Climatic determinants of berry crops in the boreal forest of the southwestern Yukon

C. J. Krebs; R. Boonstra; K. Cowcill; A. J. Kenney

doi:10.1139/b09-013

Climatic determinants of berry crops in the boreal forest of the southwestern Yukon

Botany ◽

10.1139/b09-013 ◽

2009 ◽

Vol 87 (4) ◽

pp. 401-408 ◽

Cited By ~ 34

Author(s):

C. J. Krebs ◽

R. Boonstra ◽

K. Cowcill ◽

A. J. Kenney

Keyword(s):

Boreal Forest ◽

Common Species ◽

Summer Temperature ◽

Weather Variables ◽

Predictive Equations ◽

Empetrum Nigrum ◽

Berry Crops ◽

Study Interval ◽

One Year ◽

Shepherdia Canadensis

Berry crops in the southwestern Yukon were quantified from 1997 to 2008 at 10 locations along 210 km of the Alaska and Haines highways. We tested the hypothesis that the size of berry crops could be predicted from spring and summer temperature and rainfall of years t, t–1 (1 year prior), and t–2 (2 years prior). Six common species were studied in the boreal forest of the Kluane region: Arctostaphylos rubra (Rehd. & Wils.) Fern., Arctostaphylos uva-ursi (L.) Spreng. s.l., Empetrum nigrum L., Vaccinium vitis-idaea L., Geocaulon lividum (Richards) Fern, and Shepherdia canadensis (L.) Nutt.. For the first five species we counted berries on fixed 40 cm × 40 cm quadrats to obtain an index of berry production for the Kluane region for each of the 12 years, and for S. canadensis we counted berries on two tagged branches of 10 bushes at each location. Stepwise multiple regressions were utilized to predict the size of berry crops for each species. For all species, predictive equations could explain statistically 80%–96% of the variation in berry crops. Different weather variables characterized each plant species, and there was no common weather regression that could explain the variation in berry crops in all species. Rainfall and temperature from years t–1 and t–2 were typically the significant predictors. There was no indication of a periodicity in berry production, and 43%–60% of the quadrats counted had large berry crops at one year intervals, while other quadrats never had a high crop during the study interval.

Download Full-text

Major postglacial summer temperature changes in the central coniferous boreal forest of Quebec (Canada) inferred using chironomid assemblages

Journal of Quaternary Science ◽

10.1002/jqs.3022 ◽

2018 ◽

Vol 33 (4) ◽

pp. 409-420 ◽

Cited By ~ 8

Author(s):

Lisa Bajolle ◽

Isabelle Larocque-Tobler ◽

Emmanuel Gandouin ◽

Martin Lavoie ◽

Yves Bergeron ◽

...

Keyword(s):

Boreal Forest ◽

Summer Temperature ◽

Temperature Changes ◽

Chironomid Assemblages ◽

Coniferous Boreal Forest

Download Full-text

Characterization of free amino acids, bacteria and fungi in size-segregated atmospheric aerosols in boreal forest: seasonal patterns, abundances and size distributions

10.5194/acp-2017-620 ◽

2017 ◽

Author(s):

Aku Helin ◽

Outi-Maaria Sietiö ◽

Jussi Heinonsalo ◽

Jaana Bäck ◽

Marja-Liisa Riekkola ◽

...

Keyword(s):

Amino Acids ◽

Boreal Forest ◽

Atmospheric Aerosols ◽

Free Amino Acids ◽

Free Amino ◽

Meteorological Parameters ◽

Close Relationship ◽

Temperature Radiation ◽

Bacteria And Fungi ◽

One Year

Abstract. Bioaerosols are ubiquitous in the atmosphere and constitute ~ 30 % of atmospheric aerosol particle mass in sizes > 1 μm. Bioaerosol components, such as bacteria, fungi and pollen, may affect the climate by acting as could-active particles, thus having an effect on cloud and precipitation formation processes. In this study, size-segregated aerosol samples ( 10 μm) were collected in boreal forest (Hyytiälä, Finland) during one year and analyzed for free amino acids (FAAs), DNA concentration and microorganism (bacteria, Pseudomonas and fungi). Measurements were performed using tandem mass spectrometry, spectrophotometry and qPCR, respectively. Meteorological parameters and statistical analysis were used to study their atmospheric implication for results. Distinct annual patterns of bioaerosol components were observed, late spring and autumn being seasons of dominant occurrence. Elevated abundances of FAAs and bacteria were observed during the local pollen season, whereas fungi were observed at highest level during autumn. Meteorological parameters, such as air and soil temperature, radiation and rainfall were observed to possess close relationship with bioaerosol abundances on an annual scale.

Download Full-text

Phenology, Seasonal Abundance, and Host-Plant Association of Spittlebugs (Hemiptera: Aphrophoridae) in Vineyards of Northwestern Italy

Insects ◽

10.3390/insects12111012 ◽

2021 ◽

Vol 12 (11) ◽

pp. 1012

Author(s):

Nicola Bodino ◽

Stefano Demichelis ◽

Anna Simonetto ◽

Stefania Volani ◽

Matteo Alessandro Saladini ◽

...

Keyword(s):

Host Plant ◽

Late Summer ◽

Common Species ◽

Seasonal Abundance ◽

Cultivated Plants ◽

Plant Association ◽

Egg Hatching ◽

Field Surveys ◽

One Year ◽

Cover Up

Spittlebugs (Hemiptera: Aphrophoridae) are the vectors of the bacterium Xylella fastidiosa (Xf) in Europe. Xf may cause severe epidemics in cultivated plants, including grapevines. To assess the threat represented by the bacterium to grapevines, detailed information on the vectors’ phenology, density, and ecology in vineyards is needed. The aim of the present work was to describe spittlebug diversity, phenology, and host-plant association in the vineyard agroecosystem. Two separate field surveys of nymphal and adult spittlebug populations, i.e., a two-year survey of a single site and a one-year survey of three sites, were performed in vineyards of northwestern Italy in three consecutive years. Philaenus spumarius was the most common species, reaching average nymph densities on herbaceous cover up to 60–130 nymphs/m2. Adults were sampled on grapevines from May to September, with a peak in June (up to 0.43 insects/sweep). Herbaceous cover was colonized after egg hatching and in late summer for oviposition, while wild woody hosts represented a refuge during summer. The results show that spittlebugs can reach high population levels in vineyards, at least in the areas where the ground is covered by herbaceous plants for the whole season and the use of insecticides is moderate. The extended presence of P. spumarius adults on grapevines represents a serious risk factor for the spread of Xf. The scenarios of Xf establishment in vineyards in northwestern Italy and Europe are discussed in relation to the abundance, phenology, and plant association of spittlebugs.

Download Full-text

The effect of winter weather on timber truck tare weights

Silva Fennica ◽

10.14214/sf.10385 ◽

2020 ◽

Vol 54 (4) ◽

Author(s):

Perttu Anttila ◽

Tuomas Nummelin ◽

Kari Väätäinen ◽

Juha Laitila

Keyword(s):

Regression Models ◽

Capacity Utilization ◽

Weather Data ◽

Weather Variables ◽

Monthly Basis ◽

Maximum Loss ◽

Payload Capacity ◽

One Year ◽

Increasing Precipitation ◽

Very High

In wintertime, the payload capacity of a timber truck is reduced by snow that accumulates on the structures of the truck. The aim of this study was to quantify the potential payload loss due to snow and winter accessories and to predict the loss with weather variables. Tare weights of eight timber trucks were collected at mill receptions in Finland over a one-year period. Monthly and annual loss of potential payload was estimated using the tare measurements in summer months as a reference. Each load was also connected with weather data at the location and time of delivery and payload loss explained by the weather data with the aid of regression models. The maximum loss of payload varied between 1560 kg and 3100 kg. On a monthly basis, the highest losses occurred in January, when the median values varied between 760 kg and 2180 kg. Over the year, the payload loss ranged between the trucks from 0.5% to 1.5% (from 1.9% and 5.1% in January) of the total number of loads in the study. Payload loss was found to increase with decreasing temperature, increasing relative humidity and increasing precipitation. Although the average payload loss was not very high, the biggest losses occur just during the season of highest capacity utilization. Big differences were also found in the tare weights between the trucks. The results of the study give incentive to develop truck and trailer structures that reduce the adherence of snow.

Download Full-text

Evaluation of the Hargreaves-Samani Method for Estimating Reference Evapotranspiration with Ground and Gridded Weather Data Sources

Applied Engineering in Agriculture ◽

10.13031/aea.13363 ◽

2019 ◽

Vol 35 (5) ◽

pp. 823-835

Author(s):

Rogério De Souza Nóia Júnior ◽

Clyde William Fraisse ◽

Vinicius Andrei Cerbaro ◽

Mauricio Alex Z. Karrei ◽

Noemi Guindin

Keyword(s):

United States ◽

Production Systems ◽

Reference Evapotranspiration ◽

The United States ◽

Weather Data ◽

Data Sets ◽

Weather Variables ◽

Method Performance ◽

Main Input ◽

One Year

Abstract. Methods of estimating evapotranspiration require weather variables as their main input data. Thus, the lack of full weather data sets is one of the main challenges for evaluating and mitigating the effects of climate variability and climate change on agricultural production systems. The Hargreaves-Samani method (HS) is one of the ways to estimate reference evapotranspiration (ETo) when only temperature observations are available, which is a common situation in many agricultural enterprises. Another possible option for regions not served by weather stations is the use of gridded weather data (GWD). Based on that, the main objective of this study was to evaluate the performance of the HS method to estimate ETo in different regions of the United States, as well as to assess the suitability of two gridded weather data (PRISM and NOAA-RTMA) sources to estimate ETo by comparing the results obtained to ETo estimated by the Penman-Monteith (FAO-PM) method, which is the recommended methodology by FAO Irrigation and Drainage Paper 56 when all weather variables are available. Weather observations were obtained for 17 locations across the United States representing regions with subtropical humid and semi-arid continental climates, considering the period of one year (2017). These observations were used to estimate daily ETo with the HS and Penman-Monteith methods. Our results demonstrated that the HS method performance varied according to the location and month of the year. Due to the high relative humidity (RH) during the winter, and high air temperature (Ta) during the summer, the locations selected in the state of Florida, presented the worst performance. The HS method performed well in many other locations such as Froid – MT. Also, the estimation of ETo by HS method and by using PRISM and NOAA-RTMA gridded weather databases showed a good agreement with the ETo estimated by FAO-PM based on weather station observations. Keywords: Penman-Monteith, PRISM, RTMA, Water Management.

Download Full-text

Phenotypic and genotypic characterization of Candida species isolated from candideamia in Iran

Current Medical Mycology ◽

10.18502/cmm.4.2.64 ◽

2018 ◽

Vol 4 (2) ◽

Cited By ~ 9

Author(s):

Seyedeh Zahra Sadrossadati ◽

Mohammad Ghahri ◽

Abbas Ali Imani Fooladi ◽

Shirin Sayyahfar ◽

Sedigheh Beyraghi ◽

...

Keyword(s):

Species Identification ◽

Candida Species ◽

Tween 80 ◽

Common Species ◽

Antifungal Drugs ◽

Molecular Methods ◽

Pcr Rflp ◽

Appropriate Therapy ◽

One Year ◽

Phenotypic Methods

Background and Purpose: Candidemia is one of the most important fungal infections caused by Candida species. Infections and mortality caused by Candida species have been on a growing trend during the past two decades. The resistance of yeasts to antifungal drugs and their epidemiological issues have highlighted the importance of accurately distinguishing the yeasts at the species level. The technique applied for yeast identification should be fast enough to facilitate the imminent initiation of the appropriate therapy. Candidemia has not been studied comprehensively in Iran yet. Regarding this, the current study aimed to assess the epidemiology of candidemia at Tehran hospitals and compare the results with the previous findings. Materials and Methods: This study was conducted on 204 positive blood cultures obtained from 125 patients hospitalized in several hospitals located in Tehran, Iran, within a period of 13 months. The yeast isolation and species identification were accomplished using several phenotypic methods (i.e., production of germ tube in human serum, culture on CHROMagar Candida, and Corn meal agar containing Tween 80) and molecular methods, such as polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). In addition, unknown cases were subjected to PCR sequencing. These methods were then compared in terms of accuracy, sensitivity, and speed of identification. Results: According to the results, C. albicans (62.4%) was the most common isolate, followed by C. parapsilosis (n=36, 17.5%), C. glabrata (n=18, 8.8%), C. tropicalis (n=13, 6.3%), Trichosporon asahii (n=3, 1.5%), C. kefyr (n=2, 1.0%), C. lusitaniae (n=2, 1.0%), C. intermedia (n=1, 0.5%), C. guilliermondii (n=1, 0.5%), and C. krusei (n=1, 0.5%), respectively. Conclusion: As the findings indicated, the most common species causing candidemia were C. albicans, C. parapsilosis, and C. glabrata, respectively. Children less than one year old and people with cancer were at higher risk for candidemia, compared to other groups. Moreover, phenotypic and molecular methods resulted in the identification of 65.2% and 96.6% of the isolates, respectively. Consequently, PCR-RFLP could be concluded as a more favorable technique for species identification. Keywords: Candidemia, Blood culture, Epidemiology, PCR-RFLP

Download Full-text

Long-Term Glacier Mass-Balance Investigations in Svalbard, 1950–88

Annals of Glaciology ◽

10.3189/s0260305500008351 ◽

1990 ◽

Vol 14 ◽

pp. 102-106 ◽

Cited By ~ 27

Author(s):

Jon Ove Hagen ◽

Olav Liestøl

Keyword(s):

Mass Balance ◽

Winter Precipitation ◽

Summer Temperature ◽

Glacier Mass Balance ◽

Climatic Warming ◽

Equilibrium Line Altitude ◽

Stable Conditions ◽

The Mean ◽

One Year

Mass-balance investigations on glaciers in Svalbard at high latitudes (78°N) show that the ice masses have been steadily decreasing during the period 1950–88. Detailed annual observations have been carried out on Brøggerbreen since 1966 and Lovénbreen since 1967. The mean specific net balances are −0.46 and −0.37 m year−1 water equivalent respectively. Only one year had positive net balance in this period. The cumulative mass lost in the period is then more than 10% of the volume in 1967. Zero net balance would be obtained if the summer temperature was lowered about 1°C or if the winter precipitation increased about 50%. There is a strong correlation between the net mass balance and the height of the equilibrium-line altitude (ELA). Because of the high amount of superimposed ice (10–30% of winter balance) stake readings are necessary to find the ELA. There is no sign of climatic warming through increased melting. The trend analysis of the data from the last 20 years shows stable conditions with a slight increase of the winter balance. The net balance is then slightly increasing and thus less negative than 20 years ago.

Download Full-text

Impact of indoor residual spraying on malaria transmission in the Moïssala health district, Chad

10.21203/rs.2.19781/v1 ◽

2019 ◽

Author(s):

Demba Kodindo Israël ◽

Diomba Dobar Abel ◽

Adoum Mahamat Oumar ◽

Moundai Tchonfinet ◽

Amen Nakebang Fadel ◽

...

Keyword(s):

Malaria Transmission ◽

Human Subjects ◽

Indoor Residual Spraying ◽

Common Species ◽

Health District ◽

Malaria Vectors ◽

Eastern Zone ◽

Short Period ◽

One Year ◽

The Impact

Abstract BackgroudMalaria is a major public health and development problem in Africa. In Chad in 2016, with 720 765 confirmed cases and 1 686 deaths, malaria is the main cause of consultations, hospitalizations and deaths in health facilities. A longitudinal entomological study was carried out from 07 to 24 December 2016 in the Moïssala health district. The objective of the study was to assess the impact of malaria transmission one year after two cycles of indoor residual spraying of 80% bendiocarb wettable powder (Ficam WP 80 W).MethodsTwo areas were defined for the study: the town of Dembo, located in the sprayed area, was chosen as the test town and Moïssala, located in the untreated area, was chosen as the control town. Two sampling methods were used: collection of resting endophilic fauna and direct capture of aggressive mosquitoes from human subjects. ResultsA total of 16 sessions of catches on human subjects totalling 32 man-nights were conducted and 160 rooms were sprayed per site. For 160 sprayed chambers per site, two anopheles were captured in Dembo compared to 547 in Moïssala. Three anophelian species have been morphologically identified. In Moïssala, An gambiae sl (An colluzzii : 96%, An gambiae : 4%), An funestus and An rufipes were captured at rest in the rooms and on human bait. In Dembo, the two anopheles, An colluzzii and An funestus were captured at rest in the rooms. On human bait as in endophilic fauna, An gambiae sp was the most common species in Moïssala. The aggressive anophelian density was zero in Dembo while it is 9 bites per man per night in Mosesala. Only Anopheles gambiae sp was found infected in aggressive wildlife. The sporozoite index of the aggressive fauna of An gambiae sp was 7.45%. Malaria transmission was estimated at 0.67 infected bites per man per night, or 244.55 infected bites per man per year. In endophilic fauna, An gambiae sp and An rufipes were the two species found infected in Moïssala with sporozoite indices of 6.70% (23/343) and 20% (2/10) respectively. However, in Dembo, neither of the two captured individuals was found infected.ConclusionsThe indoor residual spraying campaign in the eastern zone of the Moïssala health district has led to the collapse of the density and aggressiveness of malaria vectors. However, its evaluation over a short period of time is not sufficient to assess the impact of malaria transmission in this stable and highly endemic malaria zone.

Download Full-text

Control of the number of field slugs Deroceras agreste L. in the plantations of garden strawberry

BIO Web of Conferences ◽

10.1051/bioconf/20202506007 ◽

2020 ◽

Vol 25 ◽

pp. 06007

Author(s):

Marina Podgornaya ◽

Nadezhda Didenko ◽

Anfisa Vasilchenko ◽

Julia Kashchits ◽

Irina Mishchenko

Keyword(s):

Control Systems ◽

Pest Control ◽

Common Species ◽

Protection Systems ◽

Berry Crops ◽

Single Use ◽

Biological Effectiveness ◽

Krasnodar Region ◽

Control Variant

Slugs cause serious harm to nurseries and young plantations of fruit and berry crops in the Krasnodar region. On garden strawberries, the most common species is the field slug Deroceras agreste L., whose larvae damage ripe fruits and leaves, as well as contaminate them with their secretions and mucus, which leads to a decrease in the quality of seedlings and contributes to damage by secondary pests. In modern protection systems, the most commonly used pest control systems are molluscicides containing methaldehyde. The aim of our research was to assess the biological effectiveness of the molluscicides Sliznyakoff, G (60 g/kg methaldehyde) and Slizneed, G (60 g/kg methaldehyde) in controlling the abundance of field slugs in strawberry agrocenoses on the Clery variety. It was found that with an average number of phytophage larvae in the control variant (12.5-16.0 individuals / 10 m2), a single use of molluscicides causes 95.3 % mortality of D. agreste L. on the 7th day.

Download Full-text