Because rapid bacterial decay prevents the accumulation of humus. 6. How do the soils in tropical deciduous forest differ from the soils in tropical rainforest? The soil in tdf has more nutrients, because the leaves fall down and trees grow more sparsely. 7. Describe the layers of tropical rainforest. Emergents forest giants, the trees there are 50m or more. Canopy a dence layer, the trees there are 20-30m. There can be found many hardwoods, such as mahagony. Understory a dark and a humid area, contains saplings between the trunks of larger trees. 8. How does the vegetation in tropical deciduous forest differ from the vegetation in tropical rainforest? Trf has more kinds of trees than tdc. About 70% of the plants in trf are trees. 9. Using the picture (given in the test) describe how a plant is adapted to the life in tropical rainforest? Epiphytes, liana, climbers or stranglers. 10. What is an epiphyte
of their rainforests. But despite the levels of deforestation, up to 60 percent of their territory is still covered by natural tropical forests. In fact, today, much of the pressures on their remaining rainforests comes from servicing the needs and markets for wood products in industrialized countries that have already depleted their own natural resources. Industrial countries would not be buying rainforest hardwoods and timber had we not cut down our own trees long ago, nor would poachers in the Amazon jungle be slaughtering jaguar, ocelot, caiman, and otter if we did not provide lucrative markets for their skins in Berlin, Paris, and Tokyo.
inches. This precipitation falls throughout the year, but in the winter it falls as snow. There are four seasons in this biome, with warm summers and cold winters, often snowy. In autumn, the leaves change color and fall from the trees. The leaves decay on the forest floor, so the soil is very rich. Because of this, and because of the long growing season, many deciduous forests have been cut down for farming purposes. Plants: Trees of this biome include hardwoods such as maple, oak, hickory, and beech. There are often some evergreens, such as hemlock, spruce, and fir growing amongst them. Decidous forests have usually 3-5 layers of plants; Top layer, or canopy: tall deciduous trees. Although the canopy is quite thick, it does allow sunlight to reach the forest floor, which encourages the other layers to grow. The 2nd layer: saplings and shorter kinds of trees The 3rd layer, or understorey: shrubs.
viimistleda ning puu ei ole ohustatud liikide nimistus. Põnev oli teada saada, et mustast pähklipuust saab valmistada nii palju erinevaid asju, alustades kellakorpustest ja lennuki propelleritest ning lõpetades mööbli ja parketiga. Väga huvitav oli fakt, et mitte ainult puitu, vaid ka pähklikoori kasutatakse toormaterjalina laialdaselt. Kasutatud allikad: http://www.hardwoodinfo.com/articles/view/pro/24/320 http://www.wood-database.com/lumber-identification/hardwoods/black-walnut/ http://www.vaarispuu.ee/puuliigid/1-puuliigid/14-ameerika-paehkel.html http://et.wikipedia.org/wiki/P%C3%A4hklipuu http://www.mass.ee/ameerika-pahkel http://forestry.about.com/library/silvics/blsiljugnig.htm http://www.woodsolutions.com.au/Wood-Species/American-black-walnut http://www.extension.umn.edu/garden/yard-garden/trees-shrubs/growing-black-walnut/
vedelproduktide aurud ja raske jääk on asphalt, mis sisaldab polüaromaatikat. Viimane krakitakse rohkem lenduvateks CH-deks ja koksiks: C42H56 = 2C8H18 + C4H10 + C2H6 + C2H4 + 18C Asfalteen oktaan butaan etaan etyleen koks 9. Puit koostis, omadused Puidu tehnoloogias jagatakse puitu kahte gruppi: 1)pehme puit (softwoods) = okaspuud (vaigurikkad): kuusk, mänd, kanada must kuusk, siberi kuusk, lehis jt. kõva puit 2)(hardwoods) = lehtpuud: kask, vaher, lepp, haab, tamm jt. Puidu tahkest osast on > 95% orgaanika: 1)Tselluloos [C6H7O2(OH)3]m - ~ 45% kuivkaalust 2)Hemitselluloos [C6H7O2(OH)3]n - ~ 20-30% ; n < m 3)Ligniin ~ (20-30%) 4)Ekstraktiivained - ~ (3-10%) 5)Mineraalid Tselluloos: kiulise ehitusega, n.ö puidu ,,skelett", kõrgmolekulaarne polüsahhariid, M= 50000-150000, annab puidule tugevuse ja elastsuse. Tselluloos on tegelikult glükoosi polümeer. Glükoos tekib rohelistes
osaleb USA rahastatud kampaanias, marihuaana kauplemise likvideerimiseks. Jamaica riigis on vist vahepeal arutadud ka seda, et kanep legaliseerida, kuid siiamaani ei ole seda veel tehtud. Pilt: Kanepi leht. Kalandus ja metsandus Looduslikud metsad, maa millel kasvas vähemalt 21% ulatuses metsa, moodustas 24 protsenti kogu maaalast. Valitsuse metsa reservid olid suured. Kui 1980-ndate aastate lõpus, kuid omavarustatust oli veel kaugel. Pikaajalise arengu peamiselt hardwoods, mänd ja teiste liikide oli kavas toetada mööbli-, käsitöö- ja ehitamise konkurentsivõimet. Väikesed saeveskid olid olemas kui ei olnud kunagi piisavalt varusid. Hiliste 1980-ndate aastate lõpuks oli vaid 185000 hektarit (457000 aakri) alles jäänud Jamaica algsest metsast (1000000 hektarist ehk 2500000 aakrist). Ümarpuidu toodang suurenes 55000 cu m (1,9 miljonit cu jalga) 1981 220000 cu m (7,8 miljonit cu jalga) aastal 1988 ja 881000 cu m (31,1 miljonit cu jalga) 2000. Umbes 68%
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