sdu faculty of forestry journal special edition 2009 - Orman Fakültesi

SDÜ Faculty of Forestry Journal
Following up their health status.
Identifying main problems and the most affected species.
Evaluating if there would be an association between naturalness of trees
species and their health condition.
Proposing a ranking of the less suitable species, taking into consideration
their health features.
2. THE STUDY SITE
The study was undertaken in six districts of Madrid. This city is the capital and the
most populated city of Spain (about 3.2 million inhabitants). It is located at a latitude of
40°26′ N and a longitude of 3°41′ W with an altitude of 667m.a.s.l. The climate is
temperate Mediterranean with a marked continentality. The monthly mean minimum
temperature is 2.6º C in January and maximum, 31.2º C in July. August is the driest
month with only 10mm of precipitation, being 436mm the annual value.
Madrid has more than 1,500 public green spaces which occupy more than 9% of
its area. Besides, there are more than 300,000 street trees, without taking into
account those of green spaces.
3. METHODOLOGY
The city is administratively divided into 21 districts, and the studied green
spaces are distributed throughout six of them: Arganzuela, Barajas, Hortaleza,
Retiro, Salamanca and Villa de Vallecas.
A randomized representative sample of 25% of the green spaces in each district
was taken. Samples were collected for each year along the period 2005-2008,
although in 2007 only the green spaces of Arganzuela were examined.
Consequently, as a result of the random process, only a few green spaces were
evaluated all the years. An interesting temporary evolution was expected, so, only
the green spaces which were common to all the years in the period were analyzed
in this survey.
Sampling is a more and more used technique because of the expensiveness of
complete inventories, and it may be an accurate method for revealing the general
patterns and trends in street tree populations (Jaenson et al., 1992). Complete
inventories, such as the one which was carried out with 81,000 trees in Brussels
(Impens and Delcarte, 1979), are much more precise, but, they would not be
necessary if the management and conservation of green spaces was the target, since
“all data collected must be related to the goals of the inventory” (Smiley and
Baker, 1988).
To sum up, 49 green spaces were examined in the whole of the six districts and
they represented about 10% of the total green spaces (Figure 1).
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