Evaluación del impacto por descortezamiento ocasionado por la ardilla del vientre rojo, Callosciurus erythraeus, sobre sistemas arbóreos en el partido de Luján y alrededores
The introduction of exotic species that become invasive is one of the main environmental problems due to the lost on native biodiversity, as well as to the negative impacts on socio-productive activities, on health and even on cultural aspects. The red-bellied squirrel Callosciurus erythraeus was in...
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| Formato: | Tesis info:ar-repo/semantics/doctoralThesis info:ar-repo/semantics/tesis de doctorado acceptedVersion |
| Lenguaje: | Español Español |
| Publicado: |
Universidad Nacional de Luján
2021
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| Materias: | |
| Acceso en línea: | http://ri.unlu.edu.ar/xmlui/handle/rediunlu/873 |
| Aporte de: |
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I62-R168-rediunlu-873 |
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dspace |
| institution |
Universidad Nacional de Luján (UNLu) |
| institution_str |
I-62 |
| repository_str |
R-168 |
| collection |
REDIUNLu - Repositorio Digital Institucional de Acceso Abierto - Universidad Nacional de Luján (UNLu) |
| language |
Español Español |
| topic |
Ardilla de vientre rojo Descortezado Invasiones biológicas Impacto productivo Red-bellied squirrel Bark stripping Biological invasions Productive impact |
| spellingShingle |
Ardilla de vientre rojo Descortezado Invasiones biológicas Impacto productivo Red-bellied squirrel Bark stripping Biological invasions Productive impact Pedreira, Paula Anabel Evaluación del impacto por descortezamiento ocasionado por la ardilla del vientre rojo, Callosciurus erythraeus, sobre sistemas arbóreos en el partido de Luján y alrededores |
| topic_facet |
Ardilla de vientre rojo Descortezado Invasiones biológicas Impacto productivo Red-bellied squirrel Bark stripping Biological invasions Productive impact |
| format |
Thesis info:ar-repo/semantics/doctoralThesis info:ar-repo/semantics/tesis de doctorado acceptedVersion |
| author |
Pedreira, Paula Anabel |
| author_facet |
Pedreira, Paula Anabel |
| author_sort |
Pedreira, Paula Anabel |
| title |
Evaluación del impacto por descortezamiento ocasionado por la ardilla del vientre rojo, Callosciurus erythraeus, sobre sistemas arbóreos en el partido de Luján y alrededores |
| title_short |
Evaluación del impacto por descortezamiento ocasionado por la ardilla del vientre rojo, Callosciurus erythraeus, sobre sistemas arbóreos en el partido de Luján y alrededores |
| title_full |
Evaluación del impacto por descortezamiento ocasionado por la ardilla del vientre rojo, Callosciurus erythraeus, sobre sistemas arbóreos en el partido de Luján y alrededores |
| title_fullStr |
Evaluación del impacto por descortezamiento ocasionado por la ardilla del vientre rojo, Callosciurus erythraeus, sobre sistemas arbóreos en el partido de Luján y alrededores |
| title_full_unstemmed |
Evaluación del impacto por descortezamiento ocasionado por la ardilla del vientre rojo, Callosciurus erythraeus, sobre sistemas arbóreos en el partido de Luján y alrededores |
| title_sort |
evaluación del impacto por descortezamiento ocasionado por la ardilla del vientre rojo, callosciurus erythraeus, sobre sistemas arbóreos en el partido de luján y alrededores |
| publisher |
Universidad Nacional de Luján |
| publishDate |
2021 |
| url |
http://ri.unlu.edu.ar/xmlui/handle/rediunlu/873 |
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AT pedreirapaulaanabel evaluaciondelimpactopordescortezamientoocasionadoporlaardilladelvientrerojocallosciuruserythraeussobresistemasarboreosenelpartidodelujanyalrededores |
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Repositorios |
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1764820546342617088 |
| description |
The introduction of exotic species that become invasive is one of the main environmental problems due to the lost on native biodiversity, as well as to the negative impacts on socio-productive activities, on health and even on cultural aspects. The red-bellied squirrel Callosciurus erythraeus was introduced into our country 50 years ago and is considered a very successful and a continuously growing invader. Its expansion is accelerated by people who carry out intentional captures, deliberate transportations and intentional releases, generating new foci of invasion. It is present in four Argentine provinces (Buenos Aires, Córdoba, Santa Fe and Mendoza), with the greatest affected area present in the Province of Buenos Aires, where it is considered a harmful species according to the rural code. Like other squirrels, this species removes the bark from trees for different reasons (v.g. nesting, obtaining sap, territorial marking, agonistic encounters) and the economic damage to the forest industry is mentioned in the literature. In Argentina, although there are records of debarking by C. erythraeus in different tree species, there are no detailed studies that describe and quantify this kind of damage. The general aim of this Thesis was to characterize the debarking caused by the red-bellied squirrel and evaluate its impact on tree systems within the Luján district (Buenos Aires), within the original focus of the invasion, where the squirrel population is already established. We worked in four wooded areas (two in the City of Luján, one in the city of Jáuregui and one in the City of Open Door), surveying a total of 542 trees. The tree species with squirrel damage and the selection of tree items used for debarking were recorded (and Ivlev index was calculated); the characteristics of the external wounds (in terms of their dimensions and age), and the affected internal tissues were also analyzed. The characteristics of the debarked trees in terms of its dasometric variables (DBH and height), the prevalence of damage (debarked trees / total trees evaluated) globally and seasonally, and the implications of some environmental variables on the mentioned incidence, were studied. In Liebres Fue site (Jáuregui), which has plantations of three commercial species (pine Pinus elliottii, eucaliptus Eucalyptus dunnii and poplar Populus deltoides), we studied the effect of the debarking on yield (wood volume, growth defects), the economic losses and the quality of wood surveying trees of two different ages, assessing a total of 412 trees.
The overall debarking damage (recent and oldest damage) showed that C. erytrhaeus behaves as a generalist species, affecting a wide spectrum of species (n=25) (84% of available species in the study site). Squirrels damaged tree species in a different way in relation to their availability: Ivlev index showed a weak positive selection for perennial gymnosperms trunks and deciduous angiosperm branches, using tree species differentially depending on the seasons. Damaged trees had higher DBH
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than non-damaged trees, but there were no differences in height although squirrels caused damage in a wide range of tree heights (from 1 to 25 m). Two general forms of external wounds (cross and longitudinal) were confirmed in both branches and trunks, and three variants of the longitudinal wounds were observed in trunks (typical longitudinal, patches and scratch); the intensity of damage (% trunk or tree canopy damage) did not have a specific arboreal pattern, but showed a tendency to be higher in deciduous angiosperms and evergreens gymnosperms. The average ringing (% of the total circumference of the damaged trunk or branch) was also important, being in some species higher than 40%. The environmental factors that could be associated with the higher prevalence of bark stripping were: the abundance of squirrels, the arboreal diversity of the sites and the arboreal abundance. When considering only the recent debarking, it was observed that the incidence of damage was close to 10%, being higher in spring. At the same time, it was observed that bark stripping caused by squirrels influenced the internal anatomy of wood, affecting the growth tissues in all the samples tested, both, in branches and trunks.
Taking into account the commercial species evaluated, we found that there was an effect of squirrel damage on wood yield, finding greater growth defects in eucalyptus and poplar, like breaks. This leads to lower average values of wood volume, which translates into economic losses that vary between 400 and 3,800 dollars / ha. Finally, the different responses of the trees to the damages, affected the quality of the wood in all the tables evaluated. This fact prevented assigning the best quality categories (Premium or Select) to the pieces in all the cases, due to the internal defects (simple cracks, cracks with abnormal coloring, cracks with resin or cinchona, and cracks with bark, in terms of presence and magnitude). This disqualifies the wood pieces for a potential sawing. This is the first systematic study that aims to evaluate the impact of bark stripping caused by red-bellied squirrels on tree systems in our country. The knowledge generated in this Thesis is an input for future studies assessing the impact of bark stripping in other forest systems, such as cultivated, natural or native forest, and is a valuable contribution to the analysis of this mammal species as a potential phytosanitary pest. This will generate more support when proposing and outlining possible management actions for red bellied squirrel, including prevent and/or control actions of the species and damage mitigation. |