AP Syllabus focus:
‘Ecosystem diversity refers to the variety of component parts and interactions within and among ecosystems.’
Biodiversity is a core ecological concept that describes biological variety at multiple levels. Understanding ecosystem diversity, in particular, helps explain why different places function differently and support different communities over time.
Core concepts: biodiversity and ecosystem diversity
Biodiversity: The variety of life across biological scales, commonly described at the genetic, species, and ecosystem levels.
Biodiversity is not just a species count; it also captures how organisms differ genetically, how many kinds of organisms exist, and how living systems are organised into distinct ecosystems. These levels are connected because changes at one level can influence the others.
Practice Questions
FAQ
They use boundaries based on dominant vegetation, abiotic gradients (e.g., salinity), and process changes (e.g., flooding regime). Boundaries can be gradual “ecotones” rather than sharp lines.
Yes. If abiotic conditions, habitat structure, or process rates differ (productivity, decomposition, nutrient retention), the component interactions differ enough to classify distinct ecosystems.
The number and spatial arrangement of distinct habitat types, often mapped via vegetation, hydrology, and soil layers. Connectivity and patchiness are commonly assessed alongside counts.
At small scales, microhabitats drive “within-ecosystem” diversity; at larger scales, climate and geology drive “among-ecosystem” diversity. Changing the map scale can change how many ecosystems are recognised.
Steep gradients (altitude, moisture, salinity) create multiple abiotic regimes over short distances, producing different producer communities and interaction networks that function as distinct ecosystems.
