Ecosystems at Risk - Short Answer Flashcards
Why might an ecosystem be vulnerable? (4)
Biodiversity - Greater the level, the more resilient; Genetic, species, ecosystem diversity
Extent - Those of limited size/fragmented area are most vulnerable
Location - Latitude, distance from sea, altitude; specialised species are most vulnerable
Linkages - The > the level of interdependence, the > its ability to absorb change; e.g. krill is the only primary consumer in polar
Why is it important to manage and protect ecosystems? (6-8)
Heritage value - Historic/ social significance which should be preserved for future generations; e.g. GBR is desingated a WHS by UNESCO
Utility - Economic worth; e.g. GBR contributes $6.4B/year to economy + worth $56B + medicinal purposes + environmental services (C02)
Maintenance of genetic diversity - To find resilient/ special species, < vulnerability e.g. chickpea in Turkey which can survive heat
Intrinsic - Spiritual + aesthetic needs; e.g. Ecotourism in GBR, biodiversity
Need to allow natural change to proceed - Ethical responsibility for evolutionary processes
Recommend contemporary management strategies. (5)
Legislation - Policies/ laws
Exclusion - Excluding human activity
Action - Restoration: Reintroduction; Rehabilitation: replanting trees
Design - Plan an artificial way of minimising impact
Education - Inform people
Recommend a traditional management strategy. (2)
Stewardship - Interdependence, respect, co-existence; e.g. Restrictions on hunting, closed seasons
Examples of fieldwork activities and primary/ secondary sources. (3)
Fieldwork and primary: Measuring water temperature, turbidity, field sketches
Secondary: Environmental impact reports, GIS, environmental/ weather maps
Compare the effect of latitude on the nature of two different ecosystems at risk.
GBR: 8-24’S = warmer temperature better for coral growing, at risk of cyclones
HBITW: 33’S Greater seasonal variation in temp, mangroves adapted to grow 18-26C
Explain how the functioning of one ecosystem at risk that you have studied is affected by biophysical interactions. (5)
Dynamics of weather + climate - Rainfall affects fresh water -> less salinity -> spreads mangroves; Temperature requires 18-26C
Geomorphic + hydrological processes - Weathering adds nutrients; erosion, transport, deposition bring nutrients and build up soil (slow water)
Biogeographical processes - Seagrass stabilises. creates mudflat which allows mangroves to establish
Using an example, describe how nutrient cycling affects ecosystems. (4)
Nitrogen cycle in mangroves allows trees to grow. Small animals eat mangrove leaves, creates detritus, decomposition by nitrogen fixing bacteria into nitrates. Without this, N would be lost, disrupting the functioning of the ecosystem.
Explain how natural stress can contribute to both the resilience and vulnerability of an ecosystem. (6)
HBITW is a dynamic ecosystem impacted by natural stress which contributes to its v&r. Changes in salinity + tidal levels make it vulnerable. Made it more resilient with the grey mangrove excluding 95% + 5% of salt via the root and leaf system. Pneumatophores , adapted roots allow it to survive inundation of saline water.
Outline how ONE example of human-induced stress has affected the functioning of an ecosystem. (2)
Human-induced climate change has led to rapidly rising sea temperatures which led to the 3rd mass bleaching event in 5 years in April 2020, 1/4 GBR suffered severe bleaching, most widespread ever. 1/2 coral lost over last 20 years. Corals eject zooxanthellae losing colour and the coral starving
Describe how the nature and rate of change in ONE ecosystem at risk affect its functioning. (6)
Natural change of COTS epidemics which is thought to be responsible for 40% of coral loss over the last 30 or so years, going through 10m2 of coral per year. Relatively slow rate so can be controlled by culling.
Human impacts such as shipping has a fast rate. Shen Neng 1 ran-aground near Rockhampton in 2010 creating 3km long, 250m wide scar, making some of the area devoid due to toxic antifouling paint
Examine the traditional management strategies in one ecosystem at risk. (4)
Approximately 70 Aboriginal and Torres Strait Islander tribal groups around the GBR, which have been managing resources effectively for over 60,000 years, such as seasonal hunting patterns so they don’t hunt animals during their breeding season such as dugong.
Evaluate two contemporary management strategies in an ecosystem at risk. (6)
Exclusion in the GBR includes marine park zoning. 30% of the park zoned for Marine National Park (no take zone), 28% for habitat protection. Effective as it separates conflicting activities, allowing for inter-generational equity.
Action includes an environmental management charge for tourists which was increased from $6.50 to $7 in April 2020 for management for GBRMPA, along with $1.7 million being spent for daily patrols. Effective in allowing those most prepared to look after the reef.
