PINUS AYACAHUITE: CHARACTERISTICS, HABITAT, CARE, PESTS, USES - BIOLOGY - 2025

Pinus ayacahuite is a species of arboreal plant between 25 and 40 m in height with unfolded and whorled branches belonging to the Pinaceae family. Known as ayacahuite colorado, acalocahuite, cahuite, cahuite pine, royal pine, pinabete, white ocote, gretado ocote, tuusha, wiyoko and wiyo, it is native to Mexico and Central America.

The ayacahuite is an evergreen coniferous species that grows up to 45 m in height with a straight, cylindrical trunk. The crown of the tree is pyramidal or conical in shape, with irregular and open branching in old trees.

Pinus ayacahuite. Source: Source: Silversyrpher

This pine provides a very good quality soft wood, commonly used for construction, handicrafts, joinery, sawdust, pulp and paper. Its importance lies in its attractive appearance, being ideal for commercial plantations, and can be used as an ornamental tree in parks, sports fields and open fields.

Previously it was common to observe extensive plantations of Pinus ayacahuite, producing large volumes of wood as a raw material for carpentry and cabinetmaking. These forestry operations have practically been exhausted, especially in Mexico and Mesoamerica; hence the need to implement conservation and reforestation programs for the species.

General characteristics

Morphology

The Pinus ayacahuite is a tree that can reach 35-40 m in height, with a firm and straight shaft of permanent foliage and a pyramidal crown. In young plants the bark is thin, smooth and light gray in color. When ripe, the bark is thick, rough and dark gray in color.

The thin, elongated needle leaves (10-18 cm long) are terminally located in groups of 4-6 needles. These bright green needles with the lightest veins have slightly jagged margins that are barely perceptible to the touch.

Needles. Source: Petr Filippov

The large female cones (15-40 cm), cylindrical in shape and woody in appearance, are slightly curved and hanging, and have abundant arched scales. Light brown in color, when ripe they have a viscous consistency due to the high content of resins.

The smaller male cones are arranged terminally on the twigs. The tiny, oval, light brown seeds with dark spots have a papery wing 10-20 mm long.

Taxonomy

- Kingdom: Plantae

- Division: Spermatophyta

- Subdivision: Gymnospermae

- Class: Pinopsida

- Subclass: Pinidae

- Order: Pinales

- Family: Pinaceae

- Genus: Pinus

- Species: Pinus ayacahuite Ehrenb. ex Schltdl.

Subspecies

- Pinus ayacahuite var. ayacahuite Ehrenb.

- P. ayacahuite var. veitchii (Roezl) Shaw

- Pinus strobiformis Engelm

Etymology

- Pinus: corresponds to the generic Latin designation for pine.

- Ayacahuite: derived from the Nahuatl āyauhcuahuitl, where āyahuitl means fog, and cuahuitl, tree. Thus, the full term means tree of mist.

Distribution and habitat

Species native to the Mesoamerican region between 14 - 21º North latitude from southwestern Mexico along the Sierra Madre del Sur. In Mexico it is restricted to the states of Chiapas, Guerrero, Oaxaca, Pueblo and Veracruz. It is also possible to find it in Guatemala, Honduras and El Salvador.

The Pinus ayacahuite grows in deep soils, with a sandy loam texture, at altitude levels between 1,800 - 3,000 meters above sea level. In addition, it is located in humid places (such as streams and streams) with an average annual rainfall between 800 - 1,500 mm and an average temperature of 13 - 17º C.

Natural habitat of ayacahuite. Source: Alejandro Linares Garcia

Likewise, it adapts to poor soils with a low content of organic matter. It requires well-drained soils, since despite supporting drought well, it does not tolerate waterlogging.

In its natural habitat it is associated with oak forests or other pine trees such as Pinus montezumae, P. patula or P. rudis, and over 2,000 meters above sea level with P. chiapensis. It is a cold tolerant species, in temperate climates it supports temperatures below 30º C.

Care

The propagation of Pinus ayacahuite is carried out through seeds or by tissue culture (embryos) at the laboratory level. In the case of seeds, they are obtained directly from the plant, from healthy individuals free of pests and diseases and excellent phenotypic characteristics.

The sowing is carried out in polyethylene bags on a loose substrate made up of sand, plant material (peel, sawdust) and organic matter. It takes 10 to 12 months for the seedling to reach 30 - 40 cm in height, a good time to sow in the final field.

Cones Source: Silversyrpher from Scotland, UK

In the nursery, foliar or slow release fertilization and mycorrhizal inoculations are recommended to obtain healthy and vigorous plants. Weeding during the initial growth phase is essential to avoid competition for light, water and nutrients, favoring the health of the crop.

It is advisable to keep only one plant per container, performing the peal when the seedlings reach 10 - 15 cm in height. In this case the most vigorous seedling is selected and the most fragile is discarded.

One month before the final sowing, the plants must be conditioned to stimulate their growth. To do this, fertilization is suspended, sporadic waterings are carried out until they are reduced, and the plants are placed in full sun exposure.

The Ayacahuite pine grows rapidly in the nursery, sometimes reaching more than 50 cm in height, which can cause a management problem. For this reason, it is advisable to carry out apical pruning, in plants with more than one year in the nursery, in order to homogenize the size of the plantation.

Once the plantation is established, thinning and intermediate pruning are required to stimulate growth and increase the harvest of useful material. Pruning is for maintenance, training or sanitation, removing badly formed or diseased trees.

Plagues and diseases

In the nursery, the presence of insects of the genus Eucosma sp. and Conophthorus sp. that affect the seeds. Its control is carried out by means of agronomic practices or the application of contact insecticides.

During the growth phase the Pinus ayacahuite is attacked by barking insects considered a forest pest of pine forests. Among these, the Dendroctonus adjunctus, Dendroctonus frontalis and Dendroctonus mexicanus stand out, being recommended the control with systemic insecticides or the integral management.

Dendroctonus frontalis. Source: Erich G. Vallery

The larvae of the Lepidoptera Rhyacionia buoliana and Rhyacionia duplana cause wounds and galleries in the buds or young shoots in their search for food. It can also be attacked by other insects such as the larvae of the beetle Pissodes zitacuarense, whose larvae affect the vascular system.

Among the defoliators of the Diprionidae family commonly called "sawfly" are those of the genus Neodiprion spp. This pest massively affects pine forests, the damage being caused mainly by larvae when defoliating entire branches.

In the case of debarkers, borers and defoliators, chemical control and cultural management are the recommended measures. Regarding diseases, the Pinus ayacahuite is attacked by the Cronartium sp. Fungus, which causes cone rust.

Applications

The wood of the Pinus ayacahuite, soft and malleable, is used for rural constructions, carpentry, joinery, fences and as firewood for combustion. This species is used for reforestation of peri-urban areas, parks, avenues and sports fields, as well as being used as a Christmas tree.

At an industrial level, the resin extracted from wood is used for the production of pitch and turpentine. Likewise, this resin has medicinal properties for the treatment of respiratory problems, and as an antiseptic for ear infection.

References

1. Ayacahuite, Acalocahuite, Pino Tabla (2018) Green Neighbors: Common trees in cities. National Commission for the Knowledge and Use of Biodiversity. Recovered in: biodiversity.gob.mx
2. Ayacahuite, the Mexican Christmas tree (2007) Electronic magazine of the Forestry Commission, Number 74. Retrieved from: abcuniversidades.com
3. Honorato Salazar, JA, Apolinar Hidalgo, F. & Colotl Hernández, G. (2016) Lignocellulosic composition of Pinus ayacahuite Ehrenb. ex Schltdl., P. leiophylla Schlecht. & Cham. and P. herrerae Martínez. Mexican Journal of Forest Sciences, 7 (34), 47-56.
4. López López, B., Gálvez Arce, P., Calleja Peláez, B., Méndez González, J., & Ríos Camey, JM (2018). Organic substrates in the germination and growth of Pinus ayacahuite var. veitchii (Roezl) Shaw in nursery. Mexican Journal of Forest Sciences, 9 (49), 110-124.
5. Musálem, MA, & Luis, R. (2003). Monograph of Pinus ayacahuite var. veitchii Shaw. México, DF: National Institute of Forestry and Livestock Research.
6. Pinus ayacahuite (2018) Wikipedia, The free encyclopedia. Recovered at: es.wikipedia.org