Today's society, especially in large cities, is increasingly interested in urban greenery. Green areas (parks, orchards, forest parks, alleys) are becoming a natural part of towns and perform several functions. Prague can be proud of the title of one of the greenest cities in the world - tourists are often surprised by the number of gardens and parks, which occupy approximately 3,965 hectares, i.e. about 8% of the city's area.
Along with such landscape elements, the biodiversity of the landscape is growing. The view of today's landscape is often alarming and sometimes richer fauna and flora can be found in urban parks than in the countryside in intensively farmed agricultural landscapes, where the use of pesticides and herbicides significantly reduces biodiversity.
Prague orchards, which are rightly among urban greenery, were in search of a team of scientists from the Faculty of Forestry and Wood Sciences at the CULS. They asked a question how many different species of butterflies, beetles, lichens and other representatives of the animal and plant kingdom are found in these urban orchards and how the representation differs in localities without orchards.
Fruit orchards bring not only a more diverse species composition, but also tasty fruits. Greenery improves the microclimate, reduces wind speed or dampens road noise. These places also have a social function, as people can meet here and spend their free time in a pleasant natural environment.
How will the species composition change after the renewal of an orchard?
The species of interest were plants, lichens, butterflies, beetles and birds. The researchers chose a location near the center of Prague in Třešňovka. This cherry orchard is located at an altitude of 240 to 265 m above sea level, and with an area of ??10 hectares it is the second largest orchard in Prague. The first mention of it dates back to 1945, but it was probably founded in the 19th century. Despite the transformation of the surrounding landscape, where many buildings, roads and other structures have been built, the orchards have not changed much. The biggest transformation came after the Velvet Revolution, when the orchard ceased to fulfill its role and its use was abandoned. It also lost its species composition during this period.
At present, the orchard is owned by the Capital city of Prague. The main wood species include cherry (99%), walnut and pear. Prior to research and the restoration of the cherry orchard, most of the cherries (80%) were overgrown with shrubs and trees, and some parts of the park lost the structure typical of an orchard. During the restoration, a large number of trees were replanted, as a large part of the former trees died; now there is only a fraction of the original mother trees in the orchard (5%).
How did the research go?
First, a list of species of interest with various ecological demands was compiled and their numerical representation in the locality was documented before and after the restoration of the orchard. For example, lichens, which serve as a bioindicator, or butterflies, whose representatives show the occurrence associated with vegetation cover, were selected.
What did the results show?
Prior to the restoration of the orchard, there were 65 species of plants, 25 species of lichens, 17 species of butterflies, 19 species of beetles, 12 species of grasshoppers (crickets, moles) and 18 species of birds in the studied area.
After the restoration of the orchard, there was a noticeable increase in species diversity, as there were 105 plant species, 33 species of lichens, 21 species of butterflies and 27 species of beetles, 14 species of equidae and 16 species of birds.
The results clearly showed a positive change in species composition and an overall positive contribution to biodiversity in the densely populated environment of Prague. In particular, the increase in the number of lichen species indicates an improvement in air quality.
In conclusion, it can be stated that ecosystems of this nature are now a sought-after item and traditional orchards offer great potential for multipurpose use. Restoring similar ecosystems helps to increase landscape biodiversity, restore agroforestry systems and preserve green areas. At the same time, urban areas bring important positive social aspects, as they represent a place where residents can use and undertake various activities there. A place that is used to meet and spend free time in connection with nature.
Jakub Horák et al., Renaissance of a rural artifact in a city with a million people: biodiversity responses to an agro-forestry restoration in a large urban traditional fruit orchard, Urban ecosyst, 2017
doc. Ing. Bc. Jakub Horák, Ph.D.
Mr. Horák works at the Faculty of Forestry and Wood Sciences in Prague as an associate professor at the Department of Forest Protection and Entomology. He is interested in biodiversity and has completed 6 internships abroad.
Prepared by Daniel Švrčula