The chestnut tree: from a staple food to an ecological disaster

Stars, a regional newspaper covering the Madona area in Latvia, has published an article on the chestnut tree, which for thousands of years has been an important food source, timber supply and cultural symbol in the Northern Hemisphere. The full text is available only to subscribers, but the open excerpt outlines the tree's history.

Origins and spread

Genetic studies indicate that the chestnut genus emerged 10–15 million years ago, before the Ice Age, in Asia Minor and the Mediterranean region. From there the trees spread through Europe to North America. In Japan, chestnuts were cultivated even before rice farming began.

In Latvian, two different plant families are called by similar names. Edible chestnuts were eaten as food as early as the Middle Stone Age, but a culture of growing them developed only from the 6th century BC. The oldest written evidence dates from 350 BC. The ancient Romans and Alexander the Great planted chestnuts across Europe during their military campaigns, and the Romans spread the tree to regions where grain would not grow.

Diet and decline

In the mountainous Mediterranean, chestnuts were the main staple for centuries. Dried nuts were ground into flour rich in starch and sugars. A large tree yielded up to 200 kg of fruit a year, and in the Middle Ages this "poor man's bread tree" was actively grown in monastery gardens. Its place in everyday diets shrank in the 19th century, as potatoes spread and industrialisation began.

In North America, the American chestnut once made up a quarter of the hardwood trees in eastern forests. A fungal disease brought from Asia in 1904 destroyed almost 4 billion American chestnut trees in fewer than 50 years. It is regarded as one of the largest ecological catastrophes.