Spatiotemporal variation in acorn production and damage in a Spanish holm oak (Quercus ilex) dehesa

L. Perez Izquierdo, F. Pulido


Aim of study. There is a lack of knowledge about spatio-temporal patterns of acorn production in dehesas, especially regarding the influence of different agents causing acorn damage. We examined the spatial and temporal variability on acorn production and damage in four stands within a dehesa farm in 1997, 1998 and 1999.

Area of study. The study was carried out in a 1800 ha dehesa farm of Cáceres province, western Spain.

Material and Methods. Acorns were sampled by means of seed traps placed in the canopy of six holm oak trees per stand. Acorn collected in it were counted and assessed for damage by Curculio weevils, Cydia moths and the bacterial pathogen Brenneria quercina.

Main results. Mean acorn production for the whole study period was 44.60 acorns m-2, which did not vary significantly either among stands or among years. The variability among individual trees was very high (0-300 acorns m-2). The rate of infestation by Curculio was 7.64 ± 10.72 %, by Cydia was 1.76 ± 3.33 %, whereas 10.29 ± 16.12 % of acorns were infested by Brenneria. We found no significant spatial differences, but the rates of acorn loss by insects varied among years. These rates were independent of annual acorn production and there was no correlation among damages by different pests, except between Curculio and Cydia in two crop years.

Research highlights. It can be concluded that acorn crops are synchronized at the within-farm level and that the temporal variation in acorn damages can be independent of crop size.

Keywords: Acorn production; Brenneria; Curculio; Cydia; dehesa; Quercus ilex; spatio-temporal variation.

Full Text:



Abrahamson WG, Layne JN, 2003. Long-term patterns of acorn production for five oak species in xeric Floridauplands. Ecology 84: 2476-2492.

Alejano R, Vázquez-Piqué J, Carevic F, Fernández M, 2011.Do ecological and silvicultural factors influence acornmass in Holm Oak (southwestern Spain)? Agroforest Syst83: 25-39.

Alejano R, Domingo JM, Fernández M, 2012. Manual para la gestión sostenible de las dehesas andaluzas. Foro Encinal-Universidad de Huelva, Spain.

Álvarez S, Morales R, Bejarano L, Durán A, 2002. Producción de bellota en la dehesa Salmantina. In: Chocarro C et al. (eds). XLII Reunión Científica de la SEEP, Lérida. pp: 645-650.

Bonal R, Muñoz A, 2007. Multitrophic effects of ungulate intraguild predation on acorn weevils. Oecologia 152: 533-540. PMid:17351797

Bonal R, Muñoz A, Díaz M, 2007. Satiation of predispersal seed predators: the importance of considering both plant and seed levels. Evol Ecol 21: 367-380.

Cañellas I, Roig S, Poblaciones MJ, Gea-Izquierdo G, Olea L, 2007. An approach to acorn production in Iberian dehesas. Agroforest Syst 70: 3-9.

Carevic FS, Fernández M, Alejano R, Vázquez-Piqué J, Tapias R, Corral E, Domingo J, 2010. Plant water relations and edaphoclimatic conditions affecting acorn production in a holm oak (Quercus ilex L. ssp. ballota) open woodland. Agroforest Syst 7: 299-308.

Crawley MJ, Long CR, 1995. Alternate bearing, predator satiation and seedling recruitment in Quercus robur L. J Ecol 83: 683-696.

Debouzie D, Desouhant E, Oberli F, Menu F, 2002. Resource limitation in natural populations of phytophagous insects. A long-term study case with the chestnut weevil. Acta Oecol 23: 31-39.

Díaz M, Pulido J, 1995. Relaciones entre la abundancia de artrópodos y las carácterísticas vegetativas de la encina (Quercus ilex). Utilidad de su modelización empírica en la gestión forestal de las dehesas. Bol San Vegetal, Plagas 21: 3-8.

Díaz M, Pulido F, Moller AP, 2004. Herbivore effects on developmental instability and fecundity of holm oaks. Oecologia 139: 224-234. PMid:14968355

Díaz M, Alonso CL, Arroyo L, Bonal R, Muñoz A, Smit C, 2009. Desarrollo de un protocolo de seguimiento a largo plazo de los organismos clave para el funcionamiento de los bosques mediterráneos. MARM, Madrid, Spain.

Espelta JM, Cortés P, Molowny-Horas R, Sánchez-Humanes B, Retana J, 2008. Masting mediated by summer drought reduces acorn predation in mediterranean oak forests. Ecology 89: 805-817. PMid:18459343

Espelta JM, Cortés SP, Molowny-Horas R, Retana J, 2009. Acorn crop size and pre-dispersal predation determine inter-specif ic differences in the recruitment of co-occurring oaks. Oecologia 161: 559-568. PMid:19544074

Fearer T, Norman G, Pack J, Bittner S, Healy W, 2008. Influence of physiographic and climatic factors on spatial patterns of acorn production in Maryland and Virginia, USA. J Biogeogr 35: 2012-2025.

Fukumoto H, Kajimura H, 2011. Effects of asynchronous acorn production by co-occurring Quercus trees on resource utilization by acorn-feeding insects. J For Res 16: 62-67.

García-Mozo H, Gómez-Casero MT, Domínguez E, Galán C, 2007. Influence of pollen emission and weather-related factors on variations in holm-oak (Quercus ilex subsp. ballota) acorn production. Env Exp Bot 61: 35-40.

Gea-Izquierdo G, Cañellas I, Montero G, 2006. Acorn production in Spanish holm oak woodlands. Invest Agrar: Sist Recur For 15: 339-354.

Gómez JM, Luis E, Escudero A, 1980. Materiales aportados al suelo por la encina en la zona de dehesas salmantina. I. Sustancia seca. Stud Oecol II: 181-211.

Healy WM, Lewis AM, Boose EF, 1999. Variation of red oak acorn production. Forest Ecol Manag 116: 1-11.

Jiménez A, López MA, González-Andújar JL, Ocete ME, Soria FJ, 2008. Distribución espacial y mapeo de Curculioelephas Gyllenhal en encina (Quercus ilex L.). Agrociencia 12: 35-43.

Jones CG, Lawton JH, Shachak M, 1994. Organisms as ecosystem engineers. Oikos 69: 373-386.

Kelly D, 1994. The evolutionary ecology of mast seeding. Trend Ecol Evol 9: 465-470.

Kelly D, Sork V, 2002. Mast seeding in perennial plants: why, how, where? Ann Rev Ecol Syst 33: 427-447.

Koenig W, Knops J, Carmen W, Stanback M, 1999. Spatial dynamics in the absence of dispersal: acorn production by oaks in central coastal California. Ecography 22: 499-506.

Koenig WD, Knops JMH, 2000. Patterns of annual seed production by Northern Hemisphere trees: a global perspective. Am Nat 155: 59-69. PMid:10657177

Leiva MJ, Fernández-Alés R, 2005. Holm-oak (Quercus ilex subsp. Ballota) acorns infestation by insects in Mediterranean dehesas and shrublandsIts effect on acorn germination and seedling emergence. Forest Ecol Manag 212: 221-229.

Liebhold A, Sork V, Peltonen M, Koenig W, Bjornstad ON, Westfall R, Elkinton J, Knops JMH, 2004. Within-population spatial synchrony in mast seeding of North American oaks. Oikos 104: 156-164.

Manel S, Debouzie D, 1997. Modeling insect development time of two or more larval stages in the field under variable temperatures. Env Entomol 26: 163-169.

Martín-Vicente A, Infante JM, García-Gordo J, Merino J, Fernández-Alés R, 1998. Producción de bellotas en montes y dehesas del suroeste espa-ol. Pastos 28: 237-248.

Montero G, Martín D, Cañellas I, Campos P, 2002. Selvicultura y producción del alcornocal. In: La gestión forestal de las dehesas (Pulido FJ, Campos P, Montero G, eds). IPROCOR, Mérida, Spain. pp: 63-102. PMid:12241076

Moreno G, Pulido FJ, 2009. The functioning, management and persistence of dehesas. In: Agroforestry in Europe: current status and future prospects (Rigueiro-Rodríguez, McAdam J, Mosquera-Losada MR, eds). Adv in Agrofor 6: 127-160.

Nieto R, Ribera M, García MA, Aguilera JF, 2002. Amino acid availability and energy value of acorn in the Iberian pig. Livest Prod Sci 77: 227-239.

Pérez-Laorga E, Giménez A, Ibáñez A, González-Arbolafio R, González-Biosca E, López-González MM, 2005. Ensayo de control de Curculioelephas en bellotas de encina (Quercus ilex). IV Congreso Forestal Nacional, Zaragoza, Spain. Septiembre.

Pérez-Ramos IM, Ourcival JM, Limousin JM, Rambal S, 2010. Mast seeding under increasing drought: results from a long-term data set and from a rainfall exclusion experiment. Ecology 91: 3057-3068. PMid:21058565

Peter D, Harrington C, 2009. Synchronicity and geographic variation in Oregon white oak acorn production in the Pacific Northwest synchronicity and geographic variation in Oregon white oak acorn.Weather 83: 117-130.

Pulido FJ, 1999. Herbivorismo y regeneración de la encina (Quercus ilex L.) en bosques y dehesas. Tesis doctoral. Universidad de Extremadura, Spain. PMCid:2168101

Pulido FJ, Díaz M, 2005. Regeneration of a Mediterranean oak: a whole-cycle approach. Ecoscience 12: 92-102.

Pulido FJ, García E, Obrador JJ, Moreno G, 2010. Multiple pathways for tree regeneration in anthropogenic savannas: incorporating biotic and abiotic drivers into management schemes. J Appl Ecol 47: 1272-1281.

Rivest D, Rolo V, López-Díaz L, Moreno G, 2011. Shrub encroachment in Mediterranean silvopastoral systems: Retamas phaerocarpa and Cistus ladanifer induce contrasting effects on pasture and Quercus ilex production. Agric Ecosyst Environ 141: 447- 454.

San Miguel A, 1994. La dehesa española. Origen, tipología, características y gestión. Fundación Conde del Valle de Salazar, Madrid, Spain. PMCid:502027

Soria S, López MM, López-López MM, 1997. Presencia, sintomatología y daños de Erwinia Quercina en España y su posible relación con la "seca de la encina". Ecología 11: 295-301.

Soria FJ, Vellagrán M, Martín P, Ocete ME, 1999. Curculioelephas (Gyllenhal) (Coleoptera: Curculionidae) y Cydia fagiglandana (Zeller) (Lepidoptera: Tortricidae) en encina (Quercus rotundifolia Lam.): infestación y relaciones interespecíficas. Bol San Veg Plagas: 25, 125-130.

Sork V.L, Bramble J, Sexton O, 1993. Ecology of mastfruiting in three species of North American deciduous oaks. Ecology 74: 528-541.

Soula B, Menu F, 2003. Variability in diapauses duration in the chestnut weevil: mixed ESS, genetic polymorphism orbet-hedging? Oikos 100: 574- 580.

Torres E, Alejano R, Alaejos J, 2004. Hacia una modelización de la producción de bellota en encinares (Quercus ilex ballota). In: Reunión del grupo de trabajo sobre modelización forestal de la SECF (García-Criado B et al., eds). ETSI Agrónomos y Montes, Palencia, Spain.

Vázquez FM, Balbuena E, Doncel E, Ramos S, 1999. Distribución del "melazo" en dehesas de Quercus rotundifolia Lam. para la cosecha de bellotas de 1999 en la provincia de Badajoz. Bol San Veg Plagas 26: 287-296.

Yu Z, Zhou H, Luo T, 2003. Spatial and temporal variations in insect-infested acorn fall in a Quercus liaotungensis forests in North China. Ecol Res 18: 155-164.

DOI: 10.5424/fs/2013221-03328