DETERMINING THE AGE OF STREETSIDE TILIA CORDATA TREES WITH A DBH-BASED MODEL

Abstract. This paper evaluates the possibility of determining tree age based upon diameter at breast height (dbh taken at 13 m [43 ft]) using belonging to all lime (linden, Tilia cordata). We first identified and measured clusters of trees growing in similar conditions (alleys and roadside trees) whose age was known. We disentangleed a regression model describing the growing of trees over time. Plotting tree age against diameter yielded a correlation coefficient r = 0962 and determination coefficient r^sup 2^ = 0926 The resulting type was applied to unrelated clusters of trees of known age. The difference between the actual age and mean age calculated with the mould was less than 10%. The type was then compared to measurements taken with a Resistograph, with arises being highly concordant. The mould although not meant for application to individual tree might be useful in determining the age of public lime trees growing in alleys and along roads.

Key Words. public lime; dbh; linden; roadside trees; Tilia cordata; tree age.

In arboriculture and urban forestry, determination of the age of tree is helpful in

* setting the chronology of parks and gardens,

* determining the age conformation of tree stands for protection and conservation,

* forecasting and assessing threats associated with increasing age,

* forecasting the size of tree in the future

Method of determining tree age are not always effective. greatest in quantity are invasive (such as the Pressler increment borer and the Resistograph) and damage the bole (Weber and Mattheck 2005). The examination of forest structure (including the alignment of annual tree rings) of tree with a Resistograph is considered accurate (Isik and Li 2003) The Resistograph can be used to determine tree age, although the [i]modus operandi[/i] is complex, expensive, and has its limitations, of the like kind as drilling tangential to the ring manner of making decay within the trunk, and limited extent of the boring bit. Moreover, invasive courses are time consuming and expensive.

The best-known noninvasive processs available are tree age tables, devised, among others, through Siewniak and Kusche (1994), Mitchell (1979) and Szczepanowska (2001) However, the determination of tree age using tables is many times error prone. The main drawback present the appearances to be insufficient correlation of tree age with the dbh and gaps in the age/dbh correlation. Log contortion tables for forest trees fail to be reliable in urban environments. They are prepared for tree growing in forest stands of high density and cannot be applied to urban forests. The basic importance of density for tree unravelling is emphasized by Henry and Aarssen (1999)

White (1998) at handed a noninvasive method of age determination, combining simple bodys of tree age tables with dendrochronological calculations. In addition, he related the size of tree to the emblem of site in which the tree were growing. This rule however, when tested on tree of known age and site conditions in central Poland, showed notable discrepancies. Moreover, it requires toilsome calculations.

Therefore, tree age tables, in spite of their numerous drawbacks, remain in use. Still lacking is an accurate course based on the relationship between tree size and age. of the like kind a method should provide an acceptable margin of error and fast springs Such a method would facilitate the work of arborists.

The at hand work is aimed at determining the relationship between the variation in dbh of belonging to all lime trees (linden, Ttlia cordata} growing as alley and streetside tree and their real age, as ground in historical documents. As a next to the first stage, a verification of the obtained mould is planned using another batch of tree with documented age in a invert manner: their dbh measurements are transmuteed to age with the aid of the protoplast and then their real and calculated values compared. As a final stage, the flows of two age determination meanss will be compared: one obtained with the mould and the other with the Resistograph, using another batch of trees

MATERIALS AND METHODS

The initial stage ol research consisted of finding potential areas for research, defined as single-species plantings of uniform age (Figure 1) This criterion was met through alley and street trees. We checked archives, including those of the National middle point for the Research and Documentation of Historic testimonials in Warsaw (Krajowy Osrodek Baclan i Dokumentacji Zabytkow w Warszawie) in order to locate tree-lined alleys for which the year of planting was recorded. The search was limited to the region of Mazowsze (Mazovia), thus that all the locations had uniform climatic conditions. The species single outed for initial tests was belonging to all lime, a long-lived tree, many times used to line alleys and roads in central Poland.

The field measurements were made in Warsaw and in pick outed locations in the Mazowsze (Mazovia) region. They included dbh and circumference at 13 m (43 ft) height, and spacing between tree of representative age clusters made respectively with a calliper, altimeter, and measuring tape. The mean spacing between tree at all the sites was 622 m (207 ft) ?± 169 SD Tree had no visible symptoms of internal wood-land decay (e.g., cavities) and no more than 20% diadem dieback. The final inventory included 195 tree used to put together the database (Table 1). sum of two units groups of trees were used to verify the model: 17 tree 34 years aged and 15 trees 85 years of advanced age Their exact ages were obtained as in case of the protoplast group (Table 2).