My main mission today was to visit another Hampshire and Isle of Wight wildlife trust reserve, Holmsley gravel pit, to spray some Japanese knot weed with herbicide. Holmsley gravel pit is an old disused gravel pit now flooded and surrounded by willow trees, while some of the lake has some native water plants such as water mint and reedmace, it is unfortunately infested with highly invasive New Zealand pygmy weed. In the past the trust has experimented with various herbicides to try and remove the weed and even tried spraying it with antifreeze, unfortunately it has proved almost indestructible and lingers on at Holmsley.
Holmsley gravel pit. The bright green around the water edge is New Zealand pygmy weed.
The site did have quite a few birds present including 82 teal, 27 lapwing, 3 snipe, a green sandpiper, a little egret and a grey heron. There was also unfortunately a large red-eared terrapin. This species of terrapin is native to North America and must be someones abandoned pet, they are a menace eating fish, insects and even ducklings. Fortunately British summers aren’t quite warm enough for their eggs to hatch or they would be even more of a problem.
Red-eared terrapin and 2 teal.
New Zealand pygmy weed up close
After some searching I managed to find the reported Japanese knot weed and spray it a herbicide which hofefully kill the plant off. Japanese knotweed was introduced into Britain in the 19th century as an ornamental plant. Over time it has become widespread in a range of habitats, including roadsides, riverbanks and derelict buildings. It outcompetes native plants with rapid growth and can smother huge areas very quickly. The weed can grow a metre in a month and can even grow through concrete and tarmac. A 1cm section of rhizome can produce a new plant in 10 days. Rhizome segments can remain dormant in soil for twenty years before producing new plants, so I will definitely be back checking on the plant in the future.
Japanese knot weed
Not a huge amount of news from Blashford lakes, but autumn migration was evident this morning as I counted 17 chiffchaffs in the scrub on the paths to the lapwing and goosander hides this morning and two ravens flew east over Ibsley water at 10.20 this morning. The moth trap held 24 moths of 10 species today including a lunar underwing, an autumnal rustic and a brown spot pinion, a species i am not seen before.
Brown spot pinion moth
Blashford Lakes Nature Reserve 