Sri Lanka Upper Montane Rainforest Biodiversity
Cloud Forests Horton Plains World's End Nuwara Eliya Pidurutalagala
Apr 11, 2009
Sri Lanka's dense biodiversity, one of the world's ecological hot spots, has been documented since the olden days by Ibn Battuta and Marco Polo. Today, scientists and laymen alike have pored over fascinating information on the importance of its geological origins, location and climatic history.
When the supercontinent, Pangaea, disintegrated 200 million years ago, the rift created trenches, new oceans and two large land masses, Gondwanaland and Laurasia. These land masses continued to separate through the ages, and are now the planet's present-day continents and countries.
Cloud Forests of Sri Lanka
Professor Peter S. Ashton, Harvard University, in his foreword written for Wolfgang Werner's book, Sri Lanka's Magnificent Cloud Forests, wrote, "The mountain forests of Sri Lanka,...once attached to Antarctica, are of great interest to...history and present composition of the world's centres of biodiversity."
Some species found on these mossy or misty forests also show similarities with cloud forest species existing in South India and the Himalayas. Werner observed different characteristics between rainforests in the lowlands, like that of Sinharaja, a UNESCO World Heritage site "Man and Biosphere Forest Reserve," to that of Horton Plains to World's End, and the ones on the hills of Nuwara Eliya to the top of Pidurutalagala (2,524 m), Sri Lanka's highest mountain.
Differences Between Lowland Sinharaja Forest Reserve and High-Altitude Tropical Cloud Forests
While Sinharaja is characterized by two main types of forest: Dipterocarpus (flowering plants of tropical lowland rainforest) on the valleys and lower slopes, and Mesua-Doona (Shorea) or Na-Dun trees on the middle and upper slopes above 500 meters, on the other hand, tropical cloud forests feature "umbrella-shaped tree crowns and small, coriaceous leaves" and thick moss cover, vibrant tree ferns, lichens and other climbers. With fog cover, temperatures are lower, water evaporation is also slower, so these forests have no need for a lot of rain to nourish its vegetation.
Flora and Fauna Endemic to Sri Lanka's Upper Montane Rainforests, Palaearctic Immigrants
Two interesting features of Sri Lanka's upper montane rainforests are its endemic flora and fauna. These forests harbor plant and animal species not found anywhere else. Though there is baffling evidence of "palaearctic immigrants" from the Himalayas, such as Rhododendron arboreum and Satyrium nepalense, most of its inhabitants are natives, or lowland members that have evolved over the years, to better adapt to existence in higher altitudes.
There's Calophyllum walkeri (Clusiaceae), with round fruits and round leaves, colored rusty-red when new, found mostly on Horton Plains and Pidurutalaga. Cinnamomum (Lauraceae) is another prominent specie, and is related to the cinnamon plant of lowland forests.
As for cloud forest animals, some of the species are shared or represented in lowland ecosystems, like Cervus unicolor (sambar deer), Muntiacus muntjak (barking deer), or Sus scrofa (wild boar) and three species of primates. Panthera pardus (leopard) is the largest prey-hunting animal of the cloud forests. Elephas maximus (Asian elephant) disappeared from these high altitude rainforests around 1948.
Unique species include Rattus montanus (nillu rat), Feroculus feroculus (Kelaart's long-clawed shrew), Solisorex pearsonii (Pearsons' long-clawed shrew), and birds Zosterops ceylonensis (Ceylon white-eye) and Pycnonotus penicillatus (yellow-eared bulbul).
Natural and Man-Inflicted Damage to Cloud Forests, Canopy Die-Back Phenomenon
These beautiful cloud forests have not escaped nature's and man's destructive tendencies. According to Werner, illegal cutting of cloud forest trees, constant grassland fire, frost at the canopy, strong, "dessicating" winds and drought have all contributed to the infliction of damage to these upper montane rainforests. One of the most visible traces of destruction due to natural causes is the "canopy-dieback phenomenon" that can be observed while traversing the footpath from Horton Plains to the top of Totupolakanda (2,357 m).
Exploring Cloud Forests in Nuwara Eliya, Pidurutalagala, Farr Inn, World's End, Horton Plains
For those who want to explore cloud forests, Werner warns that one should never venture into these hills alone, except on regular routes or footpaths, like those ones from Nuwara Eliya to Pidurutalagala, and from Farr Inn to the 1,000 meter-high World's End cliff on Horton Plains.
As global warming starts to wreak havoc in many parts of the world, it is imperative that these thick forest cover should be preserved, to control soil erosion and to lessen the threat of floods. Luckily, Werner adds, the government of Sri Lanka has designated several nature reserves to protect these vital areas.
Reference:
Werner, Wolfgang. Sri Lanka's Magnificent Cloud Forest. Sri Lanka:WHT Publications, 2001.
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