|
1. What is a biome?
A biome is a prevailing ecosystem constituted by similar biotic and abiotic factors present in one or more regions of the planet.
2. What are the major terrestrial biomes?
The major terrestrial biomes are: tundra, taigas (or boreal forest), temperate forests, tropical forests, grasslands and deserts.
3. What are the typical vegetation and the typical fauna of the tundra?
Tundra has vegetation formed mainly by mosses and lichens. In the fauna the densely furred animals, like caribous, musk oxen and polar bears, and also migratory birds are found.
Biomes - Image Diversity: tundra
4. What are the typical vegetation and the typical fauna of the taigas?
Taiga, or the boreal forest, is characterized by coniferous trees, pine forests. There are also mosses, lichens, small bushes and angiosperms. In the taiga many mammals, like moose, wolves, foxes and rodents, migratory birds and a great diversity of insects are found.
Biomes - Image Diversity: taigas
5. What are the typical vegetation and the typical fauna of the temperate forests?
In the temperate forest deciduous trees predominate. Mammals are found in great number, like bears and deer.
Biomes - Image Diversity: temperate forests
6. What are deciduous trees?
Deciduous trees are plants that lose their leaves in a period of the year. In the case of the deciduous trees of the temperate forest the fall of the leaves occurs in the autumn (fall). The loss of leaves is a preparation to face the cold months of the winter: roots, stem and branches are more resistant to low temperature and snow than the leaves; without leaves the metabolic rate of the plant is reduced; the decaying fallen leaves help to nourish the soil.
Biomes - Image Diversity: deciduous trees
7. What is the typical localization of the tropical forests regarding latitude?
Tropical rain forests, like the Amazon forest and the Congo forest, are typically located in low latitude, i.e., in the equatorial and tropical zones.
Biomes - Image Diversity: tropical forests
8. What are the typical vegetation and the typical fauna of the tropical forests?
In the vegetation of the tropical forests broadleaf evergreen trees predominate. On the top of the trees epiphytes and lianas grow. Many varieties of pteridophytes can be found in these forests. Regarding the fauna, the abundance and diversity is also great: there are monkeys, rodents, bats, insectivores, felines, reptiles, birds, amphibians and invertebrates, mainly insects.
9. How can the abundance and diversity of living beings in the tropical forests be explained?
The biodiversity of these ecosystems can be explained by the great availability of the main abiotic factors for photosynthesis. Since these factors are abundant plants can perform maximum photosynthetic activity, living and reproducing easily. With a great amount and diversity of producers (autotrophs), the consumers (heterotrophic animals and microorganisms) also have abundant food and a complex food web emerges creating many different ecological niches to be explored. So the appearance of varied living beings as well as the existence of large populations is possible.
10. Why are the tropical forests also known as stratified forests?
In tropical forests tall trees of several species have their crowns forming a superior layer under which diverse other trees and plants develop forming other inferior layers. From the upper layer to the inferior layers the penetration of light lowers gradually and the exposition to wind and rain, the moisture and the temperature also vary. Different compositions of abiotic factors condition the prevailing of different vegetation in each layer.
11. What is the typical vegetation of the grasslands?
Grasslands are mainly formed of herbaceous (nonwoody) vegetation: grass, bushes and small trees.
Biomes - Image Diversity: grasslands
12. What are the grasslands of North America and of South America respectively called?
The steppe grasslands of North America are called prairies. The grasslands of South America are known as “pampas” (the steppe grassland) and “cerrado” (the savannah grassland).
Biomes - Image Diversity: prairies pampas cerrado
13. How are grasslands classified?
Grasslands may be classified into steppes and savannahs. In the steppes the prevailing vegetation is grass, as in the pampas of South America and in the prairies of North America. The fauna is mainly formed by herbivores, like rodents and ungulates. The savannahs present small trees, for example in the Brazilian cerrado or the African savannahs. The fauna is diverse; in the Brazilian cerrado there are animals like ostriches, lizards, armadillos, jaguars, etc., and many types of insects; the African savannahs are the home of large herbivores and carnivores, like zebras, giraffes, antelopes, lions and leopards.
Biomes - Image Diversity: savannah
14. What are the typical vegetation and the typical fauna of the deserts?
The predominant fauna of desert ecosystems is formed by reptiles, like lizards and snakes, terrestrial arthropods and small rodents. In these areas plants very adapted to a dry climate may be found, like the cactus, which are plants that do not have real leaves and thus lose less water, along with grasses and bushes near places where water is available.
Biomes - Image Diversity: deserts
15. Which terrestrial vertebrate group is extremely rare in deserts?
Amphibians are terrestrial vertebrates extremely rare in desert environments (although there are a few species adapted to this type of ecosystem). Amphibians are rare in deserts because they do not have a permeable skin and so they easily lose water by evaporation and desiccate. They also need an aquatic environment to reproduce, since their fecundation is external and their larva is water-dependent.
16. What are plankton, nekton and benthos?
Plankton, nekton and benthos are the three groups into which aquatic living beings may be divided.
The plankton is formed by the algae and small animals that float near the water surface carried by the stream. The nekton is composed of animals that actively swim and dive in water, like fishes, turtles, whales, sharks, etc. The benthos comprises the animals ecologically linked to the bottom, including many echinoderms, benthonic fishes, crustaceans, molluscs, poriferans and annelids.
Biomes - Image Diversity: plankton nekton benthos
17. What are the phytoplankton and the zooplankton?
Phytoplankton and zooplankton are divisions of the plankton. The phytoplankton comprises the autotrophic floating beings: algae and cyanobacteria. The zooplankton is formed by the heterotrophic planktonic beings: protozoans, small crustaceans, cnidarians, larvae, etc.
18. What is the group of aquatic beings composed of a large number of photosynthetic beings?
A large number of photosynthetic beings is found in the plankton, i.e., in the surface of aquatic ecosystems. This is because light is abundant on the surface.
|
