Inventorying trees of local significance at the SZIE Department of Landscape Protection and Reclamation. Abstract

Átírás

1 Chimica Acta Scientiarum Transylvanica, 25/3, Inventorying trees of local significance at the SZIE Department of Landscape Protection and Reclamation Kató Eszter, Nádasy László Zoltán Szent István University, Faculty of Landscape Architecture and Urbanism, Department of Landscape Protection and Reclamation, 1118 Budapest, Villányi út Abstract In 2015 and 2016, the Department of Landscape Protection and Reclamation of Szent István University (SZIE) has worked on several survey and assessment projects aimed at inventorying the most valuable and significant trees of a certain area. In the autumn of 2015 and 2016, students surveyed the most valuable trees of Deákvár, a district of Vác as part of the Department s practical education. This inventory focused on trees in public areas. The goal was to select and survey individual trees worthy of municipal-level protection, and to prepare documentations necessary for formal protection of these trees. Another such project has been the inventorying of the most valuable trees of District XXII. in Budapest. The goal of this inventory was to integrate the individual trees of locally high importance into the district municipality s registry and building regulation system. This inventory included trees in both public and private properties. The main goal of both projects was to select the most valuable and significant trees of the survey area. In Vác, the assessment criteria were the following: notability in the streetscape, age, rarity of taxon, cultural historical importance and ecological value. The methodology was based on the assessment methodology of Dezső Radó (1997). In the District XXII. of Budapest, our methods were slightly different due to the differences in scale and goals. The primary attribute taken into consideration when selecting the trees was their size and dominance over the streetscape and/or cityscape, with health, rarity and cultural historical significance as secondary criteria. 110

2 Kató E., Nádasy L. Z. In Vác, the project resulted in 6 allées, 2 clumps of trees and 8 individual trees being selected, surveyed in detail and recommended for municipal protection. The inventory of District XXII. includes 821 individual trees. Keywords: tree assessment, landscape protection, urban nature conservation, Vác, Budapest. Introduction In an urban setting, vegetation has a diverse set of ecological, functional, structural and aesthetic roles. Recently, an increasing number of municipalities have realized the importance of urban green surfaces, especially those with woody vegetation, and now they are paying more attention to inventorying and protecting publicly accessible green surfaces and particularly valuable urban trees. In recent years, the Department of Landscape Protection and Reclamation of Szent István University has been working with two different municipalities District XXII. of Budapest and the town of Vác, situated in the Budapest agglomeration in order to identify and inventory the most valuable trees in their respective administrative areas, and to assess their condition, which is key in protecting and maintaining them. The two projects had minor differences in their objectives and methods, but were based upon the same principle: identifying and assessing the most valuable individual trees in the urban landscape. Materials and methods Vác In the autumn months of 2015 and 2016, Landscape Architecture students created an inventory of valuable trees in urban areas of Vác, as part of their biannual workshop practice. The goal of the project was to identify and assess the most valuable individual trees, as well as rows and clumps of trees, and later the preparation of local legal protection measures to ensure their conservation. The project was focusing on trees situated in public areas. In 111

3 Chimica Acta Scientiarum Transylvanica, 25/3, and 2016, the inventory for the area called Vác Deákvár was completed. Identification of valuable trees was a two-step process. First, all significant trees in the area were identified, using a specific set of criteria. The system uses five criteria for significant value: Prominence in streetscape; Considerable age (>60 years); Local cultural significance (based on their age or history); Outstanding ecological significance; Rare taxon. In the first step, all trees that met any of these criteria were identified. In the second step, individual trees that satisfied at least three of the five criteria were selected. These were the trees proposed for legal protection, and only these were assessed in detail. Assessment data forms were assembled based on the method of Dezső Radó [1]. Participants measured the diameter of the trunk and canopy, total height, identified the species (and, if applicable, sub-species taxon) of the tree and described its growth habit. The age of each tree was estimated based on the circumference of the trunk, using the chart of Radó [1]. Afterwards, the surroundings of each tree for example, whether the legal requirement [2] for 2,25 m 2 of pervious paving around the trunk was met, as well as land use and potential threats (power lines or other objects interfering with tree growth) were also assessed. As a result, for each tree, four factors condition of canopy; condition of trunk; viability; maintenance were assessed on a 1 to 5 scale. Budapest, District XXII. In District XXII, situated in Southwest Budapest, the goal of the inventorying project was to identify, register and assess the (approximately) 700 most valuable individual trees in the cityscape. The project area included all trees within the district boundaries, regardless of them being situated on public or private properties. The objective was to identify the individual trees that have the largest positive impact on the cityscape, due to their aesthetic, dendrological or cultural significance. The inventory provides information for the municipality, which helps with decisions regarding the legal and practical aspects of maintenance and conservation efforts. The inventory was completed using a three-step method. The first step was preliminary selection, using aerial photographs provided by the municipality, as well as online satellite images and street view images available on Google Maps [3]. In this phase, the primary selection criterion was the size of canopy. The second step included all the fieldwork: 112

4 Kató E., Nádasy L. Z. based on the trees selected in the first phase, surveyors (Landscape Architecture students and landscape architects) examined the area. Surveyors had the task to visit all trees selected in step 1, assess their actual appearance, their predominance in the surrounding cityscape, and their aesthetic value. Based on their experience, they decided which trees are valuable enough to be included in the inventory. In this phase, some trees that were left out of the preliminary selection for example due to their location or small canopy size, but appeared to be of high value in the field, were added to the inventory as well. Surveyors also completed a detailed assessment form about each valuable tree, collecting similar data as in the Vác project. In the final, third step, based on all the collected data and experience of the field survey, the least valuable individual trees were dropped from the inventory. This ensured that the resulting list was consistent in every aspect. From the beginning, we excluded any trees from the list that were hazardous or in extremely bad condition. We also did not take into consideration any trees located within protected areas or invisible from publicly accessible places. Throughout the process, the relative local significance of each tree was the determinative factor of selection the inventory was assembled based on the prominence of trees in the cityscape, and not just on their physical dimensions. Results Species of valuable trees The complete inventory in Vác includes 6 tree rows, 2 clumps and 8 solitary trees, a total of 191 individual trees, all of which were subsequently proposed for legal protection. In District XXII. of Budapest, a total of 705 individual trees were identified as significant elements of the cityscape. The trees on the Vác list are most commonly London planes (Platanus acerifolia syn. P. x hispanica), Oriental planes (Platanus orientalis), Large-leaved limes (Tilia platyphyllos) or White mulberries (Morus alba). In Southwest Budapest, the most common species in the inventory are Horse-chestnuts (Aesculus hippocastanum), Japanese pagoda trees (Sophora japonica), Walnuts (Juglans regia), Almonds (Prunus dulcis), London 113

5 Chimica Acta Scientiarum Transylvanica, 25/3, Fig. 1. The most common tree species of the two inventories. 1. ábra: A vizsgált területek leggyakoribb fafajai. Fig. 2. Health of trees in Vác. 2. ábra: Faegyedek egészségi állapota Vác. planes, as well as various species from the maple (Acer), lime (Tilia) and poplar (Populus) genera. Both study areas are characterized by the most widely used species in urban settings of the 20 th century, as well as some traditionally cultivated fruit trees: walnuts, almonds and mulberries (Fig. 1). 114

6 Kató E., Nádasy L. Z. Fig. 3. Health of trees in District XXII. of Budapest. 3. ábra: Faegyedek egészségi állapota Budapest, XXII. kerület. Health and condition As described earlier, both projects included the assessment of the general condition and health of each individual valuable tree. In both cases, trees were rated on a 0 to 20 scale, where 20 signified the best possible condition, while trees with a score under 10 are in considerably bad state of health. Even though the method used in Vác allowed for trees with serious health issues to be included in the inventory, only very few of these were actually included (Fig. 2). On the other hand, 55% of all trees were in good or excellent condition (18 to 20 points). Individual trees in noticeably bad condition were excluded from the inventory as a basic principle in the Budapest project area. In addition, the selection method, which placed considerable emphasis on aesthetic value and significance in the cityscape, favored trees in good general condition as well. As a result, the lowest health value of any tree included in the inventory was 12, and only a very small percentage of trees received low scores (Fig. 3). However, it is worth noting that 53% of valuable trees were considered to be in very good or excellent condition (18 to 20 points), which is very similar to the figure in the Vác study area. 115

7 Chimica Acta Scientiarum Transylvanica, 25/3, Discussion In conclusion, even though the two tree inventorying projects of the Department of Landscape Protection and Reclamation had significantly differences in methodology and goals, the results show notable similarities. The list of most common species are similar in both areas- the most widely used urban tree species of the 20th century and traditional fruit trees being represented in high numbers in both cases. The condition of trees show a similar pattern as well, despite the different assessment methods: approximately one half of inventoried trees are in considerably good health. References 1. Radó, D., EU Method for the assessment of rows of trees in built-up and outlying areas [in Hungarian] Bel- és külterületi fasorok EU-módszer szerinti értékelése. Lélegzet. 1999/7 8. Appendix. Budapest. p /2008. (XII. 30.) Government Decree on protection of woody plants. 3. Google Maps and Google Street View [online]. (Last retrieved on 27th August 2016). Helyi jelentőségű faegyedek kataszterezése a SZIE Tájvédelmi Tanszékén 116 Összefoglalás A Szent István Egyetem Tájvédelmi és Tájrehabilitációs Tanszéke 2015-ben és 2016-ban több alkalommal végzett olyan felmérési és értékelési munkát, amelyek az adott terület legértékesebb, kiemelkedő jelentőségű fáinak kataszterezését célozták és 2016 őszén hallgatói gyakorlatok keretein belül Vác - Deákvár területének értékes faegyedeiről készült felmérés, a közterületekre fókuszálva. A munka célja a helyi védelemre érdemes faegyedek kiválasztása, részletes felmérése és védettségük előkészítése volt ban pedig Budapest XXII. kerületének legértékesebb fáiról készült kataszter, abból a célból, hogy a kerületi jelentőségűnek minősített

8 Kató E., Nádasy L. Z. egyedek bekerülhessenek a kerületi önkormányzati nyilvántartásba és építési szabályzatba. A XXII. kerületi felmérésbe köz- és magánterületi faegyedek egyaránt bekerültek. A felmérések mindkét esetben a vizsgált területek legértékesebb faegyedeinek kiválasztását tűzték ki célul. Vácon a fák értékelése során figyelembe vett szempontok (Radó Dezső 1997-es értékelési módszertanán alapulva) az utcaképi jelentőség, a fák kora és fajának ritkasága, kultúrtörténeti jelentősége, valamint ökológiai értéke voltak. A XXII. kerületben az alkalmazott szempontrendszer a léptékhez, illetve az eltérő célokhoz igazodva némileg más volt: elsődlegesen a fák mérete, utca- és településképi jelentősége, másodlagosan pedig egészségi állapotuk, ritkaságuk és kultúrtörténeti jelentőségük alapján lettek kiválasztva a legértékesebb egyedek. Vácott a munka eredményeképp 6 fasor, 2 facsoport és 8 faegyed lett részletesen felmérve és helyi védelemre javasolva. A XXII. kerületben pedig összesen 821 faegyed került kataszterezésre. 117