A mangrove swamp is a unique coastal wetland habitat characterized by salt-tolerant trees and dense root networks.
Mangrove swamps experience regular tidal flooding, causing the soil to become completely waterlogged. This significantly reduces the amount of oxygen available in the soil. Explain the effect of this waterlogged soil on the root cells of plants that are not adapted to these conditions.
A student investigates the plant species distribution across a protected zone of a mangrove swamp. She uses a quadrat to sample the plants. She lays out two long tape measures at right angles to each other to define the boundaries of the study area, and then uses a random number generator to select coordinates for placing her quadrats. The diagram below shows the position of all her quadrats across the study area.
The study area measured 60 m×60 m60\text{ m} \times 60\text{ m}60 m×60 m. Each quadrat measured 1.0 m×1.0 m1.0\text{ m} \times 1.0\text{ m}1.0 m×1.0 m. Calculate the percentage of the total study area that was sampled by the student. Show your working.
A second student samples the same area by placing six quadrats in a single line close to the water's edge. Evaluate the sampling method of the second student compared to the method of the first student.
Suggest one hazard and its corresponding safety control measure that the students should include in a risk assessment for an investigation in a mangrove swamp.
Mangrove forests are increasingly cleared or drained to make way for aquaculture or urban development. Explain why conservationists are highly motivated to protect and restore these ecosystems.