Food Systems and Tropical Forests (Potts & Chambers)

The primary concerns for food supply over the next century include the increasing demand for food due to population growth, climate change, and limited resources. These factors threaten food security and sustainable production.

Expanding farmland involves converting new areas, often forests, into agricultural land. This has environmental benefits like increased food production but costs, including deforestation, habitat loss, and soil erosion.

Yield potential refers to the maximum amount of crop that can be produced in a given area under ideal conditions with no limiting factors.

The exploitable yield gap is the difference between the actual yield achieved and the potential yield. Limiting factors like pests, diseases, and lack of nutrients contribute to this gap.

The Green Revolution refers to a period of agricultural advancements in the mid-20th century that led to significant increases in food production through modern technologies, such as high-yielding crop varieties and fertilizers.

Tropical rainforests are dominated by woody plants and trees, creating a complex vertical structure with different layers. These forests exhibit convergent evolution, where unrelated species develop similar adaptations in response to similar environmental conditions.

Epiphytes are plants that grow on other plants for support, but do not take nutrients from them. They benefit from increased light exposure and access to nutrients from rainwater.

Despite heavy rainfall in rainforests, parts of the canopy experience water stress during midday due to high transpiration rates and limited water availability.

Agricultural practices that increased crop yields in the mid-20th century, including high-yielding varieties, fertilizers, pesticides, and irrigation.

A system of agriculture that relies heavily on external inputs (like fertilizers and pesticides) and mechanization to produce high yields, often on monocultures.

A holistic approach to agriculture that focuses on creating sustainable and resilient systems by mimicking natural ecosystems and relying heavily on biodiversity and ecological processes.

Growing two or more different crops together in the same field, often with different growth patterns, to enhance biodiversity, improve resource use, and suppress weeds.

Rotating different crops in a field over time to improve soil health, manage pests, and reduce diseases.

Plants grown between cash crops to protect the soil, improve fertility, and control weeds, often grown during off-seasons.

Vegetated areas along field borders and waterways that provide habitat for wildlife, filter pollutants, and prevent erosion.

The right of people to control their own food systems and production, emphasizing local and sustainable methods.

The trend of increasing species diversity from the poles towards the tropics. This pattern exists across various taxa and ecosystems.

The idea that biodiversity is highest at intermediate levels of disturbance, such as grazing or fire. Low disturbance allows dominant species to outcompete others, while high disturbance reduces diversity.

Tropical forests, despite having poor soils, have tight nutrient cycling. This means nutrients are rapidly recycled within the ecosystem, minimizing losses.

An ecosystem created through human activities, often with a mix of native and non-native species, leading to a novel combination.

Grazing can influence biodiversity in different ways: No grazing allows dominant species to take over, intermediate grazing promotes diversity, intensive rotational grazing can be disruptive.

Grazing can have positive benefits for ecosystems, like promoting biodiversity, controlling weeds, and facilitating fire management.

A sustainable agricultural system includes components like biodiversity, nutrient cycling, soil health, water management, and social equity, working together to ensure long-term productivity.

Sand can impact vegetation in the tropics by affecting nutrient availability, water retention, and soil stability, influencing the types of plants that can thrive.

Coral reefs are found in shallow, tropical or subtropical waters. They are not found in freshwater lakes.

Coral reefs are vital ecosystems, offering food, shelter, and protection for a wide range of marine life.

Tiny algae called zooxanthellae live within coral tissue. Algae provide food through photosynthesis, while coral provides shelter and nutrients.

Coral bleaching occurs when corals expel their symbiotic algae due to stress, leading to a loss of color and eventually death.

Human activities like pollution, overfishing, and climate change threaten coral reef health. These factors lead to habitat destruction, disease, and bleaching.

Ocean acidification is the ongoing decrease in ocean pH due to the absorption of excess carbon dioxide from the atmosphere.

Ocean acidification hinders the ability of marine life to form calcium carbonate shells or skeletons, impacting creatures like oysters, coral, and plankton.

Ocean pH has decreased by about 0.1 units since the pre-industrial era, representing a significant increase in hydrogen ion concentration. This change is linked to global warming and greenhouse gas emissions.