Diversity felled by a taste for tea

When the British took possession of the island of Ceylon from the Dutch in 1796 they ruled only the littoral. The Kandyan kingdom straddling the extensive central highlands remained unconquered. The reason for this colonial anomaly was not military inadequacy but environmental extremes. To ensure their independence, the Kandyans used the dense, fever-ridden, leech and animal-infested rainforest encircling the capital of the kingdom as a protective barrier, permitting only easily defended footpaths through their domain.

On the downfall of the kingdom in 1815 the British assumed control of the destiny of a unique ecosystem. The Kandyan highlands provided many specialised environments that allowed for the evolution of a wealth of indigenous species. The area exhibited a higher degree of biodiversity than anywhere in Asia. This book details how the British and, to a lesser extent, the Kandyans, devastated this ecosystem in less than a century through the creation of coffee, cinchona and tea plantations.

Tropical Pioneers focuses on the ecological transformations of the highlands in the 19th century but the first chapters are devoted to much earlier changes that occurred elsewhere on the island and the Kandyan relationship to the natural world prior to the intrusion of the British.

James Webb Jr relates how the villagers acquired "highly nuanced understandings of highland ecological dynamics". Knowledge of the island's flora was evident in their indigenous system of Ayurvedic medicine and the diverse forest gardens they established. Even though they were obliged to adopt a slash-and-burn agriculture known as chena cultivation to augment their susceptible rice crops, this was episodic and isolated.

Webb describes how the British arrival in the highlands triggered a series of deleterious and often-irreversible ecological changes. The construction of a road system as an affirmation of conquest involved cutting the forest for a mile on either side of the highway. The arrival of cart traffic into the highlands brought with it rinderpest, which proved deadly to highland cattle and other fauna. In addition, the unravelling of the social fabric in the aftermath of the failed rebellion of 1817-18 led to the rapid development of the Kandyans' chena lands.

During the 1830s, the decline of British coffee plantations in the West Indies after the abolition of slavery precipitated a land rush in the middle highlands of Ceylon. The wholesale clearing of the forest and the introduction of a monoculture and unsound agronomic practices, such as weeding, created intense pressures on the soil. Natural imbalance caused plagues of rats and insect infestations. Finally, a fungal blight crippled the industry in the 1870s. After a short experiment with cinchona in which aggressive draining methods produced further soil erosion, the plantation industry switched to tea. With the success of this crop came the expansion of plantations into the upper highlands. "The loss of primal forest was unparalleled in British Asia," Webb states.

oven into this salutary tale is the thread of hope that leads to the enhanced environmental awareness of the 20th century: the enlightened thinking of certain individuals in the face of commercial pressure, and the establishment of research facilities in the wake of the coffee blight disaster. Extensively annotated, illustrated with period photographs and supported by a wealth of tables, Tropical Pioneers is a well-researched and succinct Asian environmental history that should appeal to the specialist and general reader.

Richard Boyle is a British-born film-maker living in Sri Lanka who has scripted several documentaries on the island's highland ecology.