A sudden gust of
wind, and a few bright red leaves of a grand Elaeocarpus break free, only to be unhurriedly carried away in the
clear waters of the stream flowing by. Unlike trees where the young leaves are
red and turn green, the leaves of the Elaeocarpus,
a species of wild rudraksh, turn a bright red as they age, sprinkling the brown
leaf litter of many a rainforest floor with its colour. A journey that started
as a bud attached to a branch has now reached its final stage; detached and
sailing away past massive buttresses of other elaeocarps, wild mango and jamun,
in the rainforests of the Anamalais. As they set sail, away from their
branches, they are joined by others—walnut-like
seeds of the same tree. They float past stream rubies defending their favourite
perches, past Danios and spotted barbs in the water, past rounded rocks and
overhanging bridges, past whistling thrushes and sallying flycatchers, past
tumultuous rapids and scarlet impatiens, to gently settle in the arms of a calm
pool.
Somewhere in the
same landscape—not far—a sudden gust
drops a few bright red leaves from another majestic elaeocarp. The stream
flowing by is subdued and silent, unlike its gurgling neighbour a few miles
away. The bright red leaves go with the flow, but there are no stream rubies
here, nor sallying flycatchers. Harsh light streams through the sparse
vegetation, in contrast to the soft, dappled light that a rainforest canopy
allows. Far fewer rounded rocks remain, many now resting alongside roads as
barriers. The water is slightly coloured, too, sluggish and slow to respond.
The journey ends abruptly, as the stream disappears into a swamp in massive tea
fields. Those few bright red leaves lend the only colour in a depressingly
monotonous green ocean of tea, clogged in a mat of rushes and swamp vegetation.
To understand the decay of streams, one has only to walk along a few in tea
plantations.
Wherever they
flow, streams have a character of their own. Whether in the mighty Himalayas or
the equally impressive hills of peninsular India, from roaring rapids and
rolling cascades to gurgling brooks, a stream is a strand that weaves life
together. And fragmentation due to tea and coffee plantations sever the strand,
converting fast-flowing streams to marshes and swamps. Vital meanders are
straightened to drain away what appears to be excess water, but this in turn
only leads to increased erosion and flooding. This is the decay of a stream,
and the plantation landscapes of the Western Ghats mountains are riddled with
such streams. Most streams that originate and flow through these areas end up
being dammed, diverted, mined and polluted. Their gentle meanders are
straightened, their laughter silenced; their only solace being a few isolated
rainforest fragments and protected forests of sanctuaries and reserves miles
downstream.
How do landscape
transformations affect the life of the streams and the life in the streams? Our
recent study on the Asian small-clawed otter, the smallest of the world's 13
otter species, threw up some pointers. In India, these otters are elusive
mammals mostly restricted to the hill streams of the Western Ghats, the
Himalaya and the North-east. For our study in the Valparai plateau of the
Anamalai hills, we walked along numerous perennial streams flowing through the
tea and coffee landscape, looking for evidence of otters. At first, the only
glimmers of hope in the streams running through the stunted ocean of tea was
the occasional grey wagtail or a flitting stream glory damselfly. Still, camera
trap photographs and spraints (droppings) revealed that otters were using these
streams. Coffee plantations with their shade trees, being more similar to
forest, fared slightly better than tea for otters, despite the release of
insufficiently-treated coffee wastewater into already-depleted streams. What
was crucial for streams and otters were, however, the few patches of rainforest
that had survived the onslaught of plantations. Retaining these while allowing
strips of natural vegetation to regenerate along streams can help revive stream
health and water quality, and prevent erosion and loss of wildlife habitat. It
is in these strips that streams can still hum a part of their original tune.
Towering trees,
an occasional herd of elephants crashing through and the sound of great
hornbills in the canopy were constant reminders that much of the Valparai
landscape was once like this. One early morning in April, in the adjoining
Anamalai Tiger Reserve, we watched a pack of dholes frolicking in the shallow
waters of a stream. They had killed a sambar the previous evening and had
returned to finish the remains. A couple of hours later, walking further
upstream, we glimpsed our first small-clawed otter. Too stunned to react, we
watched it disappear into a rock crevice. All these months of walking along
streams had finally paid off, however short-lived. Not wanting to surprise it
any further, we quickly moved on, walking upstream towards our destination—an
obscure waypoint marked on the GPS. We had barely arrived and were yet to
recover from having seen the otter when we heard a growl that could only have
come from a tiger! Moments later, the forest exploded with the alarm calls of
lion-tailed monkeys in the canopy. We watched as a tiger walked down to the
stream for a quick drink. The stripes of orange and black disappeared as
suddenly as they had appeared, the cacophony was soon transferred to the
neighbouring valley, and tranquillity reigned once again.
Most natural
systems are resilient in nature and if allowed to recover, these streams too
can perform vital ecological functions in modified landscapes and support a
substantial amount of biodiversity. Native riparian vegetation binds the soil
together and prevents erosion. Restoration of streams and riparian ecosystems
in modified landscapes also help in reducing conflicts and providing habitats
for native species of both flora and fauna. It also helps in reviving corridors
for movement of large mammals like elephants and gaur. The fact that otters and
other animals still use streams in plantations is hope enough that all is not
lost in this blind dash towards development.
