Key Ecological Concepts: Cycles, Pollutants, and Factors
Wilson Cycle and Supercontinents
The Wilson Cycle proposes that every 400-500 million years, all land masses join together to form a supercontinent. Pangea was the last supercontinent, and it is currently disintegrating. Before Pangea, there was likely another supercontinent called Pannotia. This cycle is related to the Hercynian orogeny, which was important in forming the oldest reliefs in the Iberian Peninsula.
Water Pollutants
Water pollutants include any living organisms, chemicals, or forms of energy present at levels exceeding normal. These include:
- Pathogenic microorganisms
- Organic wastes
- Inorganic chemicals
- Inorganic nutrients
- Organic compounds
- Sediments and suspended materials
- Radioactive substances
- Thermal pollution
Biosphere, Ecosystem, and Biotic/Abiotic Factors
The biosphere is the layer of Earth where life exists. It encompasses and interacts with the hydrosphere, geosphere, and atmosphere.
An ecosystem is a zone within the biosphere consisting of living organisms and their physical environment, characterized by the exchange of matter and energy.
The biotic component of an ecosystem is formed by living organisms of different species that interact with one another.
The abiotic component of an ecosystem (the biotope) consists of the chemical and physical components of the environment.
Limiting Factors of Primary Production
The limiting factors of primary production include:
- Temperature: Higher temperatures generally lead to faster plant growth.
- Moisture: Lack of water inhibits photosynthesis in plants.
- Nutrients: Nutrients are necessary for creating organic matter along with CO2 and H2O.
- Light: Light is essential for plant growth. Primary production increases with light intensity up to a maximum rate, after which photosynthesis stabilizes.
Volcanoes in the Canary Islands
There are three main volcanic areas: Olot, Cabo de Gata, and the Canary Islands. In the Canary Islands, approximately 17 eruptions have occurred, with Timanfaya being the most significant. Volcanoes in the Canary Islands are still active, with the most recent eruption occurring in Fuencaliente, La Palma. Tenerife has experienced more eruptions than other islands. The risk from eruptions is low compared to emissions from explosive-type volcanoes.
Strategies of Reproduction: R and K
R-strategists are individuals with high biotic potential (high TN), meaning they have many offspring that do not receive care, and few survive (high TM). This maintains a steady population size (e.g., fish).
K-strategists have a smaller TN, meaning they have few offspring. However, the TM is lower since most offspring reach adulthood (e.g., mammals).
Competition and Niche
Competition is a relationship between individuals of one or more species that use the same resource and cannot coexist. This occurs both within the same species (intraspecific competition) and between different species (interspecific competition).
A niche is the set of circumstances, relations with the environment, and ecological functions that define the role of a species in an ecosystem. Types of niches include:
- Potential niche: Satisfies all the needs of a particular species.
- Ecological niche: The niche occupied by a species under natural conditions.
Predator-Prey Model
The predator-prey model is stabilizing because it is based on a negative feedback loop (who eats whom).
Law of Minimum (Liebig’s Law)
According to Liebig’s Law of the Minimum, plant growth is limited by the single element that is found in the lowest quantity relative to its need, acting as a limiting factor.