Sunday 10 April 2011

Recolonisation

The area I went to today was Spruce plantation for 50 years, then it was clear-felled about 10 years ago.  The original heath environment has recovered somewhat, leading to a wide diversity of wildlife where there was nothing but a black, arid desert for 50 years.

The area is rich in lichens, mosses and heathers, and the remaining stumps and logs are home to more lichens, fungi and insects.

Bilberry is just flowering now, and this flower has drops of what I presume is nectar forming on the inside:

Bilberry flower
Racomitrium mosses have a very distinctive appearance: each leaf ends in a long, twisted hair that gives the plant an overall pale colouring.

Racomitrium lanuginosum
Peltigera lichens are very leafy in appearance, although their colouring ranges from black to palest grey. This huge (40 cm.) specimen of Rabbit's Paw lichen -Peltigera membranacea - is growing on a dead log. 


Here's a close-up of one or two of the individual 'leaves' (properly called 'thalli'):

Peltigera membranacea
Equisetums (popularly known as Horsetails) are some of our most ancient plants. This immediate area has three species in very close proximity, although I do know of a nearby area with Wood Horsetail which clings onto remnants of its original woodland habitat (which presumably preceded the Spruce plantation).

Marsh Horsetail tends to grow in the fringes of wet areas:

Marsh Horsetail

Whilst Water Horsetail definitely prefers its feet to be very wet:

Water Horsetail

Field Horsetail has separate, pale, fruiting growths, which precede the green non-reproductive shoots:

Field Horsetail

Horsetails reproduce via spores which have hair-like growths attached to them. These hairs are very sensitive to humidity and they expand and contract very rapidly, enabling the spores to move through the undergrowth as if they were walking. 

This next shot is rather interesting:
Bombus bohemicus

It's Bombus bohemicus, one of the parasitic Cuckoo Bumblebees. Bombus bohemicus is parasitic on the white-tailed Bombus lucorum complex and, yet again, timing is critical here. The queen of the host species finds a place for her nest and lays her first batch of worker eggs. The cuckoo bumblebee then invades the nest and kills the original queen before laying her own eggs. The host workers then proceed to feed the cuckoo bees for the rest of the season. I watched this cuckoo bumblebee feeding on nectar and then it proceeded to remove all traces of pollen from its legs (you can see the pollen on the grass in the picture.) Since one of the primary roles that bumblebees perform is pollination, it's clear that adult cuckoo bumblebees are of no benefit to either plants or their hosts.


Another legacy of the original woodland environment is the occasional specimen of Wood Sorrel:
Wood Sorrel
Micromoths are just beginning to make their appearance for the year. This is Grapholita jungiella:

The micromoth Grapholita jungiella
These micros are very active at the moment, and you usually have to be patient enough to follow their very erratic flight in order to see them at rest after they eventually land. 

1 comment:

Emma Springfield said...

As always, you have some fantastic photos today. I am especially interested in the cuckoo bee. I will have to do a little research on it.