Wildlife Trust Derbyshire Wildlife Trust
East Mill, Bridge Foot, Belper, Derbyshire, DE56 1XH
Tel: 01773 881188 Fax: 01773 821826
E-mail: enquiries@derbyshirewt.co.uk

Starflower Way Pond

Starflower Way (Mickleover)



Derbyshire Wildlife Trust
East Mill
Bridgefoot
Belper
Derbyshire
DE56 1XH
A report for the Wild About Ponds Project
Prepared by Trevor Taylor
Local Wildlife Sites Officer (Planning)
Derbyshire Wildlife Trust

November 2010

Protecting Wildlife for the future

Regisered charity no. 222212
DWT is a company registered in England and Wales
with the Company Number 715675

Starflower Way Pond, Mickleover

Background

Derbyshire Wildlife Trust was commissioned to survey the pond as part of the Wild About Ponds Project and provide management recommendations based upon the findings of the survey.

Map 1 shows the location of the pond although it has to be recognised that since the preparation of the map the pond has been largely enclosed within substantial housing development. The pond is an old field pond which has been retained within the recent housing development to the west of Station Road in Mickleover. The pond provides no functional use in terms of flood alleviation but is set behind an ornamental fence with potential to provide aesthetic appeal and well as provide biodiversity benefits. The pond is still under the ownership of Miller Homes but will eventually transfer to Derby City Council Parks Department.

The pond was surveyed as part of the 2004/5 Derby City Pond Survey and was also the subject of survey work for great crested newt in association with the surrounding housing development during the same period. The results of the survey identified the presence of breeding Common Frog but no species of newts were found.

The pond has always been considered to be a temporary, seasonal water body which Starflower Way (Mickleover) regularly dries out during the summer months.

During the period 2008/9 it was noted that the pond had become dominated by Floating Sweet-grass, Glyceria fluitans, resulting in the presence of very little open water with the exception of a small area at the foot of the mature oak tree which stands on the northern bank of the pond. The extensive and luxuriant sward of Glyceria also resulted in the accelerated drying out of the pond during the late spring/early summer months.

Attempts were made by the Derby City Pond Wardens Association to clear the Glyceria by hand during February 2009 but it was found to be too well-established to have any noticeable effect.

Survey objectives

The aim of the survey was to gather ecological information using the PSYM methodology in order to determine the overall ecological quality of the pond and inform management recommendations to enhance the biodiversity value.

Methodology

The survey followed the standard survey methodology known as PSYM developed by Pond Action (now Pond Conservation) and the Environment Agency. PSYM, the Predictive System for Multimetrics, (pronounced sim) was developed to provide a standard method for assessing the biological qualities of still waters in England and Wales.

The method uses a number of aquatic plant and invertebrate measures (known as metrics) which are combined together and fed into a computer model, along with basic environmental and location data, to obtain a single value which represents the waterbody’s overall quality status.

The following information was gathered for the pond:

Calculating the pond metrics

The data collected from the surveys are used to calculate three plant metrics and three invertebrate metrics.


1. Number of submerged and emergent plant species

This is simply the number of submerged plant species plus the number of emergent plant species. The calculation does not include the number of floating-leaved species present. This is because the pond data suggest that the number of floating-leaved plants occurring at a site does not decline significantly with increasing degradation. The metric is therefore improved by omitting this plant group.

2. Trophic Ranking Score (TRS)

TRS is a measure of the average trophic rank for the pond. This is calculated by assigning each plant species with a trophic score based on its affinity to waters of a particular nutrient status. The trophic scores vary between 2.5 (dystrophic, i.e. very nutrient poor conditions) and eutrophic, i.e. nutrient rich conditions).

Unfortunately, not all plants have trophic scores. This situation has arisen because the current TRS values for standing waters (Palmer et al., 1992) are based only on analysis of lake data, and many plant species which are common in ponds occurred at too low a frequency in lakes to give them a score. Also, some plant species exhibit little nutrient preference.

The TRS value for a site is calculated as follows:

  1. The trophic scores from each plant species present at the site are summed together.
  2. The summed score is divided by the total number of plant species which have a trophic ranking score to give the TRS.
3. Uncommon Species Index

Uncommon species are those which have a rarity score of 2 or more. The number of these species is simply summed to give the number of uncommon species.

Uncommon species refers to species which can be best described as "local", "nationally scarce" or "Red Data Book". The rarity status values for Scarce and Red Data Book species are based on existing definitions derived from the Red data Books and other authorities. The definition of "local" has been used to define species which are not uniformly common and widespread in Britain: with plants this refers specifically to species recorded from between 100 and 700 10 x 10 km squares in England, Wales and Scotland.

4. Average Score per Taxon (ASPT)

The ASPT is calculated by summing the BMWP scores for all taxa present at the site and dividing by the total number of BMWP taxa present.

BMWP (Biological Monitoring Working Party) scores are assigned to taxa depending on their known tolerance to organic pollution, a higher score indicating lower tolerance. The scores were defined by Maitland in 1977.

5. Number of dragonfly and alderfly families.

This metric is the sum of the number of dragonfly (Odonata) and alderfly (Megaloptera) families.

6. Number of beetle families

This metric is the sum of the number of beetle (Coleoptera) families present at the site. The metric has a relationship with bank quality as well as water quality.

Results

The pond was surveyed using the PSYM methodology enabling an assessment of its biological quality to be made together with a comparison with other ponds in the area.

The PSYM scores are placed in four categories which reflect the ecological quality of the pond:

0-25% is very poor, 26-50% is poor, 51-75% is fair, and 76-100% is good

Site and sample details

Grid reference: SK 30633 36033

Site Name: Starflower Way Pond     Code No: TN1

Location: off Starflower Way, Mickleover Derby

Owner/site access details: Miller Homes - access available

Survey Date: 30th August 2009Surveyor: Trevor Taylor (Derbyshire Wildlife Trust)

Environmental Data

Altitude: (m)93m aslpH:7.00
Shade: % pond overhung:8%% emergent plant cover95%
Inflow (absent = 0, present = 1):0Pond area (m2)333m2
% of pond margin grazed:0

Pond base: categories into one of three groups; 1=0%-32%, 2=33%-66%, 3=67%-100%)

Clay/silt:3Sand, gravel, cobbles:1Bed rock:1
Peat1Other1

Emergent plants Rarity Score Trophic Ranking Score
 
Alopecurus geniculatus, Marsh Foxtail 1 -
Apium nodiflorum, Fool's Watercress 1 10
Epilobium hirsutum, Great Willowherb 1 -
Glyceria fluitans, Floating Sweet-grass 1 -
Juncus effusus, Soft Rush 1 -
Juncus inflexus, Hard Rush 1 -
Ranunculus sceleratus, Celery-leaved Buttercup 1 10
Solanum dulcamara, Bittersweet 1 10
Veronica catenata, Pink Water-Speedwell 2 -
 
Floating-leaved plants
 
Lemna minor, Common Duckweed19

Number of emergent and submergent species - 9
Number of uncommon species (with a rarity score of 2 or more) – 1

Trophic Ranking Score – 9.75

Macroivertebrates

Group 5 taxa (BMWP:5)
Gerridae - Water bug (Water skater)
Corixidae - Water bug (Lesser water Boatman)
Dytiscidae - Water beetle (Diving)
Group 7 taxa (BMWP:3)
Lymnaeidae - Snail - Lymnaea pergra
Glossiphoniidae - Leech - Glossiphonia complanata
Erpobdellidae - Leech - Erobdellia testacea

Total No. of taxa6
Total BMWP Score24
ASPT4.0
No of OM taxa0
No. of Coleopt. taxa1

Index of Biotic Integrity (PSYM Score %) = 33. As such the pond would be considered to be in poor ecological condition.

Survey Results

Pink Water Speedwell

Above: Pink Water Speedwell

The most noticeable feature of the pond is the domination of Floating Sweet-grass, Glyceria fluitans, which covers the majority of the pond surface with the exception of a small area of open water along the northern margin under the shade of the mature Oak tree. It is in this area that the other main aquatic plant species occur, namely Fool’s Water-cress and Pink Water Speedwell. The latter species, until very recently was classed as a Derbyshire Red Data Book plant, but is still regarded as rather uncommon. The southern bank, near to the roadside, is marked by a fringe of Soft Rush and Hard Rush. A single clump of Celery-leaved Buttercup was present in the centre of the pond and Great Willowherb is occasional along with Bittersweet. The lack of submerged aquatic plant species as a result of the dense Glyceria growth is a major factor in the rather poor species diversity in terms of both aquatic plants and invertebrates.


Amphibians

Common Frog was regularly recorded using the pond as a breeding site during the period 2004/2005. Amphibian surveys in association with the surrounding development found no evidence of great crested newt.

A torchlight survey carried out on 23rd April 2010 found 3 female and 1 male smooth newt in the area of open water under the oak tree.

Managemaent recommendations

The main ecological concern with regard to the site is the domination of the pond with Floating weet-grass which has resulted in the presence of very little open water and the accelerated drying out of the pond during the late spring/summer period. This obviously significantly reduces the success rate of breeding amphibians. In addition the lack of submerged aquatic plant species reduces the suitability of the site for aquatic invertebrates which is reflected in the relatively poor PSYM score.

The removal of the majority of Floating Sweet-grass is the primary management objective together with the pruning back of the overhanging Hawthorn shrubs overhanging the western and northern banks in order to minimise the amount of leaf litter entering the pond. Both of these tasks should be carried out during the autumn period, ideally between the months of September to November in order to minimise impacts upon nesting birds and breeding amphibians.

It was determined during efforts by the Derby City Pond Wardens to clear the Glyceria from the pond by hand that the grass had become too well-established for manual clearance to have any noticeable effect.

Subsequently on 20th/21st October 2010, as part of the Wild About Ponds Project, the Glyceria was removed by machine following pruning back of the overhanging Hawthorn shrubs by BTCV. The removed material was deposited on the banks of the pond in order to give any invertebrates the opportunity to move back into the pond and the Hawthorn prunings were used to create habitat piles.

Starflower Way (Mickleover)

Future management should be in the form of annual PSYM and amphibian surveys to monitor the success of the Glyceria removal against the baseline information. The re-establishment of Glyceria should also be closely monitored.

Starflower Way Map