Sample records for california current ecosystem

  1. Mesopelagic fish biomass in the southern California current ecosystem

    NASA Astrophysics Data System (ADS)

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

    2015-02-01

    Mesopelagic fishes are the most common vertebrates on Earth, forming an important link between lower trophic levels and higher predators, and also between surface production and the deep sea. The biomass of these fishes is a key parameter for ecological modeling of oceanic ecosystems, but it is poorly known. The two most common methods to estimate the biomass of these fishes, acoustic and trawl surveys, are both sensitive to the ability of fishes to avoid nets. We show that size-dependent changes in trawl capture efficiency can affect acoustic estimates of biomass estimates 5-fold. We used both acoustic and trawl-based methods (informed by morphological data and acoustic modeling of individual backscattering) to estimate the biomass of mesopelagic fishes of southern California to be 25-37 g m-2 of ocean surface, a comparable density to that of inshore epipelagic zooplanktivorous fishes. Our results indicate that mesopelagic fishes are likely to play a major role in regional food webs.

  2. Atmospheric Wind Relaxations and the Oceanic Response in the California Current Large Marine Ecosystem

    Microsoft Academic Search

    M. R. Fewings; C. E. Dorman; L. Washburn; W. Liu

    2010-01-01

    On the West Coast of North America in summer, episodic relaxation of the upwelling-favorable winds causes warm water to propagate northward from southern to central California, against the prevailing currents [Harms and Winant 1998, Winant et al. 2003, Melton et al. 2009]. Similar wind relaxations are an important characteristic of coastal upwelling ecosystems worldwide. Although these wind relaxations have an

  3. Introduction to CCE-LTER: Responses of the California Current Ecosystem to climate forcing

    NASA Astrophysics Data System (ADS)

    Goericke, R.; Ohman, M. D.

    2015-02-01

    The California Current Ecosystem Long Term Ecological Research (CCE-LTER) site has been in existence since 2004. One of its primary objectives is to understand the response of the southern California Current ecosystem to climate forcing. The CCE-LTER site cooperates with the California Cooperative Oceanic Fisheries Investigations (CalCOFI) program and complements CalCOFI's work through more extensive observations, process studies, and a modeling program. This special issue is focused on the long-term observations made by the CCE-LTER and CalCOFI programs, describing and understanding long-term changes in the physical, chemical, and biotic environment in the region. The papers in this issue highlight the climatological conditions during recent years and employ modeling to diagnose the principal forcing of meridional currents and eddy transport, both of which affect biotic responses. Changes in source waters in the region, and altered flushing of the Santa Barbara Basin, are considered. Temporal variations in inherent optical properties and in higher trophic levels, including seabirds and marine mammals, are presented. Key methodological developments presented include the incorporation of subsurface phytoplankton and light distributions in order to improve remotely sensed measures of primary production, and the validation of multi-frequency acoustic estimates of mesopelagic fish biomass. Results also highlight significant spatial differences across the CCE-LTER region, including cross-shore trends in microbial assemblages, and glider-resolved frontal features and zones of mixing associated with abrupt topography. Alterations to the spatial structure of the pelagic ecosystem must also be considered when evaluating future climate-related changes.

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

    Microsoft Academic Search

    Ryan R. Rykaczewski; John P. Dunne

    2010-01-01

    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.

  5. Shearwaters as ecosystem indicators: Towards fishery-independent metrics of fish abundance in the California Current

    NASA Astrophysics Data System (ADS)

    Lyday, Shannon E.; Ballance, Lisa T.; Field, David B.; David Hyrenbach, K.

    2015-06-01

    Shearwaters are ideal for monitoring ocean conditions in the California Current because these predators are abundant, conspicuous, and responsive to oceanographic variability. Herein we evaluated black-vented (Puffinus opisthomelas), Buller's (P. bulleri), flesh-footed (P. carneipes), pink-footed (P. creatopus), short-tailed (P. tenuirostris), and sooty (P. griseus) shearwaters as fishery-independent indicators of predatory or prey fish availability. We analyzed four years (1996, 2001, 2005, 2008) of monthly (August-November) National Oceanic and Atmospheric Administration seabird surveys, and United States Geological Survey Pacific Coast Fisheries Database catch, from the California coast to 200 nm offshore. An ordination of shearwater abundance and fish catch revealed that the shearwaters and 11 fish/squid species were significantly correlated with one or more of three principal components, which explained 86% of the variation and revealed distinct species assemblages. We evaluated multiple linear regression models for 19 fisheries using five shearwater metrics: density, aggregation, and behavior (traveling, stationary, feeding), three oceanographic indices, and latitude. Eight of these models had a shearwater metric as the primary predictor. In particular, feeding black-vented shearwater abundance explained 75% of dolphinfish (Coryphaena hippurus) longline catch. This research illustrates the utility of shearwaters as ecosystem indicators, with direct application for predicting fishery catch of commercial importance.

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

    PubMed Central

    Moore, Jeffrey E.; Barlow, Jay P.

    2013-01-01

    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 1991–2008 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

  7. Declining abundance of beaked whales (family Ziphiidae) in the California Current large marine ecosystem.

    PubMed

    Moore, Jeffrey E; Barlow, Jay P

    2013-01-01

    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 1991-2008 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

  8. Species associations and redundancy in relation to biological hotspots within the northern California Current ecosystem

    NASA Astrophysics Data System (ADS)

    Reese, Douglas C.; Brodeur, Richard D.

    2015-06-01

    The dynamic nature of biological hotspots, while well recognized, is not well understood. We hypothesize that the persistence of hotspots in the northern California Current System (CCS), despite seasonal and annual changes in the nekton community species composition, is related to associations among species and their functional redundancy. To address this hypothesis, sampling was conducted during June and August of 2000 and 2002 within two hotspots occurring between Newport, Oregon and Crescent City, California in the coastal CCS. Associations were examined to identify potentially complementary and redundant species. The strongest negative associations were between jellyfish and fish species, with strong positive associations evident among several fish species. Dominant species varied seasonally and annually, although evidence indicated replacement of dominant species by other similar species with respect to functional group and preferred habitat. This finding suggests that the persistence of these biological hotspots is related to species redundancy and is an important attribute contributing to stability within this highly variable system.

  9. El Niño and similar perturbation effects on the benthos of the Humboldt, California, and Benguela Current upwelling ecosystems

    NASA Astrophysics Data System (ADS)

    Arntz, W. E.; Gallardo, V. A.; Gutiérrez, D.; Isla, E.; Levin, L. A.; Mendo, J.; Neira, C.; Rowe, G. T.; Tarazona, J.; Wolff, M.

    2006-03-01

    To a certain degree, Eastern Boundary Current (EBC) ecosystems are similar: Cold bottom water from moderate depths, rich in nutrients, is transported to the euphotic zone by a combination of trade winds, Coriolis force and Ekman transport. The resultant high primary production fuels a rich secondary production in the upper pelagic and nearshore zones, but where O2 exchange is restricted, it creates oxygen minimum zones (OMZs) at shelf and upper slope (Humboldt and Benguela Current) or slope depths (California Current). These hypoxic zones host a specifically adapted, small macro- and meiofauna together with giant sulphur bacteria that use nitrate to oxydise H2S. In all EBC, small polychaetes, large nematodes and other opportunistic benthic species have adapted to the hypoxic conditions and co-exist with sulphur bacteria, which seem to be particularly dominant off Peru and Chile. However, a massive reduction of macrobenthos occurs in the core of the OMZ. In the Humboldt Current area the OMZ ranges between <100 and about 600 m, with decreasing thickness in a poleward direction. The OMZ merges into better oxygenated zones towards the deep sea, where large cold-water mega- and macrofauna occupy a dominant role as in the nearshore strip. The Benguela Current OMZ has a similar upper limit but remains shallower. It also hosts giant sulphur bacteria but little is known about the benthic fauna. However, sulphur eruptions and intense hypoxia might preclude the coexistence of significant mega- und macrobenthos. Conversely, off North America the upper limit of the OMZ is considerably deeper (e.g., 500-600 m off California and Oregon), and the lower boundary may exceed 1000m. The properties described are valid for very cold and cold (La Niña and "normal") ENSO conditions with effective upwelling of nutrient-rich bottom water. During warm (El Niño) episodes, warm water masses of low oxygen concentration from oceanic and equatorial regions enter the upwelling zones, bringing a variety of (sub)tropical immigrants. The autochthonous benthic fauna emigrates to deeper water or poleward, or suffers mortality. However, some local macrofaunal species experience important population proliferations, presumably due to improved oxygenation (in the southern hemisphere), higher temperature tolerance, reduced competition or the capability to use different food. Both these negative and positive effects of El Niño influence local artisanal fisheries and the livelihood of coastal populations. In the Humboldt Current system the hypoxic seafloor at outer shelf depths receives important flushing from the equatorial zone, causing havoc on the sulphur bacteria mats and immediate recolonisation of the sediments by mega- and macrofauna. Conversely, off California, the intruding equatorial water masses appear to have lower oxygen than ambient waters, and may cause oxygen deficiency at upper slope depths. Effects of this change have not been studied in detail, although shrimp and other taxa appear to alter their distribution on the continental margin. Other properties and reactions of the two Pacific EBC benthic ecosystems to El Niño seem to differ, too, as does the overall impact of major episodes (e.g., 1982/1983(1984) vs. 1997/1998). The relation of the "Benguela Niño" to ENSO seems unclear although many Pacific-Atlantic ocean and atmosphere teleconnections have been described. Warm, low-oxygen equatorial water seems to be transported into the upwelling area by similar mechanisms as in the Pacific, but most major impacts on the eukaryotic biota obviously come from other, independent perturbations such as an extreme eutrophication of the sediments ensuing in sulphidic eruptions and toxic algal blooms. Similarities and differences of the Humboldt and California Current benthic ecosystems are discussed with particular reference to ENSO impacts since 1972/73. Where there are data available, the authors include the Benguela Current ecosystem as another important, non-Pacific EBC, which also suffers from the effects of hypoxia.

  10. Limacina helicina shell dissolution as an indicator of declining habitat suitability owing to ocean acidification in the California Current Ecosystem.

    PubMed

    Bednaršek, N; Feely, R A; Reum, J C P; Peterson, B; Menkel, J; Alin, S R; Hales, B

    2014-06-22

    Few studies to date have demonstrated widespread biological impacts of ocean acidification (OA) under conditions currently found in the natural environment. From a combined survey of physical and chemical water properties and biological sampling along the Washington-Oregon-California coast in August 2011, we show that large portions of the shelf waters are corrosive to pteropods in the natural environment. We show a strong positive correlation between the proportion of pteropod individuals with severe shell dissolution damage and the percentage of undersaturated water in the top 100 m with respect to aragonite. We found 53% of onshore individuals and 24% of offshore individuals on average to have severe dissolution damage. Relative to pre-industrial CO2 concentrations, the extent of undersaturated waters in the top 100 m of the water column has increased over sixfold along the California Current Ecosystem (CCE). We estimate that the incidence of severe pteropod shell dissolution owing to anthropogenic OA has doubled in near shore habitats since pre-industrial conditions across this region and is on track to triple by 2050. These results demonstrate that habitat suitability for pteropods in the coastal CCE is declining. The observed impacts represent a baseline for future observations towards understanding broader scale OA effects. PMID:24789895

  11. Delta Revival: Restoring a California Ecosystem

    USGS Publications Warehouse

    U.S. Geological Survey; California Bay Delta Authority

    2003-01-01

    'Delta Revival: Restoring a California Ecosystem' shows scientists from many disciplines working together to guide the unprecendented restoration of the Sacramento- San Joaquin Delta east of San Francisco Bay.

  12. Mapping Groundwater Dependent Ecosystems in California

    PubMed Central

    Howard, Jeanette; Merrifield, Matt

    2010-01-01

    Background Most groundwater conservation and management efforts focus on protecting groundwater for drinking water and for other human uses with little understanding or focus on the ecosystems that depend on groundwater. However, groundwater plays an integral role in sustaining certain types of aquatic, terrestrial and coastal ecosystems, and their associated landscapes. Our aim was to illuminate the connection between groundwater and surface ecosystems by identifying and mapping the distribution of groundwater dependent ecosystems (GDEs) in California. Methodology/Principal Findings To locate where groundwater flow sustains ecosystems we identified and mapped groundwater dependent ecosystems using a GIS. We developed an index of groundwater dependency by analyzing geospatial data for three ecosystem types that depend on groundwater: (1) springs and seeps; (2) wetlands and associated vegetation alliances; and (3) stream discharge from groundwater sources (baseflow index). Each variable was summarized at the scale of a small watershed (Hydrologic Unit Code-12; mean size?=?9,570 ha; n?=?4,621), and then stratified and summarized to 10 regions of relative homogeneity in terms of hydrologic, ecologic and climatic conditions. We found that groundwater dependent ecosystems are widely, although unevenly, distributed across California. Although different types of GDEs are clustered more densely in certain areas of the state, watersheds with multiple types of GDEs are found in both humid (e.g. coastal) and more arid regions. Springs are most densely concentrated in the North Coast and North Lahontan, whereas groundwater dependent wetlands and associated vegetation alliances are concentrated in the North and South Lahontan and Sacramento River hydrologic regions. The percentage of land area where stream discharge is most dependent on groundwater is found in the North Coast, Sacramento River and Tulare Lake regions. GDE clusters are located at the highest percentage in the North Coast (an area of the highest annual rainfall totals), North Lahontan (an arid, high desert climate with low annual rainfall), and Sacramento River hydrologic regions. That GDEs occur in such distinct climatic and hydrologic settings reveals the widespread distribution of these ecosystems. Conclusions/Significance Protection and management of groundwater-dependent ecosystems are hindered by lack of information on their diversity, abundance and location. By developing a methodology that uses existing datasets to locate GDEs, this assessment addresses that knowledge gap. We report here on the application of this method across California, but believe the method can be expanded to regions where spatial data exist. PMID:20585640

  13. California Coastal Upwelling Ecosystems and Ocean Observing Systems

    E-print Network

    Schladow, S. Geoffrey

    health and impacts of climate change. Measurements used for a wide range of scientific studies. RealCalifornia Coastal Upwelling Ecosystems and Ocean Observing Systems · California coastal upwelling) important? Provide information on the health of ecosystems. Generate future models predicting ecosystem

  14. 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)

    Yack, Tina M.

    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.)

  15. California current system - Predators and the preyscape

    NASA Astrophysics Data System (ADS)

    Ainley, David G.; Adams, Peter B.; Jahncke, Jaime

    2015-06-01

    The preyscape of the California Current System (CCS), one of the most productive marine areas on Earth (Glantz and Thompson, 1981), is highly variable, as evidenced by the papers in this issue, and as such presents a challenge to Ecosystem-based fishery management (EBFM), which attempts to integrate ecosystem considerations as part of fishery management and conservation decisions. Approaches to EBFM for the waters off Washington, Oregon, and California, the CCS, have been initiated (PFMC, 2007, 2013), and are continually being developed. To inform this process, a workshop was held in September 2013 to: i) gather together the existing information on forage fish and predator dynamics in the CCS; ii) consider temporal (seasonal, annual, decadal) and spatial availability of prey complexes and why these patterns of availability occur and change; iii) summarize and present that information for discussion to a large range of experts in oceanography, fish and fisheries management, seabirds, marine mammals, and ecosystem management; and, iv) synthesize this information to be useable by fishery agencies. The papers in this special Journal of Marine Systems issue address these four points. While the full results and recommendations can be found here - http://www.pointblue.org/uploads/assets/calcurrent/REPORT_Forage_Fish_Workshop_FINAL.pdf

  16. Through the stomach of a predator: Regional patterns of forage in the diet of albacore tuna in the California Current System and metrics needed for ecosystem-based management

    NASA Astrophysics Data System (ADS)

    Glaser, Sarah M.; Waechter, Katrina E.; Bransome, Nicole C.

    2015-06-01

    Foraging habits of predators can reveal patterns in prey ecology and guide ecosystem-based management by informing species interactions. This study describes the diet habits of albacore tuna in three regions (north, central, south) of the California Current System (CCS) and estimates the total predation mortality imposed on twenty prey taxa. The northern CCS was defined by predation on decapods, euphausiids, anchovy and hake. The central CCS was defined by predation on squid, hake and Pacific saury. The southern CCS was defined by predation on anchovy. We estimate North Pacific albacore consumed each year, on average, 54,000 mt of decapods and euphausiids, 43,000 mt of cephalopods, 84,000 mt of juvenile hake, 1600 mt of myctophids, 21,000 mt of juvenile sardine, 10,000 mt of juvenile rockfishes, almost 43,000 mt of Pacific saury, and over 107,000 mt of juvenile anchovy. While variability in predation certainly exists, this and prior studies show that diet habits of albacore are fairly stable through time. The northern CCS appears to be a more significant source of energy for albacore. When designing ecosystem-based approaches to the management of CCS-based fisheries, we recommend that the forage contribution of saury, hake and anchovy to the albacore population be considered.

  17. Predictability of the California Current System

    NASA Technical Reports Server (NTRS)

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

    2001-01-01

    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.

  18. Avian Conservation Practices Strengthen Ecosystem Services in California Vineyards

    Microsoft Academic Search

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

    2011-01-01

    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

  19. Ecosystem restoration on the California Channel Islands

    USGS Publications Warehouse

    Halvorson, W.L.

    2004-01-01

    Restoration of natural habitat has become increasingly important over the last three decades in the United States, first as mitigation for development (especially in wetlands), and more recently in natural areas. This latter restoration has come about as land managing agencies have seen the need to reverse the impact of past land uses and agencies like the National Park Service have taken on the responsibility for less-than-pristine lands. Restorations have typically been carried out with little prior study and with no follow-up monitoring. On the Channel Islands, the need for restoration is great, but the desire is to base this restoration on sound ecological understanding. By conducting surveys, implementing long-term research and monitoring, and by conducting population and community dynamics research, the necessary data is obtained to arrive at such an understanding. Once management actions have been taken to effect restoration, monitoring is used to determine the success of those actions. The intention is to gain enough of an understanding of the islands' ecosystems that we can manage to restore, not just populations of native plants and animals, but also the processes of a naturally functioning ecosystem. ?? International Scientific Publications, New Delhi.

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

    PubMed

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

    2014-01-01

    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

  1. Avian conservation practices strengthen ecosystem services in California vineyards.

    PubMed

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

    2011-01-01

    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

  2. Avian Conservation Practices Strengthen Ecosystem Services in California Vineyards

    PubMed Central

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

    2011-01-01

    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

  3. Characterizing conditions of California sage scrub communities in Mediterranean-type ecosystems using remote sensing

    Microsoft Academic Search

    Yuki Hamada

    2010-01-01

    Biodiversity loss is an urgent global issue. For California's Mediterranean-type ecosystems, protecting biologically diverse vegetation communities such as the California sage scrub (CSS) community type is vital to conserving rare, threatened, or endangered species, as well as overall species richness of the southern and Baja California region. While existing monitoring methods such as field surveys and vegetation type mapping provide

  4. Research of current situation and countermeasures of campus network ecosystem

    Microsoft Academic Search

    Xianghui Zhu; Fengqi Xie

    2012-01-01

    In order to look into the current situation of campus network ecosystem and establish a sound system, we carry out a survey about Wuhan Institute of Technology and find that there are some problems in university management and students themselves. This paper aims to put forward some suggestions for optimizing campus network ecosystem from the view of ecology. They are

  5. 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

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

    E-print Network

    levelslevels -- return rates can vary >10x with similarreturn rates can vary >10x with similar freshwater two weeks, since 1996 · Have historical data on hydrography and zooplankton from 1970s and 1983

  7. Satellite streamfunction analysis for the California current 

    E-print Network

    Arango, Hernan Guillermo

    1987-01-01

    Page ABSTRACT ACKNOWLEDGMENTS TABLE OF CONTENTS LIST OF FIGURES nl via I. INTRODUCTION A. California Current B. Satellite Instruments C. Satellite Mesoscale Studies D. Objective 1 2 3 7 II. THEORY A. Streamfunction Representation B... in Figure 4-7. Satellite-derived advective surface flow vectors (cm s t) plotted in the Cartesian domain. Satellite-derived sdvective surface flow vectors (cms ) plotted in the rotated Cartesian domain. Transform-generated coastline and seaward boundary...

  8. Ecosystem Change in California Grasslands: Impacts of Species Invasion

    NASA Astrophysics Data System (ADS)

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

    2009-12-01

    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 California’s 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.

  9. Assessment of potential aquatic herbicide impacts to California aquatic ecosystems.

    PubMed

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

    2008-10-01

    A series of legal decisions culminated in 2002 with the California State Water Resources Control Board funding the San Francisco Estuary Institute to develop and implement a 3-year monitoring program to determine the potential environmental impacts of aquatic herbicide applications. The monitoring program was intended to investigate the behavior of all aquatic pesticides in use in California, to determine potential impacts in a wide range of water-body types receiving applications, and to help regulators determine where to direct future resources. A tiered monitoring approach was developed to achieve a balance between program goals and what was practically achievable within the project time and budget constraints. Water, sediment, and biota were collected under "worst-case" scenarios in close association with herbicide applications. Applications of acrolein, copper sulfate, chelated copper, diquat dibromide, glyphosate, fluridone, triclopyr, and 2,4-D were monitored. A range of chemical analyses, toxicity tests, and bioassessments were conducted. At each site, risk quotients were calculated to determine potential impacts. For sediment-partitioning herbicides, sediment quality triad analysis was performed. Worst-case scenario monitoring and special studies showed limited short-term and no long-term toxicity directly attributable to aquatic herbicide applications. Risk quotient calculations called for additional risk characterizations; these included limited assessments for glyphosate and fluridone and more extensive risk assessments for diquat dibromide, chelated copper products, and copper sulfate. Use of surfactants in conjunction with aquatic herbicides was positively associated with greater ecosystem impacts. Results therefore warrant full risk characterization for all adjuvant compounds. PMID:18293029

  10. Modeling Studies of Climate Impacts and Extreme Events in California Mountain Ecosystems

    Microsoft Academic Search

    J. Shupe; C. Potter; M. Kramer; V. Genovese; P. Gross

    2005-01-01

    This study describes research using the CASA (Carnegie-Ames-Stanford) ecosystem model with HYDRA surface hydrologic model for the state of California to understand the effects of potential land cover and climate events on mountain ecosystems and regional water resources. The models are run at 1-km resolution to capture localized topographic effects at the regional scale. To assess HYDRA's ability to estimate

  11. Persistence of chlorinated hydrocarbon contamination in a California marine ecosystem

    SciTech Connect

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

    1989-01-01

    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.

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

    SciTech Connect

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

    1994-06-01

    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.

  13. The Economic Value of Coastal Ecosystems in California

    EPA Science Inventory

    The status of marine ecosystems affects the well being of human societies. These ecosystems include but are not limited to estuaries, lagoons, reefs, and systems further offshore such as deep ocean vents. The coastal regions that connect terrestrial and marine ecosystems are of p...

  14. Predator-Driven Nutrient Recycling in California Stream Ecosystems

    PubMed Central

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

    2013-01-01

    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

  15. Flows of biomass and structure in an exploited benthic ecosystem in the gulf of California, Mexico

    Microsoft Academic Search

    Francisco Arregu??n-Sánchez; Enrique Arcos; Ernesto A. Chávez

    2002-01-01

    We constructed a mass-balanced model of a benthic ecosystem exploited by shrimp trawlers in the Gulf of California, Mexico. The model is based on the software ecopath with ecosim Version 4a, which takes into account the contribution of functional groups to bycatch. The model represents the state of the ecosystem in 1978–79, and reflects the exploitation rate of shrimp at

  16. Salinity Variability in the California Current System

    NASA Astrophysics Data System (ADS)

    Kilpatrick, T.; Schneider, N.; di Lorenzo, E.

    2008-12-01

    A regional model is used to study the interannual to decadal salinity variability in the California Current (CC) system, using multiple simulations of 1950-2005. The model reproduces the mean structure, red variance spectrum, and the spiciness in the CalCoFI observations. However, the model standard deviation is too high by roughly 40%, and has too high positive skewness. The model also fails to reproduce the phase of the salinity time evolution; however the salinity shows variability between different realizations of the model, suggesting intrinsic variability as a contributing cause. To study the generation mechanism for low-frequency anomalies, we first try to remove the effect of isopycnal heave (associated with eddies) by using a density surface. Anomalies on the 1025.6 density surface at 36N have a decorrelation time scale of 23 months. Their generation is consistent with anomalous advection upstream in the CC, such that anomalously salty water in the CC is associated with a southward displacement of the North Pacific Current and weakened inflow from the north. Strong lateral gradients characterize the one-month averages of CC salinity, temperature and density. In the region southwest of the mean CC path, the salinity gradients are compensated and thus lack a strong dynamical signature. We propose that these dynamically passive salinity gradients are displaced by eddies and lead to the intrinsic variability observed there. At the region closer to Cape Mendocino, salinity gradients are associated with a density front and may be an active player in the dynamics.

  17. Sea Surface Temperature Influence on Terrestrial Gross Primary Production along the Southern California Current.

    PubMed

    Reimer, Janet J; Vargas, Rodrigo; Rivas, David; Gaxiola-Castro, Gilberto; Hernandez-Ayon, J Martin; Lara-Lara, Ruben

    2015-01-01

    Some land and ocean processes are related through connections (and synoptic-scale teleconnections) to the atmosphere. Synoptic-scale atmospheric (El Niño/Southern Oscillation [ENSO], Pacific Decadal Oscillation [PDO], and North Atlantic Oscillation [NAO]) decadal cycles are known to influence the global terrestrial carbon cycle. Potentially, smaller scale land-ocean connections influenced by coastal upwelling (changes in sea surface temperature) may be important for local-to-regional water-limited ecosystems where plants may benefit from air moisture transported from the ocean to terrestrial ecosystems. Here we use satellite-derived observations to test potential connections between changes in sea surface temperature (SST) in regions with strong coastal upwelling and terrestrial gross primary production (GPP) across the Baja California Peninsula. This region is characterized by an arid/semiarid climate along the southern California Current. We found that SST was correlated with the fraction of photosynthetic active radiation (fPAR; as a proxy for GPP) with lags ranging from 0 to 5 months. In contrast ENSO was not as strongly related with fPAR as SST in these coastal ecosystems. Our results show the importance of local-scale changes in SST during upwelling events, to explain the variability in GPP in coastal, water-limited ecosystems. The response of GPP to SST was spatially-dependent: colder SST in the northern areas increased GPP (likely by influencing fog formation), while warmer SST at the southern areas was associated to higher GPP (as SST is in phase with precipitation patterns). Interannual trends in fPAR are also spatially variable along the Baja California Peninsula with increasing secular trends in subtropical regions, decreasing trends in the most arid region, and no trend in the semi-arid regions. These findings suggest that studies and ecosystem process based models should consider the lateral influence of local-scale ocean processes that could influence coastal ecosystem productivity. PMID:25923109

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

    Microsoft Academic Search

    Brian B. Boroski; Richard T. Golightly

    2002-01-01

    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

  19. Collapse of the California Current During Glacial Maxima

    E-print Network

    Kurapov, Alexander

    abundances in the pollen of redwood, the distinctive component of the temperate rainforest of the north- west coast of California. In the region now dominated by the California Current, SSTs warmed 10,000 to 15 equatorward from the Oregon coast to just south of the U.S.-Mexico border, driven by prevailing winds (Fig. 1

  20. In the Schools: California Treat: Three Days in Five Ecosystems.

    ERIC Educational Resources Information Center

    Rigby, Jennifer A.

    1986-01-01

    Describes a 3-day program sponsored by the Orange County Marine Institute that provides biological, cultural, and historical learning experiences. Discusses the setting and activities of the five ecosystems explored by the students. The Chaparral to Ocean Science Camp includes chaparral, riparian, woodland, intertidal, and pelagic environments.…

  1. 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 ...

  2. 2013. Wetlands. In: Mooney, H. and Zavaleta, E., editors. Ecosystems of California: A Source Book. Berkeley, CA: University of California Press, p.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This publication is an introduction to wetland ecosystems in California, their geographic distribution, and historical ecology. Hydroclimatology and hydrology are explained as key drivers and patterns of variability in wetland habitats and biological communities. Primary wetland types are describe...

  3. The California current of the last glacial maximum: reconstruction at 42°N based on multiple proxies

    USGS Publications Warehouse

    Ortiz, Joseph D.; Mix, Alan C.; Hostetler, Steven W.; Kashgarian, Michaele

    1997-01-01

    Multiple paleoceanographic proxies in a zonal transect across the California Current near 42°N record modern and last glacial maximum (LGM) thermal and nutrient gradients. The offshore thermal gradient, derived from foraminiferal species assemblages and oxygen isotope data, was similar at the LGM to that at present (warmer offshore), but average temperatures were 3.3° ±1.5°C colder. Observed gradients require that the sites remained under the southward flow of the California Current, and thus that the polar front remained north of 42°N during the LGM. Carbon isotopic and foraminiferal flux data suggests enhanced nutrients and productivity of foraminfera in the northern California Current up to 650 km offshore. In contrast, marine organic carbon and coastal diatom burial rates decreased during the LGM. These seemingly contradictory results are reconciled by model simulations of the LGM wind- field, which suggest that wind stress curl at 42°N (and thus open-ocean upwelling) increased, while offshore Ekman transport (and thus coastal upwelling) decreased during the last ice age. The ecosystem of the northern California Current during the LGM approximated that of the modern Gulf of Alaska. Cooling and production in this region was thus driven by stronger open-ocean upwelling and/or southward flow of high-latitude water masses, rather than by coastal upwelling.

  4. Land use change and effects on water quality and ecosystem health in the Lake Tahoe basin, Nevada and California

    USGS Publications Warehouse

    Forney, William; Richards, Lora; Adams, Kenneth D.; Minor, Timothy B.; Rowe, Timothy G.; Smith, J. LaRue; Raumann, Christian G.

    2001-01-01

    Human activity in the Lake Tahoe Basin has increased substantially in the past four decades, causing significant impacts on the quality and clarity of the lake's famous deep, clear water. Protection of Lake Tahoe and the surrounding environment has become an important activity in recent years. A variety of agencies, including the Tahoe Regional Planning Agency, Tahoe Research Group of the University of California at Davis, Desert Research Institute of the University and Community College System of Nevada, U.S. Geological Survey (USGS), and a host of State (both Nevada and California) and local agencies have been monitoring and conducting research in the Basin in order to understand how the lake functions and to what extent humans have affected its landscape and ecosystem processes. In spite of all of these activities, there remains a lack of comprehensive land use change data and analysis for the Basin. A project is underway that unites the land cover mapping expertise of the USGS National Mapping Discipline with the hydrologic expertise of the Water Resources Discipline to assess the impacts of urban growth and land use change in the Lake Tahoe Basin. Three activities are planned over the next 3 years: (1) mapping the current and historic state of the land surface, (2) conducting analysis to document patterns, rates, and trends in urbanization, land use change, and ecosystem health, and (3) assessing the causes and consequences of land use change with regard to water quality and ecosystem health. We hypothesize that changes in the extent of urban growth and the corresponding increases in impervious surfaces and decreases in natural vegetation have resulted in severe impacts on ecosystem health and integrity, riparian zones and water quality over time. We are acting on multiple fronts to test this hypothesis through the quantification of landscape disturbances and impacts.

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

    E-print Network

    Pettijohn, Burkely Ashton

    2014-02-10

    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...

  6. Environmental conditions impacting juvenile Chinook salmon growth off central California: An ecosystem model analysis

    NASA Astrophysics Data System (ADS)

    Fiechter, J.; Huff, D. D.; Martin, B. T.; Jackson, D. W.; Edwards, C. A.; Rose, K. A.; Curchitser, E. N.; Hedstrom, K. S.; Lindley, S. T.; Wells, B. K.

    2015-04-01

    A fully coupled ecosystem model is used to identify the effects of environmental conditions and upwelling variability on growth of juvenile Chinook salmon in central California coastal waters. The ecosystem model framework consists of an ocean circulation submodel, a biogeochemical submodel, and an individual-based submodel for salmon. Simulation results indicate that years favorable for juvenile salmon growth off central California are characterized by particularly intense early season upwelling (i.e., March through May), leading to enhanced krill concentrations during summer near the location of ocean entry (i.e., Gulf of the Farallones). Seasonally averaged growth rates in the model are generally consistent with observed values and suggest that juvenile salmon emigrating later in the season (i.e., late May and June) achieve higher weight gains during their first 90 days of ocean residency.

  7. Sierra Nevada Ecosystem Project: Final report to Congress, Addendum. Davis: University of California, Centers for Water and Wildland Resources, 1996. MediatedSettlementAgreement

    E-print Network

    Stephens, Scott L.

    277 Sierra Nevada Ecosystem Project: Final report to Congress, Addendum. Davis: University of Wildlife, Fish and Conservation Biology University of California, Davis, CA SCOTT L. STEPHENS Department of California, Davis, CA DANA MURPHY Sierra Nevada Ecosystem Project Center University of California, Davis, CA

  8. Regime shifts in the Humboldt Current ecosystem [review article

    NASA Astrophysics Data System (ADS)

    Alheit, Jürgen; Niquen, Miguel

    2004-02-01

    Of the four major eastern boundary currents, the Humboldt Current (HC) stands out because it is extremely productive, dominated by anchovy dynamics and subject to frequent direct environmental perturbations of the El Niño Southern Oscillation (ENSO). The long-term dynamics of the HC ecosystem are controlled by shifts between alternating anchovy and sardine regimes that restructure the entire ecosystem from phytoplankton to the top predators. These regime shifts are caused by lasting periods of warm or cold temperature anomalies related to the approach or retreat of warm subtropical oceanic waters to the coast of Peru and Chile. Phases with mainly negative temperature anomalies parallel anchovy regimes (1950-1970; 1985 to the present) and the rather warm period from 1970 to 1985 was characterized by sardine dominance. The transition periods (turning points) from one regime to the other were 1968-1970 and 1984-1986. Like an El Nino, the warm periods drastically change trophic relationships in the entire HC ecosystem, exposing the Peruvian anchovy to a multitude of adverse conditions. Positive temperature anomalies off Peru drive the anchovy population close to the coast as the coastal upwelling cells usually offer the coolest environment, thereby substantially decreasing the extent of the areas of anchovy distribution and spawning. This enhances the effects of negative density-dependent processes such as egg and larval cannibalism and dramatically increases its catchability. Increased spatial overlap between anchovies and the warmer water preferring sardines intensifies anchovy egg mortality further as sardines feed heavily on anchovy eggs. Food sources for juvenile and adult anchovies which prey on a mixed diet of phyto- and zooplankton are drastically reduced because of decreased plankton production due to restricted upwelling in warm years, as demonstrated by lower zooplankton and phytoplankton volumes and the diminution of the fraction of large copepods, their main food source. Horse mackerel and mackerel, the main predators of anchovy, increase predation pressure on juvenile and adult anchovies due to extended invasion into the anchovy habitat in warmer years. In contrast to these periods of warm and cold temperature anomalies on the decadal scale, ENSO events do not play an important role for long-term anchovy dynamics, as the anchovy can recover even from strong ENSO events within 1-2 years. Consequently, the strong 1972-1973 ENSO event (in combination with overfishing) was not the cause of the famous crash of the Peruvian anchovy fishery in the 1970s.

  9. 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

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

    2010-01-01

    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

  10. Multi-decadal variations in calcareous holozooplankton in the California Current System: Thecosome pteropods, heteropods, and foraminifera

    NASA Astrophysics Data System (ADS)

    Ohman, Mark D.; Lavaniegos, Bertha E.; Townsend, Annie W.

    2009-09-01

    We examine long-term (1951-2008) variability of three major taxa of calcareous holozooplankton (aragonite-secreting thecosome pteropods and heteropods, and calcite-secreting large planktonic foraminifera) in light of recent interest in the impingement of waters undersaturated with respect to aragonite onto continental shelf depths in the California Current System. We assess interannual variability in springtime abundances of zooplankton sampled in the epipelagic layer, using CalCOFI (California Cooperative Oceanic Fisheries Investigations) zooplankton samples from two regions: Southern California (SC) and Central California (CC). Thecosome pteropods show no evidence of recent declines in abundance in SC or CC waters. In SC, sampling was sufficient to conclude that heteropods and large foraminifera also show no evidence of declines in abundance in recent years. These results do not preclude as-yet undetected changes in vertical distributions or shell morphology, and underscore the importance of sustained in situ measurement programs in order to detect and understand changes to pelagic ecosystems.

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

    PubMed Central

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

    2013-01-01

    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

  12. UNIVERSITY OF CALIFORNIA, Ion Flow Measurements and Plasma Current Analysis

    E-print Network

    Heidbrink, William W.

    UNIVERSITY OF CALIFORNIA, IRVINE Ion Flow Measurements and Plasma Current Analysis in the Irvine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 3.4 Data Acquisition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 3.5 Diagnostics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 4.4.1 Brushed vs. Brushless Motors . . . . . . . . . . . . . . . . . . 52 4.4.2 Motor Control

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

    SciTech Connect

    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

    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.

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

    NASA Astrophysics Data System (ADS)

    Brosnan, D. M.

    2013-12-01

    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.

  15. Equilibrium Structure and Dynamics of the California Current System

    Microsoft Academic Search

    Patrick Marchesiello; James C. McWilliams; Alexander Shchepetkin

    2003-01-01

    This paper addresses the structure and dynamical mechanisms of regional and mesoscale physical variability in the subtropical northeast Pacific Ocean using the Regional Oceanic Modeling System (ROMS). The model is configured with a U.S. West Coast domain that spans the California Current System (CCS) with a mesoscale horizontal resolution up to as fine as 3.5 km. Its mean-seasonal forcing is

  16. Biodiversity and Ecosystem Functioning: Current Knowledge and Future Challenges

    Microsoft Academic Search

    M. Loreau; S. Naeem; P. Inchausti; J. Bengtsson; J. P. Grime; A. Hector; D. U. Hooper; M. A. Huston; D. Raffaelli; B. Schmid; D. Tilman; D. A. Wardle

    2001-01-01

    The ecological consequences of biodiversity loss have aroused considerable interest and controversy during the past decade. Major advances have been made in describing the relationship between species diversity and ecosystem processes, in identifying functionally important species, and in revealing underlying mechanisms. There is, however, uncertainty as to how results obtained in recent experiments scale up to landscape and regional levels

  17. Biodiversity and Ecosystem Functioning: Current Knowledge and Future Challenges

    Microsoft Academic Search

    M. Loreau; S. Naeem; P. Inchausti; J. Bengtsson; J. P. Grime; A. Hector; D. U. Hooper; M. A. Huston; D. Raffaelli; B. Schmid; D. Tilman; D. A. Wardle

    1998-01-01

    The ecological consequences of biodiversity loss have aroused considerable interest and controversy during the past decade. Major advances have been made in describing the relationship between species diversity and ecosystem processes, in identifying functionally important species, and in revealing underlying mechanisms. There is, however, uncertainty as to how results obtained in recent experiments scale up to landscape and regional levels

  18. Estimating California ecosystem carbon change using process model and land cover disturbance data: 1951-2000

    USGS Publications Warehouse

    Liu, J.; Vogelmann, J.E.; Zhu, Z.; Key, C.H.; Sleeter, B.M.; Price, D.T.; Chen, J.M.; Cochrane, M.A.; Eidenshink, J.C.; Howard, S.M.; Bliss, N.B.; Jiang, H.

    2011-01-01

    Land use change, natural disturbance, and climate change directly alter ecosystem productivity and carbon stock level. The estimation of ecosystem carbon dynamics depends on the quality of land cover change data and the effectiveness of the ecosystem models that represent the vegetation growth processes and disturbance effects. We used the Integrated Biosphere Simulator (IBIS) and a set of 30- to 60-m resolution fire and land cover change data to examine the carbon changes of California's forests, shrublands, and grasslands. Simulation results indicate that during 1951-2000, the net primary productivity (NPP) increased by 7%, from 72.2 to 77.1TgCyr-1 (1 teragram=1012g), mainly due to CO2 fertilization, since the climate hardly changed during this period. Similarly, heterotrophic respiration increased by 5%, from 69.4 to 73.1TgCyr-1, mainly due to increased forest soil carbon and temperature. Net ecosystem production (NEP) was highly variable in the 50-year period but on average equalled 3.0TgCyr-1 (total of 149TgC). As with NEP, the net biome production (NBP) was also highly variable but averaged -0.55TgCyr-1 (total of -27.3TgC) because NBP in the 1980s was very low (-5.34TgCyr-1). During the study period, a total of 126Tg carbon were removed by logging and land use change, and 50Tg carbon were directly removed by wildland fires. For carbon pools, the estimated total living upper canopy (tree) biomass decreased from 928 to 834TgC, and the understory (including shrub and grass) biomass increased from 59 to 63TgC. Soil carbon and dead biomass carbon increased from 1136 to 1197TgC. Our analyses suggest that both natural and human processes have significant influence on the carbon change in California. During 1951-2000, climate interannual variability was the key driving force for the large interannual changes of ecosystem carbon source and sink at the state level, while logging and fire were the dominant driving forces for carbon balances in several specific ecoregions. From a long-term perspective, CO2 fertilization plays a key role in maintaining higher NPP. However, our study shows that the increase in C sequestration by CO2 fertilization is largely offset by logging/land use change and wildland fires. ?? 2011 Elsevier B.V.

  19. Multivariate ocean-climate indicators (MOCI) for the central California Current: Environmental change, 1990-2010

    NASA Astrophysics Data System (ADS)

    Sydeman, William J.; Thompson, Sarah Ann; García-Reyes, Marisol; Kahru, Mati; Peterson, William T.; Largier, John L.

    2014-01-01

    Temporal environmental variability may confound interpretations of management actions, such as reduced fisheries mortality when Marine Protected Areas are implemented. To aid in the evaluation of recent ecosystem protection decisions in central-northern California, we designed and implemented multivariate ocean-climate indicators (MOCI) of environmental variability. To assess the validity of the MOCI, we evaluated interannual and longer-term variability in relation to previously recognized environmental variability in the region, and correlated MOCI to a suite of biological indicators including proxies for lower- (phytoplankton, copepods, krill), and upper-level (seabirds) taxa. To develop the MOCI, we selected, compiled, and synthesized 14 well-known atmospheric and oceanographic indicators of large-scale and regional processes (transport and upwelling), as well as local atmospheric and oceanic response variables such as wind stress, sea surface temperature, and salinity. We derived seasonally-stratified MOCI using principal component analysis. Over the 21-year study period (1990-2010), the ENSO cycle weakened while extra-tropical influences increased with a strengthening of the North Pacific Gyre Oscillation (NPGO) and cooling of the Pacific Decadal Oscillation (PDO). Correspondingly, the Northern Oscillation Index (NOI) strengthened, leading to enhanced upwelling-favorable wind stress and cooling of air and ocean surface temperatures. The seasonal MOCI related well to subarctic copepod biomass and seabird productivity, but poorly to chlorophyll-a concentration and krill abundance. Our results support a hypothesis of enhanced sub-arctic influence (transport from the north) and upwelling intensification in north-central California over the past two decades. Such environmental conditions may favor population growth for species with sub-arctic zoogeographic affinities within the central-northern California Current coastal ecosystem.

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

    USGS Publications Warehouse

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

    2010-01-01

    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.

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

    E-print Network

    California at Santa Barbara, University of

    Depth-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 on high-elevation lakes, which are characterized by extreme oligotrophy and low inputs of organic matter

  2. Mesoscale structure and oceanographic determinants of krill hotspots in the California Current: Implications for trophic transfer and conservation

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

    Krill (crustaceans of the family Euphausiacea) comprise an important prey field for vast array of fish, birds, and marine mammals in the California Current and other large marine ecosystems globally. In this study, we test the hypothesis that mesoscale spatial organization of krill is related to oceanographic conditions associated with coastal upwelling. To test this, we compiled a climatology of krill distributions based on hydroacoustic surveys off California in May-June each year between 2000 and 2009 (missing 2007). Approximately 53,000 km of ocean habitat was sampled, resulting in a comprehensive geo-spatial data set from the Southern California Bight to Cape Mendocino. We determined the location and characteristics of eight definite and two probable krill “hotspots” of abundance. Directional-dependence analysis revealed that krill hotspots were oriented in a northwest-southeast (135°) direction, corresponding to the anisotropy of the 200-2000 m isobath. Krill hotspots were disassociated (inversely correlated) with three upwelling centers, Point Arena, Point Sur, and Point Conception, suggesting that krill may avoid locations of strong offshore transport or aggregate downstream from these locations. While current fisheries management considers the entire coast out to the 2000 m isobath critical habitat for krill in this ecosystem, we establish here smaller scale structuring of this critical mid-trophic level prey resource. Identifying mesoscale krill hotspots and their oceanographic determinants is significant as these smaller ecosystem divisions may warrant protection to ensure key ecosystem functions (i.e., trophic transfer) and resilience. Furthermore, delineating and quantifying krill hotspots may be important for conservation of krill-predators in this system.

  3. Topographic Controls on Southern California Ecosystem Function and Post-fire Recovery: a Satellite and Near-surface Remote Sensing Approach

    NASA Astrophysics Data System (ADS)

    Azzari, George

    Southern Californian wildfires can influence climate in a variety of ways, including changes in surface albedo, emission of greenhouse gases and aerosols, and the production of tropospheric ozone. Ecosystem post-fire recovery plays a key role in determining the strength, duration, and relative importance of these climate forcing agents. Southern California's ecosystems vary markedly with topography, creating sharp transitions with elevation, aspect, and slope. Little is known about the ways topography influences ecosystem properties and function, particularly in the context of post-fire recovery. We combined images from the USGS satellite Landsat 5 with flux tower measurements to analyze pre- and post-fire albedo and carbon exchanged by Southern California's ecosystems in the Santa Ana Mountains. We reduced the sources of external variability in Landsat images using several correction methods for topographic and bidirectional effects. We used time series of corrected images to infer the Net Ecosystem Exchange and surface albedo, and calculated the radiative forcing due to CO2 emissions and albedo changes. We analyzed the patterns of recovery and radiative forcing on north- and south-facing slopes, stratified by vegetation classes including grassland, coastal sage scrub, chaparral, and evergreen oak forest. We found that topography strongly influenced post-fire recovery and radiative forcing. Field observations are often limited by the difficulty of collecting ground validation data. Current instrumentation networks do not provide adequate spatial resolution for landscape-level analysis. The deployment of consumer-market technology could reduce the cost of near-surface measurements, allowing the installation of finer-scale instrument networks. We tested the performance of the Microsoft Kinect sensor for measuring vegetation structure. We used Kinect to acquire 3D vegetation point clouds in the field, and used these data to compute plant height, crown diameter, and volume. We found good agreement between Kinect-derived and manual measurements.

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

    NASA Astrophysics Data System (ADS)

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

    2012-11-01

    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.

  5. PROFESSIONAL INTERESTS Forest ecology, with an emphasis on productivity, biogeochemistry, and ecosystem dynamics. Current areas of research

    E-print Network

    Binkley, Dan

    Stewardship, Colorado State University; 1987present. Research and outreach on forest dynamics, includingApril 2012 PROFESSIONAL INTERESTS Forest ecology, with an emphasis on productivity, biogeochemistry, and ecosystem dynamics. Current areas of research focus on longterm changes in ecosystems

  6. Ecosystems

    NSDL National Science Digital Library

    Houghton Mifflin Science

    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.

  7. Current ecosystem processes in steppe near Lake Baikal

    NASA Astrophysics Data System (ADS)

    Vanteeva, Julia

    2015-04-01

    The steppes and forest steppes complexes of Priol'khonie at the Lake Baikal (southern Siberia, Russia) were studied in this research. Recreational activity has a significant impact on the Priol'khonie region. During soviet time this area was actively used for agriculture. Nowadays, this territory is the part of Pribaikalskyi National Park and special protection is needed. As the landscapes satisfy different human demands there are many land-management conflicts. The specific climate and soil conditions and human activity lead to erosion processes on study area. Sediment loads are transferred into the Lake Baikal and cause water pollution. Consequently, vegetation cover and phytomass play an important role for regulating hydrological processes in the ecosystems. The process of phytomass formation and its proactive role playing on sedimentation and mitigate silt detaching by rill and inter-rill erosion are considered in the research as important indicators of the ecosystem functions for steppe landscapes. These indicators were studied for the different land cover types identified on the area because the study area has a large variety of steppe and forest steppe complexes, differing in the form of relief, soil types, vegetation species composition and degree of land degradation. The fieldwork was conducted in the study area in the July and August of 2013. Thirty-two experimental sites (10 x 10 m) which characterized different types of ecosystem were established. The level of landscape degradation was estimated. The method of clipping was used for the valuation of above-ground herbaceous phytomass. The phytomass of tree stands was calculated using the volume-conversion rates for forest-steppe complexes. For the quantification of transferred silt by inter-rill erosion in different conditions (vegetation, slope, soil type, anthropogenic load) a portable rainfall simulator was created with taking into account the characteristics of the study area. The aboveground herbaceous phytomass of the steppe complexes varied from 0.4 to 2.64 t/ha. Apical stony and sloping grass-forb landscapes and areas of settlements and recreation facilities had the lowest values. Forest steppes were characterized by low crown density, non-large stand density, which was represented mainly by larch. Phytomass stock ranged from 30.78 to 282.24 t/ha. Maximum values corresponded to the forest steppe with larch on steep slopes. The maximum values of the silt matter transfer (up to 124 g /m2) corresponded to areas with a strong recreation pressure with the lower value of vegetation cover (from 0 to 45%) and aboveground herbaceous phytomass (0.4 - 0.6 t/ha). During experiment with using rainfall simulator defined different sensibility to soil erosion, for example, for Caragana steppe with sagebrush on the undisturbed area trapped silt is 12 g/m2 and for anthropogenic disturbed patch - 84 g/m2. For Sagebrush steppe trapped silt changed from 4 to 16 g/m2. The study shows strong landscapes transformation leading to loss of biodiversity, the reduction of phytomass production and water percolation.

  8. Measurement of Ecosystem Metabolism across Climatic and Vegetation Gradients in California

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

    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.

  9. Seasonal dynamics of physical and biological processes in the central California Current System: A modeling study

    NASA Astrophysics Data System (ADS)

    Guo, Lin; Chai, Fei; Xiu, Peng; Xue, Huijie; Rao, Shivanesh; Liu, Yuguang; Chavez, Francisco P.

    2014-08-01

    A 3-D physical and biological model is used to study the seasonal dynamics of physical and biological processes in the central California Current System. Comparisons of model results with remote sensing and in situ observations along CalCOFI Line 67 indicate our model can capture the spatial variations of key variables (temperature, nutrients, chlorophyll, and so on) on annual mean and seasonal cycle. In the coastal upwelling system, it is the alongshore wind stress that upwells high nutrients to surface from 60 m and stimulates enhanced plankton biomass and productivity in the upwelling season. As a result, coastal species peak in the late upwelling period (May-July), and oceanic species reach the annual maxima in the oceanic period (August-October). The annual maximum occurs in the late upwelling period for new production and in the oceanic period for regenerated production. From the late upwelling period to the oceanic period, stratification is intensified while coastal upwelling becomes weaker. Correspondingly, the coastal ecosystem retreats from ˜300 to ˜100 km offshore with significant decline in chlorophyll and primary production, and the oceanic ecosystem moves onshore. During this transition, the decline in phytoplankton biomass is due to the grazing pressure by mesozooplankton in the 0-150 km domain, but is regulated by low growth rates in the 150-500 km offshore domain. Meanwhile, the growth rates of phytoplankton increase in the coastal waters due to deeper light penetration, while the decrease in offshore growth rates is caused by lower nitrate concentrations.

  10. Diet variability of forage fishes in the Northern California Current System

    NASA Astrophysics Data System (ADS)

    Hill, Andrew D.; Daly, Elizabeth A.; Brodeur, Richard D.

    2015-06-01

    As fisheries management shifts to an ecosystem-based approach, understanding energy pathways and trophic relationships in the Northern California Current (NCC) will become increasingly important for predictive modeling and understanding ecosystem response to changing ocean conditions. In the NCC, pelagic forage fishes are a critical link between seasonal and interannual variation in primary production and upper trophic groups. We compared diets among dominant forage fish (sardines, anchovies, herring, and smelts) in the NCC collected in May and June of 2011 and June 2012, and found high diet variability between and within species on seasonal and annual time scales, and also on decadal scales when compared to results of past studies conducted in the early 2000s. Copepoda were a large proportion by weight of several forage fish diets in 2011 and 2012, which differed from a preponderance of Euphausiidae found in previous studies, even though all years exhibited cool ocean conditions. We also examined diet overlap among these species and with co-occurring subyearling Chinook salmon and found that surf smelt diets overlapped more with subyearling Chinook diets than any other forage fish. Herring and sardine diets overlapped the most with each other in our interdecadal comparisons and some prey items were common to all forage fish diets. Forage fish that show plasticity in diet may be more adapted to ocean conditions of low productivity or anomalous prey fields. These findings highlight the variable and not well-understood connections between ocean conditions and energy pathways within the NCC.

  11. Characterizing conditions of California sage scrub communities in Mediterranean-type ecosystems using remote sensing

    NASA Astrophysics Data System (ADS)

    Hamada, Yuki

    Biodiversity loss is an urgent global issue. For California's Mediterranean-type ecosystems, protecting biologically diverse vegetation communities such as the California sage scrub (CSS) community type is vital to conserving rare, threatened, or endangered species, as well as overall species richness of the southern and Baja California region. While existing monitoring methods such as field surveys and vegetation type mapping provide ecologically valuable information, they do not provide information about internal conditions of CSS communities. Fractional cover of plant life forms is frequently utilized to examine conditions of (semi-)arid vegetation communities. For the CSS community type, however, the utility of life-form fractional cover has not received adequate attention as an effective monitoring variable indicating ecological integrity; thus, no reliable, cost-effective methods have been developed. This dissertation investigates the effectiveness of fractional cover of true shrub, subshrub, herb, and bare ground for quantifying CSS community conditions, tests remote sensing approaches to obtain spatially comprehensive life-form cover fractions, and explores the utility of life-form fractional cover maps for sustainable, effective long-term monitoring of CSS communities of southern California. Past studies indicate that fractional cover of plant life forms is an effective measure for quantifying CSS community integrity, and remote sensing is the only means to estimate spatially exhaustive cover fractions cost-effectively over large extent. Among the remote sensing approaches tested, object-based image analysis using pansharpened QuickBird imagery shows the most promise for estimating life-form fractional cover within CSS communities because of its high accuracy (e.g., RMSE as low as 6.4%) and robustness in estimating cover fractions and ability of providing life-form-level landscape metrics. Multiple Endmember Spectral Mixture Analysis using SPOT imagery is capable of estimating cover fractions with comparable accuracy and is beneficial for retrospective analysis for life-form cover changes and cost-effective ecological monitoring. Using spatially exhaustive life-form cover fractions, maps indicating CSS community conditions and species' life-form cover preference were generated. Such maps can fill information gaps between field-based data and vegetation type maps and provide valuable information about habitat recovery, habitat suitability, and ecological integrity of CSS communities. By combining these methods, more effective CSS community monitoring can be achieved.

  12. Current developments in groundwater ecology--from biodiversity to ecosystem function and services.

    PubMed

    Griebler, Christian; Malard, Florian; Lefébure, Tristan

    2014-06-01

    Groundwater ecosystems constitute the largest terrestrial freshwater biome. They are dark, extremely low in energy and do not provide much space but they contain an unexpectedly high diversity of living forms showing characteristic adaptive features. The restricted accessibility along with the enormous 'invisible' heterogeneity challenged for a long time testing of scientific theories and unraveling of ecosystem functioning. Triggered by an improved interdisciplinarity, comprehensive sampling strategies and current developments in biotechnology and statistical analysis, groundwater ecology gains momentum entering a new era of research. We are only beginning to understand adaptive mechanisms, species distribution patterns and ecosystem functioning. Ninety-five percent of global liquid freshwater is stored in the terrestrial subsurface constituting a major source of water for drinking, irrigation and industrial purposes. There is an urgent need to integrate evolutionary and ecological research for developing a holistic perspective of the functional roles of biodiversity and ecosystem services and predicting global changes under alternative groundwater resource use scenarios. PMID:24590188

  13. Anthropogenic currents and shoreline water quality in Avalon Bay, California.

    PubMed

    Ho, Lin C; Litton, Rachel M; Grant, Stanley B

    2011-03-15

    Shoreline concentrations of fecal indicator bacteria (FIB) and fecal indicator viruses (FIV) in Avalon Bay (Catalina Island, California) display a marked diurnal pattern (higher at night and lower during the day) previously attributed to the tidal flux of sewage-contaminated groundwater and the tidal washing of contaminated sediments, coupled with light and dark die-off of FIB and FIV (Boehm, et al., Environ. Sci. Technol. 2009, 43, 8046-8052). In this paper we document the existence of strong (peak velocities between 20 to 40 cm/s) transient currents in the nearshore waters of Avalon Bay that occur between 07:00 and 20:00 each day. These currents, which have a significant onshore component, are generated by anthropogenic activities in the Bay, including prop wash from local boat traffic and the docking practices of large passenger ferries. A budget analysis carried out on simultaneous measurements of FIB at two cross-shore locations indicates that anthropogenic currents contribute to the diurnal cycling of FIB concentrations along the shoreline, by transporting relatively unpolluted water from offshore toward the beach. The data and analysis presented in this paper support the idea that anthropogenic currents represent a significant, and previously overlooked, source of variability in shoreline water quality. PMID:21329349

  14. Water Use in Los Angeles, California: Consumption Patterns, Ecosystem Response and Impact on Regional Water Budgets

    NASA Astrophysics Data System (ADS)

    Hogue, T. S.

    2014-12-01

    The City of Los Angeles relies heavily on external water sources, primarily the Eastern Sierra, Northern California and the Colorado River, and approximately 90% of the City's water supply is snowpack dependent. In recent years, water conservation measures have been implemented in response to regional drought, which include a tiered pricing structure and watering restrictions. As a result of implemented conservation policies, Los Angeles reported the lowest water consumption per capita per day in 2011 among cities over 1 million people in the U.S. This presentation will highlight our ongoing work to better understand the coupling between humans, ecosystems and water across the City of Los Angeles, especially during the recent drought period. Our work is unique in that we integrate social, ecological, and hydrologic data, including ten years of residential water consumption data for the entire city of Los Angeles, extensive groundwater well data, socio-economic information and remote sensing to evaluate relationships as well as spatial and temporal patterns. Developed statistical models demonstrated that Single-Family Residential (SFR) water use across the City is primarily driven by household income, landscape greenness, water rates and water volume allocation,, with higher consumption rates in the northern, warmer and more affluent parts, and lower consumption rates in the less affluent neighborhoods near Downtown. Landscape use also varies greatly across the city, averaging 50% of total SFR. Our evaluation of conservation efforts shows that the combination of mandatory watering restrictions and price increase led to a water reduction of 23%, while voluntary restrictions led to only a 6% reduction in water use. Relationships of water use to ecosystems (greenness) and groundwater variability were also evaluated and will be highlighted. Our ultimate goal is to improve predictions of human-water interactions in order to drive policy change and guide future demand strategies under uncertain climate variability and a growing urban population.

  15. Molecular hydrogen uptake by soils in forest, desert, and marsh ecosystems in California

    NASA Astrophysics Data System (ADS)

    Smith-Downey, Nicole V.; Randerson, James T.; Eiler, John M.

    2008-09-01

    The mechanism and environmental controls on soil hydrogen (H2) uptake are not well understood but are essential for understanding the atmospheric H2 budget. Field observations of soil H2 uptake are limited, and here we present the results from a series of measurements in forest, desert, and marsh ecosystems in southern California. We measured soil H2 fluxes using flux chambers from September 2004 to July 2005. Mean H2 flux rates and standard deviations were -7.9 + -4.2, -7.6 + -5.3 and -7.5 + -3.4 nmol m-2 s-1 for the forest, desert, and marsh, respectively (corresponding to deposition velocities of 0.063 + -0.029, 0.051 + -0.036, 0.035 + -0.013 cm s-1). Soil profile measurements showed that H2 mixing ratios were between 3% and 51% of atmospheric levels at 10 cm and that the penetration of H2 into deeper soil layers increased with soil drying. Soil removal experiments in the forest demonstrated that the litter layer did not actively consume H2, the removal of this layer increased uptake by deeper soil layers, and the exposure of subsurface soil layers to ambient atmospheric H2 levels substantially increased their rate of uptake. Similar soil removal experiments at the desert site showed that extremely dry surface soils did not consume H2 and that fluxes at the surface increased when these inactive layers were removed. We present a model of soil H2 fluxes and show that the diffusivity of soils, along with the vertical distribution of layers that actively consume H2 regulate surface fluxes. We found that soil organic matter, CO2 fluxes, and ecosystem type were not strong controllers of H2 uptake. Our experiments highlight H2 diffusion into soils as an important limit on fluxes and that minimum moisture level is needed to initiate microbial uptake.

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

    USGS Publications Warehouse

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

    2003-01-01

    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.

  17. Sierra Nevada Ecosystem Project: Final report to Congress, Addendum. Davis: University of California, Centers for Water and Wildland Resources, 1996. Lake Tahoe Case Study

    E-print Network

    Stephens, Scott L.

    217 Sierra Nevada Ecosystem Project: Final report to Congress, Addendum. Davis: University-FISK Department of Wildlife, Fish and Conservation Biology University of California, Davis, CA THOMAS C. CAHILL Air Quality Group, Crocker Nuclear Laboratory University of California, Davis, CA OWEN K. DAVIS

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

    PubMed Central

    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

    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

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

    PubMed

    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

    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

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

    PubMed

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

    2014-01-01

    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:24991934

  1. Fog and Rain Water Influences on Tree Physiology and Ecosystem Function in a California Redwood Forest

    NASA Astrophysics Data System (ADS)

    Ewing, H. A.; Weathers, K. C.; Dawson, T. E.; Templer, P. H.; Firestone, M. K.; Elliott, A. M.; Boukili, V. K.

    2008-12-01

    Fog is thought to influence ecological function in coastal forests worldwide, yet few data are available that illuminate the mechanisms underlying this influence. In a California redwood forest we measured water fluxes from horizontally moving fog and vertically delivered rain as well as redwood tree function. The spatial heterogeneity of water fluxes, water availability, tree water use, and water movement varied greatly across seasons. Across the forest as a whole, 98% of water flux to the soil occurred in the rain season and was relatively even across the whole forest. In contrast, below-canopy flux of fog water declined exponentially from the windward edge to the forest interior. Following large fog events, soil moisture was greater at the windward edge than anywhere else in the forest. Physiological activity in redwoods reflected these differences in inputs across seasons: tree physiological responses did not vary spatially in the rain season, but in the fog season, water use was greater, yet water stress was less, in trees at the windward edge of the forest versus the interior. In both seasons, vertical passage through the forest changed the amount of water, revealing the role of both the tree canopy and roots in processing atmospheric inputs. While total fog water inputs were comparatively small, they may have important ecosystem functions, including relief of canopy water stress and, where there is fog drip, functional coupling of above- and below-ground processes.

  2. The Benguela Current: An ecosystem of four components

    NASA Astrophysics Data System (ADS)

    Hutchings, L.; van der Lingen, C. D.; Shannon, L. J.; Crawford, R. J. M.; Verheye, H. M. S.; Bartholomae, C. H.; van der Plas, A. K.; Louw, D.; Kreiner, A.; Ostrowski, M.; Fidel, Q.; Barlow, R. G.; Lamont, T.; Coetzee, J.; Shillington, F.; Veitch, J.; Currie, J. C.; Monteiro, P. M. S.

    2009-12-01

    The Benguela system is one of the four major eastern boundary upwelling systems of the world. It is unusual as there are two stratified subtropical or warm temperate boundary regions, on either side of the major wind-driven upwelling region(19-34°S), which itself is subdivided at 26°S by the powerful Luderitz upwelling cell. Important biological components cross the boundary areas at different stages to complete the life-history cycle. While the “Bakun triad” of factors responsible for the development of large pelagic fish populations (enrichment, concentration and retention) provide an important unifying principle for understanding the compromise implicit in adaptation to upwelling systems, the role of predation has been neglected, as has the fish yield relative to photosynthesis. The role global climate change will have in the Benguela in terms of shifting boundaries or weakening or intensifying gradients is being explored. The interannual and decadal signals are so strong in the region that long term trends are difficult to distinguish. Intensive resource utilisation and the collapse of several fish stocks occurred in the Benguela region during the 1960s and 1970s, with different recovery trajectories in the north and the south. The Angolan subsystem can be described as a subtropical transition zone between the wind-driven upwelling system and the Equatorial Atlantic, with gentle upwelling-favourable winds, well-defined seasons, intermediate productivity and moderate, declining fisheries. It is separated from the Namibian subsystem by the Angola-Benguela front. The northern Benguela shelf is a typical coastal upwelling system with equatorward winds, cool water, high plankton biomass and moderate to high fish biomass, which is currently in a depleted state. A shift from sardines to horse mackerel occurred during the period 1970-1990, while hake have never fully recovered from intensive fishing pressure up to 1990. Widespread oxygen-depleted waters and sulphur eruptions result from local and remote forcing, restricting the habitat available for pelagic and demersal fish species. The Luderitz-Orange River Cone is an intensive perennial upwelling cell where strong winds, high turbulence and strong offshore transport constitute a partial barrier to epipelagic fish species. Upwelling source water alters in salinity and oxygen, across this boundary zone. A decline in upwelling-favourable winds occurred between 1990 and 2005. The southern Benguela region is characterised by a pulsed, seasonal, wind-driven upwelling at discrete centres and warm Agulhas water offshore. High primary productivity forms a belt of enrichment along the coast, constrained by a front. Low-oxygen water, which only occurs close inshore, may adversely affect some resources. The west coast is primarily a nursery ground for several fish species which spawn on the Agulhas Bank and are transported by alongshore jet currents to the west coast. The Agulhas Bank forms the southern boundary of the Benguela system and it displays characteristics of both an upwelling and a temperate shallow shelf system, with seasonal stratification and mixing, coastal, shelf-edge and dynamic upwelling, moderate productivity and a well oxygenated shelf. A large biomass of fish occupies the Bank during the summer season, with some evidence for tight coupling between trophic levels. A cool ridge of upwelled water, with links to coastal upwelling and to the Agulhas Current, appears to play an important but poorly understood role affecting the distribution and productivity of pelagic fish. A boom in sardine and anchovy populations was accompanied by an eastward shift, followed by 5 years of poor recruitment by sardine but successful recruitment of anchovy, indicating changes in the early life-history patterns of these two species.

  3. Biomasses of Euphausiids and Smaller Zooplankton in the California Current-Geographic and

    E-print Network

    Biomasses of Euphausiids and Smaller Zooplankton in the California Current. Conversi ABSTRACT: We examined data on size-fraction- ated zooplankton biomasses from the California Current in summer to 1) verify that euphausiid and smaller zooplankton biomasses varied in similar ways

  4. The California Current system: The seasonal variability of its physical characteristics

    Microsoft Academic Search

    Ronald J. Lynn; James J. Simpson

    1987-01-01

    The seasonal variation of the physical characteristics and of large-scale current patterns of the California Current system is examined using harmonic analysis applied to the 23 years of California cooperative Oceanic Fisheries Investigations data collected between 1950 and 1978. The amplitude and phasing of seasonal variation in dynamic height and the overall standard deviation of dynamic height define three domains:

  5. 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 are discussed in relation to mechanisms of land-sea DDT residue transfer. DDT residue concentrations

  6. Decadal changes in the Canary Current Upwelling Ecosystem

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

    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).

  7. Exploration of the California Current System with seismic oceanography

    NASA Astrophysics Data System (ADS)

    Biescas-Gorriz, B.; Mojica, J. F.; Bornstein, G.; Bartlett, A.; Nedimovic, M. R.; Sallares, V.; Ruddick, B. R.; Carbotte, S. M.; Canales, J.; Carton, H. D.

    2012-12-01

    Seismic oceanography is a discipline that studies physical properties of the oceanic water from multichannel seismic reflection data. Multichannel seismic reflection data image mesoscale structures in the ocean like fronts, eddies and currents with lateral resolution on the order of 10 m. These data reveal the lateral coherence of thermohaline oceanic structures as well as the interactions with the topography. This discipline uses the same instrumentation and software for data acquisition and processing that marine geophysics, but it uses the first 5-6 seconds of the seismic records, which travel through the water column. The "Juan de Fuca Ridge to Trench" survey was carried out in the Cascadia Basin during last June-July 2012. The water column above Cascadia Basin is affected by the California Current System. There were two research vessel involved in this geophysical survey: RV Marcus Langseth, which was in charged of the multichannel seismic reflection data acquisition and the RV Oceanus, which was in charged of the ocean bottom seismometers. We had the opportunity of acquiring XBTs and XSVs simultaneously to the seismic acquisition from the RV Marcus Langseth and the RV Oceanus offered to us the opportunity of doing CTD space-coincident casts of the seismic acquisition, in order to compare the seismic images with the temperature, salinity and sound velocity data. We present in this work the seismic images of two eddies that were recorded in the survey and their comparison with the physical properties of the ocean.

  8. Ecosystems

    NSDL National Science Digital Library

    R. Herzog

    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.

  9. Indirect effects of conservation policies on the coupled human-natural ecosystem of the upper Gulf of California.

    PubMed

    Morzaria-Luna, Hem Nalini; Ainsworth, Cameron H; Kaplan, Isaac C; Levin, Phillip S; Fulton, Elizabeth A

    2013-01-01

    High bycatch of non-target species and species of conservation concern often drives the implementation of fisheries policies. However, species- or fishery-specific policies may lead to indirect consequences, positive or negative, for other species or fisheries. We use an Atlantis ecosystem model of the Northern Gulf of California to evaluate the effects of fisheries policies directed at reducing bycatch of vaquita (Phocoena sinus) on other species of conservation concern, priority target species, and metrics of ecosystem function and structure. Vaquita, a Critically Endangered porpoise endemic to the Upper Gulf of California, are frequently entangled by finfish gillnets and shrimp driftnets. We tested five fishery management scenarios, projected over 30 years (2008 to 2038), directed at vaquita conservation. The scenarios consider progressively larger spatial restrictions for finfish gillnets and shrimp driftnets. The most restrictive scenario resulted in the highest biomass of species of conservation concern; the scenario without any conservation measures in place resulted in the lowest. Vaquita experienced the largest population increase of any functional group; their biomass increased 2.7 times relative to initial (2008) levels under the most restrictive spatial closure scenario. Bycatch of sea lions, sea turtles, and totoaba decreased > 80% in shrimp driftnets and at least 20% in finfish gillnet fleets under spatial management. We found indirect effects on species and ecosystem function and structure as a result of vaquita management actions. Biomass and catch of forage fish declined, which could affect lower-trophic level fisheries, while other species such as skates, rays, and sharks increased in both biomass and catch. When comparing across performance metrics, we found that scenarios that increased ecosystem function and structure resulted in lower economic performance indicators, underscoring the need for management actions that consider ecological and economic tradeoffs as part of the integrated management of the Upper Gulf of California. PMID:23691155

  10. Indirect Effects of Conservation Policies on the Coupled Human-Natural Ecosystem of the Upper Gulf of California

    PubMed Central

    Morzaria-Luna, Hem Nalini; Ainsworth, Cameron H.; Kaplan, Isaac C.; Levin, Phillip S.; Fulton, Elizabeth A.

    2013-01-01

    High bycatch of non-target species and species of conservation concern often drives the implementation of fisheries policies. However, species- or fishery-specific policies may lead to indirect consequences, positive or negative, for other species or fisheries. We use an Atlantis ecosystem model of the Northern Gulf of California to evaluate the effects of fisheries policies directed at reducing bycatch of vaquita (Phocoena sinus) on other species of conservation concern, priority target species, and metrics of ecosystem function and structure. Vaquita, a Critically Endangered porpoise endemic to the Upper Gulf of California, are frequently entangled by finfish gillnets and shrimp driftnets. We tested five fishery management scenarios, projected over 30 years (2008 to 2038), directed at vaquita conservation. The scenarios consider progressively larger spatial restrictions for finfish gillnets and shrimp driftnets. The most restrictive scenario resulted in the highest biomass of species of conservation concern; the scenario without any conservation measures in place resulted in the lowest. Vaquita experienced the largest population increase of any functional group; their biomass increased 2.7 times relative to initial (2008) levels under the most restrictive spatial closure scenario. Bycatch of sea lions, sea turtles, and totoaba decreased > 80% in shrimp driftnets and at least 20% in finfish gillnet fleets under spatial management. We found indirect effects on species and ecosystem function and structure as a result of vaquita management actions. Biomass and catch of forage fish declined, which could affect lower-trophic level fisheries, while other species such as skates, rays, and sharks increased in both biomass and catch. When comparing across performance metrics, we found that scenarios that increased ecosystem function and structure resulted in lower economic performance indicators, underscoring the need for management actions that consider ecological and economic tradeoffs as part of the integrated management of the Upper Gulf of California. PMID:23691155

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

    PubMed Central

    Micheli, Fiorenza; Halpern, Benjamin S.; Walbridge, Shaun; Ciriaco, Saul; Ferretti, Francesco; Fraschetti, Simonetta; Lewison, Rebecca; Nykjaer, Leo; Rosenberg, Andrew A.

    2013-01-01

    Management of marine ecosystems requires spatial information on current impacts. In several marine regions, including the Mediterranean and Black Sea, legal mandates and agreements to implement ecosystem-based management and spatial plans provide new opportunities to balance uses and protection of marine ecosystems. Analyses of the intensity and distribution of cumulative impacts of human activities directly connected to the ecological goals of these policy efforts are critically needed. Quantification and mapping of the cumulative impact of 22 drivers to 17 marine ecosystems reveals that 20% of the entire basin and 60–99% of the territorial waters of EU member states are heavily impacted, with high human impact occurring in all ecoregions and territorial waters. Less than 1% of these regions are relatively unaffected. This high impact results from multiple drivers, rather than one individual use or stressor, with climatic drivers (increasing temperature and UV, and acidification), demersal fishing, ship traffic, and, in coastal areas, pollution from land accounting for a majority of cumulative impacts. These results show that coordinated management of key areas and activities could significantly improve the condition of these marine ecosystems. PMID:24324585

  12. Microbial Enzymatic Response to Reduced Precipitation and Added Nitrogen in a Southern California Grassland Ecosystem

    NASA Astrophysics Data System (ADS)

    Alster, C. J.; German, D.; Allison, S. D.

    2011-12-01

    Microbial enzymes play a fundamental role in ecosystem processes and nutrient mineralization. Although there have been many studies concluding that global climate change affects plant communities, the effects on microbial communities in leaf litter have been much less studied. We measured extracellular enzyme activities in litter decomposing in plots with either reduced precipitation or increased nitrogen in a grassland ecosystem in Loma Ridge National Landmark in Southern California. We used a reciprocal transplant design to examine the effects of plot treatment, litter origin, and microbial community origin on litter decomposition and extracellular enzyme activity. Our hypothesis was that increased nitrogen would increase activity because nitrogen often limits microbial growth, while decreased precipitation would decrease activity due to lower litter moisture levels. Samples were collected in March 2011 and analyzed for the activities of cellobiohydrolase (CBH), ?-glucosidase (BG), ?-glucosidase (AG), N-acetyl-?-D-glucosaminidase (NAG), ?-xylosidase (BX), acid phosphatase (AP), and leucine aminopeptidase (LAP). None of the factors in the nitrogen manipulation had a significant effect on any of the enzymes, although BG, CBH, and NAG increased marginally significantly in plots with nitrogen addition (p = 0.103, p = 0.082, and p = 0.114, respectively). For the precipitation manipulation, AG, BG, BX, CBH, and NAG significantly increased in plots with reduced precipitation (p = 0.015, p <0.001, p<0.001, and p<0.001, respectively) while LAP significantly decreased (p = 0.002). LAP catalyzes the hydrolysis of polypeptides, so reduced LAP activity could result in lower rates of enzyme turnover in the reduced precipitation treatment. We also observed that AP significantly increased (p = 0.014) in litter originating from reduced precipitation plots, while AG, BX, and LAP significantly decreased (p = 0.011, p = 0.031, and 0.005, respectively). There were no significant correlations found between fungal or bacterial mass and enzymatic activity with either of the treatment types. Our results suggest that increased enzymatic activity due to drought could mitigate negative effects of moisture limitation on decomposition. However, this mitigating effect may be offset by declines in enzyme activity due to changes in plant community composition and associated litter chemistry in response to drought.

  13. 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)

    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

    To 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.

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

    NASA Astrophysics Data System (ADS)

    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

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2010-11-01

    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 California, identified by increased tree pollen relative to pollen from grasslands and scrublands, are found on every major deglaciation in the last 600 kyr. Sea surface temperature (SST) data were collected for the last two deglaciations. Wet periods are associated with a rapid rise in SST off central California. SST gradients along the California margin and changes in biogenic deposition show that wet periods in central California are associated with a weakening of the California Current and weakened coastal upwelling. High carbonate production suggests that there was significant curl-of-wind stress upwelling offshore. We propose that wet periods in central California are associated with a meteorological connection to the tropical Pacific and weakened southward flow in the California Current that shunted temperate Pacific water northward into the Alaska gyre. We do not observe evidence for a south-shifted westerly storm track at the last glacial maximum but find that wet periods are diachronous along the California margin. The wettest period around the Santa Barbara Basin peaked at 16 ka, preceding the wet peak in central and northern California by 4 kyr.

  16. Material properties of Pacific hake, Humboldt squid, and two species of myctophids in the California Current.

    PubMed

    Becker, Kaylyn N; Warren, Joseph D

    2015-05-01

    Material properties of the flesh from three fish species (Merluccius productus, Symbolophorus californiensis, and Diaphus theta), and several body parts of the Humboldt squid (Dosidicus gigas) collected from the California Current ecosystem were measured. The density contrast relative to seawater varied within and among taxa for fish flesh (0.9919-1.036), squid soft body parts (mantle, arms, tentacle, braincase, eyes; 1.009-1.057), and squid hard body parts (beak and pen; 1.085-1.459). Effects of animal length and environmental conditions on nekton density contrast were investigated. The sound speed contrast relative to seawater varied within and among taxa for fish flesh (0.986-1.027) and Humboldt squid mantle and braincase (0.937-1.028). Material properties in this study are similar to values from previous studies on species with similar life histories. In general, the sound speed and density of soft body parts of fish and squid were 1%-3% and 1%-6%, respectively, greater than the surrounding seawater. Hard parts of the squid were significantly more dense (6%-46%) than seawater. The material properties reported here can be used to improve target strength estimates from acoustic scattering models, which could increase the accuracy of biomass estimates from acoustic surveys for these nekton. PMID:25994685

  17. Current and Future Effects of Mexican Immigration in California. Executive Summary. R-3365/1-CR.

    ERIC Educational Resources Information Center

    McCarthy, Kevin F.; Valdez, R. Burciaga

    This study to assess the current situation of Mexican immigrants in California and project future possibilities constructs a demographic profile of the immigrants, examines their economic effects on the state, and describes their socioeconomic integration into California society. Models of immigration/integration processes are developed and used…

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

    NASA Astrophysics Data System (ADS)

    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

    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.

  19. Integrated biochemical, molecular genetic, and bioacoustical analysis of mesoscale variability of the euphausiid Nematoscelis difficilis in the California Current

    NASA Astrophysics Data System (ADS)

    Bucklin, Ann; Wiebe, Peter H.; Smolenack, Sara B.; Copley, Nancy J.; Clarke, M. Elizabeth

    2002-03-01

    Integrated assessment of the euphausiid Nematoscelis difficilis (Crustacea; Euphausiacea) and the zooplankton assemblage of the California Current was designed to investigate individual, population, and community responses to mesoscale variability in biological and physical characters of the ocean. Zooplankton samples and observational data were collected along a cross-shelf transect of the California Current in association with the California Cooperative Fisheries Investigations (CalCOFI) Survey during October 1996. The transect crossed three domains defined by temperature and salinity: nearshore, mid-Current, and offshore. Individual N. difficilis differed in physiological condition along the transect, with higher size-corrected concentrations of four central metabolic enzymes (citrate synthetase, hexokinase, lactate dehydrogenase (LDH), and phosphoglucose isomerase (PGI)) for euphausiids collected in nearshore waters than in mid-Current and offshore waters. There was little variation in the DNA sequences of the genes encoding PGI and LDH (all DNA changes were either silent or heterozygous base substitutions), suggesting that differences in enzyme concentration did not result from underlying molecular genetic variation. The population genetic makeup of N. difficilis varied from sample to sample based on haplotype frequencies of mitochondrial cytochrome oxidase I (mtCOI; P=0.029). There were significant differences between pooled nearshore and offshore samples, based on allele frequencies at two sites of common substitutions in the mtCOI sequence ( P=0.020 and 0.026). Silhouette and bioacoustical backscattering measurements of the zooplankton assemblage of the top 100 m showed marked diel vertical migration of the scattering layer, of which euphausiids were a small but significant fraction. The biochemical and molecular assays are used as indices of complex physiological (i.e., growth and condition) and genetic (i.e., mortality) processes; the bioacoustical observations provide insight into the ecosystem context for the single-species measurements. All data are intended for integration into predictive models of secondary production and biomass concentration in the ocean.

  20. DISTRIBUTION, SIZE, AND ABUNDANCE OF MICROCOPEPODS IN THE CALIFORNIA CURRENT SYSTEM AND THEIR POSSIBLE

    E-print Network

    AND THEIR POSSIBLE INFLUENCE ON SURVIVAL OF MARINE TELEOST LARVAEl DAVID K. ARTHUR" ABSTRACT The California Current stages ofsmall cope- pods. Yokota et al. (1961) found that food occur- ring in the feeding larvae of all

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

    NASA Astrophysics Data System (ADS)

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

    2006-12-01

    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.

  2. Rizzo, D. M. 2003. Sudden Oak Death: Host plants in forest ecosystems in California and Oregon. Sudden Oak Death Online Symposium. www.apsnet.org/online/SOD (website of The

    E-print Network

    Rizzo, D. M. 2003. Sudden Oak Death: Host plants in forest ecosystems in California and Oregon. Sudden Oak Death Online Symposium. www.apsnet.org/online/SOD (website of The American Phytopathological Society). doi:10.1094/SOD-2003-DR Sudden Oak Death: Host plants in forest ecosystems in California

  3. 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

    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

    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 (2000–2004), which included a severe drought in 2002 and a subsequent wildfire in

  4. Salinity Variations in the Southern California Current* NIKLAS SCHNEIDER

    E-print Network

    Wang, Yuqing

    Research Center, and Department of Oceanography, University of Hawaii at Manoa, Honolulu, Hawaii EMANUELE upwelling, sup- ports a highly productive and complex ecosystem. This system has sparked the interest. Schneider, IPRC, University of Hawaii at Manoa, 1680 East West Road, Honolulu, HI 96822. E-mail: nschneid@hawaii

  5. Two coastal upwelling domains in the northern California Current system

    E-print Network

    domain, to strong small-scale wind stress curl in the lee of Cape Blanco, and to the reduced influence and Patricia A. Wheeler1 ABSTRACT A pair of hydrographic sections, one north and one south of Cape Blanco at 42 off Crescent City, California, lies 300 km farther south and spans a narrower shelf. Summer winds

  6. CURRENT DISTRIBUTION OF THE FISHER, MARTES PENNANTI, IN CALIFORNIA

    Microsoft Academic Search

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

    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

  7. Current status of Citrus tristeza virus in Central California

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Lindcove Research and Extension Center (LREC), Exeter, CA has 51 ha of citrus and is the field site and screenhouses for the University of California Citrus Clonal Protection Program (CCPP). LREC maintains a zero tolerance of Citrus tristeza virus (CTV) infected trees to protect the CCPP and re...

  8. Dynamic connectivity in the Southern California Bight and Georges Bank: Identifying ecosystem interactions using chaotic time series analysis

    NASA Astrophysics Data System (ADS)

    Ye, H.; Deyle, E. R.; Hsieh, C.; Sugihara, G.

    2012-12-01

    We used convergent cross mapping (CCM), a method grounded in nonlinear dynamical systems theory to analyze long-term time series of fish species from the California Cooperative Oceanic Fisheries Investigations ichthyoplankton (isolated to the Southern California Bight [SCB]) and NOAA National Marine Fisheries Service Northeast Fisheries Science Center trawl survey (isolated to the Georges Bank [GB] region) data sets. CCM gives a nonparametric indicator of the realized dynamic influence that one species has on another (i.e. how much the abundance of X at a particular time is dependent on the historical abundance of Y). We found there are more interactions between species in SCB compared to GB. An analysis of the interaction matrix showed that there is also more structure in the connectivity network of SCB compared to GB. We attribute this difference in connectivity to historical overexploitation of fish stocks in the North Atlantic, and reproduce this effect in simple multi-species fishery models. We discuss the implications of these results for ecosystem-based management and for restoration efforts.; Connectivity Networks for Fishes in the Southern California Bight (SCB) and Georges Bank (GB) as determined using cross-mapping.

  9. Fine Root Production across a Primary Successional Ecosystem Chronosequence at Mt. Shasta, California

    Microsoft Academic Search

    Shauna M. Uselman; Robert G. Qualls; Juliane Lilienfein

    2007-01-01

    Estimating changes in belowground biomass and production is essential for understanding fundamental patterns and processes\\u000a during ecosystem development. We examined patterns of fine root production, aboveground litterfall, and forest floor accumulation\\u000a during forest primary succession at the Mt. Shasta Mudflows ecosystem chronosequence. Fine root production was measured using\\u000a the root ingrowth cores method over 1 year, and aboveground litterfall was collected

  10. Collapse of the California Current during glacial maxima linked to climate change on land.

    PubMed

    Herbert, T D; Schuffert, J D; Andreasen, D; Heusser, L; Lyle, M; Mix, A; Ravelo, A C; Stott, L D; Herguera, J C

    2001-07-01

    Time series of alkenone unsaturation indices gathered along the California margin reveal large (4 degrees to 8 degrees C) glacial-interglacial changes in sea surface temperature (SST) over the past 550,000 years. Interglacial times with SSTs equal to or exceeding that of the Holocene contain peak abundances in the pollen of redwood, the distinctive component of the temperate rainforest of the northwest coast of California. In the region now dominated by the California Current, SSTs warmed 10,000 to 15,000 years in advance of deglaciation at each of the past five glacial maxima. SSTs did not rise in advance of deglaciation south of the modern California Current front. Glacial warming along the California margin therefore is a regional signal of the weakening of the California Current during times when large ice sheets reorganized wind systems over the North Pacific. Both the timing and magnitude of the SST estimates suggest that the Devils Hole (Nevada) calcite record represents regional but not global paleotemperatures, and hence does not pose a fundamental challenge to the orbital ("Milankovitch") theory of the Ice Ages. PMID:11441174

  11. Collapse of the California Current During Glacial Maxima Linked to Climate Change on Land

    NASA Astrophysics Data System (ADS)

    Herbert, T. D.; Schuffert, J. D.; Andreasen, D.; Heusser, L.; Lyle, M.; Mix, A.; Ravelo, A. C.; Stott, L. D.; Herguera, J. C.

    2001-07-01

    Time series of alkenone unsaturation indices gathered along the California margin reveal large (4° to 8°C) glacial-interglacial changes in sea surface temperature (SST) over the past 550,000 years. Interglacial times with SSTs equal to or exceeding that of the Holocene contain peak abundances in the pollen of redwood, the distinctive component of the temperate rainforest of the northwest coast of California. In the region now dominated by the California Current, SSTs warmed 10,000 to 15,000 years in advance of deglaciation at each of the past five glacial maxima. SSTs did not rise in advance of deglaciation south of the modern California Current front. Glacial warming along the California margin therefore is a regional signal of the weakening of the California Current during times when large ice sheets reorganized wind systems over the North Pacific. Both the timing and magnitude of the SST estimates suggest that the Devils Hole (Nevada) calcite record represents regional but not global paleotemperatures, and hence does not pose a fundamental challenge to the orbital (``Milankovitch'') theory of the Ice Ages.

  12. Phytoplankton scales of variability in the California Current System: 1. Interannual and cross-shelf variability

    E-print Network

    Thomas, Andrew

    . Introduction [2] The California Current System (CCS) is an eastern boundary flow that originates southward flow produce meanders and eddies around the core of the coastal jet [e.g., Marchesiello et al., 1998; Soto-Mardones et al., 2004; Barth et al., 2005]. Moored current meters reveal the dominance

  13. Carbon Sequestration and Nitrous Oxide Emissions from Urban Turfgrass Ecosystems in Southern California

    Microsoft Academic Search

    M. D. Ampleman; C. I. Czimczik; A. Townsend-Small; S. E. Trumbore

    2008-01-01

    Irrigated turfgrass ecosystems sequester carbon in soil organic matter, but they may also release nitrous oxide, due to fertilization associated with intensive management practices. Nitrous oxide is an important green house gas with a global warming potential (GWP) of 300 times that of carbon dioxide on a 100 yr time horizon. Although regular irrigation and fertilization of turfgrass create favorable

  14. Climate Effects on Soil Carbon Sequestration in a Grass, Oak and Conifer Ecosystem of California

    Microsoft Academic Search

    S. L. Pittiglio; R. Zasoski

    2007-01-01

    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. Previous studies have shown that the main process controlling DOM mobility in soils is sorption in the mineral horizons that adds to stabilized organic matter pools. The

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

    PubMed Central

    Pec, Gregory J.; Carlton, Gary C.

    2014-01-01

    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

  16. Last Century Patterns of Surface Ocean and Diatom Variability in the Southern California Current

    NASA Astrophysics Data System (ADS)

    Esparza, M.; Herguera, J.; Lange, C. B.

    2006-12-01

    A time series reconstruction for the last 100 years of the variability of diatoms from laminated sediments off the southern Baja California margin shows the sensitivity of this phytoplankton group to oceanographic variability in the California Current on different timescales. Here we show that cool (warm) years are associated with higher (lower) diatom accumulation values, a proxy for their export production from the water column to the seafloor. There is a clear direction in the changes of the opaline flora community structure throughout the past century that parallels the observed trend towards higher SSTs in the southern part of the California Current. The diatom succession is reflected in three types of assemblages that show a clear progression from cool spring to early summer bloom species in the earlier part of the century towards alternating cool California Current and warm subtropical waters during the mid-century, to subtropical and tropical assemblages reflecting more stratified oligotrophic conditions during the latter part of the last century. This association between opaline floral succession and the SST anomaly trend implies a long term change that cannot be explained by the same mechanisms that are commonly associated with the typical interannual or interdecadal oceanographic variability. A small group of diatom species appears to follow the periodic swings of the large scale Pacific Decadal Oscilation index. The Coscinodiscus argus/radiatus and Coscinodiscus decrescens/marginatus complexes, commonly found in the California Current waters, closely follow the inter- decadal variability patterns over the Pacific, although with a decreasing amplitude after the mid 1970s shift. We will further discuss the implications of both observations on the direction of the observed changes and the cyclicity in the opaline floral record in terms of the oceanographic variability in the southern boundary of the California Current.

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

    USGS Publications Warehouse

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

    1997-01-01

    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.

  18. Zooplankton community pattern associated with a California Current cold filament

    NASA Astrophysics Data System (ADS)

    Mackas, David L.; Washburn, Libe; Smith, Sharon L.

    1991-08-01

    In July 1988 we sampled upper layer zooplankton distributions in and around a major cold filament located off Point Arena, California. Average zooplankton biomass levels declined inshore to offshore, but relatively high levels extended seaward along the cool side of the filament jet. A series of transverse station lines shows strong shifts in community composition across the axis of the filament. The cross-filament compositional sequence was recognizably similar along each line, giving an impression (supported by cluster analysis and along-flow versus cross-flow spatial autocorrelation) of banding parallel to the filament axis. The "standard" sequence was characterized by local maxima of Dolioletta gegenbauri in nonfilament waters to the south and east, Euphausia pacifica along the southeast margin of the filament, Eucalanus californicus and euphausiid larvae within the cool core of the filament and extending partway across the strong seaward jet on the north and west margin of the filament, and heteropod larvae, chaetognaths, Dolioletta, and a mixture of small copepods (including several with southern and offshore faunal affinities) along the warm side of the jet and extending into nonfilament waters to the north and west. A "core" group of samples characterized by high abundance of Eucalanus matched the trajectories of drifters released at the upstream end of the filament. Both crossed geopotential anomaly contours (to larger ?) as they moved out the filament, suggesting a cross-jet component of motion.

  19. Zooplankton Distribution and Transport in the California Current off Oregon4 , Zhou M.1*

    E-print Network

    Pierce, Stephen

    1 1 2 3 Zooplankton Distribution and Transport in the California Current off Oregon4 5 6 Wu D.1;2 ABSTRACT: The transport and retention of zooplankton biomass in the shelf and25 slope regions off Oregon resolution28 measurements of temperature, salinity, depth, fluorescence and zooplankton29 abundance

  20. ANNUAL FLUCTUATIONS IN BIOMASS OF TAXONOMIC GROUPS OF ZOOPLANKTON IN THE CALIFORNIA CURRENT, 1955-59

    E-print Network

    ANNUAL FLUCTUATIONS IN BIOMASS OF TAXONOMIC GROUPS OF ZOOPLANKTON IN THE CALIFORNIA CURRENT, 1955-59 J. M. COLEBROOK' ABSTRACT Year-to-year fluctuations in the abundance of the zooplankton of zooplankton as well as an index of "trophodynamic complexity." The categories were chosen to represent

  1. Transport and coastal zooplankton communities in the northern California Current system

    E-print Network

    Kurapov, Alexander

    Transport and coastal zooplankton communities in the northern California Current system Hongsheng) was estimated from a 15 year time series of zooplankton samples (1996­2010) collected biweekly at a coastal dynamics. Citation: Bi, H., W. T. Peterson, and P. T. Strub (2011), Transport and coastal zooplankton

  2. 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 CURRENT MARSH J. YOUNGBLUTH1 ABSTRAcr The density, vertical range, and diel movement of total zooplankton biomass as well as a smaller number and higher density of several species. Diel vertical movement among

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

    Microsoft Academic Search

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

    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,

  4. Carbon Sequestration and Nitrous Oxide Emissions from Urban Turfgrass Ecosystems in Southern California

    NASA Astrophysics Data System (ADS)

    Ampleman, M. D.; Czimczik, C. I.; Townsend-Small, A.; Trumbore, S. E.

    2008-12-01

    Irrigated turfgrass ecosystems sequester carbon in soil organic matter, but they may also release nitrous oxide, due to fertilization associated with intensive management practices. Nitrous oxide is an important green house gas with a global warming potential (GWP) of 300 times that of carbon dioxide on a 100 yr time horizon. Although regular irrigation and fertilization of turfgrass create favorable conditions for both C storage and N2O release via nitrification and denitrification by soil microbes, emissions from these highly managed ecosystems are poorly constrained. We quantified N2O emissions and C storage rates for turf grass in four urban parks in the city of Irvine, CA. The turf grass systems we studied were managed by the City of Irvine. Parks were established between 1975 and 2006 on former range land with the same initial parent material; are exposed to the same climate; and form a time series (chronosequence) for investigating rates of C accumulation. We also investigated the effects of management (e.g. grass species, fertilization rate), soil moisture and temperature, and park age on N2O emission from these parks. We quantified N2O emissions using static soil chamber with four 7 min. sampling intervals, and analyzed the samples using an electron capture gas chromatograph. Soil carbon accumulation rates were determined from the slope of the organic C inventory (from 0-20 cm depth) plotted against park age. C storage rates for soils in "leisure" areas were close to 2 Mg C ha-1 yr-1, similar to rates associated with forest regrowth in northeastern US forests. However, as park age and C storage increased, N2O emissions increased as well, such that emissions from the older parks (~20 ngN m-2 s-1) were comparable to published temperate agricultural fluxes. Initial estimates suggest that the GWP associated with N2O emissions approximately offsets the effect of C storage in these ecosystems.

  5. Land Use Compounds Habitat Losses under Projected Climate Change in a Threatened California Ecosystem

    PubMed Central

    Riordan, Erin Coulter; Rundel, Philip W.

    2014-01-01

    Given the rapidly growing human population in mediterranean-climate systems, land use may pose a more immediate threat to biodiversity than climate change this century, yet few studies address the relative future impacts of both drivers. We assess spatial and temporal patterns of projected 21st century land use and climate change on California sage scrub (CSS), a plant association of considerable diversity and threatened status in the mediterranean-climate California Floristic Province. Using a species distribution modeling approach combined with spatially-explicit land use projections, we model habitat loss for 20 dominant shrub species under unlimited and no dispersal scenarios at two time intervals (early and late century) in two ecoregions in California (Central Coast and South Coast). Overall, projected climate change impacts were highly variable across CSS species and heavily dependent on dispersal assumptions. Projected anthropogenic land use drove greater relative habitat losses compared to projected climate change in many species. This pattern was only significant under assumptions of unlimited dispersal, however, where considerable climate-driven habitat gains offset some concurrent climate-driven habitat losses. Additionally, some of the habitat gained with projected climate change overlapped with projected land use. Most species showed potential northern habitat expansion and southern habitat contraction due to projected climate change, resulting in sharply contrasting patterns of impact between Central and South Coast Ecoregions. In the Central Coast, dispersal could play an important role moderating losses from both climate change and land use. In contrast, high geographic overlap in habitat losses driven by projected climate change and projected land use in the South Coast underscores the potential for compounding negative impacts of both drivers. Limiting habitat conversion may be a broadly beneficial strategy under climate change. We emphasize the importance of addressing both drivers in conservation and resource management planning. PMID:24466116

  6. Using the Terrestrial Observation and Prediction System (TOPS) to Analyze Impacts of Climate Change on California Ecosystems

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

    The projected impacts of climate change on 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 were analyzed in this study. The impacts were analyzed using Special Report Emissions Scenarios (SRES) A1B and A2, maintaining present levels of urbanization constant and under projected urban expansion. The state data was separated into regions of similar climate, and watersheds of interest. A statistical analysis was completed for time series of temperature, precipitation, gross primary productivity (GPP), evapotranspiration, soil runoff, and vapor pressure deficit for the years 1950 through 2099. Trends produced from this analysis showed that increases in maximum and minimum temperatures lead to declines in peak GPP, length of growing seasons, and overall declines in runoff. However, changes in climate coupled with increases in impervious area due to intense urbanization are associated with an increase in winter runoff in scenario A2. The analysis is in support of the Climate Adaptation Science Investigation at NASA Ames Research Center, which is located within the Coyote Watershed of California. One result for this watershed shows that with projections of increased temperatures and increased urbanization there would be an extended dry summer season, which could threaten water availability. To counter this risk at NASA Ames Research Center, a study of the irrigation system was done to evaluate the amount of total water used for irrigation alone, and possible options for water conservation at the Center are considered to build a sustainable facility in a changing environment.

  7. Potential effects of acid deposition on aquatic ecosystems of the Sierra Nevada, California

    SciTech Connect

    Tonnessen, K.A.

    1983-01-01

    Acid deposition has been measured in California, including areas of the Sierra Nevada, during federal and state sponsored monitoring programs. The mountainous Sierra Nevada is characterized by low-alkalinity, granitic-basin lakes which may be sensitive to acid inputs, particularly during the snowmelt period. The field survey established that lakes located in subalpine basins on the western slope of the Sierra have circumneutral pH's, low alkalinities, and measureable dissolved concentrations of aluminum, iron, and manganese. Microcosm experiments, using 50-liter and 18-liter tanks containing unfiltered water and littoral sediments, were used to describe the behavior of trace metals on plankton populations following a single acid addition that lowered system pH to 4.0. The response of three different lakes varied with respect to changes in pH, alkalinity and carbon concentrations. Acidification effects were most severe for the high-elevation system with coarse-grained, gravelly sediments. During the experiment the acidified systems supported mats of filamentous-green algae, including Mougeotia spp. The data collected during this study have proven useful to decision makers within California in drafting legislation (Kapiloff Acid Deposition Act) authorizing a study of acid deposition, its effects, and possible control strategies.

  8. A: Coastal and Ocean Ecosystems Current Findings Linking Plume and Ocean Conditions to Salmon Growth and Survival

    E-print Network

    A: Coastal and Ocean Ecosystems ­ Current Findings Linking Plume and Ocean Conditions to Salmon conditions in the Pacific Northwest region were poor, and ocean survival of Columbia River salmon was significantly affected. New insights now demonstrate that variations in salmon abundance are linked to phenomena

  9. Background trends in California Current surface chlorophyll concentrations: A state-space view

    NASA Astrophysics Data System (ADS)

    Thomas, Andrew C.; Mendelssohn, Roy; Weatherbee, Ryan

    2013-10-01

    State-space models are applied to 13 years of monthly satellite-measured chlorophyll concentrations of the California Current, from British Columbia to Baja California, to isolate the slowly varying background trend from potentially nonstationary seasonal cycles, other higher-frequency cyclical variability, and an irregular plus measurement error signal. Temporal patterns in resulting background trends cluster into four dominant groups, three of which have increasing trends, the strongest of which extends over the coastal upwelling region from southern Oregon to Point Conception, California, and has a mean of 0.118 mg CHL m-3 decade-1. Overall, statistically significant increasing trends are observed over 75% of the study area, 20% of the study area had no trend, and 5% showed decreasing chlorophyll. Location-specific trend estimation shows increases are strongest (> 0.2 mg CHL m-3 decade-1) in upwelling areas along the Washington, Oregon and central California coasts, weaker in regions > 200 km offshore, and that positive trends are statistically significant over most of the California Current north of ˜27°N. Negative trends are evident south of ˜31°N off Baja California. These trends remain significant with similar spatial pattern, but lower magnitude, when the 1997-1998 El Niño period is removed from the analysis. State-space models of trends in alongshore wind stress and sea surface temperature over the same period indicate that local mechanisms linked to these chlorophyll trends are not clear. Comparisons of the chlorophyll trends to nonlocal signals, characterized by the North Pacific Gyre Oscillation and the Multivariate El Niño Index, map the spatially varying ecological footprint of these basin-scale signals.

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

    SciTech Connect

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

    1995-09-01

    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.

  11. Effects of sewage discharge on trophic state and water quality in a coastal ecosystem of the Gulf of California.

    PubMed

    Vargas-González, Héctor Hugo; Arreola-Lizárraga, José Alfredo; Mendoza-Salgado, Renato Arturo; Méndez-Rodríguez, Lía Celina; Lechuga-Deveze, Carlos Hernando; Padilla-Arredondo, Gustavo; Cordoba-Matson, Miguel

    2014-01-01

    This paper provides evidence of the effects of urban wastewater discharges on the trophic state and environmental quality of a coastal water body in a semiarid subtropical region in the Gulf of California. The concentrations of dissolved inorganic nutrients and organic matter from urban wastewater primary treatment were estimated. La Salada Cove was the receiving water body and parameters measured during an annual cycle were temperature, salinity, dissolved oxygen, nitrite, nitrate, ammonia, orthophosphate, and chlorophyll a. The effects of sewage inputs were determined by using Trophic State Index (TRIX) and the Arid Zone Coastal Water Quality Index (AZCI). It was observed that urban wastewater of the city of Guaymas provided 1,237 ton N yr(-1) and 811 ton P yr(-1) and TRIX indicated that the receiving water body showed symptoms of eutrophication from an oligotrophic state to a mesotrophic state; AZCI also indicated that the environmental quality of the water body was poor. The effects of urban wastewater supply with insufficient treatment resulted in symptoms of eutrophication and loss of ecological functions and services of the coastal ecosystem in La Salada Cove. PMID:24711731

  12. An adaptive, comprehensive monitoring strategy for chemicals of emerging concern (CECs) in California's Aquatic Ecosystems.

    PubMed

    Maruya, Keith A; Schlenk, Daniel; Anderson, Paul D; Denslow, Nancy D; Drewes, Jörg E; Olivieri, Adam W; Scott, Geoffrey I; Snyder, Shane A

    2014-01-01

    A scientific advisory panel was convened by the State of California to recommend monitoring for chemicals of emerging concern (CECs) in aquatic systems that receive discharge of municipal wastewater treatment plant (WWTP) effluent and stormwater runoff. The panel developed a risk-based screening framework that considered environmental sources and fate of CECs observed in receiving waters across the State. Using existing occurrence and risk threshold data in water, sediment, and biological tissue, the panel applied the framework to identify a priority list of CECs for initial monitoring in three representative receiving water scenarios. The initial screening list of 16 CECs identified by the panel included consumer and commercial chemicals, flame retardants, pesticides, pharmaceuticals and personal care products, and natural hormones. The panel designed an iterative, phased strategy with interpretive guidelines that direct and update management actions commensurate with potential risk identified using the risk-based framework and monitoring data. Because of the ever-changing nature of chemical use, technology, and management practices, the panel offered recommendations to improve CEC monitoring, including development of bioanalytical screening methods whose responses integrate exposure to complex mixtures and that can be linked to higher-order effects; development or refinement of models that predict the input, fate, and effects of future chemicals; and filling of key data gaps on CEC occurrence and toxicity. Finally, the panel stressed the need for adaptive management, allowing for future review of, and if warranted, modifications to the strategy to incorporate the latest science available to the water resources community. PMID:24129960

  13. Seasonal and nonseasonal variability of satellite-derived surface pigment concentration in the California Current

    NASA Technical Reports Server (NTRS)

    Strub, P. Ted; James, Corinne; Thomas, Andrew C.; Abbott, Mark R.

    1990-01-01

    The large-scale patterns of satellite-derived surface pigment concentration off the west coast of North America are presented and are averaged into monthly mean surface wind fields over the California Current system (CCS) for the July 1979 to June 1986 period. The patterns are discussed in terms of both seasonal and nonseasonal variability for the indicated time period. The large-scale seasonal characteristics of the California Current are summarized. The data and methods used are described, and the problems known to affect the satellite-derived pigment concentrations and the wind data used in the study are discussed. The statistical analysis results are then presented and discussed in light of past observations and theory. Details of the CZCS data processing are described, and details of the principal estimator pattern methodology used here are given.

  14. Current California legislative and regulatory activity impacting geothermal hydrothermal commercialization: monitoring report No. 2. Report No. 1020

    SciTech Connect

    Not Available

    1980-04-20

    The progress of four bills relating to geothermal energy is reported. The current regulatory activities of the California Energy Commission, the Lake County Planning Commission/Lake County Air Pollution Control District, the Governor's Office of Planning and Research, the State Lands' Commission, and the California Public Utilities Commission are reviewed. (MHR)

  15. Observations of planktonic bioluminescence in the euphotic zone of the California Current

    Microsoft Academic Search

    P. R. Greenblatt; D. F. Feng; A. Zirino; J. R. Losee

    1984-01-01

    The distributions of bioluminescence, temperature, salinity, oxygen. pH, and chlorophyll a were measured at 10 m intervals, to a depth of 100 m at a station (33°46'N; 119°36'W) in the California Current from 17 to 20 July 1982. The distribution of bioluminescence showed a marked day-night change which was consistent over the sampling period. The nighttime maximum was at the

  16. 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

  17. Pattern and persistence of a nearshore planktonic ecosystem off Southern California

    NASA Astrophysics Data System (ADS)

    Barnett, Arthur M.; Jahn, Andrew E.

    1987-01-01

    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, three—the copepods Acartia clausi and Oithona oculata, and barnacle larvae—had 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.

  18. Integrated climate/land use/hydrological change scenarios for assessing threats to ecosystem services on California rangelands

    NASA Astrophysics Data System (ADS)

    Byrd, K. B.; Flint, L. E.; Casey, C. F.; Alvarez, P.; Sleeter, B. M.; Sohl, T.

    2013-12-01

    In California there are over 18 million acres of rangelands in the Central Valley and the interior Coast Range, most of which are privately owned and managed for livestock production. Ranches provide extensive wildlife habitat and generate multiple ecosystem services that carry considerable market and non-market values. These rangelands are under pressure from urbanization and conversion to intensive agriculture, as well as from climate change that can alter the flow of these services. To understand the coupled and isolated impacts of land use and climate change on rangeland ecosystem services, we developed six spatially explicit (250 m) coupled climate/land use/hydrological change scenarios for the Central Valley and oak woodland regions of California consistent with three IPCC emission scenarios - A2, A1B and B1. Three land use land cover (LULC) change scenarios were each integrated with two downscaled global climate models (GCMs) (a warm, wet future and a hot, dry future) and related hydrologic data. We used these scenarios to quantify wildlife habitat, water supply (recharge potential and streamflow) and carbon sequestration on rangelands and to conduct an economic analysis associated with changes in these benefits. The USGS FOREcasting SCEnarios of land-use change model (FORE-SCE), which runs dynamically with downscaled GCM outputs, was used to generate maps of yearly LULC change for each scenario from 2006 to 2100. We used the USGS Basin Characterization Model (BCM), a regional water balance model, to generate change in runoff, recharge, and stream discharge based on land use change and climate change. Metrics derived from model outputs were generated at the landscape scale and for six case-study watersheds. At the landscape scale, over a quarter of the million acres set aside for conservation in the B1 scenario would otherwise be converted to agriculture in the A2 scenario, where temperatures increase by up to 4.5 °C compared to 1.3 °C in the B1 scenario. A comparison of two watersheds - Alameda Creek, an urbanized watershed, and Upper Stony Creek, impacted by intensified agriculture, demonstrates the relative contribution of urbanization and climate change to water supply. In Upper Stony Creek, where 24% of grassland is converted to agriculture in the A1B scenario, a hotter, dryer 4-year time period could lead to a 40% reduction in streamflow compared to present day. In Alameda Creek, for the same scenario, 47% of grassland is converted to urbanized lands and streamflow may increase by 11%, resulting in a recharge:runoff ratio of 0.26; though if urbanization does not take place, streamflow could decrease by 64% and the recharge:runoff ratio would be 1.2. Model outputs quantify the impact of urbanization on water supply and show the importance of soil storage capacity. Scenarios have applications for climate-smart conservation and land use planning by identifying outcomes associated with coupled future land use scenarios and more variable and extreme potential future climates.

  19. Litterfall dynamics and nutrient decomposition of arid mangroves in the Gulf of California: Their role sustaining ecosystem heterotrophy

    NASA Astrophysics Data System (ADS)

    Sánchez-Andrés, R.; Sánchez-Carrillo, S.; Alatorre, L. C.; Cirujano, S.; Álvarez-Cobelas, M.

    2010-10-01

    This study shows results on litterfall dynamics and decay in mangrove stands of Avicennia germinans distributed along a latitudinal gradient (three forest sites) in the Gulf of California, in order to assess whether internal sources could support the observed mangrove ecosystem organic deficit in this arid tropic. Total mean annual litterfall production increased southward (712.6 ± 53.3, 1501.3 ± 145.1 and 1506.2 ± 280.5 g DW m -2 y -1, in the Yaqui, Mayo and Fuerte areas respectively), leaves being the main component of litter in all locations during the entire year, followed by fruits. The wet season (June-September) showed the highest litterfall rates through fruits. The temporal trend of litterfall production was significantly explained through mean air temperature ( R2 = 68%) whilst total annual litter production in the entire region showed a statistically significant relationship with total soil phosphorus, salinity, total nitrogen, organic matter and tree height ( R2 = 0.67). Throughout 117 days of the decomposition experiment, the litter lost 50% of its original dry weight in 5.8 days (average decay rate of 0.032 ± 0.04 g DW d -1) and there were not significant differences in the remaining mass after 6 days. The percentage of both C and P released from the litter correlated significantly with the ratio of tidal inundated days to total experiment days ( R2 = 0.62, p = 0.03 and R2 = 0.67, p = 0.02, respectively); however, the frequency of tidal inundation only showed a significant increase in C release from Avicennia litter after 6 and above 48 days of decomposition. Whereas the total C content of litter bags decreased linearly over the decomposition to (% Total C = 5.52 - 0.46 days, R2 = 0.81, p = 0.0005), N content displayed an irregular pattern with a significant increase of decay between 48 and 76 days from the beginning of the experiment. The pattern for relative P content of litter revealed reductions of up to 99% of the original (%tot- P = -9.77 to 1.004 days, R2 = 0.72, p = 0.01) although most of the P reduction occurred between 17 and 34 days after the experiment started. Soil N and P contents, which exhibited significant differences in the course of the decomposition experiment, appeared to show significant differences between sampling sites, although they were not related to tidal influence, nor by leaf and nutrient leaching. In a global basis, C/ N litter ratios decreased linearly ( C/ N = 32.86 - 0.1006 days, R2 = 0.62, p = 0.02), showing a strong and significant correlation with meteorological variables ( R2 = 0.99, p = 0.01). C/ P ratios of litter increased through an exponential function ( C/ P = 119.35e 0.04day, R2 = 0.89, p < 0.001). Changes in the remaining percentage of litter mass during the experiment were significantly correlated with soil C/ N ratio ( R2 = 0.56, p = 0.03) as well as with the soil C/ P ratio ( R2 = 0.98, p < 0.001). Our results of litter decomposition dynamics in this mangrove support the fact of null net primary productivity of the arid mangrove wetlands: fast litter decomposition compensates the ecosystem organic deficit in order to sustain the mangrove productivity. Litter decomposition plays a key role in the ecosystem metabolism in mangroves of arid tropics.

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

    NASA Astrophysics Data System (ADS)

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

    2012-12-01

    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.

  1. Microbial indicators of aquatic ecosystem change: current applications to eutrophication studies.

    PubMed

    Paerl, Hans W; Dyble, Julianne; Moisander, Pia H; Noble, Rachel T; Piehler, Michael F; Pinckney, James L; Steppe, Timothy F; Twomey, Luke; Valdes, Lexia M

    2003-12-01

    Human encroachment on aquatic ecosystems is increasing at an unprecedented rate. The impacts of human pollution and habitat alteration are most evident and of greatest concern at the microbial level, where a bulk of production and nutrient cycling takes place. Aquatic ecosystems are additionally affected by natural perturbations, including droughts, storms, and floods, the frequency and extent of which may be increasing. Distinguishing and integrating the impacts of natural and human stressors is essential for understanding environmentally driven change of microbial diversity and function. Microbial bioindicators play a major role in detecting and characterizing these changes. Complementary use of analytical and molecular indicator tools shows great promise in helping us clarify the processes underlying microbial population, community, and ecosystem change in response to environmental perturbations. This is illustrated in phytoplankton (microalgal and cyanobacterial) and bacterial community changes in a range of US estuarine and coastal ecosystems experiencing increasing development in their water- and airsheds as well as climatic changes (e.g., increasing hurricane frequency). Microbial indicators can be adapted to a range of monitoring programs, including ferries, moored instrumentation, and remote sensing, in order to evaluate environmental controls on microbial community structure and function over ecosystem to global scales. PMID:19719555

  2. Biochemical and molecular indicators in aquatic ecosystems: Current status and further applications in Malaysia

    Microsoft Academic Search

    S. G. Tan; C. K. Yap

    2006-01-01

    Malaysia's aquatic ecosystems contribute 1.6% of her gross domestic product and provide employment to about 100,000 people. They are sources of a significant proportion of the nation's food supply, mainly by marine capture fisheries; but aquaculture, both marine and freshwater is becoming increasingly important. Hence, characterization of the species diversity of Malaysian biological resources (bioresources) is of paramount importance. One

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

    Microsoft Academic Search

    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. Setälä; A. J. Symstad; J. Vandermeer; D. A. Wardle

    2005-01-01

    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

  4. MICROBIAL INDICATORS OF AQUATIC ECOSYSTEM CHANGE: CURRENT APPLICATIONS TO EUTROPHICATION STUDIES. (R828677C001)

    EPA Science Inventory

    Human encroachment on aquatic ecosystems is increasing at an unprecedented rate. The impacts of human pollution and habitat alteration are most evident and of greatest concern at the microbial level, where a bulk of production and nutrient cycling takes place. Aquatic ecosyste...

  5. Seasonal and interannual variability of pigment concentrations across a California Current frontal zone

    NASA Technical Reports Server (NTRS)

    Thomas, A. C.; Strub, P. T.

    1990-01-01

    The seasonal and interannual variability of the latitudinal position of the California Current frontal zone was investigated by examining satellite images of phytoplankton pigment from the coastal-zone color scanner for the periods 1979-1983 and 1986. The pigment concentrations associated with the zonal front were also determined. A general seasonal cycle of pigment concentrations is was established. It was found that variations in the frontal structure are controlled primarily by changes in pigment concentration north of the front. Seasonal variations were found to be minimal south of the front, where pigment concentrations remain low throughout the spring, summer, and fall.

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

    Microsoft Academic Search

    OA Barocio-León; R Millán-Núñez; E Santamaría-del-Ángel; A González-Silvera

    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

  7. Current stage of the restoration of Chernozems in rangeland ecosystems of the steppe zone

    NASA Astrophysics Data System (ADS)

    Rusanov, A. M.

    2015-06-01

    The results of two rounds of soil and geobotanic surveys of rangeland ecosystems in the steppe zone are presented. The same sites with southern chernozems (Calcic Chernozems) under steppe plant communities at different stages of pasture degradation were investigated at the end of the 1980s, when they suffered maximum anthropogenic loads, and in 2011-2013, after a long period of relative rest. In the 1980s, degradation of soil physical properties in rangeland ecosystems under the impact of long-term unsustainable management was noted. At the same time, it was found that the major qualitative and quantitative properties of humus in the chernozems were preserved independently from the level of pasture degradation. The following period of moderate grazing pressure had a favorable effect on the soil properties. Owing to the good characteristics of the soil humus, the restoration of the physical properties of chernozems-including their structural state, water permeability, and bulk density-took place in a relatively short period. It is argued that the soil bulk density is a natural regulator of the species composition of steppe vegetation, because true grasses (Poaceae)-typical representatives of the steppe flora-have a fibrous root system requiring the soils with low density values. The improvement of the properties of chernozems is related to the development of secondary ecosystems with a higher portion of grasses in place of damaged rangelands and to the increase in the area of nominal virgin phytocenoses.

  8. Multi-Objective Analysis for Ecosystem Reconciliation on an Engineered Floodplain: The Yolo Bypass in California's Central Valley

    E-print Network

    Pasternack, Gregory B.

    i Multi-Objective Analysis for Ecosystem Reconciliation on an Engineered Floodplain: The Yolo. Suddeth September 2014 Hydrologic Sciences Using Multi-Objective Analysis for Ecosystem Reconciliation INTRODUCTION This study presents a multi-objective analysis for balancing ecological goals with human uses

  9. Trophic modeling of the Northern Humboldt Current Ecosystem, Part I: Comparing trophic linkages under La Niña and El Niño conditions

    NASA Astrophysics Data System (ADS)

    Tam, Jorge; Taylor, Marc H.; Blaskovic, Verónica; Espinoza, Pepe; Michael Ballón, R.; Díaz, Erich; Wosnitza-Mendo, Claudia; Argüelles, Juan; Purca, Sara; Ayón, Patricia; Quipuzcoa, Luis; Gutiérrez, Dimitri; Goya, Elisa; Ochoa, Noemí; Wolff, Matthias

    2008-10-01

    The El Niño of 1997-98 was one of the strongest warming events of the past century; among many other effects, it impacted phytoplankton along the Peruvian coast by changing species composition and reducing biomass. While responses of the main fish resources to this natural perturbation are relatively well known, understanding the ecosystem response as a whole requires an ecotrophic multispecies approach. In this work, we construct trophic models of the Northern Humboldt Current Ecosystem (NHCE) and compare the La Niña (LN) years in 1995-96 with the El Niño (EN) years in 1997-98. The model area extends from 4°S-16°S and to 60 nm from the coast. The model consists of 32 functional groups of organisms and differs from previous trophic models of the Peruvian system through: (i) division of plankton into size classes to account for EN-associated changes and feeding preferences of small pelagic fish, (ii) increased division of demersal groups and separation of life history stages of hake, (iii) inclusion of mesopelagic fish, and (iv) incorporation of the jumbo squid ( Dosidicus gigas), which became abundant following EN. Results show that EN reduced the size and organization of energy flows of the NHCE, but the overall functioning (proportion of energy flows used for respiration, consumption by predators, detritus and export) of the ecosystem was maintained. The reduction of diatom biomass during EN forced omnivorous planktivorous fish to switch to a more zooplankton-dominated diet, raising their trophic level. Consequently, in the EN model the trophic level increased for several predatory groups (mackerel, other large pelagics, sea birds, pinnipeds) and for fishery catch. A high modeled biomass of macrozooplankton was needed to balance the consumption by planktivores, especially during EN condition when observed diatoms biomass diminished dramatically. Despite overall lower planktivorous fish catches, the higher primary production required-to-catch ratio implied a stronger ecological impact of the fishery and stresses the need for precautionary management of fisheries during and after EN. During EN energetic indicators such as the lower primary production/total biomass ratio suggest a more energetically efficient ecosystem, while reduced network indicators such as the cycling index and relative ascendency indicate of a less organized state of the ecosystem. Compared to previous trophic models of the NHCE we observed: (i) a shrinking of ecosystem size in term of energy flows, (ii) slight changes in overall functioning (proportion of energy flows used for respiration, consumption by predators and detritus), and (iii) the use of alternate pathways leading to a higher ecological impact of the fishery for planktivorous fish.

  10. Ecosystem consequences of changing inputs of terrestrial dissolved organic matter to lakes: current knowledge and future challenges

    USGS Publications Warehouse

    Solomon, Christopher T.; Jones, Stuart E.; Weidel, Brian C.; Buffam, Ishi; Fork, Megan L; Karlsson, Jan; Larsen, Soren; Lennon, Jay T.; Read, Jordan S.; Sadro, Steven; Saros, Jasmine E.

    2015-01-01

    Lake ecosystems and the services that they provide to people are profoundly influenced by dissolved organic matter derived from terrestrial plant tissues. These terrestrial dissolved organic matter (tDOM) inputs to lakes have changed substantially in recent decades, and will likely continue to change. In this paper, we first briefly review the substantial literature describing tDOM effects on lakes and ongoing changes in tDOM inputs. We then identify and provide examples of four major challenges which limit predictions about the implications of tDOM change for lakes, as follows: First, it is currently difficult to forecast future tDOM inputs for particular lakes or lake regions. Second, tDOM influences ecosystems via complex, interacting, physical-chemical-biological effects and our holistic understanding of those effects is still rudimentary. Third, non-linearities and thresholds in relationships between tDOM inputs and ecosystem processes have not been well described. Fourth, much understanding of tDOM effects is built on comparative studies across space that may not capture likely responses through time. We conclude by identifying research approaches that may be important for overcoming those challenges in order to provide policy- and management-relevant predictions about the implications of changing tDOM inputs for lakes.

  11. The deepening of the wind-mixed layer in the southern part of the California Current

    NASA Astrophysics Data System (ADS)

    Gomez-Valdes, J.; Jeronimo, G.

    2009-12-01

    Predictions of mixed layer depth (MLD) are regularly made using ocean general circulation models, although simple models are also useful tools in several situations. In this study, we report that Pollard, Rhines and Thompson (PRT) one-dimensional model shows considerable capability in reproducing the MLD annual cycle in the coastal and transition domains of the southern part of the California Current (24-32°N). MLD is predicted from PRT model as Au*/?Nf, where u* is shear velocity, N is buoyancy frequency and f is Coriolis parameter. Satellite-derived data (QuickScat) are used to calculate the shear velocity term. The hindcast study is applied to a decade (1997-2008) of conductivity-temperature-depth observations collected by quarterly survey cruises under supervision of Mexican Investigations of the California Current (IMECOCAL) program. Seasonal MLD observed values are obtained using a potential density criterion with an error of ± 3 m. The range of difference between model and observed values is between 2 and 7 m; the largest significant discrepancy occurs at the middle of the IMECOCAL domain during winter (January). Modeling results are consistent with a balance between surface heat flux and wind-driven offshore heat flux estimated from our dataset.

  12. Current Status of Western Yellow-Billed Cuckoo along the Sacramento and Feather Rivers, California

    PubMed Central

    2015-01-01

    To evaluate the current status of the western population of the Yellow-billed Cuckoo (Coccyzus americanus) along the Sacramento and Feather rivers in California’s Sacramento Valley, we conducted extensive call playback surveys in 2012 and 2013. We also quantified the amount and distribution of potential habitat. Our survey transects were randomly located and spatially balanced to sample representative areas of the potential habitat. We estimated that the total area of potential habitat was 8,134 ha along the Sacramento River and 2,052 ha along the Feather River, for a total of 10,186 ha. Large-scale restoration efforts have created potential habitat along both of these rivers. Despite this increase in the amount of habitat, the number of cuckoos we detected was extremely low. There were 8 detection occasions in 2012 and 10 occasions in 2013 on the Sacramento River, in both restored and remnant habitat. We had no detections on the Feather River in either year. We compared our results to 10 historic studies from as far back as 1972 and found that the Yellow-billed Cuckoo had unprecedentedly low numbers in 2010, 2012, and 2013. The current limiting factor for the Yellow-billed Cuckoo in the Sacramento Valley is likely not the amount of appropriate vegetation, as restoration has created more habitat over the last 30 years. Reasons for the cuckoo decline on the Sacramento and Feather rivers are unclear. PMID:25915801

  13. Speculations on processes responsible for mesoscale current lineations on the continental shelf, southern California

    USGS Publications Warehouse

    Karl, Herman A.

    1980-01-01

    A side-scan sonar survey of San Pedro shelf, California, reveals areas of mesoscale current lineations oriented approximately north-northeast in water depths of 20-25 m. Widths of sand ribbons range from 40 to 120 m and intervening erosional furrows, from 15 to 50 m. A conceptual model shows that the scale and orientation of current lineations agree with the dimensions and axial directions of Langmuir circulations theoretically generated by a combination either of southerly and southwesterly winds with regular trains of swell from the southern hemisphere or of two sets of wave trains crossing from the south and west. These longitudinal bedforms indicate shore-normal sediment transport at the times and on the areas of the shelf when and where they have been observed.

  14. Invasive Plant-Soil Feedbacks and Ecosystem Resistance and Resilience: A Comparison of Three Vegetation Types in California

    E-print Network

    Dickens, Sara Jo Myrtle

    2010-01-01

    soil microbial communities, and ecosystem function: Are there any links? Ecologymicrobial community structure and function in the soil. EcologySoil microbial community associated with an invasive grass differentially impacts native plant performance. Microbial Ecology

  15. Interannual variability in the Northern California Current food web structure: Changes in energy flow pathways and the role of forage fish, euphausiids, and jellyfish

    NASA Astrophysics Data System (ADS)

    Ruzicka, James J.; Brodeur, Richard D.; Emmett, Robert L.; Steele, John H.; Zamon, Jeannette E.; Morgan, Cheryl A.; Thomas, Andrew C.; Wainwright, Thomas C.

    2012-09-01

    The Northern California Current (NCC) is a seasonally productive and open ecosystem. It is home to both a diverse endemic community and to seasonally transient species. Productivity and food web structure vary seasonally, interannually, and decadally due to variability in coastal upwelling, climate-scale physical processes, and the migratory species entering the system. The composition of the pelagic community varies between years, including changes to mid-trophic level groups that represent alternate energy-transfer pathways between lower and upper trophic levels (forage fishes, euphausiids, jellyfish). Multiple data sets, including annual spring and summer mesoscale surveys of the zooplankton, pelagic fish, and seabird communities, were used to infer NCC trophic network arrangements and develop end-to-end models for each of the 2003-2007 upwelling seasons. Each model was used to quantify the interannual variability in energy-transfer efficiency from bottom to top trophic levels. When each model was driven under an identical nutrient input rate, substantial differences in the energy available to each functional group were evident. Scenario analyses were used to examine the roles of forage fishes, euphausiids, and jellyfish (small gelatinous zooplankton and large carnivorous jellyfish) as alternate energy transfer pathways. Euphausiids were the more important energy transfer pathway; a large proportion of the lower trophic production consumed was transferred to higher trophic levels. In contrast, jellyfish acted as a production loss pathway; little of the production consumed was passed upwards. Analysis of the range of ecosystem states observed interannually and understanding system sensitivity to variability among key trophic groups improves our ability to predict NCC ecosystem response to short- and long-term environmental change.

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

    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.

  17. /sup 234/Th: /sup 238/U disequilibria within the California Current

    SciTech Connect

    Coale, K.H.; Bruland, K.W.

    1985-01-01

    Profiles of dissolved and particulate /sup 234/Th were determined at several stations within the California Current. Modeling of the disequilibria between the /sup 234/Th and /sup 238/U within the surface waters provides for estimates of the residence time of dissolved thorium with respect to particle scavenging, the particle residence time, and the particulate /sup 234/Th flux exiting the surface layer. The model-derived, first-order scavenging rate constant for dissolved thorium is observed to be proportional to the rate of primary production. Particle residence times seem to be governed by the rate of zooplankton grazing and the types of zooplankton present. Model-derived particulate /sup 234/Th fluxes are in good agreement with direct measurements by sediment traps.

  18. Dynamic variability of biogeochemical ratios in the Southern California Current System

    NASA Astrophysics Data System (ADS)

    Martz, Todd; Send, Uwe; Ohman, Mark D.; Takeshita, Yuichiro; Bresnahan, Philip; Kim, Hey-Jin; Nam, SungHyun

    2014-04-01

    We use autonomous nitrate (NO3-), oxygen (O2), and dissolved inorganic carbon (DIC) observations to examine the relationship between ratios of C:N:O at an upwelling site in the Southern California Current System. Mean ratios and 95% confidence intervals observed by sensors over 8 months were NO3-:O2 = -0.11 ± 0.002, NO3-:DIC = 0.14 ± 0.001, and DIC:O2 = -0.83 ± 0.01, in good agreement with Redfield ratios. Variability in the ratios on the weekly time scale is attributable to shifts in biological demand and nutrient availability and shown to exhibit a spectrum of values ranging from near 100% New Production to 100% Regenerated Production.

  19. Multi-satellite time series of inherent optical properties in the California Current

    NASA Astrophysics Data System (ADS)

    Kahru, Mati; Lee, Zhongping; Kudela, Raphael M.; Manzano-Sarabia, Marlenne; Greg Mitchell, B.

    2015-02-01

    Satellite ocean color radiometry is a powerful method to study ocean biology but the relationships between satellite measurements and the in situ ocean properties are not well understood. Moreover, the measurements made with one satellite sensor may not be directly compatible with similar measurements from another sensor. We estimate inherent optical properties (IOPs) in the California Current by applying empirically optimized versions of the Quasi-Analytical Algorithm (QAA) of Lee et al. (2002) to satellite remote sensing reflectance (Rrs) from four ocean color sensors (OCTS, SeaWiFS, MODISA and MERIS). The set of estimated IOPs includes the total absorption coefficient at 490 nm (a490), phytoplankton absorption coefficient at 440 nm (aph440), absorption by dissolved and detrital organic matter at 440 nm (adg440) and particle backscattering coefficient at 490 nm (bbp490). The empirical inversion models are created by minimizing the deviations between satellite match-ups with in situ measurements and between the estimates of individual overlapping satellite sensors. The derived empirical algorithms were then applied to satellite Level-3 daily Rrs to create merged multi-sensor time series of the near-surface optical characteristics in the California Current region for a time period of over 16 years (November 1996-December 2012). Due to the limited number of in situ match-ups and their uneven distribution as well as the large errors in the satellite-derived Rrs, the uncertainty in the retrieved IOPs is still significant and difficult to quantify. The merged time series show the dominant annual cycle but also significant variability at interannual time scales. The ratio of adg440 to aph440 is around 1 in the transition zone, is >1 in the coastal zone and generally <1 offshore. adg440 decreases towards south and towards offshore. The long-term (~16 years) trend in aph440, representative of phytoplankton biomass, shows a significant (P<0.01) increasing trend in a wide band (~500 km) along the coast and a significant decreasing trends in the oligotrophic North Pacific gyre. The trend of increasing aph440 in the upwelling areas off California is positively correlated with the increasing wind speed along the coast.

  20. Current and suspended sediment measurements on the central California continental shelf

    SciTech Connect

    Sherwood, C.R.; Coats, D.; Walls, B. (Battelle/Marine Sciences Lab., Sequim, WA (USA); Marine Research Specialists, Ventura, CA (USA); Corps of Engineers, San Francisco, CA (USA). San Francisco District)

    1989-09-01

    The US Army Corps of Engineers, San Francisco District (USACE), is evaluating the suitability of sites for ocean disposal of dredged material from several projects in the San Francisco Bay area. In conjunction with those efforts, the USACE maintained current meter moorings at two candidate disposal sites (Sites B1B and 1M) on the California continental shelf. Optical backscatterance (OBS) sensors mounted on these moorings near the sea bed were used to determine suspended sediment concentrations. The initial deployments at Site 1M (42 m) and Site B1B (86 m) occurred in April 1988; data were recovered in June and September 1988, and January 1989. Final instrument recovery was scheduled for May 1989, and the program should provide a full year of information on tidal and low-frequency shelf currents and near-bed suspended sediment concentrations. This is a preliminary report of the data from the 86-m site. The data showed evidence of strong vertical coherence in the currents, net southward flow at all depths during upwelling season, frequent flow reversals in fall and winter, and more frequent resuspension of sediment during the winter months. 9 refs., 5 figs., 2 tabs.

  1. Characterizing changes in streamflow under historical and current climates for the Russian River, California

    NASA Astrophysics Data System (ADS)

    Curtis, J.; Flint, L. E.

    2014-12-01

    Precipitation in California is naturally more variable than elsewhere in the United States, and climate change is expected to increase the frequency and severity of precipitation and streamflow anomalies. As part of a larger effort to assess flow conditions under historical, current, and future climates, we characterized the change in the Russian River's mainstem flows between two 30-year periods that represent historical (1951 to 1980) and current (1981 to 2010) climate conditions. Analyses included measured data from one mainstem gage (Ukiah) that represents natural flow conditions, and three mainstem gages (Hopland, Healdsburg, and Guerneville) regulated by diversion into the Russian River from the adjacent Eel River and by reservoir storage. Analysis of natural flows at the Ukiah gage under the current climate indicates statistically significant increases in low flow metrics that include: median monthly flows from July to October; number of zero flow days; and 1-, 3-, 5-, 7-, 30- and 90-day minimum flows. In contrast to the Ukiah gage, decreases in low flows under the current climate at the three regulated-streamflow gages varied with distance downstream. Statistically significant declines in median monthly flows occurred during the second period (1981-2010) from August to November at Hopland, September to November at Healdsburg and in October at Guerneville. Although mean annual flow declined at all four gages during the second period and median monthly low flows declined at the downstream gages, median monthly low flows and minimum flows at the Ukiah gage which represents natural flows increased during the driest months (July to October). Results from this study will be used to support ecological studies and water resource planning within the Russian River watershed. The relative importance of climate and watershed response on the quality and quantity of streamflow under historical and current climates will be assessed and results compared to analyses of unimpaired flows estimated using a basin-scale water balance model calibrated to low flow conditions.

  2. Influences of the Juan de Fuca Eddy on circulation, nutrients, and phytoplankton production in the northern California Current System

    Microsoft Academic Search

    A. MacFadyen; B. M. Hickey; W. P. Cochlan

    2008-01-01

    A diagnostic circulation model and water mass analyses are used to examine variability in the structure and circulation of the Juan de Fuca Eddy, a highly productive region at the northern end of the California Current. Results from three years of field studies demonstrate that the eddy increases in spatial extent from early to late summer as the vertically averaged

  3. Moored observations of the current and temperature structure over the continental slope off central California 2. The energetics of the flow off Point Sur

    Microsoft Academic Search

    Timothy D. Tisch; Steven R. Ramp

    1997-01-01

    The data from two current meter moorings off Point Sur, California, were analyzed to examine the energy transfers over the continental slope in the California Current system (CCS). The method used was to calculate terms in the heat equation at intermediate depths between instruments, using the thermal wind relation to estimate the horizontal temperature gradients from the vertical shear. Time

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

    NASA Astrophysics Data System (ADS)

    Castelao, Renato M.; Wang, Yuntao

    2014-03-01

    Simultaneous 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.

  5. Quantifying radaition and energy balances at a heterogeneous oak savanna ecosystem in California: a three dimensional modeling appraoch

    NASA Astrophysics Data System (ADS)

    Kobayashi, H.; Baldocchi, D. D.; Ryu, Y.; Chen, Q.; Ma, S.; Osuna, J. L.; Ustin, S.

    2010-12-01

    Most land surface and ecosystem models assume that a vegetated canopy can be abstracted as a turbid medium when they compute mass, energy, and carbon exchange. Since savanna ecosystems are inherently complex and spatially heterogeneous, a turbid media models fail to simulate radiation environments at savanna ecosystems. In this study, we describe a three dimensional radiation budget model (Forest Light Environmental Simulator, FLiES) coupled with a soil and canopy energy balance and canopy physiology model (CANOAK). The model was able to simulate spatial and diurnal patterns of radiation properties both shortwave and longwave radiation as well as latent and sensible heat, and tree canopy photosynthesis. Explicit consideration of woody elements (branches and stems) is crucial for realistic computation of radiation environments in savanna ecosystems because of its nature of low LAI and a relatively high fraction of woody elements. We found that the heat storage term of woody elements could be non-negligible amount (12-17% of total net radiation). We found that all woodland components (tree leaves, understory grasses, woody materials, and the soil) cannot be negligible for modeling the radiation and energy balances as they all absorb a significant amount of the solar radiation.

  6. Sustainability of current agriculture practices, community perception, and implications for ecosystem health: an Indian study.

    PubMed

    Sarkar, Atanu; Patil, Shantagouda; Hugar, Lingappa B; vanLoon, Gary

    2011-12-01

    In order to support agribusiness and to attain food security for ever-increasing populations, most countries in the world have embraced modern agricultural technologies. Ecological consequences of the technocentric approaches, and their sustainability and impacts on human health have, however, not received adequate attention particularly in developing countries. India is one country that has undergone a rapid transformation in the field of agriculture by adopting strategies of the Green Revolution. This article provides a comparative analysis of the effects of older and newer paradigms of agricultural practices on ecosystem and human health within the larger context of sustainability. The study was conducted in three closely situated areas where different agricultural practices were followed: (a) the head-end of a modern canal-irrigated area, (b) an adjacent dryland, and (c) an area (the ancient area) that has been provided with irrigation for some 800 years. Data were collected by in-depth interviews of individual farmers, focus-group discussions, participatory observations, and from secondary sources. The dryland, receiving limited rainfall, continues to practice diverse cropping centered to a large extent on traditional coarse cereals and uses only small amounts of chemical inputs. On the other hand, modern agriculture in the head-end emphasizes continuous cropping of rice supported by extensive and indiscriminate use of agrochemicals. Market forces have, to a significant degree, influenced the ancient area to abandon much of its early practices of organic farming and to take up aspects of modern agricultural practice. Rice cultivation in the irrigated parts has changed the local landscape and vegetation and has augmented the mosquito population, which is a potential vector for malaria, Japanese encephalitis and other diseases. Nevertheless, despite these problems, perceptions of adverse environmental effects are lowest in the heavily irrigated area. PMID:22124700

  7. Transport patterns of Pacific sardine Sardinops sagax eggs and larvae in the California Current System

    NASA Astrophysics Data System (ADS)

    Weber, Edward D.; Chao, Yi; Chai, Fei; McClatchie, Sam

    2015-06-01

    We simulated transport of Pacific sardine eggs captured offshore of California in spring of 2001-2012 using a regional ocean circulation model. Eggs were assumed to have developed into larvae within a few days and were modeled using five behavioral patterns: passive transport, diel vertical migration, diel vertical migration combined with swimming against the current, diel migration combined with migration toward shore, and diel migration combined with migration toward the best habitat. Simulated larvae with no swimming behavior were advected far offshore to poor habitat where they were unlikely to survive. Diel vertical migration resulted in less offshore transport because larvae were less affected by surface currents during the day. However, in half the years simulated nearly all juveniles were also located in poor habitat by late summer in this scenario. Swimming against the current combined with diel vertical migration resulted in similar transport patterns to the diel-vertical-migration scenario because currents dominated the transport of eggs and small larvae during the spring and early summer. Migration toward shore resulted in a large fraction of juveniles being located in appropriate habitat during late summer in all years. Migration toward the best habitat was the best strategy modeled. This strategy resulted in a slightly greater proportion of larvae being located in appropriate habitat at the end of summer than the swimming-toward-shore scenario, despite the fact that most larvae were located farther offshore. These results suggest that larval sardine might use directed horizontal swimming behavior to remain in suitable habitat conditions. A large fraction of larvae were transported south into Mexican waters by late summer in all five scenarios. Surveying juvenile sardines in fall near the border of the U.S. and Mexico may be an efficient means of estimating recruitment because the advection pattern of eggs and larvae to the south is opposite the adult migration pattern to the north. This pattern may cause juveniles to be spatially segregated from adults at the time they are being recruited.

  8. Mercury in the Walker River Basin, Nevada and California--sources, distribution, and potential effects on the ecosystem

    USGS Publications Warehouse

    Seiler, Ralph L.; Lico, Michael S.; Wiemeyer Evers, David C.

    2004-01-01

    Mercury is one of the most serious contaminants of water, sediment, and biota in Nevada because of its use during 19th century mining activities to recover gold and silver from ores. In 1998, mercury problems were discovered in the Walker River Basin of California and Nevada when blood drawn from three common loons from Walker Lake was analyzed and found to have severely elevated mercury levels. From 1999 to 2001, the U.S. Geological Survey and the U.S. Fish and Wildlife Service collected water, sediment, and biological samples to determine mercury sources, distribution, and potential effects on the Walker River Basin ecosystem. Total-mercury concentrations ranged from 0.62 to 57.11 ng/L in streams from the Walker River system and ranged from 1.02 to 26.8 ng/L in lakes and reservoirs. Total-mercury concentrations in streambed sediment ranged from 1 to 13,600 ng/g, and methylmercury concentrations ranged from 0.07 to 32.1 ng/g. The sediment-effects threshold for mercury for fresh-water invertebrates is 200 ng/g, which was exceeded at nine stream sites in the Walker River Basin. The highest mercury concentrations were in streams with historic mines and milling operations in the watershed. The highest mercury concentration in sediment, 13,600 ng/g, was found in Bodie Creek near Bodie, Calif., a site of extensive gold mining and milling activities during the 19th century. Sediment cores taken from Walker Lake show total-mercury concentrations exceeding 1,000 ng/g at depths greater than 15 cm below lake bottom. The presence of 137Cs above 8 cm in one core indicates that the upper 8 cm was deposited sometime after 1963. The mercury peak at 46 cm in that core, 2,660 ng/g, likely represents the peak of mining and gold extraction in the Bodie and Aurora mining districts between 1870 and 1880. Mercury concentrations in aquatic invertebrates at all sites downstream from mining activities in the Rough Creek watershed, which drains the Bodie and Aurora mining districts, were elevated (range 0.263 to 0.863 ?g/g, dry weight). Mercury concentrations in the Walker Lake tui chub, the most abundant and likely prey for common loons, ranged from approximately 0.09 ?g/g to approximately 0.9 ?g/g (wet weight). Larger tui chub in the lake, which are most likely older, had the highest mercury concentrations. Blood samples from 94 common loons collected at Walker Lake between 1998 and 2001 contained a mean mercury concentration of 2.96 ?g/g (standard deviation 1.72 ?g/g). These levels were substantially higher than those found in more than 1,600 common loons tested across North America. Among the 1,600 common loons, the greatest blood mercury concentration, 9.46 ?g/g, was from a loon at Walker Lake. According to risk assessments for northeastern North America, blood mercury concentrations exceeding 3.0 ?g/g cause behavioral, reproductive, and physiological effects. At least 52 percent of the loons at Walker Lake are at risk for adverse effects from mercury on the basis of their blood-mercury concentrations. The larger loons staging in the spring are the most at risk group. The elevated mercury levels found in tui chub and common loons indicate that there is a potential threat to the well being and reproduction of fish and wildlife that use Walker Lake. Wildlife that use Weber Reservoir may also be at risk because it is the first reservoir downstream from mining activities in the Bodie and Aurora areas and mercury concentrations in sediment were elevated. Additional data on mercury concentrations in top level predators, such as piscivorous fish and birds, are needed to assess public health and other environmental risks.

  9. Spatial and temporal characteristics of the mesoscale circulation of the California Current from eddy-resolving moored and shipboard measurements

    Microsoft Academic Search

    T. K. Chereskin; M. Y. Morris; P. P. Niiler; P. M. Kosro; R. L. Smith; S. R. Ramp; C. A. Collins; D. L. Musgrave

    2000-01-01

    Moored observations of currents and temperatures made in the upper 600 m on eddy-resolving scales over a 2-year period are used to examine the spatial and temporal characteristics of the California Current mesoscale circulation. The observations were made at three principal longitudes: 124°W, 126°W, and 128°W in the vicinity of Point Arena. They bracket the 600-km-wide band of high mesoscale

  10. Current Status of Western Yellow-Billed Cuckoo along the Sacramento and Feather Rivers, California.

    PubMed

    Dettling, Mark D; Seavy, Nathaniel E; Howell, Christine A; Gardali, Thomas

    2015-01-01

    To evaluate the current status of the western population of the Yellow-billed Cuckoo (Coccyzus americanus) along the Sacramento and Feather rivers in California's Sacramento Valley, we conducted extensive call playback surveys in 2012 and 2013. We also quantified the amount and distribution of potential habitat. Our survey transects were randomly located and spatially balanced to sample representative areas of the potential habitat. We estimated that the total area of potential habitat was 8,134 ha along the Sacramento River and 2,052 ha along the Feather River, for a total of 10,186 ha. Large-scale restoration efforts have created potential habitat along both of these rivers. Despite this increase in the amount of habitat, the number of cuckoos we detected was extremely low. There were 8 detection occasions in 2012 and 10 occasions in 2013 on the Sacramento River, in both restored and remnant habitat. We had no detections on the Feather River in either year. We compared our results to 10 historic studies from as far back as 1972 and found that the Yellow-billed Cuckoo had unprecedentedly low numbers in 2010, 2012, and 2013. The current limiting factor for the Yellow-billed Cuckoo in the Sacramento Valley is likely not the amount of appropriate vegetation, as restoration has created more habitat over the last 30 years. Reasons for the cuckoo decline on the Sacramento and Feather rivers are unclear. PMID:25915801

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

    Microsoft Academic Search

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

    2008-01-01

    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

  12. Current-topography interactions at mid-ocean seamounts and the impact on pelagic ecosystems

    Microsoft Academic Search

    George W. Boehlert

    1988-01-01

    Ocean currents impinging on topographic obstacles such as seamounts create a high level of variability in mesoscale physical\\u000a oceanography. In the N Pacific, for example, the structure of the Kuroshio and its extension differ significantly E and W\\u000a of the Emperor Seamount chain, and eddy fields detected downstream may be attributed to seamount effects. Nearfield effects\\u000a of seamounts have been

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

    Microsoft Academic Search

    Víctor H. Luja; Ricardo Rodríguez-Estrella

    2010-01-01

    The American bullfrog (Lithobates catesbeianus), considered as one of the world’s 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 35 years

  14. Tides, and tidal and residual currents in Suisun and San Pablo bays, California; results of measurements, 1986

    USGS Publications Warehouse

    Gartner, J.W.; Yost, B.T.

    1988-01-01

    Current meter data collected at 11 stations and water level data collected at one station in Suisun and San Pablo Bays, California, in 1986 are compiled in this report. Current-meter measurements include current speed and direction, and water temperature and salinity (computed from temperature and conductivity). For each of the 19 current-meter records, data are presented in two forms. These are: (1) results of harmonic analysis; and (2) plots of tidal current speed and direction versus time and plots of temperature and salinity versus time. Spatial distribution of the properties of tidal currents are given in graphic form. In addition, Eulerian residual currents have been compiled by using a vector-averaging technique. Water level data are presented in the form of a time-series plot and the results of harmonic analysis. (USGS)

  15. Conserving the evolutionary potential of California valley oak (Quercus lobata Née): a multivariate genetic approach to conservation planning

    Microsoft Academic Search

    DELPHINE GRIVET; VICTORIA L. SORK; ROBERT D. WESTFALL; F R A N K W. D AV

    2007-01-01

    California valley oak (Quercus lobata Née) is a seriously threatened endemic oak species in California and a keystone species for foothill oak ecosystems. Urban and agricultural development affects a significant fraction of the species' range and predicted climate change is likely to dislocate many current populations. Here, we explore spatial patterns of multivariate genotypes and genetic diversity throughout the range

  16. California coast nearshore processes study. [nearshore currents, sediment transport, estuaries, and river discharge

    NASA Technical Reports Server (NTRS)

    Pirie, D. M.; Steller, D. D. (principal investigators)

    1973-01-01

    The author has identified the following significant results. Large scale sediment plumes from intermittent streams and rivers form detectable seasonal patterns on ERTS-1 imagery. The ocean current systems, as plotted from three California coast ERTS mosaics, were identified. Offshore patterns of sediment in areas such as the Santa Barbara Channel are traceable. These patterns extend offshore to heretofore unanticipated ranges as shown on the ERTS-1 imagery. Flying spot scanner enhancements of NASA tapes resulted in details of subtle and often invisible (to the eye) nearshore features. The suspended sediments off San Francisco and in Monterey Bay are emphasized in detail. These are areas of extremely changeable offshore sediment transport patterns. Computer generated contouring of radiance levels resulted in maps that can be used in determining surface and nearsurface suspended sediment distribution. Tentative calibrations of ERTS-1 spectral brightness against sediment load have been made using shipboard measurements. Information from the combined enhancement and interpretation techniques is applicable to operational coastal engineering programs.

  17. Temporal and sex-specific variability in Rhinoceros Auklet diet in the central California Current system

    NASA Astrophysics Data System (ADS)

    Carle, Ryan D.; Beck, Jessie N.; Calleri, David M.; Hester, Michelle M.

    2015-06-01

    We used stable isotopes (?15N and ?13C) and compared prey provided to chicks by each sex to evaluate seasonal and sex-specific diets in Rhinoceros Auklets (Cerorhinca monocerata) in the central California Current system during 2012-2013. Mixing models indicated northern anchovy (Engraulis mordax) were important prey for adults during fall/winter and juvenile rockfishes (Sebastes spp.) were important prey during incubation both years. Adult trophic level increased between incubation and chick-rearing periods in both years. During 2012, ?15N and ?13C of chick-rearing males and females differed significantly; mixing models indicated that females ate more Pacific saury (Cololabis saira) and less market squid (Doryteuthis opalescens) than males. Likewise, females delivered significantly more Pacific saury and less market squid to chicks than males during 2012. Chick growth (g d- 1) and chick survival to fledging were significantly lower during 2012 than 2013, likely because chicks were fed lesser quality prey or fed less frequently in 2012. Lesser body mass of females during incubation in 2012 indicated sex-specific diet differences may have been related to female energetic constraints. The observed variability in Rhinoceros Auklet diet underscores the importance of managing multiple prey populations in this system so that generalist predators have sufficient resources through changing conditions.

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

    Microsoft Academic Search

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

    2008-01-01

    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\\

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

    NASA Astrophysics Data System (ADS)

    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

    Sedimentary records from California's Northern Channel Islands and the adjacent Santa Barbara Basin (SBB) indicate intense regional biomass burning (wildfire) at the Ållerød-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 Ållerød-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.].

  20. Metagenomic analysis of microbial consortium from natural crude oil that seeps into the marine ecosystem offshore Southern California

    PubMed Central

    Hawley, Erik R.; Piao, Hailan; Scott, Nicole M.; Malfatti, Stephanie; Pagani, Ioanna; Huntemann, Marcel; Chen, Amy; Glavina del Rio, Tijana; Foster, Brian; Copeland, Alex; Jansson, Janet; Pati, Amrita; Tringe, Susannah; Gilbert, Jack A.; Lorenson, Thomas D.; Hess, Matthias

    2014-01-01

    Crude oils can be major contaminants of the marine ecosystem and microorganisms play a significant role in the degradation of its main constituents. To increase our understanding of the microbial hydrocarbon degradation process in the marine ecosystem, we collected crude oil from an active seep area located in the Santa Barbara Channel (SBC) and generated a total of about 52 Gb of raw metagenomic sequence data. The assembled data comprised ~500 Mb, representing ~1.1 million genes derived primarily from chemolithoautotrophic bacteria. Members of Oceanospirillales, a bacterial order belonging to the Deltaproteobacteria, recruited less than 2% of the assembled genes within the SBC metagenome. In contrast, the microbial community associated with the oil plume that developed in the aftermath of the Deepwater Horizon (DWH) blowout in 2010, was dominated by Oceanospirillales, which comprised more than 60% of the metagenomic data generated from the DWH oil plume. This suggests that Oceanospirillales might play a less significant role in the microbially mediated hydrocarbon conversion within the SBC seep oil compared to the DWH plume oil. We hypothesize that this difference results from the SBC oil seep being mostly anaerobic, while the DWH oil plume is aerobic. Within the Archaea, the phylum Euryarchaeota, recruited more than 95% of the assembled archaeal sequences from the SBC oil seep metagenome, with more than 50% of the sequences assigned to members of the orders Methanomicrobiales and Methanosarcinales. These orders contain organisms capable of anaerobic methanogenesis and methane oxidation (AOM) and we hypothesize that these orders – and their metabolic capabilities – may be fundamental to the ecology of the SBC oil seep. PMID:25197496

  1. Climate change, reproductive performance and diet composition of marine birds in the southern California Current system, 1969 1997

    NASA Astrophysics Data System (ADS)

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

    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, 1969-1997. 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 penicillatus) in central California was the only species to demonstrate a secular increase in performance through time, a pattern that remains unexplained. Ashy Storm-petrel ( Oceanodroma homochroa) and Pelagic Cormorant ( Phalacrocorax pelagicus) demonstrated curvilinear patterns of change, with decreasing reproductive performance in the past decade. All other species including Western Gull ( Larus occidentalis), Pigeon Guillemot ( Cepphus columba), Xantus's Murrelet ( Synthiloboramphus hypoleucus), Common Murre ( Uria aalge), Cassin's Auklet ( Ptychoramphus aleuticus) and Rhinoceros Auklet ( Cerorhinca monocerata) showed diminishing reproductive performance through time. Patterns of change for the murre and auklets were not significant, presumably because of a lack of reproductive variation for these species, which display a conservative breeding effort (i.e. single-egg clutches). Changes in the birds' abilities to provision young and maintain chick survival during May-July each year appeared most closely related to overall changes in reproductive performance. Dietary change indicated a decline in use of juvenile rockfish ( Sebastes spp.) by marine birds in central California. There was also significant interannual variability in consumption of juvenile rockfish and the euphausiid Thysanoessa spinifera. Patterns of change in marine bird reproductive performance were generally concordant between southern and central California after considering the period of recovery for Brown Pelican and Double-crested Cormorant. The decline in reproductive performance and changes in diet composition do not appear directly related to the polarity reversal of the Pacific Decadal Oscillation in 1976/1977. Instead, reproductive performance and dietary characteristics indicate substantial change in the late 1980s, suggesting another regime-shift at that time.

  2. Current Status and Future Prospects for the Assessment of Marine and Coastal Ecosystem Services: A Systematic Review

    PubMed Central

    Liquete, Camino; Piroddi, Chiara; Drakou, Evangelia G.; Gurney, Leigh; Katsanevakis, Stelios; Charef, Aymen; Egoh, Benis

    2013-01-01

    Background Research on ecosystem services has grown exponentially during the last decade. Most of the studies have focused on assessing and mapping terrestrial ecosystem services highlighting a knowledge gap on marine and coastal ecosystem services (MCES) and an urgent need to assess them. Methodology/Principal Findings We reviewed and summarized existing scientific literature related to MCES with the aim of extracting and classifying indicators used to assess and map them. We found 145 papers that specifically assessed marine and coastal ecosystem services from which we extracted 476 indicators. Food provision, in particular fisheries, was the most extensively analyzed MCES while water purification and coastal protection were the most frequently studied regulating and maintenance services. Also recreation and tourism under the cultural services was relatively well assessed. We highlight knowledge gaps regarding the availability of indicators that measure the capacity, flow or benefit derived from each ecosystem service. The majority of the case studies was found in mangroves and coastal wetlands and was mainly concentrated in Europe and North America. Our systematic review highlighted the need of an improved ecosystem service classification for marine and coastal systems, which is herein proposed with definitions and links to previous classifications. Conclusions/Significance This review summarizes the state of available information related to ecosystem services associated with marine and coastal ecosystems. The cataloging of MCES indicators and the integrated classification of MCES provided in this paper establish a background that can facilitate the planning and integration of future assessments. The final goal is to establish a consistent structure and populate it with information able to support the implementation of biodiversity conservation policies. PMID:23844080

  3. Measurements of slope currents and internal tides on the Continental Shelf and slope off Newport Beach, California

    USGS Publications Warehouse

    Rosenberger, Kurt J.; Noble, Marlene A.; Norris, Benjamin K.

    2014-01-01

    An array of seven moorings housing current meters and oceanographic sensors was deployed for 6 months at 5 sites on the Continental Shelf and slope off Newport Beach, California, from July 2011 to January 2012. Full water-column profiles of currents were acquired at all five sites, and a profile of water-column temperature was also acquired at two of the five sites for the duration of the deployment. In conjunction with this deployment, the Orange County Sanitation District deployed four bottom platforms with current meters on the San Pedro Shelf, and these meters provided water-column profiles of currents. The data from this program will provide the basis for an investigation of the interaction between the deep water flow over the slope and the internal tide on the Continental Shelf.

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

    NASA Astrophysics Data System (ADS)

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

    2010-12-01

    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 Mediterranean climate. Using simulations, we established that our sampling interval must be less than monthly to keep the turnover rate error to less than 10%. Adhering to this interval, we measured fine root turnover rate by mark-recapture modeling methods and compared predicted with observed turnover rates. The best selected model indicated that these rates were a function of diameter, length, soil temperature, and soil water content. Turnover rate increased with decreasing diameter and length and increasing soil temperature and soil water content. We found a yearly pattern of hysteresis between fine root production, mortality, and turnover rate relative to soil temperature. This was explained by soil temperature-moisture hysteresis using our best selected model. Production and turnover rate were greater in spring to early summer when both soil temperature and soil moisture were high, resulting in a seasonal variation of belowground net primary production. We suggest that this behavior could be a result of fine roots' strategy to cope with a limited growing season of a semiarid Mediterranean climate.

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

    PubMed

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

    2006-06-01

    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

  6. Is the current increase in fire recurrence causing a shift in the soil fertility of Iberian ecosystems?

    NASA Astrophysics Data System (ADS)

    Mayor, Ángeles G.; Keizer, Jan Jacob; González-Pelayo, Óscar; Valdecantos, Alejandro; Vallejo, Ramón; de Ruiter, Peter

    2015-04-01

    Since the mid of the last century fire recurrence has increased in the Iberian peninsula and the overall Mediterranean basin due to changes in land use and climate. The warmer and drier climate projected for this region will further increase the risk of wildfire occurrence and of increasing fire recurrence. Although the impact of wildfires on soil nutrient content in this region has been extensively studied, still few works have assessed this impact on the basis of fire recurrence. This study assesses the changes in soil nutrient status of two Iberian ecosystems, Várzea (N Portugal) and Valencia (E Spain), affected by different levels of fire recurrence and where short inter-fire periods have promoted a transition from pine woodlands to shrublands. Trends towards soil fertility loss with increasing fire recurrence (one, two, three or four fires in 37 years) were observed in the two study sites. The sites differed when soil fertility of areas burned several times were compared with long unburned references. In Valencia, overall soil fertility of the surface mineral soil was lower in areas burned two or three times than in long unburned areas, twenty and eight years after the last fire, respectively. On the contrary, total organic matter in Várzea was higher in burned than in unburned soils one year after the occurrence of one or four fires. However, a negative impact of fire was observed for integrated indicators of soil quality, such as hot-water carbon and potentially mineralizable nitrogen, suggesting that fire also had an adverse effect on substrate quality in Várzea. Our results suggest that the current trend of increasing fire recurrence in Southern Europe may result in losses or alterations of soil organic matter, particularly when fire promotes a transition from pine woodland to shrubland.

  7. Comparison of the seasonal and interannual variability of phytoplankton pigment concentrations in the Peru and California Current systems

    NASA Technical Reports Server (NTRS)

    Thomas, A. C.; Huang, F.; Strub, P. T.; James, C.

    1994-01-01

    Monthly composite images from the global coastal zone color scanner (CZCS) data set are used to provide an initial illustration and comparison of seasonal and interannual variability of phytoplankton pigment concentration along the western coasts of South and North America in the Peru Current system (PCS) and California Current system (CCS). The analysis utilizes the entire time series of available data (November 1978 to June 1986) to form a mean annual cycle and an index of interannual variability for a series of both latitudinal and cross-shelf regions within each current system. Within 100 km of the coast, the strongest seasonal cycles in the CCS are in two regions, one between 34 deg and 45 deg N and the second between 24 deg and 29 deg N, each with maximum concentrations (greater than 3.0 mg m(exp-3)) in May-June. Weaker seasonal variability is present north of 45 deg N and in the Southern California Bight region (32 deg N). Within the PCS, in the same 100-km-wide coastal region, highest (greater than 45 deg S) and lowest (less than 20 deg S) latitude regions have a similar seasonal cycle with maximum concentrations (greater than 1.5 mg m(exp -3)) during the austral spring, summer, and fall, matching that evident throughout the CCS. Between these regions, off northern and central Chile, the seasonal maximum occurs during July-August (austral winter), contrary to the influence of upwelling favorable winds. Within the CCS, the dominant feature of interannual variability in the 8-year time series is a strong negative concentration anomaly in 1983, an El Nino year. The relative value of this negative anomaly is strongest off central California and is followed by an even stronger negative anomaly is strongest off central California and is followed by an even stronger negative anomaly in 1984 off Baja, California. In the PCS, strong negative anomalies during the 1982-1983 El Nino period are evident only off the Peruvian coast and are evident there only in the regions 100 km or more from the coast. Although negative anomalies associated with the El Nino were not present at higher latitudes (more than approximately 20 deg S) in the PCS, the extremely sparse sampling weakens our confidence in the results of the interannual analysis in this region. An upper estimate of the systematic winter bias remaining in the global CZCS data after reprocessing with the multiple scattering algorithm is given in the appendix.

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

    Microsoft Academic Search

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

    2010-01-01

    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

  9. Influence of Nutrient Loading on the Invasion of an Alien Plant Species, Giant Reed (Arundo donax), in Southern California Riparian Ecosystems

    E-print Network

    Ambrose, Richard F.; Rundel, Philip W.

    2007-01-01

    and Restoration Implications ..24 CHAPTER 3 - WILDFIRE PROMOTES GIANT REED (ARUNDO DONAX) INVASION IN RIPARIAN ECOSYSTEMS .and Restoration Implications This study elucidated the influence of anthropogenic nutrient inputs on invasion of riparian ecosystems

  10. Ekstrom, Draft 11/14/08 California Current Large Marine Ecosystem: Publicly Available Dataset of State and

    E-print Network

    Stanford University

    : Engineering Informatics Group Structural Engineering and Geomechanics Civil & Environmental Engineering Jerry Yang & Akiko Yamazaki Environment & Energy Building 473 Via Ortega, #228 Stanford, CA 94305-4020 805

  11. Progress report on a 3D coupled physical-biological pelagic ecosystem model of the East Australian Current

    E-print Network

    Baird, Mark

    , Australia 13th December 2003 1 Introduction An ARC Discovery Project (DP0209193) has funded the development effect of cross-shelf topography on a pelagic ecosystem response to upwelling favourable winds favourable) wind and a southerly (downwelling favourable) wind. 1 #12;The animations of these simulations can

  12. Is it restoration or reconciliation? California's experience restoring the Sacramento - San Joaquin River Delta provides lessons learned and pathways forward to sustain critical ecosystem functions and services in a highly managed riverine delta.

    NASA Astrophysics Data System (ADS)

    Viers, J. H.; Kelsey, R.

    2014-12-01

    Reconciling the needs of nature and people in California's Sacramento - San Joaquin River Delta represents one of the most critical ecosystem management imperatives in western North America. Over 150 years the Delta has been managed for near-term human benefits and in the process 95% of riverine and deltaic wetlands have been lost throughout the region. Despite extensive land conversion and alteration of hydrological and physical processes, the Delta remains important habitat for migratory birds and is home to over 60% of California's native fish species. It is also the waterwheel for the state's vast water distribution network and is maintained by a system of constructed levees that are at risk from catastrophic failure due to sea level rise, floods, and/or seismic activity. Such a collapse would have dire consequences for > 25M humans and world's 10th largest economy that depend on its freshwater. Thus, the ultimate cost of this ecosystem alteration and simplification is a riverscape that is no longer reliable for nature or people. For 30 years, attempts to 'restore' Delta ecosystems and improve reliability have met with mixed results. For example, reconnection of floodplains to floodwaters has resulted in improved ecological health for native fishes and recharge to localized aquifers. Uncoordinated releases of discharges below dams, however, have resulted in diminished water quality and populations of indicator species. Attempts to create wildlife friendly farms have been countered by an increase in perennial agriculture and commensurate increases in irrigation water demand. From these lessons learned, we demonstrate three key components of a reconciled Delta that will be necessary in the future: 1) full restoration of critical habitats, reconnecting land and water to rebuild ecosystem function; 2) landscape redesign, incorporating natural and engineered infrastructure to create a biologically diverse, resilient landscape to support both agriculture and natural ecosystems, while reducing the impacts of climate change; and 3) recognition that some ecosystem components, including less resilient species, may be lost and other novel components may emerge. These findings serve to reconcile conflicting demands and restoring ecosystem functions in highly altered wetland landscapes worldwide.

  13. University of California: California Agriculture

    NSDL National Science Digital Library

    Based on our nation's heavy reliance on food grown in California, this University of California publication regarding the agricultural affairs of the 31st state will be appreciated by researchers and agriculturalists from around the country. First published in 1946, "_California Agriculture_ is a peer-reviewed journal reporting research, reviews and news from the Division of Agriculture and Natural Resources of the University of California." Site visitors may view abstracts or full text documents of research articles from current and previous issues. In addition, free domestic subscriptions may be ordered online (the journal currently serves around 14,000 domestic subscribers). The site also provides downloadable guidelines for writers.

  14. Variability of pigment biomass in the California Current system as determined by satellite imagery. I - Spatial variability

    NASA Technical Reports Server (NTRS)

    Smith, Raymond C.; Zhang, Xueyun; Michaelsen, Joel

    1988-01-01

    Spatial variability of chlorophyll in the California Current system was analyzed using Coastal Zone Color Scanner (CZCS) imagery. A total of 48 images were analyzed to produce seasonal averages and variances, gradients, and power spectra. Roughly one third to one half of the variance in pigment biomass can be explained by consistent, large-scale gradients. In general, biomass is higher in the north and in nearshore areas. Nearshore areas also have proportionally more small-scale variability than the areas offshore. Slopes of the power spectra for nearshore areas are about -2.2 (for spatial scales of 10-100 km), while slopes for offshore areas are about -3. In addition, the power spectra show evidence of a change in slope at about 10 km, with slopes of about -1 for shorter-length scales. This may indicate that biological processes dominate the smaller scales, while mesoscale eddies and geostrophic currents dominate the larger scales.

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

    USGS Publications Warehouse

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

    2000-01-01

    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.

  16. CARBON DIOXIDE SEQUESTRATION IN TERRESTRIAL ECOSYSTEMS

    EPA Science Inventory

    The terrestrial biosphere plays a prominent role in the global carbon (C) cycle. errestrial ecosystems are currently accumulating C and it appears feasible to manage existing terrestrial (forest, agronomic, desert) ecosystems to maintain or increase C storage. orest ecosystems ca...

  17. Climate warming and the decline of zooplankton in the California current

    SciTech Connect

    Roemmich, D.; McGowan, J. [Univ. of California, San Diego, CA (United States)

    1995-03-03

    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{degrees}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 new biological production and hence supported a smaller zooplankton population. Continued warming could lead to further decline of zooplankton. 10 refs., 5 figs.

  18. Ecosystem Explorations

    NSDL National Science Digital Library

    Kristen L. Gunckel

    1999-09-01

    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

  19. Variability of pigment biomass in the California Current system as determined by satellite imagery. II - Temporal variability

    NASA Technical Reports Server (NTRS)

    Michaelsen, Joel; Zhang, Xueyun; Smith, Raymond C.

    1988-01-01

    Characteristics of temporal variability in the California Current system are analyzed using a 30-month time series of CZCS imagery. About 20-25 percent of the variance is produced by a periodic annual cycle with peak values in winter. Analysis of ship-based chlorophyll measurements indicates that the winter peak is only characteristic of the upper portion of the euphotic zone and that total water column chlorophyll peaks during the spring upwelling season. Satellite studies of intraannual variability are modulated by strong 5- to 6-day oscillation in the availability of usable imagery, resulting from a combination of satellite orbital dynamics, which produces images of the study area roughly 4 out of every 6 days, and an oscillation in cloud cover, which controls the availability of clear imagery. The cloud cover oscillation, which is also present in coastal winds, undoubtedly affects the ocean surface and biases the data obtained by satellites. Analysis of data using a 5-day time step indicates that the predominant mode of nonseasonal variability is characterized by in-phase fluctuations throughout the southern and central California coastal region.

  20. Changes in forage fish community indicated by the diet of the Brandt's cormorant (Phalacrocorax penicillatus) in the central California Current

    NASA Astrophysics Data System (ADS)

    Elliott, Meredith L.; Bradley, Russell W.; Robinette, Dan P.; Jahncke, Jaime

    2015-06-01

    The population, productivity and diet of two Brandt's cormorant (Phalacrocorax penicillatus) colonies located in the central California Current were compared. The offshore colony on Southeast Farallon Island has experienced a declining population over time and anomalously low productivity in recent years. The nearshore colony near Point Arguello has been increasing and its productivity has remained stable. The diets of cormorants at the two colonies elucidated by analysis of regurgitated pellets, while different, have shown similar decreases in the consumption of northern anchovy (Engraulis mordax) since 2008, followed by increased consumption of rockfish (Sebastes spp.) and flatfish (order Pleuronectiformes). By using the diet results from another seabird nesting in central California, the rhinoceros auklet (Cerorhinca monocerata), and one from which whole fish can be obtained, we found that the rockfish species assemblage has changed with offshore rockfish species decreasing while nearshore ones have increased. This change in the rockfish species has negatively impacted Brandt's cormorants at the offshore colony by forcing them to make longer foraging trips to meet energy needs of themselves and their chicks; this has led to low breeding success and a declining population at this site. On the other hand, the nearshore colony has abundant nearby food resources, and it has prospered. These results underscore the value of using seabird data from multiple colonies to better understand changes occurring in the marine environment.

  1. Seasonal to Decadal-Scale Variability in Satellite Ocean Color and Sea Surface Temperature for the California Current System

    NASA Technical Reports Server (NTRS)

    Mitchell, B. Greg; Kahru, Mati; Marra, John (Technical Monitor)

    2002-01-01

    Support for this project was used to develop satellite ocean color and temperature indices (SOCTI) for the California Current System (CCS) using the historic record of CZCS West Coast Time Series (WCTS), OCTS, WiFS and AVHRR SST. The ocean color satellite data have been evaluated in relation to CalCOFI data sets for chlorophyll (CZCS) and ocean spectral reflectance and chlorophyll OCTS and SeaWiFS. New algorithms for the three missions have been implemented based on in-water algorithm data sets, or in the case of CZCS, by comparing retrieved pigments with ship-based observations. New algorithms for absorption coefficients, diffuse attenuation coefficients and primary production have also been evaluated. Satellite retrievals are being evaluated based on our large data set of pigments and optics from CalCOFI.

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

    NASA Astrophysics Data System (ADS)

    Gutiérrez, Manuel O.; López, Manuel; Candela, Julio; Castro, Rubén.; Mascarenhas, Affonso; Collins, Curtis A.

    2014-08-01

    Subsurface 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.

  3. Predicting long-term carbon sequestration in response to CO2 enrichment: How and why do current ecosystem models differ?

    NASA Astrophysics Data System (ADS)

    Walker, Anthony P.; Zaehle, Sönke; Medlyn, Belinda E.; De Kauwe, Martin G.; Asao, Shinichi; Hickler, Thomas; Parton, William; Ricciuto, Daniel M.; Wang, Ying-Ping; Wârlind, David; Norby, Richard J.

    2015-04-01

    Large uncertainty exists in model projections of the land carbon (C) sink response to increasing atmospheric CO2. Free-Air CO2 Enrichment (FACE) experiments lasting a decade or more have investigated ecosystem responses to a step change in atmospheric CO2 concentration. To interpret FACE results in the context of gradual increases in atmospheric CO2 over decades to centuries, we used a suite of seven models to simulate the Duke and Oak Ridge FACE experiments extended for 300 years of CO2 enrichment. We also determine key modeling assumptions that drive divergent projections of terrestrial C uptake and evaluate whether these assumptions can be constrained by experimental evidence. All models simulated increased terrestrial C pools resulting from CO2 enrichment, though there was substantial variability in quasi-equilibrium C sequestration and rates of change. In two of two models that assume that plant nitrogen (N) uptake is solely a function of soil N supply, the net primary production response to elevated CO2 became progressively N limited. In four of five models that assume that N uptake is a function of both soil N supply and plant N demand, elevated CO2 led to reduced ecosystem N losses and thus progressively relaxed nitrogen limitation. Many allocation assumptions resulted in increased wood allocation relative to leaves and roots which reduced the vegetation turnover rate and increased C sequestration. In addition, self-thinning assumptions had a substantial impact on C sequestration in two models. Accurate representation of N process dynamics (in particular N uptake), allocation, and forest self-thinning is key to minimizing uncertainty in projections of future C sequestration in response to elevated atmospheric CO2.

  4. Ocean warming and seabird communities of the southern California Current System (1987-98): response at multiple temporal scales

    NASA Astrophysics Data System (ADS)

    Hyrenbach, K. David; Veit, Richard R.

    2003-08-01

    Declines in ocean productivity and shifts in species assemblages along the West Coast of North America during the second half of the XXth century have been attributed to the concurrent warming of the California Current. This paper addresses changes in the avifauna off southern California between May 1987 and September 1998, in response to shifting water mass distributions over short (<1 year) and long (interannual) temporal scales. More specifically, our research focuses on the relative importance of distinct foraging guilds and species assemblages with an affinity for warm and cold water. Over the long term, the avifauna off southern California shifted from a 'high-productivity' community typical of eastern boundary upwelling systems, to a 'low-productivity' assemblage similar to those inhabiting the subtropical gyres. Overall seabird abundance decreased; the relative importance of cold-water seabirds that dive in pursuit of prey declined; and warm-water species that feed at the surface and plunge to capture prey became more numerous. These community-level changes are consistent with the northward shifts in species ranges and the declining ocean productivity anticipated as a result of global warming. However, the response of individual taxa with an affinity for warm-water and cold-water conditions has been more difficult to predict, due to differences in species-specific responses to ocean warming. The three cold-water species investigated (Sooty Shearwater Puffinus griseus, Cassin's Auklet Ptychoramphus aleuticus, and Rhinoceros Auklet Cerorhinca monocerata) decreased in abundance during this study. On the other hand, only one of the six warm-water species considered (Pink-footed Shearwater, Puffinus creatopus) increased significantly over the long term. Yet, the warm-water Leach's Storm-petrel ( Oceanodroma leucorhoa) increased between 1987 and 1993, and then declined between 1994 and 1998. Moreover, cross-correlations between seasonally adjusted anomalies of bird abundance and ocean temperature revealed that seabirds responded differently to ocean warming over intermediate (1-8 years), and long (8-12 years) time scales. We hypothesize that this nonlinear behavior of seabird populations in response to ocean warming is caused by the juxtaposition of distinct behavioral and demographic responses operating at different temporal scales.

  5. Linkages Between Upwelling and Shell Characteristics of Mytilus californianus: Morphology and Stable Isotope (?13C, ?18O) Signatures of a Carbonate Archive from the California Current

    NASA Astrophysics Data System (ADS)

    Hosfelt, J. D.; Hill, T. M.; Russell, A. D.; Bean, J. R.; Sanford, E.; Gaylord, B.

    2014-12-01

    Many calcareous organisms are known to record the ambient environmental conditions in which they grow, and their calcium carbonate skeletons are often valuable archives of climate records. Mytilus californianus, a widely distributed species of intertidal mussel, experiences a spatial mosaic of oceanographic conditions as it grows within the California Current System. Periodic episodes of upwelling bring high-CO2 waters to the surface, during which California coastal waters are similar to projected conditions and act as a natural analogue to future ocean acidification. To examine the link between upwelling and shell characteristics of M. californianus, we analyzed the morphology and stable isotope (?13C, ?18O) signatures of mussel specimens collected live from seven study sites within the California Current System. Morphometric analyses utilized a combination of elliptic Fourier analysis and shell thickness measurements to determine the influence of low pH waters on the growth morphology and ecological fitness of M. californianus. These geochemical and morphological analyses were compared with concurrent high-resolution environmental (T, S, pH, TA, DIC) records from these seven study sites from 2010-2013. With appropriate calibration, new archives from modern M. californianus shells could provide a valuable tool to enable environmental reconstructions within the California Current System. These archives could in turn be used to predict the future consequences of continuing ocean acidification, as well as reconstruct past (archeological) conditions.

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

    Microsoft Academic Search

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

    2011-01-01

    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

  7. Measuring Possible Tsunami Currents from the April 1, 2014 Mw 8.2 Chile Earthquake in Crescent City, California

    NASA Astrophysics Data System (ADS)

    Admire, A. R.; Crawford, G. B.; Dengler, L. A.

    2014-12-01

    Crescent City, California has a long history of damaging tsunamis. Thirty-nine tsunamis have been recorded since 1933, including five that caused damage. Crescent City's harbor and small boat basin are particularly vulnerable to strong currents. Humboldt State University has installed Acoustic Doppler Profilers (ADPs) in order to directly measure water pressure fluctuations and currents caused by tsunamis. An instrument in Humboldt Bay, ~100 km south of Crescent City, recorded tsunamis generated by the 2010 Mw 8.7 Chile and 2011 Mw 9.0 Japan earthquakes and demonstrated the usefulness of ADPs in measuring tsunami currents. In 2013, an ADP was deployed in Crescent City's harbor adjacent to the NOAA tide gauge. On April 1, 2014, a Mw 8.2 earthquake occurred in northern Chile, producing a modest Pacific-wide tsunami and a 16 cm peak amplitude on the Crescent City tide gauge. We analyze the ADP data before and during the expected arrival of the April 2 tsunami to see if a tsunami signal is present. Tidal currents are generally small (5 cm/s or less). For two months before the tsunami, intermittent, high-frequency variability is present in velocity and pressure at periods on the order of 20, 9 and 5 min, which compare favorably to modal periods predicted using some simplified models of open-ended basins. For several hours after the tsunami arrival on April 2, spectral power levels in velocity and pressure around the 20 min period are notably enhanced. These results suggest that: (1) the observed periods of enhanced variability represent the first three modes (n=0, 1 and 2) of free oscillations in the harbor, (2) the dominant period of (non-tidal) oscillations observed during the April 2, 2014 tsunami (~20 min) and during previous tsunamis (e.g., the water level record for the March 11, 2011 tsunami; also ~20 min) represents harbor resonance corresponding to the lowest order mode, and (3) this event is very near the ADP limit of detectability with peak tsunami currents of 5-10 cm/s and higher frequency variability and instrument noise root-mean-squared amplitude of 4-5 cm/s.

  8. The Occupational Mobility of Current and Former Farm Workers: A Comparative Analysis in Two California Labor Markets. California Agricultural Studies, 91-3.

    ERIC Educational Resources Information Center

    Gabbard, Susan; Goldring, Luin

    This report examines the occupational mobility of agricultural workers in two California labor markets and the effects of the Immigration Reform and Control Act and individual, job, and labor-market characteristics on such mobility. Interviews were conducted among a randomly selected sample of 162 households, which included 401 workers in southern…

  9. Long-term trends and variability in the larvae of Pacific sardine and associated fish species of the California Current region

    NASA Astrophysics Data System (ADS)

    Smith, Paul E.; Moser, H. Geoffrey

    2003-08-01

    Fifty-year ichthyoplankton and oceanographic time series of the California Cooperative Oceanic Fisheries Investigations were used to describe changes in larval fish abundance and associated habitat features in the Southern California Bight region, extending seaward to the limits of the California Current. The ichthyoplankton data set for this analysis was based on single tows taken at all CalCOFI survey stations occupied within the current sampling pattern from 1951 to 2000 and consisted of a total of 11,917 samples from which 1,365,988 fish larvae were identified. The analysis included data on habitat temperature, macrozooplankton volumes, and 14 taxa of larval fishes, some of commercial interest (Pacific sardine, Pacific hake, Pacific and jack mackerel, and rockfishes), and a group of important mesopelagic species that represent specific habitats in the California Current region. Data are presented in a series of graphs showing changes in average abundance, triennial abundance ratios, and normalized quarterly abundance (1988-2000 only). Larval data clearly track the decline and recovery of the Pacific sardine population. Mesopelagic larvae of southern offshore species had the greatest response to the regime shift of 1976-77, increasing markedly in the Southern California Bight region after 1977. Likewise, this group of species showed the greatest response to the 1957-59 El Niño. There was no consistent response in larval abundance of Subarctic-Transitional mesopelagic species and nearshore taxa to the 1976-77 regime shift. Most of the species showed a negative shift in triennial larval abundance ratios in relation to hypothesized 1989-90 and 1998-99 regime shifts. These changes are discussed in relation to changes in temperature and macrozooplankton volumes.

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

    USGS Publications Warehouse

    Gartner, J.W.

    2004-01-01

    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.

  11. Connectivity in the northern Gulf of California from particle tracking in a three-dimensional numerical model

    Microsoft Academic Search

    S. G. Marinone; M. J. Ulloa; A. Parés-Sierra; M. F. Lavín; R. Cudney-Bueno

    2008-01-01

    The northern Gulf of California, Mexico, is one of the most productive and diverse marine ecosystems in the world. It currently harbors three marine protected areas, including two biosphere reserves. Despite its significance as a conservation site and its importance for Mexico's fisheries, proper knowledge of population connectivity and larvae dispersal from spawning sites is largely lacking. Our study focuses

  12. A review of current practices and the future for deep well injection in the upper Miocene Stevens sand, Kern County, California

    Microsoft Academic Search

    S. C. Kiser; D. W. Chenot

    1991-01-01

    Waste-water disposal is a major concern of the petroleum business, especially because of complications associated with many produced-water surface-impoundment percolation facilities. In the San Joaquin Valley, California, the current environmental regulations protecting the potentially usable groundwaters are stringent. the Stevens has significant potential as a disposal zone that may offer considerable capacity when the project is designed using proper geologic

  13. Long-term change and stability in the California Current System: lessons from CalCOFI and other long-term data sets

    Microsoft Academic Search

    Ginger A Rebstock

    2003-01-01

    The California Current System (CCS) is a highly variable system, both spatially and temporally, that is strongly affected by low-frequency climatic fluctuations. This paper reviews evidence for long-term (decadal-scale) change in the physics and biology of the CCS over the last 50–100 years, as well as evidence for stability in planktonic community structure and long-term persistence of populations. Increases in

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

    PubMed Central

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

    2014-01-01

    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

  15. Links between carbonate productivity and ENSO variability in the southern California Current System for the past 2 Kyrs

    NASA Astrophysics Data System (ADS)

    Abella-Gutiérrez, J. L.; Herguera, J. C.

    2014-12-01

    San Lázaro Basin (SLB) is a suboxic basin characteristic for its very high sedimentation rates (1mm/yr) and is located in the dynamic southern boundary of the California Current System (CCS). This southern boundary of the CCS generally extends further south during spring into early summer and retracts towards the north during fall and winter, and this pattern is further amplified or reduced on different time scales, (e.i. interannual timescales by El Niño and La Niña events, or multidecadal ones by the Pacific Decadal Oscillation (PDO)). These oceanographic conditions are related with important differences in the base of the food chain; when the boundary migrates to northern latitudes, the presence of relatively warmer tropical and subtropical waters further stratify the water column, a period when coccolithophorids dominate the microplankton web structure. On the other side, diatoms flourish when the wind-driven circulation expand the subarctic water masses of the CCS to the south and upwelling cells are generated. We find in our cores XRF Ca counts (1 mm resolution) highly correlate with CaCO3 measurements (R=0.56), this last one showing a general decreasing trend over the past 2 Kyrs. The Ca spectrum analysis shows significant peaks for periods centered at 28, 40, 60, 120 yr. The centennial mode of variability of the Ca record shows correlations with Drought area Index from North America. When the variance of this mode is considered, similarities arises with intensity and number of ENSO events from Equatorial archives. Decadal variations of the record are highly correlated (R>0.8) with instrumental measurements of Kaplan sea surface temperature, and the PDO. We will discuss the implications of these periods in the carbonate record and the links between them and other paleoceanographic records in the Pacific.

  16. Ecosystem Health in Mineralized Terrane-Data from Podiform Chromite (Chinese Camp Mining District, California), Quartz Alunite (Castle Peak and Masonic Mining Districts, Nevada/California), and Mo/Cu Porphyry (Battle Mountain Mining District, Nevada) Deposits

    USGS Publications Warehouse

    Blecker, Steve W.; Stillings, Lisa L.; Amacher, Michael C.; Ippolito, James A.; DeCrappeo, Nicole M.

    2010-01-01

    The myriad definitions of soil/ecosystem quality or health are often driven by ecosystem and management concerns, and they typically focus on the ability of the soil to provide functions relating to biological productivity and/or environmental quality. A variety of attempts have been made to create indices that quantify the complexities of soil quality and provide a means of evaluating the impact of various natural and anthropogenic disturbances. Though not without their limitations, indices can improve our understanding of the controls behind ecosystem processes and allow for the distillation of information to help link scientific and management communities. In terrestrial systems, indices were initially developed and modified for agroecosystems; however, the number of studies implementing such indices in nonagricultural systems is growing. Soil quality indices (SQIs) are typically composed of biological (and sometimes physical and chemical) parameters that attempt to reduce the complexity of a system into a metric of a soil's ability to carry out one or more functions. The indicators utilized in SQIs can be as varied as the studies themselves, reflecting the complexity of the soil and ecosystems in which they function. Regardless, effective soil quality indicators should correlate well with soil or ecosystem processes, integrate those properties and processes, and be relevant to management practices. Commonly applied biological indicators include measures associated with soil microbial activity or function (for example, carbon and nitrogen mineralization, respiration, microbial biomass, enzyme activity. Cost, accessibility, ease of interpretation, and presence of existing data often dictate indicator selection given the number of available measures. We employed a large number of soil biological, chemical, and physical measures, along with measures of vegetation cover, density, and productivity, in order to test the utility and sensitivity of these measures within various mineralized terranes. We were also interested in examining these relations in the context of determining appropriate reference conditions with which to compare reclamation efforts. The purpose of this report is to present the data used to develop indices of soil and ecosystem quality associated with mineralized terranes (areas enriched in metal-bearing minerals), specifically podiform chromite, quartz alunite, and Mo/Cu porphyry systems. Within each of these mineralized terranes, a nearby unmineralized counterpart was chosen for comparison. The data consist of soil biological, chemical, and physical parameters, along with vegetation measurements for each of the sites described below. Synthesis of these data and index development will be the subject of future publications.

  17. Coral Ecosystems

    NSDL National Science Digital Library

    National Science Teachers Association (NSTA)

    2006-06-01

    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.

  18. Ecosystem feedbacks to climate change in California: Development, testing, and analysis using a coupled regional atmosphere and land-surface model (WRF3-CLM3.5)

    SciTech Connect

    Subin, Z.M.; Riley, W.J.; Kueppers, L.M.; Jin, J.; Christianson, D.S.; Torn, M.S.

    2010-11-01

    A regional atmosphere model [Weather Research and Forecasting model version 3 (WRF3)] and a land surface model [Community Land Model, version 3.5 (CLM3.5)] were coupled to study the interactions between the atmosphere and possible future California land-cover changes. The impact was evaluated on California's climate of changes in natural vegetation under climate change and of intentional afforestation. The ability of WRF3 to simulate California's climate was assessed by comparing simulations by WRF3-CLM3.5 and WRF3-Noah to observations from 1982 to 1991. Using WRF3-CLM3.5, the authors performed six 13-yr experiments using historical and future large-scale climate boundary conditions from the Geophysical Fluid Dynamics Laboratory Climate Model version 2.1 (GFDL CM2.1). The land-cover scenarios included historical and future natural vegetation from the Mapped Atmosphere-Plant-Soil System-Century 1 (MC1) dynamic vegetation model, in addition to a future 8-million-ha California afforestation scenario. Natural vegetation changes alone caused summer daily-mean 2-m air temperature changes of -0.7 to +1 C in regions without persistent snow cover, depending on the location and the type of vegetation change. Vegetation temperature changes were much larger than the 2-m air temperature changes because of the finescale spatial heterogeneity of the imposed vegetation change. Up to 30% of the magnitude of the summer daily-mean 2-m air temperature increase and 70% of the magnitude of the 1600 local time (LT) vegetation temperature increase projected under future climate change were attributable to the climate-driven shift in land cover. The authors projected that afforestation could cause local 0.2-1.2 C reductions in summer daily-mean 2-m air temperature and 2.0-3.7 C reductions in 1600 LT vegetation temperature for snow-free regions, primarily because of increased evapotranspiration. Because some of these temperature changes are of comparable magnitude to those projected under climate change this century, projections of climate and vegetation change in this region need to consider these climate-vegetation interactions.

  19. 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...

  20. Anthropogenic CO2 invasion into the northeast Pacific based on concurrent ?13CDIC and nutrient profiles from the California Current

    NASA Astrophysics Data System (ADS)

    Ortiz, J. D.; Mix, A. C.; Wheeler, P. A.; Key, R. M.

    2000-09-01

    The stable isotopic signature of dissolved inorganic carbon (?13CDIC) in the northeast Pacific Ocean is lower in near-surface waters by ?1.1‰ relative to values predicted from global oceanic trends of ?13CDIC versus nutrients. A combination of anthropogenic carbon uptake from the atmosphere and thermodynamic, air-sea gas exchange processes in different water mass source areas account for the isotopic depletion. Here we evaluate the efficacy of using a concurrent nutrient-?13C strategy to separate these two effects, with the goal of improving estimates of anthropogenic carbon uptake over the course of the Industrial Revolution. In depth profiles from the sea surface to 2500 m at four stations across the California Current (42°N), nitrate, rather than phosphate, is best correlated to ?13CDIC providing the best choice for this experiment. On the basis of an assumption of no anthropogenic carbon in North Pacific Deep Waters between 1000-2500 m depth (potential densities, ?? ˜ 27.3-27.7), the "anthropogenic— preanthropogenic" carbon isotope shift (??13Ca-p) in near-surface waters of the northeast Pacific is inferred to be -0.62 ± 0.17‰, while the thermodynamic air-sea gas exchange signature is estimated at -0.48 ± 0.17‰. Values of ??13Ca-p (similar to the regional patterns of ?14C and Tritium penetration) approach zero for ?? > 26.8, indicating little penetration of anthropogenic carbon into the North Pacific Intermediate Water or the upper North Pacific Deep Water. Our results suggest an upper North Pacific sink of anthropogenic carbon over the past ˜200 years that is ˜40% greater than that estimated for the interval between ˜1970 and ˜1990 by Quay et al., [1992]. Our estimate of the North Pacific inventory of anthropogenic carbon, added to published estimates from the North Atlantic and Indian Ocean, is smaller than model predictions of the total carbon sink, suggesting that a significant portion of anthropogenic carbon enters the deep sea via the Southern Ocean.

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

    PubMed Central

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

    2009-01-01

    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

  2. Ecotoxicology of tropical marine ecosystems

    Microsoft Academic Search

    Esther C. Peters; Nancy J. Gassman; Julie C. Firman; Robert H. Richmond; Elizabeth A. Power

    1997-01-01

    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

  3. Carbon dioxide and terrestrial ecosystems

    Microsoft Academic Search

    G. W. Koch; H. A. Mooney

    1996-01-01

    This book is a summary of the current research which addresses the effects of elevated carbon dioxide on terrestrial ecosystems and an identification of significant unresolved issues. Chapters address the carbon dioxide effects on trees and forests, unmanaged herbaceous ecosystems, and crops. Included are experimental studies, conceptual models, general mathematical models, dynamic simulation models.

  4. Land use change and effects on water quality and ecosystem health in the Lake Tahoe basin, Nevada and California: year-1 progress

    USGS Publications Warehouse

    Forney, William; Raumann, Christian G.; Minor, T.B.; Smith, J.L.; Vogel, John; Vitales, Robert

    2002-01-01

    As part of the requirements for the Geographic Research and Applications Prospectus grants, this Open-File Report is the second of two that resulted from the first year of the project. The first Open-File Report (OFR 01-418) introduced the project, reviewed the existing body of literature, and outlined the research approach. This document will present an update of the research approach and offer some preliminary results from multiple efforts, specifically, the production of historical digital orthophoto quadrangles, the development of the land use/land cover (LULC) classification system, the development of a temporal transportation layer, the classification of anthropogenic cover types from the IKONOS imagery, a preliminary evaluation of landscape ecology metrics (quantification of spatial and temporal patterns of ecosystem structure and function with appropriate indices) and their utility in comparing two LULC systems, and a new initiative in community-based science and facilitation.

  5. 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)

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

    2008-12-01

    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.

  6. Is restoring an ecosystem good for your health?

    PubMed

    Speldewinde, P C; Slaney, D; Weinstein, P

    2015-01-01

    It is well known that the degradation of ecosystems can have serious impacts on human health. There is currently a knowledge gap on what impact restoring ecosystems has on human health. In restoring ecosystems there is a drive to restore the functionality of ecosystems rather than restoring ecosystems to 'pristine' condition. Even so, the complete restoration of all ecosystem functions is not necessarily possible. Given the uncertain trajectory of the ecosystem during the ecosystem restoration process the impact of the restoration on human health is also uncertain. Even with this uncertainty, the restoration of ecosystems for human health is still a necessity. PMID:25261817

  7. 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...

  8. Obscuring ecosystem function with application of the ecosystem services concept.

    PubMed

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

    2010-02-01

    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

  9. Managing an NFC Ecosystem

    Microsoft Academic Search

    Gerald Madlmayr; Josef Langer; Josef Scharinger

    2008-01-01

    Whereas several NFC trials are already established around the world, currently there are no mass rolls out yet. This is due to several technical as well as administrative issues that have to be dealt with before rolling out such a system. In this paper we present an approach for managing the B2B relations in an near field communication (NFC) ecosystem

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

    PubMed

    Jara-Marini, M E; Tapia-Alcaraz, J N; Dumer-Gutiérrez, J A; García-Rico, L; García-Hernández, J; Páez-Osuna, F

    2013-02-01

    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 México. 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

  11. The Impact of Imported Water on Hardwoods Range Ecosystems1

    E-print Network

    Standiford, Richard B.

    Clarita Valley, creating entirely new types of woodland ecosystems along the wildland/urban interface fever, and Malaria. 1 An abbreviated version of this paper was presented at the Sixth California Oak

  12. Rapid warming of Large Marine Ecosystems

    NASA Astrophysics Data System (ADS)

    Belkin, Igor M.

    2009-04-01

    The need to understand local effects of global climate change is most urgent in the Large Marine Ecosystems (LMEs) since marine ecosystem-based management requires information on the LME scale. Reported here is a study of sea surface temperature (SST) change in the World Ocean LMEs in 1957-2006 that revealed strong regional variations in the rate of SST change. The rapid warming in 1982-2006 was confined to the Subarctic Gyre, European Seas, and East Asian Seas. These LMEs warmed at rates 2-4 times the global mean rate. The most rapid warming was observed in the land-locked or semi-enclosed European and East Asian Seas (Baltic Sea, North Sea, Black Sea, Japan Sea/East Sea, and East China Sea) and also over the Newfoundland-Labrador Shelf. The Indian Ocean LMEs’ warming was slow, while two major upwelling areas - California and Humboldt Currents - experienced a slight cooling. The Subarctic Gyre warming was likely caused by natural variability related to the North Atlantic Oscillation. The extremely rapid surface warming in the enclosed and semi-enclosed European and East Asian Seas surrounded by major industrial/population agglomerations may have resulted from the observed terrestrial warming directly affecting the adjacent coastal seas. Regions of freshwater influence in the European and East Asian Seas seem to play a special role in modulating and exacerbating global warming effects on the regional scale.

  13. 77 FR 24441 - Approval and Promulgation of Implementation Plans; California; Revisions to the California State...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-24

    ...California State Implementation Plan Pesticide Element AGENCY: U.S. Environmental Protection...approve several revisions to the Pesticide Element of the California state implementation...The Current California SIP Pesticide Element and Description of the Proposed...

  14. Chemical Speciation of Sulfur in Marine Cloud Droplets and Particles: Analysis of Individual Particles from Marine Boundary Layer over the California Current

    SciTech Connect

    William R. Wiley Environmental Sciences Laboratory, Pacific Northwest National Laboratory; Gilles, Mary K; Hopkins, Rebecca J.; Desyaterik, Yury; Tivanski, Alexei V.; Zaveri, Rahul A.; Berkowitz, Carl M.; Tyliszczak, Tolek; Gilles, Mary K.; Laskin, Alexander

    2008-03-12

    Detailed chemical speciation of the dry residue particles from individual cloud droplets and interstitial aerosol collected during the Marine Stratus Experiment (MASE) was performed using a combination of complementary microanalysis techniques. Techniques include computer controlled scanning electron microscopy with energy dispersed analysis of X-rays (CCSEM/EDX), time-of-flight secondary ionization mass spectrometry (TOF-SIMS), and scanning transmission X-ray microscopy with near edge X-ray absorption fine structure spectroscopy (STXM/NEXAFS). Samples were collected at the ground site located in Point Reyes National Seashore, approximately 1 km from the coast. This manuscript focuses on the analysis of individual particles sampled from air masses that originated over the open ocean and then passed through the area of the California current located along the northern California coast. Based on composition, morphology, and chemical bonding information, two externally mixed, distinct classes of sulfur containing particles were identified: chemically modified (aged) sea salt particles and secondary formed sulfate particles. The results indicate substantial heterogeneous replacement of chloride by methanesulfonate (CH3SO3-) and non-sea salt sulfate (nss-SO42-) in sea-salt particles with characteristic ratios of nss-S/Na>0.10 and CH3SO3-/nss-SO42->0.6.

  15. Current progress in using multiple electromagnetic indicators to determine location, time, and magnitude of earthquakes in California and Peru (Invited)

    NASA Astrophysics Data System (ADS)

    Bleier, T. E.; Dunson, C.; Roth, S.; Heraud, J.; Freund, F. T.; Dahlgren, R.; Bryant, N.; Bambery, R.; Lira, A.

    2010-12-01

    Since ultra-low frequency (ULF) magnetic anomalies were discovered prior to the 1989 Loma Prieta, Ca. M7.0 earthquake, QuakeFinder, a small R&D group based in Palo Alto California has systematically monitored ULF magnetic signals with a network of 3-axis induction magnetometers since 2000 in California. This raw magnetometer data was collected at 20-50 samples per sec., with no preprocessing, in an attempt to collect an accurate time history of electromagnetic waveforms prior to, during, and after large earthquakes within 30 km. of these sensors. Finally in October 2007, the QuakeFinder team observed a series of strange magnetic pulsations at the Alum Rock, California site, 14 days prior to M5.4 earthquake. These magnetic signals observed were relatively short, random pulsations, not continuous waveform signals like Pc1 or Pc3 micropulsations. The magnetic pulses have a characteristic uni-polar shapes and 0.5 sec. to 30 sec. durations, much longer than lightning signals. In May of 2010, very similar pulses were observed at Tacna, Peru, 13 days prior to a M6.2 earthquake, using a QuakeFinder station jointly operated under collaboration with the Catholic University in Lima Peru (PUCP). More examples of these pulsations were sought, and a historical review of older California magnetic data discovered fewer but similar pulsations occurred at the Hollister, Ca. site operated by UC Berkeley (e.g. San Juan Bautista M5.1 earthquake on August 12, 1998). Further analysis of the direction of arrival of the magnetic pulses showed an interesting “azimuth clustering” observed in both Alum Rock, Ca. and Tacna, Peru data. The complete time series of the Alum Rock data allowed the team to analyze subsequent changes observed in magnetometer “filter banks” (0.001 Hz to 10 Hz filter bands, similar to those used by Fraser-Smith in 1989), but this time using time-adjusted limits based on time of day, time of year, Kp, and site background noise. These site-customized limits showed similar increases in 30 minute averaged energy excursions, but the 30 minute averages had a disadvantage in that they reduced the signal to noise ratio over the individual pulse counting method. In other electromagnetic monitoring methods, air conductivity instrumentation showed major changes in positive air-borne ions observed near the Alum Rock and Tacna sites, peaking during the 24 hours prior to the earthquake. The use of GOES (geosynchronous) satellite infra red (IR) data showed that an unusual apparent “night time heating” occurred in an extended area within 40+ km. of the Alum Rock site, and this IR signature peaked around the time of the magnetic pulse count peak. The combination of these 3 indicators (magnetic pulse counts, air conductivity, and IR night time heating) may be the start in determining the time (within 1-2 weeks), location (within 20-40km) and magnitude (within +/- 1 increment of Richter magnitude) of earthquake greater than M5.4

  16. Classifying Mediterranean Ecosystems in the Mediterranean Rim Countries and in

    E-print Network

    Standiford, Richard B.

    Classifying Mediterranean Ecosystems in the Mediterranean Rim Countries and in Southwestern U.S.A.1 of Mediterranean-type Ecosystems, June 22-26, 1981, San Diego, California. 2 Université d'Aix-Marseille III, Centre. It is of interest to compare the methods used in the countries bordering the Medi- terranean Sea

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

    E-print Network

    Ekstrom, Julia A.

    2008-01-01

    ocean acidification) impacts kelp gametophytes Acidification (reduced pH) impacts calcification required for making calcium carbonate shells.ocean acidification impacts the fitness of calcifying plankton in two major mechanisms – decreased availability of carbonate for producing shells

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

    E-print Network

    Kurapov, Alexander

    Research Theme: Theme 3 ­ Ocean-Atmosphere Fields and Fluxes Related NOAA Goal from the NOAA Strategic Plan://www.biomecardio.com/matlab/hmf.html), which was found to effectively reduce noise in the daily fields while maintaining features and detail

  19. A review of current practices and the future for deep well injection in the upper Miocene Stevens sand, Kern County, California

    SciTech Connect

    Kiser, S.C.; Chenot, D.W. (WZI, Inc., Bakersfield, CA (United States))

    1991-02-01

    Waste-water disposal is a major concern of the petroleum business, especially because of complications associated with many produced-water surface-impoundment percolation facilities. In the San Joaquin Valley, California, the current environmental regulations protecting the potentially usable groundwaters are stringent. the Stevens has significant potential as a disposal zone that may offer considerable capacity when the project is designed using proper geologic and engineering studies. The Stevens sands are well known for their oil-producing capabilities, however, not much has been published regarding its suitability as a zone for deep well injection. Conditions that make the Stevens potentially suitable include (1) adequate confinement providing geologic separation from the groundwater sources in the basin, (2) storage capacity, and (3) large areal extent. Because the search for acceptable disposal options is becoming critical, the current class II disposal options is becoming critical, the current class II disposal activities in the Stevens sands were reviewed and the areas offering the greatest future potential were identified. The authors then discuss class II disposal projects in Stevens sands in the West Bellevue and Midway Sunset oil fields and estimate the ultimate basin-wide disposal capacity of the Stevens.

  20. Marine Ecosystems

    NSDL National Science Digital Library

    New Jersey

    2006-01-01

    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.

  1. Status of the Sierra Nevada: the Sierra Nevada Ecosystem Project

    USGS Publications Warehouse

    Erman, Don C., (Edited By); SNEP team

    1997-01-01

    The Sierra Nevada ecosystem project was requested by Congress in the Conference Report for Interior and related Agencies 1993 Appropriation Act, which authorized funds for a scientific review of the remaining old growth in the national forests of the Sierra Nevada in California, and for a study of the entire Sierra Nevada ecosystem by an independent panel of scientists, with expertise in diverse areas related to this issue. This CD-ROM is a digital version of the set of reports titled 'Sierra Nevada Ecosystem Project, final report to Congress' published in paper form by the Centers for Water and Wildland Resources of the University of California, Davis.

  2. 75 FR 11555 - Notice of Public Meeting: Northeast California Resource Advisory Council and Subcommittee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-11

    ...California Resource Advisory Council and its Sage Steppe Ecosystem Subcommittee will meet as indicated below. DATES...for implementing projects under the Sage Steppe Ecosystem Restoration Strategy. Agenda topics for the full RAC...

  3. How soil moisture, rain pulses, and growth alter the response of ecosystem respiration to temperature

    Microsoft Academic Search

    Liukang Xu; Dennis D. Baldocchi; Jianwu Tang

    2004-01-01

    In this paper, we analyzed 3 years of carbon flux data from continuous eddy covariance measurements to investigate how soil moisture, rain pulses, and growth alter the response of ecosystem respiration to temperature. The data were acquired over an annual grassland and from the grass understory of an oak\\/grass savanna ecosystem in California. We observed that ecosystem respiration was an

  4. Interpreting stable and unstable ecosystem model behaviour

    NASA Astrophysics Data System (ADS)

    Pietsch, S. A.

    2009-04-01

    Large-scale ecosystem models describe the fluxes of energy and matter within terrestrial ecosystem, using mechanistic descriptions of ecosystem processes such as photosynthesis, decomposition, mineralization, transpiration, evaporation, net primary production or net ecosystem carbon exchange. Currently, this type of ecosystem models is the main tool for analysing the carbon balance of terrestrial ecosystem under scenarios of climate change. In this paper model simulations for three different ecosystems (Scots pine, Cembran pine and Common beech forest ecosystems) are analysed using the attractors of model behaviour, which are reconstructed from quasi-periodic model outputs. Stable and unstable attractor configurations are discussed according to (i) their ecological interpretation and (ii) the implications of the respective attractor configurations on predictive power of model outputs. The results show that large-scale ecosystem models may be used to: (i) determine the amount of information needed to model ecosystem behaviour, (ii) estimate the current resilience status of the modelled ecosystem, and (iii) detect situations where model application delivers meaningless results.

  5. Air-sea CO2 fluxes in the near-shore and intertidal zones influenced by the California Current

    NASA Astrophysics Data System (ADS)

    Reimer, Janet J.; Vargas, Rodrigo; Smith, Stephen V.; Lara-Lara, Ruben; Gaxiola-Castro, Gilberto; Martín Hernández-Ayón, J.; Castro, Angel; Escoto-Rodriguez, Martin; Martínez-Osuna, Juan

    2013-10-01

    The study of air-sea CO2 fluxes (FCO2) in the coastal region is needed to better understand the processes that influence the direction and magnitude of FCO2 and to constrain the global carbon budget. We implemented a 1 year (January through December 2009) paired study to measure FCO2 in the intertidal zone (the coastline to 1.6 km offshore) and the near-shore (˜3 km offshore) off the north-western coast of Baja California (Mexico); a region influenced by year-round upwelling. FCO2 was determined in the intertidal zone via eddy covariance; while in the near-shore using mooring buoy sensors then calculated with the bulk method. The near-shore region was a weak annual net source of CO2 to the atmosphere (0.043 mol CO2 m-2 y-1); where 91% of the outgassed FCO2 was contributed during the upwelling season. Sea surface temperature (SST) and ?pCO2 (from upwelling) showed the strongest relationship with FCO2 in the near-shore, suggesting the importance of meso-scale processes (upwelling). FCO2 in the intertidal zone were up to four orders of magnitude higher than FCO2 in the near-shore. Wind speed showed the strongest relationship with FCO2 in the intertidal zone, suggesting the relevance of micro-scale processes. Results show that there are substantial spatial and temporal differences in FCO2 between the near-shore and intertidal zone; likely a result of heterogeneity. We suggest that detailed spatial and temporal measurements are needed across the coastal oceans and continental margins to better understand the mechanisms which control FCO2, as well as reduce uncertainties and constrain regional and global ocean carbon balances.

  6. 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

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

    2003-01-01

    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.

  7. Comparison of shelf currents off central California prior to and during the 1997-1998 El Nino

    USGS Publications Warehouse

    Ryan, H.F.; Noble, M.A.

    2005-01-01

    Moored current, temperature, salinity, and pressure data were collected at three sites that transect the narrow continental shelf offshore of Davenport, CA, starting in August 1996 and continuing to the spring of 1998. This data set allowed a comparison of oceanographic conditions prior to (8/96-3/97) and during (8/97-3/98) the last major El Nin??o. During this El Nin??o, mean temperatures over the 8-month time period were about 3??C warmer than during the prior year at all of the sites. Correlations between near-surface and near-bottom temperatures, and between near-surface temperature and wind stress decreased during the El Nin??o compared to conditions the year before. The mean alongshore currents were more strongly poleward during El Nin??o at sites over the mid-shelf and near the shelf break. There was a general tendency for the energy in alongshore currents to move toward lower frequencies during the El Nin??o, particularly at the sites farther offshore. The processes that forced the shelf flows changed in relative importance throughout the study. The local alongshore wind stress was less important in driving shelf currents during the El Nin??o when much of the wind-induced upwelling was confined to less than 5 km of the coast. The observed strong poleward shelf currents on the mid- to outer-shelf were not clearly tied to local forcing, but were remotely driven, most likely by slope currents. The response of the Davenport shelf to an El Nin??o event may differ from other areas since the shelf is narrow, the wind forcing is weaker than areas to the north and south, and the shelf may be at times isolated by fronts that form at strong upwelling centers. In the winter, strong storm-related winds are important in driving currents at periods not only in the synoptic wind band, but also for periods on the order of 20 d and longer.

  8. 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...

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

    USGS Publications Warehouse

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

    2012-01-01

    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.

  10. Terrestrial Ecosystem Adaptation

    E-print Network

    Mills, L. Scott

    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

  11. I Spy an Ecosystem

    NSDL National Science Digital Library

    Dr. Biology

    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

  12. Population genetic responses of the planktonic copepod Metridia pacifica to a coastal eddy in the California Current

    NASA Astrophysics Data System (ADS)

    Bucklin, Ann

    1991-08-01

    Despite the intermixing that planktonic populations might be expected to experience in the ocean's fluid regime, zooplankton species may be subdivided across their range into genetically distinct populations. This subdivision, or population genetic structure, may be generated by the interplay of biological processes (reproduction, dispersal, differential mortality) and physical forces governing planktonic distributions. Significant population genetic structure in the planktonic copepod Metridia pacifica occurred during a period of upwelling in the coastal transition zone off the west coast of the United States during April and May 1987. During this period a coastal eddy of saline, recently upwelled water was bordered by a southward flowing current stream; offshore waters were nutrient poor and slower flowing. Metridia pacifica was the most abundant copepod in zooplankton samples collected in this domain; the species was sufficiently abundant in 16 samples to allow genetic analysis. Individual copepods were assayed for allozymic variability by polyacrylamide gel electrophoresis. The samples were genetically heterogeneous (by a contingency chi-square analysis of allozymic frequencies). The genetic differentiation of the samples was characteristic of geographically separated conspecific populations. Cladistic (tree building) analyses were used to visualize the genetic relatedness of the 16 samples, based on the similarity of allozymic frequencies. This analysis resulted in two heterogeneous groups (of five and six samples each) and five anomalous samples that neither constituted a third group nor belonged to the two groups. Overlay of these groupings on the dynamic height topographies showed a concordance between the population genetic and oceanographic structures. Five of the six offshore samples belonged to one group; the five samples of the other group were found either in the eddy (two of three central eddy samples) or in the current jet. The remaining five samples were scattered in nearshore regions or in the frontal region between the eddy and offshore. The division of the samples into eddy and offshore groups may result from redistribution by currents of planktonic populations of different geographic origin and distinct genetic character. Thus the eddy may have entrained copepod populations originating from different source regions than the populations in offshore waters. Further genetic analysis on appropriate time and space scales will be required to determine the mechanisms generating structure in oceanic zooplankton.

  13. 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

    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

    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.

  14. Results from a three-dimensional, nested biological-physical model of the California Current System and comparisons with statistics from satellite imagery

    NASA Astrophysics Data System (ADS)

    Powell, Thomas M.; Lewis, Craig V. W.; Curchitser, Enrique N.; Haidvogel, Dale B.; Hermann, Albert J.; Dobbins, Elizabeth L.

    2006-07-01

    A three-dimensional model of the California Current System (CCS) from 35°N to 48°N extending offshore to 134°W is coupled with a four-component trophic model. The model reproduces many conspicuous characteristics in the CCS, including: complex, filamentary, mesoscale surface features seen in the pigment and temperature from satellite imagery; wind-driven coastal upwelling at appropriate spatial and temporal scales; and the close correlation between prominent features seen in pigment and those in temperature observed by satellites (Abbott and Zion, 1985). Statistical estimates of the characteristic spatial scales of variability, as calculated from the coupled, nested model, agree with those previously estimated from satellite images (for both surface temperature and pigment (Denman and Abbott, 1988, 1994)). Model estimates of the characteristic temporal scales of variability, from decorrelation times, agree with those previously estimated from satellite images. Typical model decorrelation times lie between 2 and 4 days, in agreement with calculations from earlier sequences of (Coastal Zone Color Scanner (CZCS) and advanced very high resolution radiometer (AVHRR)) satellite images (Denman and Abbott, 1988, 1994).

  15. ECOSYSTEM ECOLOGY -ORIGINAL PAPER Increasing donor ecosystem productivity decreases terrestrial

    E-print Network

    Rosemond, Amy Daum

    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

  16. VANET security research and development ecosystem

    Microsoft Academic Search

    Irshad Ahmed Sumra; Halabi Hasbullah; Jamalul-lail Ab Manan

    2011-01-01

    Every year thousands of people are seriously injured or die in road accidents over the globe. Traffic jam and road accidents are major problems in the current traffic system. These problems directly affect human lives at the road. In this paper, we present the Vehicular ad hoc network (VANET) Security R&D Ecosystem is discussed. The R&D Ecosystem can be divided

  17. PRESERVING BIODIVERSITY: SPECIES, ECOSYSTEMS, OR LANDSCAPES?

    Microsoft Academic Search

    JERRY F. FRANKLIN

    1993-01-01

    Efforts to preserve biological diversity must focus increasingly at the ecosystem level because of the immense number of species, the majority of which are currently unknown. An ecosystem approach is also the only way to conserve processes and habitats (such as forest canopies, belowground habitats, and hyporheic zones) that, with their constituent species, are poorly known. Continued concern with species

  18. [Comprehensive assessment of urban ecosystem health].

    PubMed

    Sang, Yanhong; Chen, Xingeng; Wu, Renhai; Peng, Xiaochun

    2006-07-01

    Ecosystem health is one of the research hotspots in ecology. This paper discussed the concept of urban ecosystem health, and from the viewpoint of complex ecosystem, presented a new method and a calculation model for the comprehensive assessment of urban ecosystem health to overcome the current researches shortcomings. The application of the method and model in Foshan City of Guangdong Province showed that the assessment results could reflect not only the overall health status of the city, but also the relative health level of the city's sub-systems. PMID:17044507

  19. 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

    Grant Kaye; Jim Cole; Andrew King; David Johnston

    2009-01-01

    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 100 m tall dacite\\u000a dome on Mammoth Mountain

  20. 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.

  1. A Decade of Ecosystems

    Microsoft Academic Search

    Stephen R Carpenter; Monica G. Turner

    2007-01-01

    Ten years ago, Ecosystems was introduced as a ‘‘substrate for primary succession of the discipline‘‘ (Carpenter and Turner 1998). We envisioned Ecosystems as an arena for new ways of thinking and new kinds of progress in ecosystem science. We suggested four frontiers that seemed particularly important at that time. ‘‘People and ecosystems‘‘ addressed the study of social-ecological systems, including pressing

  2. European perspective of ecosystem services and related policies.

    PubMed

    Dunbar, Martha Bonnet; Panagos, Panos; Montanarella, Luca

    2013-04-01

    In this article, we focus on the importance of terrestrial ecosystems and the services they provide. European Union policies, contributing to the conservation and maintenance of ecosystem services in Europe are discussed and their current impacts briefly reviewed in the light of the main challenges that European ecosystems might face in the near future. PMID:23359571

  3. Functional diversity governs ecosystem response to nutrient enrichment

    Microsoft Academic Search

    Florence D. Hulot; Gérard Lacroix; Françoise Lescher-Moutoué; Michel Loreau

    2000-01-01

    The relationship between species diversity and ecosystem functioning is a central topic in ecology today. Classical approaches to studying ecosystem responses to nutrient enrichment have considered linear food chains. To what extent ecosystem structure, that is, the network of species interactions, affects such responses is currently unknown. This severely limits our ability to predict which species or functional groups will

  4. An E-learning Ecosystem Based on Cloud Computing Infrastructure

    Microsoft Academic Search

    Bo Dong; Qinghua Zheng; Jie Yang; Haifei Li; Mu Qiao

    2009-01-01

    Recently the research community has believed that an e-learning ecosystem is the next generation e- learning. However, the current models of e-learning ecosystems lack the support of underlying infrastructures, which can dynamically allocate the required computation and storage resources for e- learning ecosystems. Cloud computing is a promising infrastructure which provides computation and storage resources as services. Hence, this paper

  5. Measurements of nitrite production and nitrite-producing organisms in and around the primary nitrite maximum in the central California Current

    NASA Astrophysics Data System (ADS)

    Santoro, A. E.; Sakamoto, C. M.; Smith, J. M.; Plant, J. N.; Gehman, A. L.; Worden, A. Z.; Johnson, K. S.; Francis, C. A.; Casciotti, K. L.

    2013-03-01

    Nitrite (NO2-) is a substrate for both oxidative and reductive microbial metabolism. NO2- accumulates at the base of the euphotic zone in oxygenated, stratified open ocean water columns, forming a feature known as the primary nitrite maximum (PNM). Potential pathways of NO2- production include the oxidation of ammonia (NH3) by ammonia-oxidizing bacteria or archaea and assimilatory nitrate (NO3-) reduction by phytoplankton or heterotrophic bacteria. Measurements of NH3 oxidation and NO3- reduction to NO2- were conducted at two stations in the central California Current in the eastern North Pacific to determine the relative contributions of these processes to NO2- production in the PNM. Sensitive (< 10 nmol L-1), high-resolution measurements of [NH4+] and [NO2-] indicated a persistent NH4+ maximum overlying the PNM at every station, with concentrations as high as 1.5 ?mol L-1. Within and just below the PNM, NH3 oxidation was the dominant NO2- producing process with rates of NH3 oxidation of up to 50 nmol L-1 d-1, coinciding with high abundances of ammonia-oxidizing archaea. Though little NO2- production from NO3- was detected, potentially nitrate-reducing phytoplankton (photosynthetic picoeukaryotes, Synechococcus, and Prochlorococcus) were present at the depth of the PNM. Rates of NO2- production from NO3- were highest within the upper mixed layer (4.6 nmol L-1 d-1) but were either below detection limits or 10 times lower than NH3 oxidation rates around the PNM. One-dimensional modeling of water column NO2- profiles supported direct rate measurements of a net biological sink for NO2- just below the PNM. Residence time estimates of NO2- within the PNM were similar at the mesotrophic and oligotrophic stations and ranged from 150-205 d. Our results suggest the PNM is a dynamic, rather than relict, feature with a source term dominated by ammonia oxidation.

  6. The State of Ecosystems

    NSDL National Science Digital Library

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

    2005-08-01

    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.

  7. 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...

  8. 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...

  9. Using Seabird Habitat Modeling to Inform Marine Spatial Planning in Central California’s National Marine Sanctuaries

    PubMed Central

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

    2013-01-01

    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

  10. 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.

  11. Terrestrial ecosystems and climatic change

    SciTech Connect

    Emanuel, W.R. (Oak Ridge National Lab., TN (USA)); Schimel, D.S. (Colorado State Univ., Fort Collins, CO (USA). Natural Resources Ecology Lab.)

    1990-01-01

    The structure and function of terrestrial ecosystems depend on climate, and in turn, ecosystems influence atmospheric composition and climate. A comprehensive, global model of terrestrial ecosystem dynamics is needed. A hierarchical approach appears advisable given currently available concepts, data, and formalisms. The organization of models can be based on the temporal scales involved. A rapidly responding model describes the processes associated with photosynthesis, including carbon, moisture, and heat exchange with the atmosphere. An intermediate model handles subannual variations that are closely associated with allocation and seasonal changes in productivity and decomposition. A slow response model describes plant growth and succession with associated element cycling over decades and centuries. These three levels of terrestrial models are linked through common specifications of environmental conditions and constrain each other. 58 refs.

  12. Coral Reef Ecosystems: Ecosystems in Crisis

    NSDL National Science Digital Library

    National Science Teachers Association (NSTA)

    2007-03-28

    This Science Object is the fourth of four Science Objects in the Coral Reef Ecosystems SciPack. It explores the natural and human causes of ecosystem stress. Human beings live near coral ecosystems and use them in a variety of ways. Increasing amounts of stress is brought on these ecosystems as humans continue to modify the surrounding environment as a result of population growth, technology, and consumption. Human destruction of habitats through direct harvesting, pollution, atmospheric changes, and other factors is threatening the stability and overall health of many coral reefs. Human activities may also exacerbate the impact of natural disturbances on coral reefs or compromise the ability of the reef to recover from events such as hurricanes, tsunamis, or disease. Learning Outcomes:? 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.

  13. Ecosystem health: I. Measuring ecosystem health

    NASA Astrophysics Data System (ADS)

    Schaeffer, David J.; Herricks, Edwin E.; Kerster, Harold W.

    1988-07-01

    Ecosystem analysis has been advanced by an improved understanding of how ecosystems are structured and how they function. Ecology has advanced from an emphasis on natural history to consideration of energetics, the relationships and connections between species, hierarchies, and systems theory. Still, we consider ecosystems as entities with a distinctive character and individual characteristics. Ecosystem maintenance and preservation form the objective of impact analysis, hazard evaluation, and other management or regulation activities. In this article we explore an approach to ecosystem analysis which identifies and quantifies factors which define the condition or state of an ecosystem in terms of health criteria. We relate ecosystem health to human/nonhuman animal health and explore the difficulties of defining ecosystem health and suggest criteria which provide a functional definition of state and condition. We suggest that, as has been found in human/nonhuman animal health studies, disease states can be recognized before disease is of clinical magnitude. Example disease states for ecosystems are functionally defined and discussed, together with test systems for their early detection.

  14. California Dust

    Atmospheric Science Data Center

    2014-05-15

    ... when forced through narrow canyons and mountain passes. Due to Southern California's uneven terrain, the strength of the winds varies ... MISR category:  gallery date:  Feb 9, 2002 Images:  California Dust ...

  15. Financing Postsecondary Education in California.

    ERIC Educational Resources Information Center

    California State Legislature, Sacramento. Joint Committee on the Master Plan for Higher Education.

    This document presents an overview of the financial aspects of postsecondary educational institutions in California and suggests some recommendations for the alleviation of financial problems. The study consisted of extensive research of the current literature on financing, gathering key data on the California system, reviewing the pertinent…

  16. 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

    Root Barrier; Extension Pau

    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

  17. Sustaining the Landscape: A Method for Comparing Current and Desired Future Conditions of Forest Ecosystems in the North Cumberland Plateau and Mountains

    SciTech Connect

    Druckenbrod, D.L.

    2004-12-22

    This project initiates an integrated-landscape conservation approach within the Northern Cumberlands Project Area in Tennessee and Kentucky. The mixed mesophytic forests within the Cumberland Plateau and Mountains are among the most diverse in North America; however, these forests have been impacted by and remain threatened from changes in land use across this landscape. The integrated-landscape conservation approach presented in this report outlines a sequence of six conservation steps. This report considers the first three of these steps in two, successive stages. Stage 1 compares desired future conditions (DFCs) and current prevailing conditions (CPCs) at the landscape-scale utilizing remote sensing imagery, remnant forests, and descriptions of historical forest types within the Cumberland Plateau. Subsequently, Stage 2 compares DFCs and CPCs for at-risk forest types identified in Stage 1 utilizing structural, compositional, or functional attributes from USFS Forest Inventory and Analysis data. Ecological indicators will be developed from each stage that express the gaps between these two realizations of the landscape. The results from these first three steps will directly contribute to the final three steps of the integrated-landscape conservation approach by providing guidance for the generation of new conservation strategies in the Northern Cumberland Plateau and Mountains.

  18. 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

  19. Future climate change and upwelling in the California Current Mark A. Snyder, Lisa C. Sloan, Noah S. Diffenbaugh, and Jason L. Bell

    E-print Network

    Snyder, Mark A.

    and McGowan, 1995]. [5] The hypothesis of Bakun [1990] that increased green- house gas forcing will lead intensifying as atmospheric green- house gas concentrations have grown over the past few decades [Mendelssohn marine fauna. Changes in upwelling can have a profound effect on a variety of ecosystems, and variations

  20. Sagebrush Ecosystem Conservation and Management

    E-print Network

    Aldridge, Cameron

    Sagebrush Ecosystem Conservation and Management: Ecoregional Assessment Tools and Models SagebrushEcosystemConservationandManagement Hanser Leu Knick Aldridge Sagebrush Ecosystem Conservation of the remaining strongholds of the sagebrush ecosystem. However, like most sagebrush habitats, threats

  1. 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

  2. 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

  3. Biodiversity regulates ecosystem predictability

    Microsoft Academic Search

    Patricia M. Harris; Peter J. Morin

    1997-01-01

    1-6 . Here we describe a previously unrecognized effect of biodiversity on ecosystem predictability, where predictability is inversely related to temporal and spatial variation in ecosystem properties. By manipulating biodiversity in aquatic microbial communities, we show that one process, ecosystem respiration, becomes more predictable as biodiversity increases. Analysis of similar patterns extracted from other studies 2,3,6 indicates that biodiversity also

  4. The polluted ecosystem game

    Microsoft Academic Search

    W. A. Brock; W. D. Dechert

    2008-01-01

    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

  5. 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 ...

  6. California State Waters Map Series: offshore of Salt Point, California

    USGS Publications Warehouse

    Johnson, Samuel Y.; Dartnell, Peter; Golden, Nadine E.; Hartwell, Stephen R.; Erdey, Mercedes D.; Greene, H. Gary; Cochrane, Guy R.; Kvitek, Rikk G.; Manson, Michael W.; Endris, Charles A.; Dieter, Bryan E.; Watt, Janet T.; Krigsman, Lisa M.; Sliter, Ray W.; Lowe, Erik N.; Chinn, John L.

    2015-01-01

    Circulation over the continental shelf in the map area is dominated by the southward-flowing California Current, the eastern limb of the North Pacific Gyre. Associated upwelling brings cool, nutrient-rich

  7. Ecosystem carbon dioxide fluxes after disturbance in forests of North America

    E-print Network

    Cohen, Ronald C.

    ecosystems. Similarly, for forests less than 100 years old, maximum uptake (g C m-2 y-1 ) was 1180 in Florida, Gainesville, Florida, USA. 6 Department of Earth, Ecological, and Environmental Sciences, University of Toledo of Earth System Science, University of California, Irvine, California, USA. 13 Canadian Forest Service

  8. Fort Collins Science Center: Ecosystem Dynamics

    USGS Publications Warehouse

    Bowen, Zack

    2004-01-01

    Many challenging natural resource management issues require consideration of a web of interactions among ecosystem components. The spatial and temporal complexity of these ecosystem problems demands an interdisciplinary approach integrating biotic and abiotic processes. The goals of the Ecosystem Dynamics Branch are to provide sound science to aid federal resource managers and use long-term, place-focused research and monitoring on federal lands to advance ecosystem science. Current studies fall into five general areas. Herbivore-Ecosystem Interactions examines the efficacy of multiple controls on selected herbivore populations and cascading effects through predator-herbivore-plant-soil linkages. Riparian Ecology is concerned with interactions among streamflow, fluvial geomorphology, and riparian vegetation. Integrated Fire Science focuses on the effects of fire on plant and animal communities at multiple scales, and on the interactions between post-fire plant, runoff, and erosion processes. Reference Ecosystems comprises long-term, place-based studies of ecosystem biogeochemistry. Finally, Integrated Assessments is investigating how to synthesize multiple ecosystem stressors and responses over complex landscapes in ways that are useful for management and planning.

  9. LINKING COMMUNITY STRUCTURE AND ECOSYSTEM FUNCTION IN AQUATIC ECOSYSTEMS DEGRADED BY MOUNTAINTOP MINING

    EPA Science Inventory

    The Clean Water Act and its subsequent amendments recognize the importance of protecting biological integrity, a concept synonymous with preserving structure and function within lotic ecosystems. This research will improve current taxonomically based risk assessment models,...

  10. California's Energy Policy: Conservation Works 

    E-print Network

    Greene, D.

    1982-01-01

    Conservation is the foundation of California's energy policy and the largest single source of the state's 'new energy supply'. Our goal is to use economic market forces and government programs to direct energy Investments away from our current...

  11. Environments and Ecosystems

    NSDL National Science Digital Library

    2014-09-18

    Students explore the biosphere and its associated environments and ecosystems in the context of creating a model ecosystem, learning along the way about the animals and resources. Students investigate different types of ecosystems, learn new vocabulary, and consider why a solid understanding of one's environment and the interdependence of an ecosystem can inform the choices we make and the way we engineer our communities. This lesson is part of a series of six lessons in which students use their growing understanding of various environments and the engineering design process, to design and create their own model biodome ecosystems.

  12. 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...

  13. 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

  14. Multi-proxy reconstructions and the power of integration across marine, terrestrial, and freshwater ecosystems. (Invited)

    NASA Astrophysics Data System (ADS)

    Black, B.

    2013-12-01

    Over the past decade, dendrochronology (tree-ring analysis) techniques have been increasingly applied to growth increments of various bivalve, fish, and coral species. In particular, the use of crossdating ensures that all increments in a dataset have assigned the correct calendar year of formation and that the resulting chronology is exactly placed in time. Such temporal alignment facilitates direct comparisons among chronologies that span diverse taxa and ecosystems, illustrating the pervasive, synchronizing influence of climate from alpine forests to the continental slope. Such an approach can be particularly beneficial to reconstructions in that each species captures climate signals from its unique 'perspective' of life history and habitat. For example, combinations of tree-ring data and chronologies for the long-lived bivalve Pacific geoduck (Panopea generosa) capture substantially more variance in regional sea surface temperatures than either proxy could explain alone. Just as importantly, networks of chronologies spanning multiple trophic levels can help identify climate variables critical to ecosystem functioning, which can then be targeted to generate most biologically relevant reconstructions possible. Along the west coast of North America, fish and bivalve chronologies in combination with records of seabird reproductive success indicate that winter sea-level pressure is closely associated with California Current productivity, which can be hind-cast over the past six centuries using coastal tree-ring chronologies. Thus, multiple proxies not only increase reconstruction skill, but also help isolate climate variables most closely linked to ecosystem structure and functioning.

  15. Natural Reserve System UNIVERSITY OF CALIFORNIA

    E-print Network

    California at Santa Cruz, University of

    Scripps Coastal Reserve Santa Barbara 29 Carpinteria Salt Marsh Reserve 30 Coal Oil Point Natural Reserve of ecosystems throughout California. Reserves offer outdoor laboratories to field scientists, classrooms without of natural reserves; no other network of field sites can match its size, scope, and ecological diversity

  16. Regional Habitat Assessment Prioritization for California Stocks

    E-print Network

    Regional Habitat Assessment Prioritization for California Stocks Report of the Southwest Regional Habitat Assessment Prioritization Working Group Kristan Blackhart, Stephen K. Brown, Bryant Chesney, E. J, MD An online version is available at: http://www.st.nmfs.noaa.gov/ecosystems/habitat

  17. Effects of ozone on ecosystems -- ecosystem indicators of concern

    SciTech Connect

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

    1998-12-31

    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.

  18. Coral Reef Ecosystems

    NSDL National Science Digital Library

    National Science Teachers Association (NSTA)

    2007-03-28

    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.

  19. JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 92, NO. C2, PAGES 1637-1654, FEBRUARY 15, 1987 Structure of the Coastal Current Field off Northern California During the

    E-print Network

    Kurapov, Alexander

    imagery and the presence of vigorous current structures including squirts (regions of intense seaward flow),eddies squirts were recurrently observed. Over the past 2 decades, moored current meters have been used to study by the upwelling. At greater depth A the alongshore currents reverse and form a poleward under- current flowing

  20. Emergy and ecosystem complexity

    NASA Astrophysics Data System (ADS)

    Ulgiati, Sergio; Brown, Mark T.

    2009-01-01

    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.

  1. Global Conservation of Biodiversity and Ecosystem Services

    NSDL National Science Digital Library

    Will Turner (University of the Philippines; World Agroforestry Center)

    2007-11-01

    This peer-reviewed article from the November 2007 issue of BioScience examines conservation strategies to preserve biodiversity and ecosystem services.Habitat destruction has driven much of the current biodiversity extinction crisis, and it compromises the essential benefits, or ecosystem services, that humans derive from functioning ecosystems. Securing both species and ecosystem services might be accomplished with common solutions. Yet it is unknown whether these two major conservation objectives coincide broadly enough worldwide to enable global strategies for both goals to gain synergy. In this article, we assess the concordance between these two objectives, explore how the concordance varies across different regions, and examine the global potential for safeguarding biodiversity and ecosystem services simultaneously. We find that published global priority maps for biodiversity conservation harbor a disproportionate share of estimated terrestrial ecosystem service value (ESV). Overlap of biodiversity priorities and ESV varies among regions, and in areas that have high biodiversity priority but low ESV, specialized conservation approaches are necessary. Overall, however, our findings suggest opportunities for safeguarding both biodiversity and ecosystem services. Sensitivity analyses indicate that results are robust to known limitations of available ESV data. Capitalizing on these opportunities will require the identification of synergies at fine scales, and the development of economic and policy tools to exploit them.

  2. Food-web constraints on biodiversity-ecosystem functioning relationships.

    PubMed

    Thébault, Elisa; Loreau, Michel

    2003-12-01

    The consequences of biodiversity loss for ecosystem functioning and ecosystem services have aroused considerable interest during the past decade. Recent work has focused mainly on the impact of species diversity within single trophic levels, both experimentally and theoretically. Experiments have usually showed increased plant biomass and productivity with increasing plant diversity. Changes in biodiversity, however, may affect ecosystem processes through trophic interactions among species as well. An important current challenge is to understand how these trophic interactions affect the relationship between biodiversity and ecosystem functioning. Here we present a mechanistic model of an ecosystem with multiple trophic levels in which plants compete for a limiting soil nutrient. In contrast to previous studies that focused on single trophic levels, we show that plant biomass does not always increase with plant diversity and that changes in biodiversity can lead to complex if predictable changes in ecosystem processes. Our analysis demonstrates that food-web structure can profoundly influence ecosystem properties. PMID:14638942

  3. Food-web constraints on biodiversity–ecosystem functioning relationships

    PubMed Central

    Thébault, Elisa; Loreau, Michel

    2003-01-01

    The consequences of biodiversity loss for ecosystem functioning and ecosystem services have aroused considerable interest during the past decade. Recent work has focused mainly on the impact of species diversity within single trophic levels, both experimentally and theoretically. Experiments have usually showed increased plant biomass and productivity with increasing plant diversity. Changes in biodiversity, however, may affect ecosystem processes through trophic interactions among species as well. An important current challenge is to understand how these trophic interactions affect the relationship between biodiversity and ecosystem functioning. Here we present a mechanistic model of an ecosystem with multiple trophic levels in which plants compete for a limiting soil nutrient. In contrast to previous studies that focused on single trophic levels, we show that plant biomass does not always increase with plant diversity and that changes in biodiversity can lead to complex if predictable changes in ecosystem processes. Our analysis demonstrates that food-web structure can profoundly influence ecosystem properties. PMID:14638942

  4. Ecosystem Services - Water Purification

    NSDL National Science Digital Library

    Science Netlinks

    2002-06-30

    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.

  5. 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.

  6. Triple check: Observations verify structural realism of an ocean ecosystem model

    NASA Astrophysics Data System (ADS)

    Santora, Jarrod A.; Sydeman, William J.; Messié, Monique; Chai, Fei; Chao, Yi; Thompson, Sarah Ann; Wells, Brian K.; Chavez, Francisco P.

    2013-04-01

    Improvements in fisheries and ecosystem management could be made if the prediction of key zooplankton, such as krill, were possible using ocean ecosystem models. To examine structural realism, hence the validity of a coupled physical-biogeochemical model, we compared measured spatiotemporal dynamics of krill and seabird abundance off California to hindcasted mesozooplankton derived from an independently designed model. Observed krill and modeled mesozooplankton (Z2) displayed latitudinal coherence but distinct longitudinal offsets, possibly related to unrealistic bathymetry in the model. Temporally, Z2, Thysanoessa spinifera (a neritic krill species) and seabird density and reproductive performance were well correlated, indicating that quantitative prediction regarding marine predators in upwelling ecosystems is within reach. Despite its basin-scale framework, the ROMS-CoSiNE model captures zooplankton and top predator dynamics regionally in the central California region, suggesting its utility for management of marine ecosystems and highlighting rapid advances that can be made through collaboration between empirical scientists and ecosystem modelers.

  7. Changes in chemistry and aggregation of a california forest soil worked by the earthworm Argilophilus papillifer eisen (megascolecidae)

    Microsoft Academic Search

    John G. McColl

    1998-01-01

    Little is known about the functional significance of earthworms in California forest ecosystems. A microcosm study of Argilophilus papillifer Eisen (Megascolecidae), a species indigenous to California, was conducted to ascertain its influence on chemical and physical properties of a California forest soil. Earthworms were incubated for 6 months in microcosms consisting of A-horizon soil and a surface layer of one

  8. Ecological Issues Related to Decommissioning of California's Offshore Production Platforms

    E-print Network

    Carr, Mark H.

    Ecological Issues Related to Decommissioning of California's Offshore Production Platforms Report offshore oil production platforms to assess the current state of knowledge and identify a research agenda................................................................................................................ 8 II.A. Review of California platforms

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

    PubMed Central

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

    2014-01-01

    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 µg 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

  10. Constraining Night Time Ecosystem Respiration by Inverse Approaches

    Microsoft Academic Search

    J. Juang; P. C. Stoy; M. B. Siqueira; G. G. Katul

    2004-01-01

    Estimating nighttime ecosystem respiration remains a key challenge in quantifying ecosystem carbon budgets. Currently, nighttime eddy-covariance (EC) flux measurements are plagued by uncertainties often attributed to poor mixing within the canopy volume, non-turbulent transport of CO2 into and out of the canopy, and non-stationarity and intermittency. Here, we explore the use of second-order closure models to estimate nighttime ecosystem respiration

  11. Are hotspots of evolutionary potential adequately protected in southern California?

    USGS Publications Warehouse

    Vandergast, A.G.; Bohonak, A.J.; Hathaway, S.A.; Boys, J.; Fisher, R.N.

    2008-01-01

    Reserves are often designed to protect rare habitats, or "typical" exemplars of ecoregions and geomorphic provinces. This approach focuses on current patterns of organismal and ecosystem-level biodiversity, but typically ignores the evolutionary processes that control the gain and loss of biodiversity at these and other levels (e.g., genetic, ecological). In order to include evolutionary processes in conservation planning efforts, their spatial components must first be identified and mapped. We describe a GIS-based approach for explicitly mapping patterns of genetic divergence and diversity for multiple species (a "multi-species genetic landscape"). Using this approach, we analyzed mitochondrial DNA datasets from 21 vertebrate and invertebrate species in southern California to identify areas with common phylogeographic breaks and high intrapopulation diversity. The result is an evolutionary framework for southern California within which patterns of genetic diversity can be analyzed in the context of historical processes, future evolutionary potential and current reserve design. Our multi-species genetic landscapes pinpoint six hotspots where interpopulation genetic divergence is consistently high, five evolutionary hotspots within which genetic connectivity is high, and three hotspots where intrapopulation genetic diversity is high. These 14 hotspots can be grouped into eight geographic areas, of which five largely are unprotected at this time. The multi-species genetic landscape approach may provide an avenue to readily incorporate measures of evolutionary process into GIS-based systematic conservation assessment and land-use planning.

  12. Current Cites

    NSDL National Science Digital Library

    With the ever-growing interest in information technology and digital initiatives and projects, the Current Cites website will be of great interest to persons working in these various fields. Edited by Roy Tennant (a librarian working at the California Digital Library in Oakland), Current Cites is a monthly publication that contains 10-15 annotated citations of the best literature currently available in the field of information technology. Of course, visitors to the site may elect to sign up to receive Current Cites every month, or they may peruse the contents of the publication back to its founding in August 1990. Equally helpful is the Bibliography On-Demand feature that allows users to construct their own bibliography culled from the Current Cites database of bibliographic citations. Additionally, the items that are freely available on the Internet are also retrieved and indexed so that users may perform an article search of the full-text of these various items.

  13. Earth on Edge: Ecosystems

    NSDL National Science Digital Library

    Janet Overton

    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.

  14. Science Sampler: Ecosystem Jenga!

    NSDL National Science Digital Library

    Diandra L. Leslie-Pelecky

    2009-09-01

    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 bal

  15. Ecosystems emerging: 1. conservation

    Microsoft Academic Search

    Bernard C. Patten; Milan Straškraba; Sven E. Jørgensen

    1997-01-01

    This second paper in the series on Ecosystems Emerging treats some properties of ecosystems derivable from the single elementary principle of conservation. These go beyond the mere balancing out of the matter and forces of nature.A brief sketch of a conservationless world is given, followed by an elementary background review of energy, matter and information. The main conservative quantities are

  16. Exploring virtual ecosystems

    Microsoft Academic Search

    Antão Vaz Almada; António Eduardo Dias; João Pedro Silva; Emanuel Marques dos Santos; Pedro José Pedrosa; António Sousa Câmara

    1996-01-01

    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

  17. Where Will Ecosystems Go?

    SciTech Connect

    Janetos, Anthony C.

    2008-09-29

    Climate-induced changes in ecosystems have been both modeled and documented extensively over the past 15-20 years. Those changes occur in the context of many other stresses and interacting factors, but it is clear that many, if not most, ecosystems are sensitive to changing climate.

  18. Environmental Biology - Ecosystems

    NSDL National Science Digital Library

    Dave McShaffrey

    This resource explains how energy and pollutants move through an ecosystem, how ecosystems are balanced and how they may be affected by human activities. Concepts described include the roles of organisms, food chains and food webs, pyramids of biomass, biological magnification, and biogeochemical cycles such as water, carbon, nitrogen, and phosphorous cycles.

  19. Ecosystem services and water economics

    E-print Network

    Hill, Jeffrey E.

    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

  20. Ecosystem Viable Yields

    E-print Network

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

    2011-01-01

    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.

  1. CONCURRENT SESSION I--Wildland Ecosystem Topics 48 USDA Forest Service Gen. Tech. Rep. PSW-GTR-158. 1995.

    E-print Network

    Standiford, Richard B.

    CONCURRENT SESSION I--Wildland Ecosystem Topics #12;48 USDA Forest Service Gen. Tech. Rep. PSW Symposium: Fire Issues and Solutions in Urban Interface and Wildland Ecosystems, February 15-17, 1994, Walnut Creek, California. 2Prescribed Fire Specialist, Western Region, USDI National Park Ser- vice, 600

  2. California Wildflowers

    NSDL National Science Digital Library

    The California Academy of Sciences's (CAS) Botany Department hosts this interesting and beautiful site on California's wildflowers. Spectacular color photographs of over 125 species of wildflowers serve as illustrations to this electronic field guide. Users may browse species by flower color (white through brown), common name (Alpine Lily to Yerba Mansa), latin name (Achillea millefolium to Zigadenus fremontii), or family name (Alismataceae through Violaceae). Additionally, floristic regions are provided in a color-coded map of California. For each species, the taxonomic identity (common, Latin, and family names), a description, photographs, and distribution information are provided. Educators and students of botany will find this site particularly useful; others will want to go see California in bloom.

  3. California Coast

    Atmospheric Science Data Center

    2014-05-15

    ... Fault on the south and the Garlock Fault on the north. To the northwest are the Sierra Nevada mountains and the agricultural fields of ... MISR category:  gallery date:  Mar 14, 2000 Images:  California Coast ...

  4. Transforming California

    NSDL National Science Digital Library

    Thomas McGuire

    2001-01-01

    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.

  5. Mechanisms of plant species impacts on ecosystem nitrogen cycling

    Microsoft Academic Search

    J. M. H. Knops; K. L. Bradley; D. A. Wedin

    2002-01-01

    Plant species are hypothesized to impact ecosystem nitrogen cycling in two distinctly different ways. First, differences in nitrogen use efficiency can lead to positive feedbacks on the rate of nitrogen cycling. Alternatively, plant species can also control the inputs and losses of nitrogen from ecosystems. Our current understanding of litter decomposition shows that most nitrogen present within litter is not

  6. Understanding the scientific software ecosystem and its impact

    E-print Network

    Howison, James

    of a scientific software ecosystem. Adding further complexity, scientific software interacts with the scientificUnderstanding the scientific software ecosystem and its impact: current and future measures James-64209 and 11-48515. Abstract Software is increasingly important to the scientific enterprise and science

  7. Rust and Beetle Interactions in Pinus albicaulis Ecosystems

    Microsoft Academic Search

    Nancy Bockino; Daniel B. Tinker

    2009-01-01

    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

  8. Quantum and Ecosystem Entropies

    NASA Astrophysics Data System (ADS)

    Kirwan, A. D.

    2008-06-01

    Ecosystems and quantum gases share a number of superficial similarities including enormous numbers of interacting elements and the fundamental role of energy in such interactions. A theory for the synthesis of data and prediction of new phenomena is well established in quantum statistical mechanics. The premise of this paper is that the reason a comparable unifying theory has not emerged in ecology is that a proper role for entropy has yet to be assigned. To this end, a phase space entropy model of ecosystems is developed. Specification of an ecosystem phase space cell size based on microbial mass, length, and time scales gives an ecosystem uncertainty parameter only about three orders of magnitude larger than Planck’s constant. Ecosystem equilibria is specified by conservation of biomass and total metabolic energy, along with the principle of maximum entropy at equilibria. Both Bose - Einstein and Fermi - Dirac equilibrium conditions arise in ecosystems applications. The paper concludes with a discussion of some broader aspects of an ecosystem phase space.

  9. Coral Reef Ecosystems: Interdependence

    NSDL National Science Digital Library

    National Science Teachers Association (NSTA)

    2006-11-01

    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.

  10. 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

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

    2010-01-01

    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

  11. CALIFORNIA ENERGY COMMISSION California Energy Commission

    E-print Network

    INDUSTRIES ASSOCIATION, COALITION FOR CLEAN AIR, DISTRIBUTED ENERGY CONSUMER ADVOCATES, ENVIRONMENT, Coalition for Clean Air, Distributed Energy Consumer Advocates, Environment California Research & PolicyCALIFORNIA ENERGY COMMISSION California Energy Commission DOCKETED /3-I"b-P-l PETITION

  12. Objects or Ecosystems? Giant Sequoia Management in National Parks

    NSDL National Science Digital Library

    David Parsons

    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.

  13. Lessons on River Ecosystems

    NSDL National Science Digital Library

    Dan Zalles

    The lesson activity titles are: What are systems? (Purpose: to have students understand what a "system" is, in the broadest sense) How is the natural environment of the tribal community a system? (Purpose: to tie what students learned during the year about the tribal community and its natural environment to the concept of what a "system" is) How did settlers of European descent change the tribe's ecosystem? (Purpose: to explore the connections between what European settlers did to the tribe's ecosystem and what the effects have been on the ecosystem) What can be done? What should be done? (Purpose: to explore and evaluate policy options for future environmental sustenance)

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

    E-print Network

    Dever, Jennifer A.

    1 Ecosystem approach to management I. "dynamic" ecosystem management v. the past "static" approach A. Past Resource Management Approach B. New ecosystem management approach C. Examples II. Using Natural Processes under Ecosystem Management A. Disturbance B. Succession C. Important types of natural

  15. Assessing niche width of endothermic fish from genes to ecosystem.

    PubMed

    Madigan, Daniel J; Carlisle, Aaron B; Gardner, Luke D; Jayasundara, Nishad; Micheli, Fiorenza; Schaefer, Kurt M; Fuller, Daniel W; Block, Barbara A

    2015-07-01

    Endothermy in vertebrates has been postulated to confer physiological and ecological advantages. In endothermic fish, niche expansion into cooler waters is correlated with specific physiological traits and is hypothesized to lead to greater foraging success and increased fitness. Using the seasonal co-occurrence of three tuna species in the eastern Pacific Ocean as a model system, we used cardiac gene expression data (as a proxy for thermal tolerance to low temperatures), archival tag data, and diet analyses to examine the vertical niche expansion hypothesis for endothermy in situ. Yellowfin, albacore, and Pacific bluefin tuna (PBFT) in the California Current system used more surface, mesopelagic, and deep waters, respectively. Expression of cardiac genes for calcium cycling increased in PBFT and coincided with broader vertical and thermal niche utilization. However, the PBFT diet was less diverse and focused on energy-rich forage fishes but did not show the greatest energy gains. Ecosystem-based management strategies for tunas should thus consider species-specific differences in physiology and foraging specialization. PMID:26100889

  16. Nutrient flows between ecosystems can destabilize simple food chains.

    PubMed

    Marleau, Justin N; Guichard, Frédéric; Mallard, François; Loreau, Michel

    2010-09-01

    Dispersal of organisms has large effects on the dynamics and stability of populations and communities. However, current metacommunity theory largely ignores how the flows of limiting nutrients across ecosystems can influence communities. We studied a meta-ecosystem model where two autotroph-consumer communities are spatially coupled through the diffusion of the limiting nutrient. We analyzed regional and local stability, as well as spatial and temporal synchrony to elucidate the impacts of nutrient recycling and diffusion on trophic dynamics. We show that nutrient diffusion is capable of inducing asynchronous local destabilization of biotic compartments through a diffusion-induced spatiotemporal bifurcation. Nutrient recycling interacts with nutrient diffusion and influences the susceptibility of the meta-ecosystem to diffusion-induced instabilities. This interaction between nutrient recycling and transport is further shown to depend on ecosystem enrichment. It more generally emphasizes the importance of meta-ecosystem theory for predicting species persistence and distribution in managed ecosystems. PMID:20600133

  17. ‘Decomposer’ Basidiomycota in Arctic and Antarctic ecosystems

    Microsoft Academic Search

    Katherine E. Ludley; Clare H. Robinson

    2008-01-01

    Current knowledge concerning ‘decomposer’ Basidiomycota in Arctic and Antarctic ecosystems is based on two sources: (a) collections and surveys of basidiomata, which have resulted in high-quality catalogues of species, although much of the species’ distribution and ecology are tentative and (b) isolations from soils and plant litter which typically result in a “low incidence of basidiomycetes” [Dowding, P., Widden, P.,

  18. Value of ecosystem hydropower service and its impact on the payment for ecosystem services.

    PubMed

    Fu, B; Wang, Y K; Xu, P; Yan, K; Li, M

    2014-02-15

    Hydropower is an important service provided by ecosystems. We surveyed all the hydropower plants in the Zagunao River Basin, Southwest China. Then, we assessed the hydropower service by using the InVEST (The Integrated Value and Tradeoff of Ecosystem Service Tools) model. Finally, we discussed the impact on ecological compensation. The results showed that: 1) hydropower service value of ecosystems in the Zagunao River Basin is 216.29 Euro/hm(2) on the average, of which the high-value area with more than 475.65 Euro/hm(2) is about 750.37 km(2), accounting for 16.12% of the whole watershed, but it provides 53.47% of the whole watershed service value; 2) ecosystem is an ecological reservoir with a great regulation capacity. Dams cannot completely replace the reservoir water conservation function of ecosystems, and has high economic and environmental costs that must be paid as well. Compensation for water conservation services should become an important basis for ecological compensation of hydropower development. 3) In the current PES cases, the standard of compensation is generally low. Cascade development makes the value of upstream ecosystem services become more prominent, reflecting the differential rent value, and the value of ecosystem services should be based on the distribution of differentiated ecological compensation. PMID:24291631

  19. Light Pollution and Ecosystems

    NSDL National Science Digital Library

    Travis Longcore (University of Southern California; )

    2010-05-20

    Artificial light at night acts as a pollutant, with significant and adverse impacts to ecosystems. It can, for example, cause disorientation or act as an unnatural stimulus to wildlife, and disrupt reproduction for many species.

  20. Self Contained Ecosystems

    NASA Technical Reports Server (NTRS)

    1985-01-01

    A self contained ecosystem developed at Jet Propulsion Laboratory is manufactured by Engineering and Research Associates. It is essentially a no-care aquarium which requires only natural or fluorescent light.

  1. THE COMPUTERIZED ECOSYSTEM

    EPA Science Inventory

    A generalized discussion of mathematical simulation used on the Great Lakes is presented for the layman. Illustrations of model utilization are presented and the complexities of ecosystem simulation are noted....

  2. Ecosystems in the Laboratory

    ERIC Educational Resources Information Center

    Madders, M.

    1975-01-01

    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)

  3. Ecosystem Management Strategies Katy Ransone

    E-print Network

    Dever, Jennifer A.

    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

  4. Allelopathy in Forested Ecosystems

    Microsoft Academic Search

    Azim U. Mallik

    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

  5. Exploring an Ecosystem

    NSDL National Science Digital Library

    National 4-H Council

    2009-01-01

    In this ecology activity, learners make a model water-based ecosystem called a terraqua column. The column (in a large soda bottle) includes pond water, duckweed, sand or gravel, and small snails. Learners observe what happens in their living model and consider such questions as what happens to animals and plants when humans harm an ecosystem. This activity is aligned to National Science Standards (NS.5-8.3 Life Science).

  6. Predicting effects of ecosystem engineering on species richness along primary productivity gradients

    Microsoft Academic Search

    Ernesto Iván Badano; Pablo Angel Marquet; Lohengrin Alexis Cavieres

    2010-01-01

    Physical ecosystem engineering is the process by which some species change the distribution of materials and energy in ecosystems. Although several studies have shown that this process is a driver of local species diversity, the current challenge is predicting when and where ecosystem engineering will have large or small impacts on communities, while also explaining why impacts vary in magnitude

  7. Pathways for School Finance in California. Technical Appendix

    ERIC Educational Resources Information Center

    Rose, Heather; Sonstelie, Jon; Weston, Margaret

    2010-01-01

    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…

  8. Assessing Educational Performance: California's School Quality Indicator System.

    ERIC Educational Resources Information Center

    Fetler, Mark

    The evolution of California's school accountability program, its current status, and some future directions are discussed. Public recognition of the need for school improvement resulted in California's Hughes Hart Education Reform Act (SB 813) of 1983, leading to the development of the California accountability program. Program components include:…

  9. Postharvest dried apricot color degradation of three California apricot accessions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    California’s dry apricot industry has provided high quality products for nearly a century, annually accounting for approximately 20% of available tonnage. The Patterson cultivar currently dominates California dry apricot sales, but the cultivar is not without faults. Newer cultivars and breeding a...

  10. Development of an Implementation Plan for Atmospheric Carbon Monitoring in California

    Microsoft Academic Search

    Marc L. Fischer; William J. Riley; Shaheen Tonse

    2004-01-01

    This report describes the design of atmospheric COâ concentration measurements that, in combination with other measurements and models, would be used to quantify regionally distributed COâ exchanges from California's terrestrial ecosystems and COâ emissions from fossil fuel combustion. Using models of net ecosystem COâ exchange (NEE), fossil fuel COâ emissions, and regional meteorology, we predict COâ concentration ''signals'' in the

  11. Application of non-market valuation to California's coastal policy decisions N. Raheem a,n

    E-print Network

    Vermont, University of

    Application of non-market valuation to California's coastal policy decisions N. Raheem a,n , S Available online 24 February 2012 Keywords: Non-market valuation Ecosystem services Economics a b s t r a c or the avoided cost method. Reported values of coastal ecosystems varied widely, and much of the valuation

  12. Organic matter sources and rehabilitation of the Sacramento-San Joaquin Delta (California, USA)

    E-print Network

    mosaic of tidal freshwater habitats in California. is the focus of a major ecosystem rehabilitation ma>- be sub-optimal at trophic levels supporting fish recruitment. A long historical data set is used-.and the implications of ecosystem rehabilitation actions for these sources. 2. Tributary-borne loading is the largest

  13. Nitrogen deposition in endemic-rich California serpentine grasslands Project details

    E-print Network

    Zavaleta, Erika

    Nitrogen deposition in endemic-rich California serpentine grasslands Project details 1. Historical reconstruction of anthropogenic N inputs into a Bay Area serpentine ecosystem using tree ring 15 N analysis High serpentine ecosystem with above-surface ammonium and nitrate collectors. We seek to quantify whether and how

  14. Ecological Signatures of Anthropogenically Altered Tidal Exchange in Estuarine Ecosystems

    Microsoft Academic Search

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

    2008-01-01

    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

  15. California Rocks!

    NSDL National Science Digital Library

    Mary Leech

    These course materials are for a basic college course in geology. Included are a course syllabus, websites of interest, the course project guidelines, and two field trip guides. Students can download a copy of the Periodic Table of the Elements and the Geologic Time Scale (detailed or simplified version). The main feature of the site is a series of slide shows for ten lectures covering basic geology with a focus on California. In addition there are lists of California's common rocks and minerals with photographs of each.

  16. Northern California

    NSDL National Science Digital Library

    The US Environmental Protection Agency presents this comprehensive dataset for northern California as part of a pilot study for its Environmental Monitoring and Assessment Program (EMAP). EMAP offers easy-to-use, GIS-based land use and environmental data designed to help resource managers better "understand and assess the status and trends in the condition of our ecological resources and the stressors affecting these systems." The northern California dataset includes detailed maps and information on hydrography, land cover, roads, vegetation, soils, land ownership, and so on -- all of which may be downloaded.

  17. Fog and Soil Weathering as Sources of Nutrients in a California Redwood Forest

    E-print Network

    Templer, Pamela

    function of many coastal ecosystems, including coast redwood forests. We examined cation and anion inputs, Weathers et al. 2000)--of many coastal forests, including coast redwood forests. Within California265 Fog and Soil Weathering as Sources of Nutrients in a California Redwood Forest Holly A. Ewing,1

  18. Estimating life-form cover fractions in California sage scrub communities using multispectral remote sensing

    Microsoft Academic Search

    Yuki Hamada; Douglas A. Stow; Dar A. Roberts

    The California sage scrub (CSS) community type in California's Mediterranean-type ecosystems is known for its high biodiversity and is home to a large number of rare, threatened, and endangered species. Because of extensive urban development in the past fifty years, this ecologically significant community type is highly degraded and fragmented. To conserve endangered CSS communities, monitoring internal conditions of communities

  19. Current titles

    SciTech Connect

    NONE

    1995-07-01

    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.

  20. Ecosystem growth and development.

    PubMed

    Fath, Brian D; Jørgensen, Sven E; Patten, Bernard C; Straskraba, Milan

    2004-11-01

    One of the most important features of biosystems is how they are able to maintain local order (low entropy) within their system boundaries. At the ecosystem scale, this organization can be observed in the thermodynamic parameters that describe it, such that these parameters can be used to track ecosystem growth and development during succession. Thermodynamically, ecosystem growth is the increase of energy throughflow and stored biomass, and ecosystem development is the internal reorganization of these energy mass stores, which affect transfers, transformations, and time lags within the system. Several proposed hypotheses describe thermodynamically the orientation or natural tendency that ecosystems follow during succession, and here, we consider five: minimize specific entropy production, maximize dissipation, maximize exergy storage (includes biomass and information), maximize energy throughflow, and maximize retention time. These thermodynamic orientors were previously all shown to occur to some degree during succession, and here we present a refinement by observing them during different stages of succession. We view ecosystem succession as a series of four growth and development stages: boundary, structural, network, and informational. We demonstrate how each of these ecological thermodynamic orientors behaves during the different growth and development stages, and show that while all apply during some stages only maximizing energy throughflow and maximizing exergy storage are applicable during all four stages. Therefore, we conclude that the movement away from thermodynamic equilibrium, and the subsequent increase in organization during ecosystem growth and development, is a result of system components and configurations that maximize the flux of useful energy and the amount of stored exergy. Empirical data and theoretical models support these conclusions. PMID:15527958

  1. California Solar Initiative California Public Utilities Commission

    E-print Network

    the market for solar energy by dramatically reducing the cost of solar. As part of the statewide solar effortCalifornia Solar Initiative California Public Utilities Commission Staff Progress Report January 2009 #12;2 California Solar Initiative CPUC Staff Progress Report - January 2009 The California Public

  2. Detritus fuels ecosystem metabolism but not metazoan food webs in San Francisco estuary's freshwater delta

    Microsoft Academic Search

    William V. Sobczak; James E. Cloern; Alan D. Jassby; Brian E. Cole; Tara S. Schraga; Andrew Arnsberg

    2005-01-01

    Detritus from terrestrial ecosystems is the major source of organic matter in many streams, rivers, and estuaries, yet the\\u000a role of detritus in supporting pelagic food webs is debated. We examined the importance of detritus to secondary productivity\\u000a in the Sacramento and San Joaquin River Delta (California, United States), a large complex of tidal freshwater habitats. The\\u000a Delta ecosystem has

  3. Constructing an Eocene Marine Ecosystem Sensitivity Scale

    NASA Astrophysics Data System (ADS)

    D'haenens, S.; Bornemann, A.; Speijer, R. P.; Hull, P. M.

    2014-12-01

    A key question in the face of current global environmental change is how marine ecosystems will respond and evolve in the future. To answer this, we first need to understand the relationship between environmental and ecosystem change - i.e., the ecosystem sensitivity. Addressing this question requires understanding of how biota respond to (a succession of) sudden environmental perturbations of varying sizes and durations in varying background conditions (i.e., climatic, oceanographic, biotic). Here, we compare new and published data from the Early to Middle Eocene greenhouse world to understand the sensitivity of marine ecosystems to background environmental change and hyperthermal events. This work focuses on the early Paleogene, because it is considered to be a good analog for a future high CO2 world. Newly generated high-resolution multiproxy datasets based on northern Atlantic DSDP Leg 48 and IODP Leg 342 material will allow us to compare the marine ecosystem responses (including bentho-pelagic systems) to abiotic drivers across climatic disruptions of differing magnitude. Initial results of a benthic foraminiferal community comparison including the PETM and ETM2 hyperthermals in the northeastern Atlantic DSDP sites 401 and 5501 suggest that benthic ecosystem sensitivity may actually be non-linearly linked to background climate states as reflected by a range of geochemical proxies (XRF, TOC, CaCO3, grain sizes, XRD clay mineralogy and foraminiferal ?18O, ?13C, Mg/Ca)2,3, in contrast to planktic communities4. Testing the type of scaling across different taxa, communities, initial background conditions and time scales may be the first big step to disentangle the often synergistic effects of environmental change on ecosystems5. References: 1D'haenens et al., 2012, in prep. 2Bornemann et al., 2014, EPSL 3D'haenens et al., 2014, PA 4Gibbs et al., 2012, Biogeosc. 5 Norris et al., 2013, Science

  4. Building sustainable ecosystem-oriented architectures

    E-print Network

    Bassil, Youssef

    2012-01-01

    Currently, organizations are transforming their business processes into e-services and service-oriented architectures to improve coordination across sales, marketing, and partner channels, to build flexible and scalable systems, and to reduce integration-related maintenance and development costs. However, this new paradigm is still fragile and lacks many features crucial for building sustainable and progressive computing infrastructures able to rapidly respond and adapt to the always-changing market and environmental business. This paper proposes a novel framework for building sustainable Ecosystem- Oriented Architectures (EOA) using e-service models. The backbone of this framework is an ecosystem layer comprising several computing units whose aim is to deliver universal interoperability, transparent communication, automated management, self-integration, self-adaptation, and security to all the interconnected services, components, and devices in the ecosystem. Overall, the proposed model seeks to deliver a co...

  5. Eruptive History and Chemical Evolution of the Precaldera and Postcaldera Basalt-Dacite Sequences, Long Valley, California: Implications for Magma Sources, Current Seismic Unrest, and Future Volcanism

    USGS Publications Warehouse

    Bailey, Roy A.

    2004-01-01

    The Long Valley Volcanic Field in east-central California straddles the East Sierran frontal fault zone, overlapping the Sierra Nevada and western Basin and Range Provinces. The volcanic field overlies a mature mid-Tertiary erosional surface that truncates a basement composed mainly of Mesozoic plutons and associated roof pendants of Mesozoic metavolcanic and Paleozoic metasedimentary rocks. Long Valley volcanism began about 4 Ma during Pliocene time and has continued intermittently through the Holocene. The volcanism is separable into two basalt-rhyolite episodes: (1) an earlier, precaldera episode related to Long Valley Caldera that climaxed with eruption of the Bishop Tuff and collapse of the caldera; and (2) a later, postcaldera episode structurally related to the north-south-trending Mono-Inyo Craters fissure system, which extends from the vicinity of Mammoth Mountain northward through the west moat of the caldera to Mono Lake. Eruption of the basalt-dacite sequence of the precaldera basalt-rhyolite episode peaked volumetrically between 3.8 and 2.5 Ma; few basalts were erupted during the following 1.8 m.y. (2.5?0.7 Ma). Volcanism during this interval was dominated by eruption of the voluminous rhyolites of Glass Mountain (2.2?0.8 Ma) and formation of the Bishop Tuff magma chamber. Catastrophic rupture of the roof of this magma chamber caused eruption of the Bishop Tuff and collapse of Long Valley Caldera (760 ka), after which rhyolite eruptions resumed on the subsided caldera floor. The earliest postcaldera rhyolite flows (700?500 ka) contain quenched globular basalt enclaves (mafic magmatic inclusions), indicating that basaltic magma had reentered shallow parts of the magmatic system after a 1.8-m.y. hiatus. Later, at about 400 ka, copious basalts, as well as dacites, began erupting from vents mainly in the west moat of the caldera. These later eruptions initiated the postcaldera basalt-rhyolite episode related to the Mono-Inyo Craters fissure system, which has been active through late Pleistocene and Holocene time.

  6. CALIFORNIA DAIRIES

    EPA Science Inventory

    These dairy records were collected by the California Department of Food and Agriculture (CDFA) as part of a trial for disease surveillance and prevention purposes. Some records contain GPS coordinates, while the remaining records were obtained through address matching methods u...

  7. California Dreaming

    ERIC Educational Resources Information Center

    Olson, Cathy Applefeld

    2011-01-01

    After getting her master's degree from UCLA, Nancy Wills dreamed of starting a school-based guitar program so she could teach students to make music on the instrument she'd loved since she was a kid growing up outside of Yosemite, California. She had a strong belief that guitar was perfect for schools, ideal for individualized playing but also…

  8. Radionuclide transport processes in terrestrial ecosystems

    SciTech Connect

    Whicker, F.W.

    1983-04-01

    Some major principles and the status of knowledge concerning the transport of radionuclides through terrestrial ecosystems are reviewed. Fundamental processes which control the flow of radionuclides between ecosystem components such as air, soil, plants, and animals are described, with emphasis on deposition, resuspension, plant uptake, ingestion, and assimilation. Properties of radionuclides, organisms, and ecosystems are examined in relation to their influence on the accumulation of radioactive materials by plants and animals. The effects of the physicochemical nature of the radionuclide; morphology, physiology, and behavior of the organism; and soil, nutrient, and trophic characteristics of the ecosystem are highlighted. Observations in natural ecosystems on radionuclides such as /sup 137/Cs, /sup 90/Sr, /sup 131/I, /sup 3/H, and /sup 239/Pu are used to illustrate current concepts. An assessment of the degree to which the processes controlling radionuclide behavior are understood and of our ability to simulate and predict such behavior with computerized models is offered. Finally, brief comments are made on research needs.

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

    NASA Astrophysics Data System (ADS)

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

    2012-12-01

    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.

  10. CALIFORNIA ENERGY COMMISSIONCOMMISSION

    E-print Network

    CALIFORNIA 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 and Questions W U· Wrap Up #12;THE CALIFORNIA CLEAN ENERGY JOBS ACTENERGY JOBS ACT · Combination of two recent

  11. Water quality in South San Francisco Bay, California: current condition and potential issues for the South Bay Salt Pond Restoration Project.

    PubMed

    Grenier, J Letitia; Davis, Jay A

    2010-01-01

    The SBSPRP is an extensive tidal wetland restoration project that is underway at the margin of South San Francisco Bay, California. The Project, which aims to restore former salt ponds to tidal marsh and manage other ponds for water bird support, is taking place in the context of a highly urbanized watershed and an Estuary already impacted by chemical contaminants. There is an intimate relationship between water quality in the watershed, the Bay, and the transitional wetland areas where the Project is located. The Project seeks to restore habitat for endangered and endemic species and to provide recreational opportunities for people. Therefore, water quality and bioaccumulation of contaminants in fish and wildlife is an important concern for the success of the Project. Mercury, PCBs, and PBDEs are the persistent contaminants of greatest concern in the region. All of these contaminants are present at elevated concentrations both in the abiotic environment and in wildlife. Dioxins, pyrethroids, PAHs, and selenium are also problematic. Organochlorine insecticides have historically impacted the Bay, and they remain above thresholds for concern in a small proportion of samples. Emerging contaminants, such as PFCs and non-PBDE flame retardants, are also an important water quality issue. Beyond chemical pollutants, other concerns for water quality in South San Francisco Bay exist, and include biological constituents, especially invasive species, and chemical attributes, such as dissolved oxygen and salinity. Future changes, both from within the Project and from the Bay and watershed, are likely to influence water quality in the region. Project actions to restore wetlands could worsen, improve, or not affect the already impaired water quality in South Bay. Accelerated erosion of buried sediment as a consequence of Project restoration actions is a potentially serious regional threat to South Bay water and sediment quality. Furthermore, the planned restoration of salt ponds to tidal marsh has raised concerns about possible increased net production of methylmercury and its subsequent accumulation in the food web. This concern applies not only to the restored marshes, but also to the South Bay as a whole, which could be affected on a regional scale. The ponds that are converted to tidal marsh will sequester millions of cubic meters of sediment. Sequestration of sediment in marshes could remove contaminated sediment from the active zone of the Bay but could also create marshes with contaminated food webs. Some of the ponds will not be restored to marsh but will be managed for use by water birds. Therefore, the effect of dense avian populations on eutrophication and the introduction of pathogens should be considered. Water quality in the Project also could be affected by external changes, such as human population growth and climate change. To address these many concerns related to water quality, the SBSPRP managers, and others faced with management of wetland restoration at a regional scale, should practice adaptive management and ongoing monitoring for water quality, particularly monitoring bioaccumulation of contaminants in the food web. PMID:20652671

  12. 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.

  13. Antarctic terrestrial ecosystems

    SciTech Connect

    Walton, D.W.H.

    1987-01-01

    The Maritime and Continental Antarctic terrestrial ecosystems are considered in the context of environmental impacts - habitat destruction, alien introductions, and pollution. Four types of pollution are considered: nutrients, radionuclides, inert materials, and noxious chemicals. Their ability to recover from perturbation is discussed in the light of present scientific knowledge, and the methods used to control impacts are reviewed. It is concluded that techniques of waste disposal are still inadequate, adequate training in environmental and conservation principles for Antarctic personnel in many countries is lacking, and scientific investigations may be a much more serious threat than tourism to the integrity of these ecosystems. Some priorities crucial to future management are suggested.

  14. Ecosystem approach: Healthy ecosystems and sustainable economies. Volume 3. Case studies. Final report

    SciTech Connect

    NONE

    1996-03-01

    The case study report of the Interagency Ecosystem Management Task Force presents findings and recommendations from seven survey teams, details the nature, history, and current status of each ecosystem, and summarizes survey team interviews with many participating parties. The volume targets those interested in how ecosystem partnerships work. Ecosystems include: Anacostia River watershed--state and local agencies are restoring components of this system of marshes, rivers, forests in urban environments: Coastal Louisiana--a federal task force and the state of Louisiana are restoring wetlands to reverse the trend of losses; Great Lakes basin--local communities joined with governmental agencies to reverse pollution and habitat degradation; Pacific Northwest forests--an interagency effort is protecting both forest ecosystems and the region`s economic health; Prince William Sound--a state/federal trustee council is restoring the ecosystem following the Exxon Valdez oil spill: South Florida--a federal task force is restoring habitat in the Everglades; and Southern Appalachians--the Man and Biosphere program is working with communities to restore habitats.

  15. [Advances in energy analysis of agro-ecosystems].

    PubMed

    Lu, Hongfang; Lan, Shengfang; Chen, Feipeng; Peng, Shaolin

    2004-01-01

    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

  16. Is Net Ecosystem Production Equal to Ecosystem Carbon Accumulation?

    E-print Network

    Berkowitz, Alan R.

    as ecosystem scientists investigate more fully the controls on the C balance of the biosphere. However of a complete organic C balance for an ecosystem, which can be written as: DCorg ¼ GPP þ I À Re À E À Oxnb ð1Þ In aquatic ecosystems, NEP is usually measured directly from the mass balance of oxygen (O2) or carbon

  17. Natural ecosystem design and control imperatives for sustainable ecosystem services

    Microsoft Academic Search

    Bernard C. Patten

    2010-01-01

    Sustainability of ecosystem services to humanity will depend on knowledge of how ecosystems work in their natural states, which can then be carried over to managed states. The objective of this paper is to describe four properties of ecosystems taken as natural conditions to be maintained under exploitation. Three of these are design properties: near-steady-state or extremal dynamics, dominance of

  18. 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

  19. 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...

  20. Energetics of an Aquatic Ecosystem

    NSDL National Science Digital Library

    William H. Leonard (University of Nebraska; )

    1982-06-21

    This activity is meant to give students an understanding of aquatic ecosystems and the processes and concepts that they are composed of and to give students a feel for how ecosystems affect the larger community.

  1. POEM: PESTICIDE ORCHARD ECOSYSTEM MODEL

    EPA Science Inventory

    The Pesticide Orchard Ecosystem Model (POEM) is a mathematical model of organophosphate pesticide movement in an apple orchard ecosystem. In addition submodels on invertebrate population dynamics are included. The fate model allows the user to select the pesticide, its applicatio...

  2. CALIFORNIA RCRA TSD FACILITY BOUNDARIES

    EPA Science Inventory

    Polygon coverage of RCRA TSD facility boundaries in California. These are derived from original maps and descriptions located in the US EPA Region 9 Records Center files. Current TSD facility designations were extracted from the ARIS (RCRIS) database in June 1998. Auxiliary tabl...

  3. CALIFORNIA RCRA TSD FACILITY LOCATIONS

    EPA Science Inventory

    Point coverage of RCRA TSD facility locations in California. These are derived from original maps and descriptions located in the US EPA Region 9 Records Center files. Current TSD facility designations were extracted from the ARIS (RCRIS) database in June 1998. Auxiliary tables ...

  4. The California School Psychologist, 2000.

    ERIC Educational Resources Information Center

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

    2000-01-01

    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;…

  5. The California School Psychologist, 2002.

    ERIC Educational Resources Information Center

    Jimerson, Shane R., Ed.

    2002-01-01

    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…

  6. Towards a standardized Rapid Ecosystem Function Assessment (REFA).

    PubMed

    Meyer, Sebastian T; Koch, Christiane; Weisser, Wolfgang W

    2015-07-01

    Quantifying ecosystem functioning is important for both fundamental and applied ecological research. However, there is currently a gap between the data available and the data needed to address topical questions, such as the drivers of functioning in different ecosystems under global change or the best management to sustain provisioning of ecosystem functions and services. Here, we identify a set of important functions and propose a Rapid Ecosystem Function Assessment (REFA). The proposed methods were specifically selected to be low-tech, easy to use, repeatable, and cost efficient. Thus, REFA enables standardized and comparable measurements of proxies for these functions that can be used at a large scale within and across studies. Adopting REFA can help to close the identified ecosystem functioning data gap. PMID:25997592

  7. Biocomplexity in mangrove ecosystems.

    PubMed

    Feller, I C; Lovelock, C E; Berger, U; McKee, K L; Joye, S B; Ball, M C

    2010-01-01

    Mangroves are an ecological assemblage of trees and shrubs adapted to grow in intertidal environments along tropical coasts. Despite repeated demonstration of their economic and societal value, more than 50% of the world's mangroves have been destroyed, 35% in the past two decades to aquaculture and coastal development, altered hydrology, sea-level rise, and nutrient overenrichment. Variations in the structure and function of mangrove ecosystems have generally been described solely on the basis of a hierarchical classification of the physical characteristics of the intertidal environment, including climate, geomorphology, topography, and hydrology. Here, we use the concept of emergent properties at multiple levels within a hierarchical framework to review how the interplay between specialized adaptations and extreme trait plasticity that characterizes mangroves and intertidal environments gives rise to the biocomplexity that distinguishes mangrove ecosystems. The traits that allow mangroves to tolerate variable salinity, flooding, and nutrient availability influence ecosystem processes and ultimately the services they provide. We conclude that an integrated research strategy using emergent properties in empirical and theoretical studies provides a holistic approach for understanding and managing mangrove ecosystems. PMID:21141670

  8. The Coral Reef Ecosystem

    NSDL National Science Digital Library

    2007-04-19

    Students examine a coral reef ecosystem to learn about its living and non-living parts and how they interact. They apply what they have learned to explore the world's biomes, including how the animals in each are adapted to their environment.

  9. 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...

  10. Case Study: Ecosystem Transformations

    E-print Network

    Nippert, Jesse

    142 Chapter 15 Case Study: Ecosystem Transformations Along The Colorado Front Range: Prairie Dog-tailed prairie dog. Directional changes in climate and atmospheric chemistry are altering the environment foothills and mixed-grass to short-grass prairie. Among these direc- tional changes are elevated average

  11. Boston Harbor Ecosystems

    NSDL National Science Digital Library

    This United States Geological Survey (USGS) site is designed to summarize and make available results of scientific research conducted in Boston Harbor, Massachusetts since 1985. A computer image of the harbor indicates ecosystem zones with descriptions (watershed, estuary, inner shelf, and basin), sewage outfall sites, and rock types. Links are provided for more information on this region.

  12. Shelf-sea ecosystems

    SciTech Connect

    Walsh, J J

    1980-01-01

    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.

  13. Role of the California Undercurrent in the export of denitrified waters from the eastern tropical North Pacific

    NASA Astrophysics Data System (ADS)

    Castro, C. G.; Chavez, F. P.; Collins, C. A.

    2001-12-01

    A transect off Point Sur, California (36°20'N), was occupied bimonthly from April 1988 to May 1990 to resolve spatial and temporal patterns in the physics and chemistry of the California Current system. Alongshore velocity fields and the chemical parameter N* [Gruber and Sarmiento, 1997] show coherence. Subarctic waters, conveyed by the California Current (CC), were characterized by high N* values, while in the region of poleward flow of the California Undercurrent (CU) a minimum of N* (N*< -5 ?mol kg-1) was observed. Low N* is a signature of denitrification, and its possible sources are considered. The distribution of N* on isopycnal surfaces, using data from the World Ocean Circulation Experiment Hydrographic Programme, suggests that northward advection from the eastern tropical North Pacific by the CU is the primary source of low N*. Local benthic and water column denitrification rates cannot account for the observed values. From nitrate deficits and velocity fields an annual nitrate transport deficit off Point Sur of 4.6 Tg N yr-1 was estimated for the study period. Maximum offshore extent of the low N* signal was observed during the upwelling period, probably associated with an expansion of the CU and mixing due to mesoscale eddies detached from it. This mixing propagates the denitrification signal into the CC and the subtropical gyre. When the loss from the poleward flow due to horizontal mixing is calculated, an export out of the eastern tropical North Pacific of 8.3 Tg N yr-1 by the CU is estimated. The bulk of the denitrified waters off Point Sur were below 400 m and did not affect primary production in the central California upwelling ecosystem. However, the export of nitrate-deficient waters into the subtropical gyre may play a role in the biogeochemical cycling of this region.

  14. 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.

  15. Pecos River Ecosystem Monitoring Project

    E-print Network

    McDonald, A.; Hart, C.

    2004-01-01

    TR- 272 2004 Pecos River Ecosystem Monitoring Project C. Hart A. McDonald Texas Water Resources Institute Texas A&M University - 146 - 2003 Pecos River Ecosystem Monitoring Project... Charles R. Hart, Extension Range Specialist, Fort Stockton Alyson McDonald, Extension Assistant – Hydrology, Fort Stockton SUMMARY The Pecos River Ecosystem Project is attempting to minimize the negative impacts of saltcedar on the river ecosystem...

  16. Seafloor off Natural Bridges State Beach, Santa Cruz, California

    USGS Publications Warehouse

    Storlazzi, Curt D.; Golden, Nadine E.; Gibbons, Helen

    2013-01-01

    The seafloor off Natural Bridges State Beach, Santa Cruz, California, is extremely varied, with sandy flats, boulder fields, faults, and complex bedrock ridges. These ridges support rich marine ecosystems; some of them form the "reefs" that produce world-class surf breaks. Colors indicate seafloor depth, from red-orange (about 2 meters or 7 feet) to magenta (25 meters or 82 feet).

  17. Modeling the Dynamic Water Resource Needs of California's Coastal Watersheds

    Microsoft Academic Search

    C. Alford

    2009-01-01

    Many watersheds face formidable water supply challenges when it comes to managing water availability to meet diverse water supply and ecosystem management objectives. California's central coast watersheds are no exception, and both the scarcity of water resources during drier water years and mandates to establish minimum instream flows for salmon habitat have prompted interests in reassessing water management strategies for

  18. Seafloor off Pleasure Point, Santa Cruz County, California

    USGS Publications Warehouse

    Storlazzi, Curt D.; Golden, Nadine E.; Gibbons, Helen

    2013-01-01

    The seafloor off Pleasure Point, Santa Cruz County, California, is extremely varied, with sandy flats, boulder fields, faults, and complex bedrock ridges. These ridges support rich marine ecosystems; some of them form the "reefs" that produce world-class surf breaks. Colors indicate seafloor depth, from red-orange (about 2 meters or 7 feet) to magenta (25 meters or 82 feet)

  19. Integrated Climate Change Impacts Assessment in California

    NASA Astrophysics Data System (ADS)

    Cayan, D. R.; Franco, G.; Meyer, R.; Anderson, M.; Bromirski, P. D.

    2014-12-01

    This paper summarizes lessons learned from an ongoing series of climate change assessments for California, conducted by the scientific community and State and local agencies. A series of three Assessments have considered vulnerability and adaptation issues for both managed and natural systems. California's vulnerability is many faceted, arising because of an exceptionally drought prone climate, open coast and large estuary exposure to sea level rise, sensitive ecosystems and complex human footprint and economy. Key elements of the assessments have been a common set of climate and sea-level rise scenarios, based upon IPCC GCM simulations. Regionalized and localized output from GCM projections was provided to research teams investigating water supply, agriculture, coastal resources, ecosystem services, forestry, public health, and energy demand and hydropower generation. The assessment results are helping to investigate the broad range of uncertainty that is inherent in climate projections, and users are becoming better equipped to process an envelope of potential climate and impacts. Some projections suggest that without changes in California's present fresh-water delivery system, serious water shortages would take place, but that technical solutions are possible. Under a warmer climate, wildfire vulnerability is heightened markedly in some areas--estimated increases in burned area by the end of the 21st Century exceed 100% of the historical area burned in much of the forested areas of Northern California Along California coast and estuaries, projected rise in mean sea level will accelerate flooding occurrences, prompting the need for better education and preparedness. Many policymakers and agency personnel in California are factoring in results from the assessments and recognize the need for a sustained assessment process. An ongoing challenge, of course, is to achieve more engagement with a broader community of decision makers, and notably with the private sector.

  20. Ecosystem Task Force Meeting Minutes

    E-print Network

    New Hampshire, University of

    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

  1. Investigating Ecosystems in a Biobottle

    ERIC Educational Resources Information Center

    Breene, Arnica; Gilewski, Donna

    2008-01-01

    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…

  2. Scientific Foundations for an IUCN Red List of Ecosystems

    PubMed Central

    Keith, David A.; Rodríguez, Jon Paul; Rodríguez-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; Comín, 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, María A.; Pisanu, Phil; Poulin, Brigitte; Regan, Tracey J.; Riecken, Uwe; Spalding, Mark D.; Zambrano-Martínez, Sergio

    2013-01-01

    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 world’s ecosystems. This will complement the Red List of species and strengthen global capacity to report on and monitor the status of biodiversity PMID:23667454

  3. Modeling forest fire severity in California, USA

    NASA Astrophysics Data System (ADS)

    Keyser, A.; Westerling, A. L.

    2009-12-01

    A long history of fire suppression in the western United States has interrupted the fire regimes of many forest types. This interruption has significantly changed forest structure and ecological function and led to increasingly uncharacteristic fires in terms of size and severity. Identifying areas at risk for fires whose severity is outside the natural fire regime will allow for targeted fuel reduction and mitigation to preserve ecosystem integrity. The probability of large fire occurrence has been successfully predicted and forecast using hydro-climate variables and statistical modeling techniques. We are employing similar statistical techniques to test the potential for predicting and forecasting forest fire severity for California, USA under current and future climate scenarios. We have a mapped fire severity dataset for forest fires spanning twenty-two years (1984-2006) for California as well as a suite of topographic and vegetation data layers from the Landfire project. Our hydro-climate dataset was developed using the VIC hydrologic model with the LDAS parameterization; we thus used the LDAS 1/8° grid to sample our fire severity, topographic and vegetation datasets. Initial exploratory analyses of the hydro-climate data show that low fractional fire severity is positively correlated to cumulative precipitation for the 12-month prior period and the 12-month period ending 6-month prior to the month of the fire, while moderate to high fractional severity is negatively correlated. Relationships opposite in sign, but comparative in magnitude, were found for cumulative adjusted moisture deficit for 12 months prior to the month of fire and the 12-month period ending 6 months prior to the fire. Additionally, fire area was positively correlated to both cumulative moisture deficit variables. Current year March and April snow water equivalent were negatively correlated to moderate and high fractional fire severity. Using only hydro-climate data predictors, we were able to predict high severity fraction (fraction of the fire in the high severity category relative to fire size) using a third order polynomial regression with the following independent variables: one year moisture deficit, average relative humidity, monthly average temperature, mean elevation, the latter three for month of fire. These relationships are expected as we know that fuel moisture is an important control on potential fire severity and all will affect fuel moisture content. We also know that vegetation, fuels, and topography affect potential fire severity. We will add these data layers to the aforementioned hydro-climate variables to improve our predictive capability. A refined prediction model will be presented with forecast of potential changes in fire severity under climate change scenarios.

  4. Assessing Climate Change Impacts on Vernal Pool Ecosystems and Endemic Branchiopods

    Microsoft Academic Search

    Christopher R. Pyke

    2005-01-01

    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

  5. Global Educational Ecosystem: Case Study of a Partnership with K-12 Schools, Community Organizations, and Business

    ERIC Educational Resources Information Center

    Lewis, Donna S.

    2010-01-01

    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…

  6. 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 ...

  7. Sound management may sequester methane in grazed rangeland ecosystems

    PubMed Central

    Wang, Chengjie; Han, Guodong; Wang, Shiping; Zhai, Xiajie; Brown, Joel; Havstad, Kris M.; Ma, Xiuzhi; Wilkes, Andreas; Zhao, Mengli; Tang, Shiming; Zhou, Pei; Jiang, Yuanyuan; Lu, Tingting; Wang, Zhongwu; Li, Zhiguo

    2014-01-01

    Considering their contribution to global warming, the sources and sinks of methane (CH4) should be accounted when undertaking a greenhouse gas inventory for grazed rangeland ecosystems. The aim of this study was to evaluate the mitigation potential of current ecological management programs implemented in the main rangeland regions of China. The influences of rangeland improvement, utilization and livestock production on CH4 flux/emission were assessed to estimate CH4 reduction potential. Results indicate that the grazed rangeland ecosystem is currently a net source of atmospheric CH4. However, there is potential to convert the ecosystem to a net sink by improving management practices. Previous assessments of capacity for CH4 uptake in grazed rangeland ecosystems have not considered improved livestock management practices and thus underestimated potential for CH4 uptake. Optimal fertilization, rest and light grazing, and intensification of livestock management contribute mitigation potential significantly. PMID:24658176

  8. Assimilation of satellite color observations in a coupled ocean GCM-ecosystem model

    NASA Technical Reports Server (NTRS)

    Sarmiento, Jorge L.

    1992-01-01

    Monthly average coastal zone color scanner (CZCS) estimates of chlorophyll concentration were assimilated into an ocean global circulation model(GCM) containing a simple model of the pelagic ecosystem. The assimilation was performed in the simplest possible manner, to allow the assessment of whether there were major problems with the ecosystem model or with the assimilation procedure. The current ecosystem model performed well in some regions, but failed in others to assimilate chlorophyll estimates without disrupting important ecosystem properties. This experiment gave insight into those properties of the ecosystem model that must be changed to allow data assimilation to be generally successful, while raising other important issues about the assimilation procedure.

  9. Building an Ecosystem

    NSDL National Science Digital Library

    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

    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.

  10. The use of stable isotopes to study ecosystem gas exchange

    Microsoft Academic Search

    D. Yakir; L. da S. L. Sternberg

    2000-01-01

    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

  11. Primary production: Terrestrial ecosystems

    Microsoft Academic Search

    Helmut Lieth

    1973-01-01

    The history of growth in understanding of primary productivity and in making estimates of biosphere production is reviewed. Two approaches to estimation of land production are discussed. Production may first be estimated by mean values for ecosystem types and the areas of these. A total production of 100×10\\u000a9 tons\\/year is thus estimated for the continents, making up 29% of

  12. Relighting Forest Ecosystems

    Microsoft Academic Search

    Jay E. Steele; Robert Geist

    2009-01-01

    Real-time cinematic relighting of large, forest ecosystems remains a challenging problem, in that important global illumination\\u000a effects, such as leaf transparency and inter-object light scattering, are difficult to capture, given tight timing constraints\\u000a and scenes that typically contain hundreds of millions of primitives. A solution that is based on a lattice-Boltzmann method\\u000a is suggested. Reflectance, transmittance, and absorptance parameters are

  13. 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.

  14. University of California Digital Map Collection

    NSDL National Science Digital Library

    Since the Scout Report last visited the Digital Map Collection at the University of California, there have been many worthy additions to this cartographic cornucopia. The maps are both historic and contemporary, and they include zoning maps, land use maps, historic maps of the state's coastline, and so on. Visitors can elect to browse all of the California digital maps, or the non-California digital maps here. Currently, there are over 475 California maps, and visitors can browse the offerings by call number title, keyword, title, and more. On the non-California side of things, there are over 10,000 maps, and they deal with just about every topic under the geographical sun. The site is rounded out by a list of digital topographic map sets, and a link to a more specialized search engine for the maps.

  15. Louisiana Coastal Ecosystem

    USGS Publications Warehouse

    U.S. Geological Survey

    2000-01-01

    Louisiana's coast and its degradation and restoration are major environmental issues being studied at the National Wetlands Research Center. Coastal ecosystems are vulnerable because of the tremendous amount of human activity that takes place along the coast. Information on ecological processes is essential to guide the development along the coast as well as to protect and restore wildlife habitat. Louisiana has about 40% of coastal wetlands in the lower 48 states; they support fish, waterfowl, and fur-bearing animals as well as unique cultures like that of the Acadians. The fish and wildlife resources of Louisiana's coast produce over $1 billion each year in revenues. But Louisiana has the highest coastal loss rate because of natural and human causes. Over the past three decades, Louisiana has lost as much as 35-40 mi2 (90-104 km2) of coastal wetlands a year. The National Wetlands Research Center is qualified to assess and monitor this ecosystem because of its proximity to the study area, a staff chosen for their expertise in the system, and a number of established partnerships with others who study the areas. The Center is often the lead group in partnerships with universities, other federal agencies, and private entities who study this ecosystem. Most of the Center's research and technology development performed for coastal wetlands are done at the Lafayette headquarters; some work is performed at the National Wetlands Research Center's project office in Baton Rouge, LA.

  16. 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

  17. CALIFORNIA STATEWIDE RESIDENTIAL APPLIANCE

    E-print Network

    &E) Southern California Edison (SCE) Southern California Gas Company (SoCalGas) Los Angeles Department of Water or the State of California. The Energy Commission, the State of California, its employees, contractors....................................................................... 48 2.5.3 Energy Usage Comparison

  18. Assessment of Potential Aquatic Herbicide Impacts to California Aquatic Ecosystems

    E-print Network

    . Results therefore warrant full risk characterization for all adjuvant compounds. Introduction Many organic to determine potential impacts. For sediment-partitioning herbicides, sediment quality triad analysis as Roundup, contains nonylphenol ethoxylate (NPE) surfactants that are toxic to aquatic organisms, whereas

  19. Historical Jigsaw Puzzles: Piecing Together the Understory of Garry Oak (Quercus garryana) Ecosystems and the Implications for Restoration1

    Microsoft Academic Search

    Carrina Maslovat

    Ecosystem restoration requires a set of reference vegetation conditions which are difficult to find for Garry oak (Quercus garryana) ecosystems in Canada because contemporary sites have been drastically altered. A survey of historical information provides only limited clues about the original understory vegetation. Although there is considerable variation in the soils, climate, and successional status of current ecosystems, an exploration

  20. SPATIAL REPRESENTATION AND SPECIFICATION OF ECOSYSTEM SERVICES: A METHODOLOGY USING LAND USE\\/LAND COVER DATA AND STAKEHOLDER ENGAGEMENT

    Microsoft Academic Search

    W. R. SHEATE; R. P. EALES; E. DALY; J. BAKER; A. MURDOCH; C. HILL; U. OJIKE; T. KARPOUZOGLOU

    2012-01-01

    The challenge for implementing an ecosystems approach to environmental decision-making processes, such as spatial planning, is to understand the range, nature and amount of ecosystem services currently provided and the potential for such service provision in the future. The ability to spatially represent ecosystems services is a critical element of the evidence base on which to make decisions about how

  1. Ecosystem approaches to human health.

    PubMed

    Nielsen, N O

    2001-01-01

    The promotion of human health must be embedded in the wider pursuit of ecosystem health. Interventions will be impaired if ecosystem-linked determinants of health are not taken into account. In the extreme case, if ecosystems lose their capacity for renewal, society will lose life support services. Essential features of ecosystem health are the capacity to maintain integrity and to achieve reasonable and sustainable human goals. An ecosystem approach to research and management must be transdisciplinary and assure participation of stakeholders. These requisites provide a means for science to better deal with the complexity of ecosystems, and for policy-makers and managers to establish and achieve reasonable societal goals. The ecosystem approach can determine links between human health and activities or events which disturb ecosystem state and function. Examples are: landscape disturbance in agriculture, mining, forestry, urbanization, and natural disasters. An understanding of these links can provide guidance for management interventions and policy options that promote human health. An ecosystem approach to management must be adaptive because of irreducible uncertainty in ecosystem function. PMID:11426267

  2. Good Ecosystem Governance: Balancing Ecosystems and Social Needs

    Microsoft Academic Search

    Malin Falkenmark

    The overarching problem behind the need for good ecosystem governance is the fact that human needs for water, food, energy,\\u000a etc., generally demand manipulations of landscape components. Due to water’s role as the bloodstream of the biosphere, with\\u000a many parallel functions in the landscape, and ecosystems’ water-dependence, ecosystems tend to get impacted by those manipulations.\\u000a Societal activities that have to

  3. Carbon cycling in high-latitude ecosystems

    NASA Technical Reports Server (NTRS)

    Townsend, Alan; Frolking, Stephen; Holland, Elizabeth

    1992-01-01

    The carbon-rich soils and peatlands of high-latitude ecosystems could substantially influence atmospheric concentrations of CO2 and CH4 in a changing climate. Currently, cold, often waterlogged conditions retard decomposition, and release of carbon back to the atmosphere may be further slowed by physical protection of organic matter in permafrost. As a result, many northern ecosystems accumulate carbon over time (Billings et al., 1982; Poole and Miller, 1982), and although such rates of accumulation are low, thousands of years of development have left Arctic ecosystems with an extremely high soil carbon content; Schlesinger's (1984) average value of 20.4 kg C/m(sup 2) leads to a global estimate of 163 x 10(exp 15) g C. All GCM simulations of a doubled CO2 climate predict the greatest warming to occur in the polar regions (Dickinson, 1986; Mitchell, 1989). Given the extensive northern carbon pools and the strong sensitivity of decomposition processes to temperature, even a slight warming of the soil could dramatically alter the carbon balance of Arctic ecosystems. If warming accelerates rates of decomposition more than rates of primary production, a sizeable additional accumulation of CO2 in the atmosphere could occur. Furthermore, CH4 produced in anaerobic soils and peatlands of the Arctic already composes a good percentage of the global efflux (Cicerone and Oremlund, 1988); if northern soils become warmer and wetter as a whole, CH4 emissions could dramatically rise. A robust understanding of the primary controls of carbon fluxes in Arctic ecosystems is critical. As a framework for a systematic examination of these controls, we discussed a conceptual model of regional-scale Arctic carbon turnover, including CH4 production, and based upon the Century soil organic matter model.

  4. The Niger Delta wetlands: threats to ecosystem services, their importance to dependent communities and possible management measures

    Microsoft Academic Search

    Olalekan Adekola; Gordon Mitchell

    2011-01-01

    The Niger Delta wetlands are changing rapidly, raising concern for the wetlands' health and for communities relying upon its ecosystem services. Knowledge on ecosystem service provision is important for effective ecosystem and livelihoods management, but is currently lacking for the Niger Delta. We synthesised literature and used the ‘Drivers–pressure–state–impact–response’ (DPSIR) framework to structure information on changes in the wetlands' ecosystem

  5. Great Lakes rivermouth ecosystems: scientific synthesis and management implications

    USGS Publications Warehouse

    Larson, James H.; Trebitz, Anett S.; Steinman, Alan D.; Wiley, Michael J.; Carlson Mazur, Martha; Pebbles, Victoria; Braun, Heather A.; Seelbach, Paul W.

    2013-01-01

    At the interface of the Great Lakes and their tributary rivers lies the rivermouths, a class of aquatic ecosystem where lake and lotic processes mix and distinct features emerge. Many rivermouths are the focal point of both human interaction with the Great Lakes and human impacts to the lakes; many cities, ports, and beaches are located in rivermouth ecosystems, and these human pressures often degrade key ecological functions that rivermouths provide. Despite their ecological uniqueness and apparent economic importance, there has been relatively little research on these ecosystems as a class relative to studies on upstream rivers or the open-lake waters. Here we present a synthesis of current knowledge about ecosystem structure and function in Great Lakes rivermouths based on studies in both Laurentian rivermouths, coastal wetlands, and marine estuarine systems. A conceptual model is presented that establishes a common semantic framework for discussing the characteristic spatial features of rivermouths. This model then is used to conceptually link ecosystem structure and function to ecological services provided by rivermouths. This synthesis helps identify the critical gaps in understanding rivermouth ecology. Specifically, additional information is needed on how rivermouths collectively influence the Great Lakes ecosystem, how human alterations influence rivermouth functions, and how ecosystem services provided by rivermouths can be managed to benefit the surrounding socioeconomic networks.

  6. Assessing risks to ecosystem quality

    SciTech Connect

    Barnthouse, L.W. [Oak Ridge National Lab., TN (United States)

    1995-12-31

    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.

  7. 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.

  8. Integrated Science Investigations of the Salton Sea, California, USA

    NASA Astrophysics Data System (ADS)

    Barnum, D.

    2006-12-01

    The Salton Sea is the latest waterbody to be formed by Colorado River floodwaters within the Salton Trough. Over the past 100 years, floodwaters have been replaced by agricultural drainage water and municipal discharges so that today, most of the water reaching the Salton Sea is agricultural drainwater flowing down the New, Alamo and Whitewater Rivers. An evaporation of about 6 feet per year and inputs of more than 4 million tons of salt per year have increased salinity of the waters of the Salton Sea. The current salinity level of approximately 46 parts per thousand is about 25% more saline than ocean water. Diverting water from the Imperial Valley agricultural lands to urban Southern California, and anticipated loss of inflows from Mexico and increasing water conservation activities will result in less water flowing into the Salton Sea. A Restoration Program is being conducted to evaluate the effects of diminished inflows on the Salton Sea Ecosystem and recommend alternatives to avoid or minimize those effects. The Salton Sea has become increasingly important as habitat for migratory birds because of wetland losses. California has lost approximately 91% of interior wetland acreage from pre-settlement until the mid-1980's. The Salton Sea provides critical habitat linking distant wetlands of Pacific and Central Flyways to wintering habitats in Mexico and Central and South America. More than 400 species of birds have been observed in the Salton Sea Ecosystem. Large percentages of the populations for several bird species such as the endangered Yuma Clapper Rail, the Eared Grebe, Snowy Plover and American White Pelican utilize the Salton Sea. Approximately 20 species of conservation concern utilize the Salton Sea ecosystem. Fish-eating birds such as Great Blue Herons, California Brown Pelicans, Double-crested Cormorants and several species of egrets are highly dependent upon the fishery of the Salton Sea. The Salton Sea fishery is now primarily comprised of tilapia. However, as recently as 2001 the fishery was comprised of tilapia and 3 species of salt water fish, and was described as one of the most productive fisheries in the world. The loss of the fishery has significant consequences for the fish-eating birds and a productive sport fishing industry. Arresting salinity as a means for sustaining the fishery of the Salton Sea is a major focus for the Salton Sea Restoration Project. Other issues affecting restoration include selenium, hydrogen sulfide generating sediments, air quality issues associated with the amount of the current Salton Sea that will become dry, loss of migratory bird habitat as the lake level recedes, and loss of invertebrate communities. The USGS Salton Sea Science Office is working with state, local and tribal governments, academic institutions, and other federal agencies to develop integrated plans for evaluating nutrient dynamics, contaminants for migratory birds and human health, evaluations of various restoration alternatives, avian population dynamics, air quality related studies including sediment characterization of the Salton Sea lake bed and emissions data analysis, larval fish abundance and distribution data analysis, salinity tolerance limits for fish, and wetland habitat restoration.

  9. Pteropods in Southern Ocean ecosystems

    NASA Astrophysics Data System (ADS)

    Hunt, B. P. V.; Pakhomov, E. A.; Hosie, G. W.; Siegel, V.; Ward, P.; Bernard, K.

    2008-09-01

    To date, little research has been carried out on pelagic gastropod molluscs (pteropods) in Southern Ocean ecosystems. However, recent predictions are that, due to acidification resulting from a business as usual approach to CO 2 emissions (IS92a), Southern Ocean surface waters may begin to become uninhabitable for aragonite shelled thecosome pteropods by 2050. To gain insight into the potential impact that this would have on Southern Ocean ecosystems, we have here synthesized available data on pteropod distributions and densities, assessed current knowledge of pteropod ecology, and highlighted knowledge gaps and directions for future research on this zooplankton group. Six species of pteropod are typical of the Southern Ocean south of the Sub-Tropical Convergence, including the four Thecosomes Limacina helicina antarctica, Limacina retroversa australis, Clio pyramidata, and Clio piatkowskii, and two Gymnosomes Clione limacina antarctica and Spongiobranchaea australis. Limacina retroversa australis dominated pteropod densities north of the Polar Front (PF), averaging 60 ind m -3 (max = 800 ind m -3) and 11% of total zooplankton at the Prince Edward Islands. South of the PF L. helicina antarctica predominated, averaging 165 ind m -3 (max = 2681 ind m -3) and up to >35% of total zooplankton at South Georgia, and up to 1397 ind m -3 and 63% of total zooplankton in the Ross Sea. Combined pteropods contributed <5% to total zooplankton in the Lazarev Sea, but 15% (max = 93%) to macrozooplankton in the East Antarctic. In addition to regional density distributions we have synthesized data on vertical distributions, seasonal cycles, and inter-annual density variation. Trophically, gymnosome are specialist predators on thecosomes, while thecosomes are considered predominantly herbivorous, capturing food with a mucous web. The ingestion rates of L. retroversa australis are in the upper range for sub-Antarctic mesozooplankton (31.2-4196.9 ng pig ind -1 d -1), while those of L. helicina antarctica and C. pyramidata are in the upper range for all Southern Ocean zooplankton, in the latter species reaching 27,757 ng pig ind -1 d -1 and >40% of community grazing impact. Further research is required to quantify diet selectivity, the effect of phytoplankton composition on growth and reproductive success, and the role of carnivory in thecosomes. Life histories are a significant knowledge gap for Southern Ocean pteropods, a single study having been completed for L. retroversa australis, making population studies a priority for this group. Pteropods appear to be important in biogeochemical cycling, thecosome shells contributing >50% to carbonate flux in the deep ocean south of the PF. Pteropods may also contribute significantly to organic carbon flux through the production of fast sinking faecal pellets and mucous flocs, and rapid sinking of dead animals ballasted by their aragonite shells. Quantification of these contributions requires data on mucous web production rates, egestion rates, assimilation efficiencies, metabolic rates, and faecal pellet morphology for application to sediment trap studies. Based on the available data, pteropods are regionally significant components of the Southern Ocean pelagic ecosystem. However, there is an urgent need for focused research on this group in order to quantify how a decline in pteropod densities may impact on Southern Ocean ecosystems.

  10. Structural and Functional Loss in Restored Wetland Ecosystems

    PubMed Central

    Moreno-Mateos, David; Power, Mary E.; Comín, Francisco A.; Yockteng, Roxana

    2012-01-01

    Wetlands are among the most productive and economically valuable ecosystems in the world. However, because of human activities, over half of the wetland ecosystems existing in North America, Europe, Australia, and China in the early 20th century have been lost. Ecological restoration to recover critical ecosystem services has been widely attempted, but the degree of actual recovery of ecosystem functioning and structure from these efforts remains uncertain. Our results from a meta-analysis of 621 wetland sites from throughout the world show that even a century after restoration efforts, biological structure (driven mostly by plant assemblages), and biogeochemical functioning (driven primarily by the storage of carbon in wetland soils), remained on average 26% and 23% lower, respectively, than in reference sites. Either recovery has been very slow, or postdisturbance systems have moved towards alternative states that differ from reference conditions. We also found significant effects of environmental settings on the rate and degree of recovery. Large wetland areas (>100 ha) and wetlands restored in warm (temperate and tropical) climates recovered more rapidly than smaller wetlands and wetlands restored in cold climates. Also, wetlands experiencing more (riverine and tidal) hydrologic exchange recovered more rapidly than depressional wetlands. Restoration performance is limited: current restoration practice fails to recover original levels of wetland ecosystem functions, even after many decades. If restoration as currently practiced is used to justify further degradation, global loss of wetland ecosystem function and structure will spread. PMID:22291572

  11. Statistical dynamic modeling on ecosystem patterns

    Microsoft Academic Search

    Yi Chen; Li He Chai; Xin Zhang

    2010-01-01

    Ecosystems are typical complex adaptive systems. By a universal principle (MFP) on pattern formation of ecosystems, the underlying microscopic dynamic mechanisms that induce complex patterns in ecosystems can be revealed. The ecosystem patterns are further simulated by invoking theoretical model of artificial neural network of Self-Organization Feature Map (SOM), by which evolution processes, structural classifications and fractal growth of ecosystem

  12. Essays on the California Drought

    E-print Network

    Luoma, Samuel N.

    2014-01-01

    JUNE 2014 Essays on the California Drought Samuel N. Luoma*1 University of California Drought Summit, California Statedrought, human and ecological demands for water are not aligned with supplies in California.

  13. POLLUTION AND ECOSYSTEM HEALTH - ASSESSING ECOLOGICAL CONDITION OF COASTAL ECOSYSTEMS

    EPA Science Inventory

    Summers, Kevin. 2004. Pollution and Ecosystem Health - Assessing Ecological Condition of Coastal Ecosystems. Presented at the White Water to Blue Water (WW2BW) Miami Conference, 21-26 March 2004, Miami, FL. 1 p. (ERL,GB R973). Throughout the coastal regions and Large Mari...

  14. Science for managing ecosystem services: Beyond the Millennium Ecosystem Assessment

    Microsoft Academic Search

    Stephen R. Carpenter; Harold A. Mooney; John Agard; Doris Capistrano; Ruth S. Defries; Sandra Díaz; Thomas Dietz; Anantha K. Duraiappah; Alfred Oteng-Yeboah; Henrique Miguel Pereira; Charles Perrings; Walter V. Reid; José Sarukhan; Robert J. Scholes; Anne Whyte

    2009-01-01

    The Millennium Ecosystem Assessment (MA) introduced a new framework for analyzing social-ecological systems that has had wide influence in the policy and scientific communities. Studies after the MA are taking up new challenges in the basic science needed to assess, project, and manage flows of ecosystem services and effects on human well-being. Yet, our ability to draw general conclusions remains

  15. Nitrogen in aquatic ecosystems.

    PubMed

    Rabalais, Nancy N

    2002-03-01

    Aquatic ecosystems respond variably to nutrient enrichment and altered nutrient ratios, along a continuum from fresh water through estuarine, coastal, and marine systems. Although phosphorus is considered the limiting nutrient for phytoplankton production in freshwater systems, the effects of atmospheric nitrogen and its contribution to acidification of fresh waters can be detrimental. Within the estuarine to coastal continuum, multiple nutrient limitations occur among nitrogen, phosphorus, and silicon along the salinity gradient and by season, but nitrogen is generally considered the primary limiting nutrient for phytoplankton biomass accumulation. There are well-established, but nonlinear, positive relationships among nitrogen and phosphorus flux, phytoplankton primary production, and fisheries yield. There are thresholds, however, where the load of nutrients to estuarine, coastal and marine systems exceeds the capacity for assimilation of nutrient-enhanced production, and water-quality degradation occurs. Impacts can include noxious and toxic algal blooms, increased turbidity with a subsequent loss of submerged aquatic vegetation, oxygen deficiency, disruption of ecosystem functioning, loss of habitat, loss of biodiversity, shifts in food webs, and loss of harvestable fisheries. PMID:12077998

  16. Long term (>100 years) Carbon Sequestration in California Coastal Salt Marshes

    NASA Astrophysics Data System (ADS)

    Brown, L. N.; MacDonald, G. M.; Holmquist, J. R.

    2014-12-01

    Coastal salt marsh ecosystems rank as one of the ecosystems which sequester the most carbon (C) in the world (Chmura, 2003; Mcleod et al., 2011). California hosts multiple small marsh ecosystems outside of the San Francisco Bay that are limited in geographic extent but still contribute significantly to global soil C. This study evaluates 11 marsh sites along the California coast for annual soil C sequestration rates using 14C, 137Cs, and 210Pb chronologies. Estimates of carbon sequestration for California over the past 100 years from this study average at 49 g C m-2 yr-1. Long term estimates of soil C generally are lower because of natural decomposition of organic C, but this study indicates a persistence of high C storage capacity for coastal marsh systems. These estimates provide valuable insight into the long term capacity for coastal salt marshes to mitigate climate change through sequestration of C.

  17. Prototyping an online wetland ecosystem services model using open model sharing standards

    Microsoft Academic Search

    Min Feng; Shuguang Liu; Ned H. Euliss Jr.; Claudia Young; David M. Mushet

    2011-01-01

    Great interest currently exists for developing ecosystem models to forecast how ecosystem services may change under alternative land use and climate futures. Ecosystem services are diverse and include supporting services or functions (e.g., primary production, nutrient cycling), provisioning services (e.g., wildlife, groundwater), regulating services (e.g., water purification, floodwater retention), and even cultural services (e.g., ecotourism, cultural heritage). Hence, the knowledge

  18. Is ecosystem structure the target of concern in ecological effect assessments?

    PubMed

    De Laender, Frederik; De Schamphelaere, Karel A C; Vanrolleghem, Peter A; Janssen, Colin R

    2008-05-01

    The species sensitivity distribution, a technique currently used to derive water-quality standards of chemicals, is associated with a set of inadequately tested assumptions. One of these assumptions is that ecosystem structure is as or more sensitive than ecosystem function, i.e., that structure is the target of concern. In this paper, we tested this assumption for a simple freshwater ecosystem exposed to different toxicants. Using an ecosystem model, we calculated no observed effect concentrations (NOECs) for ecosystem structure (ecosystem structure-NOECs) and function (ecosystem function-NOECs) for each of 1000 hypothetical toxicants. For 979 of these toxicants, the ecosystem structure-NOEC was lower than or equal to the ecosystem function-NOEC, indicating that the tested assumption can be considered valid. For 239 of these 979 toxicants, both NOECs were equal. For half of the 1000 toxicants, the structure of lower trophic levels (i.e., phytoplankton) appears to be more sensitive than the structure of higher trophic levels (i.e., fish). As such, ecosystem structure-NOECs are primarily determined by the sensitivity of the structure of lower trophic levels. In contrast, ecosystem functions associated with higher trophic levels (e.g., total ingestion by fish) are more sensitive than functions associated with lower trophic levels (e.g., total photosynthesis by phytoplankton) for 749 toxicants. PMID:18258280

  19. Long-term variation in a central California pelagic forage assemblage

    NASA Astrophysics Data System (ADS)

    Ralston, Stephen; Field, John C.; Sakuma, Keith M.

    2015-06-01

    A continuous 23 year midwater trawl survey (1990-2012) of the epipelagic forage assemblage off the coast of central California (lat. 36°30?-38°20? N) is described and analyzed. Twenty taxa occurred in ? 10% of the 2037 trawls that were completed at 40 distinct station locations. The dominant taxa sampled by the 9.5 mm mesh net included a suite of young-of-the-year (YOY) groundfish, including rockfish (Sebastes spp.) and Pacific hake (Merluccius productus), two clupeoids (Engraulis mordax and Sardinops sagax), krill (Euphausiacea), cephalopods (Doryteuthis opalescens and Octopus sp.), and a variety of mesopelagic species, i.e., Diaphus theta, Tarltonbeania crenularis, "other" lanternfish (Myctophidae), deep-sea smelts (Bathylagidae), and sergestid shrimp. Annual abundance estimates of the 20 taxa were obtained from analysis of variance models, which included year and station as main effects. Principal components analysis of the abundance estimates revealed that 61% of assemblage variance was explained by the first three components. The first component revealed a strong contrast in the abundance of: (a) YOY groundfish, market squid (D. opalescens), and krill with (b) mesopelagics and clupeoids; the second component was associated with long-term trends in abundance. An evaluation of 10 different published oceanographic data sets and CTD data collected during the survey indicated that seawater properties encountered each year were significantly correlated with abundance patterns, as were annual sea-level anomalies obtained from an analysis of AVISO satellite information. A comparison of our findings with several other recent studies of biological communities occurring in the California Current revealed a consistent structuring of forage assemblages, which we conjecture is primarily attributable to large-scale advection patterns in the California Current ecosystem.

  20. Local extirpations and regional declines of endemic upper beach invertebrates in southern California

    NASA Astrophysics Data System (ADS)

    Hubbard, D. M.; Dugan, J. E.; Schooler, N. K.; Viola, S. M.

    2014-10-01

    Along the world's highly valued and populous coastlines, the upper intertidal zones of sandy beach ecosystems and the biodiversity that these zones support are increasingly threatened by impacts of human activities, coastal development, erosion, and climate change. The upper zones of beaches typically support invertebrates with restricted distributions and dispersal, making them particularly vulnerable to habitat loss and fragmentation. We hypothesized that disproportionate loss or degradation of these zones in the last century has resulted in declines of upper shore macroinvertebrates in southern California. We identified a suite of potentially vulnerable endemic upper beach invertebrates with direct development, low dispersal and late reproduction. Based on the availability of printed sources and museum specimens, we investigated historical changes in distribution and abundance of two intertidal isopod species (Tylos punctatus, Alloniscus perconvexus) in southern California. Populations of these isopods have been extirpated at numerous historically occupied sites: T. punctatus from 16 sites (57% decrease), and A. perconvexus from 14 sites (64% decrease). During the same period, we found evidence of only five colonization events. In addition, the northern range limit of the southern species, T. punctatus, moved south by 31 km (8% of range on California mainland) since 1971. Abundances of T. punctatus have declined on the mainland coast; only three recently sampled populations had abundances >7000 individuals m-1. For A. perconvexus populations, abundances >100 individuals m-1 now appear to be limited to the northern part of the study area. Our results show that numerous local extirpations of isopod populations have resulted in regional declines and in greatly reduced population connectivity in several major littoral cells of southern California. Two of the six major littoral cells (Santa Barbara and Zuma) in the area currently support 74% of the remaining isopod populations. These isopods persist primarily on relatively remote, ungroomed, unarmored beaches with restricted vehicle access and minimal management activity. These predominantly narrow, bluff-backed beaches also support species-rich upper beach assemblages, suggesting these isopods can be useful indicators of biodiversity. The high extirpation rates of isopod populations on the southern California mainland over the last century provide a compelling example of the vulnerability of upper beach invertebrates to coastal urbanization. Climate change and sea level rise will exert further pressures on upper beach zones and biota in southern California and globally. In the absence of rapid implementation of effective conservation strategies, our results suggest many upper intertidal invertebrate species are at risk.

  1. ERADICATION OF NON-NATIVE MAMMALS AND THE STATUS OF INSULAR MAMMALS ON THE CALIFORNIA CHANNEL ISLANDS, USA, AND PACIFIC BAJA CALIFORNIA PENINSULA ISLANDS, MEXICO

    Microsoft Academic Search

    Jessie L. Knowlton; C. Josh Donlan; Gary W. Roemer; Araceli Samaniego-Herrera; Bradford S. Keitt; Bill Wood; Alfonso Aguirre-Muñoz; Kate R. Faulkner; Bernie R. Tershy

    2007-01-01

    ABSTRACT—The California Channel Islands, USA, and Pacific Baja California Peninsula Islands, Mexico (hereafter referred to as the California islands), are known for their high levels of biodiversity and globally important colonies of seabirds. We document the history, impacts, and management of non-native mammals and summarize the current status of native, non-volant mammals on the California islands. Of the 26 species

  2. Climate Change and Arctic Ecosystems

    NSDL National Science Digital Library

    Project Activities for Conceptualizing Climate and Climate Change

    In this activity, students learn about how climate change is affecting the Arctic ecosystem and then investigate how this change is impacting polar bear populations. Students analyze maps of Arctic sea ice, temperature graphs, and polar bear population data to answer questions about the impact of climate change on the Arctic ecosystem.

  3. Ecosystem adaptation to scarce nutrient resources: Do forest ecosystems shift from acquisition to recycling of phosphorus?

    NASA Astrophysics Data System (ADS)

    Lang, F.; Kaupenjohann, M.

    2011-12-01

    Friederike Lang(1, Nicole Wellbrock(2, Martin Kaupenjohann(1 (1) Department of Soil Science, TU Berlin, 10587 Berlin, Germany; (2) vTI Eberswalde Agricultural food production is essential to our existence, yet we are using up the Earths stocks of phosphorus (P) for the fertilizer production (Cordell, 2009). Forest ecosystems that developed on marginal soil have developed highly efficient strategies for the uptake, usage and recycling of P, which might inspire solutions for the problem of P scarcity in agriculture. However, these efficient forest strategies are hardly investigated yet. Current literature concepts on the adaptation to low soil-P supply are mainly refined to individual organisms (e.g. the concept of uptake efficiency, Sattelmacher et al., 1994, and utilisation efficiency of plants, Compton and Cole, 1998). At the ecosystem level, however, low mineral-P supply requires an evolution of the system towards closed biogeochemical cycling (the concept of cycling efficiency). At the ecosystem level nutrient efficiency becomes rather a matter of transfer and distribution of resources among species, generations and soil components than of the capability of single organisms to acquire P sources. We plead for introducing the term ecosystem nutrition to cover this topic. Our general hypothesis is that P depletion of soils drives the development of forest ecosystems from geochemical P acquiring systems (mobilisation of P from the mineral phase) to biogeochemical P recycling systems (recycling of P from soil organic matter). We conclude that fundamental knowledge in the area of ecosystem nutrition is essential for forestry to mitigate the consequences of increasing N deposition, climate change and intensification of forest usage, which most likely interfere with essential nutrition strategies of forest ecosystems. Transfer of the knowledge on nutrition strategies and resource management of near-natural ecosystems to/in agricultural systems may finally contribute to counteract one of the most severe shortages of a natural resource humanity has ever faced in history. Compton, J.E., Cole, D.W. (1998). Forest Ecology and Management 110 (1-3) 101-112. Cordell et al. 2009, Global Env. Change, 19:292-305. Sattelmacher, B. , Horst, Becker (1994): Zeitschrift für Pflanzenernährung und Bodenkunde 157, 215-224.

  4. Ecosystems, Organisms, and Machines

    NSDL National Science Digital Library

    EVELYN FOX KELLER (; )

    2005-12-01

    This peer reviewed article from Bioscience is about is the concept, and the term, "self-organization." The history of this term, originally introduced by Immanuel Kant to characterize the unique properties of living organisms, is inseparable from the history of biology. Only in the second half of the 20th century does it begin to acquire the promise of a physicalistic understanding. This it does with two critical transformations in the meaning of the term: first, with the advent of cybernetics and its dissolution of the boundary between organisms and machines, and second, with the mathematical triumphs of nonlinear dynamical systems theory and accompanying claims to having dissolved the boundary between organisms and such physical phenomena as thunderstorms. How do these transformations affect the applicability of self-organization to the ecosystem--that provocatively hybrid entity that is part organism, part machine, and perhaps even part thunderstorm?

  5. 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

  6. Linking ecosystem characteristics to final ecosystem services for public policy

    PubMed Central

    Wong, Christina P; Jiang, Bo; Kinzig, Ann P; Lee, Kai N; Ouyang, Zhiyun

    2015-01-01

    Governments worldwide are recognising ecosystem services as an approach to address sustainability challenges. Decision-makers need credible and legitimate measurements of ecosystem services to evaluate decisions for trade-offs to make wise choices. Managers lack these measurements because of a data gap linking ecosystem characteristics to final ecosystem services. The dominant method to address the data gap is benefit transfer using ecological data from one location to estimate ecosystem services at other locations with similar land cover. However, benefit transfer is only valid once the data gap is adequately resolved. Disciplinary frames separating ecology from economics and policy have resulted in confusion on concepts and methods preventing progress on the data gap. In this study, we present a 10-step approach to unify concepts, methods and data from the disparate disciplines to offer guidance on overcoming the data gap. We suggest: (1) estimate ecosystem characteristics using biophysical models, (2) identify final ecosystem services using endpoints and (3) connect them using ecological production functions to quantify biophysical trade-offs. The guidance is strategic for public policy because analysts need to be: (1) realistic when setting priorities, (2) attentive to timelines to acquire relevant data, given resources and (3) responsive to the needs of decision-makers. PMID:25394857

  7. Linking ecosystem characteristics to final ecosystem services for public policy.

    PubMed

    Wong, Christina P; Jiang, Bo; Kinzig, Ann P; Lee, Kai N; Ouyang, Zhiyun

    2015-01-01

    Governments worldwide are recognising ecosystem services as an approach to address sustainability challenges. Decision-makers need credible and legitimate measurements of ecosystem services to evaluate decisions for trade-offs to make wise choices. Managers lack these measurements because of a data gap linking ecosystem characteristics to final ecosystem services. The dominant method to address the data gap is benefit transfer using ecological data from one location to estimate ecosystem services at other locations with similar land cover. However, benefit transfer is only valid once the data gap is adequately resolved. Disciplinary frames separating ecology from economics and policy have resulted in confusion on concepts and methods preventing progress on the data gap. In this study, we present a 10-step approach to unify concepts, methods and data from the disparate disciplines to offer guidance on overcoming the data gap. We suggest: (1) estimate ecosystem characteristics using biophysical models, (2) identify final ecosystem services using endpoints and (3) connect them using ecological production functions to quantify biophysical trade-offs. The guidance is strategic for public policy because analysts need to be: (1) realistic when setting priorities, (2) attentive to timelines to acquire relevant data, given resources and (3) responsive to the needs of decision-makers. PMID:25394857

  8. NASA COAST and OCEANIA Airborne Missions Support Ecosystem and Water Quality Research in the Coastal Zone

    NASA Astrophysics Data System (ADS)

    Guild, L. S.; Kudela, R. M.; Hooker, S. B.; Morrow, J. H.; Russell, P. B.; Palacios, S. L.; Livingston, J. M.; Negrey, K.; Torres-Perez, J. L.; Broughton, J.

    2014-12-01

    NASA has a continuing requirement to collect high-quality in situ data for the vicarious calibration of current and next generation ocean color satellite sensors and to validate the algorithms that use the remotely sensed observations. Recent NASA airborne missions over Monterey Bay, CA, have demonstrated novel above- and in-water measurement capabilities supporting a combined airborne sensor approach (imaging spectrometer, microradiometers, and a sun photometer). The results characterize coastal atmospheric and aquatic properties through an end-to-end assessment of image acquisition, atmospheric correction, algorithm application, plus sea-truth observations from state-of-the-art instrument systems. The primary goal is to demonstrate the following in support of calibration and validation exercises for satellite coastal ocean color products: 1) the utility of a multi-sensor airborne instrument suite to assess the bio-optical properties of coastal California, including water quality; and 2) the importance of contemporaneous atmospheric measurements to improve atmospheric correction in the coastal zone. The imaging spectrometer (Headwall) is optimized in the blue spectral domain to emphasize remote sensing of marine and freshwater ecosystems. The novel airborne instrument, Coastal Airborne In-situ Radiometers (C-AIR) provides measurements of apparent optical properties with high dynamic range and fidelity for deriving exact water leaving radiances at the land-ocean boundary, including radiometrically shallow aquatic ecosystems. Simultaneous measurements supporting empirical atmospheric correction of image data are accomplished using the Ames Airborne Tracking Sunphotometer (AATS-14). Flight operations are presented for the instrument payloads using the CIRPAS Twin Otter flown over Monterey Bay during the seasonal fall algal bloom in 2011 (COAST) and 2013 (OCEANIA) to support bio-optical measurements of phytoplankton for coastal zone research.

  9. Using plant traits to evaluate the resistance and resilience of ecosystem service provision

    NASA Astrophysics Data System (ADS)

    Kohler, Marina; Devaux, Caroline; Fontana, Veronika; Grigulis, Karl; Lavorel, Sandra; Leitinger, Georg; Schirpke, Uta; Tasser, Erich; Tappeiner, Ulrike

    2015-04-01

    Mountain grassland ecosystems are a hotspot of biodiversity and deliver a multiplicity of ecosystem services. Due to a long history of well adapted agricultural use and specific environmental conditions (e.g. slope, altitude, or climate), various types of grassland ecosystems have developed. Each of them shows specific attributes in forms of plant communities and abiotic characteristics, which lead to particular ranges of ecosystem service provision. However, ongoing climate and societal changes thread plant community composition and may lead to changes in plant traits, and therefore, the provision of ecosystem services. Currently it is not clear how vulnerable these ecosystems are to disturbances, or whether they have developed a high resilience over time. Thus, it is essential to know the ranges of resistance and resilience of an ecosystem service. We, therefore, developed a static approach based on community weighted mean plant traits and abiotic parameters to measure the boundaries of resistance and resilience of each ecosystem service separately. By calculating actual minimum and maximum amounts of ecosystem services, we define the range of resistance of an ecosystem service. We then calculate the potential amount of an ecosystem services (via simulated plant communities) by assuming that no species is lost or added to the system. By comparing actual and potential values, we can estimate whether an ecosystem service is in danger to lose its resilience. We selected different ecosystem services related to mountain grassland ecosystems, e.g. carbon storage, forage quality, forage quantity, and soil fertility. We analysed each ecosystem service for different grassland management types, covering meadows and pastures of very low land-use intensity through to grasslands of high land-use intensity. Results indicate that certain ecosystem services have a higher resilience than others (e.g. carbon storage) for all management types. The ecosystem may provide steady amounts of ecosystem services also in future when facing environmental or societal disturbances. In contrary, other services are very depending on actual conditions and are, therefore, less stable (e.g. forage quantity). When comparing ranges of resistance and resilience, the actual amount lies very close to the boundaries of the potential provision. This gives us a hint that the ecosystem service is in danger to lose its resilience and amount of ecosystem service provision when facing disturbances in future.

  10. Evolution of local facilitation in arid ecosystems.

    PubMed

    Kéfi, Sonia; van Baalen, Minus; Rietkerk, Max; Loreau, Michel

    2008-07-01

    In harsh environments, sessile organisms can make their habitat more hospitable by buffering environmental stress or increasing resource availability. Although the ecological significance of such local facilitation is widely established, the evolutionary aspects have been seldom investigated. Yet addressing the evolutionary aspects of local facilitation is important because theoretical studies show that systems with such positive interactions can exhibit alternative stable states and that such systems may suddenly become extinct when they evolve (evolutionary suicide). Arid ecosystems currently experience strong changes in climate and human pressures, but little is known about the effects of these changes on the selective pressures exerted on the vegetation. Here, we focus on the evolution of local facilitation in arid ecosystems, using a lattice-structured model explicitly considering local interactions among plants. We found that the evolution of local facilitation depends on the seed dispersal strategy. In systems characterized by short-distance seed dispersal, adaptation to a more stressful environment leads to high local facilitation, allowing the population to escape extinction. In contrast, systems characterized by long-distance seed dispersal become extinct under increased stress even when allowed to adapt. In this case, adaptation in response to climate change and human pressures could give the final push to the desertification of arid ecosystems. PMID:18554137

  11. Hydrologic Response and Watershed Sensitivity to Climate Warming in California's Sierra Nevada

    PubMed Central

    Null, Sarah E.; Viers, Joshua H.; Mount, Jeffrey F.

    2010-01-01

    This study focuses on the differential hydrologic response of individual watersheds to climate warming within the Sierra Nevada mountain region of California. We describe climate warming models for 15 west-slope Sierra Nevada watersheds in California under unimpaired conditions using WEAP21, a weekly one-dimensional rainfall-runoff model. Incremental climate warming alternatives increase air temperature uniformly by 2°, 4°, and 6°C, but leave other climatic variables unchanged from observed values. Results are analyzed for changes in mean annual flow, peak runoff timing, and duration of low flow conditions to highlight which watersheds are most resilient to climate warming within a region, and how individual watersheds may be affected by changes to runoff quantity and timing. Results are compared with current water resources development and ecosystem services in each watershed to gain insight into how regional climate warming may affect water supply, hydropower generation, and montane ecosystems. Overall, watersheds in the northern Sierra Nevada are most vulnerable to decreased mean annual flow, southern-central watersheds are most susceptible to runoff timing changes, and the central portion of the range is most affected by longer periods with low flow conditions. Modeling results suggest the American and Mokelumne Rivers are most vulnerable to all three metrics, and the Kern River is the most resilient, in part from the high elevations of the watershed. Our research seeks to bridge information gaps between climate change modeling and regional management planning, helping to incorporate climate change into the development of regional adaptation strategies for Sierra Nevada watersheds. PMID:20368984

  12. Endangered California Condor

    USGS Multimedia Gallery

    An endangered California condor flies over the Bitter Creek National Wildlife Refuge, California. USGS scientists are helping managers understand how California condors use their habitat, gaining valuable information that will help inform not only which potential energy development sites are likely ...

  13. NORTHERN CALIFORNIA METALLURGICAL SECTION

    E-print Network

    Wu, Junqiao

    , California COFFEE BREASt "V--MOS Technology" Dr. Thurman J. Rodgers American Micro--Systems, Inc. Santa Clara Clara, California 3:00 COFFEE SREAR 3:30 "Recent Advances in Electroluminescent Memory Devices" Dr will be presented to Berry L. Chin, Department of Mmteriala Science, University of California, Berkeley, for his

  14. California Sea Grant 1 California Sea Grant

    E-print Network

    Jaffe, Jules

    California Sea Grant 1 California Sea Grant Strategic Plan 2010­2013 #12;2 Strategic Plan 2010­2013 The National Sea Grant College Program, U.S. Department of Commerce, National Oceanic and Atmospheric Administration, supported this publication under NOAA grant number NA08OAR4170669, project number C/P-1 through

  15. What Has Created California's School Facilities Predicament? EdFact.

    ERIC Educational Resources Information Center

    EdSource, Inc., Palo Alto, CA.

    The growth in California's student population currently exceeds the peak years of the baby boom generation by more than one million students. This increase, combined with deferred maintenance, has created a strain on the state's educational facilities. An analysis of this predicament is presented in this bulletin. It describes why California needs…

  16. Control of the California Extremely Large Telescope Primary Mirror

    E-print Network

    MacMynowski, Douglas G. - MacMynowski, Douglas G.

    Control of the California Extremely Large Telescope Primary Mirror Douglas G. MacMartina and Gary The current design concept for the California Extremely Large Telescope (CELT) includes 1080 segments from the Keck telescopes are used to generate realistic estimates of the control system contributions

  17. EXPOSURES AND HEALTH OF FARM WORKER CHILDREN IN CALIFORNIA

    EPA Science Inventory

    The EPA STAR Program Center of Excellence in Children's Environmental Health and Disease Prevention Research at the University of California at Berkeley is currently conducting exposure and health studies for children of farm workers in the Salinas Valley of California. The Exp...

  18. Cooperative Activities of the University of California Libraries.

    ERIC Educational Resources Information Center

    Beaupre, Linda

    The report documents current cooperation activities between University of California (UC) libraries and others. Information about programs, procedures, and agreements was gathered in the fall of 1976 from staff members at the nine UC campuses and from librarians at other California institutions. Information sharing between on-campus and off-campus…

  19. Climate impact on net ecosystem productivity of a semi-arid natural grassland: modeling and measurement

    Microsoft Academic Search

    Tao Li; Robert F. Grant; Lawrence B. Flanagan

    2004-01-01

    Models used to estimate net ecosystem productivity (NEP) during climate change should first be shown to simulate the effects on NEP of interannual variability in current climates. Energy and CO2 fluxes simulated by the ecosystem model ecosys were compared with those measured by eddy covariance over a semi-arid ungrazed grassland near Lethbridge, Alberta to improve confidence in model projections of

  20. Restructuring Juvenile Corrections in California: A Report to the State Legislature

    ERIC Educational Resources Information Center

    Nadel-Hayes, Sele; Macallair, Daniel

    2005-01-01

    Youth corrections in California is at a crossroads. In response to the near universal recognition of California's failed approach to youth corrections, Governor Schwarzenegger, with support from the California Legislature, has launched one of the largest restructuring initiatives of youth corrections in state history. Reforms currently underway…

  1. STATUS AND HABITAT USE OF THE CALIFORNIA BLACK RAIL IN THE SOUTHWESTERN USA

    Microsoft Academic Search

    Courtney J. Conway; Christina Sulzman

    2007-01-01

    California black rails (Laterallus jamaicensis coturniculus) occur in two disjunct regions: the southwestern USA (western Arizona and southern California) and northern California (Sacramento Valley and the San Francisco Bay area). We examined current status of black rails in the southwestern USA by repeating survey efforts first conducted in 1973-1974 and again in 1989, and also examined wetland plant species associated

  2. Unraveling the Myths of Accountability: A Case Study of the California High School Exit Exam

    ERIC Educational Resources Information Center

    Ullucci, Kerri; Spencer, Joi

    2009-01-01

    Believing that accountability could be a vehicle for change, the California Department of Education (CDE) requires all high school students to pass the California High School Exit Exam (CAHSEE) in order to graduate. In doing so, California joins many others states in mandating a high school exit exam as a current or future requirement for…

  3. Ash in fire affected ecosystems

    NASA Astrophysics Data System (ADS)

    Pereira, Paulo; Jordan, Antonio; Cerda, Artemi; Martin, Deborah

    2015-04-01

    Ash in fire affected ecosystems Ash lefts an important footprint in the ecosystems and has a key role in the immediate period after the fire (Bodi et al., 2014; Pereira et al., 2015). It is an important source of nutrients for plant recover (Pereira et al., 2014a), protects soil from erosion and controls soil hydrological process as runoff, infiltration and water repellency (Cerda and Doerr, 2008; Bodi et al., 2012, Pereira et al., 2014b). Despite the recognition of ash impact and contribution to ecosystems recuperation, it is assumed that we still have little knowledge about the implications of ash in fire affected areas. Regarding this situation we wanted to improve our knowledge in this field and understand the state of the research about fire ash around world. The special issue about "The role of ash in fire affected ecosystems" currently in publication in CATENA born from the necessity of joint efforts, identify research gaps, and discuss future cooperation in this interdisciplinary field. This is the first special issue about fire ash in the international literature. In total it will be published 10 papers focused in different aspects of the impacts of ash in fire affected ecosystems from several parts of the world: • Fire reconstruction using charcoal particles (Burjachs and Espositio, in press) • Ash slurries impact on rheological properties of Runoff (Burns and Gabet, in press) • Methods to analyse ash conductivity and sorbtivity in the laboratory and in the field (Balfour et al., in press) • Termogravimetric and hydrological properties of ash (Dlapa et al. in press) • Effects of ash cover in water infiltration (Leon et al., in press) • Impact of ash in volcanic soils (Dorta Almenar et al., in press; Escuday et al., in press) • Ash PAH and Chemical extracts (Silva et al., in press) • Microbiology (Barreiro et al., in press; Lombao et al., in press) We believe that this special issue will contribute importantly to the better understanding of the role of ash in fire affected areas. Acknowledgments The 'Litfire' Project (MIP-048/2011; 181 Pereira) funded by the Lithuanian Research Council, Soil quality, erosion control and plant cover recovery under different post-firemanagement scenarios (POSTFIRE), funded by the Spanish Ministry of Economy and Competitiveness (CGL2013-47862-C2-1-R), Preventing and Remediating Degradation of Soils in Europe Through Land Care (RECARE) funded by the European Commission (FP7-ENV-2013-TWO STAGE) and European Research Project LEDDRA (243857) and COST action ES1306 (Connecting European connectivity research). References Balfour, V.N., Determining wildfire ash saturated hydraulic conductivity and sorptivity with laboratory and field methods. Catena. doi:10.1016/j.catena.2014.01.009 Barreiro, A., Fontúrbel, M.T., Lombao, A., Martín, C., Vega, J.A., Fernández, C., Carballas, T., Díaz-Raviña, M., Using phospholipid fatty acid and community level physiological profiling techniques to characterize soil microbial communities following an experimental fire and different stabilization treatments. Catena. doi:10.1016/j.catena.2014.07.011 Bodi, M., Martin, D.A., Santin, C., Balfour, V., Doerr, S.H., Pereira, P., Cerda, A., Mataix-Solera, J. (2014) Wildland fire ash: production, composition and eco-hydro-geomorphic effects. Earth-Science Reviews, 130, 103-127. Bodí, M.B., Doerr, S.H., Cerdà, A. and Mataix-Solera, J. (2012) Hydrological effects of a layer of vegetation ash on underlying wettable and water repellent soils. Geoderma, 191, 14-23. Burjachs, F., Expósito, I., Charcoal and pollen analysis: examples of Holocene fire dynamics in Mediterranean Iberian Peninsula. Catena. doi:10.1016/j.catena.2014.10.006 Burns, K., Gabet, E., The effective viscosity of slurries laden with vegetative ash. Catena. doi:10.1016/j.catena.2014.06.008 Cerdà, A. Doerr, S.H. (2008). The effect of ash and needle cover on surface runoff and erosion in the immediate post-fire period. Catena, 74 , 256-263. Dlapa, P., Bodí, M.B., Mataix-Solera, J., Cerdà, A., Doerr, S.H., Organic matter

  4. Parasites of the superorganism: are they indicators of ecosystem health?

    PubMed

    Marcogliese, David J

    2005-06-01

    The concept of ecosystem health is derived from analogies with human health, which subsequently leads to the implication that the ecosystem has organismal properties, a 'superorganism' in the Clementsian sense. Its application and usefulness has been the subject of a contentious debate; yet, the term 'ecosystem health' has captured the public's imagination and woven its way into the current lexicon, even incorporated into public policy. However, the application of parasites as bioindicators of ecosystem health poses a curious conundrum. Perceptions of parasites range from mild distaste to sheer disgust among the general public, the media, environmental managers and non-parasitologists in the scientific community. Nevertheless, the biological nature of parasitism incorporates natural characteristics that are informative and useful for environmental management. The helminths in particular have evolved elegant means to ensure their transmission, often relying on complex life cycle interactions that include a variety of invertebrate and vertebrate hosts. The assemblage of these diverse parasites within a host organism potentially reflect that host's trophic position within the food web as well as the presence in the ecosystem of any other organisms that participate in the various parasite life cycles. Perturbations in ecosystem structure and function that affect food web topology will also impact upon parasite transmission, thus affecting parasite species abundance and composition. As such, parasite populations and communities are useful indicators of environmental stress, food web structure and biodiversity. In addition, there may be useful other means to utilise parasitic organisms based on their biology and life histories such as suites or guilds that may be effective bioindicators of particular forms of environmental degradation. The challenge for parasitology is to convince resource managers and fellow scientists that parasites are a natural part of all ecosystems, each species being a potentially useful information unit, and that healthy ecosystems have healthy parasites. PMID:15925594

  5. Linking Water Quality and Quantity in Environmental Flow Assessment in Deteriorated Ecosystems: A Food Web View

    PubMed Central

    Chen, He; Ma, Lekuan; Guo, Wei; Yang, Ying; Guo, Tong; Feng, Cheng

    2013-01-01

    Most rivers worldwide are highly regulated by anthropogenic activities through flow regulation and water pollution. Environmental flow regulation is used to reduce the effects of anthropogenic activities on aquatic ecosystems. Formulating flow alteration–ecological response relationships is a key factor in environmental flow assessment. Traditional environmental flow models are characterized by natural relationships between flow regimes and ecosystem factors. However, food webs are often altered from natural states, which disturb environmental flow assessment in such ecosystems. In ecosystems deteriorated by heavy anthropogenic activities, the effects of environmental flow regulation on species are difficult to assess with current modeling approaches. Environmental flow management compels the development of tools that link flow regimes and food webs in an ecosystem. Food web approaches are more suitable for the task because they are more adaptive for disordered multiple species in a food web deteriorated by anthropogenic activities. This paper presents a global method of environmental flow assessment in deteriorated aquatic ecosystems. Linkages between flow regimes and food web dynamics are modeled by incorporating multiple species into an ecosystem to explore ecosystem-based environmental flow management. The approach allows scientists and water resources managers to analyze environmental flows in deteriorated ecosystems in an ecosystem-based way. PMID:23894669

  6. Hotspots of Ecosystem Services on Floodplains in the Interior Columbia Basin

    NASA Astrophysics Data System (ADS)

    Tomscha, S. A.; Gergel, S.

    2011-12-01

    Rapid land use conversion over the past 60 years has led to the production and depletion of different ecosystem services throughout the Interior Columbia Basin producing unintended tradeoffs among services. For example, increases in cultivation and urbanization have driven a reduction in floodplain fish habitat and carbon storage. Furthermore, ecosystem service hotspots (areas critical for ecosystem service production) have shifted in location and extent. The enormity of such tradeoffs remains unquantified as mapping of historical ecosystem services is in its infancy. Our research addresses ecosystem services over two timeframes: (1) Where are historical hotspots of ecosystem services in floodplains in the mid-20th century? and (2) Has the location of hotspots changed in current times? We develop a novel combination of tools to map terrestrial and riparian ecosystem services across a floodplain. We combine historical aerial photography with InVEST (Integrated Valuation of Ecosystem Services and Tradeoff tools), a spatial program designed to model and identify hotspots of ecosystem services such as carbon sequestration, biodiversity, water purification, etc. Mapping and quantifying ecosystem services provides a long-term look at the potential for the Interior Columbia Basin to produce a multitude of sustainable floodplain services.

  7. Ultraviolet radiation affects invasibility of lake ecosystems by warm-water fish.

    PubMed

    Tucker, Andrew J; Williamson, Craig E; Rose, Kevin C; Oris, James T; Connelly, Sandra J; Olson, Mark H; Mitchell, David L

    2010-03-01

    Predicting where species invasions will occur remains a substantial challenge in ecology, but identifying factors that ultimately constrain the distribution of potential invaders could facilitate successful prediction. Whereas ultraviolet radiation (UVR) is recognized as an important factor controlling species distribution and community composition, the role of UVR in a habitat invasibility context has not been explored. Here we examine how underwater UVR can regulate warm-water fish invasion. In Lake Tahoe, California and Nevada, USA, established populations of exotic bluegill sunfish (Lepomis macrochirus) are currently limited to turbid, low-UVR embayments. An in situ incubation experiment that manipulated incident UVR exposure of larval bluegill, combined with an assessment of UVR exposure levels in nearshore habitats around Lake Tahoe, demonstrates that UVR can mediate habitat invasibility. Our findings suggest that the susceptibility to invasion by UVR sensitive species may increase in transparent aquatic systems threatened by declining water quality, and they highlight the importance of abiotic factors as regulators of invasion risk in ecosystems. PMID:20426345

  8. Forest ecosystems: Vegetation, disturbance, and economics: Chapter 5

    USGS Publications Warehouse

    Littell, Jeremy S.; Hicke, Jeffrey A.; Shafer, Sarah L.; Capalbo, Susan M.; Houston, Laurie L.; Glick, Patty

    2013-01-01

    Forests cover about 47% of the Northwest (NW–Washington, Oregon, and Idaho) (Smith et al. 2009, fig. 5.1, table 5.1). The impacts of current and future climate change on NW forest ecosystems are a product of the sensitivities of ecosystem processes to climate and the degree to which humans depend on and interact with those systems. Forest ecosystem structure and function, particularly in relatively unmanaged forests where timber harvest and other land use have smaller effects, is sensitive to climate change because climate has a strong influence on ecosystem processes. Climate can affect forest structure directly through its control of plan physiology and life history (establishment, individual growth, productivity, and morality) or indirectly through its control of disturbance (fire, insects, disease). As climate changes, many forest processes will be affected, altering ecosystem services such as timber production and recreation. These changes have socioeconomic implications (e.g. for timber economies) and will require changes to current management of forests. Climate and management will interact to determine the forests of the future, and the scientific basis for adaptation to climate change in forests thus depends significantly on how forests will be affected.

  9. Ecosystem services and environmental decision making: seeking order in complexity.

    PubMed

    Apitz, Sabine E

    2013-04-01

    The Ecosystem Service Paradigm (EsSP) is increasingly a component or even an underlying principle of environmental policy, legislation and management internationally. The EsSP can be used to define links between human activities and ecosystems, and ecosystems and the services that in turn support and sustain those and other activities; this information can then be used to evaluate, justify or optimize decisions. However, how EsS within various practical applications and frameworks are applied, defined, quantified, modelled, valued and communicated ranges widely, potentially hindering their roles as cross-sectoral tools. For this paradigm to be useful for cross-disciplinary integration, it is important that practitioners in different fields are clear about what is meant and assumed when terms are used, and within what context assessments are being carried out. The logic behind practical applications of the EsSP can be explained by the EsS Decision Cascade, a three-part, iterative conceptual framework. Within the decision cascade, Ecosystem Service Decision Analysis (EsSD) defines the proposed policies or actions (scenarios), and the changes/pressures under consideration in different scenarios. Within the context laid out by EsSD, Ecosystem Service Assessment (EsSA) will then evaluate how such changes affect biophysical structure, and thus ecosystem function and services; Ecosystem Service Valuation (EsSV) then takes the results from these analyses and generates valuations to inform decisions; linking back to EsSD. EsS-based evaluations can expand the current risk-focused thinking behind ecological risk assessment (ERA) to consider trade-offs between a range of desirable and undesirable responses of a variety of ecosystem endpoints; such an assessment can be termed an Ecosystem Response Assessment (EcoResA), or if applied in a spatially explicit manner, an Ecosystem Regional Assessment (EcoRegA); understanding of such trade-offs is essential to inform decisions about more sustainable remediation, regulation and management of landscapes and resources. This paper describes "taxonomies" of various aspects of EsSP applications, based upon their decision context, perspective and assessment approach. It then examines, with a focus on European issues, a range of current and emerging regulatory and management applications to which the EsSP can be applied in light of this taxonomy. PMID:23281271

  10. CANAL DATA FOR SOUTH FLORIDA ECOSYSTEM ASSESSMENT PROJECT

    EPA Science Inventory

    The South Florida Ecosystem Assessment Project is an innovative, large-scale monitoring and assessment program designed to measure current and changing conditions of ecological resources in South Florida using an integrated holistic approach. This data set contains results for f...

  11. MARSH DATA FOR SOUTH FLORIDA ECOSYSTEM ASSESSMENT PROJECT

    EPA Science Inventory

    The South Florida Ecosystem Assessment Project is an innovative, large-scale monitoring and assessment program designed to measure current and changing conditions of ecological resources in South Florida using an integrated holistic approach. This data set contains results for f...

  12. Sound management may sequester methane in grazed rangeland ecosystems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Considering their contribution to global warming, the sources and sinks of methane (CH4) should be accounted when undertaking a greenhouse gas inventory for grazed rangeland ecosystems. The aim of this study was to evaluate the mitigation potential of current ecological management programs implement...

  13. Assessing Pathogen and Insect Succession Functions in Forest Ecosystems

    Microsoft Academic Search

    Susan K. Hagle; Sandra Kegley; Stephen B. Williams

    The pilot test of a method to assess the ecological function of patho- gens and insects in forests is reported. The analysis is a practical application of current ecosystem management theory.The influences of pathogens and insects on forest succession are measured by relating successional transition rates and types to conditions for pathogen and insect activities which are expected to lead

  14. Comparison of Coral Reef Ecosystems along a Fishing Pressure Gradient

    E-print Network

    Three trophic mass-balance models representing coral reef ecosystems along a fishery gradient were that indicators at the community level (e.g., total biomass, community size structure, trophic level complement biological metrics currently used by monitoring programs as indicators for coral reef status

  15. Optimal Rooting Profiles in Water-Limited Ecosystems

    Microsoft Academic Search

    D. B. Collins; R. L. Bras

    2005-01-01

    Plant rooting profiles vary with climatic, edaphic and physiological factors, which, in water-limited ecosystems, has been largely attributed to hydrotrophism. However, current field data provide only a qualitative explanation, and are limited in their range of environmental variables. This study tests whether the hydrotrophic model is sufficient to explain observations of rooting profiles quantitatively, and to elaborate on the causal

  16. Coral Reef Ecosystems

    NASA Astrophysics Data System (ADS)

    Yap, Helen T.

    Coral reefs are geological structures of significant dimensions, constructed over millions of years by calcifying organisms. The present day reef-builders are hard corals belonging to the order Scleractinia, phylum Cnidaria. The greatest concentrations of coral reefs are in the tropics, with highest levels of biodiversity situated in reefs of the Indo-West Pacific region. These ecosystems have provided coastal protection and livelihood to human populations over the millennia. Human activities have caused destruction of these habitats, the intensity of which has increased alarmingly since the latter decades of the twentieth century. The severity of this impact is directly related to exponential growth rates of human populations especially in the coastal areas of the developing world. However, a more recently recognized phenomenon concerns disturbances brought about by the changing climate, manifested mainly as rising sea surface temperatures, and increasing acidification of ocean waters due to greater drawdown of higher concentrations of atmospheric carbon dioxide. Management efforts have so far not kept pace with the rates of degradation, so that the spatial extent of damaged reefs and the incidences of localized extinction of reef species are increasing year after year. The major management efforts to date consist of establishing marine protected areas and promoting the active restoration of coral habitats.

  17. Mercury in the ecosystem

    SciTech Connect

    Mitra, S.

    1986-01-01

    This treatise on the environmental dispersion of mercury emphasizes the importance of ''mercury-consciousness'' in the present-day world, where rapidly expanding metallurgical, chemical, and other industrial developments are causing widespread contamination of the atmosphere, soil, and water by this metal and its toxic organic derivatives. Concepts concerning the mechanism of mercury dispersion and methyl-mercury formation in the physico-biological ecosystem are discussed in detail and a substantial body of data on the degree and nature of the mercury contamination of various plants, fish, and land animals by industrial and urban effluents is presented. Various analytical methods for the estimation of mercury in inorganic and organic samples are presented. These serve as a ready guide to the selection of the correct method for analyzing environmental samples. This book is reference work in mercury-related studies. It is written to influence industrial policies of governments in their formulation of control measures to avoid the recurrence of human tragedies such as the well-known Minamata case in Japan, and the lesser known cases in Iraq, Pakistan, and Guatamala.

  18. Impacts of pesticides in a Central California estuary.

    PubMed

    Anderson, Brian; Phillips, Bryn; Hunt, John; Siegler, Katie; Voorhees, Jennifer; Smalling, Kelly; Kuivila, Kathy; Hamilton, Mary; Ranasinghe, J Ananda; Tjeerdema, Ron

    2014-03-01

    Recent and past studies have documented the prevalence of pyrethroid and organophosphate pesticides in urban and agricultural watersheds in California. While toxic concentrations of these pesticides have been found in freshwater systems, there has been little research into their impacts in marine receiving waters. Our study investigated pesticide impacts in the Santa Maria River estuary, which provides critical habitat to numerous aquatic, terrestrial, and avian species on the central California coast. Runoff from irrigated agriculture constitutes a significant portion of Santa Maria River flow during most of the year, and a number of studies have documented pesticide occurrence and biological impacts in this watershed. Our study extended into the Santa Maria watershed coastal zone and measured pesticide concentrations throughout the estuary, including the water column and sediments. Biological effects were measured at the organism and community levels. Results of this study suggest the Santa Maria River estuary is impacted by current-use pesticides. The majority of water samples were highly toxic to invertebrates (Ceriodaphnia dubia and Hyalella azteca), and chemistry evidence suggests toxicity was associated with the organophosphate pesticide chlorpyrifos, pyrethroid pesticides, or mixtures of both classes of pesticides. A high percentage of sediment samples were also toxic in this estuary, and sediment toxicity occurred when mixtures of chlorpyrifos and pyrethroid pesticides exceeded established toxicity thresholds. Based on a Relative Benthic Index, Santa Maria estuary stations where benthic macroinvertebrate communities were assessed were degraded. Impacts in the Santa Maria River estuary were likely due to the proximity of this system to Orcutt Creek, the tributary which accounts for most of the flow to the lower Santa Maria River. Water and sediment samples from Orcutt Creek were highly toxic to invertebrates due to mixtures of the same pesticides measured in the estuary. This study suggests that the same pyrethroid and organophosphate pesticides that have been shown to cause water and sediment toxicity in urban and agriculture water bodies throughout California, have the potential to affect estuarine habitats. The results establish baseline data in the Santa Maria River estuary to allow evaluation of ecosystem improvement as management initiatives to reduce pesticide runoff are implemented in this watershed. PMID:24464329

  19. Entrepreneurial ecosystems around the world

    E-print Network

    Kumar, Anand R

    2013-01-01

    Entrepreneurship is a vehicle of growth and job creation. America has understood it and benefitted most from following this philosophy. Governments around the world need to build and grow their entrepreneurial ecosystems ...

  20. Geospatial tools for Ecosystem Services

    EPA Science Inventory

    Northeastern lakes provide valuable ecosystem services that benefit residents and visitors and are increasingly important for provisioning of recreational opportunities and amenities. Concurrently, population growth threatens lakes by, for instance, increasing nutrient loads. ...

  1. Learning from California`s QF auction

    SciTech Connect

    Gribik, P.

    1995-04-15

    California`s 1993 qualifying facility (QF) auction dramatically illustrates problems that can be encountered in structuring auctions for electric utility solicitations of supply-side resources from qualifying cogeneration and small power production facilities. In the 1993 California QF auction, three California utilities were to select QFs that would be awarded long-term purchased-power contracts. The auction produced some unexpected outcomes that could potentially cost the utilities and their customers tens of millions of dollars per year. A year after the auction was held, the parties were still attempting to revise contracts, or even rebid a portion of the auction. And all of this effort may come to naught, depending upon what happens now that the Federal Energy Regulatory Commission has struck down the auction process under California`s Biennial Resource Plan Update, claiming that it violates the Public Utility Regulatory Policies Act (PURPA) by using an improper method to calculate avoided costs. A study of the California QF auction illustrates yet again that the devil is in the details. And the stakes will only rise farther as regulators in other states rely more on auctions to open up the electric industry to further competition.

  2. Seasonal changes in larval fish assemblages in a semi-enclosed sea (Gulf of California)

    NASA Astrophysics Data System (ADS)

    Sánchez-Velasco, L.; Lavín, M. F.; Peguero-Icaza, M.; León-Chávez, C. A.; Contreras-Catala, F.; Marinone, S. G.; Gutiérrez-Palacios, I. V.; Godínez, V. M.

    2009-07-01

    The northern Gulf of California (NGC) is characterized by seasonal hydrography and circulation (cyclonic in summer and anticyclonic in winter), by intense tidal mixing in the midriff archipelago region (MAR), and by coastal upwelling on the eastern side from autumn to spring. We examined changes in larval fish assemblages (LFAs) in relation with hydrography and circulation during both phases of the seasonal circulation, as indicators of changes in the pelagic ecosystem. A canonical correspondence analysis defined LFAs ( r>0.70), which were related with: (i) the coastal current on the mainland shelf, (ii) the central eddy and (iii) the MAR. In the early cyclonic phase, when the temperature and stratification were increasing and the coastal current was starting, demersal ( Gobulus crescentalis, Lythrypnus dalli) and mesopelagic species ( Benthosema panamense) dominated the NGC. The highest larval abundance was in the Current LFA area and the lowest in the MAR LFA area. In the mature cyclonic phase, the larval abundance increased in the NGC and species characteristic of eastern boundary current systems such as Opisthonema libertate and Engraulis mordax displaced the demersal species and became dominant, together with B. panamense in the Current LFA area; the latter species dominated in the Eddy LFA area. In the early anticyclonic phase, the direction of the coastal current reversed and the temperature and larval abundance decreased. E. mordax and B. panamense larvae continued dominating the NGC with higher abundance in the MAR than in the Current and Eddy LFA areas. In the mature anticyclonic phase, E. mordax larvae dominated in the Current and the Eddy LFA areas with the highest abundance in the former, while M. productus larvae (an eastern boundary current species) dominated in the Eddy LFA area. Results showed that in the NGC, the dramatically seasonal and predictable hydrographic and circulation features trigger the seasonal spawning of the dominant species. The biological richness of the coastal current area, in both circulation phases, suggested that this area has an important role in the pelagic ecosystem functionality of the NGC.

  3. Process-Based Thinking in Ecosystem Education

    ERIC Educational Resources Information Center

    Jordan, Rebecca C.; Gray, Steven A.; Brooks, Wesley R.; Honwad, Sameer; Hmelo-Silver, Cindy E.

    2013-01-01

    Understanding complex systems such as ecosystems is difficult for young K-12 students, and students' representations of ecosystems are often limited to nebulously defined relationships between macro-level structural components inherent to the ecosystem in focus (rainforest, desert, pond, etc.) instead of generalizing processes across ecosystems

  4. Coastal Ecosystem Curriculum: Food Web

    NSDL National Science Digital Library

    This curriculum focuses on the coastal ecosystem in the Gulf of the Farallones, in the Pacific Ocean near San Francisco Bay. One goal of this curriculum is to teach about the natural connections in this ecosystem and how humans fit into it. Topics include the seasonal upwelling of ocean water, the feeding relationships among organisms in the open water, the sandy beach habitat along the shoreline, and human impacts on this environment, such as the 1984 oil spill from the tanker "Puerto Rican".

  5. Modelling impacts of second generation bioenergy production on Ecosystem Services in Europe

    NASA Astrophysics Data System (ADS)

    Henner, Dagmar N.; Smith, Pete; Davies, Christian; McNamara, Niall P.

    2015-04-01

    Bioenergy crops are an important source of renewable energy and are a possible mechanism to mitigate global climate warming, by replacing fossil fuel energy with higher greenhouse gas emissions. There is, however, uncertainty about the impacts of the growth of bioenergy crops on ecosystem services. This uncertainty is further enhanced by the unpredictable climate change currently going on. The goal of this project is to develop a comprehensive model that covers as many ecosystem services as possible at a Continental level including biodiversity, water, GHG emissions, soil, and cultural services. The distribution and production of second generation energy crops, such as Miscanthus, Short Rotation Coppice (SRC) and Short Rotation Forestry (SRF), is currently being modelled, and ecosystem models will be used to examine the impacts of these crops on ecosystem services. The project builds on models of energy crop production, biodiversity, soil impacts, greenhouse gas emissions and other ecosystem services, and on work undertaken in the UK on the ETI-funded ELUM project (www.elum.ac.uk). In addition, methods like water footprint tools, tourism value maps and ecosystem valuation tools and models (e.g. InVest, TEEB database, GREET LCA Model, World Business Council for Sustainable Development corporate ecosystem valuation, Millennium Ecosystem Assessment and the Ecosystem Services Framework) will be utilised. Research will focus on optimisation of land use change feedbacks on ecosystem services and biodiversity, and weighting of the importance of the individual ecosystem services. Energy crops will be modelled using low, medium and high climate change scenarios for the years between 2015 and 2050. We will present first results for GHG emissions and soil organic carbon change after different land use change scenarios (e.g. arable to Miscanthus, forest to SRF), and with different climate warming scenarios. All this will be complemented by the presentation of a matrix including all the factors and ecosystem services influenced by land use change to bioenergy crop production under different climate change scenarios.

  6. Identifying Phytoplankton Classes In California Reservoirs Using HPLC Pigment Analysis

    NASA Astrophysics Data System (ADS)

    Siddiqui, S.; Peacock, M. B.; Kudela, R. M.; Negrey, K.

    2014-12-01

    Few bodies of water are routinely monitored for phytoplankton composition due to monetary and time constraints, especially the less accessible bodies of water in central and southern California. These lakes and estuaries are important for economic reasons such as tourism and fishing. This project investigated the composition of phytoplankton present using pigment analysis to identify dominant phytoplankton groups. A total of 28 different sites with a wide range of salinity (0 - 60) in central and southern California were examined. These included 13 different bodies of water in central California: 6 in the Sierras, 7 in the San Francisco Bay Estuary, and 15 from southern California. The samples were analyzed using high-performance liquid-chromatography (HPLC) to quantify the pigments present (using retention time and the spectral thumbprint). Diagnostic pigments were used to indicate the phytoplankton class composition, focusing on diatoms, dinoflagellates, cryptophytes, and cyanobacteria - all key phytoplankton groups indicative of the health of the sampled reservoir. Our results indicated that cyanobacteria dominated four of the seven bodies of central California water (Mono Lake, Bridgeport Reservoir, Steamboat Slough, and Pinto Lake); cryptophytes and nannoflagellates dominated two of the central California bodies of water (Mare Island Strait and Topaz Lake); and diatoms and dinoflagellates dominated one central California body of water, Oakland Inner Harbor, comprising more than 70% of the phytoplankton present. We expect the bodies of water from Southern California to be as disparate. Though this data is only a snapshot, it has significant implications in comparing different ecosystems across California, and it has the potential to provide valuable insight into the composition of phytoplankton communities.

  7. Research infrastructure support to address ecosystem dynamics

    NASA Astrophysics Data System (ADS)

    Los, Wouter

    2014-05-01

    Predicting the evolution of ecosystems to climate change or human pressures is a challenge. Even understanding past or current processes is complicated as a result of the many interactions and feedbacks that occur within and between components of the system. This talk will present an example of current research on changes in landscape evolution, hydrology, soil biogeochemical processes, zoological food webs, and plant community succession, and how these affect feedbacks to components of the systems, including the climate system. Multiple observations, experiments, and simulations provide a wealth of data, but not necessarily understanding. Model development on the coupled processes on different spatial and temporal scales is sensitive for variations in data and of parameter change. Fast high performance computing may help to visualize the effect of these changes and the potential stability (and reliability) of the models. This may than allow for iteration between data production and models towards stable models reducing uncertainty and improving the prediction of change. The role of research infrastructures becomes crucial is overcoming barriers for such research. Environmental infrastructures are covering physical site facilities, dedicated instrumentation and e-infrastructure. The LifeWatch infrastructure for biodiversity and ecosystem research will provide services for data integration, analysis and modeling. But it has to cooperate intensively with the other kinds of infrastructures in order to support the iteration between data production and model computation. The cooperation in the ENVRI project (Common operations of environmental research infrastructures) is one of the initiatives to foster such multidisciplinary research.

  8. CALIFORNIA ENERGY EFFECT OF LAND USE CHOICES ON

    E-print Network

    CALIFORNIA ENERGY COMMISSION EFFECT OF LAND USE CHOICES ON TRANSPORTATION FUEL DEMAND IN SUPPORT ................................................................................................................... 1 Current Approach to Transportation Fuel Demand and Land Use Planning........... 1 Obstacles to Efficient Land Use Planning .................................................................. 2 Trends

  9. Resilience to Changing Snow Depth in a Shrubland Ecosystem.

    NASA Astrophysics Data System (ADS)

    Loik, M. E.

    2008-12-01

    Snowfall is the dominant hydrologic input for high elevations and latitudes of the arid- and semi-arid western United States. Sierra Nevada snowpack provides numerous important services for California, but is vulnerable to anthropogenic forcing of the coupled ocean-atmosphere system. GCM and RCM scenarios envision reduced snowpack and earlier melt under a warmer climate, but how will these changes affect soil and plant water relations and ecosystem processes? And, how resilient will this ecosystem be to short- and long-term forcing of snow depth and melt timing? To address these questions, our experiments utilize large- scale, long-term roadside snow fences to manipulate snow depth and melt timing in eastern California, USA. Interannual snow depth averages 1344 mm with a CV of 48% (April 1, 1928-2008). Snow fences altered snow melt timing by up to 18 days in high-snowfall years, and affected short-term soil moisture pulses less in low- than medium- or high-snowfall years. Sublimation in this arid location accounted for about 2 mol m- 2 of water loss from the snowpack in 2005. Plant water potential increased after the ENSO winter of 2005 and stayed relatively constant for the following three years, even after the low snowfall of winter 2007. Over the long-term, changes in snow depth and melt timing have impacted cover or biomass of Achnatherum thurberianum, Elymus elemoides, and Purshia tridentata. Growth of adult conifers (Pinus jeffreyi and Pi. contorta) was not equally sensitive to snow depth. Thus, complex interactions between snow depth, soil water inputs, physiological processes, and population patterns help drive the resilience of this ecosystem to changes in snow depth and melt timing.

  10. Ecosystem carbon dioxide fluxes after disturbance in forests of North America

    NASA Astrophysics Data System (ADS)

    Amiro, B. D.; Barr, A. G.; Barr, J. G.; Black, T. A.; Bracho, R.; Brown, M.; Chen, J.; Clark, K. L.; Davis, K. J.; Desai, A. R.; Dore, S.; Engel, V.; Fuentes, J. D.; Goldstein, A. H.; Goulden, M. L.; Kolb, T. E.; Lavigne, M. B.; Law, B. E.; Margolis, H. A.; Martin, T.; McCaughey, J. H.; Misson, L.; Montes-Helu, M.; Noormets, A.; Randerson, J. T.; Starr, G.; Xiao, J.

    2010-10-01

    Disturbances are important for renewal of North American forests. Here we summarize more than 180 site years of eddy covariance measurements of carbon dioxide flux made at forest chronosequences in North America. The disturbances included stand-replacing fire (Alaska, Arizona, Manitoba, and Saskatchewan) and harvest (British Columbia, Florida, New Brunswick, Oregon, Quebec, Saskatchewan, and Wisconsin) events, insect infestations (gypsy moth, forest tent caterpillar, and mountain pine beetle), Hurricane Wilma, and silvicultural thinning (Arizona, California, and New Brunswick). Net ecosystem production (NEP) showed a carbon loss from all ecosystems following a stand-replacing disturbance, becoming a carbon sink by 20 years for all ecosystems and by 10 years for most. Maximum carbon losses following disturbance (g C m-2y-1) ranged from 1270 in Florida to 200 in boreal ecosystems. Similarly, for forests less than 100 years old, maximum uptake (g C m-2y-1) was 1180 in Florida mangroves and 210 in boreal ecosystems. More temperate forests had intermediate fluxes. Boreal ecosystems were relatively time invariant after 20 years, whereas western ecosystems tended to increase in carbon gain over time. This was driven mostly by gross photosynthetic production (GPP) because total ecosystem respiration (ER) and heterotrophic respiration were relatively invariant with age. GPP/ER was as low as 0.2 immediately following stand-replacing disturbance reaching a constant value of 1.2 after 20 years. NEP following insect defoliations and silvicultural thinning showed lesser changes than stand-replacing events, with decreases in the year of disturbance followed by rapid recovery. NEP decreased in a mangrove ecosystem following Hurricane Wilma because of a decrease in GPP and an increase in ER.

  11. INCREASE PUBLIC AWARENESS OF THE LOWER LAGUNA MADRE, CBB & GALVESTON BAY ECOSYSTEMS MX964490

    EPA Science Inventory

    Texas Parks and Wildlife currently conducts Coastal Expos that educate individuals. The events primarily target minority and urban populations. The Coastal Expos increase public awareness of Texas coastal ecosystems, why they are important and how individuals can protect them t...

  12. USING FISHER INFORMATION TO DETECT GRADUAL AND RAPID ECOSYSTEM REGIME SHIFTS

    EPA Science Inventory

    As ecosystems experience perturbations of varying regularity and intensity, they may either remain within the state space neighborhood of the current regime, or "flip" into the neighborhood of a regime with different characteristics. Although the possibility of such regime shifts...

  13. Improving parameterization of scalar transport through vegetation in a coupled ecosystem-atmosphere model

    E-print Network

    Link, Percy Anne

    2008-01-01

    Several regional-scale ecosystem models currently parameterize subcanopy scalar transport using a rough-wall boundary eddy diffusivity formulation. This formulation predicts unreasonably high soil evaporation beneath tall, ...

  14. Occult precipitation and plants: its consequences for individuals and ecosystems

    NASA Astrophysics Data System (ADS)

    Dawson, T. E.

    2006-12-01

    Fog, dew and cloud water inputs, aptly termed, occult precipitation", are not traditionally quantified yet more than two decades of research has revealed their importance to a wide range of vegetation types. Utilizing stable isotope methods, field and laboratory based physiological measurements, and a suite of occult precipitation collection approaches we now know that plants inhabiting a wide range of ecosystem types from the coastal California redwood forests and grasslands, to the Brazilian Cerrado (savanna), the Chilean community types are utilizing fog, dew and cloud water. Hydrogen and oxygen stable isotope analysis have revealed that both fog drip into the rooting zone and direct foliar-uptake of occult precipitation can occur and in some species, seasons and in drought-prone ecosystems it can easily constitute 30% of the annual hydrological inputs and between 20-60+% of all the water used by the vegetation. Fog and cloud water inputs can also be a significant source of water for re-supplying depleted sub-surface water stores. Perhaps most importantly, this important hydrological input not only helps sustain the physiological integrity of individual plants by allowing root and leaf functions to occur but has a marked impact on the manner and magnitude but which biogeochemical cycling proceeds. I will review the available data that point to the importance of quantifying occult precipitation inputs and then discuss its consequences for both individual plants and the entire ecosystems then compose. The data suggest that such information can now be incorporated into hydrological budgets and biogeochemical models.

  15. New observations of VOC emissions and concentrations in, above, and around the Central Valley of California

    NASA Astrophysics Data System (ADS)

    Goldstein, A. H.; Fares, S.; Gentner, D. R.; Park, J.; Weber, R.; Ormeno, E.; Holzinger, R.; Misztal, P. K.; Karl, T. R.; Guenther, A. B.; Fischer, M. L.; Harley, R. A.; Karlik, J. F.

    2011-12-01

    Large portions of the Central Valley of California are out of compliance with current state and federal air quality standards for ozone and particulate matter, and the relative importance of biogenic and anthropogenic VOC emissions to their photochemical production in this region remains uncertain. In 2009-2011 multiple measurement campaigns were completed investigating the VOC emission inventory and concentration distributions. In 2009 BVOC emissions from more than 20 species of major agricultural crops in California were measured in a greenhouse using branch enclosures by both PTRMS and in-situ GC. Overall, crops were found to emit low amounts of BVOC compared to the natural forests surrounding the valley. Crops mainly emitted methanol and terpenes, with a broad array of other species emitted at lower levels, and all the measured crops showed negligible emissions of isoprene. Navel oranges were the largest crop BVOC emitters measured so a full year of flux measurements were made in an orange grove near Visalia in 2010 by eddy covariance(EC)-PTRMS with two multi-week periods of concentration measurements by hourly in-situ GC, and one month of high mass resolution flux measurements by EC-PTR-TOF-MS. The dominant BVOC emissions from the orange grove were methanol and terpenes, followed by acetone, acetaldehyde, and a low level of emissions for many other species. In 2011 aircraft eddy covariance measurements of BVOC fluxes were made by EC-PTRMS covering a large area of California as part of the California Airborne Bvoc Emission Research in Natural Ecosystem Transects (CABERNET) campaign aimed at improving BVOC emission models on regional scales, mainly profiling BVOC emissions from oak woodlands surrounding the Central Valley. In 2010, hourly in-situ VOC measurements were made via in-situ GC in Bakersfield, CA as part of the CalNex experiment. Additionally, in-situ measurements of fresh motor vehicle exhaust were made in Oakland's Caldecott tunnel. Measurements by in-situ GC included more than 200 anthropogenic and biogenic VOCs with a wide range of volatilities (up to 17 carbon atoms in size) and various functional groups (e.g. aldehydes, ketones, alcohols, halogens, sulfur, & nitrogen). Finally, in 2011 vertical profiles of VOC were made at 5 heights on a communication tower at Walnut Grove (~20 miles south of Sacramento) from 30' to 1550' by PTRMS. Results from all of these studies combined provide a novel overview of the distribution of VOC emissions and concentrations in, around, and above the Central Valley of California.

  16. Bacterial 5'-nucleotidase in Aquatic Ecosystems: A Novel Mechanism of Phosphorus Regeneration

    Microsoft Academic Search

    James W. Ammerman; Farooq Azam

    1985-01-01

    Zooplankton excretion and algal alkaline phosphatase are presumed to be responsible for phosphorus recycling in aquatic ecosystems; the role of bacteria has been unclear. High levels of bacterial cell-surface 5'-nucleotidase were discovered in samples of picoplankton from California coastal waters. 5'-Nucleotidase rapidly generated orthophosphate from 5'-nucleotide added in nanomolar amounts and could supply half the orthophosphate required by plankton. Unlike

  17. Curriculum Development in Remote Sensing at California State University, Monterery, Seaside, California 93955

    NASA Technical Reports Server (NTRS)

    Sinha, Ravi; Geol, P.

    1996-01-01

    The NASA-Ames Research Center and the California State University, Monterey Bay, California (CSUMB), have signed a Memorandum of Understanding (MOU) to develop and provide cooperative programs between the Ecosystem Science and Technology Branch of NASA (ECOSAT) and the University (CSUMB). The agreement is to carry out educational, research, and technology goals in ecological and environmental sciences and related disciplines, with particular emphasis on changing environmental and climatic conditions occurring worldwide due to the anthropogenic causes affecting the balance within ecological systems and the health and well-being of humans. The preparation of the Curriculum for Remote Sensing at CSUMB was undertaken at the request of the Center as a result of the above agreement.

  18. Avian ecosystem functions are influenced by small mammal ecosystem engineering

    PubMed Central

    2013-01-01

    Background Birds are important mobile link species that contribute to landscape-scale patterns by means of pollination, seed dispersal, and predation. Birds are often associated with habitats modified by small mammal ecosystem engineers. We investigated whether birds prefer to forage on degu (Octodon degus) runways by comparing their foraging effort across sites with a range of runway densities, including sites without runways. We measured granivory by granivorous and omnivorous birds at Rinconada de Maipú, central Chile. As a measure of potential bird foraging on insects, we sampled invertebrate prey richness and abundance across the same sites. We then quantified an index of plot-scale functional diversity due to avian foraging at the patch scale. Results We recorded that birds found food sources sooner and ate more at sites with higher densities of degu runways, cururo mounds, trees, and fewer shrubs. These sites also had higher invertebrate prey richness but lower invertebrate prey abundance. This implies that omnivorous birds, and possibly insectivorous birds, forage for invertebrates in the same plots with high degu runway densities where granivory takes place. In an exploratory analysis we also found that plot-scale functional diversity for four avian ecosystem functions were moderately to weakly correllated to expected ecosystem function outcomes at the plot scale. Conclusions Degu ecosystem engineering affects the behavior of avian mobile link species and is thus correlated with ecosystem functioning at relatively small spatial scales. PMID:24359802

  19. Carbon Dioxide and Water Vapor Fluxes at Reduced and Elevated CO2 Concentrations in Southern California Chaparral

    NASA Astrophysics Data System (ADS)

    Cheng, Y.; Oechel, W. C.; Hastings, S. J.; Bryant, P. J.; Qian, Y.

    2003-12-01

    This research took two different approaches to measuring carbon and water vapor fluxes at the plot level (2 x 2 meter and 1 x 1 meter plots) to help understand and predict ecosystem responses to elevated CO2 concentrations and concomitant environmental changes. The first measurement approach utilized a CO2-controlled, ambient lit, temperature controlled (CO2LT) null-balance chamber system run in a chaparral ecosystem in southern California, with six different CO2 concentrations ranging from 250 to 750 ppm CO2 concentrations with 100 ppm difference between treatments. The second measurement approach used a free air CO2 enrichment (FACE) system operated at 550 ppm CO2 concentration. These manipulations allowed the study of responses of naturally-growing chaparral to varying levels of CO2, under both chamber and open air conditions. There was a statistically significant CO2 effect on annual NEE (net ecosystem exchange) during the period of this study, 1997 to 2000. The effects of elevated CO2 on CO2 and water vapor flux showed strong seasonal patterns. Elevated CO2 delayed the development of water stress, enhanced leaf-level photosynthesis, and decreased transpiration and conductance rates. These effects were observed regardless of water availability. Ecosystem CO2 sink strength and plant water status were significantly enhanced by elevated CO2 when water availability was restricted. Comparing the FACE treatment and the FACE control, the ecosystem was either a stronger sink or a weaker source to the atmosphere throughout the dry seasons, but there was no statistically significant difference during the wet seasons. Annual average leaf transpiration decreased with the increasing of the atmospheric CO2 concentration. Although leaf level water-use efficiency (WUE) increased with the growth CO2 concentration increase, annual evapotranspiration (ET) during these four years also increased with the increase of the atmospheric CO2 concentrations. These results indicate that chaparral or other similar ecosystems, under future elevated CO2 concentrations, might be even more water stressed than they are under current conditions.

  20. Grays Lake Ecosystem

    NSDL National Science Digital Library

    The Northern Prairie Wildlife Research Center (NPWRC) has posted several new (or newly online) resources on wetlands and birds. This resource, from the US Geological Survey, focuses on the Grays Lake National Wildlife Refuge, and current and previous research conducted there on bird and plant species.