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Herefordshire Wildlife Trust discover a new species of FROG….


Herefordshire Wildlife Trust discover a new species of FROG….



It all started when Natural England wrote a report that concluded The Sturts required long-term hydrological monitoring…

Report summary

The Sturts is a large are of lowland grassland set in the Wye Valley flood plain in west Herefordshire. It consists of three closely-lying blocks of land each divided by hedges and ditches into a pattern of individual fields. The Topography is essentially flat though small undulations occur across most fields. A number of small ponds occur across the site, most of which are seasonal, drying out in the summer.

The Wildlife trust’s principal management aim for the site is to restore the grassland communities to optimal state. The grassland management regimes have been developed, involving a combination of grazing and hay making. However, there is currently not enough information regarding the hydrological aspects of the site to base decisions on operations such as drainage and maintenance of the existing system of field ditches.

A Hydrological survey is required to provide information about the current water regime that operates on The Sturts. The information is needed in order interpret the current distribution of vegetation types and as a basis for formulating management which will encourage a shift towards the target grassland communities of interest. It should also provide information to describe the maintenance of water level regimes in the ponds, in particular the factors controlling summer drawdown.


Three principal areas of investigation are envisaged, collecting data on:

  •       the existing water table regimes across the site;
  •       the existing pattern of surface water drainage;
  •       the factors controlling water levels in the ponds.
Following the report, in March 2006 the Herefordshire Wildlife Trust commissioned a hydrological survey and recommendations for monitoring to include the positioning of loggers and gauge boards.  The report came back and recommended the Isodaq software and Hydrologic equipment.

In the spring of 2007 the boreholes were drilled and the Isodaq VF1e data loggers with level sensors were installed in December 2007. The Herefordshire Wildlife Trust have been monitoring water levels ever since and are using the result to inform their management of the site.


After 9 years of using our legacy products the VF1e data loggers; the Herefordshire Wildlife Trust have discovered a new species of FROG! The Isodaq Technology FROG data logger. On the 12th July 2016 the old workhorse VF1e units were decommissioned and the new FROG’s installed.




The Trust has a full site management review which is due to be undertaken over the next few months so will be using the data to help with decisions about the network of drainage ditches, ponds and the current regime of hay cutting and grazing carried out on the various parts of the site.


Herefordshire Wildlife Trust


Written by Anjie Stevens

Regional Business Manager

Isodaq Technology

24th August 2016

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