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Networks have become a central concept in the policy and public management literature; however, theoretical development is hindered by a lack of attention to the empirical properties of network measurement methods. This paper compares three survey-based methods for measuring organizational networks: the roster, the free-recall name generator, and a hybrid name generator that combines these two classic approaches. Results indicate that the roster and free-recall name generator methods both suffer from important limitations. The roster method tends to measure many linkages among a limited set of network actors, whereas the name generator tends to measure fewer linkages among a larger set of network actors. Using survey data on policy networks within California regional planning processes (N = 752), we find that the hybrid method strikes an effective balance between these techniques. The hybrid approach performs well in terms of identifying a large number of network actors and interconnections between them. Although no survey-based measurement technique is perfect, this study suggests that the hybrid name generator is an excellent alternative for the measurement of complex networks with large or shifting boundaries that encompass a diverse set of actors. (Contains 8 footnotes, 4 tables, and 2 figures.)

Networks have become a central concept in the policy and public management literature; however, theoretical development is hindered by a lack of attention to the empirical properties of network measurement methods. This paper compares three survey-based methods for measuring organizational networks: the roster, the free-recall name generator, and a hybrid name generator that combines these two classic approaches. Results indicate that the roster and free-recall name generator methods both suffer from important limitations. The roster method tends to measure many linkages among a limited set of network actors, whereas the name generator tends to measure fewer linkages among a larger set of network actors. Using survey data on policy networks within California regional planning processes ( N = 752), we find that the hybrid method strikes an effective balance between these techniques. The hybrid approach performs well in terms of identifying a large number of network actors and interconnections between them. Although no survey-based measurement technique is perfect, this study suggests that the hybrid name generator is an excellent alternative for the measurement of complex networks with large or shifting boundaries that encompass a diverse set of actors. [ABSTRACT FROM AUTHOR]

Landscape connectivity is vital to the ecological health of many landscapes, and identification of linkages in working landscapes that are somewhat, but not irreversibly, degraded is needed. Assessment of the current ecological condition of habitat linkages can be used to determine appropriate management activities, including restoration. Forecasting the future ecological condition of identified linkages under multiple human-use scenarios can identify future patterns of vulnerability and degradation, and thus aid in prioritization of conservation and restoration actions. We forecast the ecological condition of a modeled conservation network of cores and habitat linkages in the San Joaquin Valley, California, a highly developed agricultural area. We assessed current and projected future impacts from modeled urban growth representing seven regional urban growth policy scenarios to determine conservation and restoration priorities. We characterized current ecological condition of the linkages using a clustering algorithm that compared vegetation type, length, and major road and canal crossings. The modeled urban growth forecasts were overlaid on the ecological network to identify expected impacts. A threat index was calculated for individual network components and for component clusters, and revealed significant impact differences between the various urban growth scenarios. The linkages most threatened by urban conversion were those that are currently the most ecologically degraded, suggesting that a significant future conservation issue in this working landscape will be the loss of restoration opportunities rather than loss of intact wildlife linkages. This study presents an approach for incorporating regional conservation design with urban growth policy analysis for working landscapes. [ABSTRACT FROM AUTHOR]

The article examines the roles of policy-relevant beliefs and social capital as drivers of network structure with reference to regional planning in California. The theories of social capital focus on how cooperation is supported by norms of reciprocity and civic engagement. Testing the importance of network configurations needs statistical techniques, which take into account the interdependent nature of network relationships. Belief stability and policy relevance have an interactive effect on policy network structure.

Fresno County is a rich agricultural area that faces rapid urbanization and farmland conversion. The county is participating in a strategic, multicounty planning initiative aimed at making sustainable and regionally cohesive land-use decisions. To inform this effort, we conducted a farmland conservation assessment and identified strategic farmlands for prioritization in future conservation efforts. We identified environmental and human predictor variables that affect the viability of existing farmland, used a geographic information system (GIS) to integrate them, and created a countywide strategic farmland conservation map. We compared our analysis to status quo methods of prioritization and found that with our model the spatial output of highly valued farmland was shifted, narrowed and located adjacent to some of the county's most urbanized areas. These findings are influencing growth policies and farmland conservation planning in Fresno County. [ABSTRACT FROM AUTHOR]

This study presents a GIS-based database framework used to assess aggregate terrestrial habitat impacts from multiple highway construction projects in California, USA. Transportation planners need such impact assessment tools to effectively address additive biological mitigation obligations. Such assessments can reduce costly delays due to protracted environmental review. This project incorporated the best available statewide natural resource data into early project planning and preliminary environmental assessments for single and multiple highway construction projects, and provides an assessment of the 10-year state-wide mitigation obligations for the California Department of Transportation. Incorporation of these assessments will facilitate early and more strategic identification of mitigation opportunities, for single-project and regional mitigation efforts. The data architecture format uses eight spatial scales: six nested watersheds, counties, and transportation planning districts, which were intersected. This resulted in 8058 map planning units statewide, which were used to summarize all subsequent analyses. Range maps and georeferenced locations of federally and state-listed plants and animals and a 55-class landcover map were spatially intersected with the planning units and the buffered spatial footprint of 967 funded projects. Projected impacts were summarized and output to the database. Queries written in the database can sum expected impacts and provide summaries by individual construction project, or by watershed, county, transportation district or highway. The data architecture allows easy incorporation of new information and results in a tool usable without GIS by a wide variety of agency biologists and planners. The data architecture format would be useful for other types of regional planning. [ABSTRACT FROM AUTHOR]

Investigates the phytoplankton composition of algal toxins in the Salton Sea in California. Attainment of high densities of in nearshore areas during the summer and spring; Presence of dense algal blooms in the area; Role of the blooms of phytoplankton cells to the mortality of wildlife in the area.

Reports on blooms of Pleurochrysis pseudoroscoffensis observed in the Salton Sea, California and on assessments of their pigment composition and toxicity. Observation of small numbers of a coccolithophorid during a plankton survey of the lake in 1955-1956; Collection and preservation of phytoplankton.

Government agencies that develop infrastructure such as roads, waterworks, and energy delivery often impact natural ecosystems, but they also have unique opportunities to contribute to the conservation of regional natural resources through compensatory mitigation. Infrastructure development requires a planning, funding, and implementation cycle that can frequently take a decade or longer, but biological mitigation is often planned and implemented late in this process, in a project-by-project piecemeal manner. By adopting early regional mitigation needs assessment and planning for habitat-level impacts from multiple infrastructure projects, agencies could secure time needed to proactively integrate these obligations into regional conservation objectives. Such practice can be financially and ecologically beneficial due to economies of scale, and because earlier mitigation implementation means potentially developable critical parcels may still be available for conservation. Here, we compare the integration of regional conservation designs, termed greenprints, with early multi-project mitigation assessment for two areas in California, USA. The expected spatial extent of habitat impacts and associated mitigation requirements from multiple projects were identified for each area. We used the reserve-selection algorithm MARXAN to identify a regional greenprint for each site and to seek mitigation solutions through parcel acquisition that would contribute to the greenprint, as well as meet agency obligations. The two areas differed in the amount of input data available, the types of conservation objectives identified, and local land-management capacity. They are representative of the range of conditions that conservation practitioners may encounter, so contrasting the two illustrates how regional advanced mitigation can be generalized for use in a wide variety of settings. Environmental organizations can benefit from this approach because it provides a platform for collaboration with infrastructure agencies. Alone, infrastructure agency mitigation obligations will not satisfy all greenprint objectives, but they can be a major contributor to the ongoing process of implementing ecologically sustainable regional plans. [ABSTRACT FROM AUTHOR]