Situation of Chestnut Owners in Canary Islands

CURRENT SITUATION OF THE CHESTNEST OWNER IN THE CANARY ISLANDS Due to their ability to produce allelopathic substances (humus has a high tannin content; Broun et al., 1993), European deciduous trees, like the chestnut tree, have been presented as clear competitors of the Monteverde species in areas where the laurel forest may recover (Pérez-Chacón et al., 1984). These trees have a tendency to form monospecific forests. As of right now, research indicates that they do not do as much harm, supporting the presence of species characteristic of the shrubby and herbaceous layer of the future lauri silva forest. Some of the tree species have even been shown to cohabit with them (Suárez, 1999). Braun et al. (1993) investigated the natural regeneration of heather (Erica arborea) and laurel (Laurus azorica) in the chestnut forest area of this space on the Osorio farm. They verified that the removal of livestock that grazed in the forest until the 1980s of the 20th century, as well as the forestry cultivation work (pruning of chestnut trees and extraction of foreign species), had a significant positive impact on the settlement of Monteverde species. In regions of particular significance, chestnut trees were planted in response to the demand for wood or poles and, of course, for fruit harvesting. The Cabildo of Gran Canaria completed significant forestry projects in the middle of the 20th century, including planting chestnut trees. The information supplied by Jaime O'Shanahan serves as a guide, showing how certain jobs are costly and complicated. It has been essential to dig holes in the Cruz de Tejeda that are at least one cubic meter long in order to exploit a hole at the bottom that fractures the subsoil and makes it easier for roots to subsequently penetrate. After planting, they must be watered by the first summer, but in order to do so, the water must be transported by tanker trucks as far as they can go, and from there, it must be carried to the most difficult locations by persons who are used to climbing peaks (O'Shanahan, 1953). According to Naranjo Borges (2001), the chestnut trees that are still standing are stunted, ancient, or have exhausted vines. In certain ravine bottoms, robust chestnut trees reach heights of more than 25 meters. The Canary Islands Forest Plan, which recommends planting the tree as a forest fruit tree or creating mixed stands with Monteverde species, will determine the fate of the chestnut forests in the islands. Gran Canaria's laurel forest will benefit from the removal of the chestnut tree. The Heredad de Aguas de Arucas and Firgas, in Valsendero, which were planted in the early 1940s (Águedo Marrero Rodriguez, personal communication), the Osorio Estate, which was planted in the mid-18th century, and San Isidro, in Teror, which was located on Doctoral Juan González Falcón's farm, are some of the most significant forests in the archipelago. The logging that took place during the Great European War would severely damage the latter (Vicente Hernández Jiménez, personal communication). The island is 442 hectares in total, of which half are monospecific chestnut forests and the other half are mixed woods with 47% chestnut trees and monteverde components, particularly heather and laurel (personal email from Jorge Naranjo Borges). In Tenerife, the La Orotava Valley has thick formations, while in Acentejo and Santa Úrsula, chestnut trees coexist with heather. The biggest additions on La Palma may be found at Mazo and Las Breñas. Regarding the size of the chestnut grove in the province of Santa Cruz de Tenerife, no trustworthy information could be located.