Saturday, June 30, 2018

Tree as Ecosystem: A tree fell and took with it its tenants and symbionts.

Everything was quiet, then came a gust of wind from nowhere.  It sent a ten-year old samat tree crashing across our street.   
Dr Abe V Rotor
Living with Nature School on Blog

Workers in the neighborhood in Lagro QC clear the blockage to restore traffic flow and electricity. Samat or binunga (Macaranga tenarius) though sturdy is no contest to the power of wind. But where did the cyclone-strong wind come from in a fine weather?

I felt obliged to do my own research having been the one who planted the tree in 2003 from a seedling I got from our home in San Vicente, Ilocos Sur. I needed the mature and yellow leaves in making vinegar.  Marlo, my son needed the fruits in his thesis in the graduate school.  It is a source of tannin and other medicinal compounds.

Because of its thick crown year round , the tree is a good shade and buffer against noise and dust.  It was in this tree that birds that were not seen for many years suddenly appeared, among them the  kikiaw (kiaw Ilk) or yellow and black oriole thought to have become extinct locally. Migratory birds would find the samat tree a transient lodging place in their long migration at the onset of winter in the North which coinicides with our Amihan season when cold winds from Siberia sweeps across Asia down to the Pacific. 

Then there were house sparrows that found shelter in the tree's thick foliage. And not to be outsmarted was the pandangera or fantail bird. It would send a complaining sound if disturbed when sitting in her nest.  Or when a cat would get near the tree. The pandagera together with her mate would swoop down and scare the intruder until it scampers away.  

It was in this tree that the tragic pipit used to sing in high almost clicking notes. I could imagine the tragic end of this minute bird that sings its heart out to the world. To kill a pipit bird is likened to "to kill a mocking bird," of the same title by Harper Lee (1960). 

One time a nephew of mine came to the house holding a caged strange looking lizard, thinking I could make it a pet. I told him it's a gecko (tikka Ilk.).  I made the samat tree its new home.  Well, it stayed there for some time exchanging calls with our parrot which was actually imitating its love call. On discovering the hoax the disillusioned reptile left, presumably moved to the La Mesa watershed to join its own kind, a block away from our residence.  

The green tree ants regularly built a nest or two in the tree.  It was good because they controlled other insects, and they are good janitors.  They glean on any food leftovers on the ground, and kept the surroundings clean, especially around the doghouse. Houseflies don’t thrive on clean environment.  

When the tree fell it took with it the lianas, orchids, ferns clinging of its limbs. So with the lichens and mosses that are natural indicators of good air by their abundance.

You see, the tree is not just a tree.  It is a host.  A host of many organisms depending on it in various categories.  Call it parasitism for feeding caterpillars, symbiosis for ephiphytic bromeliads and orchids, commensalism for mosses and  lichens.  Free board and lodging for the seasonal perperoka. Fungi growing on the tree’s dead branch are saprophytes; bees and beetles and butterflies as pollinators. 

When new leaves form, photosynthesis gets a boost .  So the tree produces more food, and more oxygen that replenishes the carbon dioxide that we in the animal kingdom expel. And what happens to the “food” accumulated in the tree?  It is further made into complex organic substances – cellulose and lignin in wood which we harvest for construction, crafts and fuels. Tannin for cure of diabetes. Xanthophyll and carotene for vitamins and natural dye.  

All these attest to the tree’s vital role more than just a passive standing host.  It is a system in itself, an ecological system or ecosystem in short.

The meaning of this is that when the tree dies the whole system also dies. And the sad thing is that the loss is irreversible.

I mourn for the felled samat tree on behalf of the creatures that benefited from it that have too died.  Luckily for others, they migrated and hoped to find another benevolent host. ~   
But the puzzle remains.  Everything was quiet, then came a gust of wind from nowhere.  It sent a ten-year old samat tree crashing across our street.  

Theories are not rare to explain the incident. The most plausible is poor foothold. The tree was virtually sitting on adobe bedrock characteristic of the place in QC, so that its root system had no other way but spread sideways instead of downward with a tap root as principal anchor. 

There is a nearby drainage through which  various wastes flowed - oil, detergents, alkali and acid rain, ultimately finding their way into the root zone and destroying much of the roots. The tree however held on without apparent sign of toppling down.  

On the meteorological aspect, thunderstorms have become more frequent, as a consequence of global warming, a phenomenon that is not yet well understood. But global warming is spawning more - and stronger -  typhoons, hurricanes, and tornadoes all over the world. Extreme weather is now felt more often. Too much rainfall in one place causes flood, while too little rainfall is causing drought in another place. Freak weather disturbances are not unusual, among them was a sudden thunderstorm on that fine day when my favorite samat tree toppled across our street. ~      

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