Ecosystem

Question 1

Litter

Answer 1

Surface layer of vegetation which may eventually become humus.

Question 2

Biomass

Answer 2

Total mass of living organisms per unit area.

Question 3

Law of Minimum

Answer 3

(by Carl Sprengel & Justus von Liebig) Liebig’s law of the minimum states that growth is controlled not by the total amount of resources available, but by the scarcest resource (limiting factor).

Question 4

Law of maximum

Answer 4

(by Arthur Wallace) Law of maximum states that total growth of an organism is proportional to about 70 growth factors.

Question 5

Holocoenotic environment

Answer 5

A German ecologist Karl Friederich (1927) suggested that ‘community-environmental relationship are holocoenotic’. This means that there are no ‘walls’ or barriers between the factors of an environment and the organism or biotic community.

Question 6

Relative humidity

Answer 6

Relative humidity is the amount of moisture in the air compared to what the air can “hold” at that temperature.

Question 7

Summit

Answer 7

A summit is a point on a surface that is higher in elevation than all points immediately adjacent to it.

Question 8

Saprotrophic organisms

Answer 8

Set of organisms that feed on dead and decaying organic matter, known as saprotrophic organisms, function as decomposers.

Question 9

Rhizosphere

Answer 9

The zone in the soil influenced by roots is called the rhizosphere. It extends a few millimeters from the surfaces of living roots.

Question 10

Macroflora

Answer 10

Higher plants, including crop plants, are termed macro flora. The root systems of such plants normally proliferate throughout the upper horizons of the soil profile.

Question 11

Microflora

Answer 11

Microscopic plants such as algae and cyanobacteria are classed as microflora. They are photosynthetic organisms, mostly active at or near the soil surface.

Question 12

Hyphae

Answer 12

Some of the fungi produce long chains of cells called hyphae, and these interweave to form branching filaments also known as mycelia that - though only a few micrometers in width - may extend many centimeters or even meters in length.

Question 13

Micro fauna

Answer 13

Fauna that are less than 1 mm in size are known as micro fauna. They are represented in the soil by numerous morphologically diverse groups.

Question 14

Macro fauna

Answer 14

Macro fauna in the soil also include large invertebrates such as earthworms, termites, ants, millipedes, centipedes, spiders, beetles, and mites.

Question 15

Crotovinas

Answer 15

Tunnels dug into the soil profile by such burrowing animals as gophers and often filled with soil from different horizons are called crotovinas.

Question 16

Nitrogen fixation

Answer 16

Nitrogen fixation is the absorption of elemental nitrogen from the atmosphere (N2) and its incorporation in organic compounds of living organisms.

Question 17

Ammonification

Answer 17

Ammonification is the formation of ammonium (NH3 and the ion NH4+) from nitrogen-containing organic compounds such as amines (-NH2).

Question 18

Nitrification

Answer 18

Nitrification is the oxidation of ammonium to nitrite (N02-) and nitrate (NO3-).

Question 19

Denitrification

Answer 19

Denitrification is the reduction of nitrogen oxides back to the elemental form.