Food production and water quality
Sediment concentrations in stream water during periods of heavy rain increase with distance down the catchment with increasing arable influence, lowest concentrations being present at the head of the catchment in the ancient semi-natural woodland, with only a small increase as the stream passes through pasture. This is consistent with our previous studies comparing the influence of different land cover types on water quality - production of food from arable land has a greater impact on water quality (and ecology and flow) than does food production from pasture. See the post for 26 July for the role of wildlife in addressing this issue. At base flow in summer, soluble reactive phosphorus concentrations are also low in the upper part of the catchment but increase considerably where the stream passes rural houses because of the influence of septic tanks. The phosphorus concentration is lower at the base of the catchment as dilution and biological activity improve water quality lower down the stream.
|Turbidity (reflecting sediment concentrations) during winter rain, and soluble reactive phosphorus during base flow in summer, at six sampling points along the School Farm stream.|
Non-crop habitats as sources of crop pest predators
|Carabid beetles captured using emergence traps in wood edge and hedge|
Further examples of interactions between wildlife and food production can be found in the original article and others will appear on this blog in due course.
*Stoate, C. 2014. Wildlife has its uses – managing farmland for ecosystem services. British Wildlife 25: 154-160