Deck 2: Terrestrial Ecosystems and Their Relationship to Cultivating Plants

Question 1

What is meant by a niche in ecosystems?

Answer 1

In an ecosystem we find plants, animals, microorganisms all living in an area along and interacting with the non-living components like sunlight, soil, water, climate, etc.
Though all these are all separate entities, they are connected to each other in one way or the other.
A Niche exists when the available resources are partitioned in such a way that the portions are accessible only to selected species. A niche includes everything required by an organism to flourish in a particular environment.

Question 2

Give two reasons why the United States uses so much energy for its food supply.

Answer 2

Agriculture accounts for only 2% or the US energy use thus, it can make only a minor contribution to energy conservation. But, because it accounts for less than 1% of gross domestic product, it is using more than average energy.
The reasons for this are - the production of fertilizers accounts for nearly half of agricultural energy.
Secondly most of the energy used for our food supply is consumed for transportation, processing, and storage. Besides it is impossible to account for all the energy lost between the farm and the dinner table.

Question 3

Why is it usually easy for weeds to get established among cultivated plants?

Answer 3

In cultivated land or ecosystems there might be one or more species that do not exploit all the available resources. Thus, such niches are available for other plant species to colonize there too. These other species are called as weeds.
When all the plants are of the same type in a cultivated land, all their requirements are similar thus, the competition for nutrition, sunlight are all maximum. But, this is not the case for a weed; it has no competitor and thus can easily flourish in the cultivated land.

Question 4

Although disease parasites often do not directly lull a plant they infect, the plant will often the. Why?

Question 5

What is the beneficial relationship that mycor-rhizae have with plants? That Rhizobium has?

Question 6

What role do saprophytes and detritivores have in ecosystems? When do they become most important in plant cultivation systems?

Question 7

What is a biome?

Question 8

How do global wind patterns affect the creation of the major biomes?

Question 9

What types of plants are found in: tropical rainforest, desert, temperate forests, grasslands and savannas, taiga, tundra?

Question 10

What is a microclimate?

Question 11

Describe two ways cultivating plants has impacted biomes.

Question 12

Of the major biomes, which are the most photo-syntherically productive?

Question 13

Are crop systems usually more or less photosyn-thetically productive than the native plants they replaced?

Question 14

Decide if you think it would be a good idea for countries with tropical rainforests to convert the forests to crop land or sell them foi "carbon credits" instead. Then give the reasons for your decision.

Question 15

What is a harvest index?

Question 16

Briefly describe the parts of an ecosystem.

Question 17

Describe ecosystem succession. In terms of succession, what is the difficulty with maintaining many of our crops?

Question 18

Think about the biome in which you live. How do the plants growing in the landscape of your college or at your home compare to those that would be growing there naturally? What, if anything, has to be do ne to alter the environment so that the landscape plants thrive? How would these practices affect the carbon footprint?

Question 19

How does cultivating crops impact our carbon footprint?

Question 20

What distinguishes the ecosystem created by cultivating plants from natural ecosystems?

Question 21

What is the concept of "carbon credits"?