scholarly journals Summer activity patterns for a moss and lichen in the maritime Antarctic with respect to altitude

Polar Biology ◽  
2021 ◽  
Author(s):  
Burkhard Schroeter ◽  
T. G. Allan Green ◽  
Ana Pintado ◽  
Roman Türk ◽  
Leopoldo G. Sancho
Keyword(s):  
Water Relations ◽  
Negative Impact ◽  
Activity Patterns ◽  
Vascular Plant ◽  
Water Source ◽  
Lapse Rate ◽  
Activity Duration ◽  
Main Driver ◽  
Biodiversity Change ◽  
Terrestrial Biodiversity

AbstractThere is considerable scientific interest as to how terrestrial biodiversity in Antarctica might respond, or be expected to respond, to climate change. The two species of vascular plant confined to the Antarctic Peninsula have shown clear gains in density and range extension. However, little information exists for the dominant components of the flora, lichens and bryophytes. One approach has been to look at change in biodiversity using altitude as a proxy for temperature change and previous results for Livingston Island suggested that temperature was the controlling factor. We have extended this study at the same site by using chlorophyll fluorometers to monitor activity and microclimate of the lichen, Usnea aurantiaco-atra, and the moss, Hymenoloma crispulum. We confirmed the same lapse rate in temperature but show that changes in water relations with altitude is probably the main driver. There were differences in water source with U. aurantiaco-atra benefitting from water droplet harvesting and the species performed substantially better at the summit. In contrast, activity duration, chlorophyll fluorescence and photosynthetic modelling all show desiccation to have a large negative impact on the species at the lowest site. We conclude that water relations are the main drivers of biodiversity change along the altitudinal gradient with nutrients, not measured here, as another possible contributor.

scholarly journals Effect of exotic tree plantation on floristic composition and phytodiversity of Rema-Kalenga wildlife sanctuary, Bangladesh

2016 ◽  
Vol 3 (2) ◽  
pp. 33-47
Author(s):  
Gazi Mosharof Hossain ◽  
ABM Enayet Hossain
Keyword(s):  
Plant Species ◽  
Negative Impact ◽  
Diversity Index ◽  
Vascular Plant ◽  
Floristic Composition ◽  
Natural Forest ◽  
Wildlife Sanctuary ◽  
Tree Plantation ◽  
Exotic Tree ◽  
Index Value

Effect of exotic tree plantation on floristic composition and phytodiversity status of Rema-Kalenga wildlife sanctuary of Bangladesh was studied. A total of 309 vascular plant species under 245 genera belonging to 83 families were found to constitute the vascular flora of the studied area. The maximum number of species (298) with the highest Shannon-Weiner diversity index value (3.882±0.090) was recorded from natural forest, which was followed by 194 and 165 plant species with 3.441±0.205 and 3.398±0.103 diversity index values recorded from Tectona and Acacia plantation sites respectively. The minimum number of plant species (142) with the lowest diversity index value (2.999±0.152) was recorded from Eucalyptus plantation site. The collected data on the selected forest sites of Rema-Kalenga wildlife sanctuary showed the trends of gradual decrease in floristic composition and phytodivesity status of three plantation sites (Tectona to Acacia to Eucalyptus) in respect to natural forest, which indicated that exotic tree plantations might have negative impact on floristic composition and phytodiversity of this semi-tropical forest area and the fast-growing exotic tree plantation of Acacia and Eucalyptus should be avoided for sustainable development of Rema-Kalenga wildlife sanctuary.Jahangirnagar University J. Biol. Sci. 3(2): 33-47, 2014 (December)

scholarly journals The COVID-19 Shock and Consumer Credit: Evidence from Credit Card Data

2021 ◽  
Vol 2021 (008) ◽  
pp. 1-55
Author(s):  
Akos Horvath ◽  
◽  
Benjamin Kay ◽  
Carlo Wix ◽  
◽  
...  
Keyword(s):  
Interest Rates ◽  
Credit Card ◽  
Negative Impact ◽  
Consumer Credit ◽  
Credit Cards ◽  
Sharp Decrease ◽  
Main Driver ◽  
Credit Card Data ◽  
Pandemic Severity ◽  
The Impact

We use credit card data from the Federal Reserve Board's FR Y-14M reports to study the impact of the COVID-19 shock on the use and availability of consumer credit across borrower types from March through August 2020. We document an initial sharp decrease in credit card transactions and outstanding balances in March and April. While spending starts to recover by May, especially for risky borrowers, balances remain depressed overall. We find a strong negative impact of local pandemic severity on credit use, which becomes smaller over time, consistent with pandemic fatigue. Restrictive public health interventions also negatively affect credit use, but the pandemic itself is the main driver. We further document a large reduction in credit card originations, especially to risky borrowers. Consistent with a tightening of credit supply and a flight-to-safety response of banks, we find an increase in interest rates of newly issued credit cards to less creditworthy borrowers.

Profit change and its drivers in the English and Welsh water industry: is output quality important?

Water Policy ◽  
2014 ◽  
Vol 20 (5) ◽  
pp. 995-1012 ◽  
Author(s):  
Alexandros Maziotis ◽  
David S. Saal ◽  
Emmanuel Thanassoulis ◽  
María Molinos-Senante
Keyword(s):  
Negative Impact ◽  
Scale Effects ◽  
Price Effect ◽  
Output Effect ◽  
Future Performance ◽  
Output Quality ◽  
Main Driver ◽  
Significant Negative Impact ◽  
Water Companies ◽  
Quantity Effect

Abstract The assessment of profit change over time and its drivers is essential to analyse firms' financial performance. This paper investigates profit change and its components for the 10 English and Welsh water and sewerage water companies over the period 1991–2008 and for three regulatory sub-periods. Profit changes and their drivers are computed following two approaches, namely: without controlling for water and sewerage quality issues, and after decomposing the output effect into high quality and low quality output effect. In both cases, profit change is decomposed into various factors such as quantity and price effect, technical change, efficiency change, resource mix, product mix, and scale effect. Profit change over the whole period was negative, with the substantial negative price effect being the main driver, which outstripped the positive quantity effect. This negative profit change was significantly marked from 2000 to 2005 while in the sub-period 1994–2000, which covers the 1994 price review, the profit change was positive. A further decomposition illustrated the significant negative impact of the input price and scale effects on profit changes. The methodology and conclusions of this paper are of great interest for both regulators and water utilities managers to improve future performance.

Xylem as the main origin of stem radius changes in Eucalyptus

2014 ◽  
Vol 41 (5) ◽  
pp. 520 ◽  
Author(s):  
Roman Zweifel ◽  
David M. Drew ◽  
Fritz Schweingruber ◽  
Geoffrey M. Downes
Keyword(s):  
Water Relations ◽  
Water Storage ◽  
Passive Layer ◽  
Specific Flow ◽  
Transport Efficiency ◽  
Art Interpretation ◽  
Main Driver ◽  
Additional Water ◽  
Species Specific ◽  
Slow Growing

The state-of-the-art interpretation of stem radius changes (DRTotal) for tree water relations is based on knowledge from mostly slow growing tree species. The ratio between diurnal size fluctuations of the rigid xylem (DRXylem) and the respective fluctuations of the elastic bark (DRBark) is known to be small (<0.4) and is of importance for the localisation of water storage dynamics in stems. In this study, fast growing Eucalyptus globulus Labill. in Tasmania were investigated by point dendrometers in order to investigate tree water relations. Unexpectedly, DRXylem was found to be the main driver of DRTotal with the bark acting as a passive layer on top of the fluctuating xylem under most conditions. Accordingly, the ratio between the diurnal fluctuations of the two tissues was found to be much higher (0.6–1.6) than everything reported before. Based on simulations using a hydraulic plant model, the high tissue-specific elasticity of the Eucalyptus xylem was found to explain this atypical response and not osmotically-driven processes or species-specific flow resistances. The wide zone of secondary thickening xylem in various stages of lignification is proposed to be an important component of the high wood elasticity. The tissue acts as additional water storage like the bark and may positively affect the water transport efficiency.

Assesment of Water Pollution in the Tigris River in Diyarbakır, Turkey

2010 ◽  
Vol 5 (1) ◽  
Author(s):  
Memet Varol ◽  
Bülent Gökot ◽  
Aysel Bekleyen
Keyword(s):  
Water Quality ◽  
River Water ◽  
Negative Impact ◽  
Oxygen Demand ◽  
Animal Husbandry ◽  
Water Source ◽  
Organic Pollution ◽  
Point Sources ◽  
Aquatic Life ◽  
Tigris River

Diyarbakır is the biggest city and the largest urban settlement in the Tigris Basin in Turkey. It has been gradually developing and growing thanks to the Southeastern Anatolia Project (GAP), and is one of the most important centers of industry, agriculture and animal husbandry in the Tigris Basin. The Tigris River is an important water source for the city, and it serves for irrigation, fishing, recreation and receiving wastewater. With the development of industry, agriculture and the growth of urban population, its pollution has become a serious problem. Pollution from domestic, industrial and agricultural activities has led to deterioration of water quality. In this context, the aim of the present study is to identify point sources of pollution and to assess the surface water quality of the Tigris River in the study area by monitoring physicochemical parameters. Diyarbakır produced a negative impact on the Tigris River water quality, particularly after the WWTP discharge. Concentrations of chemical oxygen demand, organic nitrogen, total nitrogen and total phosphorus increased markedly downstream of Diyarbakır WWTP discharge point. During the summer, the extent of organic pollution was so serious in the stations, downstream of WWTP, that dissolved oxygen became almost absent from the river water. The metal concentrations of all water samples were mostly below or close to the maximum permitted concentration for protection of aquatic life and drinking water.

scholarly journals Stable water isotope variation in a Central Andean watershed dominated by glacier- and snowmelt

2012 ◽  
Vol 9 (10) ◽  
pp. 12227-12269 ◽  
Author(s):  
N. Ohlanders ◽  
M. Rodriguez ◽  
J. McPhee
Keyword(s):  
Isotopic Composition ◽  
Negative Impact ◽  
Isotope Composition ◽  
Seasonal Pattern ◽  
Water Source ◽  
Close Relation ◽  
Related Factors ◽  
Central Chile ◽  
Glacier Melt ◽  
Glacial Cover

Abstract. Central Chile is an economically important region for which water supply is dependent on snow- and ice melt. Nevertheless, the fraction of water supplied by each of those two sources remains largely unknown. This study represents the first attempt to estimate the region's water balance using stable isotopes of water in streamflow and its sources; isotopic ratios of both H and O were monitored during one year in a high-altitude basin with a relatively high glacial cover (11.5%). We found that the steep altitude gradient of the studied catchment caused a corresponding gradient in snowpack isotopic composition and that this spatial variation had a profound effect on the temporal evolution of streamflow isotopic composition during snowmelt. Glacier- and snowmelt contributions to streamflow in the studied basin were calculated using a quantitative analysis of the isotopic composition of streamflow and its sources, resulting in a glacier melt contribution of 50–80% for the unusually dry melt year of 2011/12. This suggests that in (la Niña) years with little precipitation, glacier melt is an important water source for Central Chile. Predicted decreases in glacier melt due to global warming may therefore have a negative impact on water availability in the Central Andes as well as in comparable semi-arid regions of the world; this impact is non-commensurable with areal glacial cover or with the relative areal influence coverage of glacier versus seasonal snowpack. The pronounced seasonal pattern in streamflow isotope composition and its close relation to the evolution of snow cover and to discharge presents a potentially powerful tool for relating discharge evolution in mountainous, melt-dominated catchments with related factors such as contributions of sources to streamflow and snowmelt transit times.

scholarly journals Impacts of past abrupt land change on local biodiversity globally

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Martin Jung ◽  
Pedram Rowhani ◽  
Jörn P. W. Scharlemann
Keyword(s):  
Present Species ◽  
Land Change ◽  
Lag Effects ◽  
Biodiversity Change ◽  
Key Driver ◽  
Species Richness And Abundance ◽  
Taxonomic Groups ◽  
Terrestrial Biodiversity ◽  
Incomplete Assessments ◽  
Land Changes

AbstractAbrupt land change, such as deforestation or agricultural intensification, is a key driver of biodiversity change. Following abrupt land change, local biodiversity often continues to be influenced through biotic lag effects. However, current understanding of how terrestrial biodiversity is impacted by past abrupt land changes is incomplete. Here we show that abrupt land change in the past continues to influence present species assemblages globally. We combine geographically and taxonomically broad data on local biodiversity with quantitative estimates of abrupt land change detected within time series of satellite imagery from 1982 to 2015. Species richness and abundance were 4.2% and 2% lower, respectively, and assemblage composition was altered at sites with an abrupt land change compared to unchanged sites, although impacts differed among taxonomic groups. Biodiversity recovered to levels comparable to unchanged sites after >10 years. Ignoring delayed impacts of abrupt land changes likely results in incomplete assessments of biodiversity change.

scholarly journals Influence of season and weather on activity patterns of the numbat (Myrmecobius fasciatus) in captivity

2004 ◽  
Vol 52 (5) ◽  
pp. 475 ◽  
Author(s):  
C. E. Cooper ◽  
P. C. Withers
Keyword(s):  
Food Availability ◽  
Activity Patterns ◽  
Thermoregulatory Response ◽  
Low Light ◽  
Activity Data ◽  
Ambient Temperatures ◽  
Activity Duration ◽  
Study Activity ◽  
In Captivity ◽  
Low Levels

To separate the influence of weather from predation pressure and food availability, and to aid in the interpretation of activity data for wild numbats, we examined the influence of season and weather on the activity of captive numbats. Unlike other Australian marsupials, numbats are exclusively diurnal, being active for an average of 21.2% of the 24 h day. However, in the present study, activity duration varied seasonally, with numbats being active for longer periods in summer (39–65% of the available daylight) than winter (17–59%). During winter, captive numbats were active for shorter periods than wild numbats (presumably because captive numbats don't have to forage for food); however, they did not cease activity in the middle of the day during summer (suggesting that the inactivity of wild numbats at midday during summer is a response to food availability rather than a thermoregulatory response). Captive numbats were more active in summer than in winter, which may reflect their summer breeding season. Environmental conditions significantly affected daily activity, with low levels of activity recorded on days of low light intensity and high relative humidity. The majority of numbat activity occurred at ambient temperatures below thermoneutrality (<30°C). The associated costs of thermoregulation for active numbats were calculated, from activity time, to be higher in winter (0.586 mL O2 g–1 h–1) than in summer (0.274 mL O2�g–1�h–1).

scholarly journals Impact of Flag Texture on Tick Sampling Efficiency

2019 ◽  
Author(s):  
Philippe Gil De Mendonça
Keyword(s):  
Computer Modelling ◽  
Negative Impact ◽  
Animal Health ◽  
Activity Patterns ◽  
Epidemiological Studies ◽  
Tick Population ◽  
Sampling Efficiency ◽  
Field Sampling ◽  
Classical Statistics ◽  
The Impact

Background: There is a strong interest in tick-borne diseases worldwide due to their negative impact on both human and animal health. Epidemiological studies of tick-borne diseases depend on reliable data on tick population dynamics and activity patterns. Such data are essentially based on tick sampling in the field. This study aimed to evaluate the impact of cloth type on the efficiency of field sampling by the flagging technique. Methods: The impact of cloth type on the efficiency of field sampling by the flagging technique was investigated by comparing tick sampling yields of two different fabrics, the Munich type (MUC) vs. the Oxford type (OX), based on 30 pairs of transect lines. Data analysis included classical statistics and computer modelling. Results: The MUC flag yielded nearly five times more larval ticks than the OX flag, whereas the differences in yields for nymphs and adult ticks were not statistically significant based on classical statistics. Conclusion: The flag made of MUC type fabric, thanks to its tight and relatively flat texture, facilitates detection and collection of ticks from its surface. The OX flag, due to its loose texture, is unsuitable for the quantitative sampling of larval Ixodes ricinus.

scholarly journals Feeding Cannabidiol (CBD)-Containing Treats Did Not Affect Canine Daily Voluntary Activity

2021 ◽  
Vol 8 ◽  
Author(s):  
Elizabeth M. Morris ◽  
Susanna E. Kitts-Morgan ◽  
Dawn M. Spangler ◽  
Jessica Gebert ◽  
Eric S. Vanzant ◽  
...  
Keyword(s):  
Daily Activity ◽  
Block Design ◽  
Activity Patterns ◽  
Companion Animals ◽  
Time Of Day ◽  
Activity Level ◽  
Quiet Time ◽  
Voluntary Activity ◽  
Activity Data ◽  
Activity Duration

Growing public interest in the use of cannabidiol (CBD) for companion animals has amplified the need to elucidate potential impacts. The purpose of this investigation was to determine the influence of CBD on the daily activity of adult dogs. Twenty-four dogs (18.0 ± 3.4 kg, 9 months−4 years old) of various mixed breeds were utilized in a randomized complete block design with treatments targeted at 0 and 2.5 mg (LOW) and at 5.0 mg (HIGH) CBD/kg body weight (BW) per day split between two treats administered after twice-daily exercise (0700–0900 and 1,700–1,900 h). Four hours each day [1,000–1,200 h (a.m.) and 1,330–1,530 h (p.m.)] were designated as times when no people entered the kennels, with 2 h designated as Quiet time and the other 2 h as Music time, when calming music played over speakers. Quiet and Music sessions were randomly allotted to daily a.m. or p.m. times. Activity monitors were fitted to dogs' collars for continuous collection of activity data. Data were collected over a 14-day baseline period to establish the activity patterns and block dogs by activity level (high or low) before randomly assigning dogs within each block to treatments. After 7 days of treatment acclimation, activity data were collected for 14 days. Data were examined for differences using the MIXED procedure in SAS including effects of treatment, day, session (Quiet or Music), time of day (a.m. or p.m.), and accompanying interactions. CBD (LOW and HIGH) did not alter the total daily activity points (P = 0.985) or activity duration (P = 0.882). CBD tended (P = 0.071) to reduce total daily scratching compared with the control. Dogs were more active in p.m. sessions than in a.m. sessions (P &lt; 0.001). During the p.m. session, dogs receiving HIGH tended (P = 0.091) to be less active than the control (CON). During the a.m. and p.m. sessions, CBD reduced scratching compared with CON (P = 0.030). CBD did not affect the activity duration during exercise periods (P = 0.143). These results indicate that, when supplemented with up to 4.5 mg CBD/kg BW/day, CBD does not impact the daily activity of adult dogs, but may exert an antipruritic effect.

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