The influence of western hemlock and western redcedar on microbial numbers,nitrogen mineralization,and nitrification

Summary Microbial numbers in the forest floor and mineral soil (Al horizon) under large individual western hemlock (Tsuga heterophylla) and western redcedar (Thuja plicata) trees were compared. The lower pH and base saturation of hemlock samples was associated with higher fungal spore counts while cedar samples had higher total microbial counts and populations of ammonium oxidizing bacteria. Nitrogen mineralization rates were greater in laboratory incubations of hemlock soil but nitrification was only observed in incubations of cedar soil. These differences in nitrogen mineralization and nitrification are aspects of species-specific nutrient cycling regimes.     

The chimpanzee of Filabanga,western Tanzania

The chimpanzee (Pan troglodytes) of western Tanzania is found in one of the driest habitats of this species where openland vegetation, especially theBrachystegia, Julbernardia, andIsoberlinia woodlands, is dominant, while the evergreen or semi-evergreen rain forests (the riverine forests) are less developed, being confined to river basins. The chimpanzee seems to adapt to this dry country better than any of the other forest primates living there. The results of the study in Filabanga indicate that there are some methods of adaptation which enable the chimpanzee to survive in this harsh environment.

1. The chimpanzee uses openland vegetation to a comparatively large extent. TheBrachystegia bussei woodland especially, is utilized as a habitual nesting place and doubtless as an important feeding place.
2. In the Masito Hills, which comprises Filabanga, the localities where food is abundant change seasonally. The chimpanzees migrate over a wide range, estimated to be between 200 and 400 square kilometers, from an area where food has become scarce to an area where food is plentiful.
3. Areas where food is plentiful are shared by two or more unit groups of chimpanzee.
4. The grouping patterns of the chimpanzee enable it to utilize both the areas where food is scarce and those where it is abundant.

     

Blame it on Southern,but it's a western blot

Edwin M. Southern is a professor emeritus at the University of Oxford. He is perhaps best known for development of the “Southern blot” (Dr. Southern was at the University of Edinburgh when he wrote his landmark paper). The Southern blot provided a scientific breakthrough by allowing scientists to detect a particular DNA sequence without first purifying it from the rest of the genome; the basic method involves the transfer of the DNA to a membrane, followed by detection with a specific probe. Although few people perform Southern blots as originally carried out by Southern, due in part to the more recent technique of the polymerase chain reaction, the basic concept continues to play an important role in molecular biology.     

Limnological survey of Lake Amvrakia, western Greece

Limnological characteristics of lake Amvrakia, a deep warm monomictic and sulphate lake in western Greece, are presented. A set of physical and chemical variables were monitored for one year cycle (October 1988–September 1989). Phytoplankton community structure and biomass are given for the entire depth of the water column. The trophic status of the lake is compared to that of other temperate and tropical lakes.     

Brothers,friends, and enemies: averting intimacy on Facebook in western India

Anthropological studies of the internet have traced the emergence of new forms of intimacy in various arenas of life, including friendship. Drawing upon an ethnography of Facebook and its use among young lower-middle-class men in Pune, Maharashtra, western India, the article investigates the discourse of friendship young men deploy on the platform. Although moulded in the image of their intimate friendships, their interactions with one another on-screen function to perform the ties of kinship. The distinctions young men draw between Facebook and their friendships off-screen reveal the particular forms male friendships take, the egalitarian ideal they contain, the privacy they require, and the care taken to foster them. Through examining the tensions between local articulations of intimacy and the publicity Facebook affords, I show how possibilities for online friendship, rather than being propelled by their freedom from external social conditions, are limited by the constraints of kinship.     

Patch type influences on regeneration in a western Pennsylvania, USA, catastrophic windthrow

We investigated the influence of differing patch types on the germination, growth, and survival of two species of tree seedlings in a catastrophic, old‐growth forest windthrow. We documented environmental conditions, and experimentally introduced seeds, transplanted seedlings, and manipulated litter and herbivore access to determine the effects of patch types during initial forest regrowth.
Among patch types defined by substrate condition and exposure, we found significant differential influence of patch type on germination of seeds of a common colonizer, Betulaalleghaniensis. Patch types that provided exposed mineral soil allowed greater germination than other patch types, regardless of light availability. Germination of Acerrubrum varied among patch types in a fashion similar to that of B. alleghaniensis, although differences among patch types were not significant.
Litter can also be the basis of patch classification. Both type and amount of litter significantly influenced emergence of seedlings, with broad‐leaf litter (in amounts typical of intact forest) producing greater inhibition of emergence than amounts of conifer needles typical of intact forest. Survival and performance of fenced and unfenced Acerrubrum seedlings transplanted into different patch types reflected influences of both herbivory and competition with existing vegetation.
Survival was lowest where the Acer seedlings were most apparent to mammalian herbivores. Growth of Acer seedlings was greater when they were protected from herbivory and free of competition from surrounding vegetation.
These findings demonstrate that patch types offer different suitability as regeneration microsites during early tree life history stages. Because these patch types are common and easy to recognize, the differences in species’ responses may be sufficiently general to apply in other disturbances of this type. If general species responses to patch types can be combined with knowledge of propagule abundance and patch abundance, it could provide a basis for improved understanding of post‐disturbance regeneration, via patch influences.     

Effects of fire on sward structure and grazing in western Serengeti, Tanzania

In Serengeti fire is used as a management tool to improve the forage quality for large herbivores. However, little is known of the effects of fire on grazing resources particularly sward structure, its influence on herbivore forage patch selection and utilization to the relative amount of phytomass consumed in burnt and nonburnt patches. From September 2003 to July 2004, consumption of phytomass by large herbivores was assessed with eight samplings in six grassland sites in the Western Corridor in Serengeti National Park. Each site had burnt and nonburnt plots. Movable cages were used to exclude grazing between samplings and plant material harvests were used to assess phytomass and sward structure changes in time. Nonburnt grasslands had consistently larger phytomass at all sampling events whereas the ratio for live leaf/total phytomass was higher in burnt grassland at early postfire stages, but declined later in the season. Moreover, periodic consumption of both total phytomass and different phytomass components shifted between burnt and nonburnt grasslands, but there were also large site-specific responses. The shift appears to be related to the balance between the amount of phytomass available and the quality of the forage in terms of the ratio between live and total phytomass. The study highlights the significance of maintaining mosaics of burnt and nonburnt areas with an adequate provision of forage amount and quality all year round.     

The effect of photoperiod on walking, feeding, and oviposition in the western flower thrips

The western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), is a major pest in glasshouses, where light and photoperiod are often manipulated to grow crops. The effect of five photoperiods (L0:D24, L6:D18, L12:D12, L18:D6, and L24:D0) on the behaviour of adult females was investigated in the laboratory at 25 °C. The amount of walking, pollen consumption, and oviposition all increased with increasing photophase. The three behaviours occurred at a low rate in continuous darkness, and are therefore not exclusively diurnal. Three out of 16 thrips (19%) showed weakly rhythmic walking activity in continuous darkness, with an average circadian period of 25.3 ± 1.5 h. It is proposed that the length of the photophase determines the amount of nutrient intake, which in turn determines oviposition rate and thus affects population increase.     

Predation on fish eggs by white perch,Morone americana,in western Lake Erie

Synopsis The white perch,Morone americana, is an east coast estuarine species that invaded Lake Erie in the 1950's, but did not increase in abundance until the mid 1970's. We studied its distribution and feeding during spawning in the Sandusky River, Ohio in 1981–1983. White perch were present in the area from early April through May, but abundance was highest on bedrock riffles about 45 km upstream from Lake Erie. Spawning activity peaked in the last week of April when temperatures approached 18°C. White perch collected in early April had eaten walleye,Stizostedion vitreum vitreum, eggs. As spawning activity of white perch increased, feeding activity declined, and most fish collected during late April contained no food. Egg predation increased again in May, but the eggs eaten then were those of white bass,Morone chrysops, white perch, and possibly other species. We have no evidence that egg predation by white perch has affected walleye or white bass recruitment, but it could become a problem if white perch continue to increase in abundance.     

Post-Hypsithermal plant disjunctions in western Alberta, Canada

Aim Evaluate the hypothesis that nine disjunct vascular plant species along the eastern slopes of the Rocky Mountains and in the Peace River District of west‐central Alberta represent remnants of more southerly vegetation that occupied these areas during the Holocene Hypsithermal (9000–6000 yr bp ). Alternatively, these plants represent populations that became established because of independent chance dispersal events. Location This study focuses on the area east of the Rocky Mountain Continental Divide in the Province of Alberta and the State of Montana in western Canada and USA, respectively. Methods Disjunct species were identified and their distributions mapped based on a review of occurrence maps and records, botanical floras and checklists, herbaria specimens, ecological and botanical studies, and field surveys of selected species. A disjunct species was defined as a plant population separated from its next nearest occurrence by a distance of > 300 km. Evaluation of the hypothesis was based on a review of published and unpublished pollen stratigraphy and palaeoecological studies. The potential geographical distribution of Hypsithermal vegetation was based on modern regional‐based ecosystem mapping and associated monthly temperature summaries as well as future climatic warming models. Results The hypothesis was compatible with Holocene pollen stratigraphy, Hypsithermal permafrost and fen occurrence, and palaeosol phytolith analyses; and future global climatic warming models. Modelled regional Hypsithermal vegetation based on a 1 °C increase in July temperatures relative to current conditions, indicated that much of the boreal forest zone in Alberta could have been grassland, which would explain the occurrence of Prairie species in the Peace River District. This amount of latitudinal vegetation shift (6.5°) was similar to an earlier Hypsithermal permafrost zone location study. An equivalent shift in vegetation along the eastern Cordillera would have placed south‐western Montana‐like vegetation and species such as Boykinia heucheriformis (Rydb.) Rosend. and Saxifraga odontoloma Piper within the northern half of the Rocky Mountains and foothills in Alberta, which represents the location of modern‐day disjunct populations of these species. Main conclusions Warmer and drier climatic conditions during the Holocene Hypsithermal resulted in the northward displacement of vegetation zones relative to their current distribution patterns. Most of Alberta was probably dominated by grasslands during this period, except the Rocky Mountains and northern highlands. Modern‐day species disjunctions within the Rocky Mountains and Peace River District as well as more northerly areas such as the Yukon Territory occurred when the vegetation receded southward in response to climatic cooling after the Hypsithermal. Wind dispersal was considered an unlikely possibility to explain the occurrence of the disjunct species, as most of the plants lack morphological adaptations for long distance transport and the prevailing winds were from west to east rather than south to north. However, consumption and transport of seeds by northward migrating birds could not be excluded as a possibility.     

Middle Jurassic Porifera from Kachchh, western India

From the Late Bathonian sponge biofacies at Jumara Dome, Kachchh (western India) 11 species of ‘lithistid’, hexactinellinid and calcarean sponges are described. New taxa are the order Sigmatospirida, the genusJumarella, and the speciesJumarella astrorhiza, Mastosia rhytidodes, Radicispongia kraspedophora, andHexactinella prisca. The diverse sponge assemblage is associated with a rich fauna of epibenthic bivalves and brachiopods and formed meadows on fine-grained carbonate substrates. The sponge meadows grew on a carbonate ramp at the lower end of the photic zone, in quiet waters below storm wave base. The rate of sedimentation exceeded that of sponge production. This prevented the development of reef-like bodies. In contrast to Mesozoic sponge reefs, growth of the sponge meadows appears to have been confined to the regressive phases of small transgressive-regressive cycles.     

Plio-Pleistocene cercopithecids from Kanam East, western Kenya

This paper describes cercopithecid craniodental and postcranial fossils recovered by L. S. B. Leakey at Kanam East, Kenya during the early 1930s. These fossil monkeys have been generally assumed to have been derived from early Pliocene horizons, but their exact geographical and stratigraphical provenience is unknown. Although the question of the evolutionary significance of these specimens must await the recovery of more securely dated material from Kanam East, some general conclusions can be drawn concerning their taxonomic affinities and paleobiology. Based on comparative studies of the craniodental material, at least three extant genera are represented—Colobus,Lophocebus, andCercopithecus. The postcranial fossils include a number of hindlimb specimens, as well as the manubrium of a sternum and a caudal vertebra. Identification of the postcranial remains to particular genera is not possible, but they are similar in morphology to modern arboreal and semiterrestrial cercopithecid monkeys of small to medium size. It is evident that Kanam East had a diverse cercopithecid community, similar to those found today in forested and woodland habitats, and this may be of some significance in reconstructing the paleoecology of the site. Because the fossil record of most extant cercopithecid genera is rather sparse at Plio-Pleistocene sites in Africa, Kanam East represents one of only a few sites that has yielded material that can be assigned toColobus,Lophocebus, orCercopithecus. The fossil monkeys from the site, therefore, provide additional evidence to help reconstruct the paleobiology, as well as the patterns of species diversity and community structure that characterized the cercopithecid radiation during the Plio-Pleistocene.     

Agriculture,weeds and the western isles machair

Summary

The Western Isles machair has supported agriculture for 5,000 years, but its future suitability for this purpose is far from certain. Marine transgression and changes in agricultural practice have profound effects on this fragile environment, but the dynamics of cause and effect are not documented. A constructive policy for management and conservation of the machair must be based on an intimate knowledge of the environment, gained in detailed, multidisciplinary studies involving several years of close monitoring. The project described in this paper aims to define, in geomorphological and vegetational terms, the responses of the machair to changing patterns of agriculture, climatic conditions and rising sea levels.     

Multiple uses of liquepipets in Southern, northern, and western blots

Individually wrapped, sterile disposable transfer pipets can be used in the isolation of ds-DNA and ds-RNA fragments from gels as well as in the screening of multiple samples in Southern, Northern, and Western blots without potential contamination by exogenous nucleases and proteases. The sensitivity and results obtained by this method are comparable to those obtained by conventional methods. All the prehybridization, blocking, hybridization, and detection processes can be performed within the transfer pipet. The isotopically labeled probes used in hybridization can easily be recovered, stored for reuse, or disposed of as waste with no potential contamination of personnel or laboratory equipment. Strip blots are stable in appropriate buffers within the liquepipets which can be shipped easily worldwide for comparative analyses by collaborative investigators. This method is simple, time saving, and inexpensive and is particularly suitable for multiple sample screening. Other potential applications of this procedure are discussed.     

Toxicity, repellency, and effects of acetamiprid on western subterranean termite (Isoptera: Rhinotermitidae)

The insecticidial and biological activity of the cyano-substituted neonicotinoid acetamiprid was determined against the western subterranean termite, Reticulitermes hesperus Banks (Isoptera: Rhinotermitidae). Acetamiprid was very active against termites in topical applications, with an LD50 = 0.02 ng per termite. Even though acetamiprid was extremely toxic in topical applications, deposits > or =50 ppm on sand were required to consistently provide >90% kill of termites within 7 d after a 1-h exposure. Termites were quickly affected by brief exposures to sand treated with 1 ppm acetamiprid and within 1 h, their locomotion was dramatically impaired. Acetamiprid was transferred from donors to recipients only when donors were held on deposits > or =50 ppm for 1 h. Deposits even as low as 1 ppm were repellent and termites failed to tunnel into treated sand, and there was no significant mortality. Exposure to acetamiprid impaired locomotion of termites as did other slow-acting neonicotinoids, such as imidacloprid. Acetamiprid was repellent at all concentrations tested, acting like type I pyrethroid treatments in soil. A new subcategory of type III soil termiticides is proposed that incorporates the sublethal and delayed effects observed in neonicotinoid insecticides, and repellency at certain concentrations.     

A low-diversity,silicified Hirnantia Fauna from Butuo,southwestern Sichuan,on the western margin of Yangtze Platform

The latest Ordovician Hirnantia Fauna is distributed worldwide including South China, but with very few records from the western margin of the Yangtze Platform. A silicified Hirnantia Fauna from the uppermost Tiezufeike Formation in the Laoga section, Butuo County, southwestern Sichuan, enriches the fauna’s record and warrants the recognition of the upper part of the Tiezufeike Formation as the Kuanyinchiao Bed. Etching bulk limestone samples from this level with acetic acid yielded 275 specimens of Dalmanella testudinaria, Plectothyrella crassicosta, and Hindella crassa. The population dynamics are analyzed for three successive populations in the section. Size-frequency histograms and survivorship curves indicate gradual improvement of the palaeoenvironments during the end of the Late Ordovician glaciation. The low-diversity brachiopod assemblages recognized in our study are assigned to the Dalmanella-Plectothyrella Community (DP Community) according to their dominant species. It is comparable with two other examples of DP communities, one from the neighboring Guizhou Province of Southwest China, and the other from the Baltica Region.