We live in a world that appears to be moving at a pace faster than ever before. In that, environmental change – of our own making – has become an unfortunate repercussion of the human experience. In India, most of us can relate to changing cities and sprawling urban cancers that are unrelentingly eating into the peripheral countryside. And globally, the evidence of climate change brought about by human industrial activity is now too strong to ignore.

There is, however, a less familiar story of change in the Western Ghats, where several years ago, an enthusiasm for fast-growing forests replaced native montane grasslands and ushered in a host of ecological changes.

The Palani Hills in Tamil Nadu have played host to these changes and a series of both alarming and curious outcomes. The Palanis are a south-eastern spur in the longer 1,600km-long Western Ghats. This heterogeneous assemblage of hills, mountains, forest-cloaked valleys, and thirst quenching rivers are recognised as one of the “hottest” global biodiversity hotspots and a UNESCO-designated World Heritage Site (CEPF/UNESCO). The Palani Hills are named for the temple town of Palani, which is home to the most important Murugan temple in India. Kodaikanal is the principle large settlement and is an important Indian hill-station drawing tourists, school children and a host of colourful citizens from near and far (the township’s alarming growth and the strain on its carrying capacity is an important topic but is not the subject of this photo essay).

The physical geography of this part of the Western Ghats has given rise to a variety of fascinating ecosystems and habitats. The hills form a lofty plateau averaging about 2,000m in height, with escarpments dropping to the plains on the northern and southern sides. These slopes are covered with a variety of scrub, deciduous and evergreen forests, as well as grasslands. The higher hills, which the scientists now calling sky islands (Robin et al*), are quite different from the surrounding plains and slopes and host isolated populations of organisms. The upper Palani Hills once had large areas of the shola/ grasslands mosaic, a unique type of ecosystem similar to the upper reaches of the Nilgiri and Anaimalai Hills.

Up until the 18th century, there is relatively little evidence of human-induced disturbance in the Palani Hills. There are megalithic dolmen sites on the hills up to approximately 1,000m with scattered indigenous groups still living on the lower slopes. The upper plateau does not show any sign of significant human population (unlike in the Nilgiri Hills) until the arrival of American missionaries and British civil servants in the early 19th century. At the time, the area hosted a shola/ grassland mosaic habitat that was contiguous with the rest of the High Range-Anamalai block.

The establishment of Kodaikanal as a hill station in 1845 triggered significant ecological changes in the eastern plateau area, including the creation of an artificial lake and the introduction of non-native plant species. Fast-growing timber species (Eucalyptus sp. etc.) provided fuel and shade and visitors introduced ornamental flowers, shrubs, fruit and vegetable species.

White-bellied Blue Robin or Shortwing (Sholicola albiventris), an endemic species closely associated with sholas. (left) Male gaur (Bos gaurus) in a mixed plantation on the Ten Mile Round near Kodaikanal. Numbers of gaur have risen dramatically in the Kodaikanal settlement area. (right)

The western part of the upper plateau did not see major changes until the 1960s, when the forest department started to systematically replace montane grasslands with non-native timber plantations. The three prominent species used in plantation were Acacia mearnsii, Eucalyptus globulus and Pinus sp. At the time, grasslands were categorised as “wasteland” and there was little appreciation for the complex shola/ grasslands “mosaic” ecosystem (Bunyan*)), especially their role in the hydrology of the hills (and plains) and as a repository of biodiversity. Aggressive plantation expansion and logging continued into the early 1990s; after which, growing awareness in the Tamil Nadu Forest Department, as well as court cases relating to tannin factories in Coimbatore, brought operations to a halt. By then, there were few montane grasslands areas in the western upper plateau that had not been impacted.

Nilgiri Pipit (Anthus nilghiriensis), an endemic species associated with montane grasslands. (left) Relatively undisturbed grasslands below Ibex Peak in the remote Palani Hills. (right)

Eucalyptus plantation near Kodaikanal. (left) Illegal shola wood cutting in Kukkal shola. (right)

*** This photo story was originally published by Nature in Focus on February 17 2017. The design and layout of this page has been inspired by the talented NIF web team. ***