(a) Pattern of Rainfall: The graph shows a fluctuating pattern of rainfall over the 30-year period. There are periods of high rainfall (around 900-1000 mm) interspersed with periods of lower rainfall (around 700-800 mm). The rainfall does not show a consistent increasing or decreasing trend. There appears to be a cyclical pattern, with peaks and troughs occurring at irregular intervals.

(b) Possible Reasons for Rainfall Pattern: Two possible reasons for this pattern could be:

• La Niña/El Niño events: These climate patterns can significantly affect rainfall distribution globally. La Niña often brings drier conditions to some regions, while El Niño can bring wetter conditions.
• Prevailing Wind Patterns: Changes in the prevailing wind patterns, which bring moisture to the region, can lead to variations in rainfall. Shifts in the position of the Intertropical Convergence Zone (ITCZ) can also influence rainfall.

(c) Effect on Agriculture: This fluctuating rainfall pattern would have a significant impact on agriculture. Periods of low rainfall would lead to drought conditions, resulting in crop failure and reduced yields. Farmers would need to rely on irrigation, which can be expensive and unsustainable. Conversely, periods of high rainfall could lead to flooding, damaging crops and infrastructure. Farmers would need to adapt their farming practices, potentially choosing drought-resistant crops or implementing water conservation techniques. The uncertainty in rainfall would also make it difficult for farmers to plan their planting and harvesting schedules.

(a) Types of Vegetation: Three different types of vegetation visible in the image are likely to be:

• Emergent Layer: The tallest trees, visible as isolated crowns above the main canopy.
• Canopy Layer: The dense, continuous layer of treetops that forms the majority of the rainforest's vegetation.
• Understory Layer: The lower layer of shrubs, saplings, and smaller trees that receive less sunlight.

(b) Benefits of Canopy Structure: The dense canopy structure of a tropical rainforest is highly beneficial to the ecosystem.

• Shade and Humidity: The canopy provides shade, reducing evaporation and maintaining high humidity levels within the rainforest. This is crucial for the survival of many rainforest species.
• Habitat and Food Source: The canopy provides a habitat for a vast array of animals, including monkeys, birds, and insects. It also serves as a food source for these animals.
• Carbon Storage: The rainforest canopy stores a significant amount of carbon, helping to regulate the global climate.

(c) Human Activities Contributing to Deforestation: Two human activities that contribute to deforestation in tropical rainforests are:

• Logging: The harvesting of timber for commercial purposes is a major driver of deforestation. Large areas of rainforest are cleared to make way for logging operations.
• Agriculture: The expansion of agriculture, particularly cattle ranching and palm oil plantations, is a significant cause of deforestation. Rainforests are cleared to create pastureland and farmland.

A student could plan a fieldwork investigation to investigate the relationship between altitude and temperature by choosing a location with a significant altitude difference, such as a mountain range or a series of hills. Planning would involve the following steps:

• Location Selection: Choosing a location with a clear altitudinal gradient and accessible paths. Consider safety and accessibility.
• Method Selection: The student could use a thermometer to measure air temperature at different altitudes. They could take readings at regular intervals (e.g., every 100m) along a chosen route. They could also use a compass and map to accurately record the altitude of each measurement.
• Data Collection: The student would record the altitude (using a map and compass) and the air temperature (using a thermometer) for each measurement. They would repeat the measurements at different times of day to account for variations in temperature.
• Data Recording: The student would create a table to record their data. This table would include columns for altitude, temperature, date, and time.
• Risk Assessment: The student would identify potential risks (e.g., weather, terrain) and implement safety measures.