By Jis Sebastian
I was happy to leave Assam this time, unlike before… I was excited that I would start my Ph.D. now in the Western Ghats after three wonderful years of research experience in the northeastern Himalayas. After all, the Western Ghats was home, and I had never worked there before.
Orchids are one of the most fascinating groups of plants on Earth. I have always been fascinated by plants around me, thanks to a very inspirational teacher who encouraged me to study and specialise in plants. My teachers blessed me enough to fall in love with botany and forestry, as they themselves had. I clearly remember working in Eaglenest Wildlife Sanctuary in Arunachal Pradesh back in 2012. Researching animal ecology, I was mesmerised when the mist-covered hills revealed themselves to be an orchid paradise. The branches of conspicuous trees were heavily covered in mosses and epiphytic orchids—the kind of orchids that grow on top of trees. The beautiful flowers that welcomed me at every corner of the sanctuary; I was smitten. It got me thinking: do epiphytic plants like orchids prefer particular climates? Perhaps moist and foggy ones? Around the same time, a wonderful innovative project on epiphytic orchids was starting in the Western Ghats. I was selected, and thus, I bid adieu to the northeast after three long years. I was happy to leave Assam this time…
The big challenge before me was a lack of guidance; there was a lacuna in orchid ecology in India at the time. This resulted in me spending a year in the forests testing different methods. Finally, with the help of Giby Kuriakose, assistant professor of botany at Sacred Heart College and my project investigator, an integrated method called Linear Line Transect with Selective Tree Scanning (LLTSTS) was developed to study biodiversity patterns in epiphytic orchids. A ‘line transect’ was laid after finding a host tree with at least three individuals of orchids on it. Then, the next neighbour was selected at the 10th meter point from the first individual and this repeated until data collected from ten trees from each line transect. Such transects in a linear direction were widely carried out in different units of altitude/latitudinal gradients all over the southern Western Ghats in Kerala. How did factors like the host tree, habitat, and climate influence epiphytic orchids’ diversity, distribution and community structure? This was the major question of my research.
Single Rope Technique (SRT) is what is commonly used to access canopy epiphytes all over the world. In this technique, a single rope is used to ascend and descend a tree using lock and hold mechanism. The climber wears safety gear and uses specialised devices for both descent and ascent. But it isn’t possible in all terrains or forest types. So, we had to rely on high-powered binoculars as well. Data collection was time-consuming and strenuous. My already dislocated shoulders from long travels radiated pain towards the neck with frequent upward scans for orchids. However, it was also fun to lie on my back on the wet forest floor and scan the tree canopy. I collected data on the landscape features, tree characteristics and epiphytic orchids within the canopy on every transect. This kind of work can especially feel time-consuming and very exhausting. I was never able to get rid of the bloodsucking leeches off my toes that were already messed up due to the unknown fungal diversity I had picked up in Arunachal! I lost count of the leech bites once it crossed 6,000!
The world I observed through binoculars and from the canopy was breath-taking. I found that epiphytes do show preferences for specific microclimates (climate in the immediate surrounding). These preferences could be determined by different factors at different levels. Each host tree provides zones of microenvironments i.e., microhabitats with specific microclimate in a vertical gradient. Therefore, In a young tree, the epiphytes on the lower trunk, upper trunk, lower canopy, middle canopy, and the upper canopy could all be different species. The upper canopy receives more sunlight and is exposed to temperature variations and hence orchids that prefer these microhabitats are rootlike to prevent water loss. Epiphytes within the canopy can be of varying sizes and positioned according to different factors, such as the inclination of the branch with the trunk, orientation and position of the branch, light etc. There are epiphytic ferns like Drynaria that prefer to be downwards of the lower canopy to collect all the rich humus leaching from the upper canopy.
Different forest types support orchids. Tall evergreen forests have orchids mostly in the canopy, whereas, forests with canopy gaps have orchids in the lower canopy as well as the tree trunks. We defined the habitat at different scales such as mega (landscape), macro (tree) and micro (canopy). With no disturbance, these habitat levels create more microhabitats within themselves. The more the number of microhabitats in a forest, the higher the epiphytic orchid diversity is. So, these hanging flowers become an indicator for old, rich, undisturbed and complex tropical forests. Large-sized trees sometimes harbour huge epiphyte colonies over a long time. Therefore, big, old trees are important habitats for epiphytes and orchids. This gives answers to why planting trees is not equal to good old forests!
The climate of a region is also a predictor in explaining diversity and abundance patterns of epiphytic orchids. Hilly tracts with high moisture or relative humidity favour epiphytic assemblages. If light and temperature become higher than usual, it negatively affects the orchids. The underlying mechanisms behind these patterns have to be further explored, but we know enough to deduce that climate change, specifically warming, risk affecting these amazing plants.
These hanging flowers become an indicator for old, rich, undisturbed and complex tropical forests. Large-sized trees sometimes harbour huge epiphyte colonies over a long time. Therefore, big, old trees are important habitats for epiphytes and orchids. This gives answers to why planting trees is not equal to good old forests!
In my exploration of trees, I encountered many terrestrial orchids too. These ground orchids sometimes live on decaying matter (saprophytic) or on stones (lithophytic). Orchids can lift your spirits given how rare (and endangered) and beautiful they are. Coming across the critically endangered Paphiopedilum druryi can leave one stunned and hurt at the same time. I was once very surprised to find a handful of plants of the highly critical Malabar daffodils (Ipsea malabarica) in a private coffee plantation. This species had never before been seen in the protected areas! Interestingly, these plantations also support a high epiphytic load on their native shade trees.
My research in epiphyte ecology, still a nascent field in India, is just a beginning. There are many more questions to be answered and understood to conserve these ecosystems. Based on my research, I suggest a need for large scale – temporally and spatially – research to understand the trees, epiphytes, and their community networks. Further, integration of diversity-rich private land into conservation initiatives is what we need before we plummet into irreversible changes in climate forever.
It is difficult at times to stay calm on seeing orchid diversity threatened at different levels. Dr Giby and I carried out an orchid conservation outreach programme for the upper primary school students, coffee/cardamom plantation owners and workers, the Kattunaikkars – an indigenous community and forest watchers in Wayanad, Kerala, with support from San Diego County Orchid Society, California. The stakeholders have been given training to identify orchids, rescue them if they find a fallen or displaced orchid, and restore them to a similar habitat. I’m happy to say that the programme was a hit!
‘I feel pretty safe and comfortable in the forest. Dealing with the department staff, is tough. Once that is done, I feel free as the wind… I feel more scared when I’m in the city.’ – Excerpt from a profile of Jis we did back in Season 1 of TLoS. You can read the entire feature here.