Global Species Diversity: Published records exist for all species discovered and named, but estimating the total number of species on Earth remains challenging. IUCN (2004): Over 1.5 million species of plants and animals have been described. Unknown Species: Estimates vary widely; many are educated guesses, with tropical regions having...
Introduction: If an alien were to visit Earth, the first thing that would amaze him is the enormous diversity of life on the planet. Even humans find it astonishing and fascinating that there are so many living organisms. Examples of the staggering variety: More than 20,000 species of ants...
Definition Ecological pyramids are graphical representations of the relationship between organisms at different trophic levels in terms of number, biomass, or energy. The pyramid’s base represents producers (first trophic level), while the apex represents tertiary or top-level consumers. Types of Ecological Pyramids Pyramid of Numbers Represents the number of...
Energy Source and Photosynthetically Active Radiation (PAR) The Sun is the primary energy source for all ecosystems (except deep-sea hydrothermal ecosystems). Of the total incident solar radiation, less than 50% is PAR. Plants capture only 2-10% of PAR through photosynthesis, which sustains the entire living world. Energy Flow Characteristics Energy flows in a unidirectional manner:...
Definition of Decomposition Decomposition: The process of breaking down complex organic matter into simpler inorganic substances like carbon dioxide, water, and nutrients. Role of Detritus Detritus: Dead plant remains (e.g., leaves, bark, flowers) and animal remains, including fecal matter, serve as the raw material for decomposition. Steps in the...
Productivity in Ecosystems Definition of Productivity Productivity: Rate of biomass production in an ecosystem, expressed in: Weight: gm⁻² yr⁻¹ Energy: kcal m⁻² yr⁻¹ Productivity helps compare different ecosystems. Types of Productivity Primary Productivity: Biomass or organic matter produced by plants through photosynthesis. Gross Primary Productivity (GPP): Total rate of...
Ecosystem – Structure and Function Introduction An ecosystem consists of biotic (living) and abiotic (non-living) components. These components interact, influencing each other and their environment. The flow of energy within an ecosystem integrates these components into a functional unit. Physical Structure of Ecosystems Physical Structure: Formed by interactions between...
Definition of Ecosystem An ecosystem is a functional unit of nature where living organisms (biotic components) interact among themselves and with their surrounding physical environment (abiotic components). Key Features of Ecosystems Interactions: Organisms interact with each other and with the physical environment. These interactions form cycles, chains, and webs...
Definition & Importance of Predation: Predation is a natural process where one organism (predator) hunts and consumes another (prey). It serves as a means of transferring energy fixed by autotrophic organisms (plants) to higher trophic levels in the food chain. Predation helps regulate the population of prey species, ensuring...
Interspecific Interactions: These interactions arise from the interaction of populations of two different species. They can be: Beneficial: One or both species benefit. Detrimental: One or both species are harmed. Neutral: Neither species benefits nor is harmed. Key Types of Interactions (with symbols): Mutualism (+ +): Both species benefit...