scholarly journals Impact of pollen on throughfall biochemistry in European temperate and boreal forests

2020 ◽  
Author(s):  
Arne Verstraeten ◽  
Elena Gottardini ◽  
Nicolas Bruffaerts ◽  
Fabiana Cristofolini ◽  
Elena Vanguelova ◽  
...  
Keyword(s):  
Airborne Pollen ◽  
Inorganic Nitrogen ◽  
Pollen Dispersal ◽  
Negative Relationship ◽  
Silver Birch ◽  
Pollution Effects ◽  
Dissolution Experiment ◽  
N Transformations ◽  
Pollen Concentrations

<p>Pollen is known to affect forest throughfall biochemistry, but underlying mechanisms are not fully understood. We used generalized additive mixed modelling to study the relationship between long-term series of measured throughfall fluxes in spring (April–June) at forest plots and corresponding airborne pollen concentrations (Seasonal Pollen Integral, SPIn) from nearby aerobiological monitoring stations. The forest plots were part of the intensive long term monitoring (Level II) network of the UNECE International Co-operative Programme on Assessment and Monitoring of Air Pollution Effects on Forests (ICP Forests) with dominant tree genera <em>Fagus</em>, <em>Quercus</em>, <em>Pinus</em> and <em>Picea</em>, and were distributed all across Europe. We also conducted a 7-day laboratory dissolution experiment with bud scales and flower stalks of European beech (<em>Fagus sylvatica</em> L.), pollen of beech, common oak (<em>Quercus robur</em> L.), silver birch (<em>Betula pendula</em> L.), Scots pine (<em>Pinus sylvestris</em> L.), Corsican pine (<em>Pinus nigra</em> Arnold ssp. <em>laricio</em> (Poiret) Maire), Norway spruce (<em>Picea abies</em> (L.) Karst.) and sterilized pollen of silver birch in a nitrate (NO<sub>3</sub><sup>-</sup>-N) solution (11.3 mg N L<sup>-1</sup>). Throughfall fluxes of potassium (K<sup>+</sup>), ammonium (NH<sub>4</sub><sup>+</sup>-N), dissolved organic carbon (DOC) and dissolved organic nitrogen (DON) showed a positive relationship with SPIn whereas NO<sub>3</sub><sup>-</sup>-N fluxes showed a negative relationship with SPIn. In years with massive seed production of beech and oak SPIn and throughfall fluxes of K<sup>+</sup> and DOC were higher, but fluxes of NO<sub>3</sub><sup>-</sup>-N were lower. The experiment broadly confirmed the findings based on field data. Within two hours, pollen released large quantities of K<sup>+</sup>, phosphate, DOC and DON, and lesser amounts of sulphate, sodium and calcium. After 24-48 hours, NO<sub>3</sub><sup>-</sup>-N started to disappear, predominantly in the treatments with broadleaved pollen, while concentrations of nitrite and NH<sub>4</sub><sup>+</sup>-N increased. At the end of the experiment, the inorganic nitrogen (DIN) was reduced, presumably because it was lost as gaseous nitric oxide (NO). There was no difference for sterilized pollen, indicating that the involvement of microbial activity was limited in above N transformations. Our results show that pollen dispersal might be an overlooked factor in forest nutrient cycling and might induce complex canopy N transformations, although the net-impact on N throughfall fluxes is rather low.</p>

scholarly journals Changes in the concentration of pollen over an 11-year period in a Polish urban environment

2016 ◽  
Vol 69 (4) ◽  
Author(s):  
Barbara Majkowska-Wojciechowska ◽  
Zofia Balwierz ◽  
Marek L. Kowalski
Keyword(s):  
Airborne Pollen ◽  
Allergenic Pollen ◽  
Reproductive Systems ◽  
Atmospheric Air ◽  
Qualitative And Quantitative ◽  
Pollen Concentrations ◽  
Poaceae Pollen ◽  
Dynamic Concentration ◽  
The City

Recent studies suggest that climate change can influence plant reproductive systems and have an impact on the increase in allergenic pollen in atmospheric air; highly allergenic pollen may intensify the allergic response in people. The aim of our study was to evaluate the seasonal dynamic concentration of the most allergenic pollen taxa, i.e., the following trees: <em>Alnus</em>, <em>Corylus</em>, <em>Betula</em>, and herbaceous plants: grasses (Poaceae), <em>Artemisia</em>, and <em>Ambrosia</em>, in the long-term period of 2003–2013 in the city of Lodz, Poland. Weekly airborne pollen concentrations were evaluated with a volumetric Lansoni pollen trap. The beginning and the end of the season were calculated by the 98% method. The birch (<em>Betula</em>) pollen was at the highest level and accounted for 79%, followed by alder (<em>Alnus</em>) – 19%, and hazel (<em>Corylus</em>) – 2%. Among the herbaceous taxa, grasses (Poaceae) pollen dominated – 79%, followed by mugwort (<em>Artemisia</em>) – 18%, and ragweed (<em>Ambrosia</em>) – 3%. Our findings indicate a lack of qualitative and quantitative change in the pollen produced over the 11-year period.

Risk Attitude and Corporate Investment under Output Market Uncertainty: Evidence from The Mekong River Delta, Vietnam

2016 ◽  
pp. 59-70
Author(s):  
Ninh Le Khuong ◽  
Nghiem Le Tan ◽  
Tho Huynh Huu
Keyword(s):  
Negative Relationship ◽  
Risk Attitude ◽  
Business Strategies ◽  
Risk Averse ◽  
Market Uncertainty ◽  
Firm Investment ◽  
Output Market ◽  
The Impact ◽  
The Relationship

This paper aims to detect the impact of firm managers’ risk attitude on the relationship between the degree of output market uncertainty and firm investment. The findings show that there is a negative relationship between these two aspects for risk-averse managers while there is a positive relationship for risk-loving ones, since they have different utility functions. Based on the findings, this paper proposes recommendations for firm managers to take into account when making investment decisions and long-term business strategies as well.

scholarly journals Higher Temperatures Decrease Fruit Size in Strawberry Growing in the Subtropics

Horticulturae ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 34
Author(s):  
Christopher Menzel
Keyword(s):  
Fruit Size ◽  
Negative Relationship ◽  
Titratable Acidity ◽  
Fruit Weight ◽  
Soluble Solids ◽  
Marketable Yield ◽  
Significant Relationships ◽  
Small Fruit ◽  
Solids Content

Five strawberry (Fragaria × ananassa Duch.) cultivars were grown in Queensland, Australia to determine whether higher temperatures affect production. Transplants were planted on 29 April and data collected on growth, marketable yield, fruit weight and the incidence of small fruit less than 12 g until 28 October. Additional data were collected on fruit soluble solids content (SSC) and titratable acidity (TA) from 16 September to 28 October. Minimum temperatures were 2 °C to 4 °C higher than the long-term averages from 1965 to 1990. Changes in marketable yield followed a dose-logistic pattern (p < 0.001, R2s = 0.99). There was a strong negative relationship between fruit weight (marketable) and the average daily mean temperature in the four or seven weeks before harvest from 29 July to 28 October (p < 0.001, R2s = 0.90). There were no significant relationships between SSC and TA, and temperatures in the eight days before harvest from 16 September to 28 October (p > 0.05). The plants continued to produce a marketable crop towards the end of the season, but the fruit were small and more expensive to harvest. Higher temperatures in the future are likely to affect the economics of strawberry production in subtropical locations.

scholarly journals Nutrient retention behind a tropical mega-dam: a case study of the Sardar Sarovar Dam, India

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Harish Gupta ◽  
S. Kiran Kumar Reddy ◽  
Mounika Chiluka ◽  
Vamshikrishna Gandla
Keyword(s):  
Arabian Sea ◽  
Inorganic Nitrogen ◽  
Nutrient Retention ◽  
Significant Loss ◽  
N Removal ◽  
Narmada River ◽  
Sardar Sarovar ◽  
The Impact

AbstractIn this study, we demonstrate the impact of the construction of a mega-dam on the nutrient export regime of a large tropical river into the Arabian Sea. Long-term (11 years) fortnight nutrient parameters, upstream and downstream to Sardar Sarovar (SS) Dam, were examined to determine the periodical change in nutrient fluxes from the Narmada River, India. During this 11-year period, the average discharge of the Narmada River upstream to Rajghat (35.3 km3 year−1) was higher than that of downstream at Garudeshwar (33.9 km3 year−1). However, during the same period, the suspended sediment load was reduced by 21 million tons (MT) from 37.9 MT at Rajghat to 16.7 MT at Garudeshwar. Similarly, mean concentrations of dissolved silica (DSi) reduced from 470 (upstream) to 214 µM (downstream), dissolved inorganic phosphate (DIP) from 0.84 to 0.38 µM, and dissolved inorganic nitrogen (DIN) from 43 to 1.5 µM. It means that about 54%, 55%, and 96% flux of DSi, DIP, and DIN retained behind the dam, respectively. The estimated denitrification rate (80,000 kg N km−2 year−1) for the reservoir is significantly higher than N removal by lentic systems, globally. We hypothesize that processes such as biological uptake and denitrification under anoxic conditions could be a key reason for the significant loss of nutrients, particularly of DIN. Finally, we anticipated that a decline in DIN fluxes (by 1.13 × 109 mol year−1) from the Narmada River to the Arabian Sea might reduce the atmospheric CO2 fixation by 7.46 × 109 mol year−1.

Aspiring to Do All Things Through Him Who Strengthens? Quixotic Hope, Religiosity, and Mental Health in Emerging Adulthood

2021 ◽  
pp. 215686932110085
Author(s):  
Laura Upenieks
Keyword(s):  
Mental Health ◽  
Negative Relationship ◽  
Well Being ◽  
Educational Expectations ◽  
Religious Practice ◽  
The United States ◽  
Religious Attendance ◽  
National Study ◽  
Health Consequences

Beliefs about the probability of educational success tend to be very optimistic in the United States. However, scholars are beginning to uncover mental health consequences associated with quixotic hope—the unrealistic outstripping of expectation by aspiration. Using longitudinal data from Waves 1 and 3 of the National Study of Youth and Religion, this study asks, (1) does religiosity promote or diminish the likelihood of quixotic hope? and (2) does religious attendance and closeness to God mitigate long-term mental health consequences of quixotic hope? Results show that weekly religious attendance had a modest negative relationship with the likelihood of experiencing quixotic hope, while increasing religious attendance over time attenuated the negative mental health consequences of quixotic hope on increases in depression. Closeness to God neither predicted quixotic hope nor played a moderating role for depression. As educational expectations rise, regular religious practice may help protect the emotional well-being of youth.

scholarly journals Trends and threshold exceedances analysis of airborne pollen concentrations in Metropolitan Santiago Chile

PLoS ONE ◽  
2015 ◽  
Vol 10 (5) ◽  
pp. e0123077 ◽  
Author(s):  
Richard Toro A. ◽  
Alicia Córdova J. ◽  
Mauricio Canales ◽  
Raul G. E. Morales S. ◽  
Pedro Mardones P. ◽  
...  
Keyword(s):  
Airborne Pollen ◽  
Pollen Concentrations ◽  
Threshold Exceedances

scholarly journals Neural networks for increased accuracy of allergenic pollen monitoring

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Marcel Polling ◽  
Chen Li ◽  
Lu Cao ◽  
Fons Verbeek ◽  
Letty A. de Weger ◽  
...  
Keyword(s):  
Neural Networks ◽  
Airborne Pollen ◽  
Pollen Grains ◽  
Allergenic Pollen ◽  
Herbarium Specimens ◽  
Pollen Monitoring ◽  
Pollen Concentrations ◽  
Source Of Information ◽  
Urticaceae Pollen

AbstractMonitoring of airborne pollen concentrations provides an important source of information for the globally increasing number of hay fever patients. Airborne pollen is traditionally counted under the microscope, but with the latest developments in image recognition methods, automating this process has become feasible. A challenge that persists, however, is that many pollen grains cannot be distinguished beyond the genus or family level using a microscope. Here, we assess the use of Convolutional Neural Networks (CNNs) to increase taxonomic accuracy for airborne pollen. As a case study we use the nettle family (Urticaceae), which contains two main genera (Urtica and Parietaria) common in European landscapes which pollen cannot be separated by trained specialists. While pollen from Urtica species has very low allergenic relevance, pollen from several species of Parietaria is severely allergenic. We collect pollen from both fresh as well as from herbarium specimens and use these without the often used acetolysis step to train the CNN model. The models show that unacetolyzed Urticaceae pollen grains can be distinguished with > 98% accuracy. We then apply our model on before unseen Urticaceae pollen collected from aerobiological samples and show that the genera can be confidently distinguished, despite the more challenging input images that are often overlain by debris. Our method can also be applied to other pollen families in the future and will thus help to make allergenic pollen monitoring more specific.

Spatial interpolation of current airborne pollen concentrations where no monitoring exists

2019 ◽  
Vol 199 ◽  
pp. 435-442 ◽  
Author(s):  
Jose Oteros ◽  
Karl-Christian Bergmann ◽  
Annette Menzel ◽  
Athanasios Damialis ◽  
Claudia Traidl-Hoffmann ◽  
...  
Keyword(s):  
Spatial Interpolation ◽  
Airborne Pollen ◽  
Pollen Concentrations

scholarly journals Interaction among Controlling Factors on Riverine DIN Export in Small Mountainous Rivers of Taiwan: Inseparable Human-Landscape System

Water ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2981
Author(s):  
Wen-Shiuan Lee ◽  
Jr-Chuan Huang ◽  
Chung-Te Chang ◽  
Shih-Chien Chan ◽  
Ying-San Liou ◽  
...  
Keyword(s):  
Inorganic Nitrogen ◽  
Seasonal Pattern ◽  
Water Quality Management ◽  
Negative Relationship ◽  
Dry Season ◽  
Mitigation Strategies ◽  
Minor Effect ◽  
Dominant Form ◽  
Wide Range ◽  
Human Landscape

Increasing anthropogenic nitrogen (N) emission via different pathways has shown prominent impact on aquatic ecosystems for decades, but the effects of interaction among climate-, landscape- and human-associated variables on riverine DIN (dissolved inorganic nitrogen, mainly NO3− and NH4+) export are unclear. In this study, the data of 43 watersheds with a wide range of climate-, landscape- and human-associated gradients across Taiwan were evaluated with partial redundancy analysis (pRDA) to examine their interactive controls on riverine DIN export. Results show that the annual riverine DIN export in Taiwan is approximately 3100 kg-N km−2 yr−1, spanning from 230 kg-N km−2 yr−1 in less disturbed watersheds (eastern and central Taiwan) to 10,000 kg-N km−2 yr−1 in watersheds with intensive human intervention (southwestern and northern Taiwan). NO3− is generally the single dominant form of DIN, while NH4+ renders significance in disturbed watersheds. Nearly all environmental variables display a positive correlation with DIN export, except for landscape setting variables (e.g., slope, area, channel length), which show a negative relationship. In terms of seasonal pattern, climate and human-landscape variables are related to NO3− export independently in the wet season, yet in the dry season climate-human variables jointly dominate NO3− export. Meanwhile, human-landscape (LH) variables (λ1 of LH > 0.60) control NH4+ exports in both seasons, and human-associated (H) variables (λ1 of H = 0.13) have a minor effect on NH4+ exports in dry season. Precisely, the contribution of controlling variables on DIN export vary with species and seasons, indicating water quality management could be time-dependent, which should be taken into consideration for designing mitigation strategies.

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