Heat, drought and bark burn

Description

Drought is a lack of water in the air and in the soil, which is essential for the existence, development and growth of trees. It manifests itself especially during long-term periods with lack or no precipitation. Dew and fog, which replenish moisture from vertical precipitation, are also of great importance for trees. Groundwater and flood water are the decisive sources of moisture in floodplain forests. Lack of water is most negative at the time of assimilation organs formation and maximum tree growth, which is in April and May, or June but also during the late summer, when reserve substances are forming. The winter drought slows down the growth of trees in the following period. In general, the lack of moisture is manifested mainly on soils that are shallow, strongly skeletal, more aerated, sandy or very heavy, on convex, especially the upper parts of the slopes, on ridges and sunny exposures. A special case is the death of trees at higher altitudes due to physiological drought. It occurs after harsh winters, but with a lack of snow, especially with sudden arrival of spring. In this case, still frozen tree roots are not able to supply the physiologically active above-ground parts of the trees. It should be emphasized that the negative effects of drought on forests are underestimated in forestry. The main reason is that the consequences of drought on trees do not have specific symptoms. Thus, the eventual death of trees is often attributed to secondary harmful factors. Deteriorating drought situation on forests is expected. The reason is the ongoing climate change and the consequent disruption of the natural distribution of precipitation during the individual year seasons.

Endangered trees

The susceptibility of trees to drought is determined by their genetic properties. However, it also depends on local natural conditions. Less-demanding tree species include oaks. Rather resistant species to drought are European hornbeam, European larch, birches and Scots pine. On the other hand, silver fir and Norway spruce are very sensitive species.

Damage localization

Man-established stands in the year of their planting suffer the most from drought, followed by very young and young stands. Drought can also damage young trees planted under canopy of old stands. As for localization, the most severe droughts occur at lower altitudes. At present, due to climate change, drought has become a limiting factor in the suboptimal ecological conditions of individual tree species. Therefore, the optimal growth conditions of tree species are shifted to higher altitudes with more precipitation.

Symptom

The harmful lack of moisture to trees (drought) is manifested mainly physiologically, as wilting of shoots, loss of assimilation organs, tree dieback most often in young growth stages. After a sudden intensive warming at the beginning of the vegetation activity of trees, water deficit in tree body occur, which has an adverse effect on trees. Excessive direct and indirect sunlight causes a damage called \\\"bark burn\\\".

Tree Species: Birch, Beech, Maple, Fir, Spruce

Part of a plant- attacked: Tree trunk, Leaf / Needle, Branch

Pest significance: Very harmful

Pest Category: Other

Invasive Species: No

Present in EU: Yes