Pollen calling

A bee, packed with pollen, prepares to buzz into a blooming sunflower in a field in Frankfurt (Oder), Germany. Pollinators are animals that move pollen from the male anther of a flower to the female stigma of a flower, helping to fertilize it. The most widely recognized pollinators are the various species of bees, although many other insects and animals, including some bats and birds, pollinate.

Little islands of pollen cover a car roof in Stuttgart, Germany. The pollen count for the coniferous spruce tree has been very high recently. "This year, there were ideal flight conditions," said Christina Endler of the German Weather Service. "It was dry, there was a lot of sunshine and light wind." Adding to the bounty is the fact that a cold winter was followed by an unusually warm spring.

Every walnut tree has both male and female parts, meaning they are monoecious, to use the biological term. Not dependent on pollinators, the pollen is largely spread by wind, from the male to the female parts. All walnut varieties are self-fertile, meaning the pollen can, in theory, travel from the male to the female parts of the same tree. Cross pollination has a higher chance of success though.

What looks like yellow fog here is in fact pollen from coniferous forests being blown around the Niedersonthofener Lake, in Bavaria, Germany. As a general rule, meteorologists say that the warmer the winter is, the sooner the pollen season begins. Also, according to a study by allergist Leonard Bielory, pollen counts could double by the year 2040 due to climate change.

Chestnut trees (pictured here) produce both welcome shade in summer and the well-known nuts, most commonly associated with roasting on open fires in the depths of winter. These deciduous trees cannot self-pollinate. They rely on wind and insects to move the pollen from one tree to the next.

The spread of pollen in the springtime can be quite a sight. The expression "the forest is blooming" refers to the phenomenon of the pollen of conifers, usually spruce trees (those typically found in many German forests), filling the air to the extent that visibility is affected. Your best chance of experiencing this phenomenon is when the weather is especially dry.

Think you get a lot done in a day? It is commonly estimated that a single honey bee can land on 5,000 flowers in one day. Pollen sticks to them as they do so and it is then brought to other flowers, allowing fertilization to occur. Are they nature's greatest matchmakers? Maybe, but if they are it is inadvertent; pollinators are usually looking for something for themselves, such as nectar.

When rough winds do shake the darling buds - and pollen - of May, hayfever sufferers know all about it. Allergic rhinitis is the medical name for hayfever, and it occurs when a person's immune system overreacts to the presence of pollen and attacks it mistakenly, as if it were a parasite. As a result, the person sneezes, in a misguided attempt to "expel" something that is actually quite harmless.

German observers will have noticed masses of yellow pollen accumulating in recent days and weeks, with much of it coming from pine and spruce trees. The high volume has been even greater as a result of the particularly dry spell of recent weather. In this picture, taken in North Rhine-Westphalia, western Germany, pollen residue is seen on the street.

We all like to see a nice blooming corn field like the one pictured here, but we ought to be prepared for increasing amounts of pollen as the planet continues to heat up. According to the aforementioned Bielory study, in the year 2000, pollen counts (measurement of the number of grains of pollen in a cubic meter of air) averaged 8,455. By 2040, these counts are anticipated to reach 21,735.