my-own-planet-Earth

Way before trees appeared on Earth, animals and other land plants were scattered among the land masses. And way before land plants came the land animals. How did it all happen, and where did they all come from?

They came from the oceans, where just a few billion years earlier the first animal life evolved followed by plants. So, you see, the occurrence of trees was quite full of twists and turns and came about quietly long after land plants had struggled to rise from the oceans. Yet, their existence is the essence of all life on the planet.

There was a time about 550 million years ago when life "exploded" on the planet. Animal life. Nearly all of the animal groups in existence today -- as well as many that no longer exist -- first appeared on Earth during this time. It was the Cambrian Period, and this time of tumultuous and colossal animal diversity is called the Cambrian Explosion.

Land plants evolved a little more quietly about 90 million years later, with trees evolving some 100 million years after the first land plants began to emerge from their oceanic origins. But neither animals nor plants could have evolved were it not for the protection and nurturing of the ocean.

According to the fossil record -- about 3.5 billion years ago -- the first preserved life are found in the form of bacteria. They appeared in the oceans after the surface (crust) began to cool and stabilize, the land masses began to take shape, and clouds formed to produce massive volumes of rainwater that created the seas. The atmosphere was much different than today and the surface was unprotected from the Sun. This period is known as the Pre-Cambrian, the time that immediately followed the formative, molten and gaseous stage of Earth as it and the rest of the solar system started to come together -- or coalesce.

The first plants on Earth were a form of blue-green algae which appeared and lived in the oceans about 3.4 billion years ago according to the fossil record, protected from the harmful high energy radiation of the Sun. In the oceans, these plants were able to grow and photosynthesize as this high energy radiation was absorbed by the water. Now, to be perfectly clear about it, the first true algae (the kingdom protoctista) most likely made their first appearance about 2.4 billion years ago, but for sure by 1.8 billion years ago as the first acritarchs.

Although animals were the first life forms on Earth, it was plants that paved the way for land animals to evolve. Plants did this by simultaneously increasing the percentage of oxygen in the Earth's atmosphere and decreasing the percentage of carbon dioxide, a powerful greenhouse gas (Journal Science, August 2001).

Still, if you were to travel back about some 470 million years ago, Earth would seem lifeless, inhospitable and very barren. For one thing, no trees -- no plants at all -- lived on the land !

The first land plants made their appearance way before trees started driving their roots into the hard crust of Earth's surface, about 460 million years ago in the Ordovician period. Algae were the first land plants, moving from their aquatic origins to marshy and wet environments on land. It took consistent growth and diversification of land plants -- including the eventual evolution of trees -- to help break up the mostly iron-clad surface of the Earth.

Rising Out of the Ocean

To move from the water to land, plants had to adapt systems that would support their weight, provide transport of water and nutrients throughout their system, protect them from drying out, and insulate them from the sun and temperature changes. Obviously, if these adaptations were not difficult, plants would have moved on to land much earlier in the geological history of the Earth. Instead, they appear rather late in the history of life on this planet.

Trees first appeared and began to cover the land surface of the Earth some 370 million years ago. Today, we are so used to and dependent on trees that it's hard to believe that animals could have existed without them or that they did not at least simultaneously evolve together in the beginning.

Trees, with their large and thick roots, helped break up the rocky crust of Earth's surface to create the soil that would allow the development of new plant species, including other trees. And it was the greater evolution of plants and trees that enabled the evolution of larger and more diverse land animals, including mammals. (Keep in mind that the first land animals - bugs - were plant eaters, and they required more and diverse vegetation to evolve.)

But what was the first tree? And what made it a tree?

The First Tree...and Forests

First of all, it's important to understand that what makes trees unique from all other plants is they all have wood. Wood is a much tougher, thicker and reinforced fiber necessary for trees to hold themselves up under the pressure of their weight. As plants began to evolve and diversify, this fortification was necessary in order for them to branch out into much larger and heavier plants. As such, the evolution of wood is synonymous with the evolution of trees.

The earliest known modern tree is the Archaeopteris, a tree that looked similar to a Christmas tree with buds, reinforced branch joints and wood similar to today's timber. Its branches and leaves resembled a fern.

Over the past 370 million years, countless new tree species have evolved and eventually became extinct - like the archaeopteris - as the Earth's land masses moved about, climates changed, animal populations increased, and, of course, new species of plants evolved to take the place of the extinct ones.

Trees Today

Today there are approximately 100,000 known species of trees that exist throughout the world, according to World Resources Institute. A recent report from the United Nations Environment Program World Monitoring Center confirms that over 8,000 species are threatened with extinction and 976 of those are in a critical state.

(While it is important to note that these figures are not necessarily precise, they are the result of careful and comprehensive monitoring by field scientists worldwide. In as much the same way that it is currently impossible for us to know exactly how many animal species exist and have even died out without being discovered, it is also impossible to know exactly how many tree species currently exist or have existed on this planet.)

The Quiet Truth about Trees

Trees are vitally important to world health on all levels. Globally, forests are essential to the health of ecosystems and their functions, biodiversity and economics. Some of the many key functions of forests include climate regulation, the cycling and distribution of nutrients, and the provision of raw materials and resources. Trees cleanse the air and provide oxygen, help soil retain water, shield animals and other plants from the sun and other elements, and provide habitat for animals and plants. They help regulate the climate, cycle and distribute nutrients and provide raw materials and other resources. And don't forget the awesome beauty they give us throughout each year!

Several economic estimates -- including a report by Mark Baird, Indonesia Country Director for World Bank -- state that forests provide approximately US$1,000.00 per hectare -- or about $4 trillion -- in goods and services annually (Source: Forest Crime as a Constraint on Development, 9/13/2001). However, Mr. Baird points out that this figure "does not account for lost biodiversity for which there [is] no agreed estimating methodology."

Moreover, just one-fifth of the world's original forest cover remains in large, contiguous areas of relatively undisturbed forest. These forests are called frontier forests, the largest of which exists in Russia.

But before we start blaming human greed, there is an important principle about ecology and how all species depend on other flora and fauna in order to evolve, grow and become healthy. For this to happen, some species must pass on in order that new species can live and evolve.

Take the dinosaurs for instance. They died out some 65 million years ago -- along with 70% of the total species on Earth at that time -- which made room for the evolution of new species. Humans came along towards the end of this new evolutionary chain effect. Not to oversimplify the matter, but technically, if the dinosaurs had not died out, humans may not have evolved.

"It's All About Tradeoffs..."

"It's all about tradeoffs," says Emily Matthews, senior associate for World Resources Institute in Washington, DC. "The whole sustainability world is thinking about tradeoffs. What are we humans prepared to give up in order to have something else and still maintain the environmental goods and services we need?"

Indeed!

And so, humans have cleared forests primarily for their resources, to build cities and housing, and for agriculture. Industrialization has also been a significant contributor to the loss of our forest cover. When you consider that the world population has grown by more five billion people since the beginning of the Industrial Revolution, you can just imagine how much the world's forests have been counted on to meet human needs!

According to United Nations estimates, approximately one billion people lived on the planet by 1800 -- the early years of the Industrial Revolution. The population would rise to about 1.7 billion by 1900 and to 2.5 billion by 1950. Then the human population exploded! Over a period of 50 years, the population would increase 2.5 times to roughly 6.3 billion people today.

From 1990 - 2000, about two percent of the world's forest cover - roughly 10 million hectares - was lost and not recovered, according the Food and Agriculture Organization (FAO). That rate continues today. As it is today, the forests were mostly converted for agriculture, housing and city expansion (see urban sprawl) to meet the growing demands of the growing population. And therein lies the key to our dilemma!

Dynamics of Deforestation

The fact is, forests are being cut down and not replaced at a high rate in developing countries where their human populations are growing and their healthy development requires more use of land for agriculture, housing and roads, according to World Resources Institute's Ms. Mathews.

"In the developing countries, even with replanting, there is a big net loss," says Ms. Matthews. "Why? Their population is growing fast, they are building their economy and growing food to support themselves. Some developing countries are also major producers and exporters of timber for industrial use."

In developed countries, however, forest cover is "fairly stable," according to Ms. Matthews, "but there is still a certain amount of depletion of natural forests."

"In other words, developed countries' populations have somewhat stabilized, but they are still showing a certain aggressive appetite for clearing trees. The difference is they are in most cases replanting at least what they reap." But Ms. Matthews is quick to point out that new planting is not equivalent to old forests and cannot replace their value.

The Key

Certainly, stabilization of human population growth and wise use of resources are key to a majority of today's ecological, public health and economical challenges. As the human population grows, sustainable development appears not only logical, but essential.

According to American Forests, healthy cities should have an average tree canopy coverage of forty percent to ensure their ecological, economic and social sustainability. Rural areas should set a goal of at least fifty percent. But for many nations, the demand for resources from the forests are giving way to expansion and massive deforestation.

Still, says Deborah Gangloff, executive director for American Forests, the human population growth has helped us realize the importance of trees. "Understanding the changes we've made on the landscape helps us understand how we can take steps to revitalize it," said Ms. Gangloff. "We do know that planting trees is one of the most cost-effective ways to capitalize on the natural services provided by healthy ecosystems."

If the 'sustainability world' is smart about it, our forests will continue to evolve...quietly, and function, quietly, as guardians and vital instruments of Earth's ecosystems.

Did You Know...?

Thank you for your attention!:)

some days ago I chatted with some people. One of them was a student from China. Look what a nice memo he sent to me: my name in Chineese and a name of my country in Chineese. I like this gift very much:)
THANK YOU VERY MUCH DEAR CHATTER OF MINE:)
Hope to meet you soon again:)

Generally I have to say the guy was probably from Beijing or another big city like that -as much as I remember and told to me many interesting facts about historical prejudices between Chineese and Japaneese people dating back to IIWW and earlier.

And finally last - but not least - some historical things about China from Wikipedia:

Chinese Pre-history

Archeological evidence suggests that the earliest occupants in China date as long as 2.24 million to 250,000 years ago by an ancient human relative (hominin) known as Homo erectus. One particular cave in Zhoukoudian (now known as Peking) has fossilised evidence dating to 300,000 and 550,000 years old. Evidence of primitive stone tool technology and animal bones in association to H. erectus have been studied since the late 18th century to 19th century in various areas of Eastern Asia including Indonesia (in particular the Island of Java) and Malaysia. Originally it is thought that these early hominis first evolved in Africa during the Pleistocene. It is thought that human evolution first took place in Africa expanding 7 million years. By 2 million years ago the first wave of migration from the species in association with H. erectus settled into various areas in the Old World.

Fully modern humans (homo sapiens) are believed to originally have evolved roughly 200,000 and 168,000 years ago in Ethiopia or Southern Africa (ei. Homo sapiens idaltu). By 100,000 to 50,000 years ago modern human beings settled in all parts of the Old world (including the New World, Americas 25,000 to 11,000 BCE). By less than 100,000 years ago all proto-human populations disappeared as modern humans took over or drove other human species into extinction. It remains a controversial subject to whether fully modern humans evolved from separate H. erectus populations (known as "multiregional") as some evidence in ancient bones show a transitional change from H. erectus to H. sapiens having archaic features. However it is now more widely accepted that all modern humans genetically share a direct ancestor, a female nicknamed "Mitochondrial Eve" from Eastern Africa 150,000 years BCE. This model is known as Mitochondrial Eve Hypothesis.

The earliest evidence examples of fully modern humans in China come from Liujiang, China where a cranium dates 67,000 years BCE. Another is a partial skeleton from Minatogawa being just 18,000 years old.

China was one of the earliest centers of human civilization. Chinese civilization was also one of the few to invent writing independently, the others being ancient Mesopotamia (Sumerians), India (Indus Valley Civilization), the Mayans, and, some hold, Ancient Egypt—though it may have been learned from the Sumerians.

The first dynasty according to Chinese historical sources was the Xia Dynasty.

Until scientific excavations were made at early bronze-age sites at Erlitou in Henan Province, it was difficult to separate myth from reality in regard to the existence of the Xia Dynasty. But since then, archaeologists have uncovered urban sites, bronze implements, and tombs that point to the possible existence of the Xia dynasty at the same locations cited in ancient Chinese historical texts.

However, the first confirmed dynasty is the Shang, who settled along the Huang He river, dating from the 18th to the 12th centuries BC. The Shang were in turn invaded by the Zhou (12th to 5th centuries BC), whose centralized authority was slowly eroded by the ceding of state-like authority to warlords ruling small states; eventually, in the Spring and Autumn period, many strong independent states, in continuous war, paid but nominal deference to the Zhou state as the Imperial centre. They were all unified under one emperor in 221 BC by Qin Shi Huang, ushering in the Qin Dynasty, the first unified centralized Chinese state.

This state, however, did not last for long, as it was way too authoritarian, destroying many sources of competition for power that were also sources of good governance and development, such as scholars and intellectuals. After the fall of authoritarian Qin Dynasty in 207 BC came the Han Dynasty which lasted until 220 AD. A period of disunion followed again. In 580, China was reunited under the Sui. Under the succeeding Tang and Song dynasties, China reached its golden age. For a long period of time, especially between the 7th and 14th centuries, China was one of the most advanced civilizations in the world in technology, literature, and art. The Song Dynasty fell to the invading Mongols in 1279. The Mongols, under Kublai Khan, established the Yuan Dynasty. A peasant named Zhu Yuanzhang overthrew the Mongols in 1368 and founded the Ming Dynasty, which lasted until 1644. After the Ming dynasty, came the Qing (Manchu) dynasty, which lasted until the overthrow of Puyi in 1911.

Oftentimes regime change was violent and strongly opposed and the ruler class needed to take special measures to ensure their rule and the loyalty of the overthrown dynasty. For example, after the foreign Qing (Manchus) conquered China, because they were ever suspicious of the Han Chinese, the Qing rulers put into effect measures aimed at preventing the absorption of the Manchus into the dominant Han Chinese population. However, these restrictions proved ineffective against the assimilation of Manchus into the Chinese identity and culture.

In the 18th century, China achieved a decisive technological advantage over the peoples of Central Asia, which it had been at war with for several centuries, while simultaneously falling behind Europe in that respect. This set the stage for the 19th century, in which China adopted a defensive posture against European imperialism while itself engaging in imperialistic expansion into Central Asia. See Imperialism in Asia.

However the primary cause of the decline of the Chinese empire was not European and American interference, as the ethnocentric Western historians would lead many to believe. On the contrary it was a series of internal upheavals. Most prominent of these was the Taiping Civil War which lasted from 1851 to 1862. The civil war was started by an extremist believer in a school of thought partly influenced by Christianity who believed himself to be the son of God and the younger brother of Jesus. Although the imperial forces were eventually victorious, the civil war was one of the bloodiest in human history - costing at least twenty million lives (more than the total number of fatalities in the First World War). Prior to this conflict a number of Islamic Rebellions, especially in Central Asia, had occurred. Later, a second major rebellion took place, although this latter uprising was considerably smaller than the cataclysmic Taiping Civil War. This second conflict was the Boxer Rebellion which aimed to repel Westerners. Although secretly supporting the rebels, the Empress, Ci Xi, aided foreign forces in suppressing the uprising.

In 1912, after a prolonged period of decline, the institution of the Emperor of China disappeared and the Republic of China was established. The following three decades were a period of disunion — the Warlord Era, the Sino-Japanese War, and the Chinese Civil War. The latter ended in 1949 with the Communist Party of China in control of mainland China. The CPC established a communist state—the People's Republic of China—that laid claim to be the successor state of the Republic of China. Meanwhile, the disorganized and potentially corrupt ROC government of the Kuomintang fled to Taiwan, where it continued to be recognized as the legitimate government of all China by the Western bloc and the United Nations until the 1970s, when most nations and the UN switched recognition to the PRC.

The United Kingdom and Portugal transferred their colonies of Hong Kong and Macau on the southern Chinese coast to the PRC in 1997 and 1999, respectively. China used in a modern context often refers to just the territory of the PRC, or to "Mainland China" (the territory of the PRC excluding Hong Kong and Macau).

The PRC does not recognize the ROC, as it claims to have succeeded the ROC as the legitimate governing authority of all of China including Taiwan. On the other hand, the ROC—while never formally renouncing its earlier claims or changing official maps that show its territory as including both the modern-day PRC, Mongolia and Tibet—has moved away from this former identity representing its rule over all of China, and increasingly identifies itself as Taiwan. The PRC has historically resisted the ROC's identification of itself as Taiwan, especially in light of the movement supported by residents of Taiwan and others who advocate Taiwan's identity as an independent political entity. Significant disputes persist as to the nature and extent of China, possible Chinese reunification and the political status of Taiwan.