Lecture 7 Flashcards
What is the primary cause of pollinator decline globally?
A. Climate change
B. Habitat loss and fragmentation
C. Pesticide use
D. Introduction of alien species
B. Habitat loss and fragmentation
Explanation: Habitat loss has been identified as the most significant driver of pollinator population declines worldwide.
Which of the following is a key feature of integrated pest management (IPM)?
A. Increased pesticide application
B. Use of genetically modified crops
C. Preventive measures like crop rotation
D. Heavy reliance on chemical pest control
C. Preventive measures like crop rotation
Explanation: IPM emphasizes non-chemical preventive measures and uses pesticides only as a last resort to minimize environmental impact.
How does climate change exacerbate pollinator declines?
A. By increasing the number of alien species introduced to ecosystems
B. By causing temporal and spatial mismatches between plants and pollinators
C. By increasing genetic dilution in native pollinators
D. By reducing the use of neonicotinoid pesticides
B. By causing temporal and spatial mismatches between plants and pollinators
Explanation: Climate change alters flowering times and pollinator activity, disrupting their mutualistic relationships.
What is the economic significance of pollinators for global agriculture?
A. They contribute to 5% of agricultural production
B. They add over €150 billion in economic value annually
C. They are only relevant for fruit crop production
D. Their role is largely ornamental rather than economic
B. They add over €150 billion in economic value annually
Explanation: Pollinators significantly enhance crop yields and food security globally.
Explain the primary drivers of pollinator decline.
Key drivers include habitat loss and fragmentation, pesticide use, decreased resource diversity, introduction of alien species, climate change, and the spread of pathogens. These factors often interact, compounding their negative effects on pollinator populations.
How do changes in land use impact pollinator diversity and abundance?
Land use changes, such as urbanization and intensive farming, reduce natural habitats and floral diversity. This limits nesting sites and food resources, leading to declines in pollinator populations.
What role do pesticides play in pollinator health?
Pesticides, particularly neonicotinoids, directly harm pollinators through toxicity and indirectly reduce floral resources. They can impair foraging behavior, colony growth, and reproduction.
Describe the ecological consequences of pollinator decline for ecosystems.
Pollinator declines disrupt plant reproduction, leading to reduced genetic diversity and population sizes in plants. This affects entire ecosystems, as plants provide resources and habitat for other species.
Why is genetic dilution a concern with the introduction of alien pollinators?
Alien pollinators can interbreed with native populations, reducing genetic diversity and potentially leading to the extinction of local subspecies.
What is temporal mismatch, and how does it relate to pollination?
Temporal mismatch occurs when the timing of plant flowering does not align with pollinator activity due to climate change. This reduces pollination success and crop yields.
Explain the concept of economic vulnerability in crops dependent on insect pollination.
Economic vulnerability measures the potential production loss due to pollinator decline. Crops like fruits and vegetables are highly vulnerable, while staples like cereals are less dependent.
How does the loss of wild pollinators differ from declines in managed honeybee populations?
Wild pollinator losses have broader ecological impacts, affecting biodiversity and ecosystem stability, whereas managed honeybee declines primarily impact agricultural productivity.
What strategies can mitigate the impact of pathogens on pollinator populations?
Strategies include strict quarantine controls, breeding disease-free managed pollinators, and monitoring programs to detect and manage outbreaks early.
Why is habitat restoration critical for pollinator conservation?
Restored habitats provide essential nesting sites and diverse floral resources, improving pollinator health and resilience against other stressors.
Evaluate the interplay between climate change and agricultural intensification in pollinator decline.
Climate change exacerbates the effects of agricultural intensification by altering pollinator behaviors and reducing habitat suitability. Combined, these stressors decrease pollinator diversity and ecosystem resilience.
Analyze how the introduction of alien plants impacts native plant-pollinator interactions.
Alien plants can provide additional nectar resources for generalist pollinators but often outcompete native plants for pollinators. This disrupts native plant reproduction and ecosystem dynamics.
How do multiple stressors, such as pesticides and habitat loss, interact to amplify pollinator declines?
These stressors act synergistically, with habitat loss reducing available resources and pesticides further impairing pollinator health. Together, they limit pollinator survival and reproductive success.
Assess the potential risks of over-reliance on managed pollinators for global agriculture.
Over-reliance increases vulnerability to disease outbreaks and supply failures. It also reduces the ecological benefits provided by diverse wild pollinators, which are essential for resilient ecosystems.
Case Study: Analyze the relationship between habitat size and pollinator diversity using data from limestone quarries in Germany.
Research in German limestone quarries found that larger habitats support greater pollinator diversity and density. This underscores the importance of habitat size for maintaining pollinator populations.
Case Study: Discuss the effects of Bombus terrestris introduction in Chile on native bumblebee populations.
The introduction of Bombus terrestris led to competition for resources and pathogen spillover, causing declines and local extinction of native Bombus dahlbomii populations. This highlights the risks of introducing non-native pollinators.
