The latest research suggests that trees really hate wi-fi.
Dutch boffins have worked out that radiation from wi-fi networks causes significant variations in growth, as well as bleeding and fissures in the bark.
The problem affects all deciduous trees in the Western world.
Scientists from the TU Delft University and Wageningen University were ordered to investigate the problem by the city of Alphen aan den Rijn five years ago after officials found unexplained abnormalities on trees that couldn't be ascribed to a virus or bacterial infection.
Testing found the disease to occur throughout the Western world. More than 70 percent of all trees in urban areas show the same symptoms, compared with only 10 percent five years ago. Trees where you don't have any wi-fi were not affected.
The researchers think that besides the electromagnetic fields created by mobile-phone networks and wireless LANs, ultrafine particles emitted by cars and trucks may also be to blame. These particles are so small they are able to enter the organisms.
To solve the question the boffins exposed 20 ash trees to various radiation sources for a period of three months. Trees placed closest to the wi-fi radio demonstrated a "lead-like shine" on their leaves that was caused by the dying of the upper and lower epidermis of the leaves. This would eventually result in the death of parts of the leaves. Wi-fi radiation could inhibit the growth of corn cobs.
Conclusions are a way off yet, but it is starting to look like if you want to save a tree you should switch off your wi-fi, or punch an iPad fanboy. The last bit is not related to the trees - we are just throwing out seeds.