The Manu Rainforest: Part 2

Over the course of our stay in Manu our truly wonderful guides, Jose and Enrique, took us on:

* An introductory basic loop hike.

* A night hike.

* A raft tour of a huge Oxbow Lake.

* A canopy lookout 120 feet above ground in one of the countless gargantuan trees.

* A viewing of a Macaw claylick.

* A nightime viewing of a Tapir claylick followed by a night hike back to the lodge.

Dear god... I was once again unprepared for the stupendous quality of this experience. There was just so much to see and hear and smell and learn, it was almost overwhelming in its majesty!

The Intro Hike: While botany was an ever-present quality of Manu`s unofficial curriculum, this first hike was definitely the one most focused on it. Ye gods I completely understand Dr. Meloche`s fascination with plants now. There were so many incredible adaptations to life in the rainforest. First of all, the root systems of Amazonian flora are very wide and close to the surface as opposed to deeper and closer (radially) to the organism. This is because there is water in abundance in the rainforest, so unlike other species elsewhere in the world water is not the primary limiting resource and they don't have to send their roots as far down in search of it. Rather, they need nutrients! The surface soil of the rainforest is generally rich in nutrients due to the constant decomposition of organic matter (fungus and other decomposers are crucial in this, and really any, ecosystem). However, it is a shallowness of nutrients. Going straight down in Amazonian soil one will quickly hit sand, then clay, then bedrock. So, again, it makes sense for roots to spread out in all directions neat the surface then drill doggedly down.

As you may have heard, competition among plants in the jungle for sunlight is intense! The race to the canopy is vicious, with some small fraction of sunlight ever actually hitting the forest floor (while hiking it seems like night sets in hours before the sun actually sets). As such some truly remarkable and fascinating adaptations have evolved within this cutthroat environment. There are too many to divulge about here, so I will instead focus on the two most startling, unique, and to me just plain cool examples we came across.

First, there was the Strangling Fig tree, an awe-inspiring parastic plant. Parasitic may in fact be too misleading a word for this organism; I am more prone to consider it a carnivorous, preadatory angiosperm the likes of which would shame the more well-known Venus Fly Trap. This arboricidal creature first takes root at the very top of a host tree. From there it will start to send probing, creeping, almost vine-like extensions down the host tree until they eventually reach the ground and take root. In this seemingly backwards manner of growth it will, over several years, completely encase the host tree and leech nutrient from it; eventually killing, decomposing, and completely consimuning it. The end result is that the Strangling Fig becomes a massive, fully grown tree with ample access to canopy sunlight and soil nutrients (at which point of course the mature organism can get whatever it needs in a more traditional manner), which is completely hollow, consisting instead of a ring of tracheated stems. A fully-grown Strangling Fig with its host long-since digested will immediately jump out as a tree among the forest and beg investigation. Our group of course explored its inner cavity, discovering in the process that it creates new habitat for a variety of animal species, such as nesting bats. A final point of note about this organism is that Strangling Figs do not attack each other, you will never find one Strangling Fig consuming another.

Secondly, there was the Walking Palm. I still can't get over this remarkable fellow! A great many trees in the rainforest (as well as swamps, marshes, or anywhere where the substrate they grow in is exceptionally hydrated) have at their base a very broad, almost pyramidal root morphology which acts to stabilize the organism within its precarious position. Some trees, like the Penis Tree, will grow first from a stabilizing central root stem and then send out ancillary root shoots (which look extremely phallic) at triangular atragectories from their trunks which once submerged in soil will then create more stability as well as focus on nutrient extraction. The Walking Palm exhibits an extremely wonderous variation of this adaptation which demands a student's awe. As I have mentioned, competition for sunlight is highly intense in the rainforest. If the Walking Palm has taken root and grown up in a position with little or insufficient sunlight, or if it had enough sunlight but is now being denied full access because something taller grew up around it, the tree will, in all seriousness, start growing root shoots out in a particular direction (likely the one where it still recieves the most sunlight); they will take root and it will then detach from roots on the opposite end which were anchoring it to its previous pocation. Over a handful of years this palm tree can literally walk to a more advantageous position! It was inarguably one of the most spectacular things I have ever beheld and learned about (and of course, the obligate nerd in me immediatley thought of Treebeard and the Ents from Lord of the Rings =D).

There were countless more noteworthy exemplars of ingenious adaptation, the rainforest is truly the manifestation of a botanist's most private imaginations. For now however, we must move on to...

The Night Hike: If a tree falls in the woods and no one is around to hear it, does it still make a sound? This question is of course silly, and a good example of philosophers thinking themselves into inescabale Descartian bondages. We however were there to hear it, and it did make quite the sound! The night hike, intended to appreciate the diversity of nocturnal jungle stalkers (mostly invertebrate), began with a bang, or rather a crash. As we tramped down one of the few well-worn paths in this enivron, just after crossing our first bridge, an ominous crashing sound reverberated from the front of our line as a massive tree smashed smack-dab across our trail, mere feet in front of our guide, Enrique. It was quite the exhilerating start!

What followed was an exciting menagerie of nearly every cool critter which can fit in the palm of your hand imaginable. The only absentees were tarantulas =( and reptiles (though a very rare yellow-footed tortoise had been stumbled upon earlier during the day there were unfortunately no fer-de-lances or bushmasters to be found on this year's journey). Animal life abounded though. Every ten feet it seemed we found a massive, 2-inch legspan hunting wolf spider. Whispy moths fluttered everywhere and many different kinds of frogs were discovered underfoot. Remarkebale among the amphibians were one small species which gave the appearance of its entire body being just a big head, laying perfectly camoflauged among decomposing leaves. Then there was a great fat cane toad, of the same genus as the ones which were introduced with such disastrous effects in Australia, willing to eat anything it could fit in its mouth. Also, in accordance with the Jurassic Parky theme I have imposed upon this adventure, it was one of the types of toad spoken of by Dr. Allen Grant which has the ability to spontaneously change sex when there are no or not enough individuals of the opposite sex within a particular breeding range.

A 4-6 inch platyhelminthes, or flat worm, sporting a ribbon of purple coloration on its dorsal side was seen forging a slimy track across the trail. Spit-Bug nymphs metamorphosizing within their frothy cocoons could be found, as well as a sizeable Griffin Moth caterpellar. Rivers of nomadic army ants bustled through our path here and there (did you know that ALL army ant species are nomadic? There is some cool info on this phenomenon coming up in the journey to the Tapir Lick). Then there was the tree where we found both a small black scorpion hunting as well as a massive crab-like arthropod as big as your hand scurrying. This second one was a Tailless Whip Scorpion, and truly looked as if it belonged in some Primeval Silurian clime.

The coolest critter by far however was the Social Spider. We saw these frequently on the day hike, but it is more appropriate to mention them here. This particular breed of spider, otherwise rather small and unremarkable, exhibits the most stupendous cooperative social behavior, which is almost unbelievable because spiders as a rule are very solitary animals, only ever coming together (briefly) to mate. These guys however, are members of the same family who all construct a large matrice of spectral silk which varies in size based on the size of the colony (some of the largest ones create webs several meteres in diameter). Everywhere you look you see tiny earth-orange abdomens skittering about in a bustle, hapless hexapods harnessed everywhere (our guide has even seen hummingbirds trapped and dead in these webs, though the spiders don't eat them). A mating pair will establish a new colony, laying a typically large batch of eggs. However, instead of dispersing like most spiderlings do this species sticks together and creates a familial network which works together to construct and maintain the webbed scaffolding of their home and to share prey amongst themselves. They are not like ants or bees in that there is a queen individual and a regimented caste system which operates based on some kind of hive-mind; this is much more individualistic. The smaller webs will have dozens of spiders, and the larger ones can easily support a hundred or more of these fascinating organisms. It is especially hair-raising to shine your flashlight on one of the webs at night and see a see a mosaic of tiny green eyes reflecting back at you.

Alas, I must leave you waiting for the thrilling conclusion of Manu as it is late and I must get packed, we leave for the Galapagos Archipelago from Quito here tomorrow morning! I do not know if there will be any more internet for the remainder of the trip. If not, I will fill this thing out the moment I return. Hopefully there will be something though, we will see.