Climate Change Class Assignment
Instructions
- What phenomena was responsible for the overall decreased temperatures and increased glacial coverage, thus resulting in the most recent Ice Age?
- The mammoth steppe was a biome dominated by grasses that occurred in the northern parts of Eurasia and North America. What modern biome and location does this video claim most closely resembles this biome?
Group of answer choices
Near-Arctic tundra
Tropical Rainforests like you would find in modern day Brazil
Deserts like the Sahara in Africa
African savannas and/or grasslands
- What scientific term best describes one biome or ecosystem overtaking another biome or ecosystem like what happened when tundra and boreal forests overtook the mammoth steppe? The answer is not found in the video; however, you should know the answer from class.
- Food webs track energy flow through the environment. What is the first trophic level of a food web called? The answer is not found in the video; however, you should know the answer from class.
Group of answer choices
Secondary Consumers
Producers
Primary Consumers
Decomposers & Detritovores
- What was the dominant member of the trophic level from the previous question responsible for the incredible diversity of megafauna (“large animals”) on the mammoth steppe?
- What are the two leading hypotheses about why the mammoth steppe disappeared.
- One fact about nature is that cold air cannot hold onto moisture. That is why your lips and hands get all chapped and dry in the winter months, but not so much in the summertime. Warmer air, on the other hand, can hold more moisture. Eventually, much of the mammoth steppe was replaced by trees which could not thrive their before. What change occurred that allowed trees to expand into the mammoth steppe?
- What is carrying capacity and how did that idea manifest at the end of the mammoth steppe?
- Which fact detracts from the climate change hypothesis making it the less plausible explanation for the disappearance of the mammoth steppe?
Mammoth steppe ecosystems persisted throughout the Pleistocene both when temperatures were warmer and cooler.
There is ample evidence that mammoths and other megafauna grazers overconsumed their food resources and mostly starved to death.
Humans migrated out of Africa towards the end of the Pleistocene and planted trees so they could build homes and make spears.
Mammoth steppe ecosystems appeared and disappeared several times throughout the Pleistocene whenever a new ice age began.
- Describe in 5 to 10 sentences how “ecological naivete” forms the foundation for the overhunting hypothesis for the disappearance of the mammoth steppe biome. Be sure to include how this started a positive feedback loop.
- A trophic cascade is when one species arrival or removal from an ecosystem has an outsized impact on all of the different trophic levels within an ecosystem and, therefore, the ecosystem itself.
Do you agree that humans are a major cause of trophic cascades in the past? How about in more modern times? Defend your response with your own knowledge and experience (I do not want you to do any research outside of this youtube video).
- What did the father-and-son Russian scientists do to see if they could bring back the mammoth steppe biome?
Group of answer choices
Cut down the trees and spread seeds of ancient Arctic grasses into the landscape.
Brought in some hairy horses to hang out.
Cut down all the trees and warmed up the tundra ground enough for grasses to grow.
Increased the amount of water available, but not too much, thus allowing grasses to overtake tundra plants and preventing trees from growing to dominate.
- In 2010, the number of megafaunal grazers was nine – counting the 2 that were already there: moose and caribou. What impact did these animals have on the ecology of the area?
- Answer with a minimum of 3 to 5 sentences: If you were able to vote on supporting a thing like this with public funds, how would you vote and why? Do you think that this work has any value to it besides, as the narrator puts it, “seeing if we can relive the past?” What value (or harm) do you see this experimental area potentially having?
- Why should the persistence of permafrost in the tundra be one of your biggest concerns for humanity?
- What effect to the megafauna have on the persistence (or lack thereof) of Pleistocene Park’s permafrost?
Group of answer choices
Large grazers eat the grass which holds the permafrost in place. Without roots holding it together, the permafrost breaks apart.
Large grazers stomp the snow down during the cold winters exposing the permafrost to relatively colder air temperatures causing it to grow faster.
Large grazers eat the snow during the cold winters exposing the permafrost to relatively warmer air temperatures which cause it to melt faster.
Large grazers poop a lot and their warm “cow pies” heat up the ground in the usually cold winters melting permafrost when it should be frozen.
- A keystone species is a vocabulary term that describes a species with an outsized impact on an ecosystem. Removal of a keystone species could cause a trophic cascade alluded to in a previous question.
It is believed that the mammoth was a keystone species for the mammoth steppe – although the narrator does not use this term. Describe what role a mammoth played in this ecosystem that supports this idea of it being a keystone species.
- How does the narrator and the video compare-and-contrast boreal forests and tropical rain forests?
- So, if de-extinctioning mammoths directly leads to the destruction of boreal forests in exchange for the expansion of grasslands in the near-Arctic (and we could keep humans from hunting them for fun… you know human love to kill stuff – especially “new” stuff), would you support bringing the mammoth back or not? Why? Regardless of your stance, be sure to include some positive AND negative reasons for bringing them back.