Ecology Essentials: Abiotic and Biotic Environmental Factors
Ecology Definition by Ernst Haeckel
Ernst Haeckel first used the term ecology. Ecology is the branch of natural science focused on the study of living organisms and their relationships with the abiotic and biotic environment.
Abiotic Factors
1. Water and Sanitation
Water is the universal solvent and a primordial factor in ecosystem formation. Alongside wind, it can change the geography of an area. It is a renewable natural resource, intervening through the hydrologic cycle, giving character to an ecosystem.
2. Sunlight
Sunlight is the main energy source for ecosystems, provoking significant effects. Due to the planet’s position, its incidence is not uniform, causing variations and decreases in temperature. In the aquatic environment, light penetration is affected by factors like cloudiness, latitude, moisture, dust, or smog concentration. For this reason, water receives partially filtered light and also experiences reflection. The maximum penetration appropriate for marine photosynthetic producers is about 250m.
Effects of Sunlight
The most important effect is chlorophyll production. Sunlight can directly influence the skin color of some animals. Temperature is one of its effects (related to ecological rules). Another phenomenon is taxis, which involves responses in plants and animals conditioned by sunlight susceptibility.
3. Temperature
Temperature is the thermal energy provided by sunlight, expressed in two ways: degrees (°C, °F, °K) and heat quantity (measured in calories contained in a body). The caloric content of material indicates the quantity of stored chemical energy it possesses.
4. Altitude, Latitude, and Temperature Relationship
Altitude and latitude have a relationship with temperature. In general, increases in latitude and altitude cause similar thermal effects. The average atmospheric temperature decreases by approximately 0.5°C for each degree of latitude increase or for every 100m increase in elevation. That is, a 100m increase in altitude is equivalent to a 1-degree increase in latitude in terms of temperature effect.
5. Atmosphere and Atmospheric Pressure
The atmosphere is a blend of gases containing approximately 20% Oxygen (O2), 79% Nitrogen (N2), and a combination of other gases. The atmosphere is divided into three main strata:
- Troposphere: The lower part, up to about 10,000m altitude.
- Stratosphere: The middle layer, between 10,000m and 40,000m.
- Ionosphere: The upper part, extending up to 100,000m.
Atmospheric pressure results from the force exerted by the air on a given point on the Earth’s surface. It varies with altitude and temperature, influencing weather events. At high altitudes, oxygen becomes scarce, making life virtually impossible, particularly for homeothermic vertebrates. The maximum altitude inhabited by humans is around 5,000m above sea level (e.g., Tibet). In the sea, pressure increases by approximately one atmosphere (atm) for every 10m of depth. Therefore, at 10,500m depth, the pressure is about 1050 atm, equivalent to a ton per square centimeter.
6. Mineral Salts
The elements required to form organic matter are primarily Oxygen (O), Nitrogen (N), Carbon (C), and Hydrogen (H), often utilized in salt form. Additionally, organisms require elements like Phosphorus (P), Potassium (K), Sulfur (S), Sodium (Na), Calcium (Ca), and Magnesium (Mg). Trace elements needed in lesser proportions include Cobalt (Co), Copper (Cu), Zinc (Zn), Chlorine (Cl), Iodine (I), Selenium (Se), Silicon (Si), Boron (B), Aluminum (Al), and Nickel (Ni) for the proper performance of certain functions.
Nutrient Classification
Classification based on importance to living things:
- Macronutrients: The first group, required by organisms in large quantities (e.g., C, H, O, N, P, K, S, Ca, Mg). They are indispensable components of carbohydrates, lipids, and proteins.
- Micronutrients (Trace Elements): The second group, chemical substances required in minimal but essential quantities by organisms for development.
Biotic Factors
These encompass all components directly related to living organisms, whether multicellular (animals, plants) or microbes.
1. Autotrophs
Autotrophs are organisms capable of producing or synthesizing their own food from inorganic substances.
Photosynthetic Organisms
Produce food using light energy through photosynthesis.
Chemosynthetic Organisms
Produce food from inorganic substances, such as Carbon Dioxide (CO2), using chemical energy (chemosynthesis).