Tree - Height Growth
Significant height growth is experienced by a wide range of tree species when grown within a treeshelter. Here we indicate the level of growth improvement experienced for a range of species and discuss factors that might affect variations.
To date, millions of trees have been established in Tubex treeshelters around the globe. This establishment in the early and delicate phase in the growth of a tree is accelerated thanks to the specific microclimate created within the treeshelter. The design of an ideal treeshelter takes into account all the microclimatic parameters to offer the plant the nutrients and the external factors it needs to grow healthily.
The tables below are based on experiments run in the early eighties by the Forestry Commission in England. The tree species are categorised in 3 classes based on the mean height increment of various tree species 3 years after planting in shelters compared with trees in mesh guards. It is noteworthy that, if compared with trees grown without protection, the growth would be even more significant.
These tables provide a guideline as various publications around the world have shown that the incremental growth can vary depending on local climate, soil, precipitation, plant quality, etc. For more detailed and specific information on the performance of treeshelters on other tree species, please contact Tubex Sales Team.
Trees grouped in Class A exhibit high mean height increment of more than 100% in shelters compared to trees grown in mesh guards. It is due to this spectacular growth that these trees are often used in treeshelter research.
Tree species in Class B grow well in treeshelters. The mean height increment is between 50% and 100% greater than that of trees in mesh guards.
Tree species in Class C grow well in treeshelters although more slowly. The mean height increment is around 50% greater than that of trees in mesh guards with recorded heights of 50 to 100 centimetres (20 to 40 inches). Although the growth enhancement is not as significant for these trees, treeshelters do provide the other important benefits.
Sometimes the evidence of tree growth provides different results. In such cases, it is important to identify the specific growth and living conditions of the trees and the type of the treeshelters. Recent research studies on treeshelters have shown that factors such as light transmission in the visible radiations range (photosynthesis), in the infra-red range (heat), and in the red and far-red narrow bands (photomorphogenesis), ventilation with constant carbon dioxide feed (Ventex), etc., have important contributory effects on the amount of growth.
The best example illustrating the importance of living conditions of trees is shown by the beech (Fagus sylvatica). Beech responds very well to treeshelters with height increment of around 4 times greater than control trees after 2 growing seasons and around 2 times after 5 years. High survival rates reaching 100 % has also been recorded. However, other reports claim less pronounced growth of beech. A thorough investigation led by the Forestry Commission showed that the combined presence of the beech woolly aphid (Phyllaphis fagi), inadequate weed control and poor quality plants all contributed to more variable results. In shelters, beech exhibits a prolonged phase of growth and produces thinly-cuticularised leaves, an ideal site for the woolly aphid. It is therefore of paramount importance that the beech seedlings are treated with the appropriate insecticides before planting. This is normally carried out in the nurseries.
Numerous studies on the effect of treeshelters on a variety of trees have been run by academic research and forest institutions around the world and have confirmed Mr Graham Tuley’s (Forestry Commission – UK) findings. As an example, the microclimate effect of a treeshelter on the growth of oak trees is clearly shown in this Canadian study. The second year height increment of oak (Quercus Robur) grown in treeshelters, treeguards and in natural environment are shown.
As an example, the figure shows the first season growth, in conditions of irrigation, of a wild cherry tree (Prunus avium L.) inside an unventilated (plain tube) and a ventilated treeshelter (Ventex design) in comparison with a tree grown without a shelter (control).
The main factors that affect the height growth in a treeshelter are: light transmission and ventilation. Both factors have a direct impact on the 4 processes of photosynthesis, photomorphogenesis, respiration and transpiration. Indeed, the design of the wall structure of the treeshelter provides the right type and intensity of light and air circulation. The latter provides feed in CO2 to the growing tree and regulates the moisture in the air surrounding the plant. These factors are optimised in the design of the Equilibre Ventex treeshelter.
Potter, M. J., Treeshelters, Forestry Commission Handbook 7, 1991, pp 21-25. London: HMSO.
Kerr Gary & Evans H., Beech in treeshelters, Quaterly Journal of Forestry, 1993, 87, 107-115.
Dupraz C., Sparrer P. Influence d'abris-serres sur la croissance de merisiers et de noyers cultivés en conteneurs. Doc. Int., 1988, Inra-Lecsa, 29p.
Dupraz Christian, Bergez J.E. Effect of ventilation on growth of Prunus avium seedlings grown in treeshelters. Agricultural and Forest Meteorology 104 (2000) 199–214.
Dupraz C, Coutand Catherine, Jaouen Gaelle, Ploquin Stephane, and Adam Boris.
Mechanical Stimuli Regulate the Allocation of Biomass in Trees: Demonstration with Young Prunus avium Trees. Annals of Botany, in press.
F. Famiani, P. Proietti, M. Micheli, M. Boco, A. Standardi, F. Ferranti, L. Reale. Effects of tree shelters on young olive (Olea europaea) tree growth and physiology. New Zealand Journal of Crop and Horticultural Science, 2007, Vol. 35: 303–312.