Eucalyptus Globulus: Characteristics, Habitat, Importance And Uses

Eucalyptus globulus Labill. is a tree native to southeastern Australia commonly known as eucalyptus, white eucalyptus, blue gum or fever tree. Its name derives from the Greek eu (good or good) and kalipto (cover).

Regarding its growth, it is a species that reaches between 30 to 50 meters in height, including heights of 80, 90 and 100 meters have been recorded. On the other hand, there are reports of trees that measure up to 10 meters, which are considered small.

Curiously, this tree has both favorable and unfavorable characteristics; since it is widely used in medicine, in the logging industry, as well as as a biological controller for mosquitoes that transmit malaria, in swamps; but also, it is an aggressive tree for ecosystems due to the drying it produces. 

Being a species considered fast growing, it is used mainly in the production of paper pulp. Regarding its distribution, due to its great utility, it has been introduced in various countries in Europe, South America, Africa and Asia.

characteristics

Trunk

It is a tree with a cylindrical trunk, erect and thick, up to 2 meters. Its wood is rich in water, light yellowish brown in color, which when broken produces long leaves joined together. Its texture is open, with interlocking grain and well-evident growth rings.

In addition, it is characterized by being strong and relatively durable, since it contains around 47% cellulose and 27% lignin. Its fibers have a length ranging from 0.81 to 1.06 mm, with a diameter of 19.6 microns.

Cup

It has an elongated and irregular crown, on a shaft of branches.

Cortex

It has a bark of approximately 3 cm thick, brown in color, which peels off in long strips when ripe, revealing a second smooth bark, indicating that it is a type of deciduous bark. On certain occasions it expels resin.

Leaves

Its juvenile leaves are oval, of the opposite type, sessile, amplexicaul and glaucous, approximately 8 – 15 cm long and 4 – 8 cm wide. These have a bluish color when they are young and are arranged on quadrangular stems.

In turn, the adult leaves are alternate, petiolate, linearly lanceolate, 15 – 25 cm long, with a greyish-green pointed apex.

Due to these differences present in the leaves, when passing from the juvenile state to the adult state, this species presents sexual dimorphism.

flowers

Its flowers are white or creamy, these are found in the axils of the leaves, solitary or in groups of 2 – 3, measuring up to 3 cm in diameter. Its petals, when expanding, form a kind of layer. It has male and female organs, which flourish when the adult foliage appears.  

The flowers of this plant have a very important characteristic, since they are producers of abundant honey, generally white in color, being considered melliferous, which favors the transport of pollen and pollination.

Likewise, this species tends to differ from other species by the characteristic aroma of its flowers, which its flowers produce.

Inflorescence

It has a cymeus inflorescence, which indicates that they open from the inside out; presenting a defined growth, in which the central axis ends in a flower and downwards the others appear successively; dicasial type, since two branches arise below the terminal flower, normally contracted.

Fruit

It is shaped like a bell-shaped capsule, with a woody texture and glaucous color, covered with a whitish powder, with a length of approximately 1.4 to 3 cm in diameter.

Seed

They are numerous and tiny, black in color and rough in texture. These are released through the valves of the fruit, which open at ripening. Its production begins at 5 years. About 70 viable seeds can be found per gram.

Taxonomy

Eucalyptus, white eucalyptus, blue gum or fever tree; are the most common names used to refer to the speciesEucalyptus globulus Labill.

Its taxonomic description is as follows:

– Kingdom: Plantae

– Phylum: Tracheophyta

– Class: Magnoliopsida

– Order: Myrtales

– Family: Myrtaceae

– Gender: Eucalyptus

– Species: Eucalyptus globulus Labill.

Habitat and distribution

In relation to its habitat, the eucalyptus develops optimally in areas with humid and cool environments. Excessive cold with frosts, areas with prolonged dry periods and frequent winds above 8 m / s influence its development. 

However, there are reports that indicate that it can withstand high temperatures, given its ability to absorb water.

Now, in terms of its distribution, this tree is a native of Tasmania, an island in southern Australia. However, it is found in many countries in Europe, Africa, Asia and South America.

It is noteworthy that its spatial distribution closely follows all those areas with ecological aptitude for its development. 

Edaphoclimatic characteristics

For the optimal development of the species Eucalyptus globulus Labill., It is important to take into account the following requirements:

Weather

– Precipitation: approximately 800 to 1500 mm.

– Temperature: from 10.8 ° C to 16.8 ° C.

– Humidity: requires medium humidity.

– Wind: winds, if possible not higher than 8m / s.

Floors

As for its edaphic requirement, it demands sandy loam – clayey, or sandy – clayey soils, with good drainage and little compaction. A pH of 5 to 7 is necessary.

In addition to these characteristics, it is vitally important to take into account the following factors that limit the good development of this plant:

– Low levels of boron and phosphorus in soils.

– The altitude. It is necessary to bear in mind an altitude, between 2200 and 3300 meters above sea level

– The fog. The more presence of mist, the more affected will be the development of the plant.

– Low light. The absence of light has an unfavorable influence.

– Risk of fire. As it has a dry bark, it is very susceptible to fire. However, it does not cause any serious damage, since they are quite resistant. Therefore, they are called pyrophytic trees.

– In terms of water consumption, it has a great water absorption capacity. However, it is not a limiting factor for their growth, and they do not have the resource available for excessive consumption.

Plagues and diseases

Pests

Eucalyptus is generally attacked by insects such as: Ericoccus coriaceus, Paropsis obsoleta, Euproctis chrysorrhoea (moth), Ctenarytaina eucalypti, Phicnopeltella eucalypti, Altica ampelophaga (aphid), Gonipterus scutellatus (eucalyptus weevil), Phoracantha semipunctata (eucalyptus borer beetle), ants of the genera Atta and Acromyrmex.

Diseases

Among the most common are those that affect its roots. They are usually transmitted by bacteria, fungi and pathogens.

It should be noted that the “blue sickness” disease is determined by the bluish-green spots that appear on the stem and the dry leaves near this area. This disease attacks both young plants and adult plants.

It is also important to mention the brown rot disease of the core, caused by Polyporus sulphureus; and diseases that affect the seed, caused byPenicillum sp. andFusarium sp.

Now, among the fungi that cause diseases such as damping, there are those belonging to the genera Fusarium, Phytophtora and Phytium, and gray mold caused by Botrytis cinerea. In addition, fungi of the genera Armillaria, Alternaria, Diplodia and Corticium and Stereum.

Importance and Uses

This tree is used in various areas, being highly valued from a medicinal and economic point of view. 

Wood industry 

The species Eucalyptus globulus Labill. It has one of the best woods for the manufacture of pulp and paper. It is considered the perfect fiber tree for printing and writing papers. 

Fundamentally, its qualities are due to the fact that the wood of this species is composed of fibers of short and homogeneous length, thus characterized by great softness, excellent rigidity, great dimensional stability and strong resistance to humidity.

Consequently, being a fast-growing, high-yielding species, it reduces the consumption of chemicals in the cooking and bleaching processes.

Likewise, it is used as a structural element in constructions (columns, beams, parquet, and other types of floors). Likewise, sawn wood is used, since it is used in the manufacture of furniture, coatings and other elements in carpentry.

It is even intended for firewood, producing quality biofuels, as it has a high calorific value and burns well, leaving little ash. Likewise, it is used for the production of coal, since it is easily charred.

Medicinal properties 

In addition to wood, its leaves are also used. Curiously, the leaves of this species, compared to the other eucalyptus, are the most used as medicinal.

The eucalyptus leaves are rich in tannins and essential oils, which allows the preparation of therapeutic infusions, special for conditions of the respiratory system because it produces a bronchodilator effect.

Other uses 

It should be noted that these oils extracted from the leaves are marketed under the designation cineole or eucalyptol. They are used in lotions, as flavorings and in the pharmaceutical industry for local and internal use.

Additionally, this oil is used as an insect repellent thanks to its camphor aroma. 

References

  1. Azzazy M. 2016. Environmental impacts of industrial pollution on pollen morphology of Eucalyptus globulus Labill. (Myrtaceae). J. App. Biology Biotech, 4 (05), 057-062.
  2. Catalog of Life: 2019 Annual Checklist. 2019.Eucalyptus globulus Labill. Taken from: catalogueoflife.org
  3. Di Marco E. 2015. Eucalytus globulus sp. Globulus Labill. (White eucalyptus) Family Myrtaceae. Data sheet. Directorate of forest production. Buenos Aires, Argentina. pp 36.
  4. Gonzalez R., Silva G., Urbina A. and Gerding M. 2016. Essential oil of Eucalyptus globulus Labill. and Eucalyptus nitens H. Dance & Maiden (Myrtaceae) for the control of Sitophilus Zea mays Motschulsky. Chilean J. Agric. Anim. Sci., Former Agro-Science. 2016. 32 (3): 204-216.
  5. James S. and Bell D. 2001. Leaf morphological and anatomical characteristics of heteroblastic Eucalyptus globulus ssp. globulus (Myrtaceae). Australian Journal of Botany, 49 (2), 259-269.
  6. Pereira J., Sturion J., Higa A., Higa R., and Shimizu J. 2000. Characteristics of wood from some eucalyptus species planted in Brazil. Embrapa Florestas-Documents (INFOTECA-E).

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