Dr Abe V Rotor
Living with Nature School on Blog
Paaralang Bayan sa Himpapawid with Ms Melly C Tenorio
738 DZRB AM Band, 8 to 9 evening class, Monday to Friday
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It's all skin, its owner makes the loudest and longest love
song among trees - the male cicada (kuliglig). Take note of the lichens growing on the trunk of an ilang-ilang tree. They belong mainly to the foliose type. The thick dark green growth on the upper part is moss, a bryophyte. Bryophytes are the simplest member of the plant kingdom. They are indicators of good climate: abundance of rainfall and high relative humidity.
738 DZRB AM Band, 8 to 9 evening class, Monday to Friday
It's all skin, its owner makes the loudest and longest lovesong among trees - the male cicada (kuliglig). Take note of the lichens growing on the trunk of an ilang-ilang tree. They belong mainly to the foliose type. The thick dark green growth on the upper part is moss, a bryophyte. Bryophytes are the simplest member of the plant kingdom. They are indicators of good climate: abundance of rainfall and high relative humidity.
The fact is, lichens play a symbiotic role with the host tree, a relationship whereby the lichens gain foothold that enable them to reach out for the sun and to occupy space with least competition with other organisms. One the other hand, the tree is protected from pest and effects of environmental change like drought.
The lichen in itself is an interesting specimen. A lichen is actually a group of two distinct genera of different kingdoms in the phylogeny of living organisms - alga (Kingdom Protista) and fungus (Kingdom Mycophyta) or in other cases bluegreen (Cyanophyta, Kingdom Monera) - living inseparably, a relationship developed through the long and uncertain process of evolution.
Instead of each member developing its own adaptation, the two joined forces so to speak, in order for both to survive. It is a perfect example of evolution through
cooperation, instead of competition as in most cases of evolutionary success.
The alga being photosynthetic manufactures food which it shares with the fungus. The fungus on the other hand, being saprophytic, converts organic matter back into elemental forms which the alga again uses. Such a relationship consists of an enduring cycle - season in season out, year in year out, covering a span of hundreds if not a thousand years. Such a feat is among the wonders of the living world. If the
Redwood or Sequioa is the longest living individual which is estimated to be up to three thousands years, the lichen is the longest living union (mutualism).
cooperation, instead of competition as in most cases of evolutionary success.
The alga being photosynthetic manufactures food which it shares with the fungus. The fungus on the other hand, being saprophytic, converts organic matter back into elemental forms which the alga again uses. Such a relationship consists of an enduring cycle - season in season out, year in year out, covering a span of hundreds if not a thousand years. Such a feat is among the wonders of the living world. If the
Redwood or Sequioa is the longest living individual which is estimated to be up to three thousands years, the lichen is the longest living union (mutualism).
The key to such success through mutualism lies not only in highly efficient nutrient exchange, but gas exchange principally CO2 and O2, as well. More so, for their ability to transform rocks into living mass which they share with other living things in their own time and in the future. They are the precursors of succession in the living world. Which points out to another evolutionary tool - benevolence - the sharing of resources albeit destructive competition.
More than this general knowledge there is very little we know about lichens. One thing ecologists are learning about lichens is the fact that they are a natural indicator, a sort of barometer, of environmental conditions. They thrive best where the air is clean, temperature change is moderate, so with relative humidity, the vegetative cover undisturbed, the rivers and lakes full, etc. And that lichens thrive best where man's intervention is least - if ever there is.
Yet lichens are found in the most difficult areas like the Arctic and desert, on rock cliffs, even dilapidated and abandoned structures. Their resistance as well as vulnerability to changing environment has led scientists to use the lichen as a biological indicator.
It leads us to the simple philosophy of a old man living near the summit of Mt Pulag in Benguet, reminiscent of the American philosopher Henry David Thoreau who lived by a pond (Walden Pond) deep in a woodland far away from town.
Yet lichens are found in the most difficult areas like the Arctic and desert, on rock cliffs, even dilapidated and abandoned structures. Their resistance as well as vulnerability to changing environment has led scientists to use the lichen as a biological indicator.
It leads us to the simple philosophy of a old man living near the summit of Mt Pulag in Benguet, reminiscent of the American philosopher Henry David Thoreau who lived by a pond (Walden Pond) deep in a woodland far away from town.
Here on the country's second highest mountain, 'Tang Ben, when asked on how Nature is kept pristine - even without first explaining to him the scientific basis of diversity and balance - simply quipped with confidence and sparkle in his eyes.
"Just leave Nature alone."
---------------------------------------Lichens: Enduring symbiosis of algae and fungi living as one complex organism
Lichens are indicators of clean air, in the order of increasing pristine condition:
crustose, foliose, fruiticose.
How do you rate the place you are living in?
Crustose lichen with juvenile fruticose lichen (branching)
Foliose lichen (leaf-like)
Young colony of squamous-foliose type of lichen on the trunk on acacia. Note its spreading and coalescing growth that will soon carpet a large area. Lichen is a closely knit association of algae and fungi in a state of symbiosis.
Fruticose lichen (right) hangs on tree trunk. In spite of its epiphytic nature it does not harm its host because it is not parasitic. It shares however with the water and nutrients collected by the tree from rain and dust, as well as from the gradual wearing out of the bark tissues.
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It has been estimated that 6% of the Earth's land surface is covered by lichen. Lichens are informally classified by growth form into:
· crustose (paint-like, flat), e.g., Caloplaca flavescens
· filamentous (hair-like), e.g., Ephebe lanata
· foliose (leafy), e.g., Hypogymnia physodes
· fruticose (branched), e.g., Cladonia evansii, C. subtenuis, and Usnea australis
· leprose (powdery), e.g., Lepraria incana
· squamulose (consisting of small scale-like structures, lacking a lower cortex),
e.g., Normandina pulchella
· gelatinous lichens, in which the cyanobacteria produce a polysaccharide that absorbs
· gelatinous lichens, in which the cyanobacteria produce a polysaccharide that absorbs
and retains water.
Part 2: Bryophytes, Bridge of Evolution in the Plant Kingdom.
“Ah, but what good is rock when it loses the essence on which life rises?” - avr
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Liverworts clinging on the lighted face of a rock. Like higher plant, they need sunlight to manufacture food by means of photosynthesis. The lower photo is stressed by limited moisture as summer approaches.
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Mosses make a carpet of soil which is actually the weathered surface of the rock. Bryophytes produce acidic substances that break down compounds of calcium, phosphates and other materials. It is this soil layer that invites higher plants such as isang dakot na bigas at the left.
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Luxuriant growth of green alga on a tree trunk which is being invaded by moss. Soon the colony will be dominated and subsequently replaced by the latter. Succession in the plant kingdom is common among simple plants, more so among higher plants in forests, swamps, grasslands, and all ecosystems.
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Mature foliose type of lichen, named after its leaf-like structure, grows on the trunk of pine tree in Benguet. This is the intermediate type of lichen, crustose being the simplest, and fruticose the most advanced.
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Mature colony of liverwort wear down as summer approaches, drying up in the process. But come next rainfall, a new colony develops in its place. Dried liverworts and mosses are gathered as substrate for growing seedlings and orchids.
Part 2: Bryophytes, Bridge of Evolution in the Plant Kingdom.
“Ah, but what good is rock when it loses the essence on which life rises?” - avr
Liverworts clinging on the lighted face of a rock. Like higher plant, they need sunlight to manufacture food by means of photosynthesis. The lower photo is stressed by limited moisture as summer approaches. 
Mosses make a carpet of soil which is actually the weathered surface of the rock. Bryophytes produce acidic substances that break down compounds of calcium, phosphates and other materials. It is this soil layer that invites higher plants such as isang dakot na bigas at the left.
Luxuriant growth of green alga on a tree trunk which is being invaded by moss. Soon the colony will be dominated and subsequently replaced by the latter. Succession in the plant kingdom is common among simple plants, more so among higher plants in forests, swamps, grasslands, and all ecosystems.
Mature foliose type of lichen, named after its leaf-like structure, grows on the trunk of pine tree in Benguet. This is the intermediate type of lichen, crustose being the simplest, and fruticose the most advanced.
Mature colony of liverwort wear down as summer approaches, drying up in the process. But come next rainfall, a new colony develops in its place. Dried liverworts and mosses are gathered as substrate for growing seedlings and orchids. Imagine a lowly moss as a tree, and a liverwort as a large green carpet shaped like a liver. A hornwort has pinnacles in Gothic style. It is when you are small that you see small things big, and big things present themselves as giants.
Observe a piece of rock covered with bryophytes. Under the magnifying lens you are looking at a miniature forest. It is thick and every space is taken by structures that look like stalks, leaves and other parts. On closer look these are not true organs because they lack vascular tissues, which in higher plants are for conduction of water and food and in providing support to the plant.
Ask the algae, the lichen, the moss and the liverwort. ~