Global Ecology

Global Ecology Overview

  • Global Ecology: Study of interactions among organisms and abiotic components within the entire biosphere.

    • Biosphere: The zone on, above (atmosphere), and below (subsurface) the earth’s surface where life exists.

    • Research Example: How will changes in the carbon cycle affect sockeye salmon geographic distribution and abundance?

Water Cycle: Reservoirs and Transfer Processes

  1. Reservoirs of Water Cycle:

    • Atmosphere

    • Organisms (primarily plants)

    • Earth surface and subsurface

  2. Transfer Processes:

    • Precipitation

    • Evaporation

    • Uptake and release by organisms

    • Surface and subsurface flow

Human Impacts on the Water Cycle

  • Plant Biomass Reduction: Alters the water cycle leading to:

    • Increased surface runoff and evaporation.

    • Altered precipitation patterns (more extreme events and droughts).

  • Effects on Human Welfare: Changes in water availability, agricultural productivity, and increased flood risk.

Carbon Cycle: Reservoirs and Transfer Processes

  1. Reservoirs of Carbon Cycle:

    • Atmosphere

    • Organisms

    • Earth’s subsurface (soil, sediment, fossils)

  2. Carbon Transfer Processes:

    • Processes Reducing Atmospheric Carbon:

      • Uptake by primary producers

      • Storage in biomass and subsurface

    • Processes Increasing Atmospheric Carbon:

      • Cellular respiration

      • Burning of fossil fuels and wood (deforestation)

Human Impacts on the Carbon Cycle

  • Increase in Atmospheric Carbon: Resulting from human activities such as fossil fuel combustion and deforestation.

  • Climate Change: Environmental consequence has negative impacts on human welfare.

Climate Change and Its Causes

  1. Climate Change Defined: Alteration in long-term temperature and precipitation patterns due to global warming.

  2. Global Warming: Increase in Earth's average temperature.

  3. Causes:

    • Increased concentrations of greenhouse gases (e.g., CO2) trapping solar energy.

    • Results from fossil fuel combustion and declining plant biomass.

Impacts of Climate Change on Biological Production and Species Diversity

  1. Water Cycle Alteration:

    • Increased air temperature changes water availability with more extreme precipitation and droughts.

    • Melting polar ice results in rising sea levels, reducing land area.

  2. Decline in Net Production and Species Diversity:

    • Stressful abiotic conditions such as high temperatures and low water availability.

    • Loss of biotic resources leading to extinctions (prey, hosts, mutualistic partners).

  3. Dispersal Capacity:

    • Extinction avoidance depends on species' ability to adapt or shift geographic ranges requiring genetic diversity.

Impacts of Climate Change on Human Welfare

  • Challenges Faced by Humans:

    • Stress from abiotic conditions: higher temperatures, reduced water availability, increased storm intensity.

    • Habitat loss due to reduced land area.

    • Loss of biotic resources and ecosystem services resulting from reduced abundance and diversity of organisms.