Processionary moth pine tree pest - Thaumetopoea pityocampa

The Precessionary moth (Thaumetopoea pityocampa) is a little bug but a rather major pest to pine forests in southern Europe.  This little critter builds nests (called "tents") in pine trees.  When the larvae are ready that march out of the "tents" in single file to feed on the pine needles.  If there are several tents in a single tree the caterpillars can literally eat very last green needle right off the tree (see images below).  They are called Processionary due to their single file "procession" that can often be found along the ground under the trees.  One curious thing about these processions is that if you injure any of the caterpillars in the line they will instantly all disconnect and go in different directions as if in a panic.  They do this even if you only pick on the very last on in the line and out of sight of those at the front of the line.  If you give them a few minutes however they will get in a new line again.  Whatever you do don´t touch these with your hands as they can cause irritation to the skin.

A "tent" ready for the caterpillars to march out (below).  Sometimes these get so heavy that they fall out of the trees.

The image below is of an emptied tent where they have already gone out and cleaned the green needles of f of the branches.

The image below is of a newly built tent nest.

The next image shows a young pine tree that has been totally cleaned of all green needles.  This can kill the tree but most often just stunts the growth severally.

Here is a close up of how the branches look after the critters have eaten their full.

This is a picture of hope.  A new growth the next year after a tree has been affected.

Some forests are so afflicted by the Thaumetopoea pityocampa moth that they whole forest looses its green color and turns a grew-brown color.

Cherry plum - Prunus cerasifera

The Cherry plum tree (species name: Prunus cerasifera) is a small tree in the plum family native to Europe and Asia.  It is also planted outside of its native range as an ornamental tree that is prized for its brightly colored blossoms in spring and its purple-reddish leaves.  The fruit is a 2-3cm drupe that it edible.

The size and color of the "cherry plums" makes them easily confusable with cherries (thus the name).  The dark leaf color is a very good clue however to indicate that it is not a cherry tree.  A close examination of the drupe will also set it apart from the shape of a cherry.

The Cherry plum is one of those trees that is highly ornamental in both its spring flowering period and its spring to fall period.

I happened across one of these in bloom recently and observed several Monk parakeets feasting on the flower bulbs. (Image below)

The leaves of the Cherry plum are alternate on the branch.  They have a simple ovate shape and a crenate margin (rounded teeth).  One of the distinctive´s of this tree species is the color of its leaves that range from a dark purple-green to a purple-red color.

The image below shows the bark on both young (lower) and mature (upper) trees.

Bay Laurel - Laurus nobilis L.

The Bay laurel tree (species name: Laurus nobilis L.) is the tree that "Bay leaves" (used to give flavor to cooking dishes) come from.  It also goes by the common names "Sweet bay", "True laurel", "Laurel" as well as a few more that I am not aware of.  In this post I have tried to capture the beauty of the Bay laurel´s flowers as well as the general appearance of the tree and its leaves.  The image below is of the newly opening flowers.

 The Bay laurel is one of those trees that has a tendency to become a small dense thicket.  This is due to the fact that it tends to send up multiple stems right from the base.  The trees below are continually cut back but you can still see the active growth of new stems at the base.

The leaves of the Bay laurel occur alternately on the branch and have a simple to Lanceolate shape with a smooth (entire) margin.  One way to identify a Bay laurel is by rubbing the leaf and smelling the sweet aromatic tone that is characteristic of the leaves and the flavor that it gives to cooking.

The flowers of the Bay laurel and a pale yellow color although they tend to fade and brown fairly quickly.

The flowers occur towards the end of the terminal branches interspersed between the last dozen leaves or so.

The following is an old (out of copyright) illustration of the main characteristics of the Bay laurel.

Pollarding of European Ash trees in Spain

The European ash tree (species: Fraxinus excelsior) is commonly used in Spain as a source of firewood using the technique called "pollarding".  Using this method the land owners are able to harvest decent firewood from their trees without killing them.  The methods consists in cutting all the branches off at about 8-10 feet off the ground every few years.  This rather severe pruning back of the tree causes it to maintain a partial juvenile state and as a result these "pollards" tend to live longer than trees of the same species that are not pollarded.  It also causes the trees to grow thicker at the trunk given them a sort of swollen look.  The pollarding does not kill these trees however and a new set of branches grows back to replace the ones that have been cut off.  The new branches tend to be fairly long and straight which makes them useful for poles or fence posts.  Since they branch off fairly close to the base it makes harvesting the next set of branches all the easier.

A similar practice to pollarding is called "coppicing" where the trees are cut off right at the base.  This is used with trees that grow back easily from the stump or roots in the form of new shoots.  Coppiced trees tend to have multiple trunks while pollarded trees will normally have just one thick trunk.