Habitat relationships of saltcedar ( Tamarix ramosissima ) in central Utah

Nineteen study sites were established in areas infested with saltcedar bordering Utah Lake in central Utah. Saltcedar cover on the sites averaged 57% but varied widely from community to community. Seventeen soil factors were measured relative to the stands studied. Cover of saltcedar was regressed against the different soil factors, but no patterns were detected. Saltcedar functioned equally well at all levels of each gradient studied and appeared able to accommodate wide variations in all factors studied. It is suggested that saltcedar has evolved a general-purpose genotype that contributes to its being a vigorous and troublesome weed. Criteria as to why it is such an aggressive weed are listed.     

Effects of salinity on establishment of Populus fremontii (cottonwood) and Tamarix ramosissima (saltcedar) in southwestern United States

The exotic shrub Tamarix ramosissima (saltcedar) has replaced the native Populus fremontii (cottonwood) along many streams in southwestern United States. We used a controlled outdoor experiment to examine the influence of river salinity on germination and first year survival of P. fremontii var. wislizenii (Rio Grande cottonwood) and T. ramosissima on freshly deposited alluvial bars. We grew both species from seed in planters of sand subjected to a declining water table and solutions containing 0, 1, 3, and 5 times the concentrations of major ions in the Rio Grande at San Marcia, NM (1.2, 10.0, 25.7 and 37.4 meq 1 -1 ; 0.11, 0.97, 2.37, and 3.45 dS m -1 ). Germination of P. fremontii declined by 35% with increasing salinity ( P = .008). Germination of T. ramosissima was not affected. There were no significant effects of salinity on morality or above- and belowground growth of either species. In laboratory tests the same salinities had no effect on P. fremontii germination. P. fremontii germination is more sensitive to salinity outdoors than in covered petri dishes, probably because water scarcity resulting from eavaportion intensifies the low soil water potential associated with high salinity. River salinity appears to play only a minor role in determining relative numbers of P. fremontii and T. ramosissima seedlings on freshly deposited sandbars. However, over many years salt becomes concentrated on floodplains as a result of evaporation and salt extrusion from saltcedar leaves. T. ramosissima is known to be more tolerant of the resulting extreme salinities than P. fremontii . Therefore, increases in river salinities could indirectly contribute to decline of P. fremontii forests by exacerbating salt accumulation on floodplains.     

Occurrence of Phaedactylum Tricornutum in the Great Salt Lake, Utah, USA

The diatom Phaedactylum tricornutum Bohlin forms blooms in the south arm of the Great Salt Lake, Utah, during cool months. This represents the first report of this taxon from Utah and the first from nonmarine waters in the United States.     

Relating soil chemistry and plant relationship in wooded draws of the northern Great Plains

Soils of the green ash/chokecherry habitat type in northwestern South Dakota were evaluated for 22 properties to determine whether any could be correlated with density of chokecherry ( Prunus virginiana ) and snowberry ( Symphoricarpos occidentalis ). Surface soils were moderately fertile, with high levels of all elements except phosphorus and nitrogen. Soils were fine textured with moderately high cation exchange capacity and saturation percentages. However, soils were nonsaline-nonalkaline with low amounts of exchangeable sodium. None of the soil properties showed good correlation with chokecherry and snowberry densities. Greatest correlations were found between each of the shrub species and grass.     

Waterfowl and shorebird use of surface-mined and livestock water impoundments on the Northern Great Plains

Cluster analysis and stepwise discriminant analysis were used to group waterfowl and shorebird use on water impoundments (bentonite, coal, livestock) on the Northern High Plains. Three bird-use categories—high, medium, and low—were delineated by these analytical procedures. Eleven physical, chemical, and biological parameters of impoundments were related to bird use; water area, nitrogen, and low basin slopes were found to be important parameters in estimating bird use on impoundments. Spring and summer were the best seasons for surveying waterfowl and shorebird water impoundment use.     

Association of black-tailed prairie dog colonies with cattle point attractants in the Northern Great Plains

In October 1991 we recorded all black-tailed prairie dog ( Cynomys ludovicianus ) colonies and cattle points in a 1248-km 2 study area in southwest North Dakota and southeast Montana. Cattle point attractants were defined as fabricated water tanks and long-term supplemental feed sites. We found that a signivicant number of prairie dog colonies encompassed or adjoined cattle point attractants ( p < .001). Prairie dog colonies associated with cattle point attractants were a mean distance of 1.0 km from the next nearest town. The existence of cattle point attractants may encourage prairie dog colonization. Conversely, refraining from using long-term cattle point attractants can discourage prairie dog colonization.     

Caligids (Copepoda: Caligidae) found on the bream (Acanthopagrus spp.) of Australia

Eleven species of parasitic caligid copepods were recorded from approximately 1000 specimens of four congeneric species of Australian bream. New species were described and previously recorded species redescribed where necessary. Those caligids recovered in large numbers were liberal in choice of host species and displayed a wide geographical range within Australia.     

Some parasites of paddlefish ( Polyodon spathula ) from the Yellowstone River, Montana

One species of copepod ( Ergasilus elongatus ), one trematode ( Diclybothrium hamulatum ), two nematodes ( Camallanus oxycephalus and Contracaecum sp.), and two cestodes ( Marsipometra hastata and M. parva ) were recovered from 17 paddlefish ( Polyodon spathula ) collected from the Yellowstone River, Montana, on 11 and 18 May 1973. The male paddlefish averaged 69.4 nematodes and 157.6 cestodes per infected fish while the females averaged 12.0 nematodes and 415.7 cestodes. The higher intensity of cestode infection in female paddlefish was attributed to their larger size and consequent greater intake of food resulting in more exposure to the cestode intermediate hosts ( Cyclops bicuspidatus ).     

Population variation of web-invading spiders (Theridiidae: Argyrodes spp.) on host webs in Guam,Mariana Islands,Micronesia

Most Argyrodes spiders live in the webs of other spiders as kleptoparasites, stealing food from the host and scavenging small prey from the web. We observed three species of Argyrodes from the Micronesian island of Guam to learn (1) if Argyrodes species differ in their use of host-species webs, (2) whether some Argyrodes species occur more often in certain habitats, (3) whether population size of Argyrodes is a function of web size, and (4) how the presence of congeners affects population size on a web. Argyrodes lived most often in the large, long-lasting orb webs of Argiope appensa and Cyrtophora mollucensis, and, rarely, in the smaller, less durable orb webs of Neoscona spp. and Leucauge spp. Argyrodes argentatus and Argyrodes sp. A frequently co-occurred in Argiope webs, but A. argentatus was more common in beach strand and open disturbed habitats, while Argyrodes sp. A was more common in shaded native forest. The abundances of A. argentatus and Argyrodes sp. A in Argiope webs and the abundance of Argyrodes sp. B in Cyrtophora webs were positively correlated with the areas of the webs' prey-catching surfaces. The abundance of A. argentatus was inversely proportional to that of Argyrodes sp. A on Argiope webs and to that of Argyrodes sp. B on Cyrtophora webs, suggesting interspecific avoidance.     

Flowers,faeces and cadavers: natural feeding and laying habits of flesh flies in Thailand (Diptera: Sarcophagidae,Sarcophaga spp.)

Baiting and flower watching mainly in forest habitats throughout Thailand (1997–2002) yielded 46 species of Sarcophaga Meigen. About 50% of the species are new to Thailand and several new to science. All 67 species of Sarcophaga so far reported from Thailand are listed and their taxonomic status and nomenclature updated. Emphasis on rearing (523 broods) ensured species identification through the male progeny of the otherwise mostly unidentifiable females, and allowed several new correct male–female associations, besides offering new insights into the flies' breeding strategies. Three natural larviposition habits were observed in the wild: (1) on faeces of carnivorous and omnivorous, but not herbivorous, mammals (coprobiodotic), e.g. S. africa (Wiedemann), S. albiceps Meigen, S. misera Walker; (2) on cadaver (necrobiodotic), e.g. S. krathonmai Pape and Bänziger, S. nathani (Lopes), S. saprianovae Pape and Bänziger; and (3) on both of them (amphibiodotic), e.g. S. dux Thompson, S. ruficornis (Fabricius). However, larvae of copro- and necrobiodotic species experimentally transferred to cadaver and faeces, respectively, also developed to normal adults. The unexpected laying choosiness between excrement or carrion in the wild is discussed, together with the role played by laying habits in deceptive pollination systems and myiases.     

Variation in populations of mine- and gall-forming Diptera and the growth form of their host plant,bracken (Pteridium aquilinum (L.) Kuhn)

Eight species of Diptera belonging to the families Anthomyiidae, Cecidomyiidae and Agromyzidae utilize bracken in different ways and show preferences for different types of bracken habitat. The annual and local variation found in populations of these mining and gall-forming herbivores in different sites in Southeast England over a four-year period are described. Possible reasons for the differences in distribution patterns are discussed, in terms of the growth and phenology of the host plant, resource availability and natural enemies.     

Aspects of the biology of the flathead chub ( Hybopsis gracilis ) in Montana

Mature flathead chubs ( Hybopsis gracilis ) were present in mid - July and mid - August collections from the Musselshell River, Montana. The estimated numbers of mature eggs present in eight females were 360&ndash;753 per female. The smallest mature female and male collected were 113 and 123 mm in total length, respectively. The male to female sex ratio in collections was about 1:1. Only small differences were detected among the length &ndash; weight relationships of males and females and samples taken from various seasons and localities in Montana. Observations on size groups, fish associates, and habitat characteristics of flathead chubs are presented. &nbsp;&nbsp;&nbsp;     

Fleas (Siphonaptera) in nests of boles ( Microtus spp.) in montane habitats of three regions of Utah

As a parallel study of a survey of fleas of trapped small mammals in montane southern Utah, we removed 77 adult fleas from 12 of 13 nests of voles ( Microtus longicaudus, M. montanus and M. richardsoni ) collected from montane meadows in the Abajo and La Sal Mountains, the Markagunt Plateau and Pine Valley Mountains, and the Uinta Mountains, May 1991-July 2002. Six species and subspecies of fleas parasitic on Microtus spp. were found, 1-3 species in each nest. Three specimens of the ubiquitous deer mouse ( Peromyscus spp.) flea Aetheca wagneri (Baker) were also found. We collected the following 7 taxa from the locations indicated: Catallagia decipiens Rothschild in 5 nests: Abajo and Pine Valley Mountains and Markagunt Plateau; Hystrichopsylla dippiei truncata Holland in 2 nests: La Sal and Uinta Mountains; H. occidentalis sylvaticus Campos & Stark in 5 nests: Pine Valley Mountains; Peromyscopsylla selenis (Rothschild) in 1 nest: Markagunt Plateau; A. wagneri in 2 nests: Abajo and Pine Valley Mountains; Megabothris abantis (Rothschild) in 5 nests: Abajo and Uinta Mountains and Markagunt Plateau; Malaraeus telchinus (Rothschild) in 2 nests: Abajo and Pine Valley Mountains. One preserved larva was identified as Hystrichopsylla prob. occidentalis sylvaticus , and 2 dead larvae, the only specimens found in nest 13, were identified as probably the same. Kane County is a new record for C. decipiens and P. selenis ; Kane and Summit Counties are new for M. abantis . Nest surveys can generally supplement rather than replace trapped-host surveys. Their main value is in population studies. They are also a source of larvae for morphology and taxonomy research.     

Emergence patterns of large stoneflies (Plecoptera: Pteronarcys, Calineuria, Hesperoperla ) in a Montana river

Emergents of Pteronarcys californica, Calineuria californica , and Hesperoperla pacifica were captured with replicated emergence traps at 3 sites along the banks of Rock Creek, Montana. Pteronarcys emergence in early June was short (88% of individuals in 6 d) and attained rates of 5 m -1 d -1 (shoreline distance) and cumulative densities up to 19 m -1 yr -1 . Calineuria emerged synchronously (89% in 9 d) 2 wk later at densities up to 7 m -1 d -1 and 40 m -1 yr -1 . The less numerous Hesperoperla (5 individual m -1 yr -1 ) had a longer emergence period partially coinciding with Calineuria Median males of Pteronarcys and Calineuria emerged 2-3 d before median females; protandry was not significant Hesperoperla . Sex ratios were female-biased in Pteronarcys and Hesperoperla but male-biased in Calineuria . Size trends through emergence were very weak although females showed a greater tendency towered larger size early in emergence.     

Variability among five riparian cottonwood ( Populus fremontii Wats.) populations: an examination of size, density, and spatial distribution

Various abiotic and biotic factors are known to affect tree size, including age, genetics, and environment. Knowledge of size variation within natural riparian tree populations has both ecological and restorative importance. We determined tree sizes, basal area densities, and spatial distributions of 5 Populus fremontii Wats. populations within the Rio Grande watershed in New Mexico. At each site 10 randomly spaced plots, perpendicular to the river and extending from the river to the end of the forest, were established. Diameter at breast height (DBH) and distance to the river were determined for 1803 trees within the 5 populations, and stand cover (measured as basal area [BA] per hectare) was determined for each population. Significant variation in tree size and basal area density existed among sites. Mean DBH per site ranged from 11.7 to 58.4 cm and differed significantly ( P P 2 ha -1 . Spatial distribution of trees in relation to the river also differed among sites. Mean distance from the river ranged from 50 to 353 m and differed significantly ( P P. fremontii populations may be influenced by differences in water availability across a site; trees farthest from water sources may experience greater water stress and, therefore, growth limitation. Increasing BA cover with increasing tree size indicated no real thinning of mature trees within a population. Recruitment and establishment of cottonwood seedlings and saplings was evident only at sites with newly formed floodplains. For these 5 populations tree size appeared to be affected by environmental factors.     

Reproductive status and continuity of taxa of the Simulium arcticum complex (Diptera: Simuliidae) at the Clearwater River, Montana (2007, 2008, and 2009)

We made 27 collections over nine years at the Clearwater River and conducted preliminary cytogenetic analysis on 232 individuals of the Simulium arcticum complex there. Based on these preliminary findings, we analyzed an additional 1825 larvae from Clearwater collections in 2007, 2008, and 2009 to investigate the reproductive statuses of the two prevalent taxa of the complex there and to determine whether cytogenetic diversity and frequency of types were similar from year to year. We describe a cytotype new to science and a potentially derivative cytotype of S. arcticum sensu stricto. We also determine that these two taxa are present in similar frequencies from year to year and are in genetic equilibrium, suggesting that they are not reproductively isolated. This study constitutes the fourth positive test of our Geographic Distribution/Taxon Age hypothesis.     

Transverse pattern of vegetation on avalanche paths in the northern Rocky Mountains, Montana

Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} The pattern of vegetation on avalanche paths has usually been ascribed to the damage done by snowslides. In the northern Rocky Mountains the pattern of herbs, shrubs, and small trees appears to be more complex than could be accounted for by avalanche magnitude and frequency. The vegetation on one path in Montana illustrates that the topography of the path is a factor in the distribution of species. Three zones exist across avalanche paths: an inner zone of herbs and suffrutescent shrubs occupying a ravine, which is snow covered longer than elsewhere; flanking zones of dense shrubs and trees with flexible stems; and an outer zone of less dense shrubs that is more xeric. The pattern of vegetation seems to be due to avalanche-related stress rather than damage. &nbsp;&nbsp;     

Pseudocrossidium obtusulum (Pottiaceae, Bryopsida) new to Montana with a key to North American apecies in the genus

The moss species Pseudocrossidium obtusulum (Lindb.) Crum & Anderson is reported for the state of Montana. Recent systematic of the genus Pseudocrossidium in North America is discussed.     

New records of Bathynellacea (Syncarida,Bathynellidae) in North America: three new species of the genus Pacificabathynella from Montana,USA

Three new species of the genus Pacificabathynella Schminke and Noodt, 1988 Schminke, H K and Noodt, W. 1988. Groundwater Crustacea of the order Bathynellacea (Malacostraca) from North America. J Crustacean Biol., 8(2): 290–299.  [Google Scholar] are described from groundwater aquifers in glaciated North America (Montana, USA). This is the first time that this genus, known previously only from the state of California, has been documented in Montana. Pacificabathynella and Paradoxibathynella Serban, 2000 Serban, E. 2000. Uenobathynella n.g., Parauenobathynella n.g., Morimotobathynella n.g., Nihobathynella n.g. et Paradoxibathynella n.g., Bathynellinae du Japón (Bathynellidae, Bathynellacea, Podophallocarida). Travaux Inst Spéol “Émile Racovitza”, 36: 3–61.  [Google Scholar] are the only genera that show sexual dimorphism in thoracopod VI. Pacificabathynella kalispellensis sp. nov. has several unique features: the setal formula of the antenna (0/2+exop/3/12/6/8/5); the setal formula of the maxilla (7/4/7/6); the presence of an epipod on thoracopod II; tufts of setulae and abundant setae on the basipod and endopod of thoracopods I to V; the epipod of thoracopod VIII female three times longer than the basipod; three smooth setae on the exopod of the female thoracopod VIII; eight spines on the endopod of the uropod and the endopod longer than the sympod, whereas the opposite is typical. Pacificabathynella stanfordi sp. nov. has several unique features: only five setae on the exopod of thoracopods II to VII, while six setae are common in the genus; only six setae on the second segment of the first pleopod; five spines on the endopod and seven setae on the exopod of the uropod. Pacificabathynella ruthae sp. nov. is the largest species and has several unique features: antennule equal in size to the antenna, whereas in the rest of the species of the genus the antenna is larger; the projection of the inner lobe of the male thoracopod VIII is bidentate and there are six spines on the endopod and nine setae on the exopod of the uropod. The three new species have slight differences in the pars molaris of the mandible and in thoracopod VIII of males, and there are other minor differences between the females and the species Pacificabathynella sequoiae. The new taxa, together with the new genus Montanabathynella described separately, represent a 30% increase in North American taxa. Considering the glaciated landscape and the fragmented nature of alluvial aquifer habitat, we believe that there is a profound lack of critical knowledge of the biogeography and biodiversity of syncarids in North America.