Cycles of Matter

Cycles of Matter Overview

  • Water's Role in Biogeochemical Cycles

    • Water is a universal solvent due to its chemical and physical properties including hydrogen bonding.

    • Essential for transporting nutrients and participating in the cycling of matter in ecosystems.

Importance of Nutrients in Plants

  • All living organisms, including plants, require matter to build cellular structures and generate energy.

  • Key nutrients for plants include sulfur, nitrogen, and phosphorus, which are essential for growth and energy metabolism.

Elements Transfer in the Environment

  • Elements like Oxygen (O), Carbon (C), Nitrogen (N), and Sulfur (S) can be easily transferred globally.

  • Elements such as Iron or Phosphorus are found in soil but not typically in the atmosphere, affecting their availability.

Hydrologic Cycle

  • Water in Different States:

    • About 97% of Earth's water is liquid; 2.1% is frozen as ice; and significant amounts vaporize from oceans (86%).

    • Water’s ability to exist in different states plays a crucial role in climate and weather patterns.

Properties of Water

  • Bonds in Water:

    • Water consists of a polar molecule formed by covalent bonds between hydrogen and oxygen, resulting in hydrogen bonding between water molecules.

  • Specific Heat Capacity:

    • Water requires a high amount of energy to change states (high specific heat), stabilizing temperatures in environments.

Density, Cohesion, and Adhesion

  • Density: Cold water is less dense due to loosened hydrogen bonds, allowing ice to float.

  • Cohesion and Adhesion: Water molecules attract each other (cohesion) and to other substances (adhesion), facilitating processes like transpiration in plants.

Water’s Function in Life

  • Clean freshwater is essential for all life, making up ~70% of the adult human body and ~95% of plant tissues.

  • Metabolism relies on water balance, including consumption, retention, and loss.

Human Impact on Cycles

  • Increased CO2 emissions from human activities lead to a buildup of greenhouse gases, impacting ecosystems.

  • This vicious cycle results in reduced transpiration by plants, consequently affecting water availability.

Carbon and Oxygen Cycles

  • Nutrients cycle through reservoirs (soil, air, water, organisms) and can be categorized into rapid (biological processes) and slow cycling (long-term storage like fossil fuels).

  • Rapid cycling involves processes like photosynthesis, respiration, and decomposition, while the slow carbon cycle incorporates long-term sequestration in geological formations.

Carbon Sinks vs. Sources

  • Carbon Sinks: Absorb more carbon than they emit (e.g., forests).

  • Carbon Sources: Emit more carbon than absorbed (e.g., fossil fuel combustion).

Sulfur Cycle

  • Sulfur from rocks and fossil fuels is released into the atmosphere through volcanic activity and human actions (e.g., burning fossil fuels).

  • Acid precipitation can harm ecosystems, demonstrating the impact of elevated sulfur levels from anthropogenic sources.

  • Acid precipitation (harms ecosystems)

Phosphorus Cycle

  • Phosphorus, crucial for living organisms, mainly cycles through soil and water and is not found in the atmosphere.

  • Limited in supply, phosphorus must be transferred from rocks through weathering and often is applied as fertilizer in agriculture.

  • Not in the atmosphere (found in rocks in bodies of water)

  • Found in DNA and ATP (energy)

Algal Blooms

  • Excessive phosphorus can lead to algal blooms, which disrupt aquatic ecosystems by depleting oxygen and harming aquatic life. (Promote algae growth taking up oxygen)

Nitrogen Cycle

  • Nitrogen fixation by bacteria converts atmospheric nitrogen into forms usable by plants (e.g., ammonium, nitrates), essential for proteins and nucleic acids.

  • Decomposition and human activities can affect nitrogen levels in soil, impacting plant growth significantly.

Interrelationship of Energy and Matter

  • Ecosystem productivity reflects the rate at which producers convert solar energy into organic compounds and can be influenced by factors like light availability and nutrient levels.

  • Sustainability of ecosystems depends on balanced energy and matter exchanges, which can be affected by human activities like pollution and land use changes.

Productivity

  • Productivity is amount of energy made by photosynthesis (changes between

  • Factors

-number of producers

-amount of light and heat

-amount of rain

-nutrients

Eutrophication

Dead zones: regions of lakes or oceans in which aquatic life has suffocated due to algal blooms

  • Nutrients washed into rivers by rain

  • Sewage washed into the body of water that has a lot of phosphate & nitrate

  • Surface runoff that bring manure from livestock

  • Runoff from fertilizer

Wetlands (bogs, marshes, swamps) act as a giant filters as they are saturated with water.

Conclusion

  • Understanding the interconnected cycles of matter and energy is critical for maintaining ecosystem health and supporting sustainability initiatives in response to environmental changes and human impacts.