Juniperus of Canada and the United States: Taxonomy, Key and Distribution.

The taxonomy of Juniperus of Canada and the United States is reviewed and keys to the 18 species, 5 varieties and 3 formas are presented as well as distribution maps.Integrative Biolog

Notes on Iowa Grasses

In presenting this list of Iowa Grasses, no claim is made of reporting any species new to the state. The list does include, however, a number of rarer forms, species that are very local in habitat or in distribution and several strays and introductions that are perhaps worthy of mention. There have been a number of systematic lists of Iowa grasses published heretofore. None of them have emphasized to any great extent the habitat, the ecological side of their distribution. It is to stress this phase of grass study, that the present paper is written. Grasses furnish valuable criteria of the ecological conditions of the area in which they grow. The paper is based on extensive field observations and studies, ranging over several years and including many parts of the state. Specimens listed are preserved at the herbarium at Iowa City. They were selected from a collected list of some 100 species. In this field work, which I consider one of the most important phases of botanical study, no efforts were spared to gain a proper appreciation of habitat and relationship with other plants. Dates were preserved, that flowering and fruiting seasons might be ascertained. The soil composition, moisture supply, exposure and other ecological factors were considered

APPLICATION OF A BIO-ECONOMIC-ENGINEERING MODEL FOR SHRIMP MARICULTURE SYSTEMS

Resource /Energy Economics and Policy,

Phylogenomic evidence for ancient recombination between plastid genomes of the Cupressus-Juniperus-Xanthocyparis complex (Cupressaceae)

Background: Phylogenetic relationships among Eastern Hemisphere cypresses, Western Hemisphere cypresses, junipers, and their closest relatives are controversial, and generic delimitations have been in flux for the past decade. To address relationships and attempt to produce a more robust classification, we sequenced 11 new plastid genomes (plastomes) from the five variously described genera in this complex (Callitropsis, Cupressus, Hesperocyparis, Juniperus, and Xanthocyparis) and compared them with additional plastomes from diverse members of Cupressaceae. Results: Phylogenetic analysis of protein-coding genes recovered a topology in which Juniperus is sister to Cupressus, whereas a tree based on whole plastomes indicated that the Callitropsis-Hesperocyparis-Xanthocyparis (CaHX) clade is sister to Cupressus. A sliding window analysis of site-specific phylogenetic support identified a ~ 15 kb region, spanning the genes ycf1 and ycf2, which harbored an anomalous signal relative to the rest of the genome. After excluding these genes, trees based on the remainder of the genes and genome consistently recovered a topology grouping the CaHX clade and Cupressus with strong bootstrap support. In contrast, trees based on the ycf1 and ycf2 region strongly supported a sister relationship between Cupressus and Juniperus. Conclusions: These results demonstrate that standard phylogenomic analyses can result in strongly supported but conflicting trees. We suggest that the conflicting plastomic signals result from an ancient introgression event involving ycf1 and ycf2 that occurred in an ancestor of this species complex. The introgression event was facilitated by plastomic recombination in an ancestral heteroplasmic individual carrying distinct plastid haplotypes, offering further evidence that recombination occurs between plastomes. Finally, we provide strong support for previous proposals to recognize five genera in this species complex: Callitropsis, Cupressus, Hesperocyparis, Juniperus, and Xanthocyparis

Large-scale structure of brown rat (Rattus norvegicus) populations in England: effects on rodenticide resistance

The brown rat (Rattus norvegicus) is a relatively recent (<300 years) addition to the British fauna, but by association with negative impacts on public health, animal health and agriculture, it is regarded as one of the most important vertebrate pest species. Anticoagulant rodenticides were introduced for brown rat control in the 1950s and are widely used for rat control in the UK, but long-standing resistance has been linked to control failures in some regions. One thus far ignored aspect of resistance biology is the population structure of the brown rat. This paper investigates the role population structure has on the development of anticoagulant resistance. Using mitochondrial and microsatellite DNA, we examined 186 individuals (from 15 counties in England and one location in Wales near the Wales–England border) to investigate the population structure of rural brown rat populations. We also examined individual rats for variations of the VKORC1 gene previously associated with resistance to anticoagulant rodenticides. We show that the populations were structured to some degree, but that this was only apparent in the microsatellite data and not the mtDNA data. We discuss various reasons why this is the case. We show that the population as a whole appears not to be at equilibrium. The relative lack of diversity in the mtDNA sequences examined can be explained by founder effects and a subsequent spatial expansion of a species introduced to the UK relatively recently. We found there was a geographical distribution of resistance mutations, and relatively low rate of gene flow between populations, which has implications for the development and management of anticoagulant resistance

Weed Succession on an Abandoned Roadway

In 1912, Dr. B. Shimek of the State University of Iowa, presented a paper, An Artificial Prairie, before the Botanical Society of America. In this article, he described and explained a strip of man-made prairie bordering the roadway leading north from Homestead to Amana, Iowa. This road was cut in 1856 through the dense upland woods lying between the two villages and bordering the valley of the Iowa River. Its inception and maintenance provided conditions of such a xerophytic character that a typical prairie strip was produced. By means of comparison between a comprehensive list of the xerophytic plants growing on this prairie and a similar list compiled from collections of plants growing in the deep woods habitat just a few feet back of the clearing, he was able to prove the existence of a prairie in the heart of the forest

Long distance gene flow facilitated by bird-dispersed seeds in wind-pollinated species: A story of hybridization and introgression between Juniperus ashei and J. ovata told by nrDNA and cpDNA

nrDNA and cpDNA were sequenced of J. ashei and J. ovata from populations throughout their ranges. No J. ashei populations were found to be pure in their nrDNA for every tree, however all J. ashei trees in every population contained only the pure J. ashei chloroplast type. Populations of J. ovata in trans-Pecos Texas were almost pure in both nrDNA and cp DNA. Several plants in the J. ashei range contained J. ovata-type nrDNA (White Cliffs, AR, 3/10); Ranger, TX (1/5); Waco, TX (1/12). Every J ashei population contained at least 1 plant with hybrid (heterozygous) nrDNA and 3 J. ovata populations contained putative hybrids (by nrDNA), but one population had only pure J. ovata trees. The presence of ovata germplasm within J. ashei populations seems best explained by long distance bird dispersal of J. ovata seeds (thence seedlings and J. ovata trees and hybrids) in the disjunct J. ashei populations. The reason for the absence of ovata paternal cp, which is distributed by pollen in J. ashei populations is not known. Judged by distribution of cp data, there is very little movement of cp genomes. In contrast, nrDNA polymorphisms indicate there is considerable gene flow between J. ashei and J. ovata, but primarily in the direction of J. ovata to J. ashei which may be explained by a combination of bird migration pattern and recurring and preferential F1-hybrid formation

Chloroplast capture by a new variety, Juniperus sabina var. balkanensis R. P. Adams and A. N. Tashev, from the Balkan peninsula: A putative stabilized relictual hybrid between J. sabina and ancestral J. thurifera

An example of chloroplast capture has been found in Juniperus sabina from Bulgaria and Greece in the Balkan peninsula. The cpDNA from these populations is very uniform and is nearly identical to that of J. thurifera (currently growing in France, Spain and Morocco). The new taxon is recognized as Juniperus sabina var. balkanensis R. P. Adams and A. Tashev. At present, the variety, with the thurifera cpDNA, is known only from Bulgaria and Greece