Did you know that elm trees were nearly wiped out by a fungal disease carried by beetles?
Before elm was disseminated by beetles carrying a microfungi, it was the second most important broad leaf timber in Britain to oak. Like oak, it was of great landscape importance and formed an important component of our native woodland, supporting a wide range of fauna and flora.
Elm hosts around 80 species of invertebrates such as the rare White-letter Hairstreak (Satyrium w-album) and in spring, its early pollen is sought after by many insects including honey bees.
Elms are also a very important food source for songbirds, game birds and squirrels as their seeds develop long before many other seeds are available.
Over the past century there have been two pandemics of Dutch Elm Disease (DEM) caused by two separate but related species of Asian microfungi, Ophiostoma ulmi and O. novo-ulmi. The non-native microfungi are dispersed by bark beetles of the genera Scolytus and Hylurgopinus. These beetles are no larger than 6mm in length and are definitely small pests causing big problems!
The first pandemic began in early the 1900’s and declined then onward until the 1930’s across Europe and North America, killing 30-40% of elms.
The second pandemic spread across the same areas and by 1990 most mature elms of European and North American origin died. In Britain alone, it is estimated that around 30 million mature elms died.
The microfungi causes tree death by blocking the xylem. The xylem is the route where water is transported from the roots to the stems and leaves of the tree. Signs of DED include wilting, yellowing and browning of leaves and young shoots.
Miraculously, a few mature specimens narrowly escaping the epidemic have been identified! With the help of a few enthusiasts a new generation of elite elm seedlings have been bred and they appear to be resistant to the DED.
According to a new report, the elm tree can finally return to the British countryside, given a helping hand…
Read the full report ‘Where we are with Elm’ by Future Tree Trust here:
Here at chXout we carry out species identification of all plants, animals and fungi. If you would like to find out the species of an insect, tree or fungi, then collect a sample using our Citizen Science Kit and we will use DNA testing technology for species identification!