scholarly journals Some like it hot: A differential response to changing temperatures by the malaria vectors Anopheles funestus and An. gambiae s.l.

2016 ◽  
Author(s):  
Jacques D Charlwood
Keyword(s):  
Air Temperature ◽  
Light Trap ◽  
Anopheles Funestus ◽  
Malaria Vectors ◽  
Effect Of Temperature ◽  
Night Time ◽  
Environmental Correlations ◽  
Air Temperatures ◽  
Soil Temperatures ◽  
Gravid Females

Background: With the possible implications of global warming, the effect of temperature on the dynamics of malaria vectors in Africa has become a subject of increasing interest. Information from the field is, however, relatively sparse. We describe the effect of ambient temperature over a five-year period on the dynamics of An. funestus and An. gambiae s.l., collected from a single village in southern Mozambique where temperatures varied from a night-time minimum of 6oC in the cool season to a daytime maximum of 35oC in the hot season. Results: Mean daily air temperatures varied from 34o C to 20oC and soil temperatures varied from 26 o C to 12 o C. Diurnal variation was greatest in the cooler months of the year and were greater in air temperatures than soil temperatures. During the study 301, 705 female An. funestus were collected in 6043 light-trap collections, 161, 466 in 7397 exit collections and 16, 995 in 1315 resting collections. The equivalent numbers for An. gambiae s.l. are 72, 475 in light-traps, 33, 868 in exit collections and 5, 333 from indoor resting collections. Numbers of mosquito were greatest in the warmer months. Numbers of An. gambiae s.l. went through a one hundredfold change (from a mean of 0.14 mosquitoes a night to 14) whereas numbers of An. funestus merely doubled (from a mean of 20 to 40 a night). The highest environmental correlations and mosquito numbers were between mean air temperature (r2 = 0.52 for An. funestus and 0.77 for An. gambiae s.l.). Numbers of mosquito collected were not related to rainfall with lags of up to four weeks. Numbers of both gravid and unfed An. gambiae complex females in exit collections continued to increase at all temperatures recorded but gravid females of An. funestus decreased at temperatures above 28oC. Overall the numbers of gravid and unfed An. funestus collected in exit collections were not correlated (p = 0.07). For an unknown reason the number of An. gambiae s.l. fell below monitoring thresholds during the study. Conclusions: Mean air temperature was the most important environmental parameter affecting both vectors in this part of Mozambique. Numbers of An. gambiae s.l. increased at all temperatures recorded whilst An. funestus appeared to be adversely affected by temperatures of 28oC and above. These differences may influence the distribution of the vectors as the planet warms.

scholarly journals Some like it hot: A differential response to changing temperatures by the malaria vectors Anopheles funestus and An. gambiae s.l.

2016 ◽  
Author(s):  
Jacques D Charlwood
Keyword(s):  
Air Temperature ◽  
Light Trap ◽  
Anopheles Funestus ◽  
Malaria Vectors ◽  
Effect Of Temperature ◽  
Night Time ◽  
Environmental Correlations ◽  
Air Temperatures ◽  
Soil Temperatures ◽  
Gravid Females

Background: With the possible implications of global warming, the effect of temperature on the dynamics of malaria vectors in Africa has become a subject of increasing interest. Information from the field is, however, relatively sparse. We describe the effect of ambient temperature over a five-year period on the dynamics of An. funestus and An. gambiae s.l., collected from a single village in southern Mozambique where temperatures varied from a night-time minimum of 6oC in the cool season to a daytime maximum of 35oC in the hot season. Results: Mean daily air temperatures varied from 34o C to 20oC and soil temperatures varied from 26 o C to 12 o C. Diurnal variation was greatest in the cooler months of the year and were greater in air temperatures than soil temperatures. During the study 301, 705 female An. funestus were collected in 6043 light-trap collections, 161, 466 in 7397 exit collections and 16, 995 in 1315 resting collections. The equivalent numbers for An. gambiae s.l. are 72, 475 in light-traps, 33, 868 in exit collections and 5, 333 from indoor resting collections. Numbers of mosquito were greatest in the warmer months. Numbers of An. gambiae s.l. went through a one hundredfold change (from a mean of 0.14 mosquitoes a night to 14) whereas numbers of An. funestus merely doubled (from a mean of 20 to 40 a night). The highest environmental correlations and mosquito numbers were between mean air temperature (r2 = 0.52 for An. funestus and 0.77 for An. gambiae s.l.). Numbers of mosquito collected were not related to rainfall with lags of up to four weeks. Numbers of both gravid and unfed An. gambiae complex females in exit collections continued to increase at all temperatures recorded but gravid females of An. funestus decreased at temperatures above 28oC. Overall the numbers of gravid and unfed An. funestus collected in exit collections were not correlated (p = 0.07). For an unknown reason the number of An. gambiae s.l. fell below monitoring thresholds during the study. Conclusions: Mean air temperature was the most important environmental parameter affecting both vectors in this part of Mozambique. Numbers of An. gambiae s.l. increased at all temperatures recorded whilst An. funestus appeared to be adversely affected by temperatures of 28oC and above. These differences may influence the distribution of the vectors as the planet warms.

scholarly journals Some like it hot: a differential response to changing temperatures by the malaria vectorsAnopheles funestusandAn. gambiaes.l.

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3099 ◽  
Author(s):  
Jacques Derek Charlwood
Keyword(s):  
Air Temperature ◽  
Light Trap ◽  
Malaria Vectors ◽  
Effect Of Temperature ◽  
Night Time ◽  
Environmental Correlations ◽  
Air Temperatures ◽  
Unknown Reason ◽  
Soil Temperatures ◽  
Gravid Females

BackgroundWith the possible implications of global warming, the effect of temperature on the dynamics of malaria vectors in Africa has become a subject of increasing interest. Information from the field is, however, relatively sparse. We describe the effect of ambient temperature over a five-year period on the dynamics ofAn. funestusandAn. gambiaes.l., collected from a single village in southern Mozambique where temperatures varied from a night-time minimum of 6 °C in the cool season to a daytime maximum of 35 °C in the hot season.ResultsMean daily air temperatures varied from 34 °C to 20 °C and soil temperatures varied from 26 °C to 12 °C. Diurnal variation was greatest in the cooler months of the year and were greater in air temperatures than soil temperatures. During the study 301, 705 femaleAn. funestuswere collected in 6,043 light-trap collections, 161, 466 in 7,397 exit collections and 16, 995 in 1,315 resting collections. The equivalent numbers forAn. gambiaes.l. are 72,475 in light-traps, 33, 868 in exit collections and 5,333 from indoor resting collections. Numbers of mosquito were greatest in the warmer months. Numbers ofAn. gambiaes.l. went through a one hundredfold change (from a mean of 0.14 mosquitoes a night to 14) whereas numbers ofAn. funestusmerely doubled (from a mean of 20 to 40 a night). The highest environmental correlations and mosquito numbers were between mean air temperature (r2 = 0.52 forAn. funestusand 0.77 forAn. gambiaes.l.). Numbers of mosquito collected were not related to rainfall with lags of up to four weeks. Numbers of both gravid and unfedAn. gambiaecomplex females in exit collections continued to increase at all temperatures recorded but gravid females ofAn. funestusdecreased at temperatures above 28 °C. Overall the numbers of gravid and unfedAn. funestuscollected in exit collections were not correlated (p = 0.07). For an unknown reason the number ofAn. gambiaes.l. fell below monitoring thresholds during the study.ConclusionsMean air temperature was the most important environmental parameter affecting both vectors in this part of Mozambique. Numbers ofAn. gambiaes.l. increased at all temperatures recorded whilstAn. funestusappeared to be adversely affected by temperatures of 28 °C and above. These differences may influence the distribution of the vectors as the planet warms.

scholarly journals Seasonal dynamics of methane emissions from a subarctic fen in the Hudson Bay Lowlands

2013 ◽  
Vol 10 (7) ◽  
pp. 4465-4479 ◽  
Author(s):  
K. L. Hanis ◽  
M. Tenuta ◽  
B. D. Amiro ◽  
T. N. Papakyriakou
Keyword(s):  
Soil Temperature ◽  
Air Temperature ◽  
Growing Season ◽  
Near Surface ◽  
Growing Seasons ◽  
Air Temperatures ◽  
Soil Temperatures ◽  
Surface Soil Temperature ◽  
Filling Method ◽  
Highly Correlated

Abstract. Ecosystem-scale methane (CH4) flux (FCH4) over a subarctic fen at Churchill, Manitoba, Canada was measured to understand the magnitude of emissions during spring and fall shoulder seasons, and the growing season in relation to physical and biological conditions. FCH4 was measured using eddy covariance with a closed-path analyser in four years (2008–2011). Cumulative measured annual FCH4 (shoulder plus growing seasons) ranged from 3.0 to 9.6 g CH4 m−2 yr−1 among the four study years, with a mean of 6.5 to 7.1 g CH4 m−2 yr−1 depending upon gap-filling method. Soil temperatures to depths of 50 cm and air temperature were highly correlated with FCH4, with near-surface soil temperature at 5 cm most correlated across spring, fall, and the shoulder and growing seasons. The response of FCH4 to soil temperature at the 5 cm depth and air temperature was more than double in spring to that of fall. Emission episodes were generally not observed during spring thaw. Growing season emissions also depended upon soil and air temperatures but the water table also exerted influence, with FCH4 highest when water was 2–13 cm below and lowest when it was at or above the mean peat surface.

Soil and air temperatures during prescribed cerated fires in Central Brazil

1993 ◽  
Vol 9 (3) ◽  
pp. 313-320 ◽  
Author(s):  
Antonio Carlos Miranda ◽  
Heloisa Sinátora Miranda ◽  
Inês de Fátima Oliveira Dias ◽  
Braulio Ferreira de Souza Dias
Keyword(s):  
Air Temperature ◽  
Sensu Stricto ◽  
Temperature Measurements ◽  
Fuel Load ◽  
Native Vegetation ◽  
Central Brazil ◽  
Type K ◽  
Air Temperatures ◽  
Soil Temperatures ◽  
Recorded Data

ABSTRACTAir and soil temperatures were measured during dry season heading fires in three different physiognomic forms of native vegetation common in Central Brazil: cerrado sensu stricto (dense scrub of shrubs and trees), campo cerrado (open scrub), and campo sujo (open grassland with scattered shrubs). The vegetation was protected from fire for 15 y in some areas, had been burned once every two years, and once each year in other areas. The temperatures were measured with type-k thermocouples and recorded at intervals of 22.5 sees. Air temperature measurements were taken at 1, 60 and 160 cm. Maximum air temperatures ranged from 85°C to 840°C, and the duration above 60°C varied from 20 to 270 seconds. In the soil, negligible temperature increases were recorded below 5 cm depth, whereas at 2 cm maximum soil temperatures varied from 29 to 38°C. Possible influences of fuel load and moisture on the recorded data and on the behaviour of fire in the cerrado ecosystems are discussed.

A Study of the Annual Soil Temperature Wave

1952 ◽  
Vol 5 (2) ◽  
pp. 303 ◽  
Author(s):  
ES West
Keyword(s):  
Soil Temperature ◽  
Air Temperature ◽  
Temperature Wave ◽  
Theoretical Equation ◽  
Mean Temperature ◽  
Air Temperatures ◽  
Soil Temperatures

Soil temperatures recorded at Griffith over an 8 year period at a depth ranging from 1 in. to 8 ft. have been examined and compared with air temperatures. The observed fluctuations m the soil temperatures fit closely the theoretical equation for the propagation of a simple harmonic temperature wave into the so11. The diffusivity of the sol1 has been deduced and compared with values found by other workers in other localities. The annual wave of the daily mean temperature at the surface of the soil has been deduced and compared with the annual wave of the dally mean air temperature and the differences in the means, amplitudes, and phase displacements have been discussed.

Sampling Anopheles arabiensis, A. gambiae sensu lato and A. funestus (Diptera: Culicidae) with CDC light-traps near a rice irrigation area and a sugarcane belt in western Kenya

1994 ◽  
Vol 84 (3) ◽  
pp. 319-324 ◽  
Author(s):  
A.K. Githeko ◽  
M.W. Service ◽  
C.M. Mbogo ◽  
F.A. Atieli ◽  
F.O. Juma
Keyword(s):  
Anopheles Arabiensis ◽  
Communicable Disease ◽  
Light Trap ◽  
Anopheles Funestus ◽  
Malaria Vectors ◽  
Light Traps ◽  
Western Kenya ◽  
Specific Variation ◽  
Species Specific ◽  
Center Light

AbstractCDC (Communicable Disease Center) light-traps were compared with human-bait collections as an alternative method for sampling malaria vectors in two villages of western Kenya. The numbers of Anopheles funestus Giles and Anopheles gambiae sensu lato Giles in CDC light-trap collections were significantly correlated to the numbers caught in human-bait collections, but in Anopheles arabiensis Patton the two collections were not significantly correlated. Most of the female vectors collected in the traps were unfed. Parity of A. arabiensis collected in CDC light-traps (44.3%) was significantly lower than the rate obtained from females caught on human-bait (54.5%). Although CDC light-traps provide a cheap and convenient method for collecting vectors, further studies should nevertheless be undertaken to determine the influence of species-specific variation in the sizes and age-structure of collections because such variations can affect the epidemiological interpretation of the data.

A weighted coefficient model for estimation of Australian daily soil temperature at depths of 5cm to 100cm based on air temperature and rainfall

Soil Research ◽  
2011 ◽  
Vol 49 (4) ◽  
pp. 305 ◽  
Author(s):  
Brian Horton ◽  
Ross Corkrey
Keyword(s):  
Soil Temperature ◽  
Air Temperature ◽  
Cross Validation ◽  
Soil Depth ◽  
Mean Square ◽  
Air Temperatures ◽  
Proposed Model ◽  
Soil Temperatures ◽  
Weather Stations ◽  
Fold Cross Validation

Soil temperatures are related to air temperature and rainfall on the current day and preceding days, and this can be expressed in a non-linear relationship to provide a weighted value for the effect of air temperature or rainfall based on days lag and soil depth. The weighted minimum and maximum air temperatures and weighted rainfall can then be combined with latitude and a seasonal function to estimate soil temperature at any depth in the range 5–100 cm. The model had a root mean square deviation of 1.21–1.85°C for minimum, average, and maximum soil temperature for all weather stations in Australia (mainland and Tasmania), except for maximum soil temperature at 5 and 10 cm, where the model was less precise (3.39° and 2.52°, respectively). Data for this analysis were obtained from 32–40 Bureau of Meteorology weather stations throughout Australia and the proposed model was validated using 5-fold cross-validation.

scholarly journals Daily air temperature estimation on glacier surfaces in the Tibetan Plateau using MODIS LST data

2018 ◽  
Vol 64 (243) ◽  
pp. 132-147 ◽  
Author(s):  
HONGBO ZHANG ◽  
FAN ZHANG ◽  
GUOQING ZHANG ◽  
YAOMING MA ◽  
KUN YANG ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Air Temperature ◽  
Lapse Rate ◽  
The Tibetan Plateau ◽  
Mean Square ◽  
Night Time ◽  
Glacier Surface ◽  
Temperature Estimation ◽  
Air Temperatures ◽  
Air Temperature Estimation

ABSTRACTThe MODerate resolution Imaging Spectroradiometer (MODIS) land surface temperature (LST) data have been widely used for air temperature estimation in mountainous regions where station observations are sparse. However, the performance of MODIS LST in high-elevation glacierized areas remains unclear. This study investigates air temperature estimation in glacierized areas based on ground observations at four glaciers across the Tibetan Plateau. Before being used to estimate the air temperature, MODIS LST data are evaluated at two of the glaciers, which indicates that MODIS night-time LST is more reliable than MODIS daytime LST data. Then, linear models based on each of the individual MODIS LST products from two platforms (Terra and Aqua) and two overpasses (night-time and daytime) are built to estimate daily mean, minimum and maximum air temperatures in glacierized areas. Regional glacier surface (RGS) models (mean /-mean-square differences: 3.3, 3.0 and 4.8°C for daily mean, minimum and maximum air temperatures, respectively) show higher accuracy than local non-glacier surface models (mean root-mean-square differences: 4.2, 4.7 and 5.7°C). In addition, the RGS models based on MODIS night-time LST perform better to estimate daily mean, minimum and maximum air temperatures than using temperature lapse rate derived from local stations.

Temperature of upland and peatland soils in a north central Minnesota forest

1998 ◽  
Vol 78 (3) ◽  
pp. 493-509 ◽  
Author(s):  
Dale S. Nichols
Keyword(s):  
Soil Temperature ◽  
Air Temperature ◽  
Black Spruce ◽  
Biological Activities ◽  
Cold Weather ◽  
Peat Soils ◽  
North Central ◽  
Air Temperatures ◽  
Soil Temperatures ◽  
Aspen Forest

Soil temperature strongly influences physical, chemical, and biological activities in soil. However, soil temperature data for forest landscapes are scarce. For 6 yr, weekly soil temperatures were measured at two upland and four peatland sites in north central Minnesota. One upland site supported mature aspen forest, the other supported short grass. One peatland site was forested with black spruce, one supported tall willow and alder brush, and two had open vegetation — sedges and low shrubs. Mean annual air temperature averaged 3.6 °C. Mean annual soil temperatures at 10- to 200-cm depths ranged from 5.5 to 7.6 °C among the six sites. Soils with open vegetation, whether mineral or peat, averaged about 1 °C warmer annually and from 2 to 3 °C warmer during summer than the forested soils. The tall brush peatland was cooler than all other sites due to strong groundwater inputs. The mineral soils warmed more quickly in the spring, achieved higher temperatures in the summer, and cooled more quickly in the fall than the peat soils; however, the greatest temperature differences between mineral and peat soils occurred at or below 50 cm. In the upper 20 cm, vegetation and groundwater had greater effects on temperature than did soil type (mineral or peat). Summer soil temperatures were higher, relative to air temperature, during periods of greater precipitation. This effect was minimal at upland sites but substantial in the peatlands. In spite of the persistent sub-freezing air temperatures typical of Minnesota winters, significant frost developed in the soils only in those years when severe cold weather arrived before an insulating cover of snow had accumulated. Key words: Soil temperature, vegetation effects, forest soils, groundwater, peatlands

Effets de la scarification du site sur le micro-environnement

1980 ◽  
Vol 10 (4) ◽  
pp. 476-482 ◽  
Author(s):  
André P. Plamondon ◽  
Denis C. Ouellet ◽  
Gaston Déry
Keyword(s):  
Soil Water ◽  
Air Temperature ◽  
Soil Surface ◽  
The Other ◽  
Maximum Temperature ◽  
Soil Water Tension ◽  
Air Temperatures ◽  
Soil Temperatures ◽  
Water Tension ◽  
Minimum Air Temperature

Soil and air temperatures, and soil water tension were measured at two sites from June 1972 to August 1973 in order to determine the effect of scarification. This study is part of a project concerning yellow birch regeneration. The minimum air temperature at 30 cm height and at the soil surface were, respectively, 0.5 and 1.0 °C higher at the scarified site; on the other hand, the maximum temperature at 30 cm was lower. The soil temperatures during the summer were 2 to 4 °C higher at the scarified site according to the level considered. Soil water tension was much lower in the scarified station between 0 and 15 cm depth, but the effect decreased during the second summer of the study.

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