An Evaluation of Treeshelter Effects on Plant Survival and Growth in a Mediterranean Climate

Abstract

A four-year study was conducted to evaluate the effects of treeshelters on the growth and survival of three oak species and Douglas fir growing in a Mediterranean climate. Trees were planted in irrigated and nonirrigated plots, enclosed in treeshelters or tree guards, and measured annually for height and diameter growth. In nonirrigated plots, both treeshelters and tree guards improved oak survival, but generally did not produce significant height or diameter growth increases over unprotected controls. In irrigated plots, plant growth and survival was substantially greater than that in nonirrigated plots. Irrigated trees with protection (shelters or guards) showed substantially greater survival levels than unprotected trees. Height growth was greatest in treeshelters and diameter growth was roughly equivalent for all irrigated treatments. Irrigated trees continued to grow when irrigation was discontinued after three years, and treeshelter trees exhibited little or no lean when shelters were removed. Trees without irrigation in Mediterranean climates should not be expected to exhibit growth enhancement effects from treeshelters equivalent to those found in temperate climates.

Impacts of mulching and tree shelters on cork oak (Quercus suber L.) seedling survival and growth after four growing seasons

“…In addition, the effects of tree shelters and mulching have frequently been examined in separate experiments, but rarely in concert. Furthermore, classically measured parameters in studying the effect of treatments on oak growth (i.e., height, basal diameter, and biomass growth (Costello et al, 1996;McCreary & Tecklin, 1997)) do not account for the typically rhythmic pattern of height growth in oak species (Reich et al, 1980;Champagnat et al, 1986;Harmer 1990;Mechergui et al, 2012). The study of this growth pattern involves the division of the main stem into growth units, and provides useful information on this growth response characterization.…”

Weed control and use of tree shelters: improving restoration success of degraded north Patagonian forests

“…Several studies suggest that seedling growth and survival can be significantly increased with the protection given by tree shelters (Costello et al 1996;Dubois et al 2000;Weitkamp et al 2001;Jacobs and Steinbeck 2001;Sweeney et al 2002;Ponder 2003;Dorji et al 2020). These responses have been attributed to an improvement of microclimatic conditions within the shelter environment (Potter 1988;Zastrowd and Marty 1991;Kjelgren et al 1994;Peterson et al 1994;Dupraz 1997, 2000;Oliet and Jacobs 2007;Jacobs 2011).…”