Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

The impacts of vascular wilt disease of the takamaka tree Calophyllum inophyllum on conservation value of islands in the granite Seychelles.

Abstract

The takamaka tree Calophyllum inophyllum is an important component of indigenous coastal forests in the granitic Seychelles, found on most islands of the archipelago. In 1994, a fungal pathogen previously unrecorded in the Seychelles (Leptographium calophylli [Verticillium calophylli]) was detected on takamaka. Since the first cases of the disease were observed, spread of the disease has been rapid, both within and between islands. Attempts to control the disease, involving both legislation and forest management, appear to have had little impact in controlling the spread. In the six years since the disease was first recorded in the Seychelles, it has reached 10 islands, including most of the large islands of the archipelago. Mortality rates and rates of spread between trees appear to vary in different islands and situations, but in some cases both appear to be high. This paper describes the distribution of the disease in the granitic Seychelles six years after it was first recorded, reviews the potential impact of the disease on conservation value and discusses management strategies to minimize the impact of the disease on endemic vertebrates.