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Nature Notes
June 21st is the summer solstice; the approximate longest day, then the shortest night. After this date, days get shorter and the nights longer. However, this is a gradual process, and July and August can often be warmer than June. The remarkable thing about the solstice is that it is word wide. Wherever you are in the northern hemisphere, the sun will be at its highest at that time. Of course, above the Arctic Circle, this will be one of many 24 hour daylight days. In the Antarctic, it will be one of many 24 hour dark days. Even so, the male emperor penguins will be incubating their single eggs in freezing temperatures.
On the equator, the seasons are much less well defined, with day-lengths not changing much throughout the year. The seasons there are usually defined as wet or dry. It generally follows that the richest biodiversity occurs where the temperatures are highest; however, it is also limited by amounts of life-giving water. Tropical wetlands may be the most bio-diverse habitats of them all, with rain-forests in flood-plains being the best of those.
Our own flood-plains are also very rich in life. If you get a chance, take a wander in the Uck flood-plain behind the Co-op Supermarket. This is Hempstead Meadows Local Nature Reserve. This time of the year you will see a myriad of dragonflies, butterflies and other insects. Also there are wild flowers galore, especially in the permanently wet area past the first field. Yellow flag irises are looking great at present, and the hemlock water-dropwort is festooning the marshes with its white umbels. The vivid blue meadow cranes-bill adorns the wayside in the first field, and the purple loostrife will soon be in bloom. Despite our best efforts, you will also see the flowers of the Himalayan balsam, an alien invader from the mountains of the same name. Like most alien invaders, it has an element of beauty that masks a sinister objective – to dominate its new found home! However, bees like it, and it makes excellent honey. Unchecked it will aim reduce the biodiversity of the reserve to one species – its own. This is a real threat to the reserve.
July is usually the warmest month in England. Plants will be taking advantage of this and setting their seeds and putting on leaves. The forests will be dark beneath, but among the foliage the animals born and hatched in the spring will be eating their fill - a time of plenty for most.
Dr. Martyn Stenning
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Nature Notes 
