Lecture 7: Understanding hydrological ecosystem services 4 Flashcards
Percentage of water arriving at tropical dams that fell as rain on protected areas
Method: For all 29,000 dams calculate the percentage of rainfall draining into them that fell on WDPA2009 polygons upstream.
Result: Indicates the contribution of PA’s to the economic output of those hydro companies. Important for the development of PWS schemes to fund conservation.
Threats to hydrological ecosystem services
Current forest cover
Forest cover change 2005-2010
Current rate is higher than previously thought @16M ha/yr
A water quality issue in areas where forests are declining
A water resources issue in areas where forests are increasing
Land uses: 1. Swidden Agriculture
a.k.a. forest-fallow farming or slash and burn
Indigenous tropical forest agriculture characterized by polyculture
Similar in diversity to native forest itself with little disturbance on the forest ecosystem
Land uses: 2. Monoculture
Predominantly associated with cash crops
Mechanized and input intensive
Increases (short-term) productivity
Lacks sustainability
Low genetic diversity
Increases soil depletion
But it is not only deforestation that affects hydrological ES
Dams - interrupt connectivity of river systems- disrupting fish spawning
Over harvesting of wild resources- especially fish
Ag expansion
Roads and flood control infrastructure
urban and industrial pollution
forest clearing- dinner channelisation- large scale irrigation
Ecosystem Services
Critical to the sustainability of our largely urbanised society though not often considered as people are increasingly disconnected from the production sites of the goods and services essential to life : food, fibre, water, energy and an amenable climate.
Provided by nature but essentially charged (costed) on the basis of conversion and distribution costs, largely ignoring the costs associated with maintaining landscape for sustainable supply of these services by nature (sustainability).
