Lecture 7: Understanding hydrological ecosystem services 2

Question 1

Water Funds

Answer 1

Help support protected areas for the ecosystem services that they provide to downstream cities through a type of payments for ecosystem services scheme

Question 2

Key hydrological ecosystem services

Answer 2

Water quantity services
Protected ecosystems do not necessarily generate more rainfall than agricultural land uses.

Protected ecosystems may have higher evapo-transpiration
and thus potentially lower water yields
Thus quantity benefits difficult to prove

Question 3

Key hydrological ecosystem services- water regulation services

Answer 3

Water regulation services
Protected ecosystems do not protect against the most destructive floods
For ‘normal’ events they do encourage more subsurface flow and thus more seasonally regular
flow regimes

Possible benefits especially in highly seasonal environments

Question 4

Key hydrological ecosystem services 2- Water quality (quantity for a purpose)

Answer 4

Water quality services (quantity for a purpose)
Protected ecosystems encourage infiltration leading to lower soil erosion and sedimentation
Unprotected land will tend to have higher inputs of pesticides, herbicides, fertilisers …
Clear benefits of PA’s: generation of higher quality water than non-protected areas

Question 5

Hydrological ecosystem services and relevant processes : interception loss

Answer 5

Canopies intercept rainfall which is then easily accessible for evaporation as interception loss (surface area, aerodynamic roughness)

The greater the leaf area index and the smaller the storms, the more effective

Losses can be 10-20% of rainfall

Question 6

Hydrological ecosystem services and relevant processes : rainfall recycling

Answer 6

Basic physics and models suggest that some 20-30% of rainfall in large basins like the Amazon is recycled from evaporation (mainly interception loss) within the basin
There is little empirical evidence though