Apes 1.2 & 1.3 class notes- Biomes: Terrestrial and Aquatic Overview with HIPPCO, Climate Reading, and Sustainability

What is a biome?
- A biome is a large-scale community of organisms defined by its climate (temperature, precipitation), soil, and adaptations of its inhabitants.
What are the main abiotic drivers of terrestrial biomes?
- Key drivers include average annual temperature, average annual precipitation, soil nutrients and depth, and geographical factors like latitude and altitude.
What is permafrost?
- Permafrost is soil that remains frozen most of the year, a key characteristic of some cold biomes.
How are biomes interconnected?
- Biomes are linked through productivity and food chains: plants form the base, supported by soil nutrients, which then support herbivores and predators.
What is the key takeaway about studying biomes?
- Focus on identifying trends and core characteristics rather than memorizing exhaustive biome lists.

How do climate and soil shape biomes?
- Climate (temperature, precipitation) and soil/nutrient availability determine plant communities, which in turn shape animal communities.
What are the predictable patterns created by temperature and precipitation?
- Warmer, wetter areas tend to have different biomass and productivity compared to colder, drier regions.
What are the main latitudinal climate zones?
- These include the Tropics (approximately within $\pm23.5\degree$ of the equator), Temperate zones (between about $\text{23.5\degree}$ and $\text{66.5\degree}$ north and south), and Polar zones (near the poles beyond $\sim66.5\degree$ ).
How do climate factors influence ecosystems?
- Precipitation and temperature affect soil moisture, nutrient cycling, plant growth, animal life, and human land use decisions.
What integrates climate and biodiversity threats?
- Changing climate shifts biome boundaries, alters productivity, and impacts species ranges and survival.

What is a climatograph?
- A climatograph is a graph showing monthly temperature ( $\text{\degree C}$ ) and precipitation (mm or cm) over a year, used for biome identification.
How is a climatograph used to identify a biome?
- By analyzing overall temperature and precipitation patterns, including seasonality, one can infer the characteristic biome (e.g., warm and wet year-round suggests tropical rainforest).

How dynamic are biomes?
- Biomes are constantly changing, with climate change altering species distribution and biome ranges over time.
What are the two basic responses of species to shifting climates?
- Species can either move to a new region within their tolerance range or face local extinction if their current habitat becomes unsuitable.
How do human activities affect biome dynamics?
- Human actions like urbanization, deforestation, agriculture, and fossil fuel use accelerate habitat loss and climate changes, altering global biome distributions.

What does HIPPCO stand for?
- HIPPCO is a mnemonic for Habitat loss, Invasive species, Pollution, Population (human), Climate change, and Overexploitation—major threats to biodiversity.
Why is applying HIPPCO important?
- It helps assess a biome's vulnerability and guides conservation planning.

What are ecotones?
- Ecotones are transitional zones where terrestrial and aquatic biomes meet; wetlands are key examples.
What defines a wetland?
- Wetlands are defined by hydric (water-saturated) soils, the presence of water (permanently or seasonally), and adapted plants that tolerate waterlogged conditions.
What are key ecosystem services provided by wetlands?
- They slow runoff, reduce floods, recharge aquifers, provide diverse habitats, and support recreation and economies.
What are estuaries?
- Estuaries are critical transition zones where freshwater and saltwater mix, known for high biodiversity and as breeding/migration grounds.

What are the two main types of freshwater ecosystems?
- Lakes/ponds and rivers/streams.
What key factors define water quality in aquatic biomes?
- Temperature, dissolved oxygen (DO), pH, salinity, turbidity (water clarity), nutrients, currents, and depth.
How does temperature affect dissolved oxygen in water?
- Warmer water holds less dissolved oxygen than colder water.
Describe the zonation in lakes and ponds.
- Littoral zone: Shallow, nearshore area with abundant light and emergent plants.
- Limnetic zone: Open water where light penetrates, supporting plankton but no rooted plants.
- Profundal zone: Deep water with little or no light, low photosynthetic activity, and lower DO.
- Benthic zone: The bottom region with nutrient-rich sediments, home to invertebrates and detritivores.
Differentiate eutrophic and oligotrophic lakes.
- Eutrophic lakes have high nutrients, leading to high productivity but often low DO; oligotrophic lakes have low nutrients, clear water, and high DO.

What are intertidal zones?
- These are land-sea interfaces where organisms must tolerate both submerged and exposed conditions due to tides, resulting in highly dynamic and diverse habitats.
What defines open ocean and coastal ecosystems?
- They vary significantly with depth, temperature, salinity, currents, and light; biodiversity is often greatest in productive areas with upwelling.
What are salt marshes and mangroves?
- These are salt-tolerant wetlands with unique plant communities that stabilize coastlines and provide habitat, but are vulnerable to sea level rise.

Why are ecosystem services important?
- Biomes provide essential ecosystem services (air, water, soil fertility, climate regulation) that are critical for human survival and well-being.
What is the overall message about biomes and sustainability?
- Understanding biomes, their drivers, and threats helps us take practical conservation actions for a sustainable future.

What is Net Primary Productivity (NPP)?
- NPP is the amount of plant biomass produced, considering gross primary productivity (GPP) and respiration (R), represented by the general relation $NPP = GPP - R$ .