Microhabitat affinities of Gambel oak seedlings

Previous work suggested that Gambel oak seedlings are rare in the northern parts of its range in Utah where summer rainfall is relatively low but should be abundant in southern parts of the range where summer rainfall is usually high. Gambel oak grades from a relatively minor component of a ponderosa pine/mixed conifer assemblage in the south to a virtually monotypic formation in the north, where it exists as long-lived clones.   Quadrat analysis in Arizona and New Mexico, within the oak zone, revealed a seedling density ranging from 120 to 1320 per hectare. We found a significant tendency of seedlings to be located on the NE (cool, shady) side of sheltering objects in the environment. Mature ponderosa pine ranged in density from ca 40 to 500 stems per hectare, whereas mature Gambel oak ranged from ca 10 to 20 genets per hectare with ca 1 to 7 ramets per clone. These results support our previous conclusion that Gambel oak in northern Utah probably became established as a minor component of a mixed pine/oak woodland at a time in mid-Holocene when summer rainfall was much higher than today.     

Cedar Hollow, an early Holocene faunal site From Whidbey Island, Washington

Coastal erosion at central Whidbey Island reveals a cross-section view of dune sands that contain the only known record of animals that inhabited the Pacific Northwest coast during the early Holocene. Mammal fossils include bones and teeth of deer, wolf, brown bear, and several species of rodents. A deer vertebra from basal beds yielded a 14 C age of 8840 ± 50 yr BP. The faunal diversity suggests that the region was repopulated relatively quickly following the final retreat of the Cordilleran sheet. This paleofauna was quite different from that of the late Pleistocene, when the region was inhabited by mammoth, musk oxen, giant sloth, and other large mammals. Avian remains include hawks, geese, and seabirds, 3 groups that occupied quite different ecological niches. Early Holocene bird fossils from Whidbey Island are dissimilar to late Pleistocene avifaunas from inland sites in California and Oregon, evidence that the coastal environment offered habitat conditions quite unlike those of interior wetlands.     

Compositional similarity within the oakbrush type in central and northern Utah

Indices of similarity were used to evaluate the similarity of oakbrush stands throughout the Uinta National Forest and to compare oak communities in central and northern Utah. Results show that Gambel oak stands in central Utah differ significantly among themselves in respect to quantitative aspects of the vegetation. Those differences can be correlated with elevation, slope exposure, and fire history. Nevertheless, there is currently inadequate justification for recognizing more than one habitat type for the species in the study area. There is a need to develop a model capable of predicting growth rate of oak on specific sites.     

Investigating the influence of habitat type and weather conditions on the population dynamics of land snails Vertigo angustior Jeffreys, 1830 and Vertigo moulinsiana (Dupuy, 1849). A case study from western Poland

The conservation of land snails has become an urgent issue because of the current global decline of this group. Detailed knowledge of population dynamics is needed to develop an appropriate strategy for conservation. We investigated the population dynamics of two threatened European land snail species: Vertigo angustior and Vertigo moulinsiana. Although the species may be found at the same site, V. moulinsiana is more tolerant of wetter conditions than is V. angustior. Abundance data for the two species were collected at two sites (one drier and one wetter) in western Poland biweekly during the spring and summer months in 2008 and 2009. In the drier year, snail abundance was similar between the drier and wetter sites. In the wetter year, snail abundances were generally higher than in the dry year, except that the inundation-intolerant V. angustior became less abundant at the wetter site. We conclude that weather affects different species differently and therefore should be considered along with the habitat features in interpreting survey results for land snails.     

Winter nutrient content and deer use of gambel oak twigs in north central Utah

We examined winter nutritional quality of current-year bud and stem tissues from burned and unburned stands of Gambel oak ( Quercus gambelii Nutt.). Nutritional analyses were based on the amount of forage consumed by wintering mule deer. Deer use along the Utah Valley foothills averaged 6.25-10.7 cm of current-year growth. Of the tissues examined, post-fire bud tissue had the highest nutrient content, with a mean of 9.51% crude protein, 0.19% phosphorus, and 34.0% in vitro digestibility. Composite values (bud + stem) for unburned stands were slightly higher in crude protein and phosphorus and lower in digestibility than those reported in previous studies. Nutrient values from burned stands were significantly higher than those of unburned stands for all three measures. Tannin content of the burned-area regrowth was also higher. Overall forage value of Gambel oak to wintering mule deer is relatively low.     

Late quaternary plant zonation and climate in southeastern Utah

Plant macrofossils from packrat middens in two southeastern Utah caves outline development of modern plant zonation from the late Wisconsin. Allen Canyon Cave (2195 m) and Fishmouth Cave (1585 m) are located along a continuous gradient of outcropping Navajo Sandstone that extends from the Abajo Mountains south to the San Juan River. By holding the site constant, changes in the floral composition for a plot of less than one hectare can be observed, even if sporadically, over tens of millennia. At Allen Canyon Cave, Engelmann spruce-alpine fir forest was replaced by the present vegetation consisting of pinyon-juniper woodland on exposed ridgetops and cliffside stands of Douglas fir, ponderosa pine, and aspen. Xerophytic woodland plants such as pinyon, plains prickly pear, and narrowleaf yucca arrived sometime in the middle Holocene between 7200 and 3400 B.P. At Fishmouth Cave, Utah juniper in Holocene middens replaced blue spruce, limber pine, Douglas fir, and dwarf and Rocky Mountain junipers in late Wisconsin samples. Disharmonious associations for the late Wisconsin occur only at the lower site with the xerophytes Mormon tea, plains prickly pear, and narrowleaf yucca growing alongside subalpine conifers. One possible explanation involves the late Wisconsin absence of ponderosa and pinyon pines from the Colorado Plateaus. Released from competition at their lower limits, subalpine conifers were able to expand into lower elevations and mix with xerophytic plants found today in understories of pinyon-juniper and ponderosa pine woodlands. Quantitative climatic estimates are derived for the late Wisconsin by applying vertical gradients for temperature and precipitation to the amount of vegetation depression. The Fishmouth Cave sequence indicates a minimum lowering of 850 m for blue spruce, limber pine, and dwarf juniper. A depression of at least 700 m for Engelmann spruce and alpine fir is suggested for the Allen Canyon locality. Use of conservatively low gradients for stations below 2080 m yields a 3–4 C cooling from present mean annual temperature and 35 to 60 percent more rainfall than today. Steeper gradients associated with more mountainous terrain suggest a 5 C lowering in temperature and up to 120 percent increase over modern precipitation.        

Factors affecting selection of winter food and roosting resources by porcupines in Utah

Ecological and phytochemical factors potentially affecting winter dietary discrimination by porcupines ( Erethizon dorsatum ) in the mountain brush zone of Utah were studied. Porcupines utilized gambel oak ( Quercus gambelii ) as their primary winter food and roosting resource. Big-tooth maple ( Acer grandidentatum ) was the most common tree species in the study area but was rarely utilized by porcupines. Conifer species were used as a food and roosting resource significantly less often than they occurred in the study area, despite thermal advantages provided by their relatively dense canopies. Oak feed trees were successfully separated from conifer feed trees by discriminant analysis 100% of the time. Oak trees were correctly classified as feed and nonfeed trees 71% of the time. Gambel oak contained higher amounts of crude protein, fiber, and tannins, but was lower in either extract fractions and fatty acid content than conifers. A layer of adipose tissue used as an energy reserve by porcupines may have relaxed energy intake demands sufficiently to permit them to concentrate on a diet of oak tissue, which is high in protein, rather than a high-fat conifer diet. A diet relatively high in protein may have facilitated digestion of food material high in fiber. Temperature did not affect selection of tree species for roosting. Rock and snow caves were utilized infrequently and the study population ranged widely. Three of 15 study animals were eaten by predators.     

Full-glacial shoreline vegetation during the maximum highstand at Owens Lake, California

Owens Valley, California, was markedly different during the Wisconsin glacial stage from what it is today. Alpine glaciers bounded the Sierra Nevada, and pluvial Owens Lake reached highstands and overflowed its natural basin. We analyzed three layers from two packrat middens, dated to ca 23,000-14,500 yr BP, obtained from Haystack Mountain (1155 m) only 10 m above and Juniperus osteosperma ) and single-needle pinyon pine ( Pinus monophylla ) woodland existed at the site. In the layers dated to ca 17,500 and 16,000 yr BP, macrofossils document the presence of Rocky Mountain juniper ( Juniperus scopulorum ), a species that no longer occurs in California. It is suggested that meltwater from the retreating glacial ice inundated the Owens River Lake chain causing pluvial Owens Lake to reach its highstand. This caused an increase in effective moisture, due to high groundwater, allowing the mesophytic Rocky Mountain juniper to exist at the site.     

A Late-Pleistocene / Holocene biotic community from Marmot End Alcove, Escalante River Basin, Colorado Plateau, USA

Skeletal remains of the extinct mountain goat Oreamnos harringtoni and Marmota (marmot), an extralimital species, were recovered from Marmot End Alcove along with remains of montane plants that included Pseudotsuga menziesii (Douglas-fir), Picea (spruce), Pinus flexilis (limber pine), and Juniperus communis (common juniper). The alcove is located in Harris Wash, a semiarid tributary in an unstudied portion of the Escalante River Basin on the Colorado Plateau in southern Utah. A Marmota incisor tooth and montane plant needles returned late Pleistocene AMS dates ranging from 12,300 yr BP to 15,600 yr BP.     

Habitat requirements for Erigeron kachinensis , a rare endemic of the Colorado Plateau

Erigeron kachinensis is a rare endemic of the Colorado Plateau in southeastern Utah. This perennial composite grows in small, isolated populations at seeps and alcoves arising along canyon walls in Cedar Mesa Sandstone substrates. Characteristics of six Erigeron kachinensis sites in Natural Bridges National Monument, San Juan County, Utah, were studied to determine habitat requirements for this species. Sites were analyzed with respect to geology, soil chemistry, physical properties, and vegetational characteristics. The alcoves studied were very saline, often with soil surfaces covered with a white crust of salt. Living cover was enhanced by perennially moist soils, diminished amounts of solar radiation, soil salinity, and above-average amounts of available soil phosphorus. Kachina daisy vegetative growth appears to be favored by these same abiotic factors. The most commonly associated plant species on E. kachinensis sites were Aquilegia micrantha, Calamagrostis scopulorum, Zigadenus vaginatus, and Erigeron kachinensis . These species and the daisy accounted for more than 75% of the total living cover in the alcoves studied. A principal components analysis procedure was developed for evaluating site suitability for Erigeron kachinensis . This daisy has been successfully introduced to a site selected using that model.     

Bole volume growth in stems of Quercus gambelii

Shrub-form and tree-form Gambel oak ( Quercus gambelii ) stands contain a potentially significant fuelwood resource. Information on their growth characteristics can form a basis for future stand management. Stem analyses showed that height growth of shrub-form stems essentially ceased after age 50, while tree-form stems continued to increase in height until approximately age 100. Both stem forms continued to increase in basal area and volume at a relatively constant rate as the stems increased in age and size. Increases in all size measures were substantially greater in tree-form stems than in shrub-form stems. Mean bole volume for tree-form stems at age 100 was over 16 times that of shrub-form stems. Sprouts from tree-form stands would reach minimum size for fuelwood marketing in approximately 45 years.     

An Irvingtonian species of Brachylagus (Mammalia: Lagomorpha) from Porcupine Cave, Park County, Colorado

Brachylagus is currently a monotypic genus of uncertain origins and known only from Holocene and late Rancholabrean. A new species of leporid is described from the early and middle Pleistocene (Irvingtonian) deposits of Porcupine Cave, Park County, Colorado. Stratified deposits of the Pit and the Velvet Room, 2 localities within Porcupine Cave, have been dated biochronologically and paleomagnetically fro the middle Irvingtonian and early to middle Irvingtonian, respectively. Brachylagus coloradoensis sp. nov., is characterized by its conserved p3 enamel patterns which are intermediate between B. idahoensis and Hypolagus, and its size which is slightly larger than that of B. idahoensis . This suggest a possible ancestral relationship between Hypolagus and Brachylagus .     

The non-marine Crustacea of Antarctica and the Islands of the Southern Ocean: biodiversity and biogeography

A total of 101 verified species and eight ordinal taxa represent the non-marine Crustacea on Antarctica and the islands of the Southern Ocean. The largely terrestrial Isopoda and Amphipoda are confined to some sub-Antarctic and cool temperate islands while the predominantly freshwater Anostraca, Anomopoda, Copepoda (=Calanoida, Cyclopoida, Harpacticoida) and Ostracoda (Podocopida) occur throughout the region. Holocene sea-level rises fragmented freshwater and terrestrial species ranges on New Zealand, Auckland, Campbell, and possibly other South Pacific islands, leaving a legacy of vicariant taxa. Tertiary species probably survived Pleistocene glaciation in aquatic refugia on the New Zealand/South Pacific, Falkland, Crozet and Kerguelen archipelagoes, but there are no valid records of Tertiary Antarctic Crustacea. All 40 Continental and Maritime Antarctic freshwater records can be ascribed to the historic introduction of anthropogenic aliens, Holocene immigration of colonists, returning re-colonists and marine species 'marooned' in epishelf and other coastal lakes.     

XLIX.—A list of New Zealand Heteroptera with the description of a remarkable green Aradid representing a new genus

Summary

Christchurch Harbour is the lagoonal estuary of the Rivers Avon and Stour. Due to the low tidal range much of it remains submerged at low water. The microfauna living on the bottom sediment includes Foraminiferida and Thecamoebina. The latter are normally restricted to the lower reaches of rivers but when low salinity conditions prevail in the lagoonal part of the estuary they have a wider distribution. It is shown that a number of species will tolerate brackish water if the calcium content is less than 1 mg-atom/l. Most species show seasonal changes in abundance related partly to temperature changes. It is suggested that fossil Thecamoebina may be more common than has previously been recognized, especially in Pleistocene and Holocene deposits, and that they would be useful paleoecological indicators.     

Late Quaternary arthropods from the Colorado Plateau, Arizona and Utah

Late Quaternary-age arthropods were recovered from dry cave deposits and packrat middens located in the Grand Canyon, Canyonlands, and Glen Canyon region of the Colorado Plateau. This Quaternary data resource has not been analyzed before from the Colorado Plateau national parks. Radiocarbon dates on the various deposits containing arthropods range from 1510 to 30,660 yr B.P. The fossil assemblages yielded 57 identified taxa of insects, arachnids, and millipedes, including 15 taxa taken to the species level. The information from the fossil insect record of the Colorado Plateau is not yet sufficiently detailed to permit precise paleoenvironmental reconstructions. However, preliminary conclusions suggest a cooler, moister climatic regime during the late Wisconsin glacial and a mosaic of vegetation types, such as grassland and shrubby communities, unlike the present vegetation at the localities.     

Snake Creek Burial Cave and a review of the Quaternary mustelids of the Great Basin

Snake Creek Burial Cave (SCBC), east central Nevada, is a unique paleontological deposit. The cave is the first natural trap excavated in the Great Basin and one of the few localities describing a valley-bottom community. The recovery of extinct Camelops sp. (camel) and Equus spp. (horse), in addition to radiometric dates, indicates at least some of the deposits to be of late Pleistocene age. Eight mustelid species have been identified from SCBC, including three species not previously reported from the late Rancholabrean of the Great Basin: Mustela nigripes (black-footed ferret), M. nivalis (least weasel), and Gulo gulo (wolverine). A review of late Pleistocene deposits indicates that there are more species of mustelids recovered from Snake Creek Burial Cave than from any other locality in the Great Basin.     

Biodiversity and biogeography of non-marine Mollusca on the islands of the Southern Ocean

There are no terrestrial and freshwater molluscs associated with Continental nor Maritime Antarctica. The malacofaunas of the cool-temperate and sub-Antarctic islands of the Southern Ocean are extremely depauperate, comprising a mere 68 site-records of 51 species from 27 genera in 13 families. The South Atlantic records are confined to the Falkland Islands, which harbour nine species (one bivalve, five pond snails and three terrestrial aliens), and South Georgia, where there is one Notodiscus sp. (Charopidae). The fauna of the South Indian Ocean islands of Prince Edward, Crozet, Kerguelen and Heard, comprises two alien slugs and endemic Notodiscus hookeri (Charopidae). The majority of species occur on the South Pacific Ocean Islands of Macquarie, Campbell, Auckland, Snares, Antipodes, Bounty and Chatham to the south and east of New Zealand. The Chatham fauna is dissimilar to that on the other South Pacific Islands, though both represent vicariant remnants of common South Pacific Is./New Zealand Athoracophoridae, Charopidae and Punctidae. There is, other than the broad South Indian Ocean distribution of Notodiscus hookeri, little evidence of Holocene dispersal and colonization. Indeed the Southern Ocean is an effective barrier and the different regional (South Atlantic/Indian/Pacific) faunas are principally vicariant and derived from local survivors of Pleistocene glaciation.     

Late Pleistocene microtine rodents from Snake Creek Burial Cave, White Pine County, Nevada

A total of 395 microtine rodent specimens recovered from Snake Creek Burial Cave (SCBC) are referred to Microtus sp. and Lemmiscus curtatus . Radiocarbon and Uranium series dates indicated an age for these fossils of between 9460 ± 160 yr. B.P. and 15,100 ± 700 yr. B.P. The sample of lower first molars of Lemmiscus includes 4-, 5-, and 6-closed triangle morphotypes. Earlier reports of the 4-closed triangle morphotype are from Irvingtonian deposits in Colorado, Nevada, and New Mexico and from early Rancholabrean deposits in Washington. The morphotype is not known in living populations of Lemmiscus . SCBC specimens constitute the youngest record of the 4-closed triangle morphotype and are the only specimens reported from the late Rancholabrean. The time of disappearance of Lemmiscus with this molar morphology is unknown, but populations with this morphotype possibly became extinct at or near the end of the Pleistocene.