Students and academics involved in the Arboriculture study programme at the Faculty of Forestry and Wood Technology of Mendel University (FFWT MENDELU) have inspected around six thousand trees in urban areas and across landscapes throughout the Czech Republic over the course of four years to collect data on the sustainability of tree planting in urban agglomerations. The data revealed that post-planting care is essential for trees to reach maturity, but also that there are significant differences across the country in the care given to trees planted in urban and rural areas. The researchers found discrepancies of up to several dozen percent in terms of both the perspective and the mortality of these trees. The survey will continue in the coming years.
Experts from the Department of Forest Conservation and Wildlife Management have offered students in the Arboriculture programme around 15 topics for bachelor’s and master’s theses since 2000, with a unified goal: to locate 400 newly planted trees and gather as much historical data as possible, such as when, by whom, and how the trees were planted, and then evaluate their current condition and compare it with the level of post-planting care.
“One of the goals was to assess the importance of post-planting care. If we take it to the extreme, we looked at whether the tree was planted and then forgotten, left to its own fate, or whether it was properly cared for, watered, regularly pruned, possibly even fertilized, and whether the trunk was protected, and so on. Another aspect we focused on was the mortality and long-term viability of the trees, meaning whether they have the potential to reach maturity. Trees perform their key functions, such as cooling and humidifying the environment, mainly after they grow larger and establish themselves in their new location, which usually takes at least 20 years after planting,” explained Jiří Rozsypálek, the initiative’s lead researcher.
In the case of avenues where proper care was provided, eight out of ten trees survived and had a promising future. In contrast, in avenues without care, six to seven trees were typically either unviable or dead, with only two to three trees being viable.
According to Jiří Rozsypálek, a common and critical mistake in the care of trees planted in landscapes is the failure to recognize that a purchased avenue tree from a nursery is not a finished product: “This is a tree that requires further intensive care, whether it be pruning, watering, or protection against diseases and pests. The crown it has when purchased, which looks nice and green, is what we call a temporary crown, one that I will completely remove within 10 to 15 years of the tree’s life in that location. In cities, we often need trees to have a so-called clear stem height, which is two to four meters,” the arborist pointed out.
For the successful life of a planted tree, arborists emphasize the need for regular formative pruning so the tree can survive in an urban environment long-term without obstructing vehicles, pedestrians, or infrastructure. Given the current climate change, they place equal emphasis on irrigation: “We experience extreme droughts, and trees need to be watered, but not year-round, only during dry periods. It is better to water more heavily but less frequently, meaning it is preferable to pour 100 to 150 litres of water at a two-week interval rather than five litres every two days,” the researcher emphasized.
The FFWT experts presented the collected data on the condition of trees in urban and rural environments this year at the annual meeting of the Partnership Foundation, attended by Minister of the Environment Petr Hladík, representatives of the Nature Conservation Agency, and other organizations. “Up until now, most grant programmes have focused on tree planting. Thanks to the data we were able to collect and present here, we were promised that this practice will begin to change, and that grants will increasingly focus on the care of planted trees,” Rozsypálek concluded.
Contact for further information:
Ing. Jiří Rozsypálek, Ph.D., Department of Forest Conservation and Wildlife Management, FFWT MENDELU, +420 545 134 184, jiri.rozsypalek@mendelu.cz
Featured photo: Inappropriately selected species for planting, dying due to severe infection by the pathogenic fungus Hymenoscyphus fraxineus.