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1.
To understand thermal preferences and to define a preliminary outdoor comfort range for the local population of Glasgow, UK, an extensive series of measurements and surveys was carried out during 19 monitoring campaigns from winter through summer 2011 at six different monitoring points in pedestrian areas of downtown Glasgow. For data collection, a Davis Vantage Pro2 weather station equipped with temperature and humidity sensors, cup anemometer with wind vane, silicon pyranometer and globe thermometer was employed. Predictions of the outdoor thermal index PET (physiologically equivalent temperature) correlated closely to the actual thermal votes of respondents. Using concurrent measurements from a second Davis Vantage Pro2 weather station placed in a rural setting approximately 15 km from the urban area, comparisons were drawn with regard to daytime thermal comfort levels and urban–rural temperature differences (?Tu-r) for the various sites. The urban sites exhibited a consistent lower level of thermal discomfort during daytime. No discernible effect of urban form attributes in terms of the sky-view factor were observed on ?Tu-r or on the relative difference of the adjusted predicted percentage of dissatisfied (PPD*). 相似文献
2.
Dimitris K. Papanastasiou Dimitris Melas Thomas Bartzanas Constantinos Kittas 《International journal of biometeorology》2010,54(3):307-317
During the summer of 2007 several Greek regions suffered periods of extreme heat, with midday temperatures of over 40°C on
several consecutive days. High temperatures were also recorded on the east coast of central Greece, where a complex sea breeze
circulation system frequently develops. The more intense events occurred at the end of June and July. The highest temperatures
were observed on 26 June and 25 July, while the sea breeze developed only on 25 July. Meteorological data collected at two
sites—a coastal urban location and an inland suburban site that is not reached by the sea breeze flow—as well as pollution
data collected at the urban site, were analysed in order to investigate the relationship between sea breeze development and
the prevailing environmental conditions during these two heat wave events. The analysis revealed that sea breeze development
affects temperature and pollution levels at the shoreline significantly, causing a decrease of ~4°C from the maximum temperature
value and an increase of ~30% in peak PM10 levels. Additionally, several stress indices were calculated in order to assess
heat comfort conditions at the two sites. It was found that nocturnal comfort levels are determined mainly by the urban heat
island effect, the intensity of which reaches up to 8°C, while the applied indices do not demonstrate any significant daytime
thermal stress relief due to sea breeze development. 相似文献
3.
The goal of the present study was to investigate the influence of urbanization on the richness, abundance and composition of arthropod communities associated with creosote bush, Larrea tridentata [DC] Cov., in Phoenix, Arizona. Arthropod communities were sampled in two desert types varying in degree of urbanization including fringe deserts (relatively undisturbed expanses of desert outside of Phoenix) and urban deserts (patches of desert within the urban core of Phoenix). Two studies were conducted including (1) a seasonal study (conducted at two fringe desert and two urban desert sites over a nine-month period), and (2) a snapshot study (conducted at multiple fringe desert and urban desert sites over an eight-day period). Results from both studies demonstrated that overall richness and abundance of creosote bush arthropod communities were lower in urban deserts than in fringe deserts. Additionally, creosote bush arthropod community composition varied greatly, both temporally and spatially. These differences in richness and abundance between fringe deserts and urban deserts suggest that the creosote bush arthropod community may be a useful focal biotic community to monitor when assaying for environmental change due to urbanization in arid habitats. 相似文献
4.
Seasonal Biotransformation of Naphthalene, Phenanthrene, and Benzo[a]pyrene in Surficial Estuarine Sediments 总被引:7,自引:6,他引:1
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Michael P. Shiaris 《Applied microbiology》1989,55(6):1391-1399
Transformation rates of naphthalene, phenanthrene, and benzo[a]pyrene in oxidized surficial sediments of a polluted urban estuary, Boston Harbor, Mass., were determined over a period of 15 months. Three sites characterized by muddy sediments were selected to represent a >300-fold range of ambient polycyclic aromatic hydrocarbon (PAH) concentration. Transformation rates were determined by a trace-level radiolabel PAH assay which accounted for PAH mineralization, the formation of polar metabolites, residue, and recovered parental PAHs in sediment slurries. Transformation rates of the model PAHs increased with increasing ambient PAH concentrations. However, turnover times for a given PAH were similar at all sites. The turnover times were as follows: naphthalene, 13.2 to 20.1 days; phenanthrene, 7.9 to 19.8 days, and benzo[a]pyrene, 53.7 to 82.3 days. At specific sites, rates were significantly affected by salinity, occasionally affected by temperature, but not affected by pH over the course of the study. Seasonal patterns of mineralization were observed for each of the PAHs at all sites. The timing of seasonal maxima of PAH mineralization varied from site to site. Seasonal potential heterotrophic activities as measured by acetate and glutamate mineralization rates did not always coincide with PAH mineralization maxima and minima, suggesting that the two processes are uncoupled in estuarine sediments. 相似文献
5.
Aims To assess the role of moisture in phenological timing in the mediterranean coastal flora of Baja California, and specifically to assess the role of coastal fog and ocean-derived moisture in plant phenology. Moisture seems to be the primary driver of flowering times and durations at the arid end of the mediterranean-climate region, where rainfall is often sporadic (temperature and day length can be expected to play a much lesser role as they are not growth limiting). We aimed to understand: What factors drive climatic variation between sites? Are there general flowering patterns allowing us to identify phenological categories? Do flowering patterns vary in relation to site-specific weather? and most importantly, does maritime influence on weather affect flowering dynamics in coastal mediterranean ecosystems?Methods The southernmost extent of the California Floristic Province (in Baja California, Mexico) is a biological diversity hotspot of high endemism and conservation value, with two steep moisture gradients: rainfall (N–S) and coastal fogs (W–E), providing an ideal study system. We installed five weather stations across the moisture gradients, recording data hourly. We monitored flowering phenology in the square kilometer surrounding each weather station from 2010 to 2013. About 86 plant taxa were monitored across the five sites, every 6–8 weeks. Averaged climatic data is presented with general trends in flowering, and specific flowering syndromes were observed. Data for flowering intensity across the sites was analyzed using a principal components analysis.Important findings Data analysis demonstrates a general seasonal pattern in flowering times, but distinct differences in local weather and phenology between the five study sites. Three flowering syndromes are revealed in the flora: (i) water responders or spring bloomers, (ii) day-length responders or fall-blooming taxa and (iii) aseasonal bloomers with no seasonal affinity. The two moisture gradients are the strongest drivers of flowering times. Inland sites showed higher phenological variation than coastal sites where seasonality is dampened by ocean-derived moisture, which extends and buffers perennial plant phenology and is a probable driver of local endemism. Phenological controls vary globally with climate and geography; moisture is the primary driver of phenology in mediterranean climates and fog is an important climatic variable in coastal Mexico. 相似文献
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Yusuke Fukuda Craig Moritz Nancy N. FitzSimmons Namchul Jang Grahame Webb Garry Lindner Hamish Campbell Keith Christian Steven Leeder Sam Banks 《The Journal of wildlife management》2024,88(2):e22525
Management programs that successfully recovered wild saltwater crocodile (Crocodylus porosus) populations in the Northern Territory of Australia did so with an expanding commitment to maintaining public safety. One aspect of the program is the ongoing removal of resident and immigrant crocodiles within Darwin Harbor (since 1979), the main urban center. We determined the likely sources of crocodiles caught as problem animals between 2015–2017 by comparing recently developed methods for population assignment. Depending on the assignment model used, we estimated that between 30% and 50% of crocodiles in Darwin Harbor originated from the Adelaide and Mary rivers, and the Kakadu region east of Darwin, and between 20% and 30% of crocodiles originated from the Finniss, Reynolds, and Daly rivers southwest of Darwin. Saltwater crocodiles occur at particularly high densities in these catchments. The remainder came from a mixture of different sources across the Northern Territory. The most common animals captured were immature (150–180 cm) males that have traveled 100–200 km. We did not identify any relationships between the distance from the inferred origin to Darwin Harbor and the size and sex of the crocodiles, or the year of capture. The targeted removal of crocodiles from specific sites such as Darwin Harbor, near where most people live, improves public safety in the highest risk areas, without compromising abundant source populations in most areas. 相似文献
9.
Agnieszka Grinn-Gofroń Agnieszka Strzelczak 《International journal of biometeorology》2011,55(2):235-241
Ganoderma sp. is an airborne fungal spore type known to trigger respiratory allergy symptoms in sensitive patients. Aiming to reduce
the risk for allergic individuals, we analysed fungal spore circulation in Szczecin, Poland, and its dependence on meteorological
conditions. Statistical models for the airborne spore concentrations of Ganoderma sp.—one of the most abundant fungal taxa in the area—were developed. Aerobiological sampling was conducted over 2004–2008
using a volumetric Lanzoni trap. Simultaneously, the following meteorological parameters were recorded: daily level of precipitation,
maximum and average wind speed, relative humidity and maximum, minimum, average and dew point temperatures. These data were
used as the explaining variables. Due to the non-linearity and non-normality of the data set, the applied modelling techniques
were artificial neural networks (ANN) and mutlivariate regression trees (MRT). The obtained classification and MRT models
predicted threshold conditions above which Ganoderma sp. appeared in the air. It turned out that dew point temperature was the main factor influencing the presence or absence
of Ganoderma sp. spores. Further analysis of spore seasons revealed that the airborne fungal spore concentration depended only slightly
on meteorological factors. 相似文献
10.
Lettner H Hubmer A Bossew P Strebl F Steinhäusler F 《Radiation and environmental biophysics》2009,48(1):47-56
In the mountainous “Hohe Tauern” region of Salzburg (Austria), milk samples have been collected in a long-term montitoring
programme since 1988, at eight alpine sites used for extensive, seasonal stock farming. For this alpine environment with its
acidic soils developed on silicate bedrock, high soil-to-plant transfer factors and long-lasting 137Cs contamination levels in milk—the main product of seasonal agriculture at elevated altitudes—are characteristic features.
The decrease in 137Cs concentration in milk measured since 1988 turned out to be best described by one or two effective half-lives. For the period
from 1993 to 2007, which can be modelled with one effective half-life for all sites, effective half-lives between 3.7 and
15.0 years (ecological half-lives: 4.3–29.9 years) were obtained. The effective half-life increases with mean altitude of
the investigated graze pastures, probably due to reduced migration velocities of 137Cs and low 137Cs half-value depths of a few centimetres in the soil. 相似文献
11.
Christian Nellemann Ingunn Vistnes Per Jordhøy Ole‐Gunnar Støen Bjørn Petter Kaltenborn Frank Hanssen Rannveig Helgesen 《Restoration Ecology》2010,18(6):873-881
Conservation efforts have secured the partial recovery of Europe's wild reindeer, although only in 24 separate fragments of their original range, now separated by resorts and roads. Full recovery of the original range will require restoration of migration routes across developed or disturbed areas. We analyzed distribution of around 3500 Rangifer tarandus tarandus (reindeer) during winters (1984–2005) in relation to 10 alpine resorts and prior to and following relocation of ski trails and cabins in Norway done to restore use of former habitat. Reindeer used areas within 15 km of resorts, which is less than expected based on the availability of habitat, most likely as a result of cross‐country skiing activity surrounding the resorts, limiting their access to other ranges and historic migration corridors. Reindeer abundance declined and mean distance between reindeer groups and resorts increased with increasing resort size. No apparent habituation to resorts was observed during the 20‐year study period. However, when ski trails and an associated tourist cabin were removed to restore access to historic habitat, reindeer moved into the area. No such change in reindeer distribution was observed in the 10 years preceding relocation, or at the other nine resorts where no such experiments were conducted. Regulation of human traffic, relocation of trails, and removal of infrastructure and cabins are apparently effective in restoring access to and use of historic ranges and migration routes. However, restoration of historic migration routes between ranges will likely require the removal of hundreds of recreational cabins in order to become effective. 相似文献
12.
Studies on the thermal comfort of humans in urban areas require meteorological data such as air temperature, air humidity,
wind speed, and short- and long-wave fluxes. In such studies radiation fluxes can be expressed by the mean radiant temperature—a
parameter with high variability in urban areas due to variability in global radiation. Wind speed in urban areas is influenced
by urban obstacles and their orientation. Both mean radiant temperature and wind speed can be modified or changed by different
height-to-width ratios or orientation of urban structures. Modifications to these parameters by typical urban structures (represented
by the height-to-width ratio) can result in variation of mean radiant temperature over a range of more than 30°C, which can
correspond to three levels of thermal stress. The results presented here provide a possible means of comparing different urban
configurations in different climate regions. 相似文献
13.
Wendy Servoss Richard M. Engeman Steven Fairaizl John L. Cummings N. Paige Groninger 《International biodeterioration & biodegradation》2000,45(3-4)
We examined wildlife abundance, distribution, and movement patterns at Phoenix Sky Harbor International Airport (PHX) and within an 8-km radius to assess current air-strike hazards, and to provide baseline information for projecting changes in air-strike hazards as land-use patterns around PHX change. We found that water sources at or near PHX especially induced wildlife movement patterns that put air traffic at risk. This was particularly true of the Salt River bed adjacent to the airport, which also is a natural flight corridor for birds. Compounding the problem, air traffic at PHX was the heaviest when bird abundance and activity was the greatest during migration and breeding. We feel that air strike hazards at PHX are likely to increase substantially as the Salt River bed is reclaimed to produce additional lakes and high quality riparian habitat. We offer recommendations to reduce the hazard levels currently found at PHX and to reduce additional hazards as the habitat around PHX is converted and produces more attractive wildlife habitat. 相似文献
14.
T. G. Sokolovskaya A. S. Sokolovsky I. V. Epur 《Russian Journal of Marine Biology》2010,36(2):125-132
We summarize the results of a study of the taxonomic composition and seasonal variations of ichthyoplankton in Vostok Bay.
Samples were collected during 2003–2008 at a stationary light station located on the mooring module of the experimental biological
station Vostok (Institute of Marine Biology). Within the observation period, larval and juvenile fish of 67 species belonging
to 11 orders and 30 families were found in 412 samples. The seasonal dynamics of species composition of ichthyoplankton were
examined over the period from March to November. The number of species in the samples changed from 40–36 in April–May, respectively,
to 6 species in October. The contribution of resident species and southern migrants to the ichthyoplankton samples was estimated.
The light station sampling has proven to be most effective in studying the species diversity of the ichthyofauna in Vostok
Bay. Using light station sampling, 18 fish species were found that were not recorded using other sampling techniques. 相似文献
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16.
The temporal availability of propagules is a critical factor in sustaining pioneer riparian tree populations along snowmelt-driven
rivers because seedling establishment is strongly linked to seasonal hydrology. River regulation in semi-arid regions threatens
to decouple seed development and dispersal from the discharge regime to which they evolved. Using the lower Tuolumne River
as a model system, we quantified and modeled propagule availability for Populus fremontii (POFR), Salix gooddingii (SAGO), and Salix exigua (SAEX), the tree and shrub species that dominate near-channel riparian stands in the San Joaquin Basin, CA. A degree-day
model was fit to field data of seasonal seed density and local temperature from three sites in 2002–2004 to predict the onset
of the peak dispersal period. To evaluate historical synchrony of seed dispersal and seasonal river hydrology, we compared
peak spring runoff timing to modeled peak seed release periods for the last 75 years. The peak seed release period began on
May 15 for POFR (range April 23–June 10), May 30 for SAGO (range May 19–June 11) and May 31 for SAEX (range May 8–June 30).
Degree-day models for the onset of seed release reduced prediction error by 40–67% over day-of-year means; the models predicted
best the interannual, versus site-to-site, variation in timing. The historical analysis suggests that POFR seed release coincided
with peak runoff in almost all years, whereas SAGO and SAEX dispersal occurred during the spring flood recession. The degree-day
modeling approach reduce uncertainty in dispersal timing and shows potential for guiding flow releases on regulated rivers
to increase riparian tree recruitment at the lowest water cost. 相似文献
17.
Convergence and contingency in production–precipitation relationships in North American and South African C4 grasslands 总被引:1,自引:0,他引:1
Mesic grasslands in North America and South Africa share many structural attributes, but less is known of their functional similarities. We assessed the control of a key ecosystem process, aboveground net primary production (ANPP), by interannual variation in precipitation amount and pattern via analysis of data sets (15- and 24-year periods) from long-term research programs on each continent. Both sites were dominated by C4 grasses and had similar growing season climates; thus, we expected convergence in precipitation–ANPP relationships. Lack of convergence, however, would support an alternative hypothesis—that differences in evolutionary history and purportedly greater climatic variability in South Africa fundamentally alter the functioning of southern versus northern hemisphere grasslands. Neither mean annual precipitation nor mean ANPP differed between the South African and North American sites (838 vs. 857 mm/year, 423.5 vs. 461.4 g/m2 respectively) and growing season precipitation–ANPP relationships were similar. Despite overall convergence, there were differences between sites in how the seasonal timing of precipitation affected ANPP. In particular, interannual variability in precipitation that fell during the first half of the growing season strongly affected annual ANPP in South Africa (P < 0.01), but was not related to ANPP in North America (P = 0.098). Both sites were affected similarly by late season precipitation. Divergence in the seasonal course of available soil moisture (chronically low in the winter and early spring in the South African site vs. high in the North American site) is proposed as a key contingent factor explaining differential sensitivity in ANPP to early season precipitation in these two grasslands. These long-term data sets provided no support for greater rainfall, temperature or ANPP variability in the South African versus the North American site. However, greater sensitivity of ANPP to early season precipitation in the South African grassland suggests that future patterns of productivity may be more responsive to seasonal changes in climate compared with the North American site. 相似文献
18.
Microbial eukaryotic community (0.8–20 μm) composition and its seasonal variation were investigated in large, shallow, subtropical
Lake Taihu located in Southeast China. The water samples were collected monthly from August 2006 to July 2007 at two sites
distantly located in Meiliang Bay and Lake Center, which differed strongly in their trophic status and sediment resuspension.
The microbial eukaryotic community compositions (MECC) were measured using denaturing gradient gel electrophoresis (DGGE)
of PCR-amplified eukaryotic 18S rRNA gene fragments. Seasonal variations were related to environmental factors by means of
redundancy analysis (RDA) in order to reveal the most important regulating factors. At both sites, the structures and Shannon–Wiener
indices of the microbial eukaryotic communities displayed apparent seasonal variations, which were significantly related to
environmental variables. There were significant intrahabitat differences in environmental factors regulating MECC, as well
as in the seasonal dynamics of the two sites during the study period. At Meiliang Bay, the variations of total phosphorus
concentration and cladocera abundance had the most profound impacts on the microbial eukaryotic community composition, while
at Lake Center, the total nitrogen concentration and conductivity were most influential. Our results suggest that the DGGE
method is a cost-effective way to analyze the seasonal dynamics of MECC and their interaction with environmental variables,
which will provide new insights into the diversity and dynamics of MECC. 相似文献
19.
Ovaries of four flatfish species—Liopsetta pinnifasciata, Pleuronectes obscurus, Pleuronectes yokohamae, and Glyptocephalus stelleri, as well as of Far Eastern navaga Eleginus gracilis and rudd Tribolodon brandtii caught in Peter the Great Bay of the Sea of Japan in prespawning and/or spawning periods were studied. Under conditions of
anthropogenic pollution of the bay, the state of fish ovaries is determined by several factors, such as migration activity,
mode of life (bottom or pelagic), and the degree of sites pollution where females stayed in the period of the vitellogenous
growth of oocytes. The pollution of the bay exerts the most damaging effect on the reproductive system of shallow species
of flatfish—L. pinnifasciata and P. obscurus—that do not perform far migrations and throughout their life stay in the zone exposed to toxicants. In navaga Eleginus gracilis and flatfish P. yokohamae, and G. stelleri that perform seasonal migrations, no damages of ovaries were found. 相似文献
20.
City spore concentrations in the European Economic Community (EEC). VI. Poaceae (Grasses), 1982–1986
Frits Th. M. Spieksma Gennaro D'amato John Mullins Nicole Nolard Reinhard Wachter Eva R. Weeke 《Aerobiologia》1989,5(1):38-43
Summary Airborne grass-pollen concentrations in six cities in the EEC are compared, based on observations from five years, 1982–1986.
Results show that there are quantitative differences both between the monitoring stations and between the years. Very provisionally,
the average seasonal total of the European urban airborne grass-pollen concentration can be put at 4 to 5000 per m3 of air. Also qualitatively, regarding the seasonal fluctuations, there are differences between the stations, and between
the years. Generally, the results confirm that June is the most typical grass-pollen month in northwestern Europe, whereas
in mediterranean Europe May is the more prominent grass-pollen period. There seems to be little coherence between the starting
dates of the grass-pollen season even at relatively nearby stations in northwestern Europe, suggestive for a great influence
of the actual weather situation. 相似文献