Cenchrus longispinus (Hack) Fernald, one of the most aggressive alien plants on the Romanian black sea coast

Abstract

Cenchrus longispinus (Hack) Fernald is one of the alien plants with a quick spreading on the Romanian Black Sea coast. Big populations of longspine sandbur have been recorded in Mamaia, the biggest resort on the Romanian Black Sea coast, situated near Constanța city, one of the most important harbors of the Black Sea. In some areas of Mamaia, longspine sandbur is already occupying large surfaces of the beaches and is causing discomfort to the tourists who walk barefoot on the sand. Smaller local populations and isolated specimens were recorded on the beach between Mamaia and Năvodari, in Constanta harbor, in Constanta city (in Tăbăcărie park) and on the beach of Vama Veche, a small resort close to the border with Bulgaria. In the coastal area of the Danube Delta Biosphere Reserve, longspine sandbur has not been noticed yet. The spreading of this alien plant in the coastal area depends on humans and animals. Its spiny burs are dispersed in many ways such as clinging to the fur of animals, shoes, clothing, or car tyres. Cenchrus longispinus was accidentally introduced in Mamaia resort most likely by the tourists, or through the goods trade in the resort. Constanta harbor could also be a gate for the entering of this species on the Romanian seacoast. The quick increase of the sandy surfaces infested by Cenchrus longispinus over the past 5 years in Mamaia resort and north of Mamaia, indicates the high ability of the species to occupy new territories and the risk of its spreading along the coastal area of Romania in the neighboring countries. Mowing the colonies with longspine sandbur and the meadows infested with this noxious weed, before the maturing of the burs is a non-polluting method for the control of this alien species.