Define Abiotic Environment
The physical parts of the environment, as opposed to the biological (biotic) parts.
Summarise Chapter 1 - What is an Ecosystem?
- 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.
Define Biotic Environment
The biological part of the environment as opposed to the abiotic (physical) parts.
Define Cladode
A flattened stem that takes on the function of leaves.
Define Community
All the living organisms in a habitat; the living part of an ecosystem.
Define Decomposition
The breakdown of complex organic compounds into simpler inorganic substances.
Define Ecosystem
A system formed by organisms interacting with one another and their physical environment.
Define Ephemeral
Plant with rapid lifecycle that can be completed in brief periods when water is available.
Define Epiphyte
A plant that grows on another plant for supports–it is not a parasite.
Define Geographic Distribution (range)
All the places where a species is found.
Define Habitat
The place where an organism lives.
Define Halophyte
A plant that is adapted to salty conditions and which has specialised mechanism for handling excess salt.
Define Humus
Organic matter formed from the breakdown of dead plants and animals; makes a dark layer in topsoil.
Define Intertidal Zone
Region (habitat) of rocky sea shore between the high and low tide marks.
Define Keystone Species
A species on which an ecosystem depends for its survival.
Define Lenticel
A group of loosely pack cells that allow gas exchange across the otherwise airtight waterproof cork layer covering the stems of plants.
Define Liane
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.
Define Limiting Factor
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.
Define Microhabitat
Small, particular part of a habitat in which particular organisms live, for example beneath the bark of a tree within a forest habitat.
Define Niche
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).
Define pH
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.
Define Photosynthesis
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.
Define Phyllode
A flattened leaf stem that takes on the function of leaf and carries out photosynthesis,
Define Population
A group of organisms of the same species living in a defined area.
Define Ratite
Any of the large flightless birds (the emu, kiwi, cassowary, ostrich and rhea) which lack barbules on the feathers and keel on the sternum.
Define Salinity
The concentration of salt found in water or soil
Define Sclerophyll
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.
Define Succulent
A plant that stores water in fleshy stems or leaves.
Define Viviparity
Giving birth to live young.
Define Xerophyte
A plant adapted to dry conditions.
Define Zonation
An arrangement of organisms along a environmental gradient.