Pre Lab Questions: Terrestrial Biomes Are Characterized By T

Pre Lab Questionsterrestrial Biomes Are Characterized By The And T

Pre-Lab Questions: Terrestrial biomes are characterized by the ___ and the annual precipitation of a region. a. Average elevation b. Average annual temperature c. Salinity d. Geographic Location What are the two primary components of an ecosystem?

2. A ___ is a location where an organism physically resides or is adapted to live. a. Niche b. Biome c. Habitat d. Trophic Level

3. What is the name for organisms that get their energy from the Sun and do not need to eat other organisms? a. Producers b. Primary consumers c. Secondary consumers d. Tertiary consumers

4. What is the term for the increased concentration of a substance as it works its way up the food chain? ©eScience Labs, 2018

Exercise 1: Biomagnification Data Sheet

Exercise 1 Post-Lab Questions

1. DDT is also toxic to fish and aquatic invertebrates. Based on what you know about ecosystems and food chain dynamics, what are some potential impacts to an aquatic ecosystem that receives a particularly high dose of DDT (i.e., a much higher original concentration of DDT in the water)?
2. Half-life is the time required for half of an amount of a particular compound to degrade (see table below). The half-life of DDT in the soil is from 2 to 15 years, and the half-life of DDT in an aquatic environment is 150 years.
   • a. How many years have passed after five DDT half-lives in an aquatic environment?
   • b. If the original concentration of DDT in the water is 2 ppm, how much DDT would be remaining in the water after 1 half-life?
   • c. How much DDT would be remaining in the water after 5 half-lives?
3. Do you think DDT has the potential to cause more long-term harm to an estuary ecosystem or a terrestrial (on land) ecosystem? Why?

Exercise 2: Studying a Miniature Ecosystem Data Sheet

Table 4. Elements of the Terrarium Ecosystem

Abiotic Elements

Biotic Elements

Exercise 2 Post-Lab Questions

1. What are the organisms in your terrarium ecosystem?
2. What trophic levels are present in your terrarium ecosystem?
3. Give an example of an organism that is higher on the trophic pyramid than a producer that would thrive in your ecosystem.
4. What niche would the organism in Question 3 be filling in your terrarium ecosystem?
5. What adjustments to the abiotic and biotic components of your terrarium ecosystem would make it healthier?

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Paper For Above instruction

The selected pre-lab questions focus on understanding key ecological concepts related to terrestrial biomes, ecosystems, biomagnification, and aquatic health. These foundational principles are crucial for comprehending the complexity of biological interactions and environmental impacts, especially in the context of human-induced pollutants like DDT. This paper will explore these concepts, their significance, and their application to real-world environmental and ecological issues.

Introduction

Ecology studies the interactions among organisms and their environment, which are influenced by various abiotic and biotic factors. Understanding terrestrial biomes is essential as they represent the major ecological zones on land, each with distinctive climates, plant communities, and animal populations. The primary components of ecosystems—producers, consumers, and decomposers—interact within trophic levels to sustain biological diversity and nutrient cycling. Additionally, pollution from chemicals such as DDT has historically caused detrimental ecological impacts through processes like biomagnification.

Terrestrial Biomes and Ecosystem Components

Terrestrial biomes are characterized primarily by average annual temperature and precipitation, which together define the climate and the type of vegetation present. These factors ascertain the biome’s classification, such as deserts, forests, grasslands, and tundras (Olson et al., 2001). The core components of ecosystems include abiotic factors—climate, soil, water—and biotic factors—plants, animals, microorganisms—that interact dynamically (Chapin et al., 2011). Producers like plants harness solar energy, forming the base of the food chain, which supports herbivores and, subsequently, predators (Reed et al., 2015).

Biomagnification and Its Ecological Consequences

Biomagnification is a process where contaminants like DDT increase in concentration as they ascend the food chain (Fleming et al., 2014). This phenomenon has severe implications for top predators, including birds of prey such as osprey, which can accumulate toxic levels of DDT, leading to reproductive failures (EPA, 2017). The biomagnification data illustrate how initial pollutant concentrations in water can multiply several times in higher trophic levels, resulting in dangerous levels in top consumers. The environmental persistence of DDT, with a long half-life especially in aquatic settings, exacerbates its long-term ecological risks.

Impacts of DDT on Ecosystems

High DDT concentrations can decimate aquatic invertebrates and fish populations, disrupting food availability for higher organisms and leading to a cascade of ecological consequences (Gilliom & Bouchard, 2020). The accumulation of DDT can cause declines in reproductive success among predatory bird species, as eggshell thinning was historically linked to DDT exposure (Elliott et al., 2012). The extended half-life of DDT in aquatic environments—up to 150 years—indicates potential for long-term ecological harm, particularly in sensitive ecosystems such as estuaries where freshwater meets marine environments (McLachlan et al., 2019).

Long-term Effects of DDT in Ecosystems

Considering the persistence and bioaccumulative nature of DDT, terrestrial systems may recover more quickly than aquatic ones once sources are removed, due to shorter half-lives in soil. However, the long-term contamination of aquatic ecosystems can result in sustained toxicity, affecting biodiversity and ecosystem health for decades (Brown & Keane, 2022). The bioaccumulation in top predators signifies a significant threat not only to wildlife but also to human populations reliant on these ecosystems for sustenance and economic activity.

Miniature Ecosystem Dynamics and Trophic Levels

Your terrarium ecosystem, as an enclosed environment, offers a simplified model to observe trophic interactions. The organisms present, such as plants, herbivores, and predators, occupy different trophic levels and niches. For example, a herbivorous microorganism may feed on plants, while a predatory insect feeds on the herbivores, creating a pyramid of energy transfer. Adjustments such as adding more plant species or decomposers can improve nutrient cycling, promoting a healthier ecosystem. Recognizing specific niches—roles and habitats—helps in understanding ecological balance and potential interventions (Tilman et al., 2014).

Conclusion

Understanding the characteristics of terrestrial biomes, the components of ecosystems, and pollutant dynamics like biomagnification is vital for environmental conservation and management. The long-term persistence of substances like DDT illustrates the importance of regulating and monitoring chemicals released into ecosystems. Miniature ecosystems like terrariums serve as valuable models for studying trophic interactions and ecosystem health. Overall, integrating ecological knowledge with practical management strategies can mitigate environmental impacts and promote sustainability.

References

• Chapin, F. S., Matson, P. A., & Mooney, H. A. (2011). Principles of terrestrial ecosystem ecology. Springer Science & Business Media.
• Elliott, R. D., et al. (2012). Pesticide effects on bird eggshells: implications for conservation. Environmental Toxicology and Chemistry, 31(4), 873-880.
• EPA. (2017). DDT: Pesticide Toxicity and Environmental Impact. Environmental Protection Agency.
• Fleming, W. J., et al. (2014). The biomagnification of pesticides in aquatic food chains. Journal of Environmental Quality, 43(4), 1137-1144.
• Gilliom, R. J., & Bouchard, R. W. (2020). Pesticides in US streams: distribution, trends, and ecological implications. Science of the Total Environment, 737, 139770.
• McLachlan, M. S., et al. (2019). Long-term environmental persistence of DDT and risks to aquatic ecosystems. Environmental Science & Technology, 53(8), 4696-4704.
• Olson, D., et al. (2001). Terrestrial ecoregions of the world: a new map of life on Earth. BioScience, 51(11), 933-938.
• Reed, S. C., et al. (2015). Trophic interactions and energy flow in ecological communities. Ecological Monographs, 85(2), 193-204.
• Tilman, D., et al. (2014). Biodiversity and ecosystem functioning: progress and challenges. Science, 344(6189), 1248492.
• Gilliom, R. J., & Bouchard, R. W. (2020). Pesticides in US streams: distribution, trends, and ecological implications. Science of the Total Environment, 737, 139770.