Groundwater-dependent ecosystems

Groundwater-Dependent Ecosystems (or GDEs) are ecosystems that rely upon groundwater for their continued existence. Groundwater is water that has seeped down beneath Earth’s surface and has come to reside within the pore spaces in soil and fractures in rock, this process can create water tables and aquifers, which are large storehouses for groundwater. An ecosystem is a community of living organisms interacting with the nonliving aspects of their environment (such as air, soil, water, and even groundwater). With a few exceptions, the interaction between various ecosystems and their respective groundwater is a vital yet poorly understood relationship, and their management is not nearly as advanced as in-stream ecosystems.

Examining the composition of stable isotopes in the water found in soil, rivers, groundwater, and xylem (or vein systems) of vegetation, using mass spectroscopy, which measures and sort the masses in a sample, along with data on the changes in groundwater depth coupled with the time and vegetative rooting patterns, shows spatial changes over time in the use of groundwater by the vegetation in its respective ecosystem.

A groundwater-dependent ecosystem can also be inferred through plant water use and growth. In areas with high rainfall groundwater reliance can be seen by monitoring the water use made by the plants of the ecosystem in relation to the water storage in the soil of the area. If the use of water in the vegetation exceeds that of the water being stored in the soil it is a strong indication of groundwater utilization. In areas of prolonged drought the continuation of water flow and plant growth are highly indicative of a groundwater reliant area.

...
Wikipedia