout the world, but little is known about the long-term ecological effects of debris flows on stream ecosystems. Based on debris flow histories that were developed for each of ten tributary basins, we classified channels as having experienced recent (1997) or older (pre-1997) debris flows. Of the streams classified as older debris flow streams, three streams experienced debris flows during floods in 1964 or 1974, while two streams showed little or no evidence of debris flow activity in the 20th century. White alder (Alnus rhombifolia) was the dominant pioneer tree species in recent debris flow streams, forming localized dense patches of canopy cover. Maximum temperatures and daily temperature ranges were significantly higher in recent debris flow streams than in older debris flow streams. Debris flows resulted in a shift in food webs from allochthonous to autochthonous energy sources. Primary productivity, as measured by oxygen change during the day, was greater in recent debris flow streams, resulting in increased abundances of grazers such as the armored caddisfly Glossosoma spp. Detritivorous stoneflies were virtually absent in recent debris flow streams because of the lack of year-round, diverse sources of leaf litter. Rainbow trout (Oncorhynchus mykiss) were abundant in four of the recent debris flow streams. Poor recolonizers, such as the Pacific giant salamander (Dicamptodon tenebrosus), coastal tailed frog (Ascaphus truei), and signal crayfish (Pacifistacus leniusculus), were virtually absent in recent debris flow streams. Forest and watershed managers should consider the role of forest disturbances, such as road networks, on debris flow frequency and intensity, and the resulting ecological effects on stream ecosystems.

Cover, M. R.; de La Fuente, J.

2008-12-01

209

AQUATIC ECOSYSTEMS,  

EPA Science Inventory

Aquatic ecosystems are a vital part of the urban water cycle (and of urban areas more broadly), and, if healthy, provide a range of goods and services valued by humans (Meyer 1997). For example, aquatic ecosystems (e.g., rivers, lakes, wetlands) provide potable water, food resou...

210

Comparative bioaccumulation of trace metals using six filter feeder organisms in a coastal lagoon ecosystem (of the central-east Gulf of California).  

PubMed

The Tobari Lagoon, located in the central-east coast of the Gulf of California, receives effluents from the Yaqui Valley, one of the most extensive agricultural areas of Mxico. The Tobari Lagoon also receives effluents from nearby shrimp farms and untreated municipal sewage. Surface sediment samples and six different species of filter feeders (Crassostrea corteziensis, Crassostrea gigas, Chione gnidia, Anadara tuberculosa, Chione fluctifraga, and Fistulobalanus dentivarians) were collected during the dry and the rainy seasons and analyzed to determine concentrations of cadmium (Cd), copper (Cu), mercury (Hg), lead (Pb), and zinc (Zn). Seasonal variations in metal concentrations in sediment were evident, especially for Cd, Cu, Hg, and Zn. The total and bioavailable concentrations of the five metals are not elevated in comparison to other areas around the world. The percentages of bioavailable respect to total concentrations of the metals varied from 0.6 % in Hg to 50.2 % for Cu. In the organisms, Hg showed the lowest concentrations (ranged from 0.22 to 0.65 ?g/g) while Zn showed the highest (ranged from 36.6 to 1,702 ?g/g). Linear correlations between the levels of Cu, Pb, and Zn in the soft tissues of C. fluctifraga and C. gnidia, and A. tuberculosa and C. gnidia were found. Seasonal and interspecies variations in the metal levels in filter feeders were found; F. dentivarians, C. corteziensis, and C. gigas exhibited the highest levels, could be used as biomonitors of metals contamination in this area. PMID:22527455

Jara-Marini, M E; Tapia-Alcaraz, J N; Dumer-Gutirrez, J A; Garca-Rico, L; Garca-Hernndez, J; Pez-Osuna, F

2013-02-01

211

[Vaginal ecosystem].  

PubMed

The vagina is original biotype with its own ecosystem, according to medical ecology science. This ecosystem has dynamic, but very unstable equilibrium. Disturb equilibrium is known as a disbiosys. It was discussed different components of this ecosystem: morphology of vaginal walls, vaginal liquidity, lacto-acid and residental flora, "invader" microorganisms, vaginal acidity, immune processes. It was shared our own experience with medicine Polygynax, remedy of Laboratoire Innotech International (Paris, France). Polygynax has such an advantage - rapidly restore disturbed ecological equlibrium in case of bacterial vulvovaginitis, caused mainly of intestine pathogenic flora. PMID:15673027

Karag'ozov, I; Shopova, E; Andreeva, P

2004-01-01

212

Ecosystem Valuation  

NSDL National Science Digital Library

Developed as a collaborative project of the US Department of Agriculture, Natural Resource Conservation Service, US Department of Commerce, NOAA-Sea Grant Office, and University of Maryland, Center for Environmental Science, this new Website examines how economists attempt to assign values to ecosystem services. The site is well organized and outlines general and specific topics under the following sections: The Big Picture, Essentials of Ecosystem Valuation, Dollar-based Ecosystem Valuation Methods, Ecosystem Benefit Indicators, and Links. Topics are explained in terms that laypersons will understand (a glossary is also provided) but without compromising the quality of information. Anyone interested in learning more about this controversial but increasingly important area will find this site an excellent starting point.

213

COMPARISON OF RECORDING CURRENT METERS USED FOR MEASURING VELOCITIES IN SHALLOW WATERS OF SAN FRANCISCO BAY, CALIFORNIA.  

USGS Publications Warehouse

The authors determine the feasibility of collecting reliable current-meter data in shallow water under natural conditions. The study involved field testing four types of recording current meters (different speed sensors) and comparing data recorded by the meters under different field conditions. Speeds recorded by the current meters at slack water and during maximum flows were compared during calm and windy conditions at various tide levels.

Gartner, Jeffrey, W.; Oltmann, Richard, N.

1985-01-01

214

ECOSYSTEM HEALTH: ENERGY INDICATORS  

EPA Science Inventory

1. Ecosystem Health and Ecological Integrity 2. Historical Background on Ecosystem Health 3. Energy Systems Analysis, Health and Emergy 4. Energy and Ecosystems 5. Direct Measures of Ecosystem Health 6. Indirect Measures of Ecosystem Health...

215

STATE OF CALIFORNIA THE RESOURCES AGENCY ARNOLD SCHWARZENEGGER, Governor CALIFORNIA ENERGY COMMISSION  

E-print Network

STATE OF CALIFORNIA THE RESOURCES AGENCY ARNOLD SCHWARZENEGGER, Governor CALIFORNIA ENERGY" with "project owner" for consistency with the Commission's current administrative format. It is Energy, 2005, the California Energy Commission received a petition from the Bottle Rock Power Corporation (BRPC

216

STATE OF CALIFORNIA --NATURAL RESOURCES AGENCY EDMUND G. BROWN JR., Governor CALIFORNIA ENERGY COMMISSION  

E-print Network

STATE OF CALIFORNIA -- NATURAL RESOURCES AGENCY EDMUND G. BROWN JR., Governor CALIFORNIA ENERGY outlines the current amount of renewable energy development on state properties, challenges COMMISSION 1516 Ninth Street Sacramento, California 95814 Main website: www.energy.ca.gov Notice

217

Connections Among the Spatial and Temporal Structures in Tidal Currents, Internal Bores, and Surficial Sediment Distributions Over the Shelf off Palos Verdes, California  

USGS Publications Warehouse

The topography of the Continental Shelf in the central portion of the Southern California Bight has rapid variations over relatively small spatial scales. The width of the shelf off the Palos Verdes peninsula, just northwest of Los Angeles, California, is only 1 to 3 km. About 7 km southeast of the peninsula, the shelf within San Pedro Bay widens to about 20 km. In 2000, the Los Angeles County Sanitation District began deploying a dense array of moorings in this complex region of the central Southern California Bight to monitor local circulation patterns. Moorings were deployed at 13 sites on the Palos Verdes shelf and within the northwestern portion of San Pedro Bay. At each site, a mooring supported a string of thermistors and an adjacent bottom platform housed an Acoustic Doppler Current Profiler. These instruments collected vertical profiles of current and temperature data continuously for one to two years. The variable bathymetry in the region causes rapid changes in the amplitudes and spatial structures of barotropic tidal currents, internal tidal currents, and in the associated nonlinear baroclinic currents that occur at approximate tidal frequencies. The largest barotropic tidal constituent is M2, the principal semidiurnal tide. The amplitude of this tidal current changes over fairly short along-shelf length scales. Tidal-current amplitudes are largest in the transition region between the two shelves; they increase from about 5 cm/s over the northern San Pedro shelf to nearly 10 cm/s on the southern portion of the Palos Verdes Shelf. Tidal-current amplitudes are then reduced to less than 2 cm/s over the very narrow section of the northern Palos Verdes shelf that lies just 6 km upcoast of the southern sites. Models suggest that the amplitude of the barotropic M2 tidal currents, which propagate toward the northwest primarily as a Kelvin wave, is adjusting to the short topographic length scales in the region. Semidiurnal sea-level oscillations are, as expected, independent of these topographic variations; they have a uniform amplitude and phase structure over the entire region. Because the cross-shelf angle of the seabed over most of the Palos Verdes shelf is 1 to 3 degrees, which is critical for the local generation and/or enhancement of nonlinear characteristics in semidiurnal internal tides, some internal tidal-current events have strong asymmetric current oscillations that are enhanced near the seabed. Near-bottom currents in these events are directed primarily offshore with amplitudes that exceed 30 cm/s. The spatial patterns in these energetic near-bottom currents have fairly short-length scales. They are largest over the inner shelf and in the transition region between the Palos Verdes and San Pedro shelves. This spatial pattern is similar to that found in the barotropic tidal currents. Because these baroclinic currents have an approximate tidal frequency, an asymmetric vertical structure, and a somewhat stable phase, they can produce a non-zero depth-mean flow for periods of a few months. These baroclinic currents can interact with the barotropic tidal current and cause an apparent increase (or decrease) in the estimated barotropic tidal-current amplitude. The apparent amplitude of the barotropic tidal current may change by 30 to 80 percent or more in a current record that is less than three months long. The currents and surficial sediments in this region are in dynamic equilibrium in that the spatial patterns in bottom stresses generated by near-bed currents from surface tides, internal tides, and internal bores partly control the spatial patterns in the local sediments. Coarser sediments are found in the regions with enhanced bottom stresses (that is, over the inner shelf and in the region between the Palos Verdes and San Pedro shelves). Finer sediments are found over the northwestern portion of the Palos Verdes shelf, where near-bottom currents are relatively weak. The nonlinear asymmetries in the i

Noble, Marlene A.; Rosenberger, Kurt J.; Xu, Jingping; Signell, Richard P.; Steele, Alex

2009-01-01

218

Obscuring ecosystem function with application of the ecosystem services concept.  

PubMed

Conservationists commonly have framed ecological concerns in economic terms to garner political support for conservation and to increase public interest in preserving global biodiversity. Beginning in the early 1980s, conservation biologists adapted neoliberal economics to reframe ecosystem functions and related biodiversity as ecosystem services to humanity. Despite the economic success of programs such as the Catskill/Delaware watershed management plan in the United States and the creation of global carbon exchanges, today's marketplace often fails to adequately protect biodiversity. We used a Marxist critique to explain one reason for this failure and to suggest a possible, if partial, response. Reframing ecosystem functions as economic services does not address the political problem of commodification. Just as it obscures the labor of human workers, commodification obscures the importance of the biota (ecosystem workers) and related abiotic factors that contribute to ecosystem functions. This erasure of work done by ecosystems impedes public understanding of biodiversity. Odum and Odum's radical suggestion to use the language of ecosystems (i.e., emergy or energy memory) to describe economies, rather than using the language of economics (i.e., services) to describe ecosystems, reverses this erasure of the ecosystem worker. Considering the current dominance of economic forces, however, implementing such solutions would require social changes similar in magnitude to those that occurred during the 1960s. Niklas Luhmann argues that such substantive, yet rapid, social change requires synergy among multiple societal function systems (i.e., economy, education, law, politics, religion, science), rather than reliance on a single social sphere, such as the economy. Explicitly presenting ecosystem services as discreet and incomplete aspects of ecosystem functions not only allows potential economic and environmental benefits associated with ecosystem services, but also enables the social and political changes required to ensure valuation of ecosystem functions and related biodiversity in ways beyond their measurement on an economic scale. PMID:19659684

Peterson, Markus J; Hall, Damon M; Feldpausch-Parker, Andrea M; Peterson, Tarla Rai

2010-02-01

219

Natural Reserve System UNIVERSITY OF CALIFORNIA  

E-print Network

of ecosystems throughout California. Reserves offer outdoor laboratories to field scientists, classrooms without Eastern Sierra Reserves: 34 Sierra Nevada Aquatic Research Laboratory 35 Valentine Camp Santa Cruz 36 Año build nest mounds beneath oaks dripping with lic

California at Santa Cruz, University of

220

Navigating Fragmented Ocean Law in the California Current: Tools to Identify and Measure Gaps and Overlaps for Ecosystem-Based Management  

E-print Network

Mining of Ocean Law to Measure Overlapping Jurisdictions Digital Government Research, Montreal, Canada. mining of ocean law to measure overlapping agency and jurisdictional authority in Proceedings of the Digital Government Research Conference, Montreal, Canada.

Ekstrom, Julia A.

2008-01-01

221

Navigating Fragmented Ocean Law in the California Current: Tools to Identify and Measure Gaps and Overlaps for Ecosystem-Based Management  

E-print Network

quality, CO 2 , pH, and chemical water quality because theses (EPA) marine water quality criteria for human-induced pHwater quality standards, this is apparent from its high involvement in the Effect category which contained components of carbonate, pH,

Ekstrom, Julia A.

2008-01-01

222

Sea Surface Current Estimates off Central California as Derived from Enhanced AVHRR (Advanced Very High Resolution Radiometer) Infrared Images.  

National Technical Information Service (NTIS)

A technique is presented which uses an interactive computer program to estimate sea surface current velocities from the displacement of sea surface temperature (SST) patterns apparent in enhanced sequential infrared images obtained from the NOAA-6 Advance...

C. M. Fang

1987-01-01

223

Defining trade-offs among conservation, profitability, and food security in the California current bottom-trawl fishery.  

PubMed

Although it is recognized that marine wild-capture fisheries are an important source of food for much of the world, the cost of sustainable capture fisheries to species diversity is uncertain, and it is often questioned whether industrial fisheries can be managed sustainably. We evaluated the trade-off among sustainable food production, profitability, and conservation objectives in the groundfish bottom-trawl fishery off the U.S. West Coast, where depletion (i.e., reduction in abundance) of six rockfish species (Sebastes) is of particular concern. Trade-offs are inherent in this multispecies fishery because there is limited capacity to target species individually. From population models and catch of 34 stocks of bottom fish, we calculated the relation between harvest rate, long-term yield (i.e., total weight of fish caught), profit, and depletion of each species. In our models, annual ecosystem-wide yield from all 34 stocks was maximized with an overall 5.4% harvest rate, but profit was maximized at a 2.8% harvest rate. When we reduced harvest rates to the level (2.2% harvest rate) at which no stocks collapsed (<10% of unfished levels), biomass harvested was 76% of the maximum sustainable yield and profit 89% of maximum. A harvest rate under which no stocks fell below the biomass that produced maximum sustainable yield (1% harvest rate), resulted in 45% of potential yield and 67% of potential profit. Major reductions in catch in the late 1990s led to increase in the biomass of the most depleted stocks, but this rebuilding resulted in the loss of >30% of total sustainable yield, whereas yield lost from stock depletion was 3% of total sustainable yield. There are clear conservation benefits to lower harvest rates, but avoiding overfishing of all stocks in a multispecies fishery carries a substantial cost in terms of lost yield and profit. PMID:22443131

Hilborn, Ray; Stewart, Ian J; Branch, Trevor A; Jensen, Olaf P

2012-04-01

224

Arctic Ecosystems  

NSDL National Science Digital Library

Scientists predict that the climate in most parts of the world will warm dramatically in the next century, with change expected to occur earliest and be most pronounced in polar regions. In light of this, there is an urgent need to understand different aspects of the Earth's climate system, including the role that Arctic ecosystems play in regulating the Earth's climate and how food webs are affected by the changing climate. This module explores the Arctic Ocean ecosystem through interaction with a model that simulates how phytoplankton and zooplankton interact and respond to changes in season, sea ice, and nutrients.

Byrd, Greg

2010-01-01

225

An Overview of the Impacts of Pacific Decadal Climate Variability on Marine Ecosystems  

NASA Astrophysics Data System (ADS)

Over the past few decades a wealth of evidence has pointed to strong associations between multi-decadal climate changes and marine ecosystem changes in the Pacific. The period from the late 1970's through the mid-1990's, for example, saw sustained high productivity for most Pacific salmon at the northern end of their range coinciding with sustained low productivity for Pacific salmon at the southern end of their range. It is now recognized that this "north-south inverse production pattern" for Pacific salmon played out over much of the 20th Century in response to Pacific Decadal climate variations. There is abundant direct and indirect evidence for decadal scale climate impacts on many other Pacific marine species, including (among others) sardines and anchovies in the Humboldt and California Currents, and pollock and crab in the Bering Sea. In special cases, interdecadal ecosystem changes have been termed "ecosystem regime shifts", wherein evidence points to large-scale ecosystem restructuring at both lower and upper trophic levels. Understanding the mechanisms linking decadal variations in climate to ecosystems has proven to be a major challenge, and the lack of understanding poses a serious barrier to predicting ecosystem changes at the time-space scales important to resource managers and the fishing industry.

Mantua, N.

2006-12-01

226

A separating coastal upwelling jet at Cape Blanco, Oregon and its connection to the California Current System  

Microsoft Academic Search

The coastal upwelling region near Cape Blanco, Oregon (43N) off the west coast of the United States was studied using a towed CTD on SeaSoar, a shipboard acoustic Doppler current profiler (ADCP), satellite sea surface temperature maps and surface drifters during August 1995. The equatorward upwelling jet was inshore of the shelfbreak north of Cape Blanco, meandered gently offshore around

John A. Barth; Stephen D. Pierce; Robert L. Smith

2000-01-01

227

California State Waters Map Series: offshore of San Gregorio, California  

USGS Publications Warehouse

In 2007, the California Ocean Protection Council initiated the California Seafloor Mapping Program (CSMP), designed to create a comprehensive seafloor map of high-resolution bathymetry, marine benthic habitats, and geology within the 3-nautical-mile limit of California's State Waters. The CSMP approach is to create highly detailed seafloor maps through collection, integration, interpretation, and visualization of swath sonar data, acoustic backscatter, seafloor video, seafloor photography, high-resolution seismic-reflection profiles, and bottom-sediment sampling data. The map products display seafloor morphology and character, identify potential marine benthic habitats, and illustrate both the surficial seafloor geology and shallow (to about 100 m) subsurface geology. The Offshore of San Gregorio map area is located in northern California, on the Pacific coast of the San Francisco Peninsula about 50 kilometers south of the Golden Gate. The map area lies offshore of the Santa Cruz Mountains, part of the northwest-trending Coast Ranges that run roughly parallel to the San Andreas Fault Zone. The Santa Cruz Mountains lie between the San Andreas Fault Zone and the San Gregorio Fault system. The nearest significant onshore cultural centers in the map area are San Gregorio and Pescadero, both unincorporated communities with populations well under 1,000. Both communities are situated inland of state beaches that share their names. No harbor facilities are within the Offshore of San Gregorio map area. The hilly coastal area is virtually undeveloped grazing land for sheep and cattle. The coastal geomorphology is controlled by late Pleistocene and Holocene slip in the San Gregorio Fault system. A westward bend in the San Andreas Fault Zone, southeast of the map area, coupled with right-lateral movement along the San Gregorio Fault system have caused regional folding and uplift. The coastal area consists of high coastal bluffs and vertical sea cliffs. Coastal promontories in the northern and southern parts of the map area are the result of right-lateral motion on strands of the San Gregorio Fault system. In the south, headlands near Pescadero Point have been uplifted by motion along the west strand of the San Gregorio Fault (also called the Frijoles Fault), which separates rocks of the Pigeon Point Formation south of the fault from rocks of the Purisima Formation north of the fault. The regional uplift in this map area has caused relatively shallow water depths within California's State Waters and, thus, little accommodation space for sediment accumulation. Sediment is observed offshore in the central part of the map area, in the shelter of the headlands north of the east strand of the San Gregorio Fault (also called the Coastways Fault) around Miramontes Point (about 5 km north of the map area) and also on the outer half of the California's State Waters shelf in the south where depths exceed 40 m. Sediment in the outer shelf of California's State Waters is rippled, indicating some mobility. The Offshore of San Gregorio map area lies within the cold-temperate biogeographic zone that is called either the "Oregonian province" or the "northern California ecoregion." This biogeographic province is maintained by the long-term stability of the southward-flowing California Current, an eastern limb of the North Pacific subtropical gyre that flows from Oregon to Baja California. At its midpoint off central California, the California Current transports subarctic surface (0500 m deep) waters southward, about 150 to 1,300 km from shore. Seasonal northwesterly winds that are, in part, responsible for the California Current, generate coastal upwelling. The south end of the Oregonian province is at Point Conception (about 350 km south of the map area), although its associated phylogeographic group of marine fauna may extend beyond to the area offshore of Los Angeles in southern California. The ocean off of central California has experienced a warming over the last 50 years that is driving an ecosystem shift away from the productive subarctic r

Cochrane, Guy R.; Dartnell, Peter; Greene, H. Gary; Watt, Janet T.; Golden, Nadine E.; Endris, Charles A.; Phillips, Eleyne L.; Hartwell, Stephen R.; Johnson, Samuel Y.; Kvitek, Rikk G.; Erdey, Mercedes D.; Bretz, Carrie K.; Manson, Michael W.; Sliter, Ray W.; Ross, Stephanie L.; Dieter, Bryan E.; Chin, John L.; edited by Cochrane, Guy R.; Cochran, Susan A.

2014-01-01

228

Long-term, high-frequency current and temperature measurements along central California: Insights into upwelling/relaxation and internal waves on the inner shelf  

USGS Publications Warehouse

Thermistor chains and acoustic Doppler current profilers were deployed at the northern and southern ends of Monterey Bay to examine the thermal and hydrodynamic structure of the inner (h ??? 20 m) shelf of central California. These instruments sampled temperature and current velocity at 2-min intervals over a 13-month period from June 2000 to July 2001. Time series of these data, in conjunction with SST imagery and CODAR sea surface current maps, helped to establish the basic hydrography for Monterey Bay. Analysis of time series data revealed that depth integrated flow at both sites was shore parallel (northwest-southeast) with net flows out of the Bay (northwest). The current and temperature records were dominated by semi-diurnal and diurnal tidal signals that lagged the surface tides by 3 h on average. Over the course of an internal tidal cycle these flows were asymmetric, with the flow during the flooding internal tide to the southeast typically lasting only one-third as long as the flow to the northwest during the ebbing internal tide. The transitions from ebb to flood were rapid and bore-like in nature; they were also marked by rapid increases in temperature and high shear. During the spring and summer, when thermal stratification was high, we observed almost 2000 high-frequency (Tp ??? 4-20 min) internal waves in packets of 8-10 following the heads of these bore-like features. Previous studies along the West Coast of the US have concluded that warm water bores and high-frequency internal waves may play a significant role in the onshore transport of larvae.

Storlazzi, C. D.; McManus, M. A.; Figurski, J. D.

2003-01-01

229

-California -Washington  

E-print Network

Pacific - California - Oregon - Washington #12;Regional Summary Pacific Region Management Context The Pacific Region includes California, Oregon, and Washington. Federal fisheries in this region are managed

230

Digital Ecosystems: Ecosystem-Oriented Architectures  

Microsoft Academic Search

We view Digital Ecosystems to be the digital counterparts of biological ecosystems. Here, we are concerned with the creation\\u000a of these Digital Ecosystems, exploiting the self-organising properties of biological ecosystems to evolve high-level software\\u000a applications. Therefore, we created the Digital Ecosystem, a novel optimisation technique inspired by biological ecosystems,\\u000a where the optimisation works at two levels: a first optimisation, migration

Gerard Briscoe; Suzanne Sadedin; Philippe De Wilde

2011-01-01

231

Stable Isotope Analysis Challenges Wasp-Waist Food Web Assumptions in an Upwelling Pelagic Ecosystem  

PubMed Central

Eastern boundary currents are often described as wasp-waist ecosystems in which one or few mid-level forage species support a high diversity of larger predators that are highly susceptible to fluctuations in prey biomass. The assumption of wasp-waist control has not been empirically tested in all such ecosystems. This study used stable isotope analysis to test the hypothesis of wasp-waist control in the southern California Current large marine ecosystem (CCLME). We analyzed prey and predator tissue for ?13C and ?15N and used Bayesian mixing models to provide estimates of CCLME trophic dynamics from 20072010. Our results show high omnivory, planktivory by some predators, and a higher degree of trophic connectivity than that suggested by the wasp-waist model. Based on this study period, wasp-waist models oversimplify trophic dynamics within the CCLME and potentially other upwelling, pelagic ecosystems. Higher trophic connectivity in the CCLME likely increases ecosystem stability and resilience to perturbations. PMID:22977729

Madigan, Daniel J.; Carlisle, Aaron B.; Dewar, Heidi; Snodgrass, Owyn E.; Litvin, Steven Y.; Micheli, Fiorenza; Block, Barbara A.

2012-01-01

232

Marine Ecosystems  

NSDL National Science Digital Library

In the wild, small crustaceans known as brine shrimp live in marine habitats such as saltwater lakes. In this activity, learners create a saltwater or marine ecosystem that becomes an experimental brine shrimp hatchery. Learners observe the brine shrimp life cycle and test the effect of salinity (salt content) on brine shrimp eggs and larvae, as well as consider the potential impact of other variables such as water temperature and pollution.

Jersey, New; Center, Liberty S.; Coalition, New J.

2006-01-01

233

Annual Report to the Bonneville Power Administration, Reporting Period: April 2008 - February 2009 [re: "Survival and Growth in the Columbia River Plume and north California Current"].  

SciTech Connect

We have made substantial progress toward our objectives outlined in our BPA supported proposal entitled 'Columbia River Basin Juvenile Salmonids: Survival and Growth in the Columbia River Plume and northern California Current' which we report on herein. During 2008, we were able to successfully conduct 3 mesoscale cruises. We also were able to conduct 7 biweekly predator cruises, along with substantial shore-based visual observations of seabirds. Detailed results of the mesoscale cruises are available in the Cruise Reports and summarized in the next section. We have taken a proactive approach to getting the results of our research to fisheries managers and the general public. We have begun to make annual predictions based on ocean conditions of the relative survival of juvenile coho and Chinook salmon well before they return as adults. This is based on both biological and physical indicators that we measure during our surveys or collect from outside data sources. Examples of our predictions for 2009 and 2010 are available on the following web site: http://www.nwfsc.noaa.gov/research/divisions/fed/oeip/a-ecinhome.cfm.

Northwest Fisheries Science Center, NOAA Fisheries; Cooperative Institute for Marine Resources Studies, Oregon State University; OGI School of Science & Engineering, Oregon Health Sciences University.

2009-07-17

234

STATE OF CALIFORNIA --NATURAL RESOURCES AGENCY EDMUND G. BROWN JR., Governor CALIFORNIA ENERGY COMMISSION  

E-print Network

STATE OF CALIFORNIA -- NATURAL RESOURCES AGENCY EDMUND G. BROWN JR., Governor CALIFORNIA ENERGY current and future energy storage can provide benefits to California; 6) discuss how and what needs COMMISSION 1516 Ninth Street Sacramento, California 95814 Main website: www.energy.ca.gov In the matter of

235

STATE OF CALIFORNIA --NATURAL RESOURCES AGENCY EDMUND G BROWN, JR., Governor CALIFORNIA ENERGY COMMISSION  

E-print Network

STATE OF CALIFORNIA -- NATURAL RESOURCES AGENCY EDMUND G BROWN, JR., Governor CALIFORNIA ENERGY $36.7 billion to energy-related projects nationwide with California currently awarded approximately $5 COMMISSION 1516 Ninth Street Sacramento, California 95814 Main website: www.energy.ca.gov Notice

236

Quantifying water flow within aquatic ecosystems using load cell sensors: a profile of currents experienced by coral reef organisms around Lizard Island, Great Barrier Reef, Australia.  

PubMed

Current velocity in aquatic environments has major implications for the diversity, abundance and ecology of aquatic organisms, but quantifying these currents has proven difficult. This study utilises a simple and inexpensive instrument (<$150) to provide a detailed current velocity profile of the coral-reef system around Lizard Island (Great Barrier Reef, Australia) at a spatial and temporal scale relevant to the ecology of individual benthos and fish. The instrument uses load-cell sensors to provide a correlation between sensor output and ambient current velocity of 99%. Each instrument is able to continuously record current velocities to >500 cms? and wave frequency to >100 Hz over several weeks. Sensor data are registered and processed at 16 MHz and 10 bit resolution, with a measuring precision of 0.060.04%, and accuracy of 0.510.65% (mean S.D.). Each instrument is also pressure rated to 120 m and shear stresses ?20 kNm? allowing deployment in harsh environments. The instrument was deployed across 27 coral reef sites covering the crest (3 m), mid-slope (6 m) and deep-slope (9 m depth) of habitats directly exposed, oblique or sheltered from prevailing winds. Measurements demonstrate that currents over the reef slope and crest varies immensely depending on depth and exposure: currents differ up to 9-fold within habitats only separated by 3 m depth and 15-fold between exposed, oblique and sheltered habitats. Comparisons to ambient weather conditions reveal that currents around Lizard Island are largely wind driven. Zero to 22.5 knot winds correspond directly to currents of 0 to >82 cms?, while tidal currents rarely exceed 5.5 cms?. Rather, current velocity increases exponentially as a function of wave height (0 to 1.6 m) and frequency (0.54 to 0.20 Hz), emphasizing the enormous effect of wind and waves on organisms in these shallow coral reef habitats. PMID:24421878

Johansen, Jacob L

2014-01-01

237

Quantifying Water Flow within Aquatic Ecosystems Using Load Cell Sensors: A Profile of Currents Experienced by Coral Reef Organisms around Lizard Island, Great Barrier Reef, Australia  

PubMed Central

Current velocity in aquatic environments has major implications for the diversity, abundance and ecology of aquatic organisms, but quantifying these currents has proven difficult. This study utilises a simple and inexpensive instrument (<$150) to provide a detailed current velocity profile of the coral-reef system around Lizard Island (Great Barrier Reef, Australia) at a spatial and temporal scale relevant to the ecology of individual benthos and fish. The instrument uses load-cell sensors to provide a correlation between sensor output and ambient current velocity of 99%. Each instrument is able to continuously record current velocities to >500 cms?1 and wave frequency to >100 Hz over several weeks. Sensor data are registered and processed at 16 MHz and 10 bit resolution, with a measuring precision of 0.060.04%, and accuracy of 0.510.65% (mean S.D.). Each instrument is also pressure rated to 120 m and shear stresses ?20 kNm?2 allowing deployment in harsh environments. The instrument was deployed across 27 coral reef sites covering the crest (3 m), mid-slope (6 m) and deep-slope (9 m depth) of habitats directly exposed, oblique or sheltered from prevailing winds. Measurements demonstrate that currents over the reef slope and crest varies immensely depending on depth and exposure: Currents differ up to 9-fold within habitats only separated by 3 m depth and 15-fold between exposed, oblique and sheltered habitats. Comparisons to ambient weather conditions reveal that currents around Lizard Island are largely wind driven. Zero to 22.5 knot winds correspond directly to currents of 0 to >82 cms?1, while tidal currents rarely exceed 5.5 cms?1. Rather, current velocity increases exponentially as a function of wave height (0 to 1.6 m) and frequency (0.54 to 0.20 Hz), emphasizing the enormous effect of wind and waves on organisms in these shallow coral reef habitats. PMID:24421878

Johansen, Jacob L.

2014-01-01

238

You Can Tailor Effluent BOD to Fit the Receiving-Water Ecosystem...and Enhance the Environment. Urban and Fish-Processing Wastes in the Marine Environment: Bioenhancement Studies at Terminal Island, California.  

National Technical Information Service (NTIS)

Coastal marine waters, among the richest ecosystems in existence, are largely dependent upon nutrients of terrestrial origin. Where man has reduced or eliminated marshlands and river flow, urban sewage systems offer virtually the only nutrient source for ...

D. F. Soule, M. Oguri, J. D. Soule

1978-01-01

239

Impacts of mountain pine beetle outbreak on biogeochemical cycling in a high elevation whitebark pine ecosystem.  

E-print Network

??Ecological disturbances can significantly impact biogeochemical cycles in terrestrial ecosystems, but the effects of the current widespread mountain pine beetle outbreak on ecosystem processes like (more)

Keville, Megan

2012-01-01

240

History and Development of Kindergarten in California.  

National Technical Information Service (NTIS)

This report reviews the history of kindergarten in California. It is an interesting story in its own right, one in which several women in California pioneered the kindergarten concept and contributed to a nationwide movement. The report puts current polic...

P. L. de Cos

2001-01-01

241

Comparison of risk from pyroclastic density current hazards to critical infrastructure in Mammoth Lakes, California, USA, from a new Inyo craters rhyolite dike eruption versus a dacitic dome eruption on Mammoth Mountain  

Microsoft Academic Search

Renewed volcanic activity near Mammoth Lakes, California, in the form of dome-collapse pyroclastic density currents (PDCs)\\u000a from either a new eruption at Mammoth Mountain or the Inyo craters would pose a significant hazard to critical infrastructure\\u000a there. This paper compares the risk from PDC impact hazards upon selected critical infrastructure from: (1) a 100m tall dacite\\u000a dome on Mammoth Mountain

Grant Kaye; Jim Cole; Andrew King; David Johnston

2009-01-01

242

CALIFORNIA COMMISSION  

E-print Network

, and prices." The Energy Commission uses these assessments and forecasts to develop energy policies CALIFORNIA ENERGY COMMISSION SCENARIO-BASED ASSESSMENT OF RESOURCE PLANS PREDICATED Integrated Energy Policy Report #12;CALIFORNIA ENERGY COMMISSION Michael R. Jaske Principal Author Global

243

Terrestrial Ecosystem Adaptation  

E-print Network

Terrestrial Ecosystem Adaptation Steven W. Running and L. Scott Mills RFF REPORT ............................... 16 Expected Future Ecosystem Trends ................................................................................................................................................................ 27 #12; RUNNING AND MILLS 1 Terrestrial Ecosystem Adaptation Steven W. Running and L. Scott

Mills, L. Scott

244

Fishing for Novel Approaches to Ecosystem Service Forecasts  

EPA Science Inventory

The ecosystem service concept provides a powerful framework for conserving species and the environments they depend upon. Describing current distributions of ecosystem services and forecasting their future distributions have therefore become central objectives in many conservati...

245

A perspective on modern pesticides, pelagic fish declines, and unknown ecological resilience in highly managed ecosystems  

USGS Publications Warehouse

Pesticides applied on land are commonly transported by runoff or spray drift to aquatic ecosystems, where they are potentially toxic to fishes and other nontarget organisms. Pesticides add to and interact with other stressors of ecosystem processes, including surface-water diversions, losses of spawning and rearing habitats, nonnative species, and harmful algal blooms. Assessing the cumulative effects of pesticides on species or ecological functions has been difficult for historical, legal, conceptual, and practical reasons. To explore these challenges, we examine current-use (modern) pesticides and their potential connections to the abundances of fishes in the San Francisco Estuary (California). Declines in delta smelt (Hypomesus transpacificus), Chinook salmon (Oncorhynchus tshawytscha), and other species have triggered mandatory and expensive management actions in the urbanizing estuary and agriculturally productive Central Valley. Our inferences are transferable to other situations in which toxics may drive changes in ecological status and trends.

Scholz, Nathaniel L.; Fleishman, Erica; Brown, Larry; Werner, Inge; Johnson, Michael L.; Brooks, Marjorie L.; Mitchelmore, Carys L.; Schlenk, Daniel

2012-01-01

246

Anchovy (Engraulis ringens) and sardine (Sardinops sagax) spatial dynamics and aggregation patterns in the Humboldt Current ecosystem, Peru, from 1983?2003  

Microsoft Academic Search

Three indexes of spatial aggregation are developed and used to examine the aggregation pattern of sardine (Sardinops sagax) and anchovy (Engraulis ringens )i n the Peruvian Humboldt Current System, determined from 36 acoustic surveys conducted from 1983 through 2003 by the Peruvian Marine Institute (IMARPE). Each index assesses a different aspect of aggregation: the concentration, the percent occupancy of space

MARIANO GUTIRREZ; GORDON SWARTZMAN; ARNAUD BERTRAND; SOPHIE BERTRAND

2007-01-01

247

Astronomical Ecosystems  

NASA Astrophysics Data System (ADS)

Just as quetzals and jaguars require specific ecological habitats to survive, so too must planets occupy a tightly constrained astronomical habitat to support life as we know it. With this theme in mind we relate the transferable features of our elementary astronomy course, "The Astronomical Basis of Life on Earth." Over the last five years, in a team-taught course that features a spring break field trip to Costa Rica, we have introduced astronomy through "astronomical ecosystems," emphasizing astronomical constraints on the prospects for life on Earth. Life requires energy, chemical elements, and long timescales, and we emphasize how cosmological, astrophysical, and geological realities, through stabilities and catastrophes, create and eliminate niches for biological life. The linkage between astronomy and biology gets immediate and personal: for example, studies in solar energy production are followed by hikes in the forest to examine the light-gathering strategies of photosynthetic organisms; a lesson on tides is conducted while standing up to our necks in one on a Pacific beach. Further linkages between astronomy and the human timescale concerns of biological diversity, cultural diversity, and environmental sustainability are natural and direct. Our experience of teaching "astronomy as habitat" strongly influences our "Astronomy 101" course in Oklahoma as well. This "inverted astrobiology" seems to transform our student's outlook, from the universe being something "out there" into something "we're in!" We thank the SNU Science Alumni support group "The Catalysts," and the SNU Quetzal Education and Research Center, San Gerardo de Dota, Costa Rica, for their support.

Neuenschwander, D. E.; Finkenbinder, L. R.

2004-05-01

248

ECOSYSTEM ECOLOGY -ORIGINAL PAPER Increasing donor ecosystem productivity decreases terrestrial  

E-print Network

ECOSYSTEM ECOLOGY - ORIGINAL PAPER Increasing donor ecosystem productivity decreases terrestrial Abstract Because nutrient enrichment can increase ecosystem productivity, it may enhance resource flows to adjacent ecosystems as organisms cross ecosystem bound- aries and subsidize predators in recipient

Rosemond, Amy Daum

249

CALIFORNIA ENERGY CALIFORNIA'S STATE ENERGY  

E-print Network

CALIFORNIA ENERGY COMMISSION CALIFORNIA'S STATE ENERGY EFFICIENT APPLIANCE REBATE PROGRAM INITIAL November 2009 CEC-400-2009-026-CMD Arnold Schwarzenegger, Governor #12;#12;CALIFORNIA ENERGY COMMISSION Program Manager Paula David Supervisor Appliance and Process Energy Office Valerie T. Hall Deputy Director

250

Valuation of rangeland ecosystem services  

USGS Publications Warehouse

Economic valuation lends itself well to the anthropocentric orientation of ecosystem services. An economic perspective on ecosystems portrays them as natural assets providing a flow of goods and services valuable to individuals and society collectively. A few examples include the purification of drinking water, reduced risk from flooding and other extreme events, pollination of agricultural crops, climate regulation, and recreation opportunities from plant and animal habitat maintenance, among many others. Once these goods and services are identified and quantified, they can be monetized to complete the valuation process. The monetization of ecosystem goods and services (in the form of dollars) provides a common metric that allows for cross-comparison of attributes and evaluation of differing ecological scenarios. Complicating the monetization process is the fact that most of these goods and services are public and non-market in nature; meaning they are non-rival and non-exclusive and are typically not sold in a traditional market setting where monetary values are revealed. Instead, one must employ non-market valuation techniques, with primary valuation methods typically being very time and resource consuming, intimidating to non-economists, and often impractical. For these reasons, benefit transfer methods have gained popularity. This methodology harnesses the primary collection results of existing studies to make inferences about the economic values of non-market goods and services at an alternative policy site (in place and/or in time). For instance, if a primary valuation study on oak reestablishment on rangelands in southern California yielded a value of $30 per-acre associated with water regulation, this result can be transferred, with some adjustments, to say something about the value of an acre of oaks on rangelands in northern portions of the state. The economic valuation of rangeland ecosystem services has many roles. Economic values may be used as input into analyzing the costs and benefits associated with policies being proposed, or possibly already implemented. For example, with monetized values acting as a common metric, one could compare the 'benefits' of converting a rangeland ecosystem for commercial development (perhaps estimated at the market value of the developed land) with the foregone ecosystem service values (in addition to any land income lost) resulting from that land conversion. Similarly, ecosystem service values can be used to determine the level of return on an investment. rhis is a primary objective for private land conservation organizations who typically have very limited resources. Ecosystem service valuation can also have a role in damage assessments from incidents that require compensation such as oil spills. Additionally, valuation can be very informative when investigating regulatory programs that trade ecological assets such as wetland mitigation programs. Typically these programs are based simply on an 'acre for acre' criterion, and do not take into consideration varying welfare values associated with that ecosystem. Lastly, and most fundamental, ecosystem service valuation serves as a recognition tool for people of all backgrounds. Identifying and valuing ecosystem goods and services on rangelands brings to light the value these natural assets have to human welfare that often remain hidden do to their public and non-market attributes. This type of recognition is vital to the preservation of rangeland ecosystems in the future and the many ecological benefits they provide.

Gascoigne, W. R.

2011-01-01

251

Ecosystem element cycling Introduction  

E-print Network

Ecosystem element cycling Introduction An ecosystem consists of all the biological organisms and the physical environments they occupy together within a defined area [1]. The actual boundaries of an ecosystem are generally defined by researchers studying the ecosystem, who are usually interested in understanding

Ickert-Bond, Steffi

252

Internet Geography: Ecosystems  

NSDL National Science Digital Library

This site about ecosystems and biomes contains a map of different ecosystems, and provides rainfall statistics for each biome. There are sections on tropical rainforest, taiga (or boreal forest), savanna, desert, and tundra ecosystems. Each section describes the biome and its origins, where it is found, and how humans impact it. In some cases, sustainable development of the ecosystem is explained.

253

RESEARCH TOPICS: Tree Guidelines for California Communities, Benefit-Cost Analyses, Energy and Carbon Dioxide Reduction through Urban Forestry, Air Quality and Parking Lot Shade, Urban Watershed Protection, Urban Forest Inventory and Monitoring, Green Infrastructure, Sustainable Urban Ecosystems  

Microsoft Academic Search

In California, repairing sidewalk damage associated with tree roots exceeds $62 million annuall this study, three types of root barriers were installed and evaluated to determine whether 1) inte (12 in.) of soil. The three barriers tested included 1) a modified production container, partially le intended to prevent circling roots and 3) a commercial product with vertical ribs spaced 12.5

Root Barrier; Extension Pau

254

STATE OF CALIFORNIA RESIDENTIAL LIGHTING  

E-print Network

), dimmers, track lighting integral current limiters, and outdoor motion sensors. 4. Lighting ControlsSTATE OF CALIFORNIA RESIDENTIAL LIGHTING CEC-CF-6R-LTG-01 (Revised 08/09) CALIFORNIA ENERGY COMMISSION INSTALLATION CERTIFICATE CF-6R-LTG-01 Residential Lighting (Page 1 of 6) Site Address: Enforcement

255

California Energy Commission STAFF REPORT  

E-print Network

;#12;i ABSTRACT California has a long history of developing renewable energy resources to help meet its by renewable developers who use those lands. The report outlines the current amount of renewable energyCalifornia Energy Commission STAFF REPORT DEVELOPING RENEWABLE GENERATION ON STATE PROPERTY

256

The State of Ecosystems  

NSDL National Science Digital Library

The recent Millennium Ecosystem Assessment has illustrated that human actions have significantly transformed many of Earths ecosystems. The main findings describe how: humans changed ecosystems dramatically over the past 50 years, changes to ecosystem services may get worse in the next 50 years, global action at all levels can reverse the degradation, and how ecosystem degradation increases risks of sudden changes and reduces benefits for future generations.

Christi¡n Samper (National Museum of Natural History of the Smithsonian Institution;)

2005-08-01

257

The Carbon Budget of California  

NASA Astrophysics Data System (ADS)

The carbon budget of a region can be defined as the sum of annual fluxes of carbon dioxide and methane greenhouse gases (GHGs) into and out of the regional surface coverage area. According to the state governments recent inventory, California's carbon budget is presently dominated by fossil fuel emissions of CO2 (at >85% of total annual GHG emissions) to meet energy and transportation requirements. Other notable (non-ecosystem) sources of carbon GHG emissions in 2004 were from cement- and lime-making industries, livestock-based agriculture, and waste treatment activities. The NASA-CASA (Carnegie Ames Stanford Approach) simulation model based on satellite observations of monthly vegetation cover (including those from the Moderate Resolution Imaging Spectroradiometer - MODIS) has been used to estimate net ecosystem fluxes and vegetation biomass production over the period 1990-2004. California's annual NPP for all ecosystems in the early 2000s, estimated by CASA at 120 million metric tons of carbon equivalent (MMTCE) per year, was roughly equal to its annual fossil fuel emission rates for carbon. However, since natural ecosystems can accumulate only a small fraction of this annual NPP total in long-term storage pools, the net ecosystem sink flux for atmospheric carbon across the state was estimated at a maximum rate of between 15-24 MMTCE per year under favorable precipitation conditions. Under less favorable precipitation conditions, such as those experienced during the early 1990s, ecosystems statewide were estimated to have lost nearly 15 MMTCE per year to the atmosphere. Considering the large amounts of carbon stored in standing biomass of forests, shrublands, and rangelands across the state, the implications of changing climate and land use practices on ecosystems must be factored into the states planning to reduce overall GHG emissions.

Potter, C. S.

2009-12-01

258

Pelagic amphipod assemblage associated with subarctic water off the West Coast of the Baja California peninsula  

NASA Astrophysics Data System (ADS)

The California Current system is a large marine ecosystem with transition gradients between subarctic and tropical biomes containing diverse habitats. Biogeographic species groups must be carefully analyzed in order to detect tendencies shifting the ecosystem toward a more temperate or tropical state. Species composition of hyperiid amphipods was analyzed in July 2002 for evidence of subarctic water intrusion and for signals of the El Nio event developing in the equatorial Pacific. Multivariate analysis showed a dominance of transition zone species typical of the California Current. The main evidence of subarctic water intrusion was the extended distribution of Themisto pacifica, which reached as far south as 27N, with particularly high abundances at 30-32N. The intrusion of subarctic water took place despite evidence that an El Nio event was in progress. The zonal advection due to El Nio intersected the equatorward flow of the subarctic intrusion and probably produced a large cyclonic eddy off Baja California. This eddy maintained a limited El Nio influence at a few offshore stations near its southern boundary. The main environmental variables influencing the amphipod assemblage structure were water temperature and the abundance of salps. T. pacifica, a species with cool water affinity, was more sensitive to temperature, whereas subtropical species, such as Vibilia armata, were strongly correlated with the availability of salps.

Lavaniegos, Bertha E.

2014-04-01

259

Review of current Southern California edison load management programs and proposal for a new market-driven, mass-market, demand-response program  

SciTech Connect

Utility load management programs, including direct load control and interruptible load programs, constitute a large installed base of controllable loads that are employed by utilities as system reliability resources. In response to energy supply shortfalls expected during the summer of 2001, the California Public Utilities Commission in spring 2001 authorized new utility load management programs as well as revisions to existing programs. This report provides an independent review of the designs of these new programs for a large utility (Southern California Edison) and suggests possible improvements to enhance the price responsiveness of the customer actions influenced by these programs. The report also proposes a new program to elicit a mass-market demand response to utility price signals.

Weller, G.H.

2002-01-01

260

CALIFORNIA COMMISSION  

E-print Network

Environmental Data Collection.......................................................................23 CHAPTER 3: Cooling Water Use at New Power Plants Subject to Energy Commission Jurisdiction ...........................................................................................25 How California Uses Water

261

Direct correlation of millennial-scale changes in western North American vegetation and climate with changes in the California Current system over the past ~60 kyr  

Microsoft Academic Search

Terrestrial (pollen) and marine climate proxies from seven sediment cores taken on the continental margin of western North America between 32 and 43N show systematically related short-term changes superposed on Milankovitch-scale oscillations of the past 60 kyr. During oxygen isotope stage 3, brief warming events in California and Oregon appear correlative with interstadial events in waters offshore, as do the

Linda Heusser

1998-01-01

262

Measuring the contribution of benthic ecosystem engineering species to the ecosystem services of an estuary: A case study of burrowing shrimps in Yaquina Estuary, Oregon  

EPA Science Inventory

Burrowing shrimps are regarded as ecosystem engineering species in many coastal ecosystems worldwide, including numerous estuaries of the west coast of North America (Baja California to British Columbia). In estuaries of the U.S. Pacific Northwest, two species of large burrowing...

263

Measuring the contribution of benthic ecosystem engineering species to the ecosystem services of an estuary: A case study of burrowing shrimps in Yaquina Estuary, Oregon - April 2009  

EPA Science Inventory

Burrowing shrimps are regarded as ecosystem engineering species in many coastal ecosystems worldwide, including numerous estuaries of the west coast of North America (Baja California to British Columbia). In estuaries of the U.S. Pacific Northwest, two species of large burrowing...

264

Pacific Island Ecosystems Research Center  

NSDL National Science Digital Library

The Pacific Island Ecosystems Research Center (PIERC) is part of the Biological Division of the United States Geological Survey (USGS). The mission of PIERC is to provide the scientific understanding and technologies needed to support the sound management and conservation of our Nation's biological resources occurring within the cultural, sociological, and political contexts of the State of Hawaii. The geographical isolation of the Hawaiian Islands has resulted in the evolution of a highly endemic biota, while human colonization has severely impacted native plant and animal populations. The PIERC website provides information and research studies about the Hawaiian Islands ecosystem, as well as staff projects that are currently in progress. Topics include birds, mammals, ecosystem diversity, genetics, wildlife health, plant ecology, and marine biology. There is an education section with outdoor activities, online activities, and a coloring book. Links are provided for further information.

265

Mobile Link Organisms and Ecosystem Functioning: Implications for Ecosystem Resilience and Management  

Microsoft Academic Search

Current natural resource management seldom takes the ecosystem functions performed by organisms that move between systems\\u000a into consideration. Organisms that actively move in the landscape and connect habitats in space and time are here termed mobile\\u000a links. They are essential components in the dynamics of ecosystem development and ecosystem resilience (that is, buffer capacity\\u000a and opportunity for reorganization) that provide

Jakob Lundberg; Fredrik Moberg

2003-01-01

266

Ecotoxicology of tropical marine ecosystems  

SciTech Connect

The negative effects of chemical contaminants on tropical marine ecosystems are of increasing concern as human populations expand adjacent to these communities. Watershed streams and ground water carry a variety of chemicals from agricultural, industrial, and domestic activities, while winds and currents transport pollutants from atmospheric and oceanic sources to these coastal ecosystems. The implications of the limited information available on impacts of chemical stressors on mangrove forests, seagrass meadows, and coral reefs are discussed in the context of ecosystem management and ecological risk assessment. Three classes of pollutants have received attention: heavy metals, petroleum, and synthetic organics. Heavy metals have been detected in all three ecosystems, causing physiological stress, reduced reproductive success, and outright mortality in associated invertebrates and fishes. Oil spills have been responsible for the destruction of entire coastal shallow-water communities, with recovery requiring years. Herbicides are particularly detrimental to mangroves and seagrasses and adversely affect the animal-algal symbioses in corals. Pesticides interfere with chemical cues responsible for key biological processes, including reproduction and recruitment of a variety of organisms. Information is lacking with regard to long-term recovery, indicator species, and biomarkers for tropical communities. Critical areas that are beginning to be addressed include the development of appropriate benchmarks for risk assessment, baseline monitoring criteria, and effective management strategies to protect tropical marine ecosystems in the face of mounting anthropogenic disturbance.

Peters, E.C. [Tetra Tech, Inc., Fairfax, VA (United States); Gassman, N.J.; Firman, J.C. [Univ. of Miami, FL (United States). Rosenstiel School of Marine and Atmospheric Science; Richmond, R.H. [Univ. of Guam, Mangilao (Guam). Marine Lab.; Power, E.A. [EVS Environment Consultants, Ltd., North Vancouver, British Columbia (Canada)

1997-01-01

267

167 Prospectus California Margin  

E-print Network

. Each of the three transects across the California Current will compare deep-water sites near the core), for those sites that require it, can be obtained from the following World Wide Web site: http margin, Deep Sea Drilling Project (DSDP) Leg 63, occurred immediately before the first deployment

268

MOBILE PROXIMITY PAYMENT: ECOSYSTEM  

E-print Network

MOBILE PROXIMITY PAYMENT: ECOSYSTEM AND OVERVIEW OF NFC TECHNOLOGY 1. Introduction Handsets confirm and heterogeneous. The Mobile Payment ecosystem involves a number of partners, such as: · banks; · Mobile Network

Shamos, Michael I.

269

San Jos State University San Jos, California  

E-print Network

-technology research and development center. Many of California's most popular national, recreational, and cultural) Applied/cultural anthropologist able to use anthropology to address "real-world" problems in and between and topical interests include technology and material culture, ecosystems and environmental change, mobility

Su, Xiao

270

Denitrification in coastal ecosystems: methods, environmental controls, and ecosystem level controls, a review  

Microsoft Academic Search

In this review of sediment denitrification in estuaries and coastal ecosystems, we examine current denitrification measurement methodologies and the dominant biogeochemical controls on denitrification rates in coastal sediments. Integrated estimates of denitrification in coastal ecosystems are confounded by methodological difficulties, a lack of systematic understanding of the effects of changing environmental conditions, and inadequate attention to spatial and temporal variability

Jeffrey C. Cornwell; W. Michael Kemp; Todd M. Kana

1999-01-01

271

Denitrification in coastal ecosystems: methods, environmental controls, and ecosystem level controls, a review  

Microsoft Academic Search

In this review of sediment denitrification in estuaries and coastal ecosystems, we examine current denitrification measurement methodologies and the dominant biogeochemical controls on denitrification rates in coastal sedi- ments. Integrated estimates of denitrification in coastal ecosystems are confounded by methodological difficulties, a lack of systematic understanding of the effects of changing environmental conditions, and inadequate attention to spatial and temporal

Jeffrey C. Cornwell; W. Michael Kemp; Todd M. Kana

1999-01-01

272

Ecosystem Health: Energy Indicators.  

EPA Science Inventory

Just as for human beings health is a concept that applies to the condition of the whole organism, the health of an ecosystem refers to the condition of the ecosystem as a whole. For this reason, the study and characterization of ecosystems is fundamental to establishing accurate ...

273

The polluted ecosystem game  

Microsoft Academic Search

Purpose The purpose of this paper is to address the issue of optimal management of ecosystems by developing a dynamic model of strategic behavior by users\\/communities of an ecosystem such as a lake, which is subject to pollution resulting from the users. More specifically, it builds a model of two ecosystems that are spatially connected. Design\\/methodology\\/approach The paper

W. A. Brock; W. D. Dechert

2008-01-01

274

I Spy an Ecosystem  

NSDL National Science Digital Library

We hear the word ecosystems in the news and at school but just what are ecosystems? It turns out there are lots of ecosystems. You might even learn you have some inside you! Also in: Français | Español

Biology

2009-09-22

275

The Ecosystem Science Center  

E-print Network

The Ecosystem Science Center 2010-2011 Annual report Photo, by graduate student Alex of the Ecosystem Science Center for the period July 1, 2010 July 1, 2011 Introduction to ESC ­ A Message from .......................................... 40 1 #12;A Message from the ESC Director The Ecosystem Science Center has now completed its

276

The Ecosystem Science Center  

E-print Network

1 The Ecosystem Science Center 2011-2012 Annual report #12;2 Table of Contents This document summarizes the activities of the Ecosystem Science Center for the period from July 1, 2011 July 1, 2012 of the Ecosystem Science Center who supported this research project in Calumet watershed with a graduate research

277

Emergy and ecosystem complexity  

Microsoft Academic Search

The question What drives complexity? is addressed in this paper. To answer this question, we explore the way energy and material resources of different quality flow through ecosystems and support, directly and indirectly, ecosystems growth and development. Processes of resource transformation throughout the ecosystem build order, cycle materials, generate and sustain information. Energy drives all these processes and energetic principles

Sergio Ulgiati; Mark T. Brown

2009-01-01

278

California's Accountability System and the API. Expert Report. Submitted for: Eliezer Williams vs. State of California.  

ERIC Educational Resources Information Center

This paper was presented as expert testimony in the Williams vs. State of California class action lawsuit. That case, filed on behalf of California public schoolchildren, charged the State with denying thousands of students the basic tools for a sound education. This paper addresses whether California's current output-based accountability system

Russell, Michael

279

STATE OF CALIFORNIA --NATURAL RESOURCES AGENCY EDMUND G. BROWN JR., Governor CALIFORNIA ENERGY COMMISSION  

E-print Network

STATE OF CALIFORNIA -- NATURAL RESOURCES AGENCY EDMUND G. BROWN JR., Governor CALIFORNIA ENERGY Resources Trust Fund by the end of the current fiscal year. The Governor's 2012-2013 Budget proposes a loan COMMISSION 1516 Ninth Street Sacramento, California 95814 Main website: www.energy.ca.gov Status of Funds

280

STATE OF CALIFORNIA --NATURAL RESOURCES AGENCY EDMUND G. BROWN JR., Governor CALIFORNIA ENERGY COMMISSION  

E-print Network

stations to serve the current population of fuel cell vehicles (FCVs) and to accommodate the planned large1 STATE OF CALIFORNIA -- NATURAL RESOURCES AGENCY EDMUND G. BROWN JR., Governor CALIFORNIA ENERGY COMMISSION 1516 Ninth Street Sacramento, California 95814 Main website: www.energy.ca.gov Hydrogen Fuel

281

Effects of ozone, nitrogen deposition, and other stressors on montane ecosystems in the Sierra Nevada  

Microsoft Academic Search

The greatest air pollution impacts in forests of California are the physiological disturbances imposed on trees as a result of the combined effects of excess N and phytotoxic ozone exposure (Takemoto etal., 2001). In highly-polluted stands in the San Bernardino Mountains in southern California, fine root biomass is greatly reduced and C cycling within the tree and within the ecosystem

Brent K Takemoto

2003-01-01

282

Native and Introduced Ecosystem Engineers Produce Contrasting Effects on Estuarine Infaunal Communities  

Microsoft Academic Search

Cordgrasses in the genus Spartina are good examples of ecosystem engineers that modify habitat structure in estuaries throughout the world. In San Francisco\\u000a Bay, California, USA, marshes containing native California cordgrass (Spartina foliosa) are being invaded by a hybrid (S. alterniflora S. foliosa) formed after introduction of S. alterniflora. This study compared vegetation, sediment structure, and infaunal invertebrates in

Elizabeth D. Brusati; Edwin D. Grosholz

2006-01-01

283

Agriculture, Ecosystems and Environment 87 (2001) 93109 Comparing pocket gopher (Thomomys bottae) density  

E-print Network

Agriculture, Ecosystems and Environment 87 (2001) 93­109 Comparing pocket gopher (Thomomys bottae.S. Smallwood et al. / Agriculture, Ecosystems and Environment 87 (2001) 93­109 (Plegadis chihi), prairie falcon by giant garter snake (Thamnophis gigas), California tiger salaman- der (Ambystoma californiense), western

Zhang, Minghua

284

Design of an Atmospheric Observing Strategy for California's Carbon Cycle  

NASA Astrophysics Data System (ADS)

We report the design of an atmospheric observing strategy to enable inverse estimation and attribution of CO2 (and other green house gases) exchange between the land surface and the atmosphere in California. Using models of the natural carbon cycle, fossil fuel emissions, and regional meteorology, we predict CO2 concentration "signals" that would be measured with current and proposed observing platforms. The CO2 sources can be broadly categorized as (1) strong and fairly constant positive fluxes from metropolitan areas (e.g., Los Angeles and San Francisco), (2) weaker but widely distributed positive and negative fluxes from diurnally and seasonally varying ecosystem exchange, and (3) weak but broadly distributed fossil emissions from the Central Valley. Maps of predicted CO2 signals for tower-based stations largely mirror the flux maps over land, while aircraft and column integrated signals (as would be observed with sounding instruments) reflect time-averaged fluxes from much larger areas. Predicted concentration signals away from urban areas are dependent on season, due primarily to variations in the natural carbon cycle, and secondarily to variations in fossil emissions and meteorology. Of significance for determining inflow boundary conditions, large plumes of CO2 enriched and depleted air (1-5 ppm) are predicted to advect from the Northwest to positions more than 300 km west of the California coast. This suggests that data from ocean-based stations must be incorporated into inversions using explicit estimations of regional terrestrial influence. We will also discuss ongoing work to: 1) identify a set of candidate observation stations for California, 2) estimate the influence of specific land surface elements to the measured signals, 3) predict atmospheric signals obtained from proposed strategies to increase ecosystem carbon sequestration.

Tonse, S. R.; Fischer, M. L.; Riley, W. J.

2004-12-01

285

The Greater Yellowstone Ecosystem: Challenges for Regional Ecosystem Management  

Microsoft Academic Search

An adaptive management approach is necessary but not sufficient to address the long-term challenges of the Greater Yellowstone\\u000a Ecosystem (GYE). Adaptive management, in turn, has its own particular challenges, of which we focus on two: science input, and stakeholder engagement. In order to frame our discussion and subsequent recommendations, we place the current management difficulties into their\\u000a historical context, with

Heather J. Lynch; Stephanie Hodge; Christian Albert; Molly Dunham

2008-01-01

286

Producer Nutritional Quality Controls Ecosystem Trophic Just Cebrian1.  

E-print Network

explain why ecosystems composed of highly nutritional primary producers feature high consumer productivity , William F. Fagan6 1 Dauphin Island Sea Lab and Department of Marine Sciences, University of South Alabama of America, 4 Department of Ecology, Evolution and Marine Biology, University of California Santa Barbara

Cardinale, Bradley J.

287

PHOTOCHEMICAL AIR POLLUTANT EFFECTS ON MIXED CONIFER ECOSYSTEMS  

EPA Science Inventory

In 1972, a multi-disciplinary team of ecologists assembled to monitor and analyze some of the ecological consequences of photochemical oxidant air pollutants in California Mixed Conifer Forest ecosystems of the San Bernardino Mountains east of Los Angeles. The purposes included g...

288

Evapotranspiration models compared on a Sierra Nevada forest ecosystem  

E-print Network

and Management, Forest Science Division, University of California, 151 Hilgard Hall, Berkeley, CA 94720-3114, USA are research forests across the United States, Canada, Brazil, and Costa Rica with instruments on towersEvapotranspiration models compared on a Sierra Nevada forest ecosystem Joshua B. Fisher*, Terry A

Cohen, Ronald C.

289

California Dust  

... View Larger Image Southern California's "Santa Anas" are dry, north-easterly winds having speeds in excess of 25 knots (46 kilometers/hour). Santa Ana conditions are commonly associated with gusts of more than twice this ...

2014-05-15

290

Transforming California  

NSDL National Science Digital Library

Transforming California is a PowerPoint presentation of digital images (60.7 Mb) exploring the landforms found along the San Andreas Fault. Designed for classroom use, this slideshow provides a complementing narrative for each slide.

Mcguire, Thomas

2001-01-01

291

California Fires  

article title: Smoke from Station Fire Blankets Southern California ... 105,000 acres (164 square miles) of the Angeles National Forest by mid-day August 31, destroying at least 21 homes and threatening more ...

2014-05-15

292

Combined climate- and prey-mediated range expansion of Humboldt squid (Dosidicus gigas), a large marine predator in the California Current System.  

PubMed

Climate-driven range shifts are ongoing in pelagic marine environments, and ecosystems must respond to combined effects of altered species distributions and environmental drivers. Hypoxic oxygen minimum zones (OMZs) in midwater environments are shoaling globally; this can affect distributions of species both geographically and vertically along with predator-prey dynamics. Humboldt (jumbo) squid (Dosidicus gigas) are highly migratory predators adapted to hypoxic conditions that may be deleterious to their competitors and predators. Consequently, OMZ shoaling may preferentially facilitate foraging opportunities for Humboldt squid. With two separate modeling approaches using unique, long-term data based on in situ observations of predator, prey, and environmental variables, our analyses suggest that Humboldt squid are indirectly affected by OMZ shoaling through effects on a primary food source, myctophid fishes. Our results suggest that this indirect linkage between hypoxia and foraging is an important driver of the ongoing range expansion of Humboldt squid in the northeastern Pacific Ocean. PMID:24443361

Stewart, Julia S; Hazen, Elliott L; Bograd, Steven J; Byrnes, Jarrett E K; Foley, David G; Gilly, William F; Robison, Bruce H; Field, John C

2014-06-01

293

Refocusing Mussel Watch on contaminants of emerging concern (CECs): the California pilot study (2009-10).  

PubMed

To expand the utility of the Mussel Watch Program, local, regional and state agencies in California partnered with NOAA to design a pilot study that targeted contaminants of emerging concern (CECs). Native mussels (Mytilus spp.) from 68 stations, stratified by land use and discharge scenario, were collected in 2009-10 and analyzed for 167 individual pharmaceuticals, industrial and commercial chemicals and current use pesticides. Passive sampling devices (PSDs) and caged Mytilus were co-deployed to expand the list of CECs, and to assess the ability of PSDs to mimic bioaccumulation by Mytilus. A performance-based quality assurance/quality control (QA/QC) approach was developed to ensure a high degree of data quality, consistency and comparability. Data management and analysis were streamlined and standardized using automated software tools. This pioneering study will help shape future monitoring efforts in California's coastal ecosystems, while serving as a model for monitoring CECs within the region and across the nation. PMID:23886247

Maruya, Keith A; Dodder, Nathan G; Schaffner, Rebecca A; Weisberg, Stephen B; Gregorio, Dominic; Klosterhaus, Susan; Alvarez, David A; Furlong, Edward T; Kimbrough, Kimani L; Lauenstein, Gunnar G; Christensen, John D

2014-04-30

294

Coral Reef Ecosystems  

NSDL National Science Digital Library

The Coral Reef Ecosystems SciPack explores the unique and diverse ecosystem of the coral reef. The focus is on Standards and Benchmarks related to populations and ecosystems using coral reefs and their immediate environment as an example. Because the Standards and Benchmarks present the concepts of populations and ecosystems generically, without reference to a specific ecosystem or the organisms in the system, coral reefs are used to provide the context through which concepts in a marine ecosystem are explored.In addition to comprehensive inquiry-based learning materials tied to Science Education Standards and Benchmarks, the SciPack includes the following additional components:� Pedagogical Implications section addressing common misconceptions, teaching resources and strand maps linking grade band appropriate content to standards. � Access to one-on-one support via e-mail to content "Wizards".� Final Assessment which can be used to certify mastery of the concepts.Learning Outcomes:Coral Reef Ecosystems: The Living Reef� Identify coral polyp structures and describe their functions.� Describe photosynthesis in the coral environment.� Describe the evolution of a typical reef system.� Use the shape of an individual coral to identify its common name, and classify entire coral reef ecosystems based on shape and location. � Describe the process of coral polyp reproduction and growth.� Identify how the features and/or behavioral strategies of coral reef inhabitants enable them to survive in coral reef environments.Coral Reef Ecosystems: The Abiotic Setting� Identify the characteristics of an ecosystem, and describe the interdependence between biotic and abiotic features in an ecosystem.� Describe how the following abiotic factors provide coral with the energy needed to survive and grow within their ecosystem: sunlight, water, oxygen, and carbon dioxide.� Describe the optimal environmental conditions for coral reef growth, and explain the process of coral reef development (including the role of available sunlight and calcium).� Explain how the following environmental factors might affect coral ecosystems: increase in dissolved CO2, changes in global temperatures, increase in ocean water turbidity through water pollution.Coral Reef Ecosystems: Interdependence� Identify and label key components of food chains and food webs in a coral reef ecosystem.� Describe key relationships among plants and animals in the coral reef ecosystem: predator and prey relationships, producer and consumer relationships, and symbiotic relationships (mutualism, commensalisms, parasitism).� Recognize the direction that energy travels through food chains and food webs.� Explain that materials (chemical elements) and natural resources are recycled in coral reef ecosystems and reappear in different forms.� Describe the primary ecological succession events within a typical coral reef ecosystem.Coral Reef Ecosystems: Ecosystems in Crisis� Describe ways in which human activities directly impact coral reef ecosystems (resource and recreational uses).� Describe ways in which human activities indirectly impact coral reef ecosystems (by changing the physical conditions, pollution, changes in the water chemistry, etc.).� Explain how human activity may decrease the reefs ability to recover from natural occurrences. � Explain the effects of increased predation or disease on a reef ecosystem.� Describe the effect of habitat loss on the reef ecosystem.� Describe the effects of weather and climate change on a healthy and weakened reef ecosystem.

National Science Teachers Association (NSTA)

2007-03-28

295

Pacific Northwest Coastal Ecosystems Regional Study (PNCERS)  

NSDL National Science Digital Library

The Pacific Northwest Coastal Ecosystems Regional Study (PNCERS) is a joint effort of the Oregon Coastal Management Program, the Washington Sea Grant Program, and the National Marine Fisheries Service. Funded by the National Oceanic and Atmospheric Administration (NOAA), PNCERS conducts research and outreach projects in the nearshore and estuarine ecosystems of the Pacific Coast. The PNCERS homepage includes a brief overview of current projects, metadata from several projects, PNCERS publications, and a selection of useful links.

296

Effects of ozone on ecosystems -- ecosystem indicators of concern  

SciTech Connect

Ozone has been recognized as an important cause of damage to crops since the 1950s. Damage to trees was first identified in the 1960s and is now known to be widespread in both North America and Europe. Most impact studies have emphasized the importance of determining growth losses attributable to ozone and as a result have concentrated on species of commercial importance. This is illustrated by the critical loads approach to ozone risk assessment in Europe, which is currently based on the AOT40 -- 10 ppmh threshold. At higher levels, it has been argued that a 10% growth reduction occurs in European beech (Fagus sylvatica). Such an approach suffers from a number of serious limitations, not least the widespread impacts on ecosystems that may occur at lower ozone exposures and the very poor quantitative basis for setting this threshold. In Europe, there has been increasing emphasis on the conservation and management of species without any direct economic importance. This has arisen from a growing environmental awareness of the general public. The trend has been accelerated by the perceived environmental benefits of the large amounts of land that has been taken out of agricultural production (as a result of the ``set-aside`` policy of the European Union) and the public concern about the ecological and environmental impacts of industrial forestry. In agricultural landscapes, hedgerow species and weed species are being looked at as important parts of the agricultural ecosystem. In particular, weed species are an important part of the food chain for the wildlife present in such ecosystems. In forests, much greater emphasis is being given to the authenticity of the forest ecosystems. Particular emphasis is being given to ecosystem management techniques such as continuous cover forestry and the furthering of natural regeneration.

Innes, J.L. [Swiss Federal Inst. for Forest, Snow and Landscape Research, Birmensdorf (Switzerland)

1998-12-31

297

An analysis of HF radar measured surface currents to determine tidal, wind-forced, and seasonal circulation in the Gulf of the Farallones, California, United States  

Microsoft Academic Search

A complete year of hourly 3 km resolution high-frequency radar measured surface currents covering the Gulf of the Farallones were analyzed with the following three primary objectives: (1) describe the seasonal surface circulation, (2) identify tidal currents, and (3) determine the influence of wind forcing. Three predominant seasonal circulation regimes were identified: relaxation, storm, and upwelling. The relaxation period exhibited

Matt K. Gough; Newell Garfield; Erika McPhee-Shaw

2010-01-01

298

Emergy and ecosystem complexity  

NASA Astrophysics Data System (ADS)

The question "What drives complexity?" is addressed in this paper. To answer this question, we explore the way energy and material resources of different quality flow through ecosystems and support, directly and indirectly, ecosystems growth and development. Processes of resource transformation throughout the ecosystem build order, cycle materials, generate and sustain information. Energy drives all these processes and energetic principles explain much of what is observed, including energy degradation according to the laws of thermodynamics. Emergy, a quantitative measure of the global environmental work supporting ecosystem dynamics, is used here in order to provide a deeper understanding of complexity growth and decline in ecosystems. Ecosystem complexity is discussed in this paper in relation to changes in structure, organization and functional capacity, as explained by changes in emergy, empower, and transformity.

Ulgiati, Sergio; Brown, Mark T.

2009-01-01

299

Ecosystem Services - Water Purification  

NSDL National Science Digital Library

This lesson, provided by Science NetLinks, teaches students the importance of healthy ecosystems by investigating the example of natural water purification. Students will learn how ecosystems remove pollution from the water and how much it costs humans to do this artificially once ecosystems are no longer healthy. The class will then create a "River Newspaper" reporting on the condition of the local environment.

Science Netlinks;

2002-06-30

300

Baltic Ecosystem Adaptive Management  

E-print Network

1 Baltic Ecosystem Adaptive Management ?stersjöforskning för en hållbar förvaltning av havet #12;2 Baltic Ecosystem Adaptive Management, BEAM, är ett tvärvetenskapligt forskningsprogram med målet att vårt unika innanhav beror mycket på hur vi väljer att vårda det. Baltic Ecosystem Adaptive Management

301

Linking the Seasonal Variation of Vegetation Indices to Tower Flux Measurements in an Oak-Savanna Ecosystem in California: Comparing the Performance of Ground Based Sensors to Remotely Sensed Products from MODIS, AVIRIS and IKONOS.  

NASA Astrophysics Data System (ADS)

Across the globe, there are now over 200 FLUXNET sites sampling tower fluxes over many vegetation types. However the spatial resolution of the tower sites is limited and additional information is needed to provide the Global Change Research community with an accurate way to identify and quantify carbon sources and sinks on regional, continental and global scales. Remote sensing is a major tool capable of providing information about the dynamics of the terrestrial biosphere with continuous spatial and temporal coverage on a global scale. For this purpose vegetation indices are chosen specifically to enhance the contribution of vegetation properties to surface reflectances. Remote sensing products generally produce information on GPP (or net primary productivity, NPP), in terms of a light use efficiency (?) and the amount of absorbed visible sunlight (fPAR). Linking remote sensing with FLUXNET sites is crucial in providing reliable estimates of the magnitude and dynamics of the terrestrial carbon budget. An important issue is the spatial mismatch between the NASA Moderate Resolution Imaging Spectrometer (MODIS) and the footprint of tower observations. In this study we have conducted seasonal observations of VI's using three different ground based sensors: a high resolution spectrometer on a weekly basis, and a spectrally-selective light emitting diode spectrometer and a broadband radiometer providing continuous measurements for a highly dynamic oak-savanna ecosystem. We investigate seasonal changes in ?, drought induced changes in carbon uptake (NEE) and their link to different VI's like the Normalized Differential Vegetation Index (NDVI), Enhanced Vegetation Index (EVI) and the Photochemical Reaction Index (PRI). Using a combination of spatially coarse MODIS data with high resolution snapshots from IKONOS and AVIRIS platforms together with the ground based spectral observations, we expand the tower site results to regional scale. We find that NDVI is an overall poor correlator with NEE for the dynamic grassland with pronounced winter time photosythesis and extensive drought stress. EVI and especially PRI provide better linkage of spectral reflectance data to the actual photosynthetic activity of the grassland ecosystem.

Falk, M.; Baldocchi, D. D.; Mercado, I. R.; Ma, S.; Hehn, T.

2005-12-01

302

California coastal processes study  

NASA Technical Reports Server (NTRS)

Preliminary findings are presented and applications derived from ERTS-1 satellite imagery of the nearshore coastal processes of the California coast. The objectives were to analyze nearshore currents, sediment transport, and estuarine and river discharges along the California coast through the use of synoptic and repetitive imagery from ERTS as well as aircraft underflights and surface data. The major conclusions are: (1) Distinct seasonal patterns for sediment transport as a function of the oceanic current systems and coastal morphology have been identified. (2) Large scale sediment plumes from intermittent streams and rivers extend offshore to previously unanticipated ranges. (3) Computer generated contouring of radiance levels from computer-compatible tapes result in charts that can be used for determination of surface and nearsurface suspended sediment distribution. (4) Flying spot scanner enhancements result in details of nearshore features. (5) Data is providing significant information for coastal planning and construction projects.

Pirie, D. M.; Steller, D. D.

1974-01-01

303

Hydroelectric power in California  

Microsoft Academic Search

The hydroelectric power potential of California was examined and the problems related to the development of that potential reviewed. The generating capacity of 173 existing conventional hydro power plants is 8500 MWe. Conventional hydroelectric power development is expected to add between 0.2 and 0.4 quads (20 x 10⁹ to 40 x 10⁹ kWh) per year to the current hydroelectric supply

1979-01-01

304

Multiple states in river and lake ecosystems.  

PubMed Central

Nonlinear models of ecosystem dynamics that incorporate positive feedbacks and multiple, internally reinforced states have considerable explanatory power. However, linear models may be adequate, particularly if ecosystem behaviour is primarily controlled by external processes. In lake ecosystems, internal (mainly biotic) processes are thought to have major impacts on system behaviour, whereas in rivers, external (mainly physical) factors have traditionally been emphasized. We consider the hypothesis that models that exhibit multiple states are useful for understanding the behaviour of lake ecosystems, but not as useful for understanding stream ecosystems. Some of the best-known examples of multiple states come from lake ecosystems. We review some of these examples, and we also describe examples of multiple states in rivers. We conclude that the hypothesis is an oversimplification; the importance of physical forcing in rivers does not eliminate the possibility of internal feedbacks that create multiple states, although in rivers these feedbacks are likely to include physical as well as biotic processes. Nonlinear behaviour in aquatic ecosystems may be more common than current theory indicates. PMID:12079525

Dent, C Lisa; Cumming, Graeme S; Carpenter, Stephen R

2002-01-01

305

of California  

E-print Network

to conserving birds, other wildlife and ecosystems through innovative scientific research and outreach. Contact Us Help support PRBOs mission to conserve birds and their ecosystms through research and outreach. You can join online at www.prbo.org. To receive additional copies of this guide, please call PRBO Conservation Science (PRBO) at (707) 781-2555 x 354. For more information about PRBOs efforts to understand and protect Pacific Coast beachesand ecosystem conservation projects throughout the Westvisit www.prbo.org. Give us your feedback at www.prbo.org/feedback. Copyright 2009 by

unknown authors

306

Hawaiian Ecosystems at Risk Project  

NSDL National Science Digital Library

The Hawaiian Ecosystems at Risk Project works "to provide technology, methods, and information to decision-makers, resource managers, and the general public to help support effective science-based management of harmful non-native species in Hawaii and the Pacific." Current and past supporters of the HEAR project include the U.S. Geologic Survey, Pacific Island Ecosystems Research Center, University of Hawaii, National Biological Information Infrastructure-Pacific Basin Information Node, and others. The HEAR website links to a plethora of online resources including: full-text articles and reports, an Alien Species in Hawaii Information Index, A Global Compendium of Weeds, literature references, species fact sheets, numerous images, and more. HEAR also hosts electronic mailing lists, and bulletin boards for both job and general announcements including postings for professional meetings, and research grant opportunities.

307

Evaluating the Spatial Distribution of Toxic Air Contaminants in Multiple Ecosystem Indicators in the Sierra Nevada-Southern Cascades  

NASA Astrophysics Data System (ADS)

Toxic air contaminants originating from agricultural areas of the Central Valley in California threaten vulnerable sensitive receptors including surface water, vegetation, snow, sediments, fish, and amphibians in the Sierra Nevada-Southern Cascades region. The spatial distribution of toxic air contaminants in different ecosystem indicators depends on variation in atmospheric concentrations and deposition, and variation in air toxics accumulation in ecosystems. The spatial distribution of organic air toxics and mercury at over 330 unique sampling locations and sample types over two decades (1990-2009) in the Sierra Nevada-Southern Cascades region were compiled and maps were developed to further understand spatial patterns and linkages between air toxics deposition and ecological effects. Potential ecosystem impacts in the Sierra Nevada-Southern Cascades region include bioaccumulation of air toxics in both aquatic and terrestrial ecosystems, reproductive disruption, and immune suppression. The most sensitive ecological end points in the region that are affected by bioaccumulation of toxic air contaminants are fish. Mercury was detected in all fish and approximately 6% exceeded human consumption thresholds. Organic air toxics were also detected in fish yielding variable spatial patterns. For amphibians, which are sensitive to pesticide exposure and potential immune suppression, increasing trends in current and historic use pesticides are observed from north to south across the region. In other indicators, such as vegetation, pesticide concentrations in lichen increase with increasing elevation. Current and historic use pesticides and mercury were also observed in snowpack at high elevations in the study area. This study shows spatial patterns in toxic air contaminants, evaluates associated risks to sensitive receptors, and identifies data gaps. Future research on atmospheric modeling and information on sources is needed in order to predict which ecosystems are the most sensitive to toxic air contaminants in the Sierra Nevada-Southern Cascades region.

Nanus, L.; Simonich, S. L.; Rocchio, J.; Flanagan, C.

2013-12-01

308

Ecosystems, Teacher's Guide.  

ERIC Educational Resources Information Center

The Science Curriculum Improvement Study has developed this teacher's guide to "Ecosystems," the sixth part of a six unit life science curriculum sequence. The six basic units, emphasizing organism-environment interactions, are organisms, life cycles, populations, environments, communities, and ecosystems. They make use of scientific and

California Univ., Berkeley. Science Curriculum Improvement Study.

309

Exploring virtual ecosystems  

Microsoft Academic Search

Browsing In Time & Space (BITS) is an interface designed to explore virtual ecosystems. A virtual ecosystem includes a three dimensional terrain model background, collections of man-made and natural objects, and behavior and interaction rules between the objects and the background. BITS is based on a virtual notepad and pen metaphor and is inspired in the concept of logging. Physical

Anto Vaz Almada; Antnio Eduardo Dias; Joo Pedro Silva; Emanuel Marques dos Santos; Pedro Jos Pedrosa; Antnio Sousa Cmara

1996-01-01

310

Graduate studies Ecosystem Science  

E-print Network

Graduate studies in Ecosystem Science and Management Ph.D. M.S. M.Agr. or Natural Resources Development MNRD Department of Ecosystem Science and Management College of Agriculture and Life Sciences. The thesisbased Master of Science and Ph.D. degrees are designed for research or academic careers

311

Earth on Edge : Ecosystems  

NSDL National Science Digital Library

This site provides information about the six ecosystems on which life on Earth most heavily depends: agricultural, forest, freshwater, grassland, coastal, and urban. It is part of a Public Broadcasting System (PBS) project, which includes a discussion guide. Ecosystems are described as communities of interacting organisms and the physical environment in which they live. The goods and services that ecosystems provide are said to form the foundation of human economies. Ecosystems purify air and water, help to control climate, and produce valuable soil-services. Site users may access a discussion guide to accompany the broadcast of the video/television program, which can be used in colleges, secondary schools, and in community groups. Case studies are taken from the companion book, World Resources 2000-2001: Ecosystems and People: The Fraying Web of Life, and from Pilot Analysis of Global Ecosystems: Agroecosystems (World Resources Institute). This online text includes profiles, case studies, and ecosystem assessments with references to ecosystems around the world. A list of additional resources includes links to environmental organizations, books, and periodicals.

Mock, Gregory; Vanasselt, Wendy

2000-01-01

312

The Library as Ecosystem  

ERIC Educational Resources Information Center

Ecology is the study of interactions between organisms and their environment, and the academic library could be considered to be an ecosystem, i.e., a "biological organization" in which multiple species must interact, both with one another and with their environment. The metaphor of the library as ecosystem is flexible enough to be applied not

Walter, Scott

2008-01-01

313

Ecosystems, externalities, and economies  

Microsoft Academic Search

This paper incorporates an ecosystem model into a model of a simple economy. The decisionmaking agents in the ecosystem are individual organisms aggregated to the species level. A species may provide utility directly to humans, or it may provide utility indirectly because it is used either as a raw material in goods fabrication or as sustenance for other species. We

Thomas D. Crocker; John Tschirhart

1992-01-01

314

Ecosystem Viable Yields  

E-print Network

The World Summit on Sustainable Development (Johannesburg, 2002) encouraged the application of the ecosystem approach by 2010. However, at the same Summit, the signatory States undertook to restore and exploit their stocks at maximum sustainable yield (MSY), a concept and practice without ecosystemic dimension, since MSY is computed species by species, on the basis of a monospecific model. Acknowledging this gap, we propose a definition of "ecosystem viable yields" (EVY) as yields compatible i) with biological viability levels for all time and ii) with an ecosystem dynamics. To the difference of MSY, this notion is not based on equilibrium, but on viability theory, which offers advantages for robustness. For a generic class of multispecies models with harvesting, we provide explicit expressions for the EVY. We apply our approach to the anchovy--hake couple in the Peruvian upwelling ecosystem between the years 1971 and 1981.

De Lara, Michel; Oliveros-Ramos, Ricardo; Tam, Jorge

2011-01-01

315

-California -Washington  

E-print Network

Pacific - California - Oregon - Washington 23 #12;Regional Summary Pacific Pacific Fishery, and Washington. Federal fisheries in this region are managed by the Pacific Fishery Management Council (PFMC of Oregon and Washington and their incidental harvest is an example of bycatch. Interesting management

316

CALIFORNIA ENERGY COMMISSION California Energy Commission  

E-print Network

, CALIFORNIA CENTER FOR SUSTAINABLE ENERGY, CALIFORNIA ENVIRONMENTAL JUSTICE ALLIANCE, CALIFORNIA SOLAR ENERGY., LOCAL ENERGY AGGREGATION NETWORK, DR. LUIS PACHECO, PRESENTE.ORG, SIERRA CLUB, SOLAR ENERGY INDUSTRIES ASSOCIATION, AND THE VOTE SOLAR INITIATIVE FOR SOCIETAL COST-BENEFIT EVALUATION OF CALIFORNIA'S NET ENERGY

317

Ecosystem Restoration through Interdisciplinary Exchange  

E-print Network

Ecosystem Restoration through Interdisciplinary Exchange David M. Blersch dblersch Shade of Blue and You 21 September 2010 #12;National Science Foundation Ecosystem Restoration through;National Science Foundation Ecosystem Restoration through Interdisciplinary Exchange UB's ERIE Program www

Sachs, Frederick

318

SEVEN PILLARS OF ECOSYSTEM MANAGEMENT  

EPA Science Inventory

Ecosystem management is widely proposed in the popular and professional literature as the modern and preferred way of managing natural resources and ecosystems. Advocates glowingly describe ecosystem management as an approach that will protect the environment, maintain healthy ec...

319

Emergent Global Patterns of Ecosystem Structure and Function from a Mechanistic General Ecosystem Model  

PubMed Central

Anthropogenic activities are causing widespread degradation of ecosystems worldwide, threatening the ecosystem services upon which all human life depends. Improved understanding of this degradation is urgently needed to improve avoidance and mitigation measures. One tool to assist these efforts is predictive models of ecosystem structure and function that are mechanistic: based on fundamental ecological principles. Here we present the first mechanistic General Ecosystem Model (GEM) of ecosystem structure and function that is both global and applies in all terrestrial and marine environments. Functional forms and parameter values were derived from the theoretical and empirical literature where possible. Simulations of the fate of all organisms with body masses between 10 g and 150,000 kg (a range of 14 orders of magnitude) across the globe led to emergent properties at individual (e.g., growth rate), community (e.g., biomass turnover rates), ecosystem (e.g., trophic pyramids), and macroecological scales (e.g., global patterns of trophic structure) that are in general agreement with current data and theory. These properties emerged from our encoding of the biology of, and interactions among, individual organisms without any direct constraints on the properties themselves. Our results indicate that ecologists have gathered sufficient information to begin to build realistic, global, and mechanistic models of ecosystems, capable of predicting a diverse range of ecosystem properties and their response to human pressures. PMID:24756001

Emmott, Stephen; Hutton, Jon; Lyutsarev, Vassily; Smith, Matthew J.; Scharlemann, Jorn P. W.; Purves, Drew W.

2014-01-01

320

Macrofaunal Succession and Community Structure in Salicornia Marshes of Southern California  

Microsoft Academic Search

Lack of basic understanding of ecosystem structure and function forms a major impediment to successful conservation of coastal ecosystems. This paper provides a description of the fauna and examines faunal succession inSalicornia -vegetated sediments of southern California. Environmental attributes (vegetation and sediment properties) and macrofaunal (animals ?03mm) community structure were examined in sediments of five natural, southern CaliforniaSalicornia spp. marshes

T. S. Talley; L. A. Levin

1999-01-01

321

Ecosystem Responses to Global Climate Change: Moving Beyond Color Mapping  

NSDL National Science Digital Library

This peer-reviewed article from BioScience is on the effects of climate change on ecosystems. Current assessments of climate-change effects on ecosystems use two key approaches: (1) empirical synthesis and modeling of species range shifts and life-cycle processes that coincide with recent evidence of climate warming, from which scenarios of ecosystem change are inferred; and (2) experiments examining plant-soil interactions under simulated climate warming. Both kinds of assessment offer indisputable evidence that climate change and its effects on ecosystems are ongoing. However, both approaches often provide conservative estimates of the effects of climate change on ecosystems, because they do not consider the interplay and feedback among higher trophic levels in ecosystems, which may have a large effect on plant species composition and on ecosystem services such as productivity. Understanding the impacts of these top-down processes on ecosystems is critical for determining large-scale ecosystem response to climate change. Using examples of links between climate forcing, trophic interactions, and changes in ecosystem state in selected terrestrial, freshwater, and marine systems, we show that the ability to understand and accurately forecast future effects of climate change requires an integrated perspective, linking climate and the biotic components of the ecosystem as a whole.

OSWALD J. SCHMITZ, ERIC POST, CATHERINE E. BURNS, and KEVIN M. JOHNSTON (;)

2003-12-01

322

Synergistic Effects of Climate and Fishing in a Marine Ecosystem  

Microsoft Academic Search

Current climate change and overfishing are affecting the productivity and structure of marine ecosystems. This situation is\\u000a unprecedented for the marine biosphere and it is essential to understand the mechanisms and pathways by which ecosystems respond.\\u000a We report that climate change and overfishing are likely to be responsible for a rapid restructuring of a highly productive\\u000a marine ecosystem with effects

Richard R. Kirby; Gregory Beaugrand; John A. Lindley

2009-01-01

323

Coral Reef Ecosystems: Interdependence  

NSDL National Science Digital Library

This Science Object is the third of four Science Objects in the Coral Reef Ecosystems SciPack. It explores the interdependent relationships between species in the coral reef ecosystem. All populations in the reef ecosystem are a part of and depend on a global food web (a connected set of food chains) through which energy flows in one direction, from the sun into organism and eventually dissipating into the environment as heat. This food web includes ocean plants, the animals that feed on them, and the animals that feed on those animals. Energy is transferred between organisms and their environment along the way. Energy concentration diminishes at each step. The cycles of life continue indefinitely because organisms decompose after death and return food materials to the environment. Learning Outcomes:� Identify and label key components of food chains and food webs in a coral reef ecosystem.� Describe key relationships among plants and animals in the coral reef ecosystem: predator and prey relationships, producer and consumer relationships, and symbiotic relationships (mutualism, commensalisms, parasitism).� Recognize the direction that energy travels through food chains and food webs.� Explain that materials (chemical elements) and natural resources are recycled in coral reef ecosystems and reappear in different forms.� Describe the primary ecological succession events within a typical coral reef ecosystem.

National Science Teachers Association (NSTA)

2006-11-01

324

Pathways for School Finance in California  

ERIC Educational Resources Information Center

California's budget crisis has diminished educational resources for the state's current cohort of public school students. Because school districts have less revenue, class sizes are larger and struggling students receive less assistance. Under these circumstances, it seems beside the point to suggest that California should begin planning for the

Rose, Heather; Sonstelie, Jon; Weston, Margaret

2010-01-01

325

Multicultural Graduation Requirements among California's Community Colleges  

ERIC Educational Resources Information Center

This examination of the current status of multicultural education among California community colleges emerged from a perspective that the inclusion of multicultural education has become a major goal of California's leaders within the past five years. The literature revealed minority students tend to have lower retention rates because they become

Hess, Shelly L.; Uerling, Donald F.; Piland, William E.

2012-01-01

326

CALIFORNIA ENERGY COMMISSION NEW CONSTRUCTION ENERGY AUDITS  

E-print Network

of the State Architect, and the California Department of Education to ensure that recommended projects meet and leaving more money for education. Many new schools being built today just barely meet current California Program provides technical assistance to your district's architectural and engineering team early

327

CALIFORNIA'S NEXT GENERATION OF LOAD MANAGEMENT STANDARDS  

E-print Network

response at the top of the resource procurement loading order with energy efficiency. It specifies to its current state, provides a history of the Energy Commission's load management authorityCALIFORNIA'S NEXT GENERATION OF LOAD MANAGEMENT STANDARDS Prepared For: California Energy

328

Linking the Response of Annual Grasslands to Warming and Altered Rainfall Across Scales of Gene Expression, Species, and Ecosystem  

Microsoft Academic Search

Climate change can influence terrestrial ecosystems at multiple biological levels: gene expression, species, and ecosystem. We are studying California grassland mesocosms with seven annual species (five grasses, two forbs) that were started in 2005. In the 2006-2007 growing season, they were exposed to three rainfall treatments (297, 552, and 867 mm y-1) and soil and air temperature (ambient and elevated

M. S. Torn; S. M. Bernard; C. Castanha; M. L. Fischer; F. M. Hopkins; S. A. Placella; S. B. St. Clair; R. Salve; E. Sudderth; D. Herman; D. Ackerly; M. K. Firestone

2007-01-01

329

CALIFORNIA ENERGY COMMISSIONCOMMISSION  

E-print Network

organizationsg Prepare veterans and disadvantaged youth for employment · $5M: California Conservation CorpsCALIFORNIA ENERGY COMMISSIONCOMMISSION California Clean Energy Jobs Act: Proposition 39 Draft MEETINGMEETING AGENDA · Summary of California Clean Energy Jobs Act· Summary of California Clean Energy Jobs Act

330

Homelessness in California  

E-print Network

among the poor--is forcing lower-income families to "buy down" as a result of higher housing prices--California. 2. Homeless persons--Housing--California. 3. Homeless persons--Services for--California. 4. Low-income housing-- California. 5. Housing policy--California. I. Raphael, Steven, 1968­. II. Smolensky, Eugene. III

Sekhon, Jasjeet S.

331

National Geographic Education: Ecosystems  

NSDL National Science Digital Library

The National Geographic Education website has a number of sections dedicated to different areas within the natural sciences. This particular section brings together all manner of educational resources related to ecosystems. On the site, visitors can dive in via the Latest Updates for Ecosystems. Here they can learn how to explore the profiled ecosystems via a range of GIS tools. Visitors can use the filters on the site to look over the resources by Type, Grades & Ages, Intended Audience, and Subjects. Visitors shouldn't miss looking over features like the Amazon Gold Mine, Back to the Bottom, and African Savanna.

2013-06-13

332

Pathways for School Finance in California. Technical Appendix  

ERIC Educational Resources Information Center

This is a technical appendix for the report, "Pathways for School Finance in California" (ED515651). "Pathways for School Finance in California" simulates alternatives to California's current school finance system. This appendix provides more information about the revenues used in those simulations. The first section describes the districts and

Rose, Heather; Sonstelie, Jon; Weston, Margaret

2010-01-01

333

Current titles  

SciTech Connect

This booklet is published for those interested in current research being conducted at the National Center for Electron Microscopy. The NCEM is a DOE-designated national user facility and is available at no charge to qualified researchers. Access is controlled by an external steering committee. Interested researchers may contact Gretchen Hermes at (510) 486-5006 or address below for a User`s Guide. Copies of available papers can be ordered from: Theda Crawford National Center for Electron Microscopy, Lawrence Berkeley Laboratory, One Cyclotron Rd., MS72, Berkeley, California, USA 94720.

NONE

1995-07-01

334

Objects or Ecosystems? Giant Sequoia Management in National Parks  

NSDL National Science Digital Library

This is a 1992 paper on policies and programs aimed at protecting giant sequoia (Sequoiadendron giganteum) in the national parks of the California Sierra Nevada: Yosemite, Kings Canyon, and Sequoia. The policies have evolved from the protection of individual trees to the preservation of entire ecosystems. National Park Service management strategies for giant sequoia focus on the restoration of native ecosystem processes. This includes the use of prescribed fire to simulate natural ignitions. Basic research is being carried out to improve our understanding of the factors influencing giant sequoia reproduction, growth, and survival.

Parsons, David

335

California Shipwrecks  

NSDL National Science Digital Library

This new site from the California State Lands Commission offers a nice collection of resources for actual or armchair underwater archaeologists. The core of the site is a database of over 1500 California shipwrecks, searchable by keyword in twelve fields. Search returns include ship's name, type, years built and sunk, cause, owner, captain, length, beam, tonnage, engine, and county. The other major feature at the site is an exhibition on the wreck and recovery of the Brother Jonathan. The exhibit includes the story of the ship and its specifications, a passenger list, a photo exhibit of artifacts and video of the wreck, and some comments on the significance of the archaeological remains. Other sections of the site include brief articles on the sinking of eight ships, video and audio clips, and links to related sites.

336

Brown v. Plata: prison overcrowding in California.  

PubMed

California's prisons are currently designed to house approximately 85,000 inmates. At the time of the U.S. Supreme Court's 2011 decision in Brown v. Plata, the California prison system housed nearly twice that many (approximately 156,000 inmates). The Supreme Court held that California's prison system violated inmates' Eighth Amendment rights. The Court upheld a three-judge panel's order to decrease the population of California's prisons by an estimated 46,000 inmates. They determined that overcrowding was the primary cause of the inmates' inadequate medical and mental health care. As a result, the California Department of Corrections and Rehabilitation (CDCR) has been working to redistribute inmates and parolees safely and decrease the overall population to the mandated levels. These large-scale adjustments to California's penal system create potential opportunities to study the long-term effects on affected inmates. PMID:23233477

Newman, William J; Scott, Charles L

2012-01-01

337

Is Net Ecosystem Production Equal to Ecosystem Carbon Accumulation?  

E-print Network

COMMENTARY Is Net Ecosystem Production Equal to Ecosystem Carbon Accumulation? Gary M. Lovett,* Jonathan J. Cole, and Michael L. Pace Institute of Ecosystem Studies, Millbrook, New York 12545, USA ABSTRACT Net ecosystem production (NEP), defined as the difference between gross primary production

Pace, Michael L.

338

Analyzing an Ecosystem  

NSDL National Science Digital Library

In this interactive activity adapted from the University of Alberta, identify the living and nonliving things in an ecosystem. Then look further at the living things to identify the producers, the consumers, and examples of mimicry.

Foundation, Wgbh E.

2007-08-09

339

Ecosystems in the Laboratory  

ERIC Educational Resources Information Center

Describes the materials and laboratory techniques for the study of food chains and food webs, pyramids of numbers and biomass, energy pyramids, and oxygen gradients. Presents a procedure for investigating the effects of various pollutants on an entire ecosystem. (GS)

Madders, M.

1975-01-01

340

Allelopathy in Forested Ecosystems  

Microsoft Academic Search

In the context of forestry, the concept of allelopathy has recently been expanded from a plant to plant interference phenomenon\\u000a to an ecosystem-level phenomenon that is influenced by ecosystem disturbance. This chapter reviews the latest development\\u000a in our understanding of forest allelopathy and the ways in which this new knowledge can be used in sustainable forest management.\\u000a Allelopathic effects of

Azim U. Mallik

341

Limiting Factors in Ecosystems  

NSDL National Science Digital Library

This unit, designed to span two class periods, helps students understand that physical factors, particularly temperature and precipitation, limit the growth of plant ecosystems. The activity begins with a discussion in which students develop their own ideas about the role of temperature, precipitation, and environment on plant growth. They will then examine X-Y graphs of vegetation growth, temperature, and precipitation versus month for four diverse ecosystems to determine which climatic factor is limiting growth. A worksheet and scoring rubric are provided.

342

IS THERE EVIDENCE FOR LONG-TERM CLIMATIC CHANGE IN SOUTHERN CALIFORNIA KELP FORESTS?  

Microsoft Academic Search

Evidence for long-term natural change in coastal ecosystems has to be separated from the effects of in- tense anthropogenic impacts, especially in heavily pop- ulated areas. The kelp forests of southern California, highly productive ecosystems organized around the giant kelp, Mucvocystis pyrijeferu, support a variety of fisheries, and the kelp is harvested for extraction of alginates. Because of the importance

MIA J TEGNER; PAUL K DAYTON; PETER B EDWAKDS; KRISTIN L RISER

1996-01-01

343

Trophic cycling and carbon export relationships in the California Current Ecosystem Michael R. Stukel,a,*,1 Michael R. Landry,a Claudia R. Benitez-Nelson,b and Ralf Goerickea  

E-print Network

by the 234Th method taken during Lagrangian experiments. To assess trophic relationships, we simultaneously and the variability found in contemporaneous measurements of 234Th export and C : 234Th-ratios of sinking particles. E

Benitez-Nelson, Claudia

344

Rust and Beetle Interactions in Pinus albicaulis Ecosystems  

Microsoft Academic Search

Current mountain pine beetle activity in whitebark pine ecosystems in the Greater Yellowstone Ecosystem is unprecedented in extent and severity. Dynamics among beetles, white pine blister rust, and climate change are placing this foundation species in a precarious state. Stand- and tree-level data was recorded to quantify how the severity of rust and the presence of an alternate host influence

Nancy Bockino; Daniel B. Tinker

2009-01-01

345

Positive feedback between increasing atmospheric CO2 and ecosystem productivity  

Microsoft Academic Search

Increasing atmospheric CO2 will likely affect both the hydrologic cycle and ecosystem productivity. Current assumptions that increasing CO2 will lead to increased ecosystem productivity and plant water use efficiency (WUE) are driving optimistic predictions of higher crop yields as well as greater availability of freshwater resources due to a decrease in evapotranspiration. The plant physiological response that drives these effects

I. Gelfand; S. K. Hamilton; G. P. Robertson

2009-01-01

346

Agents in Decentralised Information Ecosystems: The DIET Approach  

E-print Network

Agents in Decentralised Information Ecosystems: The DIET Approach P. Marrow1 *, M. Koubarakis2 , R@dfki.de, § E-mail: fva@tsc.uc3m.es Abstract The complexity of the current global information infrastructure individuals. This paper describes a multi-agent platform, DIET (Decentralised Information Ecosystem

Koubarakis, Manolis

347

Urban Ecosystem Design Bedrich Benes  

E-print Network

Urban Ecosystem Design Bedrich Benes Michel Abdul Massih Philip Jarvis Purdue University Daniel G. Aliaga Carlos A. Vanegas a) b) c) Figure 1: This example demonstrates the need for urban ecosystems and the ecosystem is chaotic with no control. The image c) shows the managed urban ecosystem that has areas

Aliaga, Daniel G.

348

Ecosystem Management Strategies Katy Ransone  

E-print Network

Ecosystem Management Strategies Katy Ransone Biol 379- Dr. Dever 11/14/13 How we should manage as ecosystem management. The term 'ecosystem' is one that is somewhat loosely defined. In general, it includes all of the biotic (living) and abiotic (non-living) factors in a specified area. With the ecosystem

Dever, Jennifer A.

349

Linking the Response of Annual Grasslands to Warming and Altered Rainfall Across Scales of Gene Expression, Species, and Ecosystem  

NASA Astrophysics Data System (ADS)

Climate change can influence terrestrial ecosystems at multiple biological levels: gene expression, species, and ecosystem. We are studying California grassland mesocosms with seven annual species (five grasses, two forbs) that were started in 2005. In the 2006-2007 growing season, they were exposed to three rainfall treatments (297, 552, and 867 mm y-1) and soil and air temperature (ambient and elevated +4oC) in replicated greenhouses. This presentation will combine plant and ecosystem level results with transcript level analyses associated with key enzymes, such as rubisco and glutamine synthetase (GS). Because rainfall is the dominant climate variable for most processes in this Mediterranean ecosystem, the effect of warming was strongly mediated by rainfall. In fact, we saw significant interactions between temperature and rainfall treatments at all three biological levels. For example, at the ecosystem level, warming led to a decrease in aboveground and total NPP under low rainfall, and an increase under high rainfall. For the dominant species, Avena barbata, warming had no effect under high rainfall, but suppressed Avena NPP in low rainfall. At the same time, warmer, wetter conditions accelerated Avena flowering by almost 15 days. This shift in phenology was presaged by observations at the transcript level. Specifically, in the high temperature, high rainfall treatment, the levels of mRNAs for RbcS and GS2 (encoding the small subunit of rubisco and the chloroplastic isoform of GS, respectively) declined while GS1 (encoding the cytosolic isoform of GS) was upregulated several weeks before heading. The transcript level response (along with soil and plant nitrogen data) indicated the leaf had switched from a carbon and nitrogen sink to a source - consistent with more mature plant function and earlier flowering. Soil CO2 respiration also showed strong rain-by-temperature interactions that were due mainly to changes in root response (respiration and/or exudates) rather than in microbial respiration. Overall, the pervasive rain-by-temperature interactions mean that it may be very difficult to predict the effect of warming alone, without accounting for changes in precipitation (in our Mediterranean system). While predictions of warming of 3-6C in the next 100 years are fairly certain, changes in precipitation are much more uncertain, with some forecasts drier and others wetter for a given location. We suggest that uncertainty about future precipitation and the interacting influences of temperature and moisture on ecosystems are currently key limitations in predicting ecosystem response to climate change, particularly in Mediterranean ecosystems such as the one studied here.

Torn, M. S.; Bernard, S. M.; Castanha, C.; Fischer, M. L.; Hopkins, F. M.; Placella, S. A.; St. Clair, S. B.; Salve, R.; Sudderth, E.; Herman, D.; Ackerly, D.; Firestone, M. K.

2007-12-01

350

Arnold Schwarzenegger CALIFORNIA OCEAN WAVE  

E-print Network

Arnold Schwarzenegger Governor CALIFORNIA OCEAN WAVE ENERGY ASSESSMENT Prepared For: California this report as follows: Previsic, Mirko. 2006. California Ocean Wave Energy Assessment. California Energy Systems Integration · Transportation California Ocean Wave Energy Assessment is the final report

351

California's electricity crisis  

E-print Network

The collapse of California's electricity restructuring and competition program has attracted attention around the world. Prices in California's competitive wholesale electricity market increased by 500% between the second ...

Joskow, Paul L.

2001-01-01

352

Insect pest management in forest ecosystems  

NASA Astrophysics Data System (ADS)

Understanding the role of insects in forest ecosystems is vital to the development of environmentally and economically sound pest management strategies in forestry Most of the research on forest insects has been confined to phytophagous species associated with economically important tree species The roles of most other insects in forest environments have generally been ignored, including the natural enemies and associates of phytophagous species identified as being important In the past few years several investigations have begun to reevaluate the role of phytophagous species responsible for perturbation in forest ecosystems, and it appears that these species may be playing an important role in the primary productivity of those ecosystems Also, there is an increasing awareness that forest pest managers have been treating the symptoms and not the causes of the problems in the forest Many insect problems are associated with poor sites or sites where trees are growing poorly because of crowding As a result, there is considerable emphasis on the hazard rating of stands of trees for their susceptibility to various phytophagous insects The next step is to manipulate forest stands to make them less susceptible to forest pest complexes A thinning study in California is used as an example and shows that tree mortality in ponderosa pine ( Pinus ponderosa) attributable to the western pine beetle ( Dendroctonus brevicomis) can be reduced by commercial thinning to reduce stocking

Dahlsten, Donald L.; Rowney, David L.

1983-01-01

353

California Tsunami Policy Working Group  

NASA Astrophysics Data System (ADS)

California has established a Tsunami Policy Working Group of specialists from government and industry, from diverse fields including tsunami, seismic, and flood hazards, local and regional planning, structural engineering, natural hazard policy, and coastal engineering that have come together to facilitate the development of policy recommendations for tsunami hazard mitigation. The group is acting on findings from two major efforts: the USGS SAFRR (Science Application for Risk Reduction) Project - Tsunami Scenario, a comprehensive impact analysis of a large credible tsunami originating from a M 9.0 earthquake on the Aleutian Islands striking California's Coastline, and the State's Tsunami Hazard Mitigation and Education Program carried out by the California Emergency Management Agency and the California Geological Survey. The latter program is currently involved with several projects to help coastal communities reduce their tsunami risk, including two pilot projects (Crescent City in Del Norte County and the City of Huntington Beach in Orange County) where tsunami risk is among the highest in California, and a third pilot study focusing on the maritime community. The pilot projects are developing and testing probabilistic tsunami hazard products that will assist land-use and construction decisions for coastal development. The role of the policy group is to identify gaps and issues in current tsunami hazard mitigation, make recommendations that will help eliminate these impediments and to provide advice that will assist in the development and implementation of effective tsunami hazard products that will help coastal communities improve tsunami resiliency.

Real, C. R.; Johnson, L. A.

2012-12-01

354

Assessing the combined effect of dams and climate warming on streamflow in California's Sierra Nevada for regional-scale adaptation  

NASA Astrophysics Data System (ADS)

Dams and their operations harm river ecosystems, in part by altering the natural flow regimes that those ecosystems depend on. In the multi-reservoir water management systems of California's Sierra Nevada, greater emphasis is being placed on re-operating existing reservoir systems to recover downstream ecosystems. However, climate change is changing inflow patterns, affecting both ecosystems and traditional water system benefits across the region. As new reservoir operation schemes will be needed to manage for natural resources management objectives at the regional scale, characterizing historical and future environmental impacts of current operations across the region can aid in prioritizing planning efforts. We used a coarse-scale water resources simulation model developed for the western Sierra Nevada to explore the independent and combined effects of dams and climate warming on the flow regime directly below reservoirs, the focal point for instream flow requirements in operations licenses. We quantified changes to mean annual flow, annual low flow duration, annual runoff centroid timing, and weekly rate of decrease under binary combinations of management (unregulated/regulated) and climate (historical/future) conditions. We demonstrate that although rivers in the Sierra Nevada are currently managed in ways that are harmful to instream ecosystems, and that streamflow effects of operations are typically much worse than climate change effects, there are signals that reservoirs can potentially be used to help adapt to some of climate changes harmful effects with little additional effort in some cases. This study is the first step toward a better understanding of the environmental costs from and opportunities afforded by the current stock of reservoirs in a large hydroregion under changing social and environmental conditions.

Rheinheimer, D. E.; Viers, J. H.

2012-12-01

355

Ecological Signatures of Anthropogenically Altered Tidal Exchange in Estuarine Ecosystems  

Microsoft Academic Search

One of the most conspicuous anthropogenic disturbances to estuaries worldwide has been the alteration of freshwater and tidal\\u000a influence through the construction of water control structures (dikes, tide gates, culverts). Few studies have rigorously\\u000a compared the responses of differing groups of organisms that serve as contrasting conservation targets to such anthropogenic\\u000a disturbances in estuarine ecosystems. Elkhorn Slough in central California

Amy F. Ritter; Kerstin Wasson; Steve I. Lonhart; Rikke K. Preisler; Andrea Woolfolk; Katie A. Griffith; Sarah Connors; Kimberly W. Heiman

2008-01-01

356

The California School Psychologist, 1999.  

ERIC Educational Resources Information Center

This publication of the California Association of School Psychologists includes articles written by practitioners, trainers, and students. The topics represent a sampling of the broad range of students that school psychologists are asked to serve today. Two articles discuss current findings relevant to working with the populations of students who

Wilson, Marilyn, Ed.

1999-01-01

357

The California School Psychologist, 2001.  

ERIC Educational Resources Information Center

This volume of the journal for the California Association of School Psychologists provides current information on a broad array of topics related to the work of school psychologists. The articles contribute important information on contemporary issues in the field, such as using a strength-based perspective when assessing students, student support

Jimerson, Shane R., Ed.; Wilson, Marilyn, Ed.

2001-01-01

358

The California School Psychologist, 2002.  

ERIC Educational Resources Information Center

This volume of the journal for the California Association of School Psychologists provides current information on a broad array of topics related to the work of school psychologists. Articles in this volume provide information addressing an assortment of important issues in the field, including: the translations and validation of an assessment for

Jimerson, Shane R., Ed.

2002-01-01

359

The California School Psychologist, 2000.  

ERIC Educational Resources Information Center

This publication of the California Association of School Psychologists reflects a broad array of topics for those who serve a diverse group of students with a range of needs. The articles in this volume address several current topics, including cognitive assessment with bilingual students; cultural considerations when working with parents;

Jimerson, Shane R., Ed.; Wilson, Marilyn, Ed.

2000-01-01

360

CALIFORNIA ENERGY California Outdoor Lighting Baseline  

E-print Network

CALIFORNIA ENERGY COMMISSION California Outdoor Lighting Baseline Database California Outdoor Lighting Analysis Database (product 7.6.5) TECHNICALREPORT Octoberr 2003 500-03-082-A-33 Gray Davis;#12;ACKNOWLEDGEMENTS The products and outcomes presented in this report are part of the Outdoor Lighting Baseline

361

Soil community structure and ecosystem C cycling in arid ecosystems experiencing multiple environmental changes  

NASA Astrophysics Data System (ADS)

Despite the importance of soil carbon cycling to the response of water-limited ecosystems to global change, our understanding of this ecosystem component is still in its infancy. Adding to the complexity in knowledge building, ecosystems are exposed to simultaneous multiple shifts within global change scenarios. For example, semiarid grasslands in southern Arizona are currently undergoing encroachment by woody plants at the same time that climate change models predict increases in frequency and magnitude of precipitation inputs over the next 50 years. We are investigating how heterogeneity of plant cover mediates the response of soil community structure and ecosystem C cycling to seasonal monsoon rain inputs. Field plots were established in a mesquite shrubland in the San Pedro River Basin, AZ that are dominated by either: Sporobulus wrightii, medium sized Prosopis velutina, or large Prosopis velutina, additional plots were located in intercanopy areas. Both increased quantity and quality of litter inputs to the soil component, and physical influences of the shrubs on ecosystem water and energy budgets affects plots influenced by the development of Prosopis. Plant species influenced the response of soil microbial biomass to precipitation pulses. Plant cover also influenced the dynamics of soil nematodes. Magnitude of precipitation inputs and plant cover interact to affect the abundance of trophic group abundances and food web structure. These results will be discussed vis--vis the importance of soil organisms for driving ecosystem dynamics, and the appropriateness of dominant paradigms in arid land ecology (notably the pulse-reserve paradigm) for understanding soil components of arid ecosystems. Shifts in soil flora and fauna have important implications for ecosystem C-cycling via alterations of trophic dynamics, and the contribution of heterotrophic respiration to C efflux from ecosystems.

Pavao-Zuckerman, M. A.; Cable, J. M.; Huxman, T. E.; Scott, R. L.; Williams, D. G.

2005-12-01

362

Vulnerability and resilience of European ecosystems towards extreme climatic events: The ecosystem perspective  

NASA Astrophysics Data System (ADS)

Extremes of meteorological events may but do not have to cause damages in ecosystems. Climate change is expected to have a strong impact on the resilience and stability of ecosystems worldwide. So far, the impacts of trends and extremes of physical drivers on ecosystems have generally been studied regardless of the extremeness of the ecosystem response. We base our analysis on a Probabilistic Risk Assessment concept of Van Oijen et al. (2013) quantifying the vulnerability of vegetation dynamics in relation to the extremeness of meteorological drivers such as temperature, precipitation or drought indices. Here, the definition of extreme, hazardous weather conditions is based on the ecosystem response. Instead of searching for extreme meteorological events, we define extreme ecosystem responses in terms of threshold levels of carbon uptake, and search for the meteorological conditions which are responsible. Having defined hazardous events in this way, we quantify the vulnerability or resilience of ecosystems to such hazards. We apply this approach on results of different vegetation models (such as LPJmL, Orchidee, JSBACH or CLM4) and the forest model BASFOR using climatic input for Europe from the WATCH-ERAI-REMO climate dataset with the SRES A1B emission scenario. Our results show that under current climatic conditions, the southern part of Europe already suffers severe heat and drought stress which is reflected in our approach by vulnerability values being high for precipitation, relatively high for the SPEI index, moderately high for temperature and quite high for the consecutive dry days. Thus, hazard occurrence is frequent enough to determine ecosystem vulnerability but this depends on the definition of the threshold of hazardous ecosystem responses. Vulnerability values in the Mediterranean increase towards the end of the 21st century for all models indicating that a tipping point towards drought damages has been reached for the chosen climate scenario.

Thonicke, Kirsten; Rolinski, Susanne; Walz, Ariane; von Bloh, Werner; van Oijen, Marcel; Davin, Edouard; Vieli, Barla; Kato, Tomomichi; Beer, Christian

2014-05-01

363

Estimating the vulnerability of European ecosystems to extreme events: The ecosystem perspective  

NASA Astrophysics Data System (ADS)

Extremes of meteorological events may but do not have to cause damages in ecosystems. Climate change is expected to have a strong impact on the productivity and stability of ecosystems worldwide. So far, the impacts of extreme drivers on ecosystems have generally been studied regardless of the extremeness of the ecosystem response. We base our analysis on a Probabilistic Risk Assessment concept of Van Oijen et al. quantifying the vulnerability of vegetation dynamics in relation to the extremeness of meteorological drivers such as temperature or precipitation. Here, the definition of extreme, hazardous weather conditions is based on the ecosystem response. Hence, instead of searching for extreme meteorological events, we define extreme ecosystem responses in terms of threshold levels of carbon uptake, and search for the meteorological conditions responsible. Having defined hazardous events in this way, we quantify the vulnerability of ecosystems to the such hazards. We apply this approach on results of the dynamic process-based vegetation model LPJmL using climatic input for Europe from the WATCH-ERAI-REMO climate scenario with the SRES A1B emission scenario. Our results show that under current climatic conditions, the southern part of Europe already suffers severe heat and drought stress which is reflected in our approach by vulnerability values being high for precipitation, relatively high for the SPEI index, moderately high for temperature and quite high for the consecutive dry days. Thus, hazard occurrence is frequent enough to determine ecosystem vulnerability but this depends on the definition of the threshold of hazardous ecosystem responses.

Rolinski, Susanne; Thonicke, Kirsten; Rammig, Anja; Walz, Ariane; van Oijen, Marcel

2013-04-01

364

STATE OF CALIFORNIA THE RESOURCES AGENCY ARNOLD SCHWARZENEGGER, Governor CALIFORNIA ENERGY COMMISSION  

E-print Network

STATE OF CALIFORNIA ­ THE RESOURCES AGENCY ARNOLD SCHWARZENEGGER, Governor CALIFORNIA ENERGY COMMISSION 1516 NINTH STREET SACRAMENTO, CA 95814-5512 www.energy.ca.gov TO: All Parties RE: Orange Grove for the above-mentioned project, current as of October 27, 2008. The new addition(s) to the Proof of Service

365

STATE OF CALIFORNIA THE RESOURCES AGENCY ARNOLD SCHWARZENEGGER, Governor CALIFORNIA ENERGY COMMISSION  

E-print Network

STATE OF CALIFORNIA THE RESOURCES AGENCY ARNOLD SCHWARZENEGGER, Governor CALIFORNIA ENERGY of Regulations, section 1769). Energy Commission staff is currently analyzing the request and will publish COMMISSION 1516 NINTH STREET SACRAMENTO, CA 95814-5512 NOTICE OF RECEIPT PETITION TO AMEND THE ENERGY

366

STATE OF CALIFORNIA THE RESOURCES AGENCY ARNOLD SCHWARZENEGGER, Governor CALIFORNIA ENERGY COMMISSION  

E-print Network

STATE OF CALIFORNIA THE RESOURCES AGENCY ARNOLD SCHWARZENEGGER, Governor CALIFORNIA ENERGY). Energy Commission staff is currently analyzing the request and will publish an analysis in the near COMMISSION 1516 NINTH STREET SACRAMENTO, CA 95814-5512 NOTICE OF RECEIPT PETITION TO AMEND THE ENERGY

367

Sea ice ecosystems.  

PubMed

Polar sea ice is one of the largest ecosystems on Earth. The liquid brine fraction of the ice matrix is home to a diverse array of organisms, ranging from tiny archaea to larger fish and invertebrates. These organisms can tolerate high brine salinity and low temperature but do best when conditions are milder. Thriving ice algal communities, generally dominated by diatoms, live at the ice/water interface and in recently flooded surface and interior layers, especially during spring, when temperatures begin to rise. Although protists dominate the sea ice biomass, heterotrophic bacteria are also abundant. The sea ice ecosystem provides food for a host of animals, with crustaceans being the most conspicuous. Uneaten organic matter from the ice sinks through the water column and feeds benthic ecosystems. As sea ice extent declines, ice algae likely contribute a shrinking fraction of the total amount of organic matter produced in polar waters. PMID:24015900

Arrigo, Kevin R

2014-01-01

368

Motivations for the Restoration of Ecosystems ANDRE F. CLEWELL  

E-print Network

five rationales: technocratic, biotic, heuristic, idealistic, and pragmatic. The technocratic rationale caused by ecosystem loss. We propose that technocratic restoration, as currently conceived and practiced importance is just beginning to be recognized. We sug- gest that technocratic restoration is too

Rey Benayas, José María

369

CLIMATE CHANGE AND ECOSYSTEMS OF THE MID-ATLANTIC REGION  

EPA Science Inventory

This paper discusses the current status of forested, wetland, freshwater and coastal ecosystems; the combined impacts of habitat alteration, pollution and non-native invasive species on those systems; how climatic changes could interact with existing stresses; potential managemen...

370

An E-learning Ecosystem Based on Cloud Computing Infrastructure Bo Dong1, 2  

E-print Network

An E-learning Ecosystem Based on Cloud Computing Infrastructure Bo Dong1, 2 , Qinghua Zheng1, 2 that an e-learning ecosystem is the next generation e- learning. However, the current models of e-learning computation and storage resources for e- learning ecosystems. Cloud computing is a promising infrastructure

Li, Haifei

371

A Binary Approach to Define and Classify Final Ecosystem Goods and Services  

EPA Science Inventory

The ecosystem services literature decries the lack of consistency and standards in the application of ecosystem services as well as the inability of current approaches to explicitly link ecosystem services to human well-being. Recently, SEEA and CICES have conceptually identifie...

372

The Decline of Amphibians in California's Great Central Valley  

Microsoft Academic Search

Declines in amphibian populations are rarely reported on the community or ecosystem level. We combined broad-scale field sampling with historical analyses of museum records to quantify amphibian de- clines in California's Great Central Valley. Overall, amphibians showed an unambiguous pattern of decline, although the intensity of decline varied both geographically and taxonomically. The greatest geographical de- cline was detected in

Robert N. Fisher; H. Bradley Shaffer

1996-01-01

373

Climate Change and California Water Management John T. Andrew  

E-print Network

in increased flood control demand on reservoir space Higher water temperatures impacts ecosystem Sea level riseClimate Change and California Water Management John T. Andrew First Western Forum on Energy & Water Todd Russell Yaworsky (USBR) Hongbing Yin www.baydeltaoffice.water.ca.gov/ climatechange.cfm #12

Keller, Arturo A.

374

Biodiversity of Mycorrhizal Fungi in Southern California1  

E-print Network

Biodiversity of Mycorrhizal Fungi in Southern California1 Michael F. Allen2 , Louise Egerton Harney, and Thomas Zink Abstract Mycorrhizal fungi are a diverse group of organisms and form an integral as indicators of changing ecosystem dynamics. There are probably more than a hundred mycorrhizal fungi

Standiford, Richard B.

375

NUCLEAR POWER in CALIFORNIA  

E-print Network

NUCLEAR POWER in CALIFORNIA: 2007 STATUS REPORT CALIFORNIA ENERGY COMMISSION October 2007 CEC-100 public workshops on nuclear power. The Integrated Energy Policy Report Committee, led by Commissioners, California Contract No. 700-05-002 Prepared For: California Energy Commission Barbara Byron, Senior Nuclear

376

California's Water Energy Relationship  

E-print Network

1 CALIFORNIA ENERGY COMMISSION California's Water ­ Energy Relationship Prepared in Support The California's Water-Energy Relationship report is the product of contributions by many California Energy, Lorraine White and Zhiqin Zhang. Staff would also like to thank the members of the Water-Energy Working

377

Invasion, competitive dominance, and resource use by exotic and native California grassland species.  

PubMed

The dynamics of invasive species may depend on their abilities to compete for resources and exploit disturbances relative to the abilities of native species. We test this hypothesis and explore its implications for the restoration of native ecosystems in one of the most dramatic ecological invasions worldwide, the replacement of native perennial grasses by exotic annual grasses and forbs in 9.2 million hectares of California grasslands. The long-term persistence of these exotic annuals has been thought to imply that the exotics are superior competitors. However, seed-addition experiments in a southern California grassland revealed that native perennial species, which had lower requirements for deep soil water, soil nitrate, and light, were strong competitors, and they markedly depressed the abundance and fecundity of exotic annuals after overcoming recruitment limitations. Native species reinvaded exotic grasslands across experimentally imposed nitrogen, water, and disturbance gradients. Thus, exotic annuals are not superior competitors but rather may dominate because of prior disturbance and the low dispersal abilities and extreme current rarity of native perennials. If our results prove to be general, it may be feasible to restore native California grassland flora to at least parts of its former range. PMID:14595028

Seabloom, Eric W; Harpole, W Stanley; Reichman, O J; Tilman, David

2003-11-11

378

Invasion, competitive dominance, and resource use by exotic and native California grassland species  

PubMed Central

The dynamics of invasive species may depend on their abilities to compete for resources and exploit disturbances relative to the abilities of native species. We test this hypothesis and explore its implications for the restoration of native ecosystems in one of the most dramatic ecological invasions worldwide, the replacement of native perennial grasses by exotic annual grasses and forbs in 9.2 million hectares of California grasslands. The long-term persistence of these exotic annuals has been thought to imply that the exotics are superior competitors. However, seed-addition experiments in a southern California grassland revealed that native perennial species, which had lower requirements for deep soil water, soil nitrate, and light, were strong competitors, and they markedly depressed the abundance and fecundity of exotic annuals after overcoming recruitment limitations. Native species reinvaded exotic grasslands across experimentally imposed nitrogen, water, and disturbance gradients. Thus, exotic annuals are not superior competitors but rather may dominate because of prior disturbance and the low dispersal abilities and extreme current rarity of native perennials. If our results prove to be general, it may be feasible to restore native California grassland flora to at least parts of its former range. PMID:14595028

Seabloom, Eric W.; Harpole, W. Stanley; Reichman, O. J.; Tilman, David

2003-01-01

379

Grays Lake Ecosystem  

NSDL National Science Digital Library

This case study looks at the marsh ecosystem of Grays Lake in southeast Idaho, and is hosted by the Northern Prairie Wildlife Research Center (NPWRC). Grays Lake has been the focus of numerous research studies to understand factors affecting breeding water birds, habitat management practices, populations, and geological factors. This report gives general information about the Grays Lake ecosystem, including climate, habitats, plant communities, wildlife, water, and geology. More specific details are given through flora and fauna lists, historical and cultural overviews, details about the Grays Lake National Wildlife Refuge, and research information on management of wetlands.

380

Using seabird habitat modeling to inform marine spatial planning in central California's National Marine Sanctuaries.  

PubMed

Understanding seabird habitat preferences is critical to future wildlife conservation and threat mitigation in California. The objective of this study was to investigate drivers of seabird habitat selection within the Gulf of the Farallones and Cordell Bank National Marine Sanctuaries to identify areas for targeted conservation planning. We used seabird abundance data collected by the Applied California Current Ecosystem Studies Program (ACCESS) from 2004-2011. We used zero-inflated negative binomial regression to model species abundance and distribution as a function of near surface ocean water properties, distances to geographic features and oceanographic climate indices to identify patterns in foraging habitat selection. We evaluated seasonal, inter-annual and species-specific variability of at-sea distributions for the five most abundant seabirds nesting on the Farallon Islands: western gull (Larus occidentalis), common murre (Uria aalge), Cassin's auklet (Ptychorampus aleuticus), rhinoceros auklet (Cerorhinca monocerata) and Brandt's cormorant (Phalacrocorax penicillatus). The waters in the vicinity of Cordell Bank and the continental shelf east of the Farallon Islands emerged as persistent and highly selected foraging areas across all species. Further, we conducted a spatial prioritization exercise to optimize seabird conservation areas with and without considering impacts of current human activities. We explored three conservation scenarios where 10, 30 and 50 percent of highly selected, species-specific foraging areas would be conserved. We compared and contrasted results in relation to existing marine protected areas (MPAs) and the future alternative energy footprint identified by the California Ocean Uses Atlas. Our results show that the majority of highly selected seabird habitat lies outside of state MPAs where threats from shipping, oil spills, and offshore energy development remain. This analysis accentuates the need for innovative marine spatial planning efforts and provides a foundation on which to build more comprehensive zoning and management in California's National Marine Sanctuaries. PMID:23967206

McGowan, Jennifer; Hines, Ellen; Elliott, Meredith; Howar, Julie; Dransfield, Andrea; Nur, Nadav; Jahncke, Jaime

2013-01-01

381

Plant-soil biodiversity relationships and nutrient retention in agricultural riparian zones of the Sacramento Valley, California  

Microsoft Academic Search

Forested riparian buffers in California historically supported high levels of biodiversity, but human activities have degraded\\u000a these ecosystems over much of their former range. This study examined plant communities, belowground biodiversity and indicators\\u000a of multiple ecosystem functions of riparian areas across an agricultural landscape in the Sacramento Valley of California,\\u000a USA. Plant, nematode and soil microbial communities and soil physical

Anna Young-MathewsSteven; Steven W. Culman; Sara Snchez-Moreno; A. Toby OGeen; Howard Ferris; Allan D. Hollander; Louise E. Jackson

2010-01-01

382

Animals as indicators of ecosystem responses to air emissions  

NASA Astrophysics Data System (ADS)

With existing and proposed air-quality regulations, ecological disasters resulting from air emissions such as those observed at Copperhill, Tennessee, and Sudbury, Ontario, are unlikely. Current air-quality standards, however, may not protect ecosystems from subacute and chronic exposure to air emissions. The encouragement of the use of coal for energy production and the development of the fossil-fuel industries, including oil shales, tar sands, and coal liquification, point to an increase and spread of fossil-fuel emissions and the potential to influence a number of natural ecosystems. This paper reviews the reported responses of ecosystems to air-borne pollutants and discusses the use of animals as indicators of ecosystem responses to these pollutants. Animal species and populations can act as important indicators of biotic and abiotic responses of aquatic and terrestrial ecosystems. These responses can indicate long-term trends in ecosystem health and productivity, chemical cycling, genetics, and regulation. For short-term trends, fish and wildlife also serve as monitors of changes in community structure, signaling food-web contamination, as well as providing a measure of ecosystem vitality. Information is presented to show not only the importance of animals as indicators of ecosystem responses to air-quality degradation, but also their value as air-pollution indices, that is, as air-quality-related values (AQRV), required in current air-pollution regulation.

Newman, James R.; Schreiber, R. Kent

1984-07-01

383

Ecosystem approach to management I. "dynamic" ecosystem management v.  

E-print Network

parts of it, ecosystem structure and function is the focus of management Considers the effects = long term Ecosystem management Considers humans and all living components as one interacting system of the community #12;4 Sustainable management at an ecosystem level will only succeed when human welfare

Dever, Jennifer A.

384

Enabling the Integrated Assessment of Large Marine Ecosystems: Informatics to the Forefront of Science-Based Decision Support  

NASA Astrophysics Data System (ADS)

Integrated assessments of large marine ecosystems require the understanding of interactions between environmental, ecological, and socio-economic factors that affect production and utilization of marine natural resources. Assessing the functioning of complex coupled natural-human systems calls for collaboration between natural and social scientists across disciplinary and national boundaries. We are developing a platform to implement and sustain informatics solutions for these applications, providing interoperability among very diverse and heterogeneous data and information sources, as well as multi-disciplinary organizations and people. We have partnered with NOAA NMFS scientists to facilitate the deployment of an integrated ecosystem approach to management in the Northeast U.S. (NES) and California Current Large Marine Ecosystems (LMEs). Our platform will facilitate the collaboration and knowledge sharing among NMFS natural and social scientists, promoting community participation in integrating data, models, and knowledge. Here, we present collaborative software tools developed to aid the production of the Ecosystem Status Report (ESR) for the NES LME. The ESR addresses the D-P-S portion of the DPSIR (Driver-Pressure-State-Impact-Response) management framework: reporting data, indicators, and information products for climate drivers, physical and human (fisheries) pressures, and ecosystem state (primary and secondary production and higher trophic levels). We are developing our tools in open-source software, with the main tool based on a web application capable of providing the ability to work on multiple data types from a variety of sources, providing an effective way to share the source code used to generate data products and associated metadata as well as track workflow provenance to allow in the reproducibility of a data product. Our platform retrieves data, conducts standard analyses, reports data quality and other standardized metadata, provides iterative and interactive visualization, and enables the download of data plotted in the ESR. Data, indicators, and information products include time series, geographic maps, and uni-variate and multi-variate analyses. Also central to the success of this initiative is the commitment to accommodate and train scientists of multiple disciplines who will learn to interact effectively with this new integrated and interoperable ecosystem assessment capability. Traceability, repeatability, explanation, verification, and validation of data, indicators, and information products are important for cross-disciplinary understanding and sharing with managers, policymakers, and the public. We are also developing an ontology to support the implementation of the DPSIR framework. These new capabilities will serve as the essential foundation for the formal synthesis and quantitative analysis of information on relevant natural and socio-economic factors in relation to specified ecosystem management goals which can be applied in other LMEs.

Di Stefano, M.; Fox, P. A.; Beaulieu, S. E.; Maffei, A. R.; West, P.; Hare, J. A.

2012-12-01

385

Shelf-sea ecosystems  

SciTech Connect

An analysis of the food chain dynamics of the Oregon, Alaskan, and New York shelves is made with respect to differences in physical forcing of these ecosystems. The world's shelves are 10% of the area of the ocean, yield 99% of the world's fish catch, and may be a major sink in the global CO/sub 2/ budget.

Walsh, J J

1980-01-01

386

DECOMPOSITION IN FRESHWATER ECOSYSTEMS  

Microsoft Academic Search

This review examines the sources and composition of organic matter and the decomposition of particulate and dissolved organic matter (POM and DOM) in freshwater ecosystems. The main points to emerge from the review are listed below.1. Terrestrial plant material is an important source of allochthonous POM in lotlc systems.2. In lentic systems important autochthonous sources of DOM are the algae

R. D. Robarts

1986-01-01

387

Effects on aquatic ecosystems  

Microsoft Academic Search

Regarding the effects of UV-B radiation on aquatic ecosystems, recent scientific and public interest has focused on marine primary producers and on the aquatic web, which has resulted in a multitude of studies indicating mostly detrimental effects of UV-B radiation on aquatic organisms. The interest has expanded to include ecologically significant groups and major biomass producers using mesocosm studies, emphasizing

D.-P. Hder; H. D. Kumar; R. C. Smith; R. C. Worrest

1998-01-01

388

The Global Ecosystem  

NSDL National Science Digital Library

This site contains 11 questions on the topic of ecosystems, which covers food chains and organism characteristics. This is part of the Principles of Earth Science course at the University of South Dakota. Users submit an answer and are provided immediate verification.

Heaton, Timothy

389

TERRESTRIAL ECOSYSTEM SIMULATOR  

EPA Science Inventory

The Terrestrial Habitats Project at the Western Ecology Division (Corvallis, OR) is developing tools and databases to meet the needs of Program Office clients for assessing risks to wildlife and terrestrial ecosystems. Because habitat is a dynamic condition in real-world environm...

390

Ecosystem Restoration Research at GWERD  

EPA Science Inventory

Ground Water and Ecosystems Restoration Division, Ada, OK Mission: Conduct research and technical assistance to provide the scientific basis to support the development of strategies and technologies to protect and restore ground water, surface water, and ecosystems impacted b...

391

Introduction Ecosystem management has been  

E-print Network

65(2) 1 Introduction Ecosystem management has been vigorously debated at many meetings, conferences, and workshops (Inter- agency Ecosystem Management Task Force, 1995; Malone, 1995; Stanley, 1995; Christensen et

392

Leaders for California's Schools. Policy Brief 09-4  

ERIC Educational Resources Information Center

In this policy brief the authors present an overview of the current state of school leadership in California. They examine the challenges that California must overcome to recruit, hire, train, and retain strong and talented principals, with a particular focus on the limitations of current state and district policies. They also propose a set of

Loeb, Susanna; Valant, Jon

2009-01-01

393

Southern California Edison's Evaluation of California Energy Commission  

E-print Network

, 2008), which is the joint product of the Southern California Earthquake Center (SCECSouthern California Edison's Evaluation of California Energy Commission AB 1632 Report REPORT Prepared for Southern California Edison December 2010 #12;SAN ONOFRE NUCLEAR

394

Teaching about Ecosystems. ERIC Digest.  

ERIC Educational Resources Information Center

Ecosystems are available to educators as interactive units and as such the National Science Education Standards (NSES) and the Excellence in Environmental Education: Guidelines for Learning (EEE) put considerable emphasis on ecosystems. This ERIC Digest describes the NSES and EEE guidelines for grades 5-8 and 9-12 to provide a basic ecosystem

Haury, David L.

395

Antarctica: A Cold Desert Ecosystem  

NSDL National Science Digital Library

This Antarctica lesson has students locate the continent on a globe and on a map, describe and illustrate major Antarctic ecosystems, and explain relationships between those ecosystems. They will also construct a rough map of Antarctic ecosystems and explore relationships among the creatures that populate them. This lesson can be adapted to focus on other regions, including the one in which students live.

396

Investigating Ecosystems in a Biobottle  

ERIC Educational Resources Information Center

Biobottles are miniature ecosystems made from 2-liter plastic soda bottles. They allow students to explore how organisms in an ecosystem are connected to each other, examine how biotic and abiotic factors influence plant and animal growth and development, and discover how important biodiversity is to an ecosystem. This activity was inspired by an

Breene, Arnica; Gilewski, Donna

2008-01-01

397

Evolution of Continental Aquatic Ecosystems  

Microsoft Academic Search

Ecosystem evolution still remains the least under- stood part of evolutionary theory. Discussions of eco- system evolution almost inevitably digress to biotic components, often to a single group of organisms. Cer- tainly, biotic components evolve with ecosystems, but the focus should not be displaced from ecosystem char- acters as such, the trophic and, more generally speak- ing, the information links

A. G. Ponomarenko

1996-01-01

398

Ecosystem services and water economics  

E-print Network

Ecosystem services and water economics Florida Agricultural Commodity & Policy Outlook Conference, Food & Resource Economics Department, University of Florida/IFAS · Part II. Markets for Ecosystem preferences o Technological changes o Market competition o Recent: · Water availability · Ecosystem service

Hill, Jeffrey E.

399

Ecosystem Task Force Meeting Minutes  

E-print Network

Ecosystem Task Force Meeting Minutes Date: April 28, 2011 Title of Meeting: Monthly Meeting. A focus on planning helps ground the Task Force because of the complexity of ecosystems. UNH-862-0785 sustainability.info@unh.edu http://www.sustainableunh.unh.edu/ #12;3.1. Ecosystem work has no defined parameters

New Hampshire, University of

400

1, 275309, 2004 Net ecosystem  

E-print Network

BGD 1, 275­309, 2004 Net ecosystem exchange of carbondioxide and water A. J. Dolman et al. Title Discussions Biogeosciences Discussions is the access reviewed discussion forum of Biogeosciences Net ecosystem.dolman@geo.falw.vu.nl) 275 #12;BGD 1, 275­309, 2004 Net ecosystem exchange of carbondioxide and water A. J. Dolman et al

Paris-Sud XI, Université de

401

[Advances in energy analysis of agro-ecosystems].  

PubMed

The energy analysis of agro-ecosystems from the view point of energy flow is a quantitative study on the function of agro-ecosystem, and is one of the most important aspects in agro-ecosystem study. In this paper, the history and some current progresses of energy analysis on agro-ecosystems were reviewed briefly, and the difference and breakthrough of emergy analysis theory with the traditional energy analysis method, some current challenges in front of emergy analysis of agro-ecosystems, and some of the new trends were discussed. Using the direct and indirect cost of solar energy to evaluate any energy or material, emergy analysis is the new development of energy analysis, not only in concept but also on calculation method. Developing to emergy analysis phase, there were still some deficiencies on energy analysis of agro-ecosystem, such as the complicate calculation of transformation and the vacancy of energy index for sustainable development, etc. How to solve these problems combined with the clearing of the maximum Em-power principle, the combination among energy analysis, emergy analysis, material analysis and landscape analysis has made up of the current and future trends of energy analysis of agro-ecosystem. PMID:15139211

Lu, Hongfang; Lan, Shengfang; Chen, Feipeng; Peng, Shaolin

2004-01-01

402

Utilizing Ecosystem Information to Improve Decision Support Systems for Marine Fisheries (Invited)  

NASA Astrophysics Data System (ADS)

Successful ecological forecasting of fishery yields has eluded resource managers for decades. However, recent advances in observing systems, computational power and understanding of ecosystem function offer credible evidence that the variability of the ocean ecosystem and its impact on fishery yield can be forecast accurately enough and with enough lead time to be useful to society. Advances in space-based real time sensors, high performance computing, very high-resolution physical models, and robust ecosystem theory make possible operational forecasts of both fish availability and ecosystem health. Accurate and timely forecasts can provide the information needed to maintain the long-term sustainability of fish stocks and protect the ecosystem of which the fish are an integral part, while maximizing social and economic benefits and preventing wasteful overinvestment of economic resources. Here we review progress in improving the decision support systems by forecasting two marine fisheries: 1) the coastal Peru small pelagic fishery and 2) the central California salmon fishery.

Chavez, F.; Chai, F.; Chao, Y.; Wells, B.; Safari Team

2010-12-01

403

Reconstructing past population processes with general equilibrium models: House mice in Kern County, California, 19261927  

Microsoft Academic Search

Reconstructing past ecosystem conditions is helpful in addressing a range of basic and applied questions, but difficult because of a lack of inferential or modeling approaches. Here, we demonstrate the use of a general equilibrium ecosystem model (GEEM) to investigate ecological conditions surrounding a population eruption of the house mouse (Mus musculus) in Kern County, California in the 1920s, arguably

Seong-Hee Kim; John Tschirhart; Steven W. Buskirk

2007-01-01

404

Climatology of extreme winds in southern California  

SciTech Connect

A climatology of annual extreme winds in southern California has been prepared. The climatology includes a description of extreme wind regions, defined on the basis of observed winds and topography. Extreme wind distribution parameters have been estimated for 46 locations using data obtained from the National Climatic Data Center. Probabilities associated with extreme winds have been estimated for these locations. The results of the analysis are generally consistent with previous estimates of extreme winds in southern California. Although in several instances the current estimates are significantly higher than previous estimates. The data examined do not indicate that there has been a significant change in the extreme wind climate of southern California.

Ramsdell, J.V.; Hubbe, J.M.; Elliott, D.L.; Holladay, C.G.

1987-01-01

405

California's Public Health Laboratories: Inter-organizational cooperation models to bolster laboratory capacity.  

E-print Network

??AbstractCalifornia's Public Health Laboratories: Inter-organizational cooperation models to bolster laboratory capacityBackground: California has 61 local health departments that are currently served by 37 local public (more)

Hsieh, Kristina

2011-01-01

406

Building an Ecosystem  

NSDL National Science Digital Library

This activity is designed to follow our students from grade 7 - 12. Each year adds to or builds upon previous years. The project is centered around a 400 gallon, 4 tank system which is placed in sunlight in the lobby of our science building. It was seeded with water from nearby rivers, lakes, ponds, and creeks. The only mechanical part is a pump which returns water from tank 4 back to tank 1. This aquatic ecosystem is a constant, woven through the curriculum as students progress through science. At the end of 3-5 science courses students have greater awareness of the role of detritivores and decomposers in the cycling of matter and understand how human activities may upset the balance in an ecosystem. One goal is for students to see the relationship between what is studied in a classroom and the real world; another is for them to understand the role of wetlands in making water suitable to sustain life.

BEGIN:VCARD VERSION:2.1 FN:Charlotte C. Freeman N:C. Freeman;Charlotte ORG:Girls Preparatory School REV:2005-04-08 END:VCARD

1995-06-30

407

OXIDANT AIR POLLUTANT EFFECTS ON A WESTERN CONIFEROUS FOREST ECOSYSTEM: TASK A, PLANNING CONFERENCE  

EPA Science Inventory

This is a report on a planning conference to develop a protocol for a study on the impact of oxidant air pollution from an urban area on a forest ecosystem and recreational area. The conference was held July 21-23, 1971 at the Arrowhead Conference Center in California to discuss ...

408

Fluorescence signatures applied to climate change effects: case studies with Mediterranean oak ecosystems  

Microsoft Academic Search

In Mediterranean-Type Ecosystems (MTE), the photosynthetic apparatus of plants are exposed to long summer droughts and high or low temperatures. Evergreen oak species are dominant in landscapes of countries surrounding: the Mediterranean sea plus parts of California and constitute large shrublands and woodlands. Some hypotheses have been advanced to explain their distributions and comparative advantages. Many of the major distributional

S. Rambal; M. Methy; C. Damesin

1994-01-01

409

Assessing Climate Change Impacts on Vernal Pool Ecosystems and Endemic Branchiopods  

Microsoft Academic Search

This study evaluated the hydrologic sensitivity of vernal pool ecosystems in the Central Valley of California to climatic changes projected for 2100. A vernal pool water-balance model was used to evaluate rain-fed vernal pools at four locations under future conditions projected by two contrasting global climate models. The potential for change in the duration of continuous inundation, frequency of reproductively

Christopher R. Pyke

2005-01-01

410

Global Educational Ecosystem: Case Study of a Partnership with K-12 Schools, Community Organizations, and Business  

ERIC Educational Resources Information Center

The purpose of this study was to describe a collaborative partnership model known as the Global Educational Ecosystem, which involves three K-12 schools in Northern California, community organizations (representing science, technology, health, and arts), and Xilinx, Inc. from the perspectives of the leaders of the involved partner organizations in

Lewis, Donna S.

2010-01-01

411

PHYTOPLANKTON BLOOM YNAMICS IN COASTAL ECOSYSTEMS: A REVIEW WITH SOME GENERAL LESSONS  

E-print Network

). These physical forcings have different timescales of variability, so algal blooms can be short-term episodicPHYTOPLANKTON BLOOM YNAMICS IN COASTAL ECOSYSTEMS: A REVIEW WITH SOME GENERAL LESSONS FROM, California Abstract. Phytoplankton blooms are prominent fea- tures of biological variability in shallow

412

Scientific Foundations for an IUCN Red List of Ecosystems  

PubMed Central

An understanding of risks to biodiversity is needed for planning action to slow current rates of decline and secure ecosystem services for future human use. Although the IUCN Red List criteria provide an effective assessment protocol for species, a standard global assessment of risks to higher levels of biodiversity is currently limited. In 2008, IUCN initiated development of risk assessment criteria to support a global Red List of ecosystems. We present a new conceptual model for ecosystem risk assessment founded on a synthesis of relevant ecological theories. To support the model, we review key elements of ecosystem definition and introduce the concept of ecosystem collapse, an analogue of species extinction. The model identifies four distributional and functional symptoms of ecosystem risk as a basis for assessment criteria: A) rates of decline in ecosystem distribution; B) restricted distributions with continuing declines or threats; C) rates of environmental (abiotic) degradation; and D) rates of disruption to biotic processes. A fifth criterion, E) quantitative estimates of the risk of ecosystem collapse, enables integrated assessment of multiple processes and provides a conceptual anchor for the other criteria. We present the theoretical rationale for the construction and interpretation of each criterion. The assessment protocol and threat categories mirror those of the IUCN Red List of species. A trial of the protocol on terrestrial, subterranean, freshwater and marine ecosystems from around the world shows that its concepts are workable and its outcomes are robust, that required data are available, and that results are consistent with assessments carried out by local experts and authorities. The new protocol provides a consistent, practical and theoretically grounded framework for establishing a systematic Red List of the worlds ecosystems. This will complement the Red List of species and strengthen global capacity to report on and monitor the status of biodiversity PMID:23667454

Keith, David A.; Rodriguez, Jon Paul; Rodriguez-Clark, Kathryn M.; Nicholson, Emily; Aapala, Kaisu; Alonso, Alfonso; Asmussen, Marianne; Bachman, Steven; Basset, Alberto; Barrow, Edmund G.; Benson, John S.; Bishop, Melanie J.; Bonifacio, Ronald; Brooks, Thomas M.; Burgman, Mark A.; Comer, Patrick; Comin, Francisco A.; Essl, Franz; Faber-Langendoen, Don; Fairweather, Peter G.; Holdaway, Robert J.; Jennings, Michael; Kingsford, Richard T.; Lester, Rebecca E.; Nally, Ralph Mac; McCarthy, Michael A.; Moat, Justin; Oliveira-Miranda, Maria A.; Pisanu, Phil; Poulin, Brigitte; Regan, Tracey J.; Riecken, Uwe; Spalding, Mark D.; Zambrano-Martinez, Sergio

2013-01-01

413

SFRSF: Our Coastal Ecosystems  

NSDL National Science Digital Library

This South Florida Restoration Science Forum (SFRSF) page highlights the coastal ecosystems of southern Florida. Research displayed from poster presentations covers the coastal area habitats, sustaining and enhancing coastal waters, major coastal challenges, restoring and enhancing estuaries, and using science for effective resource management. The six estuaries discussed are the Caloosahatchee, Southwest Florida, Biscayne Bay, Florida Bay, Florida Keys, and St. Lucie estuaries. Specific issues concerning each estuary are covered, and links are provided for additional information.

414

California's Green Economy  

E-print Network

California's Green Economy California Green Workforce Coalition July 9, 2010 Bonnie Graybill Employment Development Department Labor Market Information Division #12;Understanding the Green Economy What's green economy Demand leads to pressure for additional supply of products and services Survey covers

415

California Educational Research Association  

E-print Network

, California Department of Education "Transitioning to the Future: Common Core State Standards, New Assessments's efforts with implementing California's Common Core State Standards (CCSS) and the future of CCSS related

Rose, Michael R.

416

CALIFORNIA CARBON SEQUESTRATION THROUGH  

E-print Network

CALIFORNIA ENERGY COMMISSION CARBON SEQUESTRATION THROUGH CHANGES IN LAND USE IN WASHINGTON. Carbon Sequestration Through Changes in Land Use in Washington: Costs and Opportunities. California for Terrestrial Carbon Sequestration in Oregon. Report to Winrock International. #12;ii #12;iii Preface

417

CALIFORNIA ENERGY COMMISSIONGUIDEBOOK  

E-print Network

renewable energy, production incentives, renewables portfolio standard, biomass, solar thermal electricCALIFORNIA ENERGY COMMISSION COMMISSIONGUIDEBOOK EXISTING RENEWABLE FACILITIES PROGRAM FIFTH EDITION SEPTEMBER 2008 CEC-300-2008-002-CMF Arnold Schwarzenegger, Governor #12;#12;#12;CALIFORNIA ENERGY

418

California Energy Commission: Fuels.  

National Technical Information Service (NTIS)

Fuel is critical to California's economy. Consumer expenditures on fuel alone amount to $34 billion each year in California. But the contribution goes well beyond consumer expenses on the fuel itself. These fuels enable countless transactions in the marke...

1999-01-01

419

An initial assessment of calcium and iron isotope systematics in forest ecosystems: clues to possible linkages?  

NASA Astrophysics Data System (ADS)

Calcium (Ca) and iron (Fe) are common major constituents of soils in watersheds and are essential nutrients for plants. Ca is potentially a limiting ecosystem nutrient due to its depletion from soil and biomass pools as a result of both anthropogenically-induced and natural leaching processes. In contrast, Fe is rarely limiting due to its typically greater abundance in soils as a result of the immobility of its oxidized weathering products. Although both Ca and Fe play critical roles in the biogeochemical dynamics of forest ecosystems, their differing chemical affinities provide little reason to expect similarities in biogeochemical behavior at the ecosystem level. However, initial assessments of the isotopic systematics of Ca at a watershed developed on granitoid glacial till in New Hampshire (USA) and of Fe at a watershed developed on marine sediments in northern California (USA) have revealed similar patterns of isotopic distribution and thus a potential linkage between their respective biogeochemical cycles. In each case, easily extractable Ca or Fe in the forest floor is isotopically heavier than residual Ca or Fe; in contrast, easily-extractable Ca or Fe in the deepest mineral soils is isotopically lighter than residual Ca or Fe. The development of these depth distributions of isotopic composition is consistent with either transport of relatively light, easily extractable Ca and Fe from deep mineral soils to shallow soils via plant root networks and/or soil water migration, or retention of relatively light Ca and Fe internally by plants with subsequent redistribution to and concentration in the shallow soils. An important role for the latter process is suggested at the New Hampshire site, where detailed analysis of red spruce tissues reveals that relatively light Ca is retained by foliage and bark, probably as a result of Ca-oxalate formation, and subsequently concentrated in the forest floor through litter deposition. We are currently determining the Fe isotope distribution in the soils at the New Hampshire site, the Ca isotope distribution in the soils and plants at the California site, and the Fe isotope distribution in the plants at both sites in order to understand potential linkages between the Ca and Fe biogeochemical cycles at these watersheds.

Bullen, T.; Fantle, M.; Aggarwal, J.; Bailey, S.

2004-05-01

420

California Waterfowl Association, Lyann Comrack,  

E-print Network

PRBO Conservation Science (PRBO) is dedicated to conserving birds, other wildlife, and ecosystems through innovative scientific research and effective outreach. California Partners In Flight (CalPIF) is a voluntary coalition of state and federal agencies and private conservation organizations dedicated to conserving bird populations and their habitats. Together, PRBO and CalPIF ensure that sound science is helping to guide conservation efforts and habitat management. For more information on PRBO, visit wwww.prbo.org. For more information on CalPIF, visit www.prbo.org/calpif. Contact Us Help support PRBOs mission to conserve birds and their ecosystems through research and outreach. You can join or make a donation online at www.prbo.org. To receive additional copies of this guide, please call PRBO Conservation Science at (707) 781-2555 x 307. For more information about PRBOs projects throughout the West, visit www.prbo.org. Give us your feedback at www.prbo.org/feedback. Copyright 2008 by

Nevada Foothills; Rene Cormier; Ryan Burnett; Melissa Pitkin; Rich Stallcup Provided; James R. Gallagher Sea; Sage Audubon; Martin Meyers; Eric Preston

421

Resilience, Integrity and Ecosystem Dynamics: Bridging Ecosystem Theory and Management  

NASA Astrophysics Data System (ADS)

In this paper different approaches to elucidate ecosystem dynamics are described, illustrated and interrelated. Ecosystem development is distinguished into two separate sequences, a complexifying phase which is characterized by orientor optimization and a destruction based phase which follows disturbances. The two developmental pathways are integrated in a modified illustration of the "adaptive cycle". Based on these fundamentals, the recent definitions of resilience, adaptability and vulnerability are discussed and a modified comprehension is proposed. Thereafter, two case studies about wetland dynamics are presented to demonstrate both, the consequences of disturbance and the potential of ecosystem recovery. In both examples ecosystem integrity is used as a key indicator variable. Based on the presented results the relativity and the normative loading of resilience quantification is worked out. The paper ends with the suggestion that the features of adaptability could be used as an integrative guideline for the analysis of ecosystem dynamics and as a well-suited concept for ecosystem management.

Mller, Felix; Burkhard, Benjamin; Kroll, Franziska

422

Resilience, Integrity and Ecosystem Dynamics: Bridging Ecosystem Theory and Management  

NASA Astrophysics Data System (ADS)

In this paper different approaches to elucidate ecosystem dynamics are described, illustrated and interrelated. Ecosystem development is distinguished into two separate sequences, a complexifying phase which is characterized by orientor optimization and a destruction based phase which follows disturbances. The two developmental pathways are integrated in a modified illustration of the adaptive cycle. Based on these fundamentals, the recent definitions of resilience, adaptability and vulnerability are discussed and a modified comprehension is proposed. Thereafter, two case studies about wetland dynamics are presented to demonstrate both, the consequences of disturbance and the potential of ecosystem recovery. In both examples ecosystem integrity is used as a key indicator variable. Based on the presented results the relativity and the normative loading of resilience quantification is worked out. The paper ends with the suggestion that the features of adaptability could be used as an integrative guideline for the analysis of ecosystem dynamics and as a well-suited concept for ecosystem management.

Mller, Felix; Burkhard, Benjamin; Kroll, Franziska

423

Seven: Southern California Survey  

E-print Network

Report. Southern California Earthquake Data Center.the Southern California region has about 10,000 earthquakes,Southern California residents have confidence in their local governments ability to respond quickly and effectively in the aftermath of a major earthquake.

Haselhoff, Kim; Ong, Paul

2006-01-01

424

From genes to ecosystems: a genetic basis to ecosystem services  

Microsoft Academic Search

Ecosystems provide services, many of which are regulated through species interactions. Emerging research in the fields of\\u000a community and ecosystem genetics indicate that genetic variation in one species can influence species interactions and affect\\u000a subsequent patterns of energy flow and nutrient cycles. Because there can be a genetic basis to community- and ecosystem-level\\u000a processes, evolutionary processes that alter standing genetic

Joseph K. Bailey

2011-01-01

425

The use of stable isotopes to study ecosystem gas exchange  

Microsoft Academic Search

Stable isotopes are a powerful research tool in environmental sciences and their use in ecosystem research is increasing.\\u000a In this review we introduce and discuss the relevant details underlying the use of carbon and oxygen isotopic compositions\\u000a in ecosystem gas exchange research. The current use and potential developments of stable isotope measurements together with\\u000a concentration and flux measurements of CO2

D. Yakir; L. da S. L. Sternberg

2000-01-01

426

Jampots: a Mashup System towards an E-Learning Ecosystem Bo Dong1, 2  

E-print Network

Jampots: a Mashup System towards an E-Learning Ecosystem Bo Dong1, 2 , Qinghua Zheng1, 2 , Lingzhi@gmail.com Abstract--Although E-Learning has grown into a revolutionary way of learning and is currently widely believed that an E-Learning ecosystem is the next generation E-Learning. Nowadays, the current trend of Web

Li, Haifei

427

California rides the tiger  

SciTech Connect

Revolutions rarely succeed without a struggle. At the California Public Utilities Commission (CPUC), the move to restructure the state`s electric utility industry is no exception. The stakes are enormous. For starters, annual revenues at the state`s investor-owned electric utilities (IOUs) exceed $18 billion, making up 2 percent of California`s gross state product. Competitively priced electricity is vital to California`s $800-billion-a-year economy, one would think. And with its sweeping restructing plan, the CPUC has found itself riding a tiger, hoping it won`t get swallowed whole in the process.

Garner, W.L.

1995-01-01

428

Using Fire Return Interval Departure (FRID) Analysis to Map Spatial and Temporal Changes in Fire Frequency on National Forest Lands in California.  

National Technical Information Service (NTIS)

In California, fire regimes and related ecosystem processes have been altered by land use practices associated with Euro-American settlement, and climate warming is exacerbating the magnitude and effects of these changes. Because of changing environmental...

H. D. Safford, K. M. Van de Water

2014-01-01

429

Tropical Ecosystem and Soil Development  

E-print Network

nutrient content and ecosystem development #12;How is soil generated from rocks? Weathering #12;SoilTropical Ecosystem and Soil Development Joost van Haren Ecology 596L 09/03/10 #12;Ecosystem biomass strongly dependent on soil Manaus, BDFF plots #12;0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 O ld oxisols

Saleska, Scott

430

Assessing risks to ecosystem quality  

SciTech Connect

Ecosystems are not organisms. Because ecosystems do not reproduce, grow old or sick, and die, the term ecosystem health is somewhat misleading and perhaps should not be used. A more useful concept is ``ecosystem quality,`` which denotes a set of desirable ecosystem characteristics defined in terms of species composition, productivity, size/condition of specific populations, or other measurable properties. The desired quality of an ecosystem may be pristine, as in a nature preserve, or highly altered by man, as in a managed forest or navigational waterway. ``Sustainable development`` implies that human activities that influence ecosystem quality should be managed so that high-quality ecosystems are maintained for future generations. In sustainability-based environmental management, the focus is on maintaining or improving ecosystem quality, not on restricting discharges or requiring particular waste treatment technologies. This approach requires management of chemical impacts to be integrated with management of other sources of stress such as erosion, eutrophication, and direct human exploitation. Environmental scientists must (1) work with decision makers and the public to define ecosystem quality goals, (2) develop corresponding measures of ecosystem quality, (3) diagnose causes for departures from desired states, and (4) recommend appropriate restoration actions, if necessary. Environmental toxicology and chemical risk assessment are necessary for implementing the above framework, but they are clearly not sufficient. This paper reviews the state-of-the science relevant to sustaining the quality of aquatic ecosystems. Using the specific example of a reservoir in eastern Tennessee, the paper attempts to define roles for ecotoxicology and risk assessment in each step of the management process.

Barnthouse, L.W. [Oak Ridge National Lab., TN (United States)

1995-12-31

431

Declining Birds in Grassland Ecosystems  

NSDL National Science Digital Library

This United States Geological Survey (USGS) publication discusses the grassland ecosystem with respect to declining bird species. This report is the effort of a number of agencies to develop a strategy for addressing grassland bird information needs. Grasslands are the most imperiled ecosystem worldwide, and birds associated with this ecosystem are on a decline. This report addresses monitoring issues, species in concern, and the effects of habitat and landscape on grassland birds.

432

Marine protected area networks in california, USA.  

PubMed

California responded to concerns about overfishing in the 1990s by implementing a network of marine protected areas (MPAs) through two science-based decision-making processes. The first process focused on the Channel Islands, and the second addressed California's entire coastline, pursuant to the state's Marine Life Protection Act (MLPA). We review the interaction between science and policy in both processes, and lessons learned. For the Channel Islands, scientists controversially recommended setting aside 30-50% of coastline to protect marine ecosystems. For the MLPA, MPAs were intended to be ecologically connected in a network, so design guidelines included minimum size and maximum spacing of MPAs (based roughly on fish movement rates), an approach that also implicitly specified a minimum fraction of the coastline to be protected. As MPA science developed during the California processes, spatial population models were constructed to quantify how MPAs were affected by adult fish movement and larval dispersal, i.e., how population persistence within MPA networks depended on fishing outside the MPAs, and how fishery yields could either increase or decrease with MPA implementation, depending on fishery management. These newer quantitative methods added to, but did not supplant, the initial rule-of-thumb guidelines. In the future, similar spatial population models will allow more comprehensive evaluation of the integrated effects of MPAs and conventional fisheries management. By 2011, California had implemented 132 MPAs covering more than 15% of its coastline, and now stands on the threshold of the most challenging step in this effort: monitoring and adaptive management to ensure ecosystem sustainability. PMID:25358301

Botsford, Louis W; White, J Wilson; Carr, Mark H; Caselle, Jennifer E

2014-01-01

433

Animal Ecosystem Engineers in Streams  

NSDL National Science Digital Library

This peer reviewed article from BioScience is about animal ecosystem engineers in streams. An impressive array of animals function as ecosystem engineers in streams through a variety of activities, ranging from nest digging by anadromous salmon to benthic foraging by South American fishes, from the burrowing of aquatic insects to the trampling of hippos. These ecosystem engineers have local impacts on benthic habitat and also strongly affect downstream fluxes of nutrients and other resources. The impacts of ecosystem engineers are most likely som