Conservation: Practice Questions

• a.

  Their high rate of transpiration lowers the overall salinity of surrounding seawater, allowing freshwater larvae to thrive.

• b.

  Their root exudates selectively inhibit all pathogenic bacteria, completely preventing disease in marine fish populations.

• c.

  Their dense prop root systems trap organic sediment for food and create sheltered physical refuges from larger marine predators.

• d.

  Their submerged leaves release large amounts of oxygen into the water column through cellular respiration.

• a.

  Lower sedimentation rates caused nutrient starvation among coral polyps, decreasing total coral cover.

• b.

  Increased sediment runoff smothered live corals and reduced light penetration, leading to coral bleaching and mortality.

• c.

  Sediment particles directly consumed coral polyps via filter feeding, rapidly reducing the live coral population.

• d.

  Sedimentation increased water salinity to levels beyond the physiological tolerance of the reef organisms.

• a.

  It accelerates the uptake of toxic heavy metals, causing immediate calcification of algal cell membranes.

• b.

  It lowers the water temperature dramatically, denaturing all metabolic enzymes in the zooxanthellae.

• c.

  It increases dissolved oxygen levels, causing oxidative damage to algal chloroplasts.

• d.

  It reduces light penetration, decreasing photosynthetic rates and depriving the host corals of essential organic nutrients.

• a.

  The fully protected core zone allows fish stocks to mature and reproduce, producing larvae and adult biomass that 'spill over' into the adjacent buffer zone.

• b.

  The buffer zone completely prevents water from exchanging with the core zone, stopping all disease transmission.

• c.

  The core zone increases fishing pressure outside by attracting all marine species into an enclosed trap.

• d.

  The buffer zone eliminates the natural carbon cycle, allowing permanent storage of all organic carbon in the core.

• a.

  Applying broad-spectrum synthetic pesticides across all logged zones to eliminate wood-boring insects.

• b.

  Clear-felling entire forest sectors followed by establishing fast-growing monoculture rubber plantations.

• c.

  Slash-and-burn clearing on a continuous rotation to promote maximum ash-based nutrient recycling in the soil.

• d.

  Selective logging of mature trees combined with designated reforestation cycles and wildlife corridors.

Write your answer out first, then check it against the worked solution.