iForest - Biogeosciences and Forestry


Decline in commercial pine nut and kernel yield in Mediterranean stone pine (Pinus pinea L.) in Spain

Rafael Calama (1-2)   , Javier Gordo (3), Sven Mutke (1-2), Mar Conde (1), Guillermo Madrigal (1-2), Enrique Garriga (4), María José Arias (5), Míriam Piqué (6), Rodrigo Gandía (7), Gregorio Montero (1-2), Marta Pardos (1-2)

iForest - Biogeosciences and Forestry, Volume 13, Issue 4, Pages 251-260 (2020)
doi: https://doi.org/10.3832/ifor3180-013
Published: Jul 03, 2020 - Copyright © 2020 SISEF

Research Articles

Cones of the Mediterranean stone pine (Pinus pinea L.) constitute one of the most relevant non-wood forest products collected in the Mediterranean forests, providing high value edible kernels. In the last years it has been observed a severe decline in the kernel-per-cone yield (kg of kernels obtained from a kg of fresh cones) through the whole area of the species. This decline has been associated with both ongoing climate change and the recent expansion over the Mediterranean Basin of the Western Conifer Seed Bug, Leptoglossus occidentalis Heideman, an exotic pest which predates seeds of conifer species. In the present work we aimed to confirm and quantify the impact of this recent decline on pine nut and kernel production, identify the main factors provoking this reduction, and give evidence over causality by a potential biotic agent. We analysed recent and historical series of pine nut and kernel production obtained in the four main regions where Pinus pinea occurs in Spain. Our results showed a significant drop in the final kernel-per-cone yield on three of the four regions analysed, reaching reductions over 50% in the most affected areas. We observed that this reduction is mainly associated with a significant and generalised drop in the kernel-per-nut yield (kg of kernels per kg of pine nuts in shell), triggered by an increment in the rate of damaged pine nuts and, to a lesser extent, a reduction in the number of pine nuts per cone. The prevalence of this reduction on kernel-per-cone yield over different years and provenances with contrasting climate reinforces the hypothesis of the implication of a biotic factor which can be aggravated on extreme drought years.


Leptoglossus occidentalis, Kernel-per-cone Yield, Cones, Exotic Pest, Seed Predation

Authors’ address

Rafael Calama 0000-0002-2598-9594
Sven Mutke 0000-0002-6365-7128
Mar Conde
Guillermo Madrigal
Gregorio Montero
Marta Pardos 0000-0002-5567-5406
INIA - Forest Research Centre, Dept. of Forest Management and Dynamics, Ctra A Coruña km 7.5, 28040 Madrid (Spain)
Javier Gordo
INIA - Forest Research Centre, Dept. of Forest Products, Ctra A Coruña km 7.5, 28040 Madrid (Spain)
Enrique Garriga
Dept. of Forest Products, INIA-CIFOR, Ctra A Coruña km 7.5, 28040 Madrid (Spain)
María José Arias
Agencia de Medio Ambiente y Agua de Andalucía, c/ Johan G. Gutenberg, 41092 Sevilla (Spain)
Míriam Piqué 0000-0002-8935-2832
Joint Research Unit CTFC- AGROTECNIO, 25280 Solsona (Spain)
Rodrigo Gandía
Servicio Territorial de Medio Ambiente de Ávila, Pasaje del Císter 1, 05071 Ávila (Spain)

Corresponding author

Rafael Calama


Calama R, Gordo J, Mutke S, Conde M, Madrigal G, Garriga E, Arias MJ, Piqué M, Gandía R, Montero G, Pardos M (2020). Decline in commercial pine nut and kernel yield in Mediterranean stone pine (Pinus pinea L.) in Spain. iForest 13: 251-260. - doi: 10.3832/ifor3180-013

Academic Editor

Massimo Faccoli

Paper history

Received: Jun 28, 2019
Accepted: Apr 29, 2020

First online: Jul 03, 2020
Publication Date: Aug 31, 2020
Publication Time: 2.17 months

Breakdown by View Type

(Waiting for server response...)

Article Usage

Total Article Views: 34006
(from publication date up to now)

Breakdown by View Type
HTML Page Views: 28850
Abstract Page Views: 2606
PDF Downloads: 1978
Citation/Reference Downloads: 10
XML Downloads: 562

Web Metrics
Days since publication: 1473
Overall contacts: 34006
Avg. contacts per week: 161.60

Article Citations

Article citations are based on data periodically collected from the Clarivate Web of Science web site
(last update: Feb 2023)

Total number of cites (since 2020): 15
Average cites per year: 3.75


Publication Metrics

by Dimensions ©

Articles citing this article

List of the papers citing this article based on CrossRef Cited-by.

Agri-Ciencia (2014)
Cadeia de valor da fileira da pinha/pinhao [Chain value for the pine nut/pine cone sector]. UNAC, Lisboa, Portugal, pp. 119. [in Portuguese]
Barta M (2016)
Biology and temperature requirements of the invasive seed bug Leptoglossus occidentalis (Heteroptera: Coreidae) in Europe. Journal of Pest Science 89: 31-44.
CrossRef | Gscholar
Bates SL, Borden JH (2005)
Life table for Leptoglossus occidentalis Heidemann (Heteroptera: Coreidae) and prediction of damage in lodgepole pine seed orchards. Agricultural and Forest Entomology 7: 145-151.
CrossRef | Gscholar
Bates SL, Strong WB, Borden JH (2002)
Abortion and seed set in lodgepole and western white pine conelets following feeding by Leptoglossus occidentalis (Heteroptera: Coreidae). Environmental Entomology 31: 1023-1029.
CrossRef | Gscholar
Bracalini M, Benedettelli S, Croci F, Terreni P, Tiberi R, Panzavolta T (2013)
Cone and seed pests of Pinus pinea: assessment and characterization of damage. Journal of Economic Entomology 106: 229-234.
CrossRef | Gscholar
Calama R, Mutke S, Sánchez-González M, Garriga E, Montero G (2007)
Modelling spatial and temporal variability on Stone pine (Pinus pinea L.) cone quality: preliminary results. In: “EFIMED Scientific Seminar: Modelling, Valuing and Managing Mediterranean Forest Ecosystem for Non-Timber Goods and Services”. Palencia (Spain) 10 Oct 2007, Oral Presentation, pp. 22.
Online | Gscholar
Calama R, Pardos M, Conde M, Madrigal G, Mutke S, Montero G, Gordo FJ (2015)
Pérdidas de rendimiento en piñón en piñas de Pinus pinea L.: análisis interregional [Decline in kernel and pine nut yields in Pinus pinea L. cones: an interregional analysis]. III Reunión Científica de Sanidad Forestal SECF. Madrid (Spain) 7-8 Oct 2015. [in Spanish]
Online | Gscholar
Calama R, Gordo J, Madrigal G, Mutke S, Conde M, Montero G, Pardos M (2016a)
Enhanced tools for predicting annual stone pine (Pinus pinea L.) cone production at tree and forest scale in Inner Spain. Forest Systems 25: e079.
CrossRef | Gscholar
Calama R, Gordo J, Raposo R, Elvira M, Mutke S, Pascual S, Pardos M (2016b)
Pine nut damage on inmature cones of Pinus pinea L.: evidences for Leptoglossus causality. In: Proceedings of the “2nd International Meeting on Mediterranean Stone Pine for Agroforestry - Agropine 2016”. Oeiras (Portugal) 18-20 May 2016. INIAV, Oeiras, Portugal, pp. 38-39.
Calama R, Fortin M, Pardos M, Manso R (2017a)
Modelling spatiotemporal dynamics of Pinus pinea cone infestation by Dioryctria mendacella. Forest Ecology and Management 389: 136-148.
CrossRef | Gscholar
Calama R, Gordo FJ, Mutke S, Madrigal G, Conde M, Raposo R, Elvira M, Pardos M (2017b)
Variabilidad espacio-temporal en el daño asociado a Leptoglossus occidentalis en pinares de Pinus pinea de la provincia de Valladolid [Spatiotemporal variability in the damage by Leptoglossus occidentailis in Pinus pinea forests in the province of Valladolid]. In: Proceedings of the “7° Congreso Forestal Español”. Plasencia (Spain) 26-30 Jun 2017. Sociedad Española de Ciencias Fisiológicas - SECF, Spain, pp. 482. [in Spanish]
Elvira-Recuenco M, Sanchez-Moreno J, Calama R, Pardos M, Mutke S, Gordo J, Pascual S, Raposo R (2016)
Damage assessment in pine nuts from stone pine caused by Leptoglossus occidentalis and pathogenic agents. In: Proceedings of the Meeting “Wild Forest Products in Europe”. Barcelona (Spain) 13-14 Oct 2016, Poster.
Online | Gscholar
Evaristo I, Batista D, Correia I, Correia P, Costa R (2010)
Chemical profiling of Portuguese Pinus pinea L. nuts. Journal of the Science of Food and Agriculture 90: 1041-1049.
CrossRef | Gscholar
Farinha AO, Branco M, Pereira MFC, Auger-Rozenberg MA, Maurício A, Yart A, Guerreiro V, Sousa ER, Roques A (2017)
Micro X-ray computed tomography suggests cooperative feeding among adult invasive bugs Leptoglossus occidentalis on mature seeds of stone pine Pinus pinea. Agriculture and Forest Entomology 20 (1): 18-27.
CrossRef | Gscholar
Farinha AO, Silva JEP, Correia AC, Sousa ER, Roques A, Branco M (2018a)
Is Leptoglossus occidentalis entirely responsible for the high damage observed on cones and seeds of Pinus pinea? Results from a fertirrigation trial in Portugal. Forest Ecology and Management 429: 198-206.
CrossRef | Gscholar
Farinha AO, Durpoix C, Valente S, Sousa E, Roques A, Branco M (2018b)
The stone pine, Pinus pinea L., a new highly rewarding host for the invasive Leptoglossus occidentalis. Neobiota 41: 1-18.
CrossRef | Gscholar
Fent M, Kment P (2011)
First record of the invasive western conifer seed bug Leptoglossus occidentalis (Heteroptera: Coreidae) in Turkey. North-Western Journal of Zoology 7: 72-80.
Online | Gscholar
Freire J, Tome M, Silva S, Ribeiro C, Teles M (2016)
Silvicultural guidelines for managing P. pinea stands in a southeastern Portuguese region for cone production. Revised silvicultural guidelines for selected MPT and NWFPs. StarTree Deliverable 2.3, FP7 Project no 311919 KBBE 2012 (1): 2-06. European Commission, Brussels, Belgium, pp. 58-70.
Gordo J, Mutke S, Prada MA (1999)
El pino piñonero (Pinus pinea L.) [The Stone pine]. In: “Mejora genética y masas productoras de semilla de los pinares españoles” (Alía R, Galera R, Martín S eds). INIA, Madrid, Spain, pp. 223-239. [in Spanish]
Guadaño C, Iglesias S, Leon D, Arribas S, Gordo J, Gil L, Montero G, Mutke S (2016)
Establecimiento de plantaciones clonales de Pinus pinea para la producción de piñón mediterráneo [Estabishing clonal plantations with Pinus pinea to promote pine nut production]. Monografías INIA 28, Madrid, Spain, pp. 80. [in Spanish]
INC (2012)
Nuts and dried fruits. Global statistical review 2007-2012. Reus, Spain, pp. 67.
Online | Gscholar
Lesieur V, Yart A, Guilbon S, Lorme P, Auger-Rozenberg MA, Roques A (2014)
The invasive Leptoglossus seed bug, a threat for commercial seed crops, but for conifer diversity? Biological Invasions 16: 1833-1849.
CrossRef | Gscholar
Lesieur V, Lombaertz E, Guillemaud T, Courtial B, Strong W, Roques A, Auger-Rozenberg MA (2018)
The rapid spread of Leptoglossus occidentalis in Europe: a bridgehead invasion. Journal of Pest Science 92: 189-200.
CrossRef | Gscholar
Loewe-Muñoz V, Balzarini M, Delard C, Alvarez A (2019)
Variability of stone pine (Pinus pinea L.) fruit traits impacting pine nut yield. Annals of Forest Science 76: 37.
CrossRef | Gscholar
Montero G, Candela JA, Rodríguez Navarro AC (2004)
El pino piñonero (Pinus pinea L.) en Andalucía: ecología, distribución y selvicultura [Stone pine (Pinus pinea L.) in Andalusia: ecology, distribution and silviculture]. Junta de Andalucía, Sevilla, Spain, pp. 261. [in Spanish]
Morales L (2009)
Modelos para la predicción del contenido y calidad de piñón en piñas de Pinus pinea L. en los Valles del Tiétar y del Alberche [Empirical model for predicting pine nut content and quality in Pinus pinea L. cones from Tietar and Alberche Valleys]. MSc thesis, ETSI Montes, Universidad Politécnica de Madrid, Madrid, Spain, pp. 149. [in Spanish]
Mutke S, Gordo J, Gil L (2005)
Variability of Mediterranean Stone pine cone production: yield loss as response to climate change. Agricultural and Forest Meteorology 132 (3-4): 263-272.
CrossRef | Gscholar
Mutke S, Iglesias S, Gil L (2007)
Selección de clones de pino piñonero sobresalientes en la producción de piña [Selection of Mediterranean stone pine clones for cone production]. Investigación Agraria, Sistemas y Recursos Forestales 16: 39-51. [in Spanish]
CrossRef | Gscholar
Mutke S, Calama R, Nasrallah Neaymeh E, Roques A (2017)
Impact of the Dry Cone Syndrome on commercial kernel yield of stone pine cones. Options Méditerranéennes A 122: 79-84.
Online | Gscholar
Parlak S, Kilci M, Sayman M, Akkas ME, Bucak C, Boza Z (2013)
Climate factors and their relation regarding cone yield of stone pine (Pinus pinea L.) in the Kozak Basin, Turkey. Options Méditerranéennes A 105: 15-19.
Online | Gscholar
Parlak S (2017)
An invasive species: Leptoglossus occidentalis (Heidemann) how does it affect forestry activities? Kastamonu University, Journal of Forestry Faculty 17 (3): 531-542.
CrossRef | Gscholar
Ozçankaya M, Balay SN, Bucak C (2013)
Effects of pests and diseases on stone pine (Pinus pinea L.) conelet losses in Kozak catchment area. Options Méditerranéennes A 105: 29-33.
Online | Gscholar
Pasalodos-Tato M, Pukkala T, Calama R, Cañellas I, Sánchez-González M (2016)
Optimal management of Pinus pinea stands when cone and timber production are considered. European Journal of Forest Research 135: 607-619.
CrossRef | Gscholar
Piqué M, Calama R, Mutke S, Nemer NM, Abou Daher MA, Abou-Fakhr E, Bassil M, Freiha A, Neaymeh EN, Hayek ML, Hamid AH, Sathyapala S (2017)
Guidelines for integrated management of sustainable pine forests. Paper no. TCP/LEB/3501, FAO/Ministry of Agriculture, Beirut, Lebanon, pp. 48. [in Arabic]
Ponce L, Ponce A, Sacristan A, Pajares JA (2017)
Daños estacionales a piñas y piñones de Pinus pinea de diferentes edades causados por Leptoglossus occidentalis Heidemann (Heteroptera, Coreidae) [Stational damage in P. pinea cones and pine nuts provoked by Leptoglossus occidentalis Heidemann (Heteroptera, Coreidae)]. In: Proceedings of the “7° Congreso Forestal Español”. Plasencia (Spain) 26-30 Jun 2017. Sociedad Española de Ciencias Fisiológicas - SECF, Spain, pp. 463. [in Spanish]
Prada MA, Gordo FJ, De Miguel J, Mutke S, Catalán G, Iglesias S, Gil L (1997)
Regiones de procedencia de Pinus pinea [Provenance regions for Pinus pinea]. Ministerio de Medio Ambiente, Madrid, Spain, pp. 109. [in Spanish]
Salas-Salvadó J, Casas-Agustench P, Salas-Huetos A (2011)
Cultural and historical aspects of Mediterranean nuts with emphasis on their attributed healthy and nutritional properties. Nutrition, Metabolism and Cardiovascular Diseases 21: 1-6.
CrossRef | Gscholar
Sousa E, Ferreira C, Pimpão M, Naves P, Valdiviesso T, Varela C (2012)
Sanidade dos povoamentos de pinheiro manso em Portugal [Health state of Pinus pinea forests in Portugal]. In: Proceedings of the Meeting “Valorização da Fileira da Pinha/Pinhão” (Calado N ed). Alcácer do Sal (Portugal) Sept 2012. Oral presentation, pp. 36. [in Portuguese]
Online | Gscholar
Strong WB, Bates SL, Stoehr MU (2001)
Feeding by Leptoglossus occidentalis (Hemiptera: Coreidae) reduces seed set in lodgpole pine (Pinaceae). The Canadian Entomologist 133: 857-865.
CrossRef | Gscholar
Tiberi R (2007)
Danni alla fruttificazione del Pino Domestico: indagine sulle cause e sulle perdite di produzione [Damage to Stone pine fruiting: findings on main cause and losses ofproduction]. Technical Report, Arsia - University of Firenze - Regione Toscana, Florence, Italy, pp. 19. [in Italian]
Villaseñor D (2018)
Aplicación de las TIG para la determinación de la influencia del paisaje en Leptoglossus occidentalis (Hemiptera: Coreidae) en pinares de la provincia de Valladolid [Applying GIS to determine the effect of landscape structure on Leptoglossus occidentalis (Hemiptera: Coreidae) behaviour in pinewood of Valladolid province]. MSc Thesis, Faculty of Geography, Universidad Complutense de Madrid, Madrid, Spain, pp. 61. [in Spanish]

This website uses cookies to ensure you get the best experience on our website. More info