ecosystems response to change

Question 1

what happens when the water table falls

Answer 1

– soil dries out
– vegitation unsupported so it dries
– species able to adapt will out compete those who can’t
– establish a new dominant species
which will change the ecosystem composition
– different herbivores will thrive impacting the carnivores that prey on them

Question 2

large autotrophic decline

Answer 2

– erosion due to soil exposure no longer held together by the plants roots
– impact infiltration rates
– increase surface run off
– impact drainage basins
– eroded soil means the land becomes leached of nutrients, depleting the soil store as less litter is being decomposed by bacteria
– soil cannot be established by a secondary succession leading to desertification

Question 3

human changes that affect ecosystems

Answer 3

urban planning
trade
resource use

Question 4

urban planning

Answer 4

fragmentation of habitats and break up of ecosystems - potential decline in species as the population cannot successfully reproduce at rates to ensure their species survival - loss in allele frequency and the increased selective pressures for species to adapt means they’ll become vulnerable to extinction

Question 5

trade

Answer 5

remove keystone species to trade valuable parts of them eg: elephant ivory
affects 24% of terrestrial vertebrates
contributes to the biodiversity crisis
one pangolin is taken from the wild ever five minutes and traded to china where their meat is considered valuable and medicinal
around 7000 species have been trafficked since the 1900s
55 african elephants are killed every day for their ivory

Question 6

resource use

Answer 6

deforestation for timber in the amazon destroys habitats many species rely on for shelter and food
–> some species also require large areas of land to sustain their population numbers such as large migratory whales and orangutangs

Question 7

whaling - resource use

Answer 7

blubber and sperm oil
2.9 million where killed by humans in the 1900s for the whaling industry - sperm whales have not recovered past 1/3 of their pre-whaling population numbers and blue whales have declined by 90% – however restoring these numbers to pre-whaling numbers could capture 1.7 billion tons of CO2 per year due to the whale falls that sequester carbon in the deep ocean sediment - representing 60% of annual carbon sequestration

Question 8

sea grass - carbon capture future

Answer 8

world only flowering plant capable of living in salt water
18% of total ocean carbon storage
nurseries for small fish – support up to 80,000 fish species
carbon harvesting 30x harder than terrestrial autotrophs
– WWF’s plan to repopulate the uk’s coasts with sea grass which has depleted by 92% in the last century
aims to plant 30,000 sq meters (3 football pitches worth)
equivalent to 15% by 2030
partnered with Swansea university to plant 1.2 million seeds across wales

Question 9

orangutans - resource use

Answer 9

keep the rainforest healthy by acting as the largest seed disperser and fragmentation of the Borneo rainforest has lead to a genetic decline and population plateau increasing their vulnerability to extinction
– 50% decline in the last 20 years
highly sensitive species that can only survive in certain ecological conditions – have adapted to walk on the ground due to the deforestation of trees and prey on palm oil trees as a part of their new developed diet – slow breeding species too

Question 10

climate change ecological impacts

Answer 10

temperature increase
melting permafrost

Question 11

temperature increase

Answer 11

change distribution of species - only survive in certain ranges
migratory routes disrupted
– early seasonal rises lead to earlier migrations that wont correlate with the availability of food resources in the final destination and along the route
– the unsynchronized migration and life cycles of prey to predator will devastatingly impact these species
examples: Gwitchin, Canada – rely on caribou migration

Question 12

melting permafrost

Answer 12

glacial and coastal habitats affected
eg: antarctica – ice melting affects penguin populations as the saturated soils induce hypothermia in young chicks
eg: Alaska – Inupiat, Kaktovik melting permafrost affect bone head whale storage which is their food source for the entire year
eg: siberia – topographical degradation of land caused craters to appear (80% homes deformed near Norilsk) and dislodged oil pipes and lead to spillages (Norilsk: may 2020 petrochemical tank spill of 20,000 tons into river)