Ecosystems and Poverty

I’m involved in a project on developing a PES scheme based on water resources for a high-andean Paramo region at the moment, and am well aware of a complete scarcity of biophysical and socio-economic information in general.  A very welcome contribution to the scientific literature has just come out which looks at the hydrological impacts of pine plantations in Paramo regions compared with natural and cultivated land-uses.  Wouter Buytaert and colleagues monitored streamflow in four different “experimental” catchments with similar climatic conditions but differing land-use mosaics.  They found that the afforested catchment predominantly covered by Pinus patula had a water yield substantially lower than the other catchments (175 mm/yr compared with 506 mm/yr in the neighbouring natural catchment).  Quite a marked reduction.  Perhaps just as surprising is that the cultivated catchment has a water yield in between the other two natural catchments (at 646 mm/yr), indicating little difference in total discharge (incidentally something we are also finding through modeling).  However, flow regulation is affected with some reduction in base-flows from the cultivated catchment, and indeed much more drastic minimum flows in the afforested catchment.  Good to put numbers to the hydrological impacts of these land-uses in Paramo ecosystems, and an important contribution to the discussion on whether trees are good for water.  Those interested in more info on Paramo hydrology can find an excellent review paper here.