Ecosystem Dynamics Overview

Ecosystem Dynamics

Definition: Ecosystem dynamics refers to the interactions and changes in ecosystems due to biotic (living) and abiotic (non-living) factors over time.
Components of Ecosystems:
- Biotic Factors:
  - Producers (e.g., plants)
  - Consumers (e.g., herbivores, carnivores, omnivores)
  - Decomposers (e.g., fungi, bacteria)
- Abiotic Factors:
  - Climate (temperature, precipitation)
  - Soil composition
  - Water availability
  - Light availability
Energy Flow:
- Energy enters ecosystems primarily through sunlight, captured by producers via photosynthesis.
- Energy is transferred through food chains and food webs from producers to various levels of consumers.
- Only about 10% of energy is transferred to the next trophic level (trophic efficiency).
Nutrient Cycling:
- Essential nutrients (e.g., carbon, nitrogen, phosphorus) are recycled through biogeochemical cycles.
  - Carbon Cycle: Involves photosynthesis, respiration, decomposition, and combustion.
  - Nitrogen Cycle: Includes nitrogen fixation, nitrification, assimilation, and denitrification.
  - Phosphorus Cycle: Involves weathering of rocks, uptake by organisms, and sedimentation.
Succession:
- Primary Succession: Occurs on previously uncolonized land (e.g., after a volcanic eruption).
  - Begins with pioneer species (e.g., lichens, mosses) that modify the environment.
- Secondary Succession: Follows disturbances that leave soil intact (e.g., forest fire, flooding).
  - Faster process due to existing soil and seed banks.
Stability and Resilience:
- Ecosystems exhibit stability through biodiversity, complexity, and interdependence.
- Resilience refers to an ecosystem's ability to recover from disturbances (e.g., natural disasters, human impacts).
Human Impact:
- Habitat destruction, pollution, climate change, and invasive species disrupt ecosystem dynamics.
- Conservation efforts aim to protect biodiversity and restore ecosystem functions.
Ecosystem Services:
- Ecosystems provide essential services:
  - Provisioning (food, water, raw materials)
  - Regulating (climate, floods, disease)
  - Supporting (nutrient cycling, pollination)
  - Cultural (recreation, spiritual benefits)

Ecosystem Dynamics Overview

Ecosystem dynamics encompasses interactions and changes within ecosystems influenced by both living (biotic) and non-living (abiotic) factors over time.

Components of Ecosystems

Biotic Factors:
- Producers: Organisms that create energy through photosynthesis, primarily plants.
- Consumers: Organisms that rely on other living beings for energy, divided into herbivores (plant eaters), carnivores (meat eaters), and omnivores (both).
- Decomposers: Break down dead organic material, including fungi and bacteria, facilitating nutrient recycling.
Abiotic Factors:
- Include environmental elements like climate (temperature and precipitation), soil composition, water availability, and light exposure.

Energy Flow

Sunlight is the primary energy source for ecosystems, harnessed by producers through photosynthesis.
Energy transfer occurs along food chains and webs, with only about 10% of energy passed to the next trophic level, highlighting the concept of trophic efficiency.

Nutrient Cycling

Essential nutrients such as carbon, nitrogen, and phosphorus are cycled through various biogeochemical processes.
Carbon Cycle: Involves steps including photosynthesis, respiration, decomposition, and combustion, maintaining carbon levels in the ecosystem.
Nitrogen Cycle: Comprises nitrogen fixation, nitrification, assimilation, and denitrification, crucial for plant growth.
Phosphorus Cycle: Includes weathering of rocks, nutrient uptake by organisms, and sedimentation in aquatic environments.

Succession

Primary Succession: Initiates on barren land (e.g., post-volcanic eruption) and starts with pioneer species like lichens and mosses that alter the environment.
Secondary Succession: Occurs after disturbances that leave soil intact (e.g., forest fires, floods); typically progresses faster due to pre-existing soil and seed banks.

Stability and Resilience

Ecosystem stability is supported by biodiversity, structural complexity, and species interdependence.
Resilience indicates an ecosystem's capacity to recover from disturbances, such as natural disasters or anthropogenic impacts.

Human Impact on Ecosystems

Activities such as habitat destruction, pollution, climate change, and introduction of invasive species severely disrupt ecosystem interactions.
Conservation efforts focus on protecting biodiversity and restoring ecosystems to maintain their functions.

Ecosystem Services

Ecosystems provide vital services:
- Provisioning Services: Supply food, water, and raw materials.
- Regulating Services: Modulate climate, control floods, and manage disease.
- Supporting Services: Essential for nutrient cycling and pollination processes.
- Cultural Services: Foster recreational opportunities and spiritual enrichment.