Microbial atrazine breakdown in a karst groundwater system and its effect on ecosystem energetics.

In the absence of sunlight energy, microbial community survival in subterranean aquifers depends on integrated mechanisms of energy and nutrient scavenging. Because karst aquifers are particularly sensitive to agricultural land use impacts due to rapid and direct hydrologic connections for pollutants to enter the groundwater, we examined the fate of an exogenous pesticide (atrazine) into such an aquifer and its impact on microbial ecosystem function. Atrazine and its degradation product deethylatrazine (DEA) were detected in a fast-flowing karst aquifer underlying atrazine-impacted agricultural land.

Natural and anthropogenic factors affecting the groundwater quality in the Nandong karst underground river system in Yunan, China.

The Nandong Underground River System (NURS) is located in a typical karst agriculture dominated area in the southeast Yunnan Province, China. Groundwater plays an important role for social and economical development in the area. However, with the rapid increase in population and expansion of farm land, groundwater quality has degraded.