Biodiversity Flashcards
(196 cards)
What is biodiversity?
Biodiversity refers to the wide range of life forms present on Earth, encompassing the variety of species, genes, ecosystems, and ecological processes.
It includes the diversity within and between species, as well as the diversity of ecosystems and habitats.
List 2-3 reasons why biodiversity is important.
a. Ecosystem Services: Biodiverse ecosystems provide essential services such as pollination, water purification, nutrient cycling, and climate regulation.
b. Medicine and Agriculture: Many pharmaceuticals and agricultural products are derived from diverse species.
c. Genetic Diversity: Genetic diversity within species helps them adapt to changing environments and diseases.
d. Cultural and Aesthetic Value: Biodiversity has cultural significance and provides recreational and aesthetic enjoyment.
How does biodiversity contribute to ecosystem stability?
a. Redundancy: Multiple species can perform similar functions, ensuring that if one species is lost, another can take its place.
b. Resilience: Diverse ecosystems are more adaptable to environmental changes and disturbances.
c. Ecosystem Services: Biodiverse ecosystems offer a wider range of services, making them more resistant to disruptions.
d. Complexity: Interactions between different species create intricate ecological networks that stabilize ecosystem dynamics.
How is biodiversity measured or assessed?
a. Species Richness: Counting the number of different species in a given area.
b. Species Evenness: Measuring the relative abundance of each species within a community.
c. Simpson’s Diversity Index: Calculating the probability that two individuals randomly selected from a sample belong to different species.
d. Genetic Analysis: Studying DNA to understand genetic diversity within species.
e. Remote Sensing: Using satellite imagery to analyze ecosystem diversity.
How do scientists estimate the number of species currently existing on Earth?
a. Taxonomic Expertise: Taxonomists identify and classify species based on physical and genetic characteristics.
b. Species-Area Curves: Scientists study the relationship between area and species richness to estimate total species numbers in a given habitat.
c. DNA Barcoding: Analyzing specific DNA sequences helps identify species even when they appear similar.
How does the current number of species on Earth compare to past levels of biodiversity?
a. The current number of species on Earth is just a fraction of the total number of species that have existed throughout Earth’s history.
b. Estimates suggest that over 99% of all species that have ever lived are now extinct.
c. Biodiversity has undergone periods of expansion and contraction due to various factors, including mass extinctions and evolution.
What are some examples of species extinction?
North Island giant moas (Dinornis novaezealandiae) as an example of the loss of terrestrial megafauna, Caribbean monk seals (Neomonachus tropicalis) as an example of the loss of a marine species.
How does the concept of “background extinction” contrast with mass extinctions?
a. Background extinction refers to the normal, ongoing rate of species extinction that occurs throughout Earth’s history due to factors such as competition, predation, and environmental changes.
b. Mass extinctions, on the other hand, are sudden and catastrophic events that lead to a significant percentage of species going extinct over a short period, disrupting ecosystems on a global scale.
What is anthropogenic species extinction?
a. Anthropogenic species extinction refers to the extinction of species caused by human activities.
b. These activities directly or indirectly lead to changes in the environment that result in the decline and eventual disappearance of species from the Earth.
Provide a real-world example of how each of the following contributes to species extinction: Habitat Destruction, Pollution, Climate change, Overexploitation, invasive species, disease, global trade.
a. Habitat Destruction: The rapid deforestation of the Amazon rainforest for agricultural expansion, logging, and infrastructure development destroys the habitats of countless species, including plants, animals, and insects. This leads to displacement, reduced food availability, and increased vulnerability to predators.
b. Pollution: Plastic pollution in oceans poses a severe threat to marine species. Sea turtles, for instance, often mistake plastic bags for jellyfish, a common part of their diet. Ingesting plastic can lead to blockages, malnutrition, and death among sea turtles.
c. Climate Change: Rising sea temperatures due to climate change cause coral bleaching, where corals expel their symbiotic algae and turn white. This weakens the corals, making them more susceptible to diseases and reducing their ability to provide habitat and resources for various marine species.
d. Overexploitation: Overfishing of the Atlantic cod in the North Atlantic Ocean has led to a drastic decline in their populations. The demand for cod as a food source. This overexploitation not only led to the collapse of cod populations but also had cascading effects on the marine food web and the livelihoods of fishing communities.
e. Invasive Species: The introduction of the brown tree snake to the island of Guam has caused significant harm to the native bird populations. The snake preys on bird eggs, leading to dramatic declines in bird species. The lack of natural predators for the snake on Guam allowed its population to explode.
f. Disease: White-Nose Syndrome (WNS), caused by a fungal pathogen, has devastated bat populations in North America. disrupts bats’ hibernation patterns, depletes their fat reserves, leading to mass mortality. Bats are essential for controlling insect populations, and their decline due to WNS has ecological consequences.
g. Global Trade: The international trade of amphibians for the pet trade has inadvertently introduced the chytrid fungus, Batrachochytrium dendrobatidis, to new regions. This fungus causes chytridiomycosis, a deadly disease that has led to the decline and extinction of numerous amphibian species worldwide.
Provide an explanation of how the Caribbean monk seals exemplifies the loss of marine species.
a. The North Island giant moas were massive flightless birds native to New Zealand.
i. They belonged to a group of large, extinct ratites called moa.
ii. The North Island giant moas were among the largest of these moa species, standing up to 12 feet tall and weighing around 230 kilograms.
iii. They were herbivorous and played a significant ecological role in the New Zealand ecosystem.
iv. However, the arrival of humans to New Zealand, around 800 years ago, led to the rapid decline and eventual extinction of these giant moas.
v. The Maori people, who settled in New Zealand, hunted the moas for their meat, eggs, and feathers.
vi. The moas’ large size and inability to fly made them easy targets.
vii. The combination of overhunting and habitat modification by humans led to a sharp population decline, and the North Island giant moas eventually went extinct around the 15th century.
viii. This loss of a large herbivorous species had cascading effects on the ecosystem, including changes in vegetation and impacts on predator-prey dynamics.
Provide an explanation of how the North Island giant moas exemplifies the loss of terrestrial megafauna
b. The Caribbean monk seal was a species of marine mammal that was once native to the Caribbean Sea and Gulf of Mexico.
i. These seals were the only pinniped species native to the Caribbean region. They were well-adapted to the warm tropical waters and inhabited coastal and island areas, feeding on a variety of marine life.
ii. Human activities, particularly overexploitation and habitat disturbance, led to the rapid decline and eventual extinction of the Caribbean monk seal.
iii. The seals were hunted extensively for their blubber, which was used for oil, and they were often killed due to conflicts with fishing operations. Additionally, coastal development, pollution, and disturbance of their breeding and resting areas contributed to their decline.
iv. The last confirmed sighting of a Caribbean monk seal was in the mid-20th century, and they were declared extinct in 2008.
v. Their loss is a reminder of how human activities can drive marine species to extinction, particularly when species have limited ranges and face multiple threats.
What are the main threats to biodiversity?
a. Habitat Loss: Due to deforestation, urbanization, and land conversion.
b. Pollution: Air, water, and soil pollution harm ecosystems and species.
c. Invasive Species: Non-native species can outcompete native species and disrupt ecosystems.
d. Climate Change: Alters habitats and affects species’ distribution and behavior.
e. Overexploitation: Unsustainable hunting, fishing, and harvesting of species.
f. Disease: Pathogens can devastate species populations, particularly when immunity is low due to reduced genetic diversity.
What is an example of a lost ecosystem in Florida?
a. One example of a lost ecosystem in Florida is the “Florida Everglades Marl Prairie.” The Florida Everglades, a vast and unique wetland ecosystem, once consisted of various habitats, including marl prairies.
b. Marl prairies were open grassy areas with a unique soil composition called “marl,” which is a mix of shell fragments and limestone.
c. However, due to extensive drainage, urban development, agriculture, and alterations of natural water flows, the Florida Everglades, including its marl prairies, has been significantly impacted and degraded over the years.
Explain the loss of mixed dipterocarp forest in Southeast Asia.
a. The loss of mixed dipterocarp forests in Southeast Asia is a significant environmental issue that has been driven by a combination of human activities and natural factors.
i. Human Factors: Logging, Agricultural Expansion, and Infrastructure Development.
ii. Natural Factors: Climate Change, Fire.
Explain the concept of the “biodiversity crisis” and its implications for the environment.
a. The “biodiversity crisis” refers to the rapid and significant decline in biodiversity across the planet.
b. This crisis threatens ecosystems, species survival, and ecosystem services that humans rely on for survival.
Describe the importance of interdisciplinary research in understanding and addressing the biodiversity crisis.
a. Interdisciplinary research involving biology, ecology, climatology, economics, sociology, and policy is essential for understanding the complex factors contributing to the biodiversity crisis and developing effective strategies for mitigation and conservation.
What is meant by “species richness” and “species evenness” in the context of ecological surveys?
a. Species richness refers to the total number of different species present in a given area or ecosystem, while species evenness refers to the relative abundance of each species in relation to one another.
Why is it important to gather evidence of change in species richness and evenness over time?
a. Gathering evidence of change in species richness and evenness is essential because it helps scientists monitor the health of ecosystems and understand the impact of various factors, such as habitat loss, climate change, and pollution, on biodiversity.
What are the potential limitations or challenges associated with repeating ecological surveys?
a. Limitations of repeating surveys include resource constraints, changes in survey methods, and potential changes in the study area’s environmental conditions.
b. Challenges may include ensuring consistent survey protocols and accounting for natural variability.
List 7-8 causes of the current biodiversity crisis.
a. Habitat Destruction
b. Habitat Fragmentation
c. Climate Change
d. Pollution
e. Overexploitation
f. Invasive Species
g. Disease
h. Global Trade
i. Deforestation
j. Habitat Degradation
k. Lack of Connectivity
l. Lack of Protected Areas
m. Population Growth and Urbanization
n. Lack of Public Awareness
o. Land Use Change
- Why is it important to have multiple approaches to biodiversity conservation?
a. Biodiversity is complex and varies across species, ecosystems, and regions.
b. Different species face unique challenges and require tailored strategies for conservation.
c. Multiple approaches ensure a comprehensive conservation effort that addresses various threats and contexts.
- What is in situ conservation, and why is it crucial?
a. In situ conservation involves protecting species within their natural habitats.
b. It’s crucial because it allows species to evolve naturally, maintains intact ecosystems, and supports complex interactions among species.
c. In situ conservation also helps preserve genetic diversity, adaptability, and the ecological roles of species.
- What is ex situ conservation, and why is it necessary?
a. Ex situ conservation involves conserving species outside their natural habitats, often in controlled environments like zoos, botanic gardens, or captive breeding programs.
b. It’s necessary for species that face imminent extinction in the wild or require protection from immediate threats while habitat restoration is underway.
