Chapter 1 - What is an Ecosystem? Flashcards Preview

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0
Q

Define Abiotic Environment

A

The physical parts of the environment, as opposed to the biological (biotic) parts.

1
Q

Summarise Chapter 1 - What is an Ecosystem?

A
  • A community is the biological part of an ecosystem, and consists of all the different populations of species living in one place at one time.
  • The systems formed by a community of organisms interacting with one another and their environment is an ecosystem. An ecosystem can be small, such as a pond or aquarium, or large, such as mangrove forests, rain forests or the. Mitchell grass downs.
  • Ecosystems are systems that are largely self-sustaining.
  • A habitat is the place where an organism lives.
  • The environment of an organism is it’s surroundings,both abiotic (non-living) and biotic (living).
  • Niche describes where a species persists and the functional role the organism has in its environment.
  • The physical environmental factors that affect the survival of organisms in freshwater habitats include light, temperature, dissolved gases and nutrients and pH.
  • Soils are an important part of an ecosystem.
  • Halophytes (salt-tolerant species) often have reduces numbers of leaves, few stomata, sunken or protected stomata, hair covering their leaves and thick, waxy cuticle over their leaves. They usually have a higher osmosis pressure in their cytoplasm than other species and may exclude self from leaves, return salt to roots, dilute incoming salt by increased growth, shel salt-laden leaves and/or excrete salt from salt glands.
  • Xenophytes are plants adapted to arid conditions. Adaptations to dryness include reduced leafs surface area; fewer stomata, which are often sunken, a thick cuticle; hairy leaves and the ability to carry out C4 or CAM photosynthesis. Xerophytes may have fleshy leaves and stems for water storage (succulents), a high proportion of woody tissue for support, rapid life cycles (ephemerals), and/or tissues that are able to tolerate almost complete dehydration for months.
2
Q

Define Biotic Environment

A

The biological part of the environment as opposed to the abiotic (physical) parts.

3
Q

Define Cladode

A

A flattened stem that takes on the function of leaves.

4
Q

Define Community

A

All the living organisms in a habitat; the living part of an ecosystem.

5
Q

Define Decomposition

A

The breakdown of complex organic compounds into simpler inorganic substances.

6
Q

Define Ecosystem

A

A system formed by organisms interacting with one another and their physical environment.

7
Q

Define Ephemeral

A

Plant with rapid lifecycle that can be completed in brief periods when water is available.

8
Q

Define Epiphyte

A

A plant that grows on another plant for supports–it is not a parasite.

9
Q

Define Geographic Distribution (range)

A

All the places where a species is found.

10
Q

Define Habitat

A

The place where an organism lives.

11
Q

Define Halophyte

A

A plant that is adapted to salty conditions and which has specialised mechanism for handling excess salt.

12
Q

Define Humus

A

Organic matter formed from the breakdown of dead plants and animals; makes a dark layer in topsoil.

13
Q

Define Intertidal Zone

A

Region (habitat) of rocky sea shore between the high and low tide marks.

14
Q

Define Keystone Species

A

A species on which an ecosystem depends for its survival.

15
Q

Define Lenticel

A

A group of loosely pack cells that allow gas exchange across the otherwise airtight waterproof cork layer covering the stems of plants.

16
Q

Define Liane

A

A woody vine that used trees in forests as a scaffold up which it climbs to reach the light at the top of the canopy.

17
Q

Define Limiting Factor

A

A condition that limits a process, or the abundance and distribution of an organism; for example, shortage of light is an environmental factor that limits photosynthesis and plant growth.

18
Q

Define Microhabitat

A

Small, particular part of a habitat in which particular organisms live, for example beneath the bark of a tree within a forest habitat.

19
Q

Define Niche

A

The role of an organism in an ecosystem, often define by the environmental, biological and other conditions in which it lives. A particular niche, such as a predatory birds may be filled by different animals in different ecosystems (e.g. Wedge-tail eagle in Australia, bald eagle in North America).

20
Q

Define pH

A

A measurement of acidity or alkalinity, measured on a scale of 0 (most acid) to 14 (most alkaline). One unit on the pH scale means a ten-fold difference in acidity or alkalinity.

21
Q

Define Photosynthesis

A

A cellular process in which light energy is trapped by chlorophyll and used to combine carbon dioxide and water to make glucose. The light-dependent stage involves splitting water and producing ATP; the light-independent stage involves the combination of hydrogen and carbon dioxide to make glucose using the ATP produced in the light stage.

22
Q

Define Phyllode

A

A flattened leaf stem that takes on the function of leaf and carries out photosynthesis,

23
Q

Define Population

A

A group of organisms of the same species living in a defined area.

24
Q

Define Ratite

A

Any of the large flightless birds (the emu, kiwi, cassowary, ostrich and rhea) which lack barbules on the feathers and keel on the sternum.

25
Q

Define Salinity

A

The concentration of salt found in water or soil

26
Q

Define Sclerophyll

A

A plant with hard (sclero) leaves (phyll), such as drought resistNt eucalyptus and banksia. Sclerophylls dominate those plant communities which grown on infertile soils, such as heath.

27
Q

Define Succulent

A

A plant that stores water in fleshy stems or leaves.

28
Q

Define Viviparity

A

Giving birth to live young.

29
Q

Define Xerophyte

A

A plant adapted to dry conditions.

30
Q

Define Zonation

A

An arrangement of organisms along a environmental gradient.