Salix × doniana on Ainsdale Sand Dunes National Nature Reserve

Salix × doniana on Ainsdale Sand Dunes National Nature Reserve,

October 2013

Philip H. Smith, Patricia A. Lockwood & David Mercer

 

The five known bushes of the nationally rare willow hybrid Salix × doniana on Ainsdale Sand Dunes NNR were revisited on the morning of 15th October 2013, having been last surveyed on 1st September 2008. Using tape-measures, the length, breadth and maximum height of the bushes were noted and Grid References checked using a Garmin Etrex GPS unit. Bush areas (in square metres) were estimated by π × r2 where π = 3.14 and r = (l + b)/4. These data are shown in Table 1.

The five original bushes are situated in numbered wet-slacks and were easily refound, all being apparently healthy.  However, 96 West was much smaller than previously noted (0.9m2 as opposed to 14.2m2). This is a small-leaved bush, difficult to differentiate from surrounding Salix repens (Creeping Willow), so its full extent may have been overlooked.

The 100 West bush was also smaller than before, having lost about 15.5% of its area. This may be due to inaccuracies of earlier measurements or to competition from a dense stand of Phalaris arundinacea (Reed Canary-grass) and a large bush of Salix cinerea (Grey Willow); the latter was cut down.

Bush 96 East has grown by 44% while the two adjacent bushes in slack 17 (East and West) show a total net area increase of 5%.  However, a new bush was noted here a few metres to the north of 17 East. Named 17 North, this specimen has similar physical characters to its neighbours and has most probably arisen by vegetative propagation.

While searching slack 100, we discovered a completely new specimen of S. × doniana about 90m from the known individual. This was named 100 Central, the original bush being 100 West. Surrounded by dense Salix repens, this specimen (area13.2m2) has rather small leaves but is otherwise typical with bright orange-red stems.

Overall, the total area of the NNR bushes has increased by 9.8% from 284.6 to 312.5m2 over a five-year period (Table 1).

The two additional bushes discovered during the survey increases the total number for the Sefton Coast to 32. Unfortunately, the sex of these individuals could not be determined as catkins are not present in October. In the rest of Britain and Ireland, the only other currently known bushes of this willow hybrid are two in Scotland and one (or a small group) in Norfolk.

 

Table 1. Locations and dimensions of Salix × doniana bushes on Ainsdale NNR

* = new bush recorded in 2013

Slack &

position

Grid Reference

Sex

Max. ht

(2008)

Max. ht.

(2013)

Area (m2)

(2008)

Area (m2)

(2013)

100 West

SD2956911451

f

1.26

1.48

67.2

56.8

100 Central*

SD2965811473

 

 

0.96

 

13.2

96 East

SD2959911222

f

1.9

1.8

21.7

31.2

96 West

SD2958911221

f

0.93

0.8

14.2

0.9

17 East

SD2885410794

f

0.85

1.2

63.6

60.1

17 West

SD2884310800

f

1.0

0.9

117.9

130.7

17 North*

SD2885410803

 

 

1.3

 

19.6

Total

 

 

 

 

284.6

312.5