An audio broadcast from the environmental science series 'Ecosystems of Tomorrow' discusses recent ecological restoration work in the wetlands of Xochimilco, Mexico:
'Urban expansion and agricultural runoff have long threatened the historic chinampa agricultural systems of Xochimilco. To reverse this decline, agroecologists recently implemented an integrated biological filtration network along traditional canal perimeters. Instead of constructing expensive concrete barriers, the team lined the feeder canals with porous volcanic tezontle stone and planted dense borders of native tule reeds. Water monitoring stations recorded that this specific combination trapped suspended silt and reduced dissolved nitrate concentrations by 42 percent within the first six months. Additionally, these stone-and-reed buffers lowered ambient water temperatures by 2.5 degrees Celsius, creating optimal breeding microclimates for the endemic axolotl population. While regional tourism remains a major source of local municipal revenue, funding for this preliminary phase was provided entirely through a cooperative grant from the National Autonomous University of Mexico and local farming collectives.'
According to the audio report, what specific outcome resulted from lining the canal perimeters with volcanic tezontle stone and native tule reeds?
- AThe replacement of traditional reed beds with reinforced concrete retaining walls
- A 42 percent decrease in dissolved nitrate concentrations within six monthsCevap
- CA major surge in municipal revenue generated through regional tourism expansion
- DA total elimination of agricultural runoff across the entire valley