Just back from a trek to Siruvani. As you work your way up from the bottom, you have dry scrub jungle to start with which gives way to dry deciduous as you keep moving (you're not climbing much here). Dry becomes moist deciduous which after about 600m MSL is transformed into evergreen rainforest. Keep climbing and you have grasslands at about 1000m above mean sea level. Now, climbing grasslands after the rains is quite tricky. Grasslands are said to be the glaciers of the non-alpine slopes and that is so very true. The loamy soil (black, in the case of Siruvani) soaks up water from the rains like a sponge and releases it slowly into the forest (which is why the evergreen patch is right below the grasslands, first in line to receive the water), throughout the year. Now, back to climbing grasslands: the lower grasslands are quite mushy. Plant your foot and it all seems very stable until you follow it up by weight transfer and your foot sinks deeper into the muck (which was dry mud a few seconds ago), more water is released all around, the ground begins to give way and slide under your foot and you end up with your arms flailing for support (but there are no shrubs, it's a grassland, remember?) and then, disaster! You've landed nose-first into some of the cleanest muck on this planet. Welcome to Siruvani!