Question

Introduction TO ECOLOGY

Define ecology and state in one sentence, its importance for understanding the environment.

List biotic and abiotic factors that determine the distribution of organisms on Earth.

List ten of Earth’s major terrestrial and/or aquatic biomes and list characteristics of each.

Identify two factors that dictate the distribution of all terrestrial biomes and explain the importance of each in one sentence.

Answer 1

Ecology is the branch of biology which deals with the relationships and interactions of living organisms, among them and with the environment. Ecology depicts how the organism interact with its habitat.

The biotic and abiotic factors affect the distribution of organisms. Biotic factors include the interactions by the living things in an ecosystem. This can include grazing and predation. Animals which graze on the plant species in an ecosystem can influence survival of the plant species. Similarly, animal species which predate on other animal species can influence the survival of the latter in a particular ecosystem. Human activityincreasingly affect the diversity of an ecosystem.

Abiotic factors are the non-living factors in an ecosystem such as temperature, pH or moisture levels. Extremes of an abiotic factor can reduce the biodiversity of the ecosystem. For example, ecosystems with a very low temperature tend to have low biodiversity.

A biome is a major, geographically extensive ecosystem, structurally characterized by its dominant life forms.

Terrestrial biomes:

1. Tundra is a treeless biome occurring in areas with cold climates and a short growing season.

2. The boreal coniferous forest or taiga, is dominated by coniferous trees, It is an extensive biome in north and occurring in moist climates with cold winters.

3. Temperate deciduous forests are dominated by species-rich mixtures of broad-leaved trees occurring in moist temperate climates.

4. temperate rainforest is characterized by mild winters and an abundance of precipitation.

5. Grasslands occur under climatec regimes that is intermediate to those that support forest and desert. Prairie in north America is an example.

6. Savannas are characterized by grasses and other herbaceous plants, scattered shrub and tree-sized woody plants, which form a very open canopy.

7. Desert form where water availability is less and precipitation is less than 9.9in (25cm).

8. Lotic biome: The character of this running-water biome is determined by physical factors, especially the quantity, velocity, and seasonal variations of water flow. The common lotic ecosystems include rivers, streams, and brooks.

9. Freshwater wetlands occur in shallow waters usually having pronounced seasonal variations of water depth.

10. The character of the open-water, or pelagic oceanic biome is determined by physical and chemical environmental factors, particularly waves, tides, currents, salinity, temperature, light intensity, and nutrient concentration.