Equinoctal tree

Bombax ceiba, the silk cotton tree, (শিমলু in Ahom, শিমুল in Bangla, सेमल in Hindi) is the perfect symbol of spring. It sheds its leaves in winter, and produces red flowers in spring before it sprouts new leaves. In May, as the season of vasant shades into the heat of grishma in the northern plains of India, the fruits of silk cotton burst open and release the seeds centered in feathery gliders of silky thread that give the tree its name. That is a memory from my childhood; I haven’t been in the appropriate place and time since I finished my school.

So, when we came down from the middle heights to the plains, I was impressed by this treebeard, a giant standing as tall as the canopy on the higher slope on the far side of the Darjeeling Himalayan Railway track. It could have been 50 meters in height; I could reach a bit more than a fourth of the way around the trunk with my arms. The buttressing roots reached above my head. The only way I could take a photo was to make a vertical panorama. The tree grows above the canopy in order to catch the wind it needs for seed dispersal.

The wide dispersion across India of this native of rainforests made me believe that its origins are South or South-East Asian. Unfortunately, I could see very little study of its genomics and biogeography from this region. There has been intensive study in China in recent years, where it was imported in historical times from northern Vietnam (its flower is a symbol of the city of Guangzhou). I wonder when it reached Australia; it is pre-Colonial. What is the native Australian lore about it?

The six seasons: 2

Summer is the time of mangoes. In the part of the country where I grew up, the decisive beginning of grishma (summer) would be the brief week or two when the house would fill up with seemingly unending baskets of lychee. But they would be over before I could ever anticipate it, and suddenly one day the house would have the first mangoes of the summer. There are almost no lychees in Mumbai, and the summer starts with the delightful apoos (alphonso). The other delightful aspect of this, the most terrible of seasons, are the flowering trees. My favourite is the red of the silk cotton flower (Bombax ceiba), named after the silky feathers which waft through the burning air in May, carrying seeds from the burst fruits. On the other side of the road, peeking out from behind a building I can spot another favourite, the red flowers of the gul mohar (Delonix regia, the flame of the forest). The easiest to photograph from my window are the copperpods (Peltophorum pterocarpum, yellow flame) which line the roads around us. Nearby, and invisible to me now, is a jacaranda tree which must be in flower. None of these popular road-liners are native to Mumbai. The first rains of the next season will knock all these flowers off the trees, and for a few days the roads will be carpeted with vivid patches of colour decaying into mush.

But I’m getting ahead of myself. For now I can see the morning’s light moving along my kitchen wall. A couple of weeks ago the sun, as it rose, would burn me as I made my morning’s tea. Now that spot in my kitchen is safe, and the sun’s first light falls on the southern wall. The cool land breeze of the morning stops earlier now, and the equally cool sea breeze also sets in earlier. The sound of the birds has changed; perhaps they have moved to different parts of the garden, and someone else in getting the early morning concert that I would a few weeks back. In Mumbai you feel the summer more by an increase in the humidity as the sun warms up the ocean. I can feel it already.

Kaziranga: a managed forest

The famous grasslands of Kaziranga are not a self-maintaining system. This fact came as a shock to me. I’d thought of it as a nature preserve, where the balance is naturally maintained. I should have been aware of this, since the rhino-springback, for which it is famous, is a success story more than a century in the making. Nor can it be entirely natural, since it lies on the banks of the Brahmaputra.

On one of our drives through the park we reached the banks of the Brahmaputra. A shallow slope led down to the deceptively low waters. In recent decades the park has lost almost 14% of its area to erosion from the annual flooding of the river. Flood plains have their own ecology, which is often lost when rivers are dammed, or other “flood control” meaures are taken. However, the flooding of the Brahmaputra is a danger to the animals in the park.

We saw an ameliorative measure being taken. A few massive earth movers and trucks were going back and forth between the banks of a stream and a spot inside the woods. When we passed it, we saw an enormous earthen plateau being built up artificially. We asked our jeep driver what this was for. “Refuge area for animals,” he replied. With more questions we could tease out a detailed answer from him: the forest department was constructing an immense high ground where the animals could retreat in case of flooding. This was the first major piece of ongoing engineering we noticed inside the park.

Another thread was not at all obvious. I saw silk cotton trees with fruits and seed pods hanging on them. Many had fallen off the tree and burst open (see photo above). The winds were lifting the silk parachutes off the ground and wafting it about. It took many conversations for me to realize that this was a problem. Apparently, give the large areas of grassland, the seeds often fall on fertile ground. As a result, there is a spurt in the growth of these trees, leading to a shrinking of grasslands.

The solution that the forest department has adopted is to identify patches where the trees have taken hold, clear the larger trees and set a small controlled fire to kill the shoots. We saw little circles of blackened stumps rather often in a relatively small area. It would have left us mystified if we hadn’t had that conversation.

Many years ago I’d read a short story about a bridge being built on Jupiter by tele-operated robots, and disaster after disaster being averted by some quick action. Kaziranga reminded me of that. It has been one of the successes of wildlife conservation in India: with the rhino, elephant, numerous birds, several species of deer, and tigers being brought back from the edge of local extinction. That story ended badly, with several problems striking together. One hopes that Kaziranga can work things out better.