The neem tree growing out of doors my house is a shape-shifter. Once a year, without fail, in the cool dry winter its leaves turn out to be tired and yellow-brown, and every so often fall off totally. Just as the weather turns a bit warmer, heralding the summer, the neem miraculously becomes green again. Then the shy white flowers emerge, hiding in the foliage, difficult for the human eye to spot aside from from the hum of tireless pollinating insects and the scent of honey. Two months later, yellow-green fruits invite a menagerie of fruit-eating birds and animals to a summer feast, couriering seeds absent in their bellies, which would grow into shape-shifting neem trees elsewhere. At other times mosses, mushrooms, spiders, geckoes, squirrels, bugs, and the occasional snake lead their own secret lives in the shaded sanctuary of the neem.
The study of the seasonality of trees can tell a lot approximately the surroundings – even supply evidence for climate change. In temperate regions of the world, plants shed all their leaves in the extremely bloodless winters and can start growing again only after the warmer spring season arrives. The arrival of the growing season is outwardly visible in the form of new leaves. Global-warming induced climate change is now affecting the seasons – it is getting warmer earlier and cooler later in the year. During the last few decades, trees have been responding by putting out new leaves earlier and dropping leaves later than usual in the year. In the tropical latitudes where we are living, information on tree seasonality is difficult to come by, and subsequently the effects of climate change on these patterns is as yet unknown.
How can one detect such patterns, though? Through numerous research and data collected approximately a factor of interest. Here’s an illustration – take into consideration your height; it is most likely decided by genetics, but nutrition will also be a factor. The heights of all of the other humans you realize are also affected by their own unusual individual conditions. As a population of humans, we will be able to subsequently ascertain an average height with an estimate of the variability around it. Whether one detects an increase in this average human height through the years (say 150 years), one can speculate approximately the overall reasons (say, better childhood nutrition) for these changes occuring at the level of human populations.
It is precisely the same for quantifying seasonality in trees! Understanding seasonal patterns in trees requires information on the onset date of change, frequency of the change, and quantum of change over many years. Once this information is acquired, long-term averages and the variability in these patterns can also be ascertained, and the causes for shifts from known patterns can then be explored. To detect the effect of factors like climate change, one should first find evidence of environmental change (such as an increase in temperature), and then spot a corresponding departure from the expected long-term tree seasonality. Researchers are regularly logistically constrained in collecting information of this type, at large enough scales (of space or time), so as to reliably estimate the seasonality in living organisms. This is where non-professional scientists, trained in collecting the desired information, can contribute through citizen science projects to fill in gaps.
One such citizen science project documenting country-wide seasonality of common Indian trees is SeasonWatch. Since 2010, the project has collected > 4,00,000 observations on > 90,000 trees belonging to 134 common species of India. This long-term data has helped deduce the patterns of emergence of leaves, flowers and fruits of the most-observed species like Mango, Jackfruit, and Indian Laburnum. This information will now serve as a baseline to compare any future changes in these species. In the Indian Laburnum, SeasonWatch data showed a gentle advancement in peak flowering dates in comparison to culturally known peak flowering dates. If it is a result of climate change is a conclusion that may be arrived at only by observing more trees for more time. For now, I will be able to make a note of the arrival of flower buds on my neem tree, contributing to an ever-increasing repository of information, one tree at a time.
SeasonWatch is a citizen science project aimed at understanding the seasonality of trees, and the effects of climate change on this seasonality, across India. Students from more than 1200 schools and more than 1100 interested individuals contribute weekly information on tree species that are commonly found across the country. Anyone can turn out to be a citizen scientist with SeasonWatch by registering on the site as a contributor and registering as many trees as one wants for remark. There could also be a SeasonWatch Android app on Google Play, to help with making observations on-the-go.
Geetha Ramaswami is a Programme Manager at SeasonWatch, based at Nature Conservation Foundation. She is interested in all things plants, and finds their quiet lives intriguing and inspiring at the same time. She particularly enjoys studying plants that have gone rogue – invasive plants – and how they have interaction with animals.
This series is an initiative by the Nature Conservation Foundation (NCF), under their programme ‘Nature Communications’ to encourage nature satisfied in all Indian languages. To realize more approximately birds and nature, sign up for The Flock.
Is Mi 11X the most efficient phone under Rs. 35,000? We discussed this on Orbital, the Gadgets 360 podcast. Later (starting at 23:50), we hop over to the Marvel series The Falcon and the Winter Soldier. Orbital is to be had on Apple Podcasts, Google Podcasts, Spotify, Amazon Music and wherever you get your podcasts.