With the southwest monsoon anticipated to hit in a few weeks, semi-arid Delhi and its parched flora, fauna and wetlands await rejuvenation. The city will see ephemeral (small plants) redefine its landscape and insects like cicadas, butterflies and dragonflies will help in pollination and aid avifauna as prey.
TOI takes a glimpse at how the monsoon revives Delhi’s dwindling and fragile ecosystem by pampering its flora, fauna, soil, air and waterbodies, thereby strengthening them to sustain yet another year marred with degradation and extreme weather events.
Naturalist and environmentalist Pradip Krishen said, “Monsoon makes a big impact on plants with small root systems that can’t survive in summers, but are key to the ecological balance. They germinate with the first showers, change the landscape of the city by making it green, flower and lay seeds and die after the rains, leaving the seeds dormant till the next season. These small plants hold the key to the sustenance of Delhi’s ecosystem.”
“While these ephemerals attract several insects on which birds feed, once they spread across the landscapes and die, they become biomass that goes to the soil and nourishes it. The amount of living matter that comes with rain is much larger than all the trees put together. When they die, they increase the fertility and carbon content of the soil, which stops erosion, aeration and water retention. This is very important,” added Krishen.
Explaining how insects lead to multiplication of reptiles and amphibians that also sustain mammals and birds, Sohail Madan from Bombay Natural History Society (BNHS) pointed out that moths migrate en masse to Delhi during monsoon. They pollinate and are flying prey for birds. One can also see the entire lifecycle of a butterfly during this season. “Rains transform the entire ridge, revive groundwater and fauna. Without monsoon, Delhi will cease to exist,” he stated.
Geologist Shashank Shekhar said monsoon was important for the entire South Asia and Delhi, which has exceeded its natural carrying capacity. “There is a population-resources imbalance in Delhi. In absence of rain, this imbalance will attenuate further. There will be no water, no recharge and no Yamuna. Even crisis management won’t be possible,” he added.
Delhi is made of two key life-sprouting habitats—Aravali and Yamuna. According to Faiyaz Khudsar, scientist-in-charge, Yamuna Biodiversity Park, rains revive Yamuna by diluting its pollution load and refurbishing the floodplain by bringing silt, plankton, etc, and Aravali by mostly filling its depressions.
“Monsoon flooding is important for the river and dry area rejuvenation. At Aravali hills, several seeds germinate. Invertebrates spread the seeds, improve soil fertility and aid the greenery of the city yearlong,” said Khudsar.
Wildlife biologist Sumit Dookia said rain settles particulate matter, thereby purifying the air and cleaning leaves and improving tree heath.
Being an important birding hotspot, songs of the colorful Indian pitta and other birds, including hawk, cuckoo, Paradise flycatcher, Bee-eaters, etc, echo in the city during this season. “Indian pittas come specifically during the pre-monsoon period to nest and hatch in Delhi-NCR,” said Neha Sinha from BNHS.
Ecologist KS Gopi Sundar said, “Besides seasonal plants, monsoon brings to life lots of mushrooms and fungi that are a critical part of nutrition flows. It restores groundwater without which civilization will collapse, specifically Delhi because there are no alternative sources of water.”
“However, the best thing monsoon does for Delhi, a city that has survived centuries, is fixing its humane spirit. The monsoon shows that things improve, pollution lowers, and the Yamuna, wetlands and greenery revive. It reminds us that there is a functioning natural cycle of the city, which is very reassuring,” said Sundar.