Ecosystem Services and Extinction Risk

Ecosystem Services

  • Variety of Benefits from Ecosystems: Ecosystems provide essential services that support human life and contribute to well-being.

Types of Ecosystem Services

  1. Provisioning Services: Products obtained from ecosystems that provide consumable goods to humanity.

    • Examples of Provisioning Services:

      • Food

      • Medicine

      • Non-consumable goods

  2. Regulating Services: Benefits obtained from the regulation of ecosystem processes.

    • Examples of Regulating Services:

      • Climate Regulation

      • Soil Fertility

      • Water Purification

      • Biological Control (e.g., pollination, pest control)

      • Erosion Control

  3. Supporting Services: Ecological processes and functions that sustain other ecosystem services.

    • Examples of Supporting Services:

      • Nutrient Recycling

      • Biodiversity (increases resilience and supports ecosystems)

      • Air and Water Purification

  4. Cultural Services: Non-material benefits obtained from ecosystems, contributing to the cultural dimension of human well-being.

    • Examples of Cultural Services:

      • Recreation

      • Health and Well-being

      • Cultural Heritage

      • Spiritual and Religious values

Niche Partitioning

  • Definition: A process where species utilize limited resources in a way that reduces competition, leading to greater efficiencies in resource use.

    • Example of Niche Partitioning: Algae Species: Different species may thrive in unique niches, thus preventing resource overlap.

Dilution Effect

  • Definition: A biological mechanism that reduces the risk of infection by zoonotic pathogens by diminishing the prevalence of the pathogen among competent hosts.

    • Mechanism: Competent hosts are replaced by non-competent hosts, leading to lower disease transmission rates.

Extinction

  • Definition: The loss of a species that occurs with the death of the last individual of that species.

    • IUCN: The International Union for Conservation of Nature manages a Red List that characterizes the extinction risk of thousands of species and subspecies worldwide.

    • Key features of the IUCN Red List:

      • A comprehensive inventory of global conservation of biological diversity.

      • Uses well-defined biological criteria which are evaluated by expert teams of biologists and reviewers.

Levels of Extinction

  • Local Extinction: A species no longer exists in an area it once inhabited but can be found elsewhere.

  • Global Extinction: A species is no longer found anywhere on Earth.

    • Amphibians: Currently facing the highest risk of extinction due to habitat loss and climate change.

Characteristics Leading to Extinction

  • Factors Contributing to Increased Extinction Risk:

    • Isolation

    • Small population sizes

    • Low reproductive rates

    • Population density

    • Migration patterns

    • Stochastic events that randomly affect populations

Habitat Loss

  • Definition: The complete elimination of habitats, along with their biological communities and ecological functions.

    • Habitat Fragmentation: The process by which larger continuous habitats are subdivided into smaller patches.

    • Habitat Degradation: A range of human activities that disrupt habitat quality and make it less conducive to life, risking biodiversity.

Major Causes of Habitat Loss

  • Urbanization: Expansion of cities leading to habitat destruction.

  • Agriculture: Land conversion for agricultural purposes resulting in loss of natural habitats.

  • Extractive Industries: Industries such as mining and logging contributing to habitat destruction.

  • Pollution: Introduction of wastes that degrade the quality of natural habitats.

Overexploitation

  • Definition: The unsustainable harvest of renewable resources, leading to their depletion.

    • Types of Overexploitation:

      1. Commercial Overexploitation: Legal and illegal trafficking of wildlife driven by monetary gains.

      2. Subsistence Overexploitation: Unsustainable hunting and harvesting of wildlife for food.

      3. Recreational Overexploitation: Hunting and fishing for pleasure that may lead to the decline of species populations.

CITES

  • Convention on International Trade in Endangered Species of Wild Fauna and Flora: A treaty aimed at protecting endangered plants and animals by regulating unsustainable wildlife trade.

Invasive and Alien Species

  • Definition: Species that are introduced into a new habitat, where they can cause harm to the ecosystem and threaten biodiversity.

    • Examples of Invasive Species: Asian hornet.

Hypotheses of Bio Interactors influencing Invasive Species

  1. Empty Niche Hypothesis: Invaders exploit vacant niches in new environments.

  2. Novel Weapons Hypothesis: Invaders gain competitive advantages through unique chemicals that harm native species.

  3. Enemy Release Hypothesis: Invaders lack natural predators and therefore can thrive in new environments.

  4. Navel Environment Hypothesis: Invasive species adapt well to modified environments.

Phases of Invasive Species Population Dynamics

  1. Lag Phase: Initial slow growth and low spread rate.

  2. Expansion Phase: Exponential growth and rapid spread.

  3. Saturation Phase: Growth rates plateau and the population stabilizes.

Invasive Species Management Plan

  • Developing a Risk Assessment: To prioritize management strategies effectively.

  • Management Options: Strategies to control and mitigate the spread of invasive species while minimizing ecological impact.