Introduction
Relevance of the Theme
Ecology: Ecological Relationships, is a fundamental study of Biology that investigates the interactions between organisms and the environment in which they live. Understanding these ecological relationships is crucial, as they form the basis of all ecosystems, controlling their structure and functioning. These relationships constitute the invisible threads that interconnect living beings, forming a complex and interdependent web of life. Through these relationships, living beings obtain food, reproduce, protect themselves, and interact with each other and the environment. Exploring this theme provides a broader view of ecological processes and allows for a more coherent understanding of ecosystem dynamics.
Contextualization
The study of Ecological Relationships is situated in the broader context of Ecology, one of the main subdivisions of Biology. In the Biology curriculum, the theme of Ecological Relationships is generally introduced after the study of basic Biology concepts, such as the cell and the chemical composition of life. This is because understanding ecological processes requires a prior appreciation of the structure and function of the organisms that perform them. Furthermore, the theme is directly connected to other topics in the discipline, such as Biodiversity, Environmental Conservation, and Evolution, allowing students to develop a holistic view of Biology. Therefore, understanding Ecological Relationships is essential for the comprehensive education of the student, enabling them to understand and interpret natural phenomena, and contribute to the responsible and sustainable development of society.
Theoretical Development
Components
- Ecological Interactions: Comprehends the interactions between organisms of the same species (intra-specific) and between organisms of different species (inter-specific), which can be harmonious (mutualism, commensalism) or disharmonious (predation, competition, parasitism). These relationships shape important characteristics of ecosystems, such as population dynamics and community structure.
- Food Chains and Webs: Represent the passage of energy and matter between the different trophic levels of an ecosystem. Each trophic level is occupied by a group of organisms that share a position in the food web, with producers at the base and decomposers at the top. Studying these relationships allows us to understand the complex interdependence of species in an ecosystem.
- Energy Flow and Nutrient Cycling: Energy flows through an ecosystem, passing from one organism to another in a sequence called a food chain. The energy captured by producers is transferred to primary consumers, secondary consumers, and so on. Meanwhile, nutrients such as carbon, nitrogen, and phosphorus replenish the environment through biogeochemical recycling.
Key Terms
- Interaction: Reciprocal action between organisms or between them and the environment in which they live, which can be beneficial, harmful, or neutral.
- Symbiosis: Close and lasting relationship between individuals of different species, which can be beneficial (mutualism), neutral (commensalism), or harmful (parasitism).
- Predation: Interrelationship where one organism kills and feeds on another organism, commonly called prey.
- Competition: Interrelationship in which two or more organisms compete for the same resources, such as food, water, territory, or light.
- Biogeochemical Cycle: Process of transport and transformation of chemical elements in the biosphere through interactions between the living part (bio), the atmosphere (geo), and the lithosphere (chemicals).
Examples and Cases
- Mutualism between insects and flowers: Plants offer nectar, a food source, to insects that, in return, help in pollination.
- Predation in the Ocean: Larger fish feed on smaller fish, which in turn feed on planktonic organisms, demonstrating a trophic chain.
- Competition between lions and hyenas: Both species compete for hunting, sometimes stealing prey from each other.
- Nitrogen Cycle: Nitrogen from the air is fixed by bacteria in the soil, absorbed by plants, consumed by herbivores, and eventually released in the decomposition of organic material.
Detailed Summary
Key Points
- The importance of ecological relationships: Ecological relationships are the links that connect living beings and regulate ecosystem functioning. They allow for the transfer of energy and nutrient cycling, enabling the survival of organisms in their habitat.
- Types of ecological relationships: Ecological relationships can be harmonious (mutualism, commensalism) or disharmonious (predation, competition, and parasitism), depending on the effect they have on the species involved.
- Food Chains and Webs: Food chains and webs represent the sequence of energy transfer between organisms in an ecosystem. They demonstrate the interconnection and dependence of species on each other.
- Energy Flow and Nutrient Cycling: Energy flow and nutrient cycling are the processes that sustain life in an ecosystem. Energy flows in one direction while nutrients are recycled, passing repeatedly through living beings and the environment.
Conclusions
- Need for biodiversity: Biodiversity is essential for ecosystem stability, as the more varied the species in an ecosystem, the more varied the ecological relationships that can be established.
- Impact of disturbances: Disturbances, such as the introduction of exotic species or habitat destruction, can interfere with ecological relationships and cause significant changes in ecosystems.
- Interdependence of living beings and the environment: Ecological relationships demonstrate that life on Earth is deeply interconnected and depends on the integrity of the environment in which it develops.
Exercises
- Describe the process of predation and provide an example illustrating this relationship in an ecosystem.
- Construct a food chain for a marine ecosystem and identify the different trophic levels.
- Explain what biogeochemical cycles are and give an example of a cycle involving a nutrient essential for life.
