Thursday, May 31, 2012

Unravelling the mystery behind the curved tree trunks near Budher caves


   It has been quite some time that I had some observations to write about the curved tree trunks that I noticed during my visit to Chakrata especially at Budher area which is located at an altitude of 2738 m approx. in the middle Himalayan ranges of Uttarakhand. Apart from noticing the rich biodiversity and enjoying tall trees especially the Deodhar and wild fox, birds, plants, etc.; the curved tree trunks kept on showing in almost all our treks especially on the upper reaches of the mountains. I was wondering if the Deodhar trees and others likewise have some growth problems. But the occurrence of groundwater oozing out from the rocks as springs and landslides were common phenomenon that were noticeable, where an entire slope had slid down and blocked the roads. Evidence of it was visible also on our walk to Tiger fall where the sides of the valley are loaded with evidence of past landslides. On which the people now do their terrace farming. Though people living in the mountains have a good system of selective logging for the trees when cutting for timber. I fear  that uprooting or cutting has made the slopes more prone and susceptible to landslides and degradation.

Area showing curved tree trunks at Budher, Chakrata, Uttarakhand(Courtesy: Google Earth)
Curved Tree trunks on the way to Budher Caves. (Photo Credit: Amar Oke)
Curved tree trunks on the mountain slopes. (Photo Credit: Amar Oke)
   But when I started connecting all these dots I started to realize that the trees has a message in its curved trunk growth at its base. As this became more evident when I bumped onto a research paper by R. Ian Harker from Department of Geology, University of Pennsylvania, titled “Curved Tree Trunks: Indicators of Soil Creep and Other Phenomena” published by the University of Chicago Press in the  The Journal of Geology, Vol. 104, No. 3 (May, 1996), pp. 351-358. The trees curved at the base that were studied at Mount Rainer National Park and the curved tree trunks of Budher area are very similar and fitting. The Budher area is underlined by limestone rocks which are shattered due to metamorphism and the water has carved out an interesting system of caverns underneath.

View from inside of the limestone cave. (Photo Credit: Nikhil Rajwade)
Stalactites inside the caves at Budher. (Photo Credit: Nikhil Rajwade) 

Spring water flowing down the gully.  (Photo Credit: Gurudas Nulkar) 
Water acts as a lubricating fluid for landslides. (Photo Credit: Gurudas Nulkar) 
      The trees grown on this terrain show curved trunk as a result of the unstable, brittle geology and also many external factors like snow/ice pressure, availability of light, catastrophic events and soil creep. These curved trunks at Budher are indicative of soil creep and are a useful indication of slope instability. Curves induced by soil creep are quite distinct from those from other factors mentioned earlier. His paper describes very well about this curved tree phenomenon. If the trunk curvature is of a character to be expected on selected slopes as a result of soil creep then similar such studies should be carried out by The Geological Survey of India to ascertain any impending dangers to the ecosystem and the local people. As the purpose of this is that we protect this fragile  landscape from further degradation. Not to mention the extent of how the winding roads have made the slopes more prone to instability.

Himalayan Pit Viper near Budher. (Photo Credit: Nikhil Rajwade) 

Common bluebottle butterfly at Budher. (Photo Credit: Nikhil Rajwade)