INTRODUCTION

GENERAL INFORMATION

MY OWN OBSERVATIONS

CONCLUSION

General information about Ivy.

Ivy seed takes 8 weeks to germinate & 6 months for recognizable leaves. One year to reach out to tree or wall, & in 2 years would be climbing.(Because of climate warming this process may now have speeded up ) Ivy takes in more carbon dioxide than they give out & use even poor light very efficiently.

Ivy has 2 growth stages.

(1) Where it grows along the ground and up a tree
(2) When it puts on mature foliage etc.

(1)

(2)

The mature foliage continues to grow & put on weight over the years till it has smothered its host completely. This was a fine oak growing in a ditch with 10 interwoven vines ranging from 20-30-40 yrs. Totally enmeshing the tree

How it Grows.

When Ivy is totally wound around the trunk of a tree, its leaves prevent the activation of any dormant buds and can produce a localised humid microclimate which wood- decay organisms enjoy –such a climate may increase the rate of decay on already damaged areas.

June 1999 from the Nature Conservancy on Weeds.

Ivy out competes grasses, herbs &trees, thereby reduces diversity of natural species and is a pest in Europe. Being evergreen it remains active most of the winter.

To Save Tree immediately—sever main ivy stems at base. It takes 1-2yrs for leaves to turn brown and then fall.

Ivy is also a reservoir for bacterial leaf scorch (Xylella Fastidiosa) a harmful plant pathogen that affects a wide variety of trees including elm, oaks & maples.

Ivy has a phenomenal resistance to most toxins.

In the USA where hedera helix is an invasive plant it has got so bad that they have “Ivy Out”parties. see (www.noivyleague.com)

There are two main species of ivy in UK. In the west they are tetraploid, in the east and north diploid.

In her history of ivy written in 1872 by Shirley Hibbert, she writes:-

“In seasons of drought & scarcity of provender, ivy has proved of great value as cattle food:- for horses, cattle, deer & sheep are partial to it. The latter especially so.
Young plants of ivy are killed out by grassy herbage amidst which they began life.
It is the nature of the plant to climb, and as far as we know it climbs for ever!

The next question concerns the welfare of the trees to. which it attaches itself .Does it injure them? Without doubt it does. The clasping stems check the circulation of the sap in the rind of the tree --- the ample leafage into which the climber developes as it ascends robs its supporter of light and air,& at last destructive warfar ensues. In which the usurping ivy becomes the conqueror. It stifles it.”.

Bishop Mont summed up the characteristics of the plant.

“It is a limestone & woodland plant but given to vagrancy & thriving under the most diverse of circumstances.”

John Evelyn the 17th century diarist wrote “ivy is the destruction of many fine trees and should be destroyed at the roots, by digging it up.” He also mentions how ivy was cut for fodder in the winter months of 1680 for live-stock.

In a “Winters Tale” by Shakespear the shepherd complains of the hunters who have broken in upon his flock:- "They have scared away two of my best sheep, which I fear the wolf will sooner find than the master. If anywhere I will find them, tis by the seaside, browsing ivy!"

To see sheep eating out Spurge in Dakota U.S.A. click on

http://magma.nationalgeographic.com/ngm/0503/features5/zoom2.html

“Mares eat oats,
And Does eat oats,
And little lambs eat ivy
A kid'll eat ivy too
Wouldn't you?"

“Ivy climbs up to reach light in order to set flower & fruit. This mature form does not climb, but simply becomes bigger. Ivy prefers a damp cool soil, and a moist & cool environment.—

The impact of ivy includes decrease in native vegetation & loss of biodiversity,& forms a thick canopy preventing sunlight reaching other plants. On trees it covers the meristems (part of plant capable of growth) & thus disrupts tree growth, first on branch tips & then at tree tops.Once up in the crown of tree, loss of tree vigour is evident in a few years, followed by death a few years later. The huge added weight of vines make infested trees susceptible to blow over during storms.

The impact on photosynthesis & growth might well produce parallel damage to the root system, so that perhaps the tree can no longer provide adequate levels of nutrition to the roots.”

Ivy is definitely responding to the higher CO2s in the atmosphere.

Recent research done in Germany has shown that of all the evergreens growing in Europe, ivy responds more rapidly to the CO2 in relationship to mass of plant.

Frost

Ivy used to be severely checked by frost. There have now been a run of mild winters in the UK, and this has no doubt had the effect of increasing the growth of ivy.

In Norway ivy only grows along coastland where there is little frost.

Photo of ivy growing Fresh pale green leaves, grown during Jan 2006 through winter.

Climate Change.

A farmer in Derbyshire has recorded a marked increase in the growing season in recent years which has extended the grazing period.

A farmer in Bucks. Who has kept records since 1995 says there are fewer frosts, warmer & wetter winters and dryer summers. Weather more unpredictable.

Dairy Farmer in Wales. For past few years marked increase in growing season with shortening of winter, and therefore being able to turn out herd earlier, and graze longer.

In his book Trees & Woodland , Oliver Rackham makes the following comment:- “There are always middle-aged trees; it is old trees, and big dead ones, that are rare and precious. Ancient trees are not senile or geriatric; it is a false analogy to suppose that a 500-year-old oak has a life expectancy comparable with that of a 90-year-old man. The Great Storm should have put paid to the myth that these trees are, in general, dying or unstable or dangerous."