An invasive species of grass closely resembling bamboo is being removed from Mistra Valley to stop flooding and allow indigenous plants to flourish in the area.

The giant reed known as qasba kbira grows up to six metres high and is very commonly found along valley bottoms on the island.

The invasion of this species has caused environmental damage and has led some rubble walls to collapse, Environment Minister José Herrera said at a press conference on Friday.

Environment minister Jose Herrera and principal scientific officer at Ambjent Malta Alex Borg

Increasing biodiversity in the area is the greater scope of the project, said a spokesperson for Ambjent Malta, the government entity running the project. Oleander and other indigenous plants will be planted in place of the bamboo-like grass.

Ambjent Malta principal scientific officer Alex Borg explained that the giant reed was introduced to the islands a long time ago and has since taken over the area, causing damage to the local habitat.

“Every time it rained, the water would be blocked from passing into the valley and instead would overflow into the road or flood the adjacent fields. This was causing soil erosion.”

A native species similar to the giant reed will be cultivated in the area to provide nesting ground for three bird species currently using the invasive grasses to nest, he added.

Asked by Times of Malta whether this bird species will be impacted by the current works, Mr Borg said Ambjent Malta had taken the decision to carry out the works in summer so as not to disturb the birds during their nesting season.

He added that the project would take place slowly to give the birds time to adapt to the changes.

Why was giant reed introduced to Malta?

The giant reed is probably native to the Eastern Mediterranean, parts of Africa and the southern Arabian Peninsula and is thought to have been brought to the Maltese islands in ancient times.

Giant reeds have been utilised for various purposes over the centuries. A little known local musical instrument known as żummara, was made from a piece of giant reed.

Until recently large quantities used to be harvested to produce blinds known in Maltese as ħasira, as well as fish traps (nases tal-vopi).

In Sicily, the giant reed is used to make a cannizzu while in Spain it is used to make cañizo. These are rectangular structures made of weaved reeds which are used as windbreakers and to cover roofs and doors, similar to the Maltese ħasira.

The Maltese kannizzata is derived from Sicilian. The word kannizzata is nowadays used for a vine trellis, a structure on which creeping plants can grow. Today these are made of wood or plastic.

A kannizzata can also be a float used by fishermen to provide shelter for the dolphin fish (lampuka). In the past, the kannizzata was made of reeds but nowadays they are made of palm fronds.