L3 - Freshwater Ecosystem Contents Flashcards
What are examples of provisioning ecosystem services
food (freshwater, aquaculture), fibre and fuel, medicine, handicraft and construction materials, biochemicals and genetic materials
what are examples of supporting ecosystem services
primary production, photosynthesis, soil formation and nutrient cycling
what are examples of regulating ecosystem services
water purification
flood regulation
nutrient cycling
climate regulation
pollination
effluent disposal
what are examples of cultural ecosystem services
recreational
spiritual
educational
aesthetic values
what is the largest component of the hydrosphere
oceans
volume = 1322 million km3
what % of continental water is in polar ice caps and glaciers
54.57%
what % of continental water is in exchangeable groundwater
44.85%
what organisms are categorised as plankton
floating organisms whose movement depends on currents, such as phytoplankton and zooplankton
what are nekton organisms
swimming organisms that can navigate at will, like fish, squids and whales
what are neuston organisms
organisms resting or swimming at the water surface, such as beetles
what are benthos organisms
organisms attached to or living on bottom sediments, like insect larvae and worms
what are the main types of freshwater plants based on their growth habits
emergent, floating-leaved, free-floating and submerged plants
what are emergent macrophytes
rooted plants with aerial leaves, such as water lilies, that can remove nutrients like phosphate from water
why are macrophytes important
they act as a substrate for macroinvertebrates, provide food for fish and wildlife and improve water quality
what are benthic macroinvertebrates
organisms inhabiting bottom substrates for part of their lifecycle, essential for aquatic food webs
what is the importance of dissolved oxygen (DO) in water
it is crucial for aerobic organisms and can limit biota in high-temperature or polluted waters
how does temperature affect water in aquatic ecosystems
it influences stratification, mixing, sedimentation and dissolved oxygen levels
why is light important in aquatic ecosystems
it is required for photosynthesis, determines primary production rates and separates photic and aphotic zones
what are the 2 main types of organic matter in aquatic ecosystems
- particulate organic matter (POM)
- Dissolved organic matter (DOM)
what is coarse particulate organic matter (CPOM)?
organic material larger than 1mm such as leaf litter and twigs
what is fine particulate organic matter (FPOM)?
organic material between 0.2 um and 1mm, often broken down from CPOM by macroinvertebrates
What is dissolved organic matter (DOM)?
organic matter smaller than 0.45 um, available for microbial assimilation
what are the characteristics of lentic ecosystems
standing water, often classified by nutrient richness (oligotrophic, mesotrophic and eutrophic)
what are eutrophic lakes
lakes with high nutrient input (N+P), low light penetration and high phytoplankton biomass
what are oligotrophic lakes
lakes with low nutrient input, high light penetration, and low primary productivity
what are lotic ecosystems
running water systems, such as rivers and streams, characterized by continuous and unidirectional flow
how are rivers classified
by length, drainage area and source
what is a wetland
areas of standing water that support aquatic plants and serve as a transition between terrestrial and aquatic ecosystems
why are wetlands important
store carbon
clean water
reduce floods
support biodiversity
provide habitats for wildlife
what challenges threaten wetlands
pollution
agriculture
urbanisation
invasive species
climate change
what international treaty protects wetlands
the Ramsar Convention signed in 1971
