Woody plants: parts and classification
A woody plant has stems that get thicker each year because of wood. Three kinds: trees (one tall trunk, usually above 5 m), shrubs (many stems from the base, below 5 m) and woody climbers (like vines). A tree has a crown (branches and leaves), a trunk (bark, wood, pith) and roots. Inside the trunk the thin cambium makes a new ring of wood each year. Foresters classify woody plants by leaf type (needle or flat), by how they reproduce (cones or flowers) and by whether they are evergreen or deciduous.
Forest tree species: conifers and broadleaf trees
Gymnosperms (conifers) have naked seeds in cones and needle-like leaves. Examples: spruce, fir, pine, larch. Most are evergreen and have soft wood (softwood). Angiosperms (broadleaf trees) have flowers and seeds inside fruits, with flat leaves. Examples: oak, beech, hornbeam, maple, birch. Most are deciduous and have hard wood (hardwood), although some, like balsa, are soft. In the tropics most forest trees are broadleaf evergreens, such as teak and sal.
Ecology and range of forest species
Each species has a range: the area where its needs for light, warmth, water and soil are met. Temperature falls about 0.65 °C for every 100 m of height, so a mountain has altitude zones: lowland broadleaf forests, a middle mixed belt, and conifer forests on the cold slopes, then meadows and bare rock. Some species like shade (beech, fir), others need strong light (pine, birch, larch). Pioneer species arrive first on bare ground; climax species take over in the end.
Soil: formation, properties, profile and types
Formation. Rock is broken by weather (weathering). Plants, animals and tiny life add dead matter that rots into humus. Water carries minerals downwards. This takes hundreds to thousands of years.
Properties. Texture (the share of sand, silt and clay), structure (crumbs or blocks), water holding, acidity (pH) and fertility.
Profile. O: litter and humus on top. A: dark topsoil mixed with humus. B: subsoil where minerals collect. C: weathered rock. R: solid bedrock. Together these layers are the soil profile.
Types. Forest soils include brown forest soils under broadleaf trees (rich and crumbly), podzols under conifers (acid, with a pale leached layer), and mountain soils (thin, stony).
Atmosphere, weather elements and instruments
The atmosphere is the layer of air around the Earth. Weather elements are temperature, air pressure, humidity, wind, clouds and rainfall. Instruments: thermometer (temperature, kept in a shaded screen), barometer (air pressure), hygrometer (humidity), anemometer and wind vane (wind speed and direction), rain gauge (rainfall in mm). Forests are cooler, more humid and less windy inside than in the open, and this is called the forest microclimate.
Non-timber products: food, chemicals and industry
Forests give food (wild berries, mushrooms, nuts), medicinal plants, resin (turpentine and rosin from pines), tannin (from oak bark, for leather), cork, bamboo and rattan, Christmas trees and craft materials. Collect only what is allowed, in the right season, and leave enough so the plants can regrow.
Bees and bee products
Honey bees live in colonies of a queen, workers and drones. Workers collect nectar and pollen and carry it to the hive. They also pollinate the flowers, which helps forests and farms. Products: honey, beeswax, pollen, propolis (a sticky resin used to seal the hive) and royal jelly. Beekeepers place hives near flowering trees, such as acacia and linden, and move them to follow the bloom.
Game species, management and mountain-water fauna
Game species are wild animals that may be hunted under law, such as deer, wild boar, hare and some birds. Game management keeps numbers healthy: count the animals, set a yearly quota, provide feed and water in hard winters, and control predators and disease. Hunting rules include licences, closed seasons when animals breed, banned methods and protected species. Mountain waters hold cold-water fish such as trout, which need clean, oxygen-rich water, and animals like the otter and the water insects they feed on.
Try it: climb the mountain
In the 3D, last step, move the Altitude slider. Write down the temperature at 0, 1,000 and 2,000 m. Check with the rule: fall = 0.65 × (height ÷ 100). At home, make a simple rain gauge from a straight-sided bottle and a ruler, and measure rainfall in mm after a shower.
Key formulas and definitions
- Temperature at height h = sea-level temperature − 0.65 × (h ÷ 100) (°C, h in m)
- Stand density = number of trees ÷ area (trees per hectare)
- Sustainable cut ≤ yearly growth × area
- Soil profile (top to bottom): O, A, B, C, R
Worked examples
1. A valley at sea level has 15 °C. What is the temperature at 1,300 m?
Fall = 0.65 × 13 = 8.45 °C. Temperature = 15 − 8.45 = 6.55 °C.
2. There are 600 trees on 2 hectares. What is the density?
600 ÷ 2 = 300 trees per hectare.
3. A forest grows 4 m³ of wood per hectare per year. How much may be cut each year from 50 ha without shrinking the forest?
4 × 50 = 200 m³ per year at most.
4. Name the soil layer where dead leaves rot into humus, and the layer of solid rock.
Dead leaves are in horizon O (litter and humus on top). Solid rock is R (bedrock), under the C layer.
Common mistakes
- Thinking all conifers are evergreen. Larch is a conifer that drops its needles in autumn.
- Mixing up the soil layers. The order from the top is O, A, B, C, then bedrock.
- Believing a bigger hive always means more honey. It depends on flowers, weather and care.
- Hunting or collecting without checking the season and quota. Rules protect breeding animals and plants.