Population Growth

62. Explain how abiotic factors influence where organisms can live, survive, and reproduce

• Abiotic factors such as temperature, light availability, water, and soil nutrients play critical roles in determining the distribution and abundance of species by affecting their physiological processes and habitat selection.

63. Describe how life history traits (e.g., age at maturity, reproductive strategy, lifespan) are shaped

by ecological conditions.

64. Define r-selected and K-selected species and list their typical characteristics (e.g., lifespan, age

of reproduction, number of offspring).

• r-selected species: generalists

  • Characterized by high reproductive rates.

  • Typically have a short lifespan.

  • Reach reproductive maturity quickly, often within a year.

  • Produce many offspring, but invest little parental care.

• K-selected species: specialists

  • Characterized by lower reproductive rates.

  • Typically have a longer lifespan.

  • Take longer to reach reproductive maturity, often several years.

  • Produce fewer offspring, but invest significant parental care in their upbringing.

66. Define generalist and specialist species, and describe how they differ in resource use and habitat

preference.

• generalists: species that can exploit a wide range of resources and adapt to various habitats, allowing them to thrive in diverse environments; these are the kinds of species that can become invasive and thrive in enviornments outside of their originial habitat

• specialists: species that rely on a specific set of resources and have a narrow habitat preference, which makes them highly adapted to specific environments but more vulnerable to changes in those conditions and more prone to extinction

67. Predict how generalists and specialists respond differently to ecological disturbances and habitat

changes.

• generalists: thrive in ecological disturbances and habitat changes; will take over environments that have been destroyed by things likes natural disasters

• specialists: are often more vulnerable to ecological disturbances and habitat changes as they rely on specific resources or conditions that may be disrupted, leading to a decline in their populations.

68. Define ecological succession and explain how biodiversity builds over time in a disturbed area.

• ecological succession: the process by which the structure of a biological community evolves over time, typically following a disturbance that creates a more favorable environment for colonization by various species. As ecosystems recover, pioneering species often establish themselves first, leading to increased biodiversity over time as they modify the environment, allowing for more complex plant and animal communities to develop.

• generalists will usually populate the are first and then specialists, which rely on a stable environment built by generalists, will populate the area and increase biodiversity

69. Connect life history strategy (r vs. K) to stages of ecological succession.

• During the initial stages of ecological succession, r-strategists, which are species that produce many offspring with low parental investment, tend to dominate due to their adaptability and rapid growth rates in unstable conditions. As the succession progresses and environmental stability increases, K-strategists, which invest more time and resources in raising fewer offspring and thrive in stable ecosystems, begin to establish themselves. This shift from r to K strategies illustrates the changing selective pressures as communities mature, ultimately leading to a more balanced and diverse ecosystem.

70. Define biodiversity and describe what is meant by “variety of life” at three levels of biodiversity:

genetic, species, and ecosystem diversity.

• biodiversity:

  the variety of life in a given ecosystem, encompassing three key levels:

  • Genetic Diversity: Refers to the variation in genes within a particular species, which enables populations to adapt to changing environments and contributes to overall species resilience.

  • Species Diversity: Represents the variety of different species within a habitat, including the number of species (richness) and their relative abundance, which promotes ecosystem stability and function.

  • Ecosystem Diversity: Involves the variety of ecosystems in a certain area, with different habitats and ecological processes, which supports a wider range of species and genetic diversity, ultimately enhancing the resilience of the biosphere.

71. Describe the concept of ecosystem services and why biodiversity matters to humans. Be sure to

list and provide examples for each category of ecosystem services.

• Ecosystem Services: Refers to the benefits that ecosystems provide to humanity, which can be categorized into four main types:

  • Provisioning Services: These are the products obtained from ecosystems, such as food, fresh water, wood, fiber, and genetic resources. Examples include agriculture, fishing, and timber production.

  • Regulating Services: These services help regulate natural processes and include climate regulation, flood control, disease regulation, and water purification. For instance, wetlands filter pollutants from water and forests absorb carbon dioxide, mitigating climate change.

  • Cultural Services: These encompass the non-material benefits people obtain from ecosystems, such as spiritual enrichment, recreational opportunities, and aesthetic experiences. Examples include ecotourism, national parks, and cultural heritage sites.

  • Supporting Services: These are necessary for the production of all other ecosystem services and include nutrient cycling, soil formation, and primary production. Healthy soil and biodiversity support nutrient cycling, which is essential for agriculture.

72. Explain why preserving biodiversity is essential for future drug discovery and innovation.

• By maintaining diverse ecosystems, we ensure a wider range of genetic resources which can lead to the discovery of new medicinal compounds; many of today's pharmaceuticals are derived from natural products, emphasizing the potential for undiscovered therapeutic agents in yet-to-be explored species.

73. Define and explain main causes of biodiversity loss.

• The primary causes of biodiversity loss include habitat destruction due to urbanization and agriculture, climate change affecting species adaptation, pollution from industrial and agricultural runoff, overexploitation of natural resources leading to species depletion, and the introduction of invasive species that disrupt local ecosystems. These factors not only threaten individual species but also compromise ecosystem services that are vital for human wellbeing.

74. Describe the relationship between human health and planetary health, and how they influence

one another.

• Human health and planetary health are interconnected; the degradation of ecosystems can lead to increased exposure to diseases, respiratory issues from air pollution, and food insecurity due to the loss of biodiversity. Conversely, the health of planetary systems, such as clean air, water, and soil, directly affects our ability to lead healthy lives, highlighting the need for sustainable practices that benefit both human communities and the natural environment.

75. Discuss how changes in abiotic conditions and chemical pollution can threaten species and

ecosystem function.

• Changes in abiotic conditions, such as temperature, precipitation, and soil composition, can disrupt species' life cycles and habitats, ultimately leading to population declines or extinction. Chemical pollution from agricultural runoff, industrial discharges, and plastic waste further exacerbates these threats by contaminating water sources, harming aquatic life, and altering nutrient cycles, which can destabilize entire ecosystems and diminish their resilience. Consequently, the interplay between these stressors underscores the urgency for integrated conservation strategies that address both abiotic and biotic factors.