1. Influence of the spruce bark beetle on the Białowieża Forest

2. Bark Beetle– Ips typographus Family- Curculionidae Order- coleoptera Subfamily- scolitidae
Biology
Bark beetles reproduce in the inner bark, living and dead phloem of trees where they build tunnels in a purpose to mate and lay eggs.
When males find weak tree use pheromones to attract more beetles to the tree.
Two to five weeks after laying eags beetles can move to another tree and repeat the process. It takes 10 weeks to develope a new generation
Three generations can be conducted per year.
Breeding material: weakened spruces 3 age classes.
Rys. Paulina Giedrojć

3. Morphology 4-5, 5 mm long cylindrical , black or brownish-black
4 teeth on each margin side, third tooth is the biggest
The egg is yellowish-white
The larva is white and legless.
The pupa is white.
Rys. Paulina Giedrojć
Rys. Paulina Giedrojć

4. Meaning in economic forests
It causes the exaggerated fall of needles
Perpetrator of bark coming off
Along with other accompanying kinds perpetrator of the secretion of dead trees.
One of the most dangerous vermin of the spruce
Fot. Paulina Giedrojć

5. Natural significance
Providing the nutritional base for organisms leaving on dead wood
Increasing of gaps in the tree stand essential to live plants, mushrooms and lichens
Initiating natural renovating on gaps
Creating new biotypes
Fot. Paulina Giedrojć

6. Gradation
In previous years the Białowieża Forest struggled with gradations of the spruce bark beetle. They fell for years dry and hot.
The spruce has the flat root system what is providing about his low resistance to abiotic factors, i.e.: winds, droughts and frost. The dehydration causes the weakness mother-in-law what base is giving for the bark beetle.
Fot. Karol Fiedoruk

7. Within 60 last years it is 7 gradation
Within 60 last years it is 7 gradation. Every of them is falling for years, when the groundwater level was too low for the spruce. The average length of every gradation is 4 years, a space between them is about 7 years. The longest outbreak lasted 6 years, it is falling for years to The current gradation lasts from
Current gradation caused damage as many as 4000 ha out of ha of trees in the forest is settled by the beetles.
Fot. Karol Fiedoruk
Natural renovating the spruce on the area of the reserve High Bog in the Białowieża Forest

8. Causes of the gradation
In forests water is one of important components, and when she is missing, trees very much are weakened.
It results from examinations conducted by a research institute of Forestry that gradations of the spruce bark beetle are corresponding to dry and warm years.
In case of the spruce the right state of groundwaters is very important, since he is a sensitive kind for changes.
When the summer is dry, and warm winter and without falls, is starting sorting water. If such droughts are repeating itself in the following years for the action fungal diseases and insects are entering.
They are these are favourable conditions for the development for many bark beetles species.

9. The disputes concerning the good of the Forest
With the fastest way to stop the rapid growth of the size of the population of the bark beetle, is of fragment of settled trees and disposal of them from forest.
At present between foresters, but defenders natures last disputes about the need for this radical step. In the Forest he grows (… grew) many spruces which the age crossed 100 years, or which are in the reserve. Activists are struggling for it not to cut out ancient trees, ecosystems which they are creating and scenic advantages. However foresters want to lead to like of fastest natural renovating settled areas by the bark beetle and to cut inhabited trees down.
Fot. Karol Fiedoruk

10. Workmanship Paulina Giedrojć Weronika Kowalczyk Karol Fiedoruk
Technikum Leśne w Białowieży
Kl.2
Sources of informations
Forest Research Institute