| Abstract | Arboretum Hrvatske akademije znanosti i umjetnosti u Trstenom sa svojim povijesnim
perivojima spada u jedno od najvrjednijih djela krajobrazne arhitekture na području
Republike Hrvatske. Zbirka kultiviranih vrsta Arboretuma najvećim dijelom posađena u
povijesnim perivojima, uz arhitektonske i vrtnograđevinske sadržaje čini izuzetno
vrijednu komponentu, koju je potrebno revitalizirati, a biljke, osobito renesansnog
razdoblja, spasiti od daljnjeg propadanja. Afiniteti pojedinih biljnih vrsta za hranivima
značajno se razlikuju, a za njihovo usvajanje presudnu ulogu ima reakcija tla. Cilj ovog
istraživanja je bio utvrditi i istražiti biljne vrste koje su se sadile u renesansi i čine izraziti
oblikovni element u dubrovačkom renesansnom vrtu. Odabrano je pet biljnih vrsta:
vinova loza (Vitis vinifera L.), gorka naranča (Citrus aurantium L.), maslina (Olea
europaea L.), šimšir (Buxus sempervirens L.) i lovor (Laurus nobilis L.). Temeljem
vizualnih opažanja dodijeljene su ocjene zdravstvenog stanja prema intenzitetu
klorotičnosti (ocjene 0-5, tj. 0-100% klorotičnosti). Za potrebe istraživanja za svaku biljnu
vrstu tijekom 2010. i 2011. godine tlo je uzorkovano jednom na 2 dubine (0-30 i 30-60
cm), a lišće u tri navrata kako bi se odredili pH i stanje ishranjenosti. Statistička analiza
odnosila se na procjenu povezanosti između intenziteta kloroze i reakcije tla (pHH2O) s
biogenim elementima pomoću Pearsonovog korelacijskog koeficijenta (n=9) za svaku
istraživanu biljnu vrstu. Kanonička diskriminantna analiza provedena je za svaku
istraživanu biljnu vrstu u cilju procjene multivarijatne udaljenosti između ocjena kloroza
dodijeljenih vizualnim opažanjem na terenu i rezultata kemijskih analiza biogenih
elemenata (N, P, K, Mg i Ca). Temeljem provedenih istraživanja koristeći bogatu
literaturnu građu za sve odabrane biljne vrste utvrđeno je da su sađene u periodu
renesanse u perivoju u Trstenom. Vinova loza kao penjačica na odrini, gorka naranča
kao tradicijski element, maslina zbog gospodarske važnosti, a šimšir i lovor kao izraziti
oblikovni element. Rezultati kemijskih analiza ukazali su da stanje ishranjenosti vinove
loze, gorke naranče i masline nije optimalno te da su uočeni brojni debalansi koji se
manifestiraju raznim klorozama što je potvrdilo prethodna vizualna opažanja biljaka u
Arboretumu Trsteno, a osobito na vinovoj lozi i gorkoj naranči što potvrđuje i intenzitet
klorotičnosti od 60-100 %. Kod šimšira i lovora su vrijednosti većine elemenata unutar
optimalnih vrijednosti, što je također u skladu s prethodnim vizualnim opažanjima. Kod
svih pet odabranih biljnih vrsta potvrđeno je da je reakcija tla jedan od najkritičnijih
čimbenika pri odabiru biljaka u planiranju i očuvanju identiteta krajobraza. Na osnovu
dobivenih rezultata predložene su mjere revitalizacije prema metodama obnove
povijesnih vrtova koje za vinovu lozu uključuju metode konzervacije i restauracije, za
gorku naranču metode konzervacije, restauracije i rekonstrukcije, za maslinu metode
konzervacije i restauracije, za šimšir metode konzervacije, restauracije i djelomično
rekonstrukcije, te za lovor metodu konzervacije. Predloženi dizajn gnojidbe temeljem
reakcije tla, statusa ishranjenosti i zahtjeva biljaka za hranivima za svaku istraživanu
biljnu vrstu uključuje primjenu kiselih organskih i mineralnih gnojiva putem tla te folijarnu
aplikaciju koktelom makro i mikroelemenata u nekoliko navrata tijekom vegetacije. Ovo
istraživanje je dokazalo da je multidisciplinarni znanstveni pristup dizajniranju optimalne
gnojidbe u povijesnim perivojima izuzetno bitan te da je reakcija tla važan parametar pri
revitalizaciji i njezi takvih i sličnih prostora kao i pri odabiru bilja u projektiranju i očuvanju
identiteta krajobraza. Pored navedenog, dodatni doprinos ove disertacije je i utvrđeni
popis biljaka iz vremena renesanse s arhaičnim, hrvatskim i latinskim nazivima. |
| Abstract (english) | The Arboretum of the Croatian Academy of Sciences and Arts with its historic gardens
is considered to be one of the most valuable works of landscape architecture in Croatia.
The Arboretum was established on the former land estate of the Dubrovnik patrician
Gučetić-Gozze in 1948 and has been maintained for more than 500 years. The first
written record dates back to 1494 which also reveals the year of its foundation where a
contract was drawn up in which Ivan Marinov Gučetić ordered from the Korčula's stone
carvers Bartul and Fran Karlić various carved parts for his summer villa in Trsteno. From
the very founding of the estate at the end of the 15th century to today, depending on the
purpose and wishes of the owners, hundreds of plant species have been planted. The
introduction of many plants over the years reveals the image of the constantly evolving
historical gardens of the Arboretum. The plant collections of the Trsteno gardens have
evolved through historical stages and therefore in the present time chart the entire
evolutionary course. From the modest, renaissance choices, including a few baroque
novelties, to the introduction of the richness and diversity of new species from all
continents during the 19th and 20th centuries, the garden began to look like a genuine
arboretum. The collection of cultivated plants, most of which can be found in the historic
gardens accompanying architectural and garden components, is of particular
significance. It should therefore be immediately revitalized, with special focus being paid
to the plants from the Renaissance period, which needs to be protected from further
decay.
Particular plants have different requirements for nutrients and especially soil reaction
plays an important role for its uptake. Inadequate selection of soil and/or plants,
regarding the soil pH (soil reaction), eventualy results in poor appearance and decay of
plants. The reason for this is the lack of some biogenic elements that become
unavailable to plants at certain soil reactions, which causes various physiological
disorders that manifest themselves in visual symptoms: deformation of leaves,
deformation and colour changes of flowers, various chlorosis and plant necrosis,
eventual decay of the whole plants.
The aim of this research is to determine the plant species whose origin dates back to
the Renaissance period and which make an expressive design element in the Dubrovnik
Renaissance garden. Five plant species were identified and selected: grape vine (Vitis
vinifera L.), bitter orange (Citrus aurantium L.), olive tree (Olea europaea L.), boxwood
(Buxus sempervirens L.) and bay tree (Laurus nobilis L.).
The grape vine has been selected because of its indispensable qualities as a climber in
the Dubrovnik Renaissance garden. The bitter orange was selected because it has
traditionally been grown in Dubrovnik, the olives because of its economic importance in
the history of this garden. Boxwood and bay tree were selected as important forming
element of garden: boxwood because it is very important plant in development of the
garden, especially in the baroque period, and the bay tree because it exists in the garden
from its inception.
After the selection of the plant species, data collection was undertaken in the field, which
included various elements: a record of visual observations in the Arboretum, an
assessment of the health status of the plant species according to the intensity of
physiological damage – chlorosis (grades 0-5 or 0-100 % of chlorosis) and the field
measurements of soil reaction using soil reaction model (pHH2O) (class A-very acidic to
E-very alkaline).
The grape vine has been graded according to visual evaluation with 3, 4 and 5, bitter
orange with 4, 5 and 5, olive tree 2, 3 and 4, boxwood 2, 2 and 3, bay tree with 2, 3 and
3. All the soil under the selected plants showed a neutral to slightly alkaline reaction.
Based on the field research, micro-locations were selected for the purpose of this
research, where average samples of soil and plant material were taken. Soil was
sampled in autumn 2010 at two depths (0-30 and 30-60 cm) in the width of the crown of
three plants of all 5 plant species to determine soil reaction and soil nutrients status. For
each plant species, a series of plant material sampling was undertaken from plants
showing acute or latent chlorosis symptoms. The sampling has been carried out on three
occasions (autumn 2010, spring 2011 and autumn 2011).
Statistical analysis was used to estimate the correlation between intensity of chlorosis
and soil reaction (pHH2O) with biogenic elements by Pearson’s correlation coefficient
(n=9) for each researched plant species. A canonical discriminant analysis was also
carried out for each researched plant species in order to estimate the multivariate
distance between the chlorosis grades assigned by the visual field observation based
on the results of the chemical analysis of the biogenic elements (N, P, K, Mg and Ca).
The results of studying the rich literary material showed that all 5 selected plant species
were planted in the Renaissance period in the Trsteno garden.
The results of chemical analyses have shown that the nutrition status of grape vine,
bitter orange and olive tree is not optimal. The numerous imbalances, which cause
various physiological disorders, were noted. In the case of boxwood and bay tree the
values of most elements are within optimal values, and the good health status of
boxwood and bay tree also confirms low grades according to the intensity of
physiological damage – chlorosis on the field.
In grape vine there is an imbalance between the ions on alkaline soil or the lack of
potassium, and the excess of calcium and magnesium. The correlation between soil
reaction, biogenic elements and chlorosis also indicated the problem of nutrient
imbalance overall. The correlation between pHH2O and chlorosis was also noted in the
strong positive correlation (r=0,78, p<0,0136) and that chlorosis is increased by
increasing the amount of phosphorus (r=0,81, p<0,0086), while phosphorus increases
by increasing the amount of dry matter in the leaves of grape vine (r=0,78, p<0,0135).
There is also a negative correlation between K and Ca and K and Mg and a positive
correlation between Ca and Mg. The canonical discriminant analysis found a significant
difference between grades 3 and 4, 4 and 5 and 3 and 5, and phosphorus had the
greatest impact on this difference.
In the case of bitter orange, the comparing of the correlation between biogenic elements,
pHH2O and chlorosis showed that the pHH2O is in positive correlation with the intensity of
chlorosis (r=0,96, p<0,0001) and that the higher dry matter content increases the Ca in
the leaves and the higher Ca content decreases N. The antagonistic relationship was
confirmed by the negative strong correlation of K and Mg (r=-0,90, p<0,0011). An
insufficient level of zinc and manganese was also confirmed. This could be related to
the pHH2O of the analysed soil which is 8.11. The canonical discriminant analysis
revealed a significant difference between grades 4 and 5 according to the results of the
chemical analysis of leaf.
In the case of the olive tree, negative medium strong correlations between dry matter
and potassium (r=-0,70, p<0,0341) and between potassium and the intensity of chlorosis
(r=-0,71, p<0,0338) were identified. As the optimal amount of potassium and calcium
was determined and the lack of magnesium, it is possible that intensive chlorosis
appears due to the antagonism of those ions. No significant difference was found in the
canonical discriminant analysis between the grades 2, 3 and 4.
In the case of boxwood there was determined a medium strong correlation between dry
matter and magnesium (r=0,80, p<0,0099) and a negative medium strong correlation
between dry matter and zinc (r=-0,75, p<0,0188), which could lead to poorer enzymatic
activity in the plant and less resistance to stress, especially at high and low
temperatures. The canonical discriminant analysis showed no statistically significant
difference between grades according to visual evaluation (2 and 3) compared to the
results of the chemical analysis of the biogenic elements N, P, K, Mg and Ca.
In the case of the bay tree a strong negative correlation was found between dry matter
and nitrogen (r=-0,92, p<0,0004), dry matter and phosphorus (r=-0,83, p<0,0055), dry
matter and potassium (r=-0,84, p<0,0045), dry matter and copper (r=-0,95, p<0,0001),
and a medium strong negative correlation between dry matter and zinc (r=-0,78,
p<0,0129), suggesting possible imbalance of nutrients in the future. The canonical
discriminant analysis showed that there is no statistically significant difference between
grades according to visual evaluation (2 and 3) compared to the results of the chemical
analysis of the biogenic elements N, P, K, Mg and Ca.
The lack of phosphorus in the analysed plant material of boxwood and bay tree is directly
related to the lack of available phosphorus in the analysed soil as a consequence of
rinsing due to the mechanical composition of the soil under these two plant species (3238%
of sand).
In all five selected plant species, it was confirmed that soil reaction is one of the most
critical factors in selecting plants in planning and preserving the identity of the
landscape.
Based on the results, certain measures of revitalization according to the methods of the
restoration of the historical gardens have been proposed. These include the
conservation and restoration methods for grape vine, conservation, restoration and
reconstruction of the bitter orange, conservation and restoration for the olive tree,
conservation, restoration and partial reconstruction for the boxwood and bay tree
conservation method.
The proposed fertilization design based on nutrients status and plant nutrients
requirements for each researched plant species involves the application of acidic
organic and mineral fertilizers into soil and foliar application with a mixture of macro and
micro elements on several occasions during vegetation.
The outcomes of this research have demonstrated that a multidisciplinary scientific
approach in the area of optimizing fertilization in historic gardens is vital and that the soil
reaction is considered to be an important research parameter, which could then be
utilized in the revitalization and maintenance of other historical gardens. This is also
relevant in choosing plants in designing and preserving the identity of the landscape.
The results also indicate that in general, and especially for historically valuable gardens,
it is important to monitor the condition and plant needs in terms of their constant care
and fertilization to develop and maintain designed landscape as a whole.
In addition to this, an additional contribution to this dissertation is the established list of
plants from the Renaissance period with archaic, Croatian and Latin names. |
