Species In California Research Articles

Histopathologic Effect of Persea americana Aqueous Leaves Extract on the Liver and Kidney of Weaner Rabbits (California Species)

La Persea americana (aguacate o palta) crece ampliamente en algunas partes del sudeste de Nigeria y se utiliza como planta medicinal en el tratamiento de varias dolencias por profesionales de la medicina alternativa, pero muy poca investigacion se ha llevado a cabo en relacion a su toxicidad farmacologica. Este estudio tiene el objetivo de estudiar el efecto histopatologico del extracto acuoso de hojas de Persea americana sobre el higado y rinones de conejos. Hojas frescas de Persea americana fueron procesadas mediante extraccion con Soxhlet para obtener el extracto acuoso. Tres grupos de conejos destetados denominados control, dosis recomendada y dosis alta se les dio agua con 75mg/kg/dia y 150mg/kg/dia del extracto respectivamente durante 28 dias. Los animales fueron sacrificados. Los higados y rinones fueron recolectados y fijados al 10% en formol tamponado y luego procesados en parafina. Se tineron cortes de 5µm por los metodos de Hematoxilina-Eosina y de Perl (azul de Prusia). Un aumento ligeramente mayor de peso en los grupos experimentales sugiere que el extracto aumenta el apetito de los animales. La histopatologia del higado y rinon en los grupos dosis recomendada y dosis alta no fueron diferentes al grupo control, sugiriendo que el extracto de la planta es beneficioso, excepto por el informe de heces acuosas.

Seasonal timing of first rain storms affects rare plant population dynamics

A major challenge in forecasting the ecological consequences of climate change is understanding the relative importance of changes to mean conditions vs. changes to discrete climatic events, such as storms, frosts, or droughts. Here we show that the first major storm of the growing season strongly influences the population dynamics of three rare and endangered annual plant species in a coastal California (USA) ecosystem. In a field experiment we used moisture barriers and water addition to manipulate the timing and temperature associated with first major rains of the season. The three focal species showed two- to fivefold variation in per capita population growth rates between the different storm treatments, comparable to variation found in a prior experiment imposing eightfold differences in season-long precipitation. Variation in germination was a major demographic driver of how two of three species responded to the first rains. For one of these species, the timing of the storm was the most critical determinant of its germination, while the other showed enhanced germination with colder storm temperatures. The role of temperature was further supported by laboratory trials showing enhanced germination in cooler treatments. Our work suggests that, because of species-specific cues for demographic transitions such as germination, changes to discrete climate events may be as, if not more, important than changes to season-long variables.

Origins of Olivella Beads in the Coachella Valley, Alta California

It is generally accepted that most <i>Olivella</i> beads recovered from archaeological sites in southern California were manufactured by coastal groups such as the Chumash and the Gabrielino. However, archaeologists working in this region are also aware that some beads that circulated through southern California's prehistoric exchange networks were produced by groups other than those from the coast. The origins of such beads are largely unknown, as very few studies have identified bead production loci away from coastal territories. In this article, I present findings from the analyses of bead collections from several sites in the Coachella Valley, which confirm the presence of <i>Olivella</i> beads made from both Pacific coast and Gulf of California species, and I provide evidence for possible small-scale production of beads in this area in the form of unmodified shell, shell detritus, and beads in production.

Reconsideration of the Taxonomic Status of Mason's Lilaeopsis – A State-Protected Rare Species in California

Lilaeopsis masonii is a California state-listed rare species with a wide range of morphologies observed in the field throughout its range, and in herbaria collections. This extensive variation confounds reliable taxonomic identification, particularly for those specimens intermediate between L. masonii and its sister taxon, L. occidentalis. To investigate the genetic basis of this morphological variation, we examined two portions of the Lilaeopsis genome in seven species. Specifically we sought to determine whether L. masonii is sufficiently distinct from its closely related, widespread congener to continue to warrant specific status. DNA sequence analysis of ITS1, 5.8S, and ITS2 nuclear ribosomal DNA revealed no differences between L. occidentalis and L. masonii California collections, and minimal differences between these samples and L. occidentalis collected from the state of Washington, suggesting strongly that these two species form a single clade. A combination of fragment data from three AFLP primers yielded 274 fragments from 29 samples. Genetic Manhattan distance values calculated from the AFLP matrix within species ranged from a low of 1.4 to a high of 6.6, reflecting minor differences among all samples. UPGMA cluster phenograms support the results of the PCA analysis, illustrating a cluster of L. occidentalis masonii samples distinct from other Lilaeopsis species. Because conservation dollars should protect unique evolutionary entities, we suggest that L. masonii be subsumed under L. occidentalis and therefore no longer receive formal state protection.

Biogenic emissions from Citrus species in California

Biogenic Volatile Organic Compounds (BVOC) emitted from plants are the dominant source of reduced carbon chemicals to the atmosphere and are important precursors to the photochemical production of ozone and secondary organic aerosols. Considering the extensive land used for agriculture, cultivated Citrus plantations may play an important role in the chemistry of the atmosphere especially in regions such as the Central Valley of California. Moreover, the BVOC emissions from Citrus species have not been characterized in detail and more species-specific inputs for regional models of BVOC emissions are needed. In this study, we measured the physiological parameters and emissions of the most relevant BVOC (oxygenated compounds, monoterpenes, and sesquiterpenes) for four predominant Citrus species planted in California (Citrus sinensis var. ‘Parent Navel’, Citrus limon var. ‘Meyer’, Citrus reticulata var. ‘W. Murcott’ and ‘Clementine’). We used two analytical techniques to measure a full range of BVOC emitted: Proton Transfer Reaction Mass Spectrometry (PTR-MS) and gas chromatography with mass spectrometry. Methanol, followed by acetone and acetaldehyde, were the dominant BVOC emitted from lemon and mandarin trees (basal emission rates up to 300 ng(C) g(DW)

The Liriomyza (Agromyzidae: Schizophora: Diptera) of California

The Californian species of Liriomyza Mik are revised, including descriptions, illustrations, photographs and a key to species. Sixty-three species are now known to occur in the state, 12 of which are described here as new: L. bispinula, L. conclavis, L. cunicularia, L. merga, L. miserabilis, L. nebulosa, L. parabella, L. phyllodes, L. projecta, L. salpingion, L. tricornis and L. trixivora. Liriomyza virginica Spencer is included as a junior synonym of L. helianthi Spencer, and L. similis Spencer is included as a synonym of L. artemisiae Spencer. Two species are newly recorded in the United States: L. equiseti Meijere, previously known from Canada and Europe, and L. montana Sehgal, previously known from Canada. A number of specimens of L. brassicae (Riley) have been identified as potential new host “races” or species. Morphological characters are provided to diagnose the sister species L. huidobrensis (Blanchard) and L. langei Frick, previously recognizable only on the basis of molecular data. Numerous new state, county and host records are also presented, and hosts are compared for five of the most common North American agricultural pests: L. brassicae, L. huidobrensis, L. langei, L. sativae Blanchard and L. trifolii (Burgess). California contains the highest diversity of Liriomyza known to occur in North America, containing approximately 70% of all described species known from the lower 48 states.

Implications of newly-formed seed-dispersal mutualisms between birds and introduced plants in northern California, USA

I examined the role of bird dispersal in invasiveness of three non-native plant species in California, USA: Triadica sebifera, Ligustrum lucidum, and Olea europaea. I selected these species because their invasiveness in California is uncertain, but a survey of ornithologists highlighted them as likely bird-dispersed. I quantified bird frugivory of these plants, compared them with a native species (Heteromeles arbutifolia), and explored the management implications of dispersal mutualisms for these and other incipient invasive plants. Fruit removal by birds was sufficient to permit spread for all study species. Seed dispersers (rather than seed predators) and pulse feeders (flocking species with potential for long distance dispersal) performed most fruit removal for the non-native species, a pattern indicative of an effective dispersal regime. The number of fruiting trees per stand was a significant predictor of bird visitation. Founding population size may thus be important in management of invasive, bird-dispersed plants. Disperser-defined niches were relatively narrow because a few disperser species performed the majority of fruit removal from study trees, but each fruit species was consumed by a variety of potential dispersers. This results in strong pairwise niche overlap between some plant species. Ordinated by bird use, study site-species combinations clustered more by geographic location than by plant species, emphasizing the opportunistic nature of bird foraging. None of the non-native focal plant species appears dispersal limited, and all have formed novel mutualisms in California. It is possible that these plants are now in lag phases preceding bird-mediated invasion. Consideration of bird dispersal when evaluating invasiveness is therefore an imperative.

Changes in Climatic Water Balance Drive Downhill Shifts in Plant Species’ Optimum Elevations

Uphill shifts of species' distributions in response to historical warming are well documented, which leads to widespread expectations of continued uphill shifts under future warming. Conversely, downhill shifts are often considered anomalous and unrelated to climate change. By comparing the altitudinal distributions of 64 plant species between the 1930s and the present day within California, we show that climate changes have resulted in a significant downward shift in species' optimum elevations. This downhill shift is counter to what would be expected given 20th-century warming but is readily explained by species' niche tracking of regional changes in climatic water balance rather than temperature. Similar downhill shifts can be expected to occur where future climate change scenarios project increases in water availability that outpace evaporative demand.

Developing a Sustainable Phytomanagement Strategy for Excessive Selenium in Western United States and India

Phytomanagement technology is recognized as an inexpensive and environmental friendly strategy for managing natural-occurring selenium (Se) in soils and in poor quality waters. Multi-year field and greenhouse studies were conducted with different plant species in California, USA and Punjab, India under high Se growing conditions. Some of the plant species included; canola (Brassica napus), mustard (B. juncea), broccoli (B. oleracea), spearmint (Mentha viridis), sugarcane (Saccharum officcinarum), guar (Cyamopsis tetragonoloba), wheat (Triticum aestivum), and poplar (Populus deltoides). California soils had a sodium-sulfate-dominated salinity between 6–10 dS m−1, while Indian soils had a calcium carbonate salinity less than 1 dS m−1. Results demonstrated that high sulfate conditions reduced plant Se accumulation more than 100× in Californian grown plants compared to Se accumulation in Indian grown plants. Tissue concentrations generally did not exceed 10 and 200 mg kg DM−1 in leaves of plants grown in California and India, respectively. At these plant concentrations, Se phytomanagement is more effective in Indian soils than in California soils. Successful management of Se by plants requires selecting crops or crop rotations that are tolerant of the soil condition and identifying and creating new viable Se-enriched products.

The fog of war: Why the environmental crusade for anadromous fish species in California could disarm the State’s local vector control districts in their war against mosquitoes

In California, local mosquito and vector control districts have successfully controlled mosquito and vector-borne diseases by improving drainage patterns and applying pesticides. The Bay-Delta Conservation Plan, which is a proposed habitat conservation plan for the Sacramento-San Joaquin Bay-Delta estuary, proposes to add over 70,000acres of habitat in the Delta to improve conditions for threatened and endangered aquatic and terrestrial species. This habitat could also be a suitable mosquito breeding habitat, which will be located in close proximity to urban and suburban communities. Wetland management practices and continued pesticide applications in the Delta could mitigate the effects of a new mosquito breeding habitat. Recent legal developments, however, require districts to obtain and comply with Clean Water Act permits, which restrict the application of pesticides in or near waters of the United States. Moreover, the U.S. Environmental Protection Agency has taken the first step in a rulemaking process that could further limit or prohibit the use of certain vector control pesticides in the Delta. In the near term and until less harmful methods for mosquito control are available, local vector control districts’ application of mosquito control pesticides should be exempt from Clean Water Act permit requirements.

Karyotype and Genome Size Estimation ofHaliotis midae: Estimators to Assist Future Studies on the Evolutionary History of Haliotidae

The genome size of the abalone Haliotis midae was determined using flow cytometry and calculated relative to the known genome size of the rainbow trout (Oncorhynchus mykiss). The C value for H. midae was estimated to be 1.43 pg, which is smaller in comparison with other abalone species with the same number of chromosomes (2n = 36), namely H. corrugata, 2.14 pg; H. rufescens, 1.82 pg; and H. fulgens, 1.71 pg. In these Californian abalone species, a positive correlation between C value and the number of metacentric/submetacentric chromosomes with a subsequent loss of submetacentric/subtelocentric chromosomes was observed. Karyotypic analysis in H. midae indicates 6M 10SM 2 ST (metacentric submetacentric subtelocentric) chromosome pairs, the lowest number of metacentric and the highest number of subtelocentric chromosomes when compared with the Californian species. This pattern, in the light of recent phylogenetic and cytogenetic evidence, leads us to hypothesize that during the evolution of the genus, there were some preferential karyotypic rearrangements. Research on the genome size of other abalone species in general and specifically South African species, combined with chromosome banding techniques, could provide more insight into the evolution of this genus.

First Alaocybites weevil (Insecta: Coleoptera: Curculionoidea) from the Eastern Palaearctic: a new microphthalmic species and generic relationships

The genus Alaocybites (Coleoptera: Curculionoidea), previously consisting of two eyeless Californian species, is for the fi rst time reported from the East Palaearctic Region. A new microphthalmic species, A. egorovi sp.n., is described from Primor-sky Kray, the Far East of Russia. An early Late Pliocene Alaskan weevil fossil previously attributed to the molytine genus Otibazo is assigned to Alaocybites and found almost undistinguishable from A. egorovi sp.n. Results of preliminary phylo-genetic analyses aimed to clarify phylogenetic affinities of Alaocybites are found controversial and inconclusive. The uncer-tainties of the contemporary classifi cation of orthocerous weevils are briefl y discussed. Alaocybites is provisionally retained in Raymondionymidae, with the absence of tarsomere IV on each leg being the family's most plausible apomorphy. Mono-phyly, geographical distribution and internal relationships of Raymondionymidae are briefl y discussed and compared with other predominantly Mediterranean groups of eyeless beetles. External and genital morphological characters of edaphic weevils with reduced eyes habitually resembling, or thought to be related to, Alaocybites are extensively illustrated.

Riparian Seedling Mortality from Simulated Water Table Recession, and the Design of Sustainable Flow Regimes on Regulated Rivers

Seasonal water limitation exerts a strong ecological filter on stream communities in semiarid regions. For first‐year riparian willow and poplar tree seedlings, desiccation from rapidly declining river flows can limit reproduction, especially on rivers in which flow regulation and land conversion have limited the amount of area available for recruitment. We investigated survivorship of first‐year riparian seedlings to simulated river stage declines, focusing on the three dominant species in California's heavily regulated San Joaquin Basin: Fremont cottonwood, Goodding's black willow, and sandbar willow. Seedlings grown in mesocosms were subjected to water table decline rates typical in spring on unregulated and regulated rivers. We compared species' differences in survival time and fit the empirical data to accelerated failure time models that predicted time until death as a function of drawdown rate, initial seedling size, and maternal line. We used Akaike information criteria to select the best model for each species. Water table decline rates ≥ 6 cm/day were lethal to all species. At an intermediate rate (3 cm/day) survival varied most among species (12–38%) and was highest for Goodding's black willow. Failure time models indicated no maternal effects on survival but that initial seedling size was important for cottonwood. Using these models, we simulated survivable flow scenarios on the Tuolumne River (CA) and assessed the survivability of actual flow releases in two representative years. This modeling approach shows promise for optimizing flow releases to restore pioneer riparian habitat on regulated rivers in some of the world's most water‐limited regions.

Potential risks of systemic imidacloprid to parasitoid natural enemies of a cerambycid attacking Eucalyptus

A community of insect herbivores has established on eucalyptus species in California following their introduction from Australia. A number of the species are under complete or partial biological control. A response to introduction of additional pest species into the complex has been the application of systemic insecticides to infested trees. Natural enemies that have been introduced to control the various pest species feed on the nectar of treated trees, and thus may be affected by these pesticides. In this study, Eucalyptus rudis trees were treated at label rates with the neonicotinoid systemic insecticide imidacloprid and nectar sampled at 5 months post-treatment during the spring bloom. The concentration of imidacloprid and its toxic metabolites in nectar was measured by ELISA at 660 ppb. Adults of the encyrtid egg parasitoid Avetianella longoi that were fed floral nectar collected from treated trees had significantly lower survival and reproductive fitness than adults fed nectar from untreated trees. In feeding bioassays, in which the adults were fed a range of concentrations of imidacloprid in sugar water, the LC 50 for A. longoi was 212 ppb imidacloprid. Bioassays were also conducted with the braconid larval parasitoid, Syngaster lepidus. The LC 50 for S. lepidus was 288 ppb imidacloprid. The insecticide appears to be concentrating in the nectar at higher levels than reported from other plant species and at concentrations exceeding the LC 50 for two important parasitoids. If tree treatments become widespread as a result of continual introductions of new eucalypt herbivores, established biological control programs could be at significant risk.

The proteomic response of the mussel congenersMytilus galloprovincialisandM. trossulusto acute heat stress: implications for thermal tolerance limits and metabolic costs of thermal stress

The Mediterranean blue mussel, Mytilus galloprovincialis, an invasive species in California, has displaced the more heat-sensitive native congener, Mytilus trossulus, from its former southern range, possibly due to climate change. By comparing the response of their proteomes to acute heat stress we sought to identify responses common to both species as well as differences that account for greater heat tolerance in the invasive. Mussels were acclimated to 13°C for four weeks and exposed to acute heat stress (24°C, 28°C and 32°C) for 1 h and returned to 13°C to recover for 24 h. Using two-dimensional gel electrophoresis and tandem mass spectrometry we identified 47 and 61 distinct proteins that changed abundance in M. galloprovincialis and M. trossulus, respectively. The onset temperatures of greater abundance of some members of the heat shock protein (Hsp) 70 and small Hsp families were lower in M. trossulus. The abundance of proteasome subunits was lower in M. galloprovincialis but greater in M. trossulus in response to heat. Levels of several NADH-metabolizing proteins, possibly linked to the generation of reactive oxygen species (ROS), were lower at 32°C in the cold-adapted M. trossulus whereas proteins generating NADPH, important in ROS defense, were higher in both species. The abundance of oxidative stress proteins was lower at 32°C in M. trossulus only, indicating that its ability to combat heat-induced oxidative stress is limited to lower temperatures. Levels of NAD-dependent deacetylase (sirtuin 5), which are correlated with lifespan, were lower in M. trossulus in response to heat stress. In summary, the expression patterns of proteins involved in molecular chaperoning, proteolysis, energy metabolism, oxidative damage, cytoskeleton and deacetylation revealed a common loci of heat stress in both mussels but also showed a lower sensitivity to high-temperature damage in the warm-adapted M. galloprovincialis, which is consistent with its expanding range in warmer waters.

Does UV-B Radiation Affect Embryos of Three High Elevation Amphibian Species in California?

Abstract Declines and extinctions of amphibians in well-protected habitats suggest that global atmospheric factors may be responsible. We tested effects of field exposures of ultraviolet radiation (UV-B) on embryo hatching success and time to hatching in three anurans that inhabit high elevation areas of the Sierra Nevada in California, USA. While few obvious environmental impacts have occurred in the high elevation area of the Sierra Nevada, two of the three most common anurans, the Yosemite Toad (Bufo canorus) and the Southern Mountain Yellow-legged Frog (Rana muscosa), have suffered severe population declines while the sympatric Pacific Treefrog (Pseudacris regilla) has remained relatively abundant. Previous studies have shown that hatching of P. regilla embryos at lower elevations are not affected negatively by UV-B radiation. We hypothesized that differences in UV sensitivity may help explain why P. regilla remain abundant while B. canorus and R. muscosa have declined sharply. We conducted field expe...

Home range, habitat use, and site fidelity of barred sand bass within a southern California marine protected area

Barred sand bass ( Paralabrax nebulifer) is an important recreational species in southern California, which may benefit from marine protected areas. Understanding species movement patterns is a key component to identifying if a species will benefit from marine protected areas. Acoustic telemetry methods coupled with a GIS were used to quantify the home range, site fidelity, and habitat use of barred sand bass at the Catalina Marine Science Center Marine Life Refuge located at Santa Catalina Island, California. Barred sand bass utilized soft-sediment habitats within close proximity to rocky reefs and had home ranges that averaged 10,003 m 2 ± 4773 m 2 (±SD). During the day, individuals generally used multiple areas on or near reefs, and at night repeatedly used one area over soft-sediment habitat. Fifty percent of the acoustically tagged individuals exhibited year round fidelity to the study site indicating that even small marine protected areas may be an effective management strategy.

Cumulative effects of land use, altered fire regime and climate change on persistence ofCeanothus verrucosus, a rare, fire‐dependent plant species

AbstractMediterranean ecosystems are among the highest in species richness and endemism globally and are also among the most sensitive to climate and land‐use change. Fire is an important driver of ecosystem processes in these systems; however, fire regimes have been substantially changed by human activities. Climate change is predicted to further alter fire regimes and species distributions, leading to habitat loss and threatening biodiversity. It is currently unknown what the population‐level effects of these landscape‐level changes will be. We linked a spatially explicit stochastic population model to dynamic bioclimate envelopes to investigate the effects of climate change, habitat loss and fragm entation and altered fire regime on population abundances of a long‐lived obligate seeding shrub,Ceanothus verrucosus, a rare endemic species of southern California. We tested a range of fire return intervals under the present and two future climate scenarios. We also assessed the impact of potential anthropogenic land‐use change by excluding land identified as developable by local governments. We found that the 35–50 year fire return interval resulted in the highest population abundances. Expected minimum population abundance (EMA) declined gradually as fire return interval increased, but declined dramatically for shorter fire intervals. Simulated future development resulted in a 33% decline in EMA, but relatively stable population trajectories over the time frame modeled. Relative changes in EMA for alternative fire intervals were similar for all climate and habitat loss scenarios, except under the more severe climate scenario which resulted in a change in the relative ranking of the fire scenarios. Our results show climate change to be the most serious threat facing obligate seeding shrubs embedded in urban landscapes, resulting in population decline and increased local extirpation, and that likely interactions with other threats increase risks to these species. Taking account of parameter uncertainty did not alter our conclusions.

Direct seeding is more cost effective than container stock across ten woody species in California

Abstract The planting of native woody plants is a cornerstone of many habitat restoration projects. Current techniques for revegetating disturbed or reclaimed plant communities often consist primarily of planting trees and shrubs from container stock, which can be costly to buy or produce, time-consuming to plant (an additional cost), and logistically difficult for large-scale restoration projects. We tested whether direct seeding woody species was more cost effective than planting container stock. During fall 2004, we planted 3 sites encompassing the ecotone of foothill riparian and woodland habitats in northern California with 10 native species of woody plants, both as container stock and direct seed. Data on survival were collected over a 2-y period. Across species, the planting success of direct-seeded plants, but not container plants, increased significantly with increasing mean seed size. Although seeds generally had lower individual planting success than did container stock, this was always offset by the higher costs of purchasing and planting container stock. Direct seeding was up to 29 times more cost effective than planting container stock when considering base costs (not including fixed costs of tubes, irrigation, and herbicide). Including these additional costs reduced the cost advantage, but direct seeding remained more cost effective per surviving plant across all species, and especially so for large-seeded species.

Molecular characterization of Sarcocystis neurona strains from opossums ( Didelphis virginiana) and intermediate hosts from Central California

Sarcocystis neurona is a significant cause of neurological disease in horses and other animals, including the threatened Southern sea otter ( Enhydra lutris nereis). Opossums ( Didelphis virginiana), the only known definitive hosts for S. neurona in North America, are an introduced species in California. S. neurona DNA isolated from sporocysts and/or infected tissues of 10 opossums, 6 horses, 1 cat, 23 Southern sea otters, and 1 harbor porpoise ( Phocoena phocoena) with natural infections was analyzed based on 15 genetic markers, including the first internal transcribed spacer (ITS-1) region; the 25/396 marker; S. neurona surface antigen genes (snSAGs) 2, 3, and 4; and 10 different microsatellites. Based on phylogenetic analysis, most of the S. neurona strains segregated into three genetically distinct groups. Additionally, fifteen S. neurona samples from opossums and several intermediate hosts, including sea otters and horses, were found to be genetically identical across all 15 genetic markers, indicating that fatal encephalitis in Southern sea otters and equine protozoal myeloencephalitis (EPM) in horses is strongly linked to S. neurona sporocysts shed by opossums.