RSS Feeds

Earth Science

Space Science

Life Science

Fields of Scientific Study

Nanotechnology

Cancer

Definitions of The Fields of Scientific Study

Without disturbances in nature the world's forests will be impoverished

June 21, 2004

The forests of the world are not the stable and unchanging ecosystems they have been assumed to be. Without the occurrence of wide-spread disturbances in nature, such as forest fires, icing, or volcanic activity, forests will eventually be impoverished, owing to a lack of phosphorous.

This is shown in a study reported in this week's issue of the journal Science. The scientists who carried out the investigation are David Wardle, Department of Forest Vegetation Ecology, Swedish University of Agricultural Sciences (SLU), Sweden, Richard Bardgett, University of Lancaster, U.K., and Lawrence Walker, University of Nevada, U.S.

The three researchers have examined soil profiles from forested land in six places around the world: in Arjeplog in Swedish Lapland, Alaska, Hawaii, Eastern Australia, and southern New Zealand (two locations). In all places there are soils of extremely varying age, from very young to several thousand years old. The oldest soil, in Hawaii, was 4.1 million years old.

In all six locations forests grew least well in the oldest soils, because the access to absorbable phosphorous was limited in comparison with access to absorbable nitrogen. When soils age, less phosphorous becomes available to trees, since phosphorous is not biologically replenished in the soil or supplied to the ecosystem in any other way. Nitrogen, on the other hand, is renewable; atmospheric nitrogen is continuously supplied to the soil and is tranformed by soil bacteria to forms of nitrogen that the trees can take up. It is not a lack of nitrogen, as has previously been thought, but a lack of phosporous that lies behind poor growth in forests when they become old.

The shortage of phosphorous in the older soils also influenced the soil organisms in a negative manner, reducing their ability to release soils nutrients. The scientists draw several conclusions from their findings. First of all, they show that greater disturbances are necessary if we wish to renew forest ecosystems. What type of disturbances are required varies with soil type, but forest fires, icing, or volcanic activity can be mentioned. If such disturbances do not occur, forests cannot be endlessly renewed. Ultimately the lack of phosphorous will become such a hindrance that the soil will no longer be able to provide sufficient nourishment for densely planted forests with large trees.

A second conclusion is that productive forests are temporary, seen from the perspective of a thousand or ten thousand years: if no disturbances occur in nature, then such forests will slowly be impoverished. The patterns for how this impoverishment takes place, and its underlying mechanisms, are the same, regardless of what type of forest it is and where it is located on earth. The same processes occur in boreal, temperate, and tropical climates, albeit at different rates.

VetenskapsrÃ�det (The Swedish Research Council)

Science Research Departments

	Scientific Explorer's Mind Blowing Science Kit for Young Scientists by Scientific Explorer Mind blowing experiments to delight and educate young scientists! Erupt a color changing volcano. Mix up magic ooze with a mind of its own. Play with sand that never gets wet. Mix safe chemicals and watch colors change before your eyes. You'll amaze yourself and your friends as you explore the science behind these truly remarkable reactions.
	The Everything Kids' Science Experiments Book: Boil Ice, Float Water, Measure Gravity-Challenge the World Around You! (Everything Kids Series) by Tom Robinson (Author) Science has never been so easy - or so much fun! With The Everything Kids' Science Experiments Book, all you need to do is gather a few household items and you can recreate dozens of mind-blowing, kid-tested science experiments. High school science teach Tom Robinson shows you how to expand your scientific horizons - from biology to chemistry to physics to outer space. You'll discover answers to questions like: Is it possible to blow up a balloon without actually blowing into it? What is inside coins? Can a magnet ever be "turned off"? Do toilets always flush in the same direction? Can a swimming pool be cleaned with just the breath of one person? Get ready to enter the laboratory and learn how to conduct cool experiments, understand scientific terms...
	Scientific Explorer's Disgusting Science - A Kit for Studying the Science of Revolting Things by Scientific Explorer Grow your own friendly germs and fuzzy molds. Mix up a batch of coagulating fake blood. Even make a stinky intestine. learn the science behind unmentionable bodily functions while doing some truly NASTY Experiments. Ages 8+
	The Science Book: Everything You Need to Know About the World and How It Works (National Geographic) by National Geographic (Author), Marshall Brain (Foreword) A delight for the casual reader, yet so complete and wide-ranging that science buffs and students will welcome it, The Science Book encapsulates centuries of scientific thought in one richly illustrated volume. Natural phenomena, revolutionary inventions, and the most up-to-date investigations are explained in detailed text, and 2,000 vivid illustrationsincluding 3-D graphics and pictogramsmake the information even more accessible and amazing to discover. The Science Book offers both a general overview of topics for the browsing reader and more specific information for those seeking deeper insight into a particular subject. Six major sections, ranging from the universe and planet Earth to biology, chemistry, physics, and mathematics, encompass everything from microscopic life...
	Scientific Explorer's The Magic Science Wizard's Kit by Scientific Explorer Cast real smoke from your fingertips, make a wizard wand, and whip up color-changing potions in your test tube laboratory. Also included are laminated cards with wizard facts, an instruction booklet with 11 activities, lab equipment, and mysterious wizard powders that will mix together to mystify you!
	Scientific Explorer's Tasty Science Chemistry in the Kitchen Kit by Scientific Explorer Who knew science could taste so good? With this kit, you’ll whip up cupcakes, cookies, candy, and more—all in the name of science! Learn what makes cakes rise, candy crystallize, and more real chemistry happen in the kitchen. Tasty Science is packed with ingredients, recipes, activity cards, a test tube laboratory, and lots more to explore the science of taste.
	The Complete Book of Science, Grades 5-6 by School Specialty Publishing (Author) The Complete Book of Science for grades 5 to 6 teaches children important science skills! Children complete a variety of exercises that help them develop a number of skills in this 352 page workbook. Including a complete answer key this workbook features a user-friendly format perfect for browsing, research, and review. Over 4 million in print! The best-selling Complete Book series offers a full complement of instruction, activities, and information about a single topic or subject area. Containing over 30 titles and encompassing preschool to grade 8 this series helps children succeed in every subject area! ...
	Magic School Bus Journey into the Human Body Science Kit by Young Scientist Club The Magic School Bus and Ms. Frizzle take Young Scientists on a wild ride into the human body with these breathtaking experiments. Young Scientists bend bones, make joints, map taste buds, expand lungs, build a stethoscope, measure lung capacities and heart rates, perform the iodine starch test, spin glitter, simulate synovial fluid, create a human body poster, and much, much more! This exciting kit includes a life-size poster with eight sheets of body part stickers. So put on your seat belts, students, and get ready to discover The Human Body!
	Scientific Explorer's Glow in the Dark Fun Lab Science Kit by Scientific Explorer You will love setting up your own Glow in the Dark Fun Lab. Create a light wand, make your own glow stick, and even generate a human-powered light.
	What Is the World Made Of? All About Solids, Liquids, and Gases (Let's-Read-and-Find-Out Science, Stage 2) by Kathleen Weidner Zoehfeld (Author), Paul Meisel (Author) Did you ever walk through a wall? Drink a glass of blocks? Have you ever played with a lemonade doll, or put on milk for socks? This latest addition to the Let's-Read-and-Find-Out Science series introduces the youngest readers to an important science concept: the differences between solids, liquids, and gases. Any child who wants to know why he can't walk through a wall will enjoy Kathleen Zoehfeld's simple text and Paul Meisel's playful illustrations.