History of wildland fires on Vandenberg Air Force Base, California

The fire history of the past 50 years for Vandenberg AFB, California was determined using aerial photography, field investigation, and historical and current written records. This constitutes a record of the vegetation age classes for the entire base. The location, cause, and fuel type for sixty fires from this time period were determined. The fires were mapped and entered into a geographic infomation system (GIS) for Vandenberg. Fire history maps derived from this GIS were printed at 1:9600 scale and are on deposit at the Vandenberg Environmental Task Force Office. Although some ecologically significant plant communities on Vandenberg are adapted to fire, no natural fire frequency could be determined, since only one fire possibly caused by lightning occurred in the area now within the base since 1937. Observations made during this study suggest that burning may encourage the invasion of exotic species into chaparral, in particular Burton Mesa or sandhill chaparral, an unusual and geographically limited form of chaparral found on the base

Oklahoma

In Naylor Farms, Inc. v. Chaparral Energy, LLC, the plaintiff royalty owners (collectively, Naylor Farms) contended that Chaparral systematically underpaid royalties on production from approximately 2,500 Oklahoma oil and gas wells by improperly deducting from royalty payments certain costs that the plaintiffs contended should have been borne solely by Chaparral under Oklahoma law. The district court granted Naylor Farms’ motion seeking certification of a class of royalty owners under Rule 23 of the Federal Rules of Civil Procedure. In the present proceedings, Chaparral has appealed the district court’s order granting class certification

Sediment Management for Southern California Mountians, Coastal Plains and Shoreline. Part D: Special Inland Studies

In southern California the natural environmental system involves the continual relocation of sedimentary materials. Particles are eroded from inland areas where there is sufficient relief and, precipitation. Then, with reductions in hydraulic gradient along the stream course and at the shoreline, the velocity of surface runoff is reduced and there is deposition. Generally, coarse sand, gravel and larger particles are deposited near the base of the eroding surfaces (mountains and hills) and the finer sediments are deposited on floodplains, in bays or lagoons, and at the shoreline as delta deposits. Very fine silt and clay particles, which make up a significant part of the eroded material, are carried offshore where they eventually deposit in deeper areas. Sand deposited at the shoreline is gradually moved along the coast by waves and currents, and provides nourishment for local beaches. However, eventually much of this littoral material is also lost to offshore areas. Human developments in the coastal region have substantially altered the natural sedimentary processes, through changes in land use, the harvesting of natural resources (logging, grazing, and sand and gravel mining); the construction and operation of water conservation facilities and flood control structures; and coastal developments. In almost all cases these developments have grown out of recognized needs and have well served their primary purpose. At the time possible deleterious effects on the local or regional sediment balance were generally unforeseen or were felt to be of secondary importance. In 1975 a large-scale study of inland and coastal sedimentation processes in southern California was initiated by the Environmental Quality Laboratory at the California Institute of Technology and the Center for Coastal Studies at Scripps Institution of Oceanography. This volume is one of a series of reports from this study. Using existing data bases, this series attempts to define quantitatively inland and coastal sedimentation processes and identify the effects man has had on these processes. To resolve some issues related to long-term sediment management, additional research and data will be needed. In the series there are four Caltech reports that provide supporting studies for the summary report (EQL Report No. 17). These reports include: EQL Report 17-A Regional Geological History EQL Report 17-B Inland Sediment Movements by Natural Processes EQL Report 17-C Coastal Sediment Delivery by Major Rivers in Southern California EQL Report 17-D -- Special Inland Studies Additional supporting reports on coastal studies (shoreline sedimentation processes, control structures, dredging, etc.) are being published by the Center for Coastal Studies at Scripps Institution of Oceanography, La Jolla, California

Plant hydraulic traits reveal islands as refugia from worsening drought.

Relatively mesic environments within arid regions may be important conservation targets as 'climate change refugia' for species persistence in the face of worsening drought conditions. Semi-arid southern California and the relatively mesic environments of California's Channel Islands provide a model system for examining drought responses of plants in potential climate change refugia. Most methods for detecting refugia are focused on 'exposure' of organisms to certain abiotic conditions, which fail to assess how local adaptation or acclimation of plant traits (i.e. 'sensitivity') contribute to or offset the benefits of reduced exposure. Here, we use a comparative plant hydraulics approach to characterize the vulnerability of plants to drought, providing a framework for identifying the locations and trait patterns that underlie functioning climate change refugia. Seasonal water relations, xylem hydraulic traits and remotely sensed vegetation indices of matched island and mainland field sites were used to compare the response of native plants from contrasting island and mainland sites to hotter droughts in the early 21st century. Island plants experienced more favorable water relations and resilience to recent drought. However, island plants displayed low plasticity/adaptation of hydraulic traits to local conditions, which indicates that relatively conserved traits of island plants underlie greater hydraulic safety and localized buffering from regional drought conditions. Our results provide an explanation for how California's Channel Islands function as a regional climate refugia during past and current climate change and demonstrate a physiology-based approach for detecting potential climate change refugia in other systems

Community Structure and Differential Mortality of Chaparral during Extreme Drought

We have set out to find, in extreme drought, which species of chaparral are dominant and why they are dominating. We thought that the indicator species of chaparral, Adenostoma fasciculatum, would have highest relative density, relative frequency, and dominance in our research area. Additionally, plants with higher water potential values would have lower percentages of mortality. Chaparral with stronger ability to fluoresce (higher Fv/Fm value) would have lower mortality percentages due to their ability to dissipate excess energy, and therefore reduce water loss. By analyzing our vegetation area using point-quarter sampling system, we were able to record data that show the chaparral shrub with the highest relative density was A. fasciculatum. The chaparral shrub with the highest relative dominance was Adenostoma sparsifolium. The chaparral shrub with the highest relative frequency was Ceanothus cuneatus. Midday water potential values were taken using the Scholander-Hammel Pressure Chamber from the sample site and plotted against the other plants. Arctostaphylos glauca had the lowest water potential (-13.6 MPa) while Malosma laurina had the highest water potential (-3.7MPa). Except for the outlier, Ceanothus spinosus, midday water potentials corresponded negatively to mortality. Fluorescence values and water potential values were positively correlated (R2= 0.7466). Water potential values are positively correlated with chaparral shrub mortality (R2=0.566). Fluorescence also links with chaparral shrub mortality (R2= 0.845)

Art Neural Networks for Remote Sensing: Vegetation Classification from Landsat TM and Terrain Data

A new methodology for automatic mapping from Landsat Thematic Mapper (TM) and terrain data, based on the fuzzy ARTMAP neural network, is developed. System capabilities are tested on a challenging remote sensing classification problem, using spectral and terrain features for vegetation classification in the Cleveland National Forest. After training at the pixel level, system performance is tested at the stand level, using sites not seen during training. Results are compared to those of maximum likelihood classifiers, as well as back propagation neural networks and K Nearest Neighbor algorithms. ARTMAP dynamics are fast, stable, and scalable, overcoming common limitations of back propagation, which did not give satisfactory performance. Best results are obtained using a hybrid system based on a convex combination of fuzzy ARTMAP and maximum likelihood predictions. A prototype remote sensing example introduces each aspect of data processing and fuzzy ARTMAP classification. The example shows how the network automatically constructs a minimal number of recognition categories to meet accuracy criteria. A voting strategy improves prediction and assigns confidence estimates by training the system several times on different orderings of an input set.National Science Foundation (IRI 94-01659, SBR 93-00633); Office of Naval Research (N00014-95-l-0409, N00014-95-0657

The Response of Zigadenus fremontii to Variation in Fire Regime

California\u27s chaparral shrub communities are naturally exposed to dry-season fire. It could be reasoned that prescription burns set during the wet season by land managers would have more detrimental effects on plant regeneration than dry season fires because wet season burns are more likely to kill newly emergent seedlings and damage newly emerged leaves of mature plants. Six field sites with flowering Zigadenus fremontii, an herbaceous perennial geophyte common to chapparal and part of the post-fire bloom, were established at Henry W. Coe State Park in Nothern California. Three sites were part of the September 2007 Lick Wildfire and three were part of a February 2007 prescription burn. The sites were monitored for Z. fremontii regeneration over two years. Z. fremontii exposed to the prescription burn fared better than the wildfire plants, with inflorescence height being significantly higher in prescribed burn sites. Bulbs were transplanted into soil from the prescription burn, wildfire, and unburned area to determine differences in regeneration due to soil characteristics. There were no significant differences due to soil types, but only bulbs from the prescription burn sites had the ability to produce flowers in multiple years subsequent to fire. Differences in germination rates between seeds grown in soil from the wildfire, prescription burn, and unburned soil were investigated via a controlled germination experiment. There was a trend for increased germination in burned soils compared to unburned soils. The evidence from this study suggests that geophytes can benefit from fires set outside of the natural fire season of chaparral

A Neural Network Method for Efficient Vegetation Mapping

This paper describes the application of a neural network method designed to improve the efficiency of map production from remote sensing data. Specifically, the ARTMAP neural network produces vegetation maps of the Sierra National Forest, in Northern California, using Landsat Thematic Mapper (TM) data. In addition to spectral values, the data set includes terrain and location information for each pixel. The maps produced by ARTMAP are of comparable accuracy to maps produced by a currently used method, which requires expert knowledge of the area as well as extensive manual editing. In fact, once field observations of vegetation classes had been collected for selected sites, ARTMAP took only a few hours to accomplish a mapping task that had previously taken many months. The ARTMAP network features fast on-line learning, so the system can be updated incrementally when new field observations arrive, without the need for retraining on the entire data set. In addition to maps that identify lifeform and Calveg species, ARTMAP produces confidence maps, which indicate where errors are most likely to occur and which can, therefore, be used to guide map editing

Reconstructed Dynamics of Rapid Extinctions of Chaparral-Requiring Birds in Urban Habitat Islands

The distribution of native, chaparral-requiring bird species was determined for 37 isolated fragments of canyon habitat ranging in size from 0.4 to 104 hectares in coastal, urban San Diego County, California The area of chaparral habitat and canyon age (time since isolation of the habitat fragment) explains most of the variation in the number of chaparral-requiring bird species. In addition, the distribution of native predators may influence species number. There is statistical evidence that coyotes control the populations of smaller predators such as foxes and domestic cats. The absence of coyotes may lead to higher levels of predation by a process of mesopredator release. The distance of canyons from other patches of chaparral habitat does not add significantly to the explained variance in chaparral-requiring species number–probably because of the virtual inability of most chaparral-requiring species to disperse through developed areas and nonscrub habitats. These results and other lines of evidence suggest that chaparral-requiring birds in isolated canyons have very high rates of extinction, in part because of their low vagility. The best predictors of vulnerability of the individual species are their abundances (densities) in undisturbed habitat and their body sizes; together these two variables account for 95 percent of the variation in canyon occupancy. A hypothesis is proposed to account for the similarity between the steep slopes of species-area curves for chaparral-requiring birds and the slopes for some forest birds on small islands or in habitat fragments. The provision of corridors appears to be the most effective design and planning feature for preventing the elimination of chaparral-requiring species in a fragmented landscape.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74761/1/j.1523-1739.1988.tb00337.x.pd