The Effects of Organizational, Community, and State Regulatory Characteristics on Texas Oil and Gas Extraction Facility Venting and Flaring Practices

Why do some companies release more methane than others? Using a mixed methods approach, I explore this question by analyzing variation in Texas oil and gas extraction facility venting and flaring practices. The methane emissions from oil and gas venting and flaring contribute to global climate change, making the practice a growing concern. Using an open systems organizational theory approach, I develop a conceptual model to explain how organizational power relates to methane emissions from venting and flaring by the oil and gas extraction industry. I test the conceptual model with several sources of data and analyses. First, I analyze archival information to show how, due to direct involvement of powerful oil and gas companies, policy changed to increase the legal opportunities for companies to vent or flare gas. Second, drawing upon quantitative environmental justice research methods, I create a geographic information system to examine how community inequality is related to environmental inequality. Third, I analyze a zero-inflated negative binomial regression model that demonstrates that extreme venting and flaring is associated with low poverty, less politically organized, and predominately Hispanic neighborhoods. Finally, I explore the effects of the organizational characteristics of facilities, the companies that directly own them, and the political legal environment in which they are embedded on the environmental efficiency of facility operations through a clustered two-part hurdle regression model. I find subsidiary organizations are more prone to pollution because there is a liability firewall that protects ultimate parent companies from possible social repercussions. Findings suggest political and organizational power are key factors contributing to the environmental decisions of organizations. By enacting new state policy, methane emissions could be reduced

New perspectives on evolutionary relationships within Pinus (Pinaceae) and within subsection Ponderosae (subgenus Pinus)

A fossil-calibrated phylogenetic framework based on exemplars from each of the four taxonomic sections within Pinus was created using multiple nuclear and chloroplast loci. Calibration at the well-defined subgeneric split within Pinus with either fossil leaves and cones (ca. 45 million years ago) or fossil wood (ca. 85 million years ago) provides a reasonable starting point. Despite a wide difference in rates between loci, this work infers a moderate tempo of mutation rate in Pinus, and concludes that the within-locus rate variation and the leaves vs. wood question are both minor factors in comparison to the enormous effects of incorrect fossil/node association. Next, I used full taxonomic sampling with multiple individuals per species and two nuclear loci to create independent phylogenies for 18 species in subsection Ponderosae (Section Trifoliae, subgenus Pinus). I estimate that some species have enormous effective population sizes (> 105 individuals). This factor and an inferred origin 15 million years ago contribute to the lack of species-level coalescence and the incongruence between Ponderosae gene trees. Pinus jeffreyi is allied with Sabinianae, as proposed from terpene biochemistry. I observed one instance where reticulate evolution is likely. Pinus coulteri accessions resolve with Sabinianae at one locus, but in a monophyletic clade sister to other Ponderosae at the other locus, suggesting that this species originated as a diploid hybrid. Similar incongruence between loci for accessions of the P. ponderosa/P. washoensis complex could also be the result of introgression. Using this phylogenetic framework, I focused on three sympatric Ponderosae (P. washoensis, P. ponderosa, and P. jeffreyi) to evaluate the genetic distinctiveness and specific status of P. washoensis. Population-level sampling with faster-evolving nuclear microsatellite loci reveals a clear divergence between P. jeffreyi and the P. ponderosa/P. washoensis complex. Using allele frequencies, I observed a weak cluster of traditional P. washoensis with high-elevation putative P. washoensis populations from Oregon, but other methods show no differentiation between P. ponderosa and P. washoensis. Nuclear admixture and chloroplast haplotype analysis suggest a low level of introgression between P. jeffreyi and P. ponderosa/P. washoensis, providing an important source of migrants into the genetic milieu of these species

Evolutionary relationships among Pinus (Pinaceae) subsections inferred from multiple low-copy nuclear loci

Sequence data from nrITS and cpDNA have failed to fully resolve phylogenetic relationships among Pinus species. Four low‐copy nuclear genes, developed from the screening of 73 mapped conifer anchor loci, were sequenced from 12 species representing all subsections. Individual loci do not uniformly support either the nrITS or cpDNA hypotheses and in some cases produce unique topologies. Combined analysis of low‐copy nuclear loci produces a well‐supported subsectional topology of two subgenera, each divided into two sections, congruent with prior hypotheses of deep divergence in Pinus. The placements of P. nelsonii, P. krempfii, and P. contorta have been of continued systematic interest. Results strongly support the placement of P. nelsonii as sister to the remaining members of sect. Parrya, suggest a moderately well‐supported and consistent position of P. krempfii as sister to the remaining members of sect. Quinquefoliae, and are ambiguous about the placement of P. contorta. A successful phylogenetic strategy in Pinus will require many low‐copy nuclear loci that include a high proportion of silent sites and derive from independent linkage groups. The locus screening and evaluation strategy presented here can be broadly applied to facilitate the development of phylogenetic markers from the increasing number of available genomic resources

Asymmetrical Gene Flow in a Hybrid Zone of Hawaiian Schiedea (Caryophyllaceae) Species with Contrasting Mating Systems

Asymmetrical gene flow, which has frequently been documented in naturally occurring hybrid zones, can result from various genetic and demographic factors. Understanding these factors is important for determining the ecological conditions that permitted hybridization and the evolutionary potential inherent in hybrids. Here, we characterized morphological, nuclear, and chloroplast variation in a putative hybrid zone between Schiedea menziesii and S. salicaria, endemic Hawaiian species with contrasting breeding systems. Schiedea menziesii is hermaphroditic with moderate selfing; S. salicaria is gynodioecious and wind-pollinated, with partially selfing hermaphrodites and largely outcrossed females. We tested three hypotheses: 1) putative hybrids were derived from natural crosses between S. menziesii and S. salicaria, 2) gene flow via pollen is unidirectional from S. salicaria to S. menziesii and 3) in the hybrid zone, traits associated with wind pollination would be favored as a result of pollen-swamping by S. salicaria. Schiedea menziesii and S. salicaria have distinct morphologies and chloroplast genomes but are less differentiated at the nuclear loci. Hybrids are most similar to S. menziesii at chloroplast loci, exhibit nuclear allele frequencies in common with both parental species, and resemble S. salicaria in pollen production and pollen size, traits important to wind pollination. Additionally, unlike S. menziesii, the hybrid zone contains many females, suggesting that the nuclear gene responsible for male sterility in S. salicaria has been transferred to hybrid plants. Continued selection of nuclear genes in the hybrid zone may result in a population that resembles S. salicaria, but retains chloroplast lineage(s) of S. menziesii

A Set of Plastid Loci for Use in Multiplex Fragment Length Genotyping for Intraspecific Variation in <i>Pinus</i> (Pinaceae)

Premise of the study: Recently released Pinus plastome sequences support characterization of 15 plastid simple sequence repeat (cpSSR) loci originally published for P. contorta and P. thunbergii. This allows selection of loci for single-tube PCR multiplexed genotyping in any subsection of the genus. Methods: Unique placement of primers and primer conservation across the genus were investigated, and a set of six loci were selected for single-tube multiplexing. We compared interspecific variation between cpSSRs and nucleotide sequences ofycf1 and tested intraspecific variation for cpSSRs using 911 samples in the P. ponderosa species complex. Results: The cpSSR loci contain mononucleotide and complex repeats with additional length variation in flanking regions. They are not located in hypervariable regions, and most primers are conserved across the genus. A single PCR per sample multiplexed for six loci yielded 45 alleles in 911 samples. Discussion: The protocol allows efficient genotyping of many samples. The cpSSR loci are too variable for Pinus phylogenies but are useful for the study of genetic structure within and among populations. The multiplex method could easily be extended to other plant groups by choosing primers for cpSSR loci in a plastome alignment for the target group

Data from: A set of plastid loci for use in multiplex fragment length genotyping for intraspecific variation in Pinus (Pinaceae)

Premise of the study: Recently released Pinus plastome sequences support characterization of 15 plastid Simple Sequence Repeat (ptSSR) loci originally published for P. contorta and P. thunbergii. This allows selection of loci for single-tube PCR multiplexed genotyping in any subsection of the genus. Methods: Unique placement of primers and primer conservation across the genus were investigated, and a set of six loci were selected for single-tube multiplexing. We compare interspecific variation between ptSSRs and nucleotide sequences of ycf1 then test intraspecific variation for ptSSRs using 911 samples in the P. ponderosa species complex. Results: The ptSSR loci contain mononucleotide and complex repeats with additional length variation in flanking regions. They are not located in hypervariable regions and most primers are conserved across the genus. A single PCR per sample multiplexed for six loci yielded 45 alleles in 911 samples. Discussion: The protocol allows efficient genotyping of many samples. The ptSSR loci are too variable for Pinus phylogenies but are useful for the study of genetic structure within and among populations. The multiplex method could easily be extended to other plant groups by choosing primers for ptSSR loci in a plastome alignment for the target group

Genetic diversity and population structure in Chrysolepis chrysophylla (golden chinquapin; Fagaceae): SSRs vs SNPs

Simple sequence repeat (SSR) and single nucleotide polymorphism (SNP) genotypes on the same plant samples of Chrysolepis chrysophylla (Douglas ex Hook.) Hjelmq. (Fagaceae; golden chinquapin) from 22 sites were used to determine genetic diversity and population structure. One site of C. sempervirens (Kellogg) Hjelmq. allowed interspecific vs. intraspecific comparisons. SSRs and SNPs yielded many similar results. Among-site variation contributed 13% to 17% of the genetic variation and Fst estimates of 0.14 to 0.17 were in the range expected among Fagaceae species rather than among populations within a species. The northern sites tended to group separately on the first two axes of multivariate scatterplots from southern sites. Sites in two geographically isolated areas were divergent: (i) the Hood Canal, Washington population was relatively more genetically distant from other golden chinquapin sites than was our C. sempervirens site; (ii) three coastal southern California sites were moderately diverged. The Hood Canal site had a negative inbreeding coefficient, fewer alleles, lower heterozygosity, and differed from the Skamania County, Washington site as well as all other sites. Hood Canal trees are distinguished by disjunct geography and by these molecular results. This suggests that the golden chinquapin near Hood Canal be treated as a management unit, and potential conservation actions are discussed.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Alignment of 15 cpSSR primer pairs with Pinus plastomes

The published nucleotide sequences for 15 cpSSR primer pairs located within the aligned plastomes of 107 species of Pinus and six Pinaceae outgroups (TreeBase S12640)