Interactions Between Natural Ecosystems

Natural ecosystems are characterized by dynamic change rather than remaining in a static state.
Ecosystems do not exist in isolation; they continuously interact with each other in multifaceted ways.

Variations in ecosystems can occur across two primary dimensions: temporal and spatial.
Temporal changes involve the variation of a specific variable over a period of time.
- Example: Temperature on land typically undergoes significant fluctuations between the hours of night and day.
Spatial changes involve the variation of a specific variable across a physical distance.
- Example: In Queensland (QLD), the density and amount of vegetation decreases progressively as one travels further West.
Changes in populations of organisms can manifest over both short-term and long-term intervals.
Key factors influencing these changes include different times of the year, as well as specific latitudinal and altitudinal zones.

Environmental exposure varies significantly based on the medium in which an organism lives:
- Land animals and plants: These organisms are subjected to substantial changes in both temperature and moisture levels.
- Water organisms: These organisms typically experience only minor fluctuations in temperature.
To survive environmental extremes, some organisms utilize specialized physiological states to manage heat and hydration:
- Torpor: A state where the metabolism slows down significantly.
- Aestivation: A specific form of dormancy that allows animals to stay cool and prevent critical water loss.
Biological examples include cases such as underground frogs, which enter mainstream ecological focus due to these survival mechanisms.

Boundaries between ecosystems are rarely precise or sharply defined.
Interactions often occur in areas of species overlap.
Buffer zones: These are specific regions where species from two adjacent ecosystems interact with one another.
The distribution of organisms is heavily influenced by geography and climate:
- Altitude: This refers to the height of a location above sea level.
- Latitude: This refers to a location's position relative to the equator.
Variations in altitude and latitude directly affect temperature, which in turn influences wind patterns, rainfall, and humidity levels.

Organisms actively interact with their environment and possess the capacity to cause physical and chemical changes to their surroundings.
Organisms bring about these changes through the following mechanisms:
- Provision of food sources for other species.
- Provision of physical habitats.
- Extraction and removal of water from the environment.
- Extraction and removal of essential nutrients.
- Addition of organic matter to the ecosystem through the process of waste elimination.
- Absorption of light, which impacts energy availability.
- Provision of shade, which alters local microclimates.
- Alteration of atmospheric gas levels, specifically changing concentrations of Carbon Dioxide ( $CO_2$ ) and Oxygen ( $O_2$ ).