scholarly journals Winter Conditions Correlate with Phytophthora alni Subspecies Distribution in Southern Sweden

2015 ◽  
Vol 105 (9) ◽  
pp. 1191-1197 ◽  
Author(s):  
Miguel A. Redondo ◽  
Johanna Boberg ◽  
Christer H. B. Olsson ◽  
Jonàs Oliva
Keyword(s):  
Laboratory Experiments ◽  
Alnus Glutinosa ◽  
Climatic Conditions ◽  
Southern Sweden ◽  
Black Alder ◽  
Forest Pathogen ◽  
Winter Conditions ◽  
Winter Temperatures ◽  
Major River ◽  
Highly Correlated

During the last century, the number of forest pathogen invasions has increased substantially. Environmental variables can play a crucial role in determining the establishment of invasive species. The objective of the present work was to determine the correlation between winter climatic conditions and distribution of two subspecies of the invasive forest pathogen Phytophthora alni: P. alni subspp. alni and uniformis killing black alder (Alnus glutinosa) in southern Sweden. It is known from laboratory experiments that P. alni subsp. alni is more pathogenic than P. alni subsp. uniformis, and that P. alni subsp. alni is sensitive to low temperatures and long frost periods. By studying the distribution of these two subspecies at the northern limit of the host species, we could investigate whether winter conditions can affect the geographical distribution of P. alni subsp. alni spreading northward. Sixteen major river systems of southern Sweden were systematically surveyed and isolations were performed from active cankers. The distribution of the two studied subspecies was highly correlated with winter temperature and duration of periods with heavy frost. While P. alni subsp. uniformis covered the whole range of temperatures of the host, P. alni subsp. alni was recovered in areas subjected to milder winter temperatures and shorter frost periods. Our observations suggest that winter conditions can play an important role in limiting P. alni subsp. alni establishment in cold locations, thus affecting the distribution of the different subspecies of P. alni in boreal regions.

scholarly journals Ecological features of flowers and the amount of pollen released in Corylus avellana (L.) and Alnus glutinosa (L.) Gaertn.

2012 ◽  
Vol 61 (1) ◽  
pp. 33-39 ◽  
Author(s):  
Krystyna Piotrowska
Keyword(s):  
Pollen Grains ◽  
Alnus Glutinosa ◽  
Corylus Avellana ◽  
Climatic Conditions ◽  
Black Alder ◽  
Ecological Features ◽  
Atmospheric Pollen ◽  
Pollen Seasons ◽  
The Common ◽  
Corylus Avellana L

Hazel and alder bloom as one of the first plants in climatic conditions of Poland. In the present study, detailed observations were made of the structure of flowers of <i>Corylus avellana</i> L. and <i>Alnus glutinosa</i> (L.) Gaertn. Pollen yield of the abovementioned species was determined. The number of pollen grains in the theca, anther, flower and inflorescence was calculated. A comparison was made of the number of pollen grains of these taxa recorded during the atmospheric pollen seasons analysed over a period of 8 years in the conditions of Lublin. The study demonstrates that pollen yield of the common hazel inflorescence was 66 mg, whereas for black alder it was 120 mg. It was found that the number of pollen grains produced by the alder inflorescence was 2.2 times higher than by the hazel inflorescence. The atmospheric pollen season of the studied plant taxa was recorded at similar dates, but alder pollen was in much larger concentrations.

scholarly journals Reconstructing Late Pleistocene paleoclimate at the scale of human behavior: an example from the Neandertal occupation of La Ferrassie (France)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sarah Pederzani ◽  
Vera Aldeias ◽  
Harold L. Dibble ◽  
Paul Goldberg ◽  
Jean-Jacques Hublin ◽  
...  
Keyword(s):  
Human Behavior ◽  
Late Pleistocene ◽  
Tooth Enamel ◽  
Climatic Conditions ◽  
Climatic Data ◽  
Human Scale ◽  
Winter Temperatures ◽  
Archaeological Materials ◽  
Climatic Records

AbstractExploring the role of changing climates in human evolution is currently impeded by a scarcity of climatic information at the same temporal scale as the human behaviors documented in archaeological sites. This is mainly caused by high uncertainties in the chronometric dates used to correlate long-term climatic records with archaeological deposits. One solution is to generate climatic data directly from archaeological materials representing human behavior. Here we use oxygen isotope measurements of Bos/Bison tooth enamel to reconstruct summer and winter temperatures in the Late Pleistocene when Neandertals were using the site of La Ferrassie. Our results indicate that, despite the generally cold conditions of the broader period and despite direct evidence for cold features in certain sediments at the site, Neandertals used the site predominantly when climatic conditions were mild, similar to conditions in modern day France. We suggest that due to millennial scale climate variability, the periods of human activity and their climatic characteristics may not be representative of average conditions inferred from chronological correlations with long-term climatic records. These results highlight the importance of using direct routes, such as the high-resolution archives in tooth enamel from anthropogenically accumulated faunal assemblages, to establish climatic conditions at a human scale.

scholarly journals Glossiness Evaluation of Coated Wood Surfaces as Function of Varnish Type and Exposure to Different Conditions

Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 558
Author(s):  
Emilia-Adela Salca ◽  
Tomasz Krystofiak ◽  
Barbara Lis ◽  
Salim Hiziroglu
Keyword(s):  
Artificial Aging ◽  
Chemical Resistance ◽  
Heat Exposure ◽  
Value Added ◽  
Alnus Glutinosa ◽  
Practical Applications ◽  
Black Alder ◽  
Structural Differences ◽  
Wood Surfaces ◽  
Water Borne

The objective of this study was to evaluate the glossiness of black alder wood (Alnus glutinosa L.) samples coated with two varnish types as a function of exposure to dry heat and artificial aging. The chemical resistance of the coated samples to cold liquids was also evaluated. Based on the findings in this work, it appears that the varnish types and their structural differences influenced the overall glossiness of the coated samples. The UV varnish exhibited higher gloss values than those coated with the water-borne product within the range of silky gloss and silky matte grades. The heat exposure influenced the surface glossiness of the UV-coated samples more than the samples coated with water-borne varnish. The overall gloss values of the samples decreased with the exposure time to artificial aging, resulting in no layer cracks. The cold household liquids left less visible traces on the surfaces and alcohol was found to be the strongest agent. This study could have practical applications in the furniture industry to produce value-added furniture units according to their specific conditions of indoor use.

A bioclimatic index of human survival times in the Antarctic

Polar Record ◽  
1987 ◽  
Vol 23 (147) ◽  
pp. 651-659 ◽  
Author(s):  
C. R. de Freitas ◽  
L. V. Symon
Keyword(s):  
Core Temperature ◽  
Climatic Conditions ◽  
Survival Times ◽  
Climatological Data ◽  
Human Survival ◽  
Winter Conditions ◽  
Normal Core ◽  
Bioclimatic Index ◽  
Extreme Cold ◽  
The Antarctic

AbstractAn index of human ‘survival time outdoors in extreme cold’ (STOEC) has been developed, using body-atmosphere energy budget modelling procedures. The index, which is applicable in places like Antarctica where only limited climatological data are available, is based on the calculated rate of fall of core temperature from 37°C to 27°C of a standard inactive healthy subject in full polar clothing.Applied to data from 12 Antarctic stations it indicates relative severity of their mean and extreme climatic conditions. The severest winter conditions become lifethreatening after only about 20 minutes. At most stations in winter, exposure outdoors for more than two hours would be dangerous. Conditions at all coastal stations in summer are mildenough to allow a normal core temperature to be maintained. The index has many applications, for example estimating likely survival times of immobilized accident victims and guidelines for duration of work periods outside.

scholarly journals Response of black alder (Alnus glutinosa (L.) Gaertn.) to selective thinning of various intensities

2020 ◽  
Vol 144 (7-8) ◽  
pp. 378-378
Author(s):  
Simon Lendvai ◽  
Jurij Diaci ◽  
Dušan Roženbergar
Keyword(s):  
Alnus Glutinosa ◽  
Black Alder

Područje poplavnih šuma crne johe (Alnus glutinosa (L.) Gaertn.) u Sloveniji čini samo 0,4 % (približno 4708 ha) ukupne površine šumskog zemljišta (Čater i sur., 2001.). Veći kompleks takvih sastojina u Sloveniji su Črni i Polanski Log, a istraživanje je provedeno na području potonjeg (slika 1). Kako čiste sastojine johe odlikuju brojne specifičnosti, potrebno im je prilagoditi šumskouzgojne postupke. Da bi se utvrdio odgovarajući intenzitet prorjede takvih sastojina, 1967. godine u Polanskom Logu postavljene su pokusne plohe. Od tada do 2018. godine na plohama je izvršeno pet do sedam mjerenja. Sva stabla na plohama su bila obrojčana. Izvršeno je mjerenje prsnih promjera i procjena sljedećih elemenata na stablima: pripadnost etaži, vitalnost, uzgojna perspektiva, uzgojna uloga, duljina krošnje i kvaliteta (tablica 3). Svaka ploha bila je podijeljena u tri polja (40 x 50 m) s različitim metodama rada: bez intervencije, umjereno i intenzivno prorjeđivanje. Uzgojni postupci koji su poduzeti tijekom praćenja pokusa prikazani su u tablici 2. Danas su te sastojine u zreloj fazi razvoja, stoga smo u ovom radu analizirali reakcije crne johe na različite intenzitete prorjeđivanja i dobivene rezultate usporedili s preporukama autora tradicionalnih uzgojnih modela i modela koji se temelje na situacijskoj njezi šuma. Ustanovili smo da se na plohama s intenzivnim prorjeđivanjem gustoća sastojine koja je u dobi između 50 i 70 godina i na kraju je ophodnje kreće od 295 do 690 kom/ha (slika 3), dok se na plohama bez intervencije ova vrijednost kreće u rasponu od 370 do 790 kom/ha. Drvne zalihe u istom su se razdoblju kretale u rasponu od 277 do 458 m<sup>3</sup>/ha na plohama s intenzivnim prorjeđivanjem, dok su na plohama bez intervencije bile veće, u rasponu od 309 do 516 m<sup>3</sup>/ha (slika 4). U to su se doba temeljnice nalazile u rasponu između 23 i 41 m<sup>2</sup>/ha na plohama s intenzivnim prorjeđivanjem, a na plohama bez intervencije u rasponu od 26 do čak 51 m<sup>2</sup>/ha (slika 5). Tijekom cijelog razdoblja praćenja ploha, stabla su, bez obzira na metodu rada, narasla za tri do četiri debljinska stupnja (slika 2). Na plohama s umjerenim prorjeđivanjem i onima bez intervencije, debljinski prirast stabala bio je skoro jednak (0,33 cm godišnje) (slika 6). Statistički je značajan veći debljinski prirast stabala na plohama s jako intenzivnim prorjeđivanjem (0,37 cm godišnje). Debljinski prirast dominantnih stabala bio je nešto veći, od 0,46 cm godišnje na plohama bez intervencije do 0,50 cm godišnje na plohama s jako intenzivnim prorjeđivanjem, ali statistički značajne razlike između metoda rada nisu utvrđene (slika 6). Međutim, otkrili smo da kod dominantnih stabala ne postoje statistički značajne razlike s obzirom na njihovu slojevitost, vitalnost, tendenciju, dužinu krošnje i kvalitete s obzirom na korištenu metodu rada. U usporedbi s uzgojnim modelima koji su se koristili za manji broj odabranih stabla, gustoća i temeljnica ispitivanih sastojina je znatno veća, a debljinski prirast manji. Autori tradicionalnih i modela s manjim brojem odabranih stabala zagovaraju rano prorjeđivanje takvih sastojina (tablica 1). Veće razlike nastaju u konačnom broju stabala po hektaru i u intenzitetu intervencije. Razlog malog debljinskog prirasta i razlike između metoda rada na našim plohama pripisali smo nedovoljnom intenzitetu i djelomično nedosljednoj provedbi postupka prorjeđivanja. Ipak, ukazala se potreba za intenzivnim prorjeđivanjem i pospješivanjem rasta stabala najvećeg prsnog promjera, vitalnosti i tendencije, lijepo oblikovane i duge krošnje (slika 7, slika 8).

scholarly journals Effects of botanical antifeedants on Melolontha melolontha grub feeding on Scots pine roots

2014 ◽  
Vol 56 (3) ◽  
pp. 135-140 ◽  
Author(s):  
Iwona Skrzecz ◽  
Alicja Sowińska ◽  
Wojciech Janiszewski
Keyword(s):  
Pinus Sylvestris ◽  
Scots Pine ◽  
Pure Water ◽  
Alnus Glutinosa ◽  
Open Area ◽  
Antifeedant Activity ◽  
Tree Roots ◽  
Black Alder ◽  
Melolontha Melolontha ◽  
Extent Of Damage

Abstract The aim of the study was to evaluate the possibility of using botanic antifeedants to reduce the damage caused by Melolontha spp. grubs. To achieve the objective, the experiments were established in semi-field conditions to estimate the antifeedant activity of rutin, quercetin (flavonoids from buckwheat Fagopyrum esculentum) and an extract from black alder Alnus glutinosa leaves against Melolontha melolontha grubs. The grubs were placed individually in the pots with a soil in which 2 year old Pinus sylvestris trees were planted. The pots were put in garden pavilions placed in the open area. Then the soil in the pots were watered with the emulsions of rutin, quercetin, an extract from A. glutinosa leaves, and with pure water-comparative variant. After 4 months, the weight and mortality of grubs were compared, as well as the weight of tree roots in all pots. There was no effect of the antifeedants on the development and extent of damage caused by M. melolontha grubs. The results do not indicate the use of botanic antifeedants in the protection of forests against the cockchafer grubs

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