Oak Pollen Research Articles

Development of a semi-mechanistic allergenic pollen emission model

Modeling pollen emission processes is crucial for studying the spatiotemporal distributions of airborne allergenic pollen. A semi-mechanistic emission model was developed based on mass balance of pollen grain fluxes in the surroundings of allergenic plants. The emission model considers direct emission and resuspension and accounts for influences of temperature, wind velocity, and relative humidity. Modules of this emission model have been developed and parameterized with multiple years of pollen count observations to provide pollen season onset and duration, hourly flowering likelihood, and vegetation coverage for oak and ragweed, as two examples. The simulated spatiotemporal pattern of pollen emissions generally follows the corresponding pattern of area coverage of allergenic plants and diurnal pattern of hourly flowering likelihood. It is found that oak pollen emissions start from the Southern part of the Contiguous United States (CONUS) in March and then shift gradually toward the Northern CONUS, with a maximum emission flux of 5.8 × 106 pollen/(m2 h). On the other hand, ragweed pollen emissions start from the Northern CONUS in August and then shift gradually toward the Southern CONUS. The mean ragweed emission flux during August to September can increase up to 2.4 × 106 pollen/(m2 h). This emission model is robust with respect to the input parameters for oak and ragweed. Qualitative evaluations of the model performance indicated that the simulated pollen emission is strongly correlated with the plant coverages and observed pollen counts. This model could also be applied to other pollen species given the relevant parameters.

The oak pollen concentration in the air of selected cities in Poland in 2018

This paper contains an analysis of oak pollen seasons in selected cities of Poland in 2018. Sampling sites were located in the following cities: Bialystok, Bydgoszcz, Cracow, Drawsko Pomorskie, Lublin, Olsztyn, Opole, Piotrkow Trybunalski, Sosnowiec, Szczecin, Warsaw, Wroclaw and Zielona Gora. The volumetric method was applied using the Burkard or Lanzoni trap. The pollen season was determined by the 98% method. The season started earliest in Sosnowiec (April 14th). The mean duration of the pollen season was 33 days. The highest pollen concentration (713 P/m3) was observed in Wroclaw (April 19th). The peak values were recorded between April 19th and May 1st in the different cities.

Behaviour of Quercus pollen in the air, determination of its sources and transport through the atmosphere of Mexico City and conurbated areas.

Pollen allergies have a remarkable clinical impact all over world. Quercus pollen is the main allergen in many parts of world. Due to the health impacts caused by exposure to oak pollen, the objectives of this study are to characterise the aerobiological behaviour of Quercus pollen and to determine its potential sources as well as their transport through the atmosphere of Mexico City and surrounding areas between January 2012 and June 2015. Airborne Quercus pollen monitoring was carried out simultaneously in five zones of Mexico City. The percentage of Quercus pollen of the total pollen collected from the air showed that the highest concentration was recorded in 2014, followed by 2012. The annual seasonal variation indicated that flowering and pollen emission into the atmosphere began between February and March. The maximum concentration of Quercus pollen was reached at Cuajimalpa. In 2012, the amount of pollen grains was distributed in March and April uniformly, whilst in 2014, the largest amount of pollen was concentrated in March. In 2012 and 2014 (years with the highest pollen concentrations), corresponding intraday variations were quite similar, with a low relative maximum in the morning and the highest concentrations in the evening. The largest values were recorded in 2014, and two processes can explain these. In the afternoon, pollen from secondary forest is carried by southwesterly converging winds, increasing the pollen concentration in Cuajimalpa. In the evening, there is an additional pollen contribution from primary forest via transport by NW winds.

When beggars are choosers-How nesting of a solitary bee is affected by temporal dynamics of pollen plants in the landscape.

Wild bees are declining in intensively farmed regions worldwide, threatening pollination services to flowering crops and wild plants. To halt bee declines, it is essential that conservation actions are based on a mechanistic understanding of how bee species utilize landscapes. We aimed at teasing apart how foraging resources in the landscape through the nesting season affected nesting and reproduction of a solitary bee in a farmland region. We investigated how availability of floral resources and potentially resource‐rich habitats surrounding nests affected nest provisioning and reproduction in the solitary polylectic bee Osmia bicornis. The study was performed in 18 landscape sectors dominated by agriculture, but varying in agricultural intensity in terms of proportion of organic crop fields and seminatural permanent pastures. Pasture‐rich sectors contained more oak (Quercus robur), which pollen analysis showed to be favored forage in early season. More oaks ≤100 m from nests led to higher proportions of oak pollen in nest provisions and increased speed of nest construction in early season, but this effect tapered off as flowering decreased. Late‐season pollen foraging was dominated by buttercup (Ranunculus spp.), common in various noncrop habitats. Foraging trips were longer with more oaks and increased further through the season. The opposite was found for buttercup. Oak and buttercup interacted to explain the number of offspring; buttercup had a positive effect only when the number of oaks was above the mean for the studied sectors. The results show that quality of complex and pasture‐rich landscapes for O. bicornis depends on preserving existing and generating new oak trees. Lignose plants are key early‐season forage resources in agricultural landscapes. Increasing habitat heterogeneity with trees and shrubs and promoting suitable late‐flowering forbs can benefit O. bicornis and other wild bees active in spring and early summer, something which existing agri‐environment schemes seldom target.

Does the increase in ambient CO2 concentration elevate allergy risks posed by oak pollen?

Oak pollen is a major respiratory allergen in Korea, and the distribution of oak trees is expected to increase by ecological succession and climate change. One of the drivers of climate change is increasing CO2, which is also known to amplify the allergy risk of weed pollen by inducing elevated allergenic protein content. However, the impact of CO2 concentration on tree pollen is not clearly understood due to the experimental difficulties in carrying out extended CO2 treatment. To study the response of pollen production of sawtooth oak trees (Quercus acutissima) to elevated levels of ambient CO2, three open-top chambers at the National Institute of Forest Science in Suwon, Korea were utilized with daytime (8am-6pm) CO2 concentrations of ambient (× 1.0, ~ 400ppm), × 1.4 (~ 560ppm), and × 1.8 (~ 720ppm) treatments. Each chamber had three sawtooth oak trees planted in September 2009. One or two trees per chamber matured to bloom in 2016. Five to six catkins were selected per tree and polyethylene bags were attached to collect pollen grains. The total number of catkins per tree was counted and the number and weight of pollen grains per catkin were measured. Oak allergen-Que a 1 (Allergon Co., Uppsala, Sweden)-was extracted and purified to make an ELISA kit by which the antigen levels in the pollen samples were quantified. Total pollen counts per tree of the × 1.4 and × 1.8 treatments showed significant increase of 353 and 1299%, respectively, from the × 1.0 treatment (p < 0.001). Allergenic protein contents at the × 1.4 and × 1.8 treatments also showed significant increase of 12 and 11%, respectively (p = 0.011). The × 1.8 treatment induced significant difference from the × 1.0 treatment in terms of pollen production and allergenic protein content, whereas the × 1.4 treatment showed mixed significance. In summary, the oak trees under the elevated CO2 levels, which are expected in the changing climate, produced significantly higher amount of pollen and allergenic protein than under the present air conditions.

Florida wildfires during the Holocene Climatic Optimum (9000–5000 cal yr BP)

Fire is a key ecological driver in terrestrial ecosystems of the southeastern United States. The combination of plant species composition and fire poses the possibility of positive feedback loops in a landscape. How fire regimes will change in the future with global warming is uncertain. To better understand the main factors that control fire, Holocene fire history was studied using macroscopic charcoal (as a fire proxy) in sediment cores from two shallow lakes in north Florida, USA. Following the onset of lacustrine sedimentation in the early Holocene, there was a 95% decline in average charcoal concentration, from 28.3 to 1.4 charcoal particles cm−3, at ~ 7500 cal yr BP in a 3.9-m core from Newnans Lake (basal age: 8870 cal yr BP). At ~ 7000 cal yr BP in a 5.4-m core from nearby Lochloosa Lake (basal age: 9280 cal yr BP), particle density declined by 99%, from 113.8 to 1.4 charcoal particles cm−3. These declines in charcoal concentration are not artifacts of changes in bulk sedimentation, i.e. dilution, but instead reflect lower charcoal production. Newnans Lake and Lochloosa Lake averaged ~ 8.93 and ~ 40.42 charcoal particles cm−3, respectively over their entire records. Pollen records from the two study lakes do not display the Quercus to Pinus shift during the Holocene Climatic Optimum (9000–5000 cal yr BP) observed previously in cores from many studied lakes in the region. Instead, pine pollen, as a percentage of total oak and pine pollen, was high (> 50%) through the entire Holocene. Pine and oak pollen counts and the variety of arboreal pollen, however, were lower in early Holocene deposits. No relation was found between pine and oak percentages and macroscopic charcoal quantity, i.e. before, during, or after charcoal peaks. There were, however, qualitative differences between pollen assemblages within charcoal-rich and charcoal-poor depth intervals. Early to middle Holocene sediments contained pollen of Quercus spp., Pinus spp., Ambrosia sp., Amaranthaceae, Cyperaceae and Poaceae. Late Holocene sediments contained hydric and mesic pollen types including Taxodium spp., Carya sp., Ilex sp., and Liquidambar styraciflua. The flat, poorly drained topography around both lakes played a role in shaping Holocene plant communities and probably explains why a Quercus-to-Pinus shift seen elsewhere in Florida did not occur in the study region.

Investigation of Primary Factors Affecting the Variation of Modeled Oak Pollen Concentrations: A Case Study for Southeast Texas in 2010

Oak pollen concentrations over the Houston-Galveston-Brazoria (HGB) area in southeastern Texas were modeled and evaluated against in-situ data. We modified the Community Multi-scale Air Quality (CMAQ) model to include oak pollen emission, dispersion, and deposition. The Oak Pollen Emission Model (OPEM) calculated gridded oak pollen emissions, which are based on a parameterized equation considering a plant-specific factor (C e ), surface characteristics, and meteorology. The simulation period was chosen to be February 21 to April 30 in the spring of 2010, when the observed monthly mean oak pollen concentrations were the highest in six years (2009-2014). The results indicated C e and meteorology played an important role in the calculation of oak pollen emissions. While C e was critical in determining the magnitude of oak pollen emissions, meteorology determined their variability. In particular, the contribution of the meteorology to the variation in oak pollen emissions increased with the oak pollen emission rate. The evaluation results using in-situ surface data revealed that the model underestimated pollen concentrations and was unable to accurately reproduce the peak pollen episodes. The model error was likely due to uncertainty in climatology-based C e used for the estimation of oak pollen emissions and inaccuracy in the wind fields from the Weather Research and Forecast (WRF) model.

Oak pollen in the air of Poland in 2017

The aim of the study was to compare the pollen season of oak in the cities of Bialystok, Bydgoszcz, Cracow, Katowice, Piotrkow Trybunalski, Lublin, Olsztyn, Opole, Szczecin, Warsaw, Wroclaw and Zielona Gora in 2017. Measurements were performed by the volumetric method (Hirst type pollen sampler). Seasonal Pollen Index (SPI) was estimated as the sum of daily average pollen concentrations in the given season. Pollen season was defined as the period in which 98% of the annual total catch occurred. The pollen season of oak started first in Szczecin, on the 1st April, and lasted till the end of May. At the latest pollen season ended in Olsztyn on the 1st June. However, in the most of other cities the season lasted till the end of May. The differences of pollen seasons duration were considerables from 28 to 56 days. The highest, record airborne concentration of 342 pollen grains/m3 was noted in Warsaw on the 17th May. The maximum values of seasonal pollen count occurred between of 11th and 20th May. The highest oak pollen allergen hazard occurred in 2017 in Piotrkow Trybunalski, Lublin and Warsaw

Evidence of Holocene climatic change and human impact in northwestern Yunnan Province: High-resolution pollen and charcoal records from Chenghai Lake, southwestern China

High-resolution pollen and charcoal records from Chenghai Lake, northwestern Yunnan Province of China, are presented in this study. These records reveal changes in climate and human activity since 8220 cal. yr BP, and the drivers of climatic change are further discussed based on spectral analysis of Tsuga and evergreen oak pollen percentages. The pollen record indicated that the climate in the low altitude area was relatively warm and moderately dry, whereas the climate in the high altitude area was relatively cool and humid during the period 8220–4670 cal. yr BP, corresponding to the Holocene climate optimum, although the seasonality of precipitation increased between 5180 and 4670 cal. yr BP. From 4670 to 3470 cal. yr BP, the temperature declined, and the precipitation and its seasonality decreased. Between 3470 and 1860 cal. yr BP, the temperature was still relatively low, and precipitation appeared to decrease further. At the same time, human activity represented by agricultural planting began to influence this study area, but the intensity of human activity was relatively weak. After 1860 cal. yr BP, the climate was gradually becoming drier and the intensity of human activity such as deforestation and slash-and-burn agriculture increased. Spectral analysis of Tsuga and evergreen oak pollen percentages shows statistically significant periodicities of ~1500 and ~200 years at the ≥95% confidence level, which suggests that insolation and feedback interactions on millennial to centennial scales are the primary forcing mechanisms of the southwest monsoon and past climatic change during the Holocene in northwestern Yunnan Province, southwestern China.

Impacts of oak pollen on allergic asthma in the United States and potential influence of future climate change.

Future climate change is expected to lengthen and intensify pollen seasons in the U.S., potentially increasing incidence of allergic asthma. We developed a proof‐of‐concept approach for estimating asthma emergency department (ED) visits in the U.S. associated with present‐day and climate‐induced changes in oak pollen. We estimated oak pollen season length for moderate (Representative Concentration Pathway (RCP) 4.5) and severe climate change scenarios (RCP8.5) through 2090 using five climate models and published relationships between temperature, precipitation, and oak pollen season length. We calculated asthma ED visit counts associated with 1994–2010 average oak pollen concentrations and simulated future oak pollen season length changes using the Environmental Benefits Mapping and Analysis Program, driven by epidemiologically derived concentration‐response relationships. Oak pollen was associated with 21,200 (95% confidence interval, 10,000–35,200) asthma ED visits in the Northeast, Southeast, and Midwest U.S. in 2010, with damages valued at $10.4 million. Nearly 70% of these occurred among children age <18 years. Severe climate change could increase oak pollen season length and associated asthma ED visits by 5% and 10% on average in 2050 and 2090, with a marginal net present value through 2090 of $10.4 million (additional to the baseline value of $346.2 million). Moderate versus severe climate change could avoid >50% of the additional oak pollen‐related asthma ED visits in 2090. Despite several key uncertainties and limitations, these results suggest that aeroallergens pose a substantial U.S. public health burden, that climate change could increase U.S. allergic disease incidence, and that mitigating climate change may have benefits from avoided pollen‐related health impacts.

Impacts of oak pollen on allergic asthma in the USA and potential effect of future climate change: a modelling analysis

BackgroundFuture climate change is expected to lengthen and intensify pollen seasons in the USA, potentially increasing incidence of allergic asthma. We examined the health consequences of present day oak pollen levels and climate-induced changes in oak pollen on asthma emergency department visits in the USA. MethodsWe estimated oak pollen season length for moderate (RCP4.5) and severe climate change scenarios (RCP8.5) from 2010 through to 2090 using five climate models and published relationships between temperature, precipitation, and pollen season length. We calculated asthma emergency department visit counts associated with 1994–2010 average oak pollen concentrations and with simulated future oak pollen season length changes using the Environmental Benefits Mapping and Analysis Program (BenMAP-CE), driven by epidemiologically derived concentration-response relationships. FindingsOak pollen was associated with an estimated 7400, 8800, and 5000 asthma emergency department visits in the northeast, southeast, and midwest USA, respectively, in 2010, with substantial economic damages. Most of these visits (14 600) occurred among children age younger than 18 years. Severe climate change could increase oak pollen season length and associated asthma emergency departments visits in all regions examined in 2030, 2050, 2070, and 2090, resulting in millions of dollars in health-care costs in these US regions through to 2090. Moderate versus severe climate change could mitigate much of the additional burden of oak pollen-related asthma emergency department visits. InterpretationAlthough these results were restricted to one pollen type and one health outcome, these results suggest that aeroallergens pose a substantial US public health burden, that climate change could increase US allergic disease incidence, and that mitigating climate change might have benefits from avoided pollen-related health effects. However, wide confidence intervals and several key methodological limitations constrain the strength of these conclusions. As more studies quantify the effects of climate on pollen and pollen on health, this methodology can be applied to additional pollen types and health outcomes. FundingUS Environmental Protection Agency.

CMAQ-pollen 모델을 이용한 참나무 꽃가루 확산 고해상도 수치모의 및 검증

The aim of this study is to evaluate the accuracy and variability of the oak pollen concentrations over the Seoul metropolitan region (SMR) simulated by the Community Multiscale Air Quality (CMAQ)-based pollen dispersion model, which is the CMAQ-pollen model integrated with the improved oak pollen emission model (PEM-oak). The PEM-oak model developed is based on hourly emission flux parameterization that includes the effects of plantspecific release, meteorological adjustment, and diurnal variations of oak pollen concentrations. A 33 day-run for oak pollen simulation was conducted by the CMAQ-pollen model with a 3 ㎞ spatial resolution for the SMR during the 2014 spring pollen season. Modeled concentrations were evaluated against the hourly measurements at three Burkard sampling sites. Temporal variations of oak concentrations were largely well represented by the model, but the quantitative difference between simulations and measurements was found to be significant in some periods. The model results also showed that large variations in oak pollen concentrations existed in time and space and high concentrations in the SMR were closely associated with the regional transport under strong wind condition. This study showed the effective application of the CMAQ-pollen modeling system to simulate oak pollen concentration in the SMR. Our results could be helpful in providing information on allergenic pollen exposure. Further efforts are needed to further understand the oak pollen release characteristics such as interannual variation of the oak pollen productivity and its spatio-temporal flowering timing.

Pollen viability in Quercus robur L.

The variability of viability (germination rate and the length of pollen tubes) of fresh pedunculate oak (Quercus robur L.) pollen grains was studied in vitro on a medium containing 15% sucrose. Spatial variability was studied by sampling fresh pollen grains from a total of thirteen trees at four different sites in the area of Belgrade (Kosutnjak, Banovo Brdo, Ada Ciganlija and Bojcin Forest) in a single year (2011). In order to assess temporal variability and determine the effects of climate change on a small time scale, we studied the viability of the pollen grains collected from one tree at the Banovo Brdo site in six different years (2004, 2005, 2006, 2007, 2011 and 2012). Interindividual variability was tested on the pollen grains sampled from eight trees at Ada Ciganlija in 2004. The percentage values of the pollen grain germination rate and the pollen tube length showed no statistically significant differences between the sites. However, the studied characteristics of the pollen grain viability (germination rate and pollen tube length) showed statistically significant differences in both temporal (between the pollen collection years) and interindividual variability. This type of research makes a valuable contribution to pedunculate oak breeding programs through the identification of trees with stable production and a good quality of pollen. Furthermore, it can be important in defining the patterns of spatial, temporal and individual variability of pollen grain viability under the influence of climate factors, which are showing compelling changing trends from year to year.

A methodical and taxonomic study of dispersed oak pollen (Fagaceae) from the Holocene of Rolla, Missouri, USA

Oak pollen has great potential to be used in reconstructing paleovegetation and paleoclimate. Pollen grains from Holocene sediments of Rolla, Missouri, USA were studied. The goal of this study was to evaluate the morphology of dispersed oak pollen using light and electron microscopy. Three types of oak pollen were recognized: Group 1, Group 2, and Group 3. They occurred in the sample in the following approximate percentage: 52, 32 and 16% respectively. Pollen of Group 1 corresponds to that of white oaks, pollen of Group 2 to that of red oaks. Pollen of Group 3 differs from oak pollen known for the studied region. While electron microscopy shows a good prospect for a detailed interpretation of dispersed oak pollen, many factors should be taken into account when assessing past vegetation: the paleo-forest density, location of sampling, apparent wind direction during pollination, and the “resolving ability” of pollen morphology for different oak species. The intensity of flowering and direction of the pollen transport can significantly influence the quantity of pollen of a particular species in the spectrum. The possibility of medium or long-distance transport of a small quantity of oak pollen from other regions should also be considered in the interpretations of fossil spectra.

Modeling the distribution and increase of oak pollen over the Seoul metropolitan region

Introduction: Numerical modeling techniques could enhance our understanding about exposure assessment for allergic pollen. This study aims to understand the spatiotemporal distribution and increase of oak pollen associated with transport and dispersion over the Seoul metropolitan region (SMR) in Korea using Community Multi-scale Air Quality (CMAQ) model. Methods: A 10 day-run for oak pollen simulation was conducted during high oak pollen periods in 2014 using CMAQ pollen modeling system. This system consists of Weather Research and Forecast (WRF) model and CMAQ linked with Oak Pollen Emission Model (OPEM). Oak pollen inventories were calculated by OPEM which uses as inputs the meteorological parameters (temperature, wind speed, relative humidity, and vertical turbulence velocity) produced by WRF model, measured pollen counts, and the oak tree coverage data from Forest Geographic Information System. Results: The simulated temporal variation of the oak pollen concentrations reasonably followed the measured concentration from the Burkard sampling stations in the SMR. The spatial distribution of pollen was closely associated with some meteorological conditions allowing to transport and accumulation. In particular, in urban area early in the morning on 19 April, high concentration of oak pollen was related with wind flow and lower-atmospheric structure in the planetary boundary layer. Conclusions: Our results revealed that the spatiotemporal distribution and increase of oak pollen were significantly associated with the meteorological processes and this modeling approach could be assisted to estimate population exposure to allergic pollen.

Record of vegetation, climate change, human impact and retting of hemp in Garhwal Himalaya (India) during the past 4600 years

This study is focused on a 3.55-m-long sediment core retrieved from Badanital (i.e. the BT core) in 2008. Badanital (30°29′50″N, 78°55′26″E, 2083 m a.s.l.) is a small lake located in the upper catchment area of the Ganges in Garhwal Himalaya, northern India. The lake and the regional broad-leaved semi-evergreen forests are under the influence of the Indian Summer Monsoon (ISM) and westerly associated cyclones. Palynological investigation of the BT core revealed past vegetation changes reflecting both climate and human impact during the last 4600 years. Maximum spread of oaks occurred during c. AD 550–1100 and c. AD 1400–1630, that is, the intervals which partly overlap with the ‘Medieval Warm Period’ and the ‘Little Ice Age’, respectively. Three intervals of decreased oak pollen percentages are attributed to (1) continuously drier and cooler climatic conditions and fire activity ( c. 2600–500 BC), (2) severe reduction in oak forests followed by secondary succession of alder woods ( c. AD 1150–1270) and (3) pre-modern settlement activities since the British imperial occupation (after c. AD 1700). We argue that the high percentages (i.e. up to 28%) of Humulus/ Cannabis type and Cannabis type pollen point to intense local retting of hemp c. 500 BC–AD 1050. Based on our age model, Cannabis fibre production at Badanital is contemporaneous with archaeological records of ancient hemp products from different parts of Eurasia suggesting possible linkages to early trade and knowledge exchange routes connecting India and the Himalaya with Central and East Asia and possibly Europe.

Effect of nitrogen dioxide and sulfur dioxide on viability and morphology of oak pollen.

Nitrogen dioxide (NO2) and sulfur dioxide (SO2) generated by excessive coal combustion and motor vehicle emissions are major air pollutants in the large cities of China. The objective of our study was to determine the effects of the exposure of oak pollens (Quercusmongolica) to several concentrations of NO2 or SO2. Pollen grains were exposed to 0.5 ppm to 5.0 ppm NO2 or SO2 for 4 hours and assessed for morphological damage by field emission scanning electron microscopy and for viability using the trypan blue stain. Morphological changes in pollen grains were also examined after contact with acid solutions at pH 4.0 to pH 7.0. Exposure to NO2 or SO2 significantly damaged pollen grains at all concentrations investigated, compared to exposure to air; with exposure to concentrations of 0.5 ppm to 2 ppm resulting in fissures or complete breaks in the exine and a concentration of 5 ppm resulting in complete breakdown and release of pollen cytoplasmic granules. Significantly greater amounts of pollen grain were damaged after exposure to SO2 (15.5-20.4%) than after exposure to NO2 (7.1-14.7%). Similarly, exposure to NO2 or SO2 significantly decreased the viability of pollen grains, compared with exposure to air; with SO2 being slightly more detrimental than NO2. Exposure to acid solutions also induced pollen damage, which appeared to be pH-dependent (from 24.6% at pH 6.0 to 55.8% at pH 4.0; compared to 3.8% at pH 7.0). Short-term exposure of oak pollen to high concentrations of SO2 or NO2 significantly increases their fragility and disruption, leading to subsequent release of pollen cytoplasmic granules into the atmosphere. These results suggest that heightened air pollution during the oak pollen season may possibly increase the incidence of allergic airway disease in sensitized individuals by facilitating the bioavailability of airborne pollen allergens.

한반도 참나무 꽃가루 확산예측모델 개발

한반도 참나무 꽃가루 확산예측모델 개발

Cluster analysis of intradiurnal holm oak pollen cycles at peri-urban and rural sampling sites in southwestern Spain.

The impact of regional and local weather and of local topography on intradiurnal variations in airborne pollen levels was assessed by analysing bi-hourly holm oak (Quercus ilex subsp. ballota (Desf.) Samp.) pollen counts at two sampling stations located 40 km apart, in southwestern Spain (Cordoba city and El Cabril nature reserve) over the period 2010-2011. Pollen grains were captured using Hirst-type volumetric spore traps. Analysis of regional weather conditions was based on the computation of backward trajectories using the HYSPLIT model. Sampling days were selected on the basis of phenological data; rainy days were eliminated, as were days lying outside a given range of percentiles (P95-P5). Analysis of cycles for the study period, as a whole, revealed differences between sampling sites, with peak bi-hourly pollen counts at night in Cordoba and at midday in El Cabril. Differences were also noted in the influence of surface weather conditions (temperature, relative humidity and wind). Cluster analysis of diurnal holm oak pollen cycles revealed the existence of five clusters at each sampling site. Analysis of backward trajectories highlighted specific regional air-flow patterns associated with each site. Findings indicated the contribution of both nearby and distant pollen sources to diurnal cycles. The combined use of cluster analysis and meteorological analysis proved highly suitable for charting the impact of local weather conditions on airborne pollen-count patterns. This method, and the specific tools used here, could be used not only to study diurnal variations in counts for other pollen types and in other biogeographical settings, but also in a number of other research fields involving airborne particle transport modelling, e.g. radionuclide transport in emergency preparedness exercises.

약용버섯을 이용한 도토리화분의 세포 발아 및 항산화 활성

도토리화분의 총 폴리페놀함량은 화분배지에 뽕나무버섯(Armillaria mellea) 배양한 발아액에서 가장 높았으며, 표고(Lentinula edodes) 발아액에서 가장 낮았다. 뽕나무버섯을 배양한 발아액 중에서 동결건조 화분의 발아액이 정제화분과 저온초미분쇄화분의 발아액보다 총 폴리페놀함량이 많았다. 또한 동결건조 화분의 뽕나무버섯 발아액은 물추출액보다 총 폴리페놀함량이 1.4배 높았다. 도토리화분의 DPPH radical 소거능은 뽕나무버섯 발아액에서 가장 높았으며, 표고 발아액에서 가장 낮았다. 동결건조 화분의 뽕나무버섯 발아액은 DPPH radical 소거능이 물추출보다 2~4배 높았다. 수집된 꿀벌화분은 알갱이 형태이며, 꿀벌의 분비물을 제거한 순수 화분은 분말형태로 크기는 0.1~0.003 mm 정도이다. 화분의 전자현미경 구조는 도토리화분은 단립이며 모양은 장구형(prolate)이고 극면상은 난형이다. 발아구는 3구형이며 비교적 짧고 곧은 주름이 있다. 표면은 과립상(verrucate) 또는 미립상(scabrate)으로 불규칙한 돌기가 있다. 저온초미분쇄한 화분은 세포벽이 파쇄 또는 절단되었으며, 동결건조한 화분에서는 세포벽이 파열되어 세포질이 나출되는 양상을 보였다. 표고를 접종한 도토리 화분의 세포 발아 형태는 공구(pore) 주변에 외피가 없는 다량의 발아세포가 형성되었으며, 뽕나무버섯을 접종한 화분배지에서의 세포 발아 형태는 화분에서 균사속과 유사한 발아관이 형성되고 그 끝에 발아세포가 형성되었다. In this study, we measured antioxidant activity as DPPH radical scavenging and the total polyphenol content of pulverized and lyophilized oak pollens inoculated with fungi to confirm the husk removal effect. The total polyphenol content of oak pollen was highest in lyophilized pollen medium inoculated with Armillaria mellea, and was lowest in pollen inoculated with Lentinula edodes. Total polyphenol content of the lyophilized pollen was higher than that of the refined pollen and the pulverized pollen in oak pollen germinated with A. mellea. The total polyphenol content of the lyophilized oak pollen germinated with A. mellea was 1.4-fold higher than that extracted with water. Measurement of antioxidant activity using the DPPH (2, 2 diphenyl-1-picrylhydrazyl) free radical scavenging method showed that the lyophilized oak pollen germinated with A. mellea had the highest and that germinated with L. edodes was lowest in antioxidant activities. The lyophilized oak pollen germinated with A. mellea was 2 to 4 times higher than that extracted with water in the antioxidant activity of DPPH free radical scavenging. Many germinated cells were formed around pore of acorn pollen inoculated with L. edodes, while those were formed at the end of hyphae derived from oak pollen inoculated with A. mellea.