The Parks and Gardens Bureau, under the Department of Public Services of the Santa Cruz City Council, will proceed to fell and replace 46 trees located in the Ramón y Cajal Prolongation, given the poor condition in which they are found. To do this, it will invest 88,000 euros in the operation of felling and replanting species more suitable for the area.
This is reflected in the report prepared by the new concessionaire of the Parks and Gardens maintenance contract, at the request of the area directed by Carlos Tarife.
In the case of the specimens of the extension of Ramón y Cajal, according to the report prepared by the joint venture FCC-Acciona, for several years complaints have been received from the public for the inconvenience caused by the trees on this street, which are Jacaranda mimosifolia. The complaints mainly allude to cleaning problems on sidewalks, vehicles, furniture and buildings, generated by the molasses produced by the cochineal that affects them.
The report details that “the trees on this street have a disproportionate crown between their dimensions and their vegetation that reveals their weakness.” They add that, “at the phytosanitary level, they are usually affected by the Orthezia insignis mealybug, being a common and persistent pest in the Jacaranda genus.”
It is explained that these insects suck the sap from the leaves and excrete a sugary and sticky liquid (molasses) that ends up impregnating both the leaves of the trees and the environment covered by the treetops (sidewalks, pavements, facades, vehicles, furniture). urban, etc.) with the consequent inconvenience for citizens and generating the need for greater cleaning of sidewalks. On the other hand, a fungus known as “bold or sooty mold” settles on said molasses, which gives it the blackish appearance that tree trunks present.
It is pointed out that, for years, phytosanitary treatments have been applied against this cochineal, although “it must be taken into account that the regulations related to phytosanitary products are increasingly restrictive and restricted, therefore, in compliance and adaptation of said regulations, the treatments applied are not effective enough to visibly reduce the pest and with it, the undesirable side effects it produces”. Added to all this are the limited vegetative conditions that the trees have in the tree wells (scarce and depleted soil, rise in average temperatures, low rainfall…), plus all the factors that suffer from urban circumstances (pollution, excessive dog urination… ).
In the study, each of the trees that make up the alignments of the Ramón y Cajal Prolongation have been analyzed, and it concludes that, of the 51 existing jacaranda specimens, at least 46 present significant alterations (88%). At the phytosanitary level, all the trees are severely affected by the Orthezia insignis mealybug, while all the specimens have a very unprotected crown, with a low leaf percentage, due to the action of the pest.
This condition may be related to the low vitality of the specimens, probably associated with a poor and compacted soil, a situation that could not be mitigated despite the different phytosanitary treatments or nutritional contributions made in the past.
recommendations
The recommendation of the report is that, given that the dimensions of both sidewalks allow it, all the trees should be replaced (except for a large specimen of Delonix regia), after improving the existing tree pits, as well as providing an automated sprinkler system across the street. It is also suggested that the replacement of the new trees be carried out using specimens of other species that are more resistant to being affected by mealybugs, also taking into account the dimensions of the space in which they are going to be located.
For the right side, having a fairly wide sidewalk and lacking buildings, it is proposed to plant specimens that can reach a large size (for example Tipuana tipu). For the left sidewalk, due to the presence of buildings with several floors, as well as premises or terraces, smaller specimens are recommended, using two or three different species (Tabebuia sp., Radermachera sinica or Metrosideros excelsa).
Based on these conclusions, the area requested the preparation of a budget, which resulted in an investment of 88,000 euros, to replace the current trees with new specimens of the Tipuana tipu species for the right side and Tabebuias for the left side. all produced in the municipal nursery. The action must include the replacement of topsoil and the installation of an irrigation network.
