Book Excerpt: A guide to the Peninsula’s indigenous floral wealth

Banyan Tree at a temple in Kannur, Kerala. Via Wikimedia Commons. CC BY 3.0

Within the covers of this book, there are over 190 species of trees and shrubs that once would have been found extensively across the plains and low hills of South India. Many are still commonly found along rural roadsides or tank bunds, while others can be found in the reserve forests and national parks, such as the tiger reserves of Mudumalai or Bandipur. Heading up to the hill stations of the south, such as Ooty and Kodaikanal, the roads pass through the natural habitat of many of these plants.

Another important place to find these native species is in the sacred groves around temples, particularly those connected to the deities of Ayyanar or Mariamman. It is easy to recognize these shrines found at the outer boundary of the village, as there are large, brightly painted horses standing at the entrance. Traditionally, each village would have designated the strongest amongst them to act as the guardian, and they were given the title of Ayyanarappan. They would dwell in the forest on the village outskirts and ensure that no unwanted person enters the village with an evil intention. The villagers would pay tribute to this warrior, who was free to hunt in the forest. Over time, the necessity of this role was reduced and became more and more symbolic; hence today we find temples and icons. However, the belief remains that Ayyanarappan and the forest protect the people from flood, cyclone and other natural calamities and are also the source of food, herbal medicines and fodder.

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Aside from patches of forest, individual trees and shrubs are also found around the edges of agricultural lands, and in refuges tucked away in the inaccessible reaches of the hills that are scattered across the plains. In urban areas, they can often be found in city parks and green spaces. Of particular note is the extraordinary Guindy National Park in Chennai, which is predominantly made up of native species. Other urban parks, such as Cubbon Park in Bangalore, have of course been planted with exotic species over the years, but there are also native species to be found amongst the newer arrivals. Other places to find these trees in the cities include green spaces around colleges and government buildings. They may also be found growing in unexpected places, possibly as a result of a population that was there before the city grew up around it, or from a seed dropped by a passing bird.

The climate of the region has the greatest influence on the species composition of the forests, and is dominated by hot and dry summers, two monsoons, and rainfall patterns that vary from 600 to 1350 mm per annum due to the rain shadow effect of the Western Ghats and Sri Lanka. This rain shadow is particularly pronounced in the southern tip of the peninsula, and it is here that low precipitation-adapted species such as Balanites roxburghii, Albizia lathamii and Salvadora persica can be found.

As the foothills of the Western Ghats and central plains receive most of their rain from the southwest monsoon, the forests here tend to have higher concentrations of deciduous species such as Albizia amara, Hardwickia binata and Terminalia paniculata. These deciduous species tend to put out their blooms in February and March so that the seeds are mature and ready for the onset of the southwest monsoon that arrives in the summer. In contrast, the coastal regions, which have more rain from the northeast monsoon, have a greater concentration of evergreen species such as Diospyros ebenum, Memecylon umbellatum and Walsura trifoliata. In this situation, the flowering is less predictable, as the evergreen species tend to wait until the first spring showers have arrived before they open their buds. The perfume of their flowers, designed to attract pollinating insects or, in some cases, bats, adds a pleasant distraction to the hot summer breeze. As summer progresses, the seeds mature in time for the northeast monsoon that arrives in the autumn. These rains, blowing in from the Bay of Bengal, provide an extended growing season for the freshly germinating seedlings.

This effect of the two monsoons on the species composition of the forests is not a hard and fast rule as nature cannot be so easily boxed, but in general, it is seen that the Tropical Dry Evergreen Forests of the Coromandel Coast transition smoothly into the Tropical Dry Deciduous Forests as one moves further inland, or up into the small hillocks that are dotted across the plains of all the southern states.

The future of the forest

Until a few thousand years ago, the peninsula of South India would have been one contiguous forest stretching from the coastal belt, across the plains, and to the hills of the Western Ghats. Within this vast range there would have been a number of distinct forest types adapted to variations in rainfall, soil type and altitude. Animal and bird populations would have roamed freely throughout the area, adding their own signature to the landscape through grazing and other forms of disturbance. They would have also acted as agents of seed dispersal, ensuring the trees and shrubs were able to spread over the land to find specialized niches within which they could thrive.

Since the arrival of humans, some ten thousand years ago, the landscape has been fundamentally re-designed. Forests are confined to distinct patches, more often than not in areas unsuited to agricultural practices. Additionally, many of these remaining forests have been subjected to degrading practices, particularly during the colonial period, as timber was extracted, and the remaining species cut down and turned into charcoal to fuel the railways and industry. At this time, the deforested areas might have been replanted as monocultural timber or fuelwood plots or left to regenerate on their own after harvesting. In the latter case, the species distribution skewed towards the plants able to coppice from cut stems or those that managed to regenerate in the full sun while protecting themselves from grazing pressure through the presence of thorns.

Today, the majority of people living in these regions have little, or no, reference from which to visualize how the land once was. Nor can they imagine the beneficial effects that the forest would have bestowed upon the environment, in particular, ameliorating the harsh extremes of the climate in the hot summers, or reducing the impact of the intense monsoonal rains. Large areas are crying out for attention, most noticeably those currently covered with invasive exotic species, such as the Madras thorn (Prosopis juliflora), which is a species that can thrive in the current mix of grazing pressure and degraded soil. There are, however, many native trees and shrubs that are uniquely adapted to grow in these degraded lands, and if extensively planted through ecological restoration programmes, these areas would, in time, return to the ecological health once provided by the original forests.

Excerpted with permission from Trees of South India by Paul Blanchflower and Marie Demont. HarperCollins India