Human Impact on the Biosphere

Question 1

What is human appropriation of the land?

Answer 1

The process of converting land for the purposes of human consumption

Question 2

What is the main cause of human appropriation of land today?

Answer 2

Rapid population growth is increasing the demand for food and other agricultural products

Question 3

How much global land space is used for human food production?

Answer 3

36-40%

Question 4

What are some of the key areas that have recently been appropriated for human consumption?

Answer 4

South East Asia and India

Question 5

What two impacts does human appropriation have on the biosphere?

Answer 5

Area of natural land decreases and productivity of the soil diminishes

Question 6

How much of the potential productivity of the soils is lost through direct use of biosphere by humans?

Answer 6

25%

Question 7

What is HANPP?

Answer 7

The amount of NPP that the biosphere loses to human appropriation

Question 8

How do you calculate HANPP?

Answer 8

NPP (Harvested) + NPP (Land use induced changes)

Question 9

Who has predicted HANPP will rise?

Answer 9

Krausmann et al., 2013

Question 10

What are some of the biomes that Krausmann et al., 2013 predicts will be most at threat?

Answer 10

Tropical, sub-tropical and Savannah

Question 11

What is arguably the most common way land is appropriated for humans?

Answer 11

Deforestation

Question 12

What happened under the coalition government regarding deforestation proposals?

Answer 12

They wanted to privatise the woodlands of the UK, however, public criticism surrounding this scheme reversed it

Question 13

What is fragmentation?

Answer 13

The process of dividing up the landscape, usually due to agricultural territories

Question 14

What effect does fragmentation have upon habitats and why?

Answer 14

Fragmentation therefore divides habitats in to smaller ones which, linking to island biogeography, means that they will be less resilient and biodiverse

Question 15

What impact has fragmentation had on the species numbers in the world?

Answer 15

There has been the extinction of 59 species since the 1600s, despite the natural extinction rate being 1 specie every 400 years.

Question 16

What happened to the Passenger Pigeon?

Answer 16

This was at one point the most common species of bird on the planet, however, following increased human appropriation, especially during the 1950s, their habitats and subsequently numbers have declined so that 75% have bee lost which has only happened 5 times in geological history

Question 17

What can be a significant contributor/source of extinction within ecosystems?

Answer 17

The loss of a keystone or pollinator species that acts as the foundation or core to a system and so if it is lost then a lot of other related species will too.

Question 18

What effect is climate change having upon phytoplankton and Cornwall?

Answer 18

The warmer temperatures in Cornwall are attracting larger blooms of phytoplankton that sharks are following

Question 19

What effect is climate change having upon British Sea birds?

Answer 19

They are having to change their diet as their original diet source is no longer found in the same habitat. This means they are having to feed upon sand eels which are not as nutritious and can choke young chicks

Question 20

What effect is climate change having upon polar bears?

Answer 20

The warmer temperatures in the poles is causing the ice habitat to crumble forcing their numbers to decline

Question 21

What is a climatic envelope?

Answer 21

Areas that are suitable for a specific species

Question 22

What effect may climate change have upon these climatic envelopes as the species tailored to them?

Answer 22

It may cause these envelopes to move or change in shape (bigger or smaller) which the species within them may not be able to move as fast as or may encounter scarce resources or new predators.

Question 23

What is the possible extinction rate of certain species by 2050?

Answer 23

38-52%

Question 24

How may fragmentation influence the impacts of climatic envelopes changing?

Answer 24

It may inhibit species abilities to migrate with the climatic envelopes

Question 25

How is increased carbon impacting upon the oceans?

Answer 25

It is altering the carbonate ratios which affect the erosion and growth rates of habitats (especially coral reefs)

Question 26

What is the significant threshold for carbon parts per million in the oceans that will cause erosion>growth?

Answer 26

480ppm (We recently passed 400ppm)

Question 27

What two things are dramatically affecting the nitrogen cycle?

Answer 27

Fertilisers use and the Haber-Bosch process.

Question 28

What problems is altering the nitrogen cycle having upon the soils and other things?

Answer 28

There is an overconcentration of nitrogen oxides which is altering the cycle's functionality and furthermore is leaking in to water supply which is toxic

Question 29

What happens when nitrogen oxides dissolve in rainwater and where is this impact visible?

Answer 29

They produce a highly acidic solution that causes acid rain and the impacts of this can be seen in Swedish forests.

Question 30

What can happen if the nitrate and phosphorus concentrations within freshwater reach a certain point?

Answer 30

They can produce algae and weedy plants that are capable of outcompeting other species. Furthermore the decomposition process uses oxygen which can deprive those other plants of oxygen (antioxidation)

Question 31

How does changing levels of nitrogen and phosphorus impact upon species competition and biodiversity?

Answer 31

Species that are more resilient and versatile such as grass will be able to overcome dramatic changes where others wont meaning that there presence increases at the expense of decreases in others