IGCSE Biology 11 Views 1 Answers
State that through altering food webs and food chains, humans can have a negative impact on habitats
State that through altering food webs and food chains, humans can have a negative impact on habitats
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Humans significantly influence ecosystems by altering food webs and food chains, which can lead to negative impacts on habitats. Here’s how these alterations occur and their consequences:
Alteration of Food Webs and Food Chains
- Overfishing: The removal of key species from marine ecosystems disrupts food chains. For instance, overfishing of predator species can lead to an overabundance of prey species, which may then overgraze or deplete their own resources. This imbalance can cause cascading effects throughout the ecosystem, ultimately harming habitat integrity.
- Introduction of Invasive Species: When humans introduce non-native species—intentionally or accidentally—these organisms can outcompete, prey upon, or otherwise negatively affect native species. This alteration can disrupt existing food webs, leading to declines in native populations and changes in habitat structure.
- Agricultural Practices: Intensive farming often focuses on monocultures (growing a single crop) that can simplify food webs. The use of pesticides and herbicides not only targets pests but can also harm beneficial organisms, including pollinators and natural predators, further destabilizing local ecosystems.
- Habitat Fragmentation: Urban development and infrastructure projects can fragment habitats, isolating populations and disrupting their interactions within food webs. Species that rely on specific habitats for feeding or breeding may decline in numbers, leading to reduced biodiversity.
Consequences of Altered Food Webs
- Biodiversity Loss: Disruptions in food webs can lead to the decline or extinction of certain species, reducing overall biodiversity. This loss diminishes the resilience of ecosystems, making them more vulnerable to environmental changes.
- Ecosystem Imbalance: Changes in predator-prey relationships can result in overpopulation or extinction of certain species, leading to imbalances that affect nutrient cycling, plant growth, and overall ecosystem health.
- Habitat Degradation: As certain species decline or disappear, the habitats they helped maintain may degrade. For example, the loss of herbivores can lead to unchecked plant growth, while the loss of predators can result in overpopulation of smaller herbivores, both of which can alter habitat structure and function.
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