Ancient Forest Type

Alerce (Fitzroya cupressoides)
The alerce is unique to the coastal temperate rainforests of southern Chile and the mountains of western Argentina. Sometimes called “the redwood of South America,” it is more accurately described as a relative of the cypress. The alerce reaches more than 150 feet in height and 13 feet in diameter. It is also longer lived than either the coast redwood or the giant sequoia of California, living 3,600 years or more (the bristlecone pine can reach 4,800 years). The alerce has a huge trunk, and its rough pyramidal canopy provides cover for the southern beech, laurel, and myrtle. It produces small, scale-like leaves and little round cones.

The alerce, like the western red cedar and redwood, contains resins that resist decomposition, making it especially valuable in exterior construction (for such materials as shingles, decks, and so forth). As a result of this and other attractions, such as its straight grain, the alerce has suffered from overcutting, which spirals into even more devastation because of the tree's low reproductive rate.

The last remnants of ancient alerce forest are hidden in the Andean cordillera. Some appear in the remote valleys, slopes, and terraces of the higher elevations of southern Chile as well as in a small extension in Argentina (normally above 2,100 feet). The alerce's range at one time extended from the coastal mountains south of the city of Valdivia east to the wetter valleys on the Argentine side of the Andes and south to the slopes of the Michinmahido Volcano—a range only about 150 miles long and 50 miles wide. Alerce thrives in the cool, rainy environment from 39 degrees to 43 degrees south. Chilean conservationists estimate that only 15% of the original alerce forests remain. Lowland tracts were totally eliminated by logging.

In 1976, the Chilean government designated the alerce a Natural Monument and outlawed the cutting of live trees (although it is legal to harvest them when fallen). In the same year, the Convention on International Trade in Endangered Species (CITES, Appendix 1) prohibited the international sale of alerce products. The species remains threatened by habitat loss from extensive hardwoods logging. Illegal poaching and burning of alerce are also problems, but not as great as that of legal, unrestricted logging of associated species. Large-scale clearing activity in the past, combined with the alerce's very slow growth, poor regeneration, and illegal cutting, seriously impedes any notable increase in the species' natural distribution.

Araucaria (Araucaria araucana)
Chile is home to one of the world's most fantastic araucaria forests. The araucaria's tall spindly trunk and unusual evergreen foliage give it a distinct form that can be recognized from miles away. An araucaria tree can live for 1,800 years and grow more than 8 feet wide and 185 feet tall. The ever-shrinking range of A. araucana is limited to a small region in the southern Andes. (Fossilized and living specimens of the genus are found in South Africa, Australia, some Pacific islands, Antarctica, Europe, Brazil, and North America). This species is unique for its genus in thriving in the temperate climate's warm, dry summers and cold, snowy winters. About 800,000 acres of forest lands contain A. araucana; only 125,000 are pure stands.

This araucaria species is also known as "Pehuen" (in the native Mapuche language) and the Monkey Puzzle Tree (because an Englishman remarked in the 1800s that it would be a puzzle for a monkey to climb). Botanists now recognize the araucaria as an “archetypal” tree, among the earliest families of seed-bearing plants. Araucaria forests were widespread on the Earth alongside dinosaurs in the Jurassic (carbon records date back at least 180 million years); the tree's armor of daggerlike leaves was designed to thwart the appetite of 80-ton herbivores. The araucaria yields large nuts in the fall.

The araucaria's Natural Monument status makes it illegal to cut; but this protection has been lifted before. Illegal logging occurs, and the large timber companies covet the last araucaria forests. Three-fourths of those that remain are on private lands. The publicly protected lands fall well short of what is needed to ensure the species' health and the long-term viability of the ecosystem. The Santuario Cañi is one of the araucaria's last refuges.

Cloud Forest
Cloud forests are known to be the most diverse terrestrial plant communities on Earth. They are easy to recognize by the misty forms that hover over them almost all year long. At altitudinal bands where air cools as it is forced over a mountainous region, a phenomenon known as adiabatic cooling causes clouds to form. The clouds deposit tiny drops of water on trees and plants, beginning a process called horizontal precipitation.

An abundance of moss, orchids, and bromeliads covers both the tree trunks and the forest floor; occasionally “moss forest” is used as a synonym. Ecuador is home to critical expanses of this forest type on both the west and east sides of the Andes. Some cloud forests have pine and fir trees, giving them the appearance of temperate forests. The steep slopes of the cloud forests provide an almost continuous canopy of tree cover, offering occasional spectacular views. In general, cloud forests are found in headwaters areas and contribute significant precipitation to watersheds. Despite their importance, cloud forests are threatened by ranches, deforestation, and coffee plantations, among other factors.

Douglas-fir (Pseudotsuga menziesii)
Old-growth Douglas-fir averages 250 feet in height and 4 to 8 feet in diameter (one reaching 385 feet tall and 15 feet wide was reported). Highly adaptable, Douglas-fir can prosper under a wide range of climatic conditions and is the dominant species in Pacific Northwest forests. It grows from central British Columbia southward in the coastal states to central California and extends down the Rockies through Arizona and New Mexico into the high mountains of subtropical Mexico. In California, it flourishes in the wet, North Coastal forests, yet it also thrives in the Sierra Nevada mixed-conifer forests with their intense summer drought. Although Douglas-fir has one of the widest ranges of any North American conifer, low-elevation fir and mixed evergreen forests have been exploited heavily.

Douglas-fir species are found in China, Japan, and Taiwan. The tree was introduced from the Pacific Northwest to Chile, where it's known familiarly as Pino Oregono, or Oregon Pine—which is a misnomer, just as “fir” is in its English name. Douglas-fir is not a true fir. This name game is confused even further by Pseudotsuga, which means false hemlock. The tree is not a fir, a hemlock, or a pine, but rather its own distinct genus. Like pines and spruces, Douglas-firs have resinous wood, which is used in laminates, lumber, plywood, furniture, and shipbuilding—leading to its desirability and overcutting.

Mangrove
Mangrove forests live in the harsh and unpredictable interface between land and sea. They are composed of taxonomically diverse, salt-tolerant tree and other plant species and they provide critical habitat for marine and terrestial life. Mangroves have specially adapted aerial and salt-filtering roots and salt-excreting leaves that enable them to occupy the saline wetlands where other plant life cannot survive; they thrive in inter-tidal zones of sheltered tropical shores, "overwash" islands, and estuaries.

The mangrove forest litter, consisting mainly of fallen leaves and branches, provides nutrients for the marine environment and supports immense varieties of sea life in intricate food webs. Their shallow intertidal reaches offer refuge and nursery grounds for juvenile fish, crabs, shrimps, and mollusks.
Mangrove forests are also prime nesting and migratory sites for hundreds of bird species. In Belize, more than 500 species of birds have been recorded in mangrove areas. Additionally, manatees, crab-eating monkeys, fishing cats, monitor lizards, sea turtles, and mud-skipper fish utilize mangrove wetlands. Mangroves are also useful in treating effluent, as the plants absorb excess nitrates and phosphates, thereby preventing contamination of nearshore waters.

These complex ecosystems are found between the latitudes of 32 degrees north and 38 degrees south, along the tropical coasts of Africa, the Americas, Asia, and Australia. Mangroves vary in height according to species and environment, from mere shrubs to 120-foot trees. (The newly founded Majagual reserve in Ecuador's Esmeraldas province contains the tallest known mangrove tree in the world).

Mangrove ecosystems have been exploited heavily by local populations for the production of tannins, fuel wood, and construction materials. But most of the damage has occurred since the advent of shrimp farming; this highly volatile enterprise has grown exponentially over the last 15 years. As much as 50% of mangrove destruction in recent years is attributed to clearcutting for shrimp farms. Industrial shrimp farmers remove mangroves and divert freshwater sources to create ponds where saltwater is pumped onto the land, permanently altering the soil's composition, PH, and salinity. In regions where these coastal fringe forests have been cleared, erosion and siltation occur. The exposed portions of mangrove roots are highly susceptible to clogging by crude oil and other pollutants, attacks by parasites, and prolonged flooding from artificial dikes or causeways.

Redwood (Sequoia Sempervirens)
California's coast redwood tree continues to inspire admiration in all who behold its splendor. This conifer flourishes along the Pacific coast in a fog-belt about 450 miles long and 5 to 25 miles wide, almost entirely in California (from southwestern Oregon to Monterey County). It is not nearly as adaptable as Douglas-fir—it is unable to withstand frost when young or to survive without fog and heavy rainfall. Only a small portion of the few remaining redwood expanses are protected. Sequoia sempervirens is related to the massive Sequoiadendron giganteum, or giant sequioa, which inhabits the Sierra Nevada and reaches diameters of 30 feet but doesn't grow as tall as the coast redwood.

The redwood, the world's tallest confirmed tree, has been reported at 368 feet in height (commonly reaching 300 feet) and 16 feet in diameter. It is renowned for longevity—the oldest recorded age is 2,200 years. The younger trees have a rich, reddish brown bark (derived from a high amount of tannin), while the older are more gray/brown; this bark protects the tree against fires and pests. The trunk can be a column with no limbs for the first 100 feet or more. The redwood tree can regenerate itself through cloning as well as by seed; “fairy rings” sprout around the parent tree when it dies.

In addition to being so impressive in its size, beauty, and ecological importance, the redwood is useful as a building material, like the alerce, and therefore attractive to the logging industry. Moreover, the coast redwood's proximity to rivers and the ocean has made it desirable since heavy logging began, and the prodigious yield from a single forest acre—125,000 to 150,000 board feet on the low end—has ensured that its constant attack.

Southern Beech (Nothofagus spp.)
This common hardwood tree covers vast territories in the world's southern regions. The Nothofagus species found in Chile and Argentina include the endangered ruil (N. alessandri), roble (N. obliqua), raul’ (N. alpina), lenga (N. pumilio), hualo (N. glauca), coihue (N. dombeyi), Magellanic coihue (N. betuloides), and nirre (N. antarctica).

One widespread southern beech tree, the lenga, often grows in heavy snowpack areas above the true forest. It ranges from the high Andes at 37 degrees south to sea level near Tierra del Fuego at 56 degrees south. The lenga's fast-growing, cherry-colored wood is naturally resistant to decay, is a high enough quality for exterior and interior use, and is targeted as a major new source for wood chips -these are all serious threats to its survival, especially in southern Chile, where its growth is slower and the rate of exploitation most out of control. On the best sites, lenga trees grow 120 feet in height and 3 feet in diameter.

The coihue is the dominant southern beech in much of the Bosque Valdiviano (Valdivian Forest). It is much larger than the lenga, and because it is a good lumber species, it too is severely threatened. Other threatened hardwoods include the ulmo (a great honey tree) and the laurel (a large hardwood with sassafras-scented leaves).

Tropical and Temperate Rainforests
Rainforests are old-growth forests located in tropical regions near the equator and a few temperate regions that receive comparable rainfall. They are central to the ecological integrity of the planet and the equilibrium of its climate. Rainforests cover 6% of its land mass, yet they house more than half the plant and animal species.

They originally covered at least twice that area. Rainforests are being destroyed at a staggering rate. According to the National Academy of Science, at least 50 million acres a year are lost, an area the size of England, Wales, and Scotland combined.

Tropical rainforests, characteristic of the Ecuadorian Amazon, are defined primarily by two factors: location (in the tropics) and amount of rainfall (from 13 to 26 feet a year). The heavy vegetation in tropical rainforests blocks rainfall, and water reaches the forest floor by rolling down branches and trunks or falling in a fine spray. Another distinctive characteristic is that they have no 'seasonality' - no dry or cold season of slower growth. Tropical rainforests are the Earth's oldest living ecosystems - surviving 70 to 100 million years in more or less their present form. The Amazon is the world's largest, containing some 40% of the remaining tropical forest and a fifth or sixth of the world's fresh water.

Characterized by heavy rainfall, few fires, and a mild climate, coastal temperate rainforests connect the mountains with the sea. These forest ecosystems have developed in the cool, wet climate stirred by marine influences and the Humboldt currents of the Pacific Ocean. At 40 degrees latitude north and south, trees don't expend all their energy in heat loss (as they do in the tropical rainforest), so they can reach greater size and far more biomass per acre than do tropical rainforests. Temperate rainforests stretch 1,200 miles from Oregon to Alaska. Smaller temperate rainforests can be found on the southeast coast of Chile, Southern Australia, southern New Zealand, Norway, the United Kingdom, and Japan.

From: http://www.ancientforests.org/forest_types.html