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.