GIS Ordination Approach to Model Distribution of Shrub Species in Northern Utah

Anthropogenic and natural disturbances represent a serious threat to natural ecosystems dominated by big sagebrush (Artemisia tridentata). Conservation efforts aim to restore original species composition and prevent the invasion of undesirable species. In order to restore the historic plant communities, we need a clear understanding of how species compositions are distributed along environmental gradients. Species ordination is a process of placing plant species along environmental gradients. This study was conducted in Rich County, Utah, where substantial changes in species composition have been documented in recent years. Field data, literature review, multivariate analyzes, GIS and remote sensing techniques, and expert knowledge were used to define environmental variables and their respective suitability ranges of where shrub species may occur along this area. Ordination and CART- statistical analyzes were used to estimate and predict suitability of shrub species along environmental gradients. GIS procedures were used to spatially predict species distribution. Field data and the Southwest Regional Gap Analysis Project data provided useful information to build the model and 20 percent of field data was withheld to cross-validate the findings. Final results showed that the shrub species distribution in the rangelands of Northern Utah, specifically Rich County, might be driven by precipitation and temperature gradients -influenced greatly by elevation. Slope contributing area, NDVI, and solar radiation were statistically significant factors explaining shrub distribution. To our perception, soil moisture availability might be the most explanatory variable behind these findings. In the model validation, the Kappa coefficient was K = 61.3 percent and the overall model accuracy was 74 percent. The location of species distribution areas, in the final map, can be useful to managers in order to define where resources might be allocated to preserve and restore these native rangeland ecosystems

Fidelity and diagnostic species concepts in vegetation classification in the Rocky Mountains, northern Utah, USA

The concepts of diagnostic species and fidelity have been used frequently in European phytosociology but rarely in North American vegetation classification. We developed a classification of the vegetation of a mountainous area of northern Utah and compared the diagnostic species approach with the indicator-species approach of habitat type classification sensu Daubenmire prevailing in the U.S. Interior West. A total of 157 forest and nonforested plots were described by vascular plants and basic environmental factors. Clustering with RandomForest classification and ordination reduced the original number of plots to 26 meaningful vegetation units. Of these 26 units, 22 were strong, having four or more faithful species. Four units were weak, having less than three faithful species. We identified species diagnostic of particular vegetation units that are potentially useful for recognition of these units in the field. We proposed vegetation types at the level of vegetation alliances and associations, and correlated them with environmental factors. We found our vegetation units to be more strongly associated with the underlying environment than major habitat types sensu Daubenmire. Our approach to classification has the potential to directly link vegetation with the physical environment and could be the basis for a substantial improvement of vegetation classification in the central Rocky Mountains

Humanized Rag1−/−γc−/− Mice Support Multilineage Hematopoiesis and Are Susceptible to HIV-1 Infection via Systemic and Vaginal Routes

Several new immunodeficient mouse models for human cell engraftment have recently been introduced that include the Rag2−/−γc−/−, NOD/SCID, NOD/SCIDγc−/− and NOD/SCIDβ2m−/− strains. Transplantation of these mice with CD34+ human hematopoietic stem cells leads to prolonged engraftment, multilineage hematopoiesis and the capacity to generate human immune responses against a variety of antigens. However, the various mouse strains used and different methods of engrafting human cells are beginning to illustrate strain specific variations in engraftment levels, duration and longevity of mouse life span. In these proof-of-concept studies we evaluated the Balb/c-Rag1−/−γ−/− strain for engraftment by human fetal liver derived CD34+ hematopoietic cells using the same protocol found to be effective for Balb/c-Rag2−/−γc−/− mice. We demonstrate that these mice can be efficiently engrafted and show multilineage human hematopoiesis with human cells populating different lymphoid organs. Generation of human cells continues beyond a year and production of human immunoglobulins is noted. Infection with HIV-1 leads to chronic viremia with a resultant CD4 T cell loss. To mimic the predominant sexual viral transmission, we challenged humanized Rag1−/−γc−/− mice with HIV-1 via vaginal route which also resulted in chronic viremia and helper T cell loss. Thus these mice can be further exploited for studying human pathogens that infect the human hematopoietic system in an in vivo setting

Pocket Guide to Sagebrush

This guide is written for anyone interested in learning more about sagebrush species and habitats. The introduction provides descriptions of some of the remarkably diverse sagebrush communities in western North America. The purpose of this guide is to give identifying characteristics and range maps for 18 species of sagebrush, encompassing 27 different kinds (including subspecies and hybrids). More detailed information can be obtained from the taxonomic and ecological treatises mentioned, and it is our hope that this guide will stimulate further examination of species and their habitats. Appendices at the back of the book provide a list of names in common use, with citations and synonyms. Taxonomy follows the recent treatment for the Flora of North America (Shultz 2006) and a monograph of sagebrush (Shultz 2009)

Vegetation Zones in the Bonneville Basin

For the purpose of vegetation classification, the Intermountain region has been variously defined as comprising a number of phytogeographic units (Cronquist et al., 1972). Of these, the Bonneville basin forms the largest floristic section in the Intermountain region (Holmgren, 1972). The Bonneville basin floristic section includes mountain ranges peripheral to the lake bed and covers 38,500 mi2 of land surface. At its highest level, Lake Bonneville covered 19,940 mi2 and was the largest of the Pleistocene lakes in the Great Basin. Even today, ..

A new species of Hackelia (Boraginaceae) from Utah

Hackelia ibapensis, a new species of Boraginaceae (Subfamily Boraginoideae, Tribe Eritrichieae) from the Deep Creek Range of Utah is described and illustrated

Artemisia L.

The second edition of The Jepson Manual thoroughly updates this acclaimed work, the single most comprehensive resource on California\u27s amazingly diverse flora. The Jepson Manual, second edition, integrates the latest science with the results of intensive fieldwork, institutional collaboration, and efforts of hundreds of contributing authors into an essential reference on California\u27s native and naturalized vascular plants