autotrophic
An organism capable of producing its own energy. E.g. green plants.

bacteria
Primitive prokaryotic organisms.

biosphere
The part of planet Earth that is capable of accommodating life.

brumation
An overwintering strategy used by many poikilothermic animals, in which the animal's vital functions cease almost completely.

chlorophyll
The green pigment found in chloroplasts of the plant cells. Chlorophyll absorbs sunlight and makes photosynthesis possible. It also gives plant leaves their distinctive green color.

consumer
An organism that gains its energy by eating other organisms.

decomposer
An organism that gains energy by dismantling parts of dead organisms.

diversity
The number of different species and types of organisms, species, and ecosystems found in a certain area.

dry taiga forest
A pine forest. The soil of a dry taiga forest consists of either sand or gravel and is low in nutrients.

ecological niche
An ecological niche is comprised of the resources used by a certain species. These resources include e.g. the food that the species eats and the area the species inhabits.

ecosystem
An ecosystem comprises of the abiotic (non-living) environment and the living organisms that inhabit this environment.

endangered species
A species that is in danger of becoming extinct.

eukaryotes
Protists, plants, animals, fungi. Organisms that have nuclei and specialized organelles in their cells.

evolution
The gradual development of species as a result of mutations and natural selection.

extinction
A phenomenon in which a species disappears completely or becomes extinct

fell summit
The bare, treeless top of a fell.

fern
A group of spore-producing plants or pteridophytes.

field layer
The layer of vegetation consisting of plants below 0,5 m in height. E.g. sprigs and grasses.

Finnish everyman's rights
A set of rights belonging to all Finnish citizens.

food chain
A chain that comprises of the species of an organism community. Begins at the level of the producer (plant) and ends at the level of the high-degree consumer.

food web
A food web is comprised by the interconnected food chains of a certain community.

fruit body
A spore-producing fungal structure. Usually the visible "mushroom" of the fungus.

ground layer
The lowest layer of vegetation on the forest floor. Consists mostly of mosses and lichens.

grove
A type of a broadleaf forest, the soil of which is high in nutrients.

growing season
The time of the year when the air temperature stays above +5 degrees Celsius. Plants grow and reproduce during the growing season.

heterotrophic
An organism that gains its energy by eating or decomposing other organisms.

hibernation
An overwintering strategy used by some mammals, in which the animal's body temperature drops just above zero degrees Celsius.

homeothermic
An animal that is capable of regulating its body temperature.

hypothesis
A presumption that can be tested with scientific means. For example, the statement "increased nitrogen results in more plants in a lake" is a hypothesis.

lichen
A symbiotic organism that consists of a fungal and an algal part.

metamorphosis
A process through which an organism develops into an adult through various different stages.

migrating bird
A bird species that spends its winter in a different location from its nesting region.

mixed forest
A forest that consist of various tree species of relatively similar prominence.

mutation
A change in an individual's genome (DNA molecule).

mycorrhiza
The symbiotic structure that forms as a combination of a fungus mycelia and a plant root.

natural selection
A phenomenon where the fittest individuals reproduce most effectively.

nucleus
The part of the cell that contains the cell's genome in its chromosomes. 

nutrient
A substance needed by an organism to grow. For example, nitrogen and phosphorous.

park
A cultivated green area in a town or a city.

peat
A soil type common to bogs. Peat is formed as the result of the slow decomposition of plant matter in anaerobic conditions.

pollination
The transportation of a plant's pollen to another plant's pistil via birds, insects, water, or wind.

population
A group of individuals of the same species that inhabits the same area.

predator-prey relationship
A relationship between two species where the predator species benefits at the expense of the prey species.

producer
A plant or bacteria that produces energy via photosynthesis.

producer
An organism that creates chemical energy through photosynthesis.

sedentary bird
A bird species that spends all the seasons in the same region.

seed plant
A plant that produces seeds.

sexual reproduction
Reproduction that takes place with the help of sex cells or gametes (sperm cells and egg cells).

site factors
The environmental conditions (heat, light, water, nutrients, soil) that influence plant growth.

soil
The loose ground above bedrock.

spawning
The reproductive method of fish.

spore
A reproductive cell used by fungi and spore-producing plants such as mosses and ferns.

sprig
A woody plant under 0,5 meters tall.

spruce bog
A forest-like bog type where spruce is the dominant tree species.

succession
The change in forest vegetation that occurs in stages over time. 

symbiosis
A mutually beneficial relationship between two species.

tundra
A treeless biome of the frigid zone.

urban forests
Forested areas located near towns and cities.

vascular tissue
The cells that conduct water and nutrients between the leaves and roots of a plant. 

wet taiga forest
A spruce forest. The soil of a wet taiga forest consists of nutrient-rich till.

winter sleep
An overwintering strategy found in some mammals, in which the animal's body temperature drops by a few degrees and its vital functions slow down.