Island gigantism on Sakhalin and the Kuril Islands

The Russian island of Sakhalin lies north of the Japanese archipelago. During the Qing dynasty, the island was once part of China, but later it was claimed by both Russia and Japan. In 1875, Japan ceded its claims on Sakhalin to Russia in exchange for the northern Kuril Islands. Several wars made the situation problematic, because in 1949 Russia 'stole' the southern Kuril Islands from Japan, thus breaking the 1875 agreement.

But that's not what makes Sakhalin and the Kuril Islands interesting, because the islands are known for their megafauna. Plants like grass, burdock, dropwort and others can reach up to two or even three meters in height. On some Kuril Islands grass can grow up to five meters in height.

Meadowsweet (Filipendula ulmaria) can reach up to 2,5 metres in height - twice the size of the ones on mainland Russia. Buckwheat (Fagopyrum esculentum), meanwhile, grows up to four metres, despite only measuring around 50 centimetres on the continent. Local publications often publish articles on how to get rid of the annoying weed, which has a tendency to pop up in people’s vegetable patches. The plant is able to adapt quickly and is effective at spreading into new territories.

The huge plants of Sakhalin interested scientists back in Soviet times. Trying to find the answer to the question of gigantism, geologists were transplanting these herbs to the European part of Russia, but the burdocks would only grow to their normal continental size. French specialists, back in 1935, tried growing Sakhalin buckwheat, but achieved the same results - it grew to its ordinary, everyday size. They only got monsters when experimenting with the species on the island.

What is the reason for this local megafauna?

It turns out that gigantism doesn’t affect all plants on the island - just those that grow above the places where the Earth’s upper crust has cracked. These places of tectonic activity contain ultra-wet soil, rich in copper, cerium and chrome, which are likely to have a positive effect on the resulting size. Therefore, this megafauna is a strictly local phenomenon.

One of the most popular dishes of Sakhalin is a starter made from gigantic marinated burdock leaves. They are sold in stores, served in cafés or prepared at home. Its taste is said to resemble that of meat.