Evaluating acorn crops in an oak-dominated stand to identify good acorn producers

Titre

Evaluating acorn crops in an oak-dominated stand to identify good acorn producers

Austrian Journal of Forest Science

Créateur

Mehdi Pourhashemi

Daniel C. Dey

Dariush Mehdifar

Parisa Panahi

Mehdi Zandebasiri

Sujet

Acorn density

Acorn production

Brant's oak

Crop size

Crown count

Zagros forests

Date

2018

uri

https://www.researchgate.net/publication/328661522_Evaluating_acorn_crops_in_an_oak-dominated_stand_to_identify_good_acorn_producers

Résumé

Acorn production in the Zagros forests of Iran is important for its fundamental role in the natural sexual regeneration of oaks, for human use, and as food for wildlife. The objectives of this study were to examine annual variability in acorn production among individuals of Brant`s oak (Quercus brantii Lindl.), the effect of tree quantitative variables as well as weather variables on acorn production and determine whether any pattern in fruiting can be used to identify the good acorn producers. Starting in 2012, 100 individual Brant`s oaks were selected and their acorn crops were measured by the tree count method during six years (2012-2017). Acorn production performance of each tree and annual acorn crops were ranked as "good", "fair" or "poor". The mean number of acorns per m2 crown area (CA) among years and diameter classes and the correlations between 13 weather variables with acorn production was analysed too. During the study period, average annual acorn production per tree ranged from 0 to 2293 acorns. The mean density of acorns per m2 CA varied from a low of 1.2 in 2015 to a high of 13.4 in 2016. Acorn crop failures did not occur during our period. Based on the mean 6-year acorn crop, good, fair and poor producers comprised 35%, 19%, and 46% of the sample trees, respectively. The mean 6-year acorn crop did not vary significantly among diameter classes. Furthermore, two weather variables, spring maximum temperature 1 yr prior to the year of acorn maturation and summer rain during the year of acorn maturation, had positive significant effect on annual acorn production. Our results confirmed that there is great annual variation in acorn production among individuals of Brant`s oak. Because actual good acorn producers represent a small proportion of seed bearing oaks (16%), they should be identified for appropriate management and conservation

volume

35

numéro

3

pages

213-234

Langue

en