Hello everyone!
For the past few posts, I have been focusing on groundwater remediation so you may be wondering so what exactly is the link between groundwater and biodiversity. You may be thinking isn’t groundwater underground so how can it affect biodiversity. Well, it is possible so stay tuned to find out. Most of this post would be centered around this very well-informed method guide by Brown et al., 2007. So if you are interested, do head over to read some of the sections you are interested in!
In my previous posts, I have already talked about how groundwater is an important source of freshwater for humans however, it is equally as important for the ecosystems and species that rely on them. Rivers and streams depend on groundwater inputs and many wetlands and most lakes are directly connected to groundwater. This is to say, contaminated groundwater would eventually flow into these ecosystems. Just in Oregon, over 130 species 0f conservation concern have been identified as groundwater dependent. Groundwater extraction and contamination would be a critical threat to the environment and biodiversity.
Researchers in Australia have identified three classes of ecosystems that depend upon groundwater (Eamus et al., 2006):
- Ecosystems that depend upon surface expression of groundwater: these include rivers, lakes, wetlands, and springs.
- Above-ground ecosystems that depend upon sub-surface expression of groundwater: also described as ‘phreatophytic ecosystems’ which are vegetation that extend their roots into the saturated zones of unconfined aquifers.
- Aquifer and cave ecosystem
Of course, the above classification is dependent on the hydrogeological setting of the area.
Importance of groundwater to biodiversity:
- Water supply throughout the year or at certain times such as in the dry season. Some examples are:
- Wetlands, such as fens, rely on groundwater for a large proportion of water supply
- Mesic forests, where tree roots near the shallow water table and use groundwater as a source of water
- Water quality or specific water chemistry: Groundwater moving through geological deposits will contain the mineral characteristics which can provide a unique ecosystem for certain flora and fauna.
- Specific temperature conditions: water temperature regimes, either hot or cold, can be maintained by groundwater. This is important for species that have specific temperature requirements.
Now that we are more informed on the diverse function groundwater provides to these various ecosystems, I believe we can all agree now that groundwater has the ability to affect biodiversity. Contaminated groundwater can eventually flow into these ecosystems and more often than not negatively affecting the area. In addition, talking about remediation strategies, if pumping water out is required, it would affect water supply input into these areas leading to drier wetlands, lakes etc. This would then affect the various flora and fauna that rely on these for water supply.
In my next post, I will be talking more about groundwater biodiversity!
That brings me to the end of my post!
See you guys soon!
References
Brown, J., Wyers, A., Aldous, A., & Bach, L. (2007, December). Groundwater and Biodiversity Conservation. Retrieved September 20, 2020, from https://www.conservationgateway.org/ConservationByGeography/NorthAmerica/UnitedStates/oregon/freshwater/Documents/GW_Groundwater%20Methods%20Guide.pdf.
Eamus, D., Froend, R., Loomes, R., Hose, G., & Murray, B. (2006). A functional methodology for determining the groundwater regime needed to maintain the health of groundwater-dependent vegetation. Australian Journal of Botany, 54(2), 97-114. https://doi.org/10.1071/BT05031
