Agasthya 5.2 When will the tree flower next?

All natural ecosystems and social systems are dynamic where change is a constant phenomenon. With global changes happening all around us, long term monitoring of such socio ecological systems as they are called these days has become a necessity. Easier said than done, long term monitoring not only requires resources, permits and field support, but also commitment from both institutions and individuals involved in the monitoring. Therefore questions like what and where to monitor becomes critical and careful selection of sites and parameters that helps us understand the dynamics of the system, is essential. In early 1990 following the general trend among ecologists to understand community ecology, a series of ecological monitoring programs evolved at Kakachi in the evergreen forest of KMTR. As part of this initiative vegetation dynamics, phenology of trees, pollinator and frugivore abundances and weather parameters are being monitored for the last 20 years at the site.

Trees don’t produce flowers and fruits every year; a familiar example is the availability of mango in the market that varies between years. In Kakachi where over 70 different species of trees are being monitored nearly 60% of them flower and fruit once in several years. Tricalysis apiocarpa, a tree of the wet evergreen forest whose flowers are pollinated by bees and fruits eaten by birds flowered only twice in the last 16 years and we have no clue as to when the next flowering will happen.

There is a considerable variation in the intensity of flowers and fruit set between the years, among the annually flowering and fruiting tree species. Response of animals to such events could be dramatic. In 1994 Palaquium ellipticum, a bat dispersed species, showed a very high intensity of fruiting than its normal years which brought an exceptionally huge number of bats to the site. This year, while carrying out our phenology observations, we noticed a high intensity of flowering levels which could lead to a super abundance of fruits too and perhaps a recurrence of the 1994 phenomena. Similarly Cullenia exarilliata, another annually fruiting species produces flowers and spiny fruits (cover picture) during season of fruit shortage in the forest. It helps many fruit eating animals, like lion tailed macaque and bats, tide over periods of fruit scarcity.

The forests of Kakachi are very stable and free from anthropogenic disturbances and major climatic perturbations. But with the climate not what it is, would the forests remain the same? Are perturbations in flowering, fruiting and recruitment observed a result of natural variations or influenced by changes in weather? Long-term monitoring of plants, phenology and animals which now also include amphibians with climate modelling may help us answer such questions and also get a deeper understanding of how species respond to climate change.

& nbsp;