While nearly all farmers understand the necessity to maintain the optimal level of organic material and humus in their fields to sustain tonnage production, very few realize the slow insidious leaching and depletion of the life giving minerals (mining) from their land - after all we pay them for tons and bushels, not for an analysis of minimal levels of various minerals in each carrot, potato, broccoli, or bushel of wheat or rice! This belief is summed up in a statement by a professor of soils from Iowa State College of Agriculture Henry Cantwell Wallace (George Washington Carver's favorite teacher and editor of the Wallace's Farmer )
"Nations endure only as long as their topsoil."
The statement should relay the message that"Nations endure only as long as nutritional minerals are available in their top soils!"
DEFORESTATION
Logging and Deforestation
The small farmer plays a big role, but it is modern industry that too cuts down the trees. The logging industry is fueled by the need for disposable products. 11 million acres a year are cut for commercial and property industries (Entity Mission 1). Peter Heller found that McDonald�s needs 800 square miles of trees to make the amount of paper they need for a year�s supply of packaging, Entity Mission found that British Columbia manufactures 7, 500,000 pairs of chopsticks a day, and the demand for fuel wood is so high that predictions say that there will be a shortage by the year 2000. Logging does too have its repercussions. The logging industry not only tries to accomplish all this but it even indirectly helps the "shifted cultivators" and others to do more damage. The roads that the loggers build to access the forests and generate hydroelectric power create an easy way for many people to try to manipulate the forest resources. The amount of damage that this adds to the forests can not be measured nor can that of the illegal logging. Some importers may even be buying illegally logged wood and not even have known it ("Logging is the Major Cause of Global Deforestation � New WWF Report" 2).
Cattle Grazing and Deforestation
Another of the more devastating forces behind deforestation is cattle grazing. With the international growth of fast food chains this seems to be an evident factor in the clearing of trees today. Large corporations looking to buy beef for hamburger and even pet food seek cheap prices and are finding them with the growth of cattle grazing (Heller 3). In the Amazon region of South America alone there are 100,000 beef ranchers (Heller 3). As the burger giants of industrialized society are making high demands for more beef, more forests are being torn down. Statistics from less than a decade ago, 1989, indicate that 15,000 km squared of forests are used expressly for the purpose of cattle grazing (Myers 32). Once the trees are gone the land is often overgrazed. In some places the government wants this to happen. Cattle grazing is big profit that can�t be turned down.
Other Causes
Beyond the major causes of deforestation lie some supplementary ones that too stack the odds against forests around the globe. Acid rain and the building of dams have their share of harmful effects. The race to produce cash crops such as fruit, spices, sugar tobacco, soap, rubber, paper, and cloth has given cause to many to try to farm them by using soil and other products that can be retrieved by destroying the forests. Even those in industrialized countries may participate in the destruction of forests in the 3rd world. The need for products in industrialized countries drives production in other poorer, less developed countries. This production is at the cost of the trees and the services that they provide.
The Effects
Deforestation presents multiple societal and environmental problems. The immediate and long-term consequences of global deforestation are almost certain to jeopardize life on Earth, as we know it. Some of these consequences include: loss of biodiversity; the destruction of forest-based-societies; and climatic disruption.
What is Lost?
Deforestation is causing a loss of biological diversity on an unprecedented scale. Although tropical forests cover only six percent of Earth�s land surface, they happen to contain between 70% and 90% of all of the world�s species (Myers, 12). As a result of deforestation, we are losing between 50 and 100 animal and plant species each day (Myers 12). Inevitably, the loss of species entails a loss of genetic resources. Many of these species now facing the possibility of extinction are of enormous potential to humans in many areas; especially medicine. As of 1991, over 25% of the world�s pharmaceutical products were derived from tropical plants (Myers). By contributing to the extinction of multiple species of plants and animals, we might be destroying the cures for many of the diseases that plague the human race today.
The worlds forests, particularly tropical rainforests, are home to over 10 million members of the "last surviving intimately resource-based cultures" (GFF 3). Given the importance of forest products to the daily lives of forest peoples, the destruction of tropical forests entails the destruction of tribal populations as a whole. Aboriginal people world-wide have had their land literally stolen from them by governments and industries, whose intent is to turn "natural capital into hard currency" (Dudley 11). As the Global Futures Foundation states, "there have been more extinctions of tribal peoples in this century than any other�Even in the rare cases when forest dwellers are compensated for this loss, the changes visited upon their cultures by the inexorable expansion of industrial culture are devastating." Without a doubt, deforestation has had a profound effect on cultural diversity throughout the forest regions, and ultimately, the world.
The lushness of the world�s tropical forests is somewhat deceptive. Although these forests assume to be lush and full, the underlying soils are very poor, almost all the nutrients being bound up in the vegetation. The problem is that once forests have been cut down, essential nutrients are washed out of the soil all-together. This leads to soil erosion. As of now, about 80% of the soils in the humid tropics are acidic and infertile (Dudley 21). When there are no trees to keep the soil in place, the soil becomes ripe for erosion. It dries and cracks under the sun�s heat. Once the soil temperature exceeds 25 degrees centigrade, volatile nutrient ingredients like nitrogen can be lost, further reducing the fertility of the remaining soil (Myers 14). Furthermore, rainfall washes remaining nutrients into rivers. This means that replanting trees will not necessarily help to solve the problems of deforestation; by the time the trees have matured, the soil might be completely stripped of essential nutrients. Eventually, cultivation in the forest regions will be impossible, and the land will be useless. The soil erosion will lead to permanent impoverishment of huge land areas.
The social impact of soil erosion can be quite severe. Those who settle into the forest regions are forced to move every year or so due to soil erosion. They find areas where they can cultivate. When those areas are no longer good for growing, they move to another region.
Flooding is a quite serious consequence of deforestation. Clearing the forest dramatically increases the surface run-off from rainfall, mainly because a greater proportion of the rain reaches the ground due to a lack of vegetation which would suck up the excess rainfall. "Tropical forests can receive as much rain in an hour as London would expect in a wet month, and a single storm has been measured as removing 185 tonnes of topsoil per hectare" (Dudley 21). In tropical regions where the forests are dense, flooding is not as serious a problem because there is vegetation to absorb the rainfall. It is in areas where there is little vegetation that there is a problem. Hence, to avoid the disastrous effects of flooding, tropical forests need to remain dense and lush.
Although all consequences of deforestation are potentially serious, perhaps the most serious consequence is that of climate change due to the loss of trees. Earth has an atmosphere which contains a variety of gases, all in a delicate balance, to ensure life on Earth. One of these gases in Earth�s atmosphere is carbon dioxide; a gas which helps moderate heat loss to outer space. Insulating gases such as carbon dioxide are called "greenhouse gasses because their function is much like that of the glass in a greenhouse: they allow solar heat into the system, but discourage its escape" (GFF 3). Other greenhouse gases include methane, chlorofluorocarbons, nitrous oxide, and ozone. If there are additional greenhouse gases, there will be a gradual increase in temperature on Earth�s surface. This could lead to changes in weather patterns, sea levels, and other cycles in nature that directly affect life on Earth (GFF 3).
The process of greenhouse gas increase is quite simple. Carbon dioxide levels increase for a number of reasons; but one of the main factors contributing to the increase of carbon levels is decay of woody material. The only way to help moderate the levels of carbon dioxide in the atmosphere is through plant life. Alive plants and trees absorb the carbon dioxide from decaying plants and trees. With a decrease in trees and plant life (due to deforestation) it is much harder to moderate these levels. Ultimately, the amount of carbon will increase due to a lack of plant life present to keep the carbon dioxide levels in check. This whole process leads to an "albedo effect which reflects more heat and light back into the atmosphere than would be the case if the sun shone on green trees�" (Dudley 23). The bottom line is that the increase in the carbon level and other greenhouse gas levels into the atmosphere leads to an increase in temperature, and eventually a change in climate and weather.
CORAL REEF BLEACHING
The Ban on Coral Harvesting
Seven months ago the Animal Welfare Institute of Washington D.C. and the Underwater Ecological Society of the Philippines (UESP) embarked on a program to stop the continuous exportation of our already depleted coral reefs.
Coral Harvesting has been banned by a Presidential Decree, yet corals continue to get gathered in various provinces in the Philippines, notably the provinces of Batangas and Cebu, not to mention the many isolated islands of the achipelago.
As most of us know, the seas, rivers and streams are our major sources of protein food. But it is only because of the high diversity and productivity of our reefs that the offshore fishes are as rich as they are. And now, we are plagued with the fast degradation of this rich marine ecosystem.
How much longer will this situation prevail? Is it only the bureaucratic red tape that delays the implementation considerably?
With the kind assistance of Dr. E. Gomez of the U.P. Marine Science Center supplying the much-needed scientific information on the sad condition of our coral resources, the Ministry of Agriculture and the Ministry of Agriculture and the Ministry of Natural Resources have now express official concern.
Meanwhile, armed with an arsenal of documents and letters of concern, our Washington counterpart was able to hold hearings with the representatives of the US House of Representative and the Senate. Senator Warren Magnuson and Honorable John Breaux of the House will always remain by-words to us for the support and concern they have extended to the environmental and ecological problems plaguing small, developing countries, particularly the Philippines with regards to corals.
The final report and findings of an extensive study conducted under the auspices for the UP Marine Science Center indicated that the US continues to be the largest imported of our coral resources, taking at least 56 percent, estimated at 107,525 cubic meter from the total export volume. Europe takes 33 percent and Japan, 18 percent. In 1977, Italy took the No.2 position, overtaking, It is our dream that if we succeed in stopping coral importation in the United States, the other countries will follow suit, and thus eliminate the market. The gathering of coral has long been prohibited, yet the practice has intensified due to obvious economic reasons. There will always be pirates as long as there remains a feasible market.
At the rate our coral reefs and other natural resources are being depleted, it is feared that someday our fish supply will no longer be sufficient for the rapidly increasing population.
The latest communication from Washington indicated that the banning of Philippine coral had received no opposition in both the House of Representative and the U.S. Senate. The enactment of the Environmental Bill in two to three months is 95 percent. Whatever the good news may be, we in Asia have not learned to jump with joy, unless the fruits of our labor are seen.
We only hope that the state officials from the "coral states," Florida and Hawaii, will not complain that the banning of Philippine corals will increase pressure on U.S. corals, and thus delay, if not shelve the bill. Let us hope that selfish individuals will not be obstacles to Ecology... and our own future.
Coral reef bleaching means...
Bleaching, or the paling of zooxanthellate invertebrates, occurs when (i) the densities of zooxanthellae decline and / or (ii) the concentration of photosynthetic pigments within the zooxanthellae fall (Kleppel et al. 1989). Most reef-building corals normally contain around 1-5 x 106 zooxanthellae cm-2 of live surface tissue and 2-10 pg of chlorophyll a per zooxanthella. When corals bleach they commonly lose 60-90% of their zooxanthellae and each zooxanthella may lose 50-80% of its photosynthetic pigments (Glynn 1996). The pale appearance of bleached scleractinian corals and hydrocorals is due to the cnidarian’s calcareous skeleton showing through the translucent tissues (that are nearly devoid of pigmented zooxanthellae).
Photograph of a bleaching hard coral (goniopora sp) from Pohnpei, Micronesia. Photo taken by J Hoogesteger. Notice that the entire coral is not bleached, the polyps around the edges are still healthy.
If the stress-causing bleaching is not too severe and if it decreases in time, the affected corals usually regain their symbiotic algae within several weeks or a few months. If zooxanthellae loss is prolonged, i.e. if the stress continues and depleted zooxanthellae populations do not recover, the coral host eventually dies .
Three hypotheses have been advanced to explain the cellular mechanism of bleaching, and all are based on extreme sea temperatures as one of the causative factors. High temperature and irradiance stressors have been implicated in the disruption of enzyme systems in zooxanthellae that offer protection against oxygen toxicity. Photosynthesis pathways in zooxanthallae are impaired at temperatures above 30 degrees C, this effect could activate the disassociation of coral / algal symbiosis. Low- or high-temperature shocks results in zooxanthellae low as a result of cell adhesion dysfunction. This involves the detachment of cnidarian endodermal cells with their zooxanthellae and the eventual expulsion of both cell types.
It has been hypothesized that bleaching is an adaptive mechanism which allows the coral to be repopulated with a different type of zooxanthellae, possibly conferring greater stress resistance. Different strains of zooxanthellae exist both between and within different species of coral hosts, and the different strains of algae show varied physiological responses to both temperature and irradiance exposure. The coral / algal association may have the scope to adapt within a coral’s lifetime. Such adaptations could be either genetic or phenotypic.
Ecological causes of coral bleaching
As coral reef bleaching is a general response to stress, it can be induced by a variety of factors, alone or in combination. It is therefore difficult to unequivocally identify the causes for bleaching events. The following stressors have been implicated in coral reef bleaching events.
Coral species live within a relatively narrow temperature margin, and anomalously low and high sea temperatures can induce coral bleaching. Bleaching events occur during sudden temperature drops accompanying intense upwelling episodes, (-3 degrees C to –5 degrees C for 5-10 days), seasonal cold-air outbreaks. Bleaching is much more frequently reported from elevated se water temperature. A small positive anomaly of 1-2 degrees C for 5-10 weeks during the summer season will usually induce bleaching.
Graph of todays sea surface temperature anomolies. Provided by satelite data from NOAA analyzed to a 50 km resolution. Color bars represent .5 degrees celcius anomolyn increments, red is possitive anomolies, blue is negative anomolies.
Bleaching during the summer months, during seasonal temperature and irradiance maxima often occurs disproportionately in shallow-living corals and on the exposed summits of colonies. Solar radiation has been suspected to play a role in coral bleaching. Both photosyntheticaly active radiation (PAR, 400-700nm) and ultraviolet radiation (UVR, 280-400nm) have been implicated in bleaching.
Sudden exposure of reef flat corals to the atmosphere during events such as extreme low tides, ENSO-related sea level drops or tectonic uplift can potentially induce bleaching. The consequent exposure to high or low temperatures, increased solar radiation, desiccation, and sea water dilution by heavy rains could all play a role in zooxanthellae loss, but could also very well lead to coral death.
Relatively few instances of coral bleaching have been linked solely to sediment. It is possible, but has not been demonstrated, that sediment loading could make zooxanthellate species more likely to bleach.
Rapid dilution of reef waters from storm-generated precipitation and runoff has been demonstrated to cause coral reef bleaching. Generally, such bleaching events are rare and confined to relatively small, nearshore areas.
Rather than causing coral reef bleaching, an increase in ambient elemental nutrient concentrations (e.g. ammonia and nitrate) actually increases zooxanthellae densities 2-3 times. Although eutrophication is not directly involved in zooxanthellae loss, it could cause secondary adverse affects such as lowering of coral resistance and greater susceptibility to diseases.
Zooxanthellae less occurs during exposure of coral to elevated concentrations of various chemical contaminants, such as Cu, herbicides and oil. Because high concentrations of xenobiotics are required to induce zooxanthellae loss, bleaching from such sources is usually extremely localized and / or transitory .
Pathogen induced bleaching is different from other sorts of bleaching. Most coral diseases cause patchy or whole colony death and sloughing of soft tissues, resulting in a white skeleton (not to be confused with bleached corals). A few pathogens have been identified the cause translucent white tissues, a protozoan.
Mangroves are trees and shrubs that grow in saline coastal habitats in the tropics and subtropics – mainly between latitudes 25° N and 25° S. The saline conditions tolerated by various species range from brackish water, through pure seawater (30 to 40 ppt), to water of over twice the salinity of ocean seawater, where the salt has become concentrated by evaporation (up to 90 ppt).
There are many species of trees and shrubs adapted to saline conditions. Not all are closely related, and the term "mangrove" may be used for all of them, or more narrowly only for the mangrove family of plants, the Rhizophoraceae, or even more specifically just for mangrove trees of the genus Rhizophora.
Mangroves form a characteristic saline woodland or shrubland habitat, called mangrove swamp, mangrove forest, mangrove or mangal. Mangals are found in depositional coastal environments where fine sediments (often with high organic content) collect in areas protected from high energy wave action. They occur both in estuaries and along open coastlines. Mangroves dominate three quarters of tropical coastlines.
Why Mangroves are Important
Mangroves are critical spawning, nursery, feeding and transient shelter areas to hundreds of fish species, crustaceans and invertebrates and support an abundant and productive marine life.
Like all other animals, fish, shrimp, crab and other marine life in the sea need a safe place to grow, away from many predators. With their tangled and intricate root systems, mangroves are excellent nurseries, providing safe hiding places for young animals. The muddy waters around them are rich in nutrients from decaying leaves and organic matter produced by the mangroves themselves and also from the sediment that is trapped around the roots.
Many commercial marine species such as bangus (milkfish) and prawns spend their early life within the mangrove area where they find food and protection from predators. Juveniles of some deep sea fishes also spend some time in the mangroves before moving on to other ecosystems such as sea grasses or coral reefs.
In addition, mangroves are also habitats to shore birds, some species of mammals (monkeys, rats, etc.) reptiles and insects. These animals utilize the mangroves as places to roost, breed or take shelter from strong winds or heat of the sun. They also serve as shoreline sentinels and pollution sink aside from being a source of firewood, poles, charcoal, and tannin.
Mangroves are essential to fish production. They are extraordinary rich habitats that serve as life support systems to about 75 percent of fish species caught in the area as well as to indeterminate number of crustaceans and wildlife. A good number of marine fish and invertebrates live in mangrove areas at some stages of their life cycles and consider mangroves as their “homes”. Mangrove loss directly translates to losses in fish catch and food supply.
How Mangroves Provide Food for Marine Species?
When a leaf falls, it breaks up and decomposes into smaller pieces, until they become too small to be seen by the naked eye.
The decomposing plant matter is collectively known as detritus. Detritus is covered with large amount of small organisms which take up the nutrients in the leaves. Individually, these organisms are too small to be of much value to any larger animal, but together they form a coating around leaf particles which many different animals use as food.
Leaves eaten by animals are not totally digested. They are excreted almost intact, again coated with organisms, and then eaten by marine animals. This process is repeated several times, so that one leaf can literally nourish a juvenile fish for much of its life in the mangrove area. Mangroves contribute about 3.65 tons of litter per hectare per year. One hectare of healthy mangrove ecosystem produces about 1.08 tons of fish per year.
Other Uses of Mangroves
Mangroves protect coastlines from the onslaught of storms and wave surges. Their crowns, trunks and stems serve as physical barriers that help break the winds and waves, reducing their speed and intensity and subsequently their destructive impact. Scientists say that during such surges, at least 70-90 percent of the energy of wind-generated waves is absorbed, depending on how healthy these ecosystems are and their physical and ecological characteristics.
Mangroves are also capable of absorbing pollutants such as heavy metals and other toxic substances as well as nutrients and suspended matter. Mangroves therefore serve as natural wastewater filters, preventing many land-based and near shore pollutants from reaching deeper waters.
Mangroves are a good source of wood and timber, nipa shingles for housing materials, firewood and charcoal, and of poles for fish traps. Several mangrove species provide high-quality commercial timber, used for various building materials as well as for fuel. In fact, in the Philippines, mangrove wood has been widely used as fuel for bakeries due to their high heat and charcoal value.
Tannins from mangroves are also used to coat and preserve wood, nets and fishing gear as well as for cloth-dyeing. Some species of mangroves are also habitat to bees and are sources of honey and beeswax.
As breeding and nursery grounds for many fish species, mangrove areas are sources of wild fry and juvenile fish for the aquaculture/mariculture industry. In addition, mangrove seeds and propagules can be harvested and sold to reforest denuded areas.
Economic Value of Mangroves
In the Philippines, it is estimated that the value of a complete mangrove ecosystem ranges from US$500 to US$1,550 per hectare per year or at US$600/ha/yr or US$60,000/sq. km/yr.
The total gain to the Philippines for protecting its remaining mangrove ecosystem is substantial. Using the conservative estimate of value from direct benefits of only US$600/ha/yr, the Philippines gains at least US$83 million/year in fish production and potential sustainable wood harvest from the existing 138,000 ha.
Source: FISH (The Fisheries Improved for Sustainable Harvest) Project
The CRM Interpretive Center, Municipality of Talibon, Bohol 
