Biodiversity

Biodiversity Overview

  • Definition: Biodiversity, or biological diversity, is the variety of life found on Earth, encompassing all living species including plants, animals, bacteria, and fungi.

  • Global Context:

    • The Philippines is one of the 17 megadiverse countries, hosting over 70% of the world’s known species.

    • It exhibits high biodiversity and endemism but faces severe environmental degradation and species loss.

Types of Biodiversity

1. Genetic Diversity

  • Refers to the variety of different versions of genes within individual species.

2. Species Diversity

  • Describes the number of different kinds of organisms within communities or ecosystems.

3. Ecological Diversity

  • Assesses the richness and complexity of biological communities.

Species Definition

  • Various concepts define species:

    • Biological Species Concept: Groups of organisms that can breed and produce fertile offspring.

    • Phylogenetic Species Concept: Emphasizes the branching relationships among species.

    • Evolutionary Species Concept: Defines species in the context of evolutionary history.

Biodiversity Hotspots

  • Identification:

    • Defined by Norman Myers and Russell Mittermeier as areas with at least 1,500 endemic species that have lost at least 70% of their habitat.

    • 34 hotspots proposed due to high biodiversity and significant human threats.

  • Geographical Trends:

    • Typically found in tropical or Mediterranean climates, on islands, coastlines, or mountains.

Importance of Biodiversity

  • Contributes to ecosystems' health, stability, and resilience.

  • Provides food resources, medicines, and ecosystem services such as pollination and carbon storage.

Threats to Biodiversity

1. Habitat Destruction

  • Major causes include clear-cutting forests, converting grasslands to croplands, and resource extraction (e.g., mining, dam building).

  • Techniques such as bottom trawling in fishing are disastrous, destroying marine habitats.

2. Invasive Species

  • Non-native species introduced accidentally or deliberately can disrupt local ecosystems.

  • Often labeled alien, exotic, or disruptive.

3. Pollution

  • Toxic pollutants adversely affect wildlife populations, with pesticides and lead poisoning causing significant mortality in species.

4. Human Overpopulation

  • Growing populations lead to increased demands for resources, resulting in habitat degradation and over-exploitation of species.

5. Overharvesting

  • Unsustainable practices have led to the decline or extinction of numerous species, such as the American passenger pigeon.

  • Overfishing impacts ecosystems dramatically, leading to ecological imbalances.

Endangered Species Management

Wildlife Protection Legislation

  • R.A. 9147 Wildlife Act of 2001: Aims to conserve wildlife resources and their habitats.

    • Objectives include regulating wildlife collection and trade and supporting biodiversity research.

Species Categories

  • Critically Endangered: Extremely high risk of extinction.

  • Threatened: Likely to become endangered in the foreseeable future.

  • Endangered: Unlikely to survive if threats persist.

  • Vulnerable: At risk due to adverse factors but not critically endangered.

  • Endemic Species: Naturally occurring only in specific areas.

  • Exotic Species: Introduced non-native species.

  • Economically Important Species: Have potential commercial value.

Conservation Strategies

  • Breeding Programs: Zoos and botanical gardens work on species survival through captive breeding.

  • Community Involvement: Public actions to help preserve biodiversity include restoring native biomes, planting native species, and following conservation legislation.