Populations often vary in their evolutionary responses to a shared environmental perturbation. A key hurdle in building more predictive models of rapid evolution is understanding this variation-why do some populations and traits evolve while others do not? We combined long-term demographic and environmental data, estimates of quantitative genetic variance components, a resurrection experiment and individual-based evolutionary simulations to gain mechanistic insights into contrasting evolutionary responses to a severe multi-year drought. We examined five traits in two populations of a native California plant, Clarkia xantiana, at three time points over 7 years. Earlier flowering phenology evolved in only one of the two populations, though both populations experienced similar drought severity and demographic declines and were estimated to have considerable additive genetic variance for flowering phenology. Pairing demographic and experimental data with evolutionary simulations suggested that while seed banks in both populations probably constrained evolutionary responses, a stronger seed bank in the non-evolving population resulted in evolutionary stasis. Gene flow through time via germ banks may be an important, underappreciated control on rapid evolution in response to extreme environmental perturbations.

This paper examines the shifting fortunes of the Diablo Canyon Nuclear Power Plant in California to better understand how asset owners are dealing with an increasingly-significant problem in changing energy landscapes: the devaluation of large fixed capital assets. In 2016, Pacific Gas and Electric Company announced a Joint Proposal to retire the Diablo Canyon plant by 2025, the result of a negotiated compromise with labor unions, environmental and community groups. Heralded by many commentators as a model for “just transitions” in the energy sector, this agreement has lately been called into question as new subsidies and political coalitions have emerged to support for the plant's continued operation. This paper investigates the political and economic conditions for the Joint Proposal as an example of “negotiated devaluation,” aiming to understand why and how this strategy took shape, and what lessons it offers for other transition processes. Linking literatures on just transitions and devaluation in the energy sector, we show how negotiated devaluation may offer an emerging strategy for owners of energy assets to manage decline in a changing energy landscape. The case also demonstrates the political contingency of these coalitions and the transitions they subtend, and the limited dimensions of justice that might be affirmed in them.

Abstract Day‐to‐day synchrony between flower opening and pollinator activity is important for maximizing plant fitness. A succulent, Bulbine frutescens (L.) Willd., is an ideal model for studying synchrony in response to daily weather as it flowers year‐round. Additionally, it has self‐incompatible flowers that open for just one day, making it essential that flower opening matches pollinator activity. Observations were made on urban plants in California, USA, with validation measurements in the native range in South Africa. Independent observations indicated that flowers open primarily after favourable conditions the previous day, specifically air temperatures above 15°C. Solar radiation was experimentally shown to have limited, but significant effects. Pollinators, mostly bee species, had similar temperature thresholds to flowers. Developmental constraints on flowers were hypothesized to delay opening by a day. Flower bud growth was closely related to temperature, with warm days resulting in sufficient growth for buds to become competent to open the following day. Laboratory experiments demonstrated that competent flowers were suppressed from opening until at least 16 h was accumulated in which temperatures were above 12°C; thus, on many cool days, sufficient development to cause flower opening would only occur a day after favourable weather. Based upon regression models of pollinator and flower response to weather, fitness was estimated as a function of synchrony, over 20 years of weather from California and across the natural range in South Africa. Flowers responding to either the previous day's or current day's weather resulted in similar predicted fitness, with flower response to the current day's weather leading to a slightly higher cost, that is, flowers opened when pollinators would be absent. Multiple temperature responsive constraints on bud growth and development result in delays in flower opening, such that flower opening occurs the day after favourable weather. Given the high correlation between daily temperatures in USA and South African winter‐rainfall environments, behaviour predicting the following day's weather results in high fitness. Many pollinators share similar temperature thresholds for activity, thus diverse plants may have evolved predictive behaviour maximizing daily synchrony between pollinators and flower opening. Read the free Plain Language Summary for this article on the Journal blog.

Estimates of biomass reductions of ozone sensitive herbaceous plants in California

Falling costs of lithium-ion (Li-ion) batteries havemade themattractive for grid-scale energy storage applications. Energy storagewill become increasingly important as intermittent renewable generationand more frequent extreme weather events put stress on the electricitygrid. Environmental groups across the United States are advocatingfor the replacement of the highest-emitting power plants, which runonly at times of peak demand, with Li-ion battery systems. We analyzethe life-cycle cost, climate, and human health impacts of replacingthe 19 highest-emitting peaker plants in California with Li-ion batteryenergy storage systems (BESS). Our results show that designing Li-ionBESS to replace peaker plants puts them at an economic disadvantage,even if facilities are only sized to meet 95% of the original plants’load events and are free to engage in arbitrage. However, five of19 potential replacements do achieve a positive net present valueafter including monetized climate and human health impacts. TheseBESS cycle far less than typical front-of-the-meter batteries andrely on the frequency regulation market for most of their revenue.All projects offer net air pollution benefits but increase net greenhousegas emissions due to electricity demand during charging and upstreamemissions from battery manufacturing.

A Sequential Real Options Analysis for Renewable Power-to-Hydrogen Plants in Germany and California

California contains a diverse flora, and knowledge of the pathogens that threaten those plants is essential to managing their long-term health. To better understand threats to California plant health, a meta-analysis of Phytophthora detections within the state was conducted using publicly available sequences as a primary source of data rather than published records. Accessions of internal transcribed spacer (ITS) ribosomal DNA were cataloged from 800 Californian Phytophthora isolates, analyzed, and determined to correspond to 80 taxa, including several phylogenetically distinct provisional species. A number of Phytophthora taxa not previously reported from California were identified, including 20 described species. Pathways of introduction and spread were analyzed by categorizing isolates' origins, grouped by land-use: (i) agriculture, (ii) forests and other natural ecosystems, (iii) horticulture and nurseries, or (iv) restoration outplantings. The pooled Phytophthora metacommunities of the restoration outplantings and horticulture land-use categories were the most similar, whereas the communities pooled from forests and agriculture were least similar. Phytophthora cactorum, P. pini, P. pseudocryptogea, and P. syringae were identified in all four land-use categories, while 13 species were found in three. P. gonapodyides was the most common species by number of ITS accessions and exhibited the greatest diversity of ITS haplotypes. P. cactorum, P. ramorum, and P. nicotianae were associated with the greatest number of host genera. In this analysis, the Phytophthora spp. most prevalent in California differ from those compiled from the scientific literature.

Interest in industrial hemp (Cannabis sativa) as a potential crop led to the establishment of commercial fields in a number of counties in California in 2019 and 2020. Plants in these fields developed different types of virus-like symptoms. The most prevalent type was stunted and bushy plants with distorted, upcurled, and yellowed leaves, which were similar to those associated with curly top disease (CTD) caused by the beet curly top virus (BCTV). This beet leafhopper-vectored virus is endemic in California and can cause economic losses to processing tomato production. Using a multiplex PCR test, BCTV infection was detected in 89% of hemp samples with CTD-like symptoms from Fresno, San Bernardino, and Ventura counties. Other symptom types had low incidence of BCTV infection and were associated with other factors. Hemp plants in California were infected only with the mild-type strains, BCTV-CO and BCTV-Wor, and often in mixed infection (43% of samples). Finally, using an infectious clone of a BCTV-CO isolate from hemp, we demonstrated that agroinoculated hemp plants developed these CTD-like symptoms, thereby fulfilling Koch's postulates for the disease.

This paper presents and defines a method for standardizing ecosystem services in the context of hydropower projects and demonstrates its applicability through the Folsom hydropower plant in California. In particular, this paper uses the Final Ecosystem Goods and Services Classification System (FEGS-CS) to provide a structured framework for identifying ecosystems, the potential services they provide, and their beneficiaries. In this paper, the benefit transfer technique is used for estimating non-market values for new policy contexts. The total value of this case study is about USD 169 million per year for the Folsom hydropower plant in California. The advantage of the proposed framework lies in its ability to be imported and applied to any other hydropower facility, and it can be extensively used both for new and existing power plants.

Background Aroeira or Brazilian peppertree, Schinus terebinthifolia Raddi (Anacardiaceae: Rhoeae), is one of the worst invasive plants in California, Florida, and Hawaii, USA because of its wide distribution, adaptation to various habitats, toxicity, and demonstrated negative impacts on biodiversity. Chemical and mechanical methods provide only temporary control, are expensive, may damage native plants, and often create disturbance conducive to reinvasion by Brazilian peppertree and other invasive weeds. The leaflet galling psyllid Calophya terebinthifolii Burckhardt & Basset (Calophyidae: Calophyinae) is [...]

The Department of Fish and Wildlife manages California's diverse fish, wildlife, and plant resources, and the habitats upon which they depend, for their ecological values and for their use and enjoyment by the public.

The Department of Fish and Wildlife manages California's diverse fish, wildlife, and plant resources, and the habitats upon which they depend, for their ecological values and for their use and enjoyment by the public.

Pistachio bushy top syndrome (PBTS) is a serious problem for pistachio growers in the western United States, but the cause of this disorder remains controversial. Recently, it was proposed that the Rhodococcus species R. fascians and R. corynebacterioides caused PBTS outbreaks in 2011 and 2015. To investigate the association of Rhodococcus spp. with PBTS in California's pistachio-growing region, Rhodococcus-like isolates were collected from diverse hosts and environments, including pistachio nurseries and orchards. Whole genome sequence analysis of 231 isolates revealed their evolutionary relationships and identified six Rhodococcus species. Combined with data on geography and host of origin, the data reveal that Rhodococcus generally, and R. fascians specifically, is ubiquitous in nature, frequently occurring in both symptomatic and asymptomatic pistachio trees and on other woody and native species. Core gene and single nucleotide polymorphism-based phylogenies and pangenome analyses differentiate R. fascians into distinct genotypes. Although we found examples of common genotypes shared between nurseries and orchards, the observed patterns are most consistent with an environmental source of strains and do not support a scenario in which individual nurseries are point sources of Rhodococcus. Moreover, none of the collected strains harbored known virulence genes, calling into question the role of these common environmental bacteria in causing PBTS. [Formula: see text] Copyright © 2022 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

Three species of Phasmarhabditis were recovered from 75 nurseries and garden centers in 28 counties in California during fall and winter 2012–2021. A total of 18 mollusk species were recovered, most of them invasive. Nematodes were identified by sequencing the D2-D3 expansion segments of the large subunit (LSU or 28S) rRNA. Based on these surveys, P. californica was the most widespread species (37 isolates, 53.6% recovery); followed by P. hermaphrodita (26 isolates; 37.7% recovery); P. papillosa and a closely related P. papillosa isolate (6 isolates; 8.7% recovery). Nematode isolates were mainly collected from four invasive slugs (Deroceras reticulatum, D. laeve, Arion hortensis agg, Ambigolimax valentianus) and snails (Oxychilus spp. and Discus spp.). Results suggest that P. californica and P. hermaphrodita share an ecological niche in Northern, Central, Coastal, and Southern California, north of Los Angeles County.

Severeacute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNAconcentrations in wastewater settled solids correlate well with coronavirusdisease 2019 (COVID-19) incidence rates (IRs). Here, we develop distributedlag models to estimate IRs using concentrations of SARS-CoV-2 RNAfrom wastewater solids and investigate the impact of sampling frequencyon model performance. SARS-CoV-2 N gene and pepper mild mottle virus(PMMoV) RNA concentrations were measured daily at four wastewatertreatment plants in California. Artificially reduced data sets wereproduced for each plant with sampling frequencies of once every 2,3, 4, and 7 days. Sewershed-specific models that related daily N/PMMoVto IR were fit for each sampling frequency with data from mid-November2020 through mid-July 2021, which included the period of time duringwhich Delta emerged. Models were used to predict IRs during a subsequentout-of-sample time period. When sampling occurred at least once every4 days, the in- and out-of-sample root-mean-square error changed by<7 cases/100 000 compared to daily sampling across sewersheds.This work illustrates that real-time, daily predictions of IR arepossible with small errors, despite changes in circulating variants,when sampling frequency is once every 4 days or more. However, reducedsampling frequency may not serve other important wastewater surveillanceuse cases.

Drought and competition affect how morphological and physiological traits are expressed in plants. California plants were previously found to respond less negatively to resource limitation compared to invasive counterparts. In a glasshouse in Santa Cruz, CA, USA, we exposed five native California C3 grassland species to episodic drought and competition (via five locally invasive species). We hypothesized that leaf morphology would be more affected by competition, and leaf photosynthetic gas exchange more so by drought, consistent with optimal partitioning and environmental filter theories. We expected that traits would exhibit trade‐offs along a spectrum for resource conservatism versus acquisition. Bromus carinatus had greater photosynthetic recovery, while Diplacus aurantiacus had lower percent loss of net assimilation (PLA) and intrinsic water‐use efficiency (iWUE) during drought and competition simultaneously compared to just drought. Stipa pulchra and Sidalcea malviflora gas exchange was unaffected by drought, and leaf morphology exhibited drought‐related adjustments. Lupinus nanus exhibited trait adjustments for competition but not drought. Functional traits sorted onto two principal components related to trade‐offs for resource conservatism versus acquisition, and for above‐ versus belowground allocation. In summary, morphological traits were affected by competition and drought, whereas physiological traits, like leaf gas exchange, were primarily affected by drought. The grassland plants we studied showed diverse responses to drought and competition with trait trade‐offs related to resource conservatism versus acquisition, and for above‐ versus belowground allocation consistent with optimal partitioning and environmental filter theories. Diplacus aurantiacus experienced competitive release based on greater iWUE and lower PLA when facing drought and competition.

Estuaries are special places that form where freshwater from the land mixes with saltwater from the ocean, which is pushed inland by the tides. This mixing creates diverse habitats that support a variety of specially adapted species. In estuaries with Mediterranean climates (similar to that of the Mediterranean region in Europe), winters are wet and summers are dry. Some winters have lots of rain, others have almost none. The animals and plants of California’s San Francisco Estuary have adapted to these variable conditions. But humans have changed how and when the water flows through the Estuary, making it tough for some species to survive. Climate change is likely to bring hotter air and water temperatures, more extreme floods and droughts, and rising sea levels, further complicating species survival. In this article, we discuss how ecosystem restoration and water management can help species survive in a changing climate.

For each geographical region, one of the biggest challenges in reaching a zero-carbon grid is identifying sources of electricity that match the seasonal profile of the load. Summer-dominant solar electricity generation can often be balanced by winter-dominant wind electricity generation. Together with long-duration storage, balanced solar and wind generation are well positioned to provide reliable renewable electricity. However, in some locations the wind may not complement solar energy so well. For example, currently California's wind turbines produce more electricity during summer than winter, raising the question of whether all future wind plants in California will exhibit the same seasonality. As a response to this question, in this paper, we analyzed the generation from existing California wind plants and simulated potential onshore wind resource for the whole state using a metric that reflects the relative wind resource in winter. Our results indicate that the seasonality of the wind can vary for very small spatial difference with more than half of California showing stronger wind resource in the winter compared with the summer despite the current observation of the opposite trend. This study differentiates the seasonality of potential wind resources to inform the creation of a reliable, 100%-renewable-driven grid.

Application of spectral beam splitting using Wavelength-Selective filters for Photovoltaic/Concentrated solar power hybrid plants

Planning the restoration of membranes in RO desalination using a digital twin