Dispersal of pollen and invertebrates by wind in contrasting Arctic habitats of Svalbard

Although Svalbard archipelago is considered as a natural laboratory for the environmental studies in the High Arctic, the knowledge on the transport and diversity of bioaerosols (aeroplankton) in the atmosphere is poorly recognized. To improve our knowledge about the aeroplankton over the Svalbard, we conducted a short-term study in the central part of the archipelago with a special focus on two important, but understudied in this region, airborne components: pollen grains and invertebrates. Aerobiological traps, three impact-type samplers and 12 pitfall-type water traps, were operated for a week of July 2022 at three sites located near Longyearbyen, the largest settlement of Svalbard. These sites, that is, Platåfjellet, Longyearbreen Glacier, and glacier valley, varied in the local sources of biological material and altitude. In total, 11 pollen taxa were isolated from pollen impactors. Most of them (68%) belonged to non-native plants, for example, Alnus sp., Betula sp., Picea abies, or Pinus sylvestris-type pollen. In pitfall-type water traps, we found invertebrates representing Acari (Prostigmata, Endeostigmata and Oribatida), Collembola (Agrenia bidenticulata), Tardigrada (Eutardigrada) and Rotifera (Bdelloidea). The most taxa-rich site, both for pollen and invertebrates, was Platåfjellet, characterized by open landscape dominated by small cryptogams, mainly lichens and mosses, and sparse patches of vascular plants. Even though our sampling was short-term, we found diverse taxa belonged to native and alien species, indicating that both local and long-range transport shape aeroplankton composition and seeding of Arctic habitats. Long-term aerobiological monitoring in diverse ecosystems of Svalbard is needed to understand spatio-temporal influence of aeroplankton on ecosystems

Changes to Airborne Pollen Counts across Europe

A progressive global increase in the burden of allergic diseases has affected the industrialized world over the last half century and has been reported in the literature. The clinical evidence reveals a general increase in both incidence and prevalence of respiratory diseases, such as allergic rhinitis (common hay fever) and asthma. Such phenomena may be related not only to air pollution and changes in lifestyle, but also to an actual increase in airborne quantities of allergenic pollen. Experimental enhancements of carbon dioxide (CO2) have demonstrated changes in pollen amount and allergenicity, but this has rarely been shown in the wider environment. The present analysis of a continental-scale pollen data set reveals an increasing trend in the yearly amount of airborne pollen for many taxa in Europe, which is more pronounced in urban than semi-rural/rural areas. Climate change may contribute to these changes, however increased temperatures do not appear to be a major influencing factor. Instead, we suggest the anthropogenic rise of atmospheric CO2 levels may be influentia

API trends against temperature trends by species.

<p>Proportional annual change of yearly pollen sums was plotted against local temperature trends for 23 pollen taxa. Temperature trends were calculated for each location for the mean temperature of two seasons, January to April (associated with the flowering of <i>Alnus</i>, <i>Betula</i>, <i>Carpinus</i>, <i>Corylus</i>, Cupressaceae, <i>Fagus</i>, <i>Fraxinus</i>, <i>Olea</i>, Pinaceae, <i>Platanus</i>, <i>Populus</i>, <i>Quercus</i>, <i>Salix</i>, and <i>Ulmus</i>) or April to August (related to <i>Ambrosia</i>, <i>Artemisia</i>, <i>Castanea</i>, Chenopodiaceae, <i>Plantago</i>, Poaceae, <i>Rumex</i>, <i>Tilia</i>, and <i>Urtica</i>), over the years 1977–2009. A regression line has been superimposed for <i>Betula</i> and <i>Carpinus</i>, the only statistically significant relationships.</p

Maximum duration of pollen series by location.

<p>The local longest monitored period is shown as a red bar for each of the 97 locations considered. Missing years, occurring in few cases, have been omitted for clarity.</p

API trends by environment type.

<p>Boxplots show the proportional annual change of yearly pollen sums for different environments. Mann-Whitney tests show a significant increase (median different from zero, ) of airborne pollen in urban environments. The notches are calculated as and the height of each boxplot is related to sample size. On the right, the percentages of significant trends are indicated for each type of environment (of which the percentages of positive trends are given in parentheses).</p

Mean API against mean local temperature.

<p>Log-scaled mean annual sum of airborne pollen was plotted against local mean temperature for 23 pollen taxa. Mean temperatures were calculated for two periods, January to April (associated with the flowering of <i>Alnus</i>, <i>Betula</i>, <i>Carpinus</i>, <i>Corylus</i>, Cupressaceae, <i>Fagus</i>, <i>Fraxinus</i>, <i>Olea</i>, Pinaceae, <i>Platanus</i>, <i>Populus</i>, <i>Quercus</i>, <i>Salix</i>, and <i>Ulmus</i>) or April to August (related to <i>Ambrosia</i>, <i>Artemisia</i>, <i>Castanea</i>, Chenopodiaceae, <i>Plantago</i>, Poaceae, <i>Rumex</i>, <i>Tilia</i>, and <i>Urtica</i>), over the period 1977–2009. Only significant regression lines are shown.</p

Trends of annual pollen index (API) by species.

<p>Boxplots show the proportional annual change of yearly pollen sums for the 23 pollen taxa analyzed (reasons for selection given in the main text). Medians are significantly different from zero (Mann-Whitney test, * : , ** : , *** : , n.s.: ) for 11 taxa. On the right, the percentages of significant trends are indicated for each taxon (of which the percentages of positive trends are given in parentheses). The height of the boxplot is related to sample size, taxa are arranged in decreasing order of their medians.</p

Locations of pollen sites.

<p>Each station has been indicated by a red circle. Symbol sizes are proportional to the temporal length of the local longest pollen record.</p