All about Rainforest Biome

The Temperate Rainforest

Temperate rainforests are coniferous or broadleaf forests that occur in the temperate zone and receive high rainfall. Temperate rain forests are found on the western edge of North and South America, where moist air from the Pacific Ocean drops between 60 and 200 inches of rain a year. Unlike the tropical rain forest, the temporate rain forest has seasonal varition, with summer temperatures rising to about 80 degrees Fahrenheit and winter temperatures dropping to near freezing. In the northernmost regions, winter may be cold enough for some ice and snow.

            Although this rain forest has layers of tall, medium, and low growing vegetation, the cool winters limit the numbers and kinds of life forms that live here. Compared to the tropical rain forest, the temperate rain forest has a less complex ecology. For example, the topmost layer of the temperate rain forest on the western edge of North America is dominated by four kinds of tall coniferous trees. These are: Small shade-loving trees, such as dogwoods and vine maples, form the understory level. Beneath the trees, shrubs such as wild currants, thimbleberries, and huckleberries grow in the filtered sunlight. Sword ferns, salal, and Oregan grape plants also thrive here.

At the ground level, the earth is littered with dead fir needles, leaves, twigs, and fallen trees. These lie on and under a thick carpet of mosses, lichens, grasses, and small plants, such as Oregon oxalis (which has leaves like a shamrock). The rocks are green with moss, and the tree trunks and branches are covered with moss and algae. These low-growing plants are shade tolerant. Here and there one may find toadstools, mushrooms, and other kinds of fungi: these saprophites (organisms that digest dead organic matter) help to recycle the dead material on the forest floor.

This forest has nutrient-rich soil because there is a lot of dead organic matter on the ground. This dead material is being slowly digested by the fungi, insects, and bacteria that live here. In the tropical forests the trees have to spend some of their energy drawing up water and getting rid of heat: in this milder climate the trees can grow and grow.

             Scientists say that there is more biomass in this biome than in any other biome on earth. There may be 500 tons of living things per acre here! That translates down to about 206 pounds per square yard, about the same as one good sized human adult per square yard!

             Most of the animals in this forest live on or near the ground, where there is lots of food, and the trees provide shelter from sun, wind, and rain. Beetles burrow in the moss and hide in the bark of trees. Wood peckers and birds eat the insects. Grass is eaten by the voles (cute little mouse-like animals) and the deer.

            There is food that is easier to eat than the tough needles of the conifers. However, the conifers do provide food when they make their nourishing seeds. Birds and small animals eat these seeds.

Climate:

             













 The obvious element of climate in the temperate rain forest is precipitation.  At least 200 cmaverage annual temperature is above 0� C, largely influenced by the nearby ocean.  The warmest of the temperate rainforests may have average annual temperatures around 20� C. of it, perhaps up to 350 centimeters in warmer areas.  The precipitation can fall in the form of rain or snow, with snow becoming more likely at higher elevations.  The

 

 

 

 

 

 

World Distribution:  

This is a small biome in terms of area covered.  The main stretch of this habitat is along the northwestern coast of North America from northern California though southern Alaska.  There are also small areas in southern Chile, New Zealand, Australia and a few other places around the world, most of which don't show up on the scale of the map to the right.  In general, such forests form were relatively warm offshore waters affect inland climates.

 

Indicator Plant Species:

 

 

Big coniferous trees dominate this habitat, including Douglas fir and Western red cedar, Mountain hemlock, Western hemlock, Sitka spruce and Lodgepole pine.  In addition, a number of deciduous trees are found here, particularly in warmer spots.  One of these is Big-Leaf Maple.
 

In addition to the trees, mosses and lichens are very common, often growing as epiphytes.  Epiphytes are also common in tropical rain forests; the common denominator is the moist environment

that puts minimal water stress on plants without roots.     
            

In the pictures here you can see Douglas Firs in the photo above.  The photo above right shows a ground-level view of the mossy forest floor, while the two lower photos to the right illustrate the epiphytes - mosses and lichens - that make a southern temperate rainforest home (note the deciduous trees).  Below is a species of Indian Paintbrush growing in a temperate rainforest in British Columbia.

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While mammals are certainly found in this biome, we have seen many of them (deer, bears, coyotes, etc.) in other biomes.  I thought I'd focus on a few other species here. You can't go to the Pacific Northwest without encountering a diversity of slugs.  These shell less gastropods are very much at home here; the humid air prevents desiccation (although I well remember encountering banana slugs on early morning jogs in Los Angeles; they are able to live in that desert city thanks to well-watered lawns).  The longer of the antennae have eyes at the ends of the stalks and the slug itself secretes a trail of slime (not unlike some po - wait, I'm not going to stoop to that joke here, it's too easy). The slime helps it crawl and protects the soft underside from sharp objects.

By: Jared June Casabuena