View More View Less
  • 1 Universidad de Salamanca Área Departamental de Ecología, Facultad de Biología Campus Miguel de Unamuno 37071 Salamanca Spain
  • | 2 Universidad de La Serena Instituto de Ecología y Biodiversidad (IEB), Facultad de Ciencias Av. Raúl Bitrán Nacharay sn La Serena Chile
  • | 3 Universidad de Salamanca Área Departamental de Edafología, Facultad de Ciencias Ambientales 37071 Salamanca Spain
Restricted access

In arid and semi-arid ecosystems, the presence of woody neighbours affects the existence of several herbaceous species by modifying critical aspects of the environment (e.g., soil humidity, nutrient content or light availability) beneath their canopies. Herbaceous species growing in the understory of Pinus pinaster may be distinct from those in open areas due to litter fall, light interception and changes in nutrient availability. We suggest that the overall effect of woody neighbours on herbaceous layer diversity may vary with the scale focus of analysis. To examine this hypothesis, we collected data on the abundance of herbaceous species in open pineland forests of the central Iberian Peninsula (Spain) using sample quadrats of 0.5 m × 0.5 m distributed beneath, at the edge, and outside the canopy of pines in a landscape composed of dunes and plains. The results of CCA ordination revealed significant spatial segregation of herbaceous species reflecting the occurrence of pines and dunes in the landscape. Nested ANOVA disclosed markedly lower species richness beneath the pines, particularly in the dune sites. Species richness partitioning showed higher pine-induced heterogeneity than expected from the sample-based randomized model, leading to significantly increased species richness at the patch level. Hence, the outcome of pine-induced effects on the herbaceous plant diversity is scale-dependent, negative if we focus on separate communities, but positive if the scale focus is extended to whole patches comprising the sum of communities beneath, at the edge, and outside pine tree canopies. These results emphasize the necessity of using various scale perspectives to clarify the different ways in which pines and other woody nurse species affect structure of herbaceous communities in semi-arid Mediterranean ecosystems.

  • Álvarez, A.M., C. Casquet, J.M. Fuster, L. Martín-Parra, J. Martínez-Salanova, and M. Pinado. 1987. Mapa geológico de España 1:50,000 . Nava de la Asunción (hoja n‡ 456) Serv. Publ. Min. Industria y Energía, Madrid.

    Pinado M. , '', in Mapa geológico de España 1:50,000 , (1987 ) -.

  • Álvarez, A.M., V. Cala and J. González. 1993. El factor edáfico en humedales de Cantalejo (provincia de Segovia). Ecología 7: 37–45.

    González J. , 'El factor edáfico en humedales de Cantalejo (provincia de Segovia) ' (1993 ) 7 Ecología : 37 -45.

    • Search Google Scholar
  • Barbier, S., F. Gosselin and P. Balandier. 2008. Influence of tree species on understory vegetation diversity and mechanisms involved. A critical review for temperate and boreal forests. Forest Ecol. Manag. 254 (1): 1–15.

    Balandier P. , 'Influence of tree species on understory vegetation diversity and mechanisms involved. A critical review for temperate and boreal forests ' (2008 ) 2541 Forest Ecol. Manag. : 1 -15.

    • Search Google Scholar
  • Bertness, M.D. and R.M. Callaway. 1994. Positive interactions in communities. Trends Ecol. Evol. 9: 191–193.

    Callaway R.M. , 'Positive interactions in communities ' (1994 ) 9 Trends Ecol. Evol. : 191 -193.

    • Search Google Scholar
  • Bertness, M.D. and S.D. Hacker. 1994. Physical stress and positive associations among plants. Am. Nat. 144: 363–372.

    Hacker S.D. , 'Physical stress and positive associations among plants ' (1994 ) 144 Am. Nat. : 363 -372.

    • Search Google Scholar
  • Birkett, M.A., K. Chamberlain, A.M. Hooper and J.A. Pickett. 2001. Does allelopathy offer real promise for practical weed management and for explaining rhizosphere interactions involving higher plants? Plant Soil 232: 31–39.

    Pickett J.A. , 'Does allelopathy offer real promise for practical weed management and for explaining rhizosphere interactions involving higher plants? ' (2001 ) 232 Plant Soil : 31 -39.

    • Search Google Scholar
  • Brooker, R.W. and T.V. Callagham. 1998. The balance between positive and negative plant interactions and its relationship to environmental gradients: a model. Oikos 81: 196–207.

    Callagham T.V. , 'The balance between positive and negative plant interactions and its relationship to environmental gradients: a model ' (1998 ) 81 Oikos : 196 -207.

    • Search Google Scholar
  • Callaway, R.M., N.M. Nadkarni and B.E. Mahall. 1991. Facilitation and interference of Quercus douglasii on understory productivity in central California. Ecology 72: 1484–1499.

    Mahall B.E. , 'Facilitation and interference of Quercus douglasii on understory productivity in central California ' (1991 ) 72 Ecology : 1484 -1499.

    • Search Google Scholar
  • Callaway, R.M. 1995. Positive interactions among plants. Bot. Rev. 61: 306–349.

    Callaway R.M. , 'Positive interactions among plants ' (1995 ) 61 Bot. Rev. : 306 -349.

  • Callaway, R.M. and L.R. Walker. 1997. Competition and facilitation: a synthetic approach to interactions in plant communities. Ecology 78: 1958–965.

    Walker L.R. , 'Competition and facilitation: a synthetic approach to interactions in plant communities ' (1997 ) 78 Ecology : 1958 -965.

    • Search Google Scholar
  • Callaway, R.M. and F.I. Pugnaire. 1999. Facilitation in plant communities. In: Pugnaire, F.I. & F. Valladares (eds.), Handbook of Functional Plant Ecology . Marcel Dekker, New York. pp 272–313.

    Pugnaire F.I. , '', in Handbook of Functional Plant Ecology , (1999 ) -.

  • Callaway, R.M., Z. Kikvidze and D. Kikodze. 2000. Facilitation by unpalatable weeds may conserve plant diversity in overgrazed meadows in the Caucasus Mountains. Oikos 89: 275–282.

    Kikodze D. , 'Facilitation by unpalatable weeds may conserve plant diversity in overgrazed meadows in the Caucasus Mountains ' (2000 ) 89 Oikos : 275 -282.

    • Search Google Scholar
  • Callaway, R.M. 2007. Positive Interactions and Interdependence in Plant Communities . Springer, Dordrecht.

    Callaway R.M. , '', in Positive Interactions and Interdependence in Plant Communities , (2007 ) -.

  • Calonge, G. 1987. El complejo ecológico y la organización de la explotación forestal en la Tierra de Pinares Segoviana . Diputación Provincial de Segovia, Segovia.

    Calonge G. , '', in El complejo ecológico y la organización de la explotación forestal en la Tierra de Pinares Segoviana , (1987 ) -.

  • Calvo, L., S. Santalla, L. Valbuena, E. Marcos, R. Tárrega and E. Luis-Calabuig. 2008. Post-fire natural regeneration of a Pinus pinaster forest in NW Spain. Plant Ecol. 197: 81–90.

    Luis-Calabuig E. , 'Post-fire natural regeneration of a Pinus pinaster forest in NW Spain ' (2008 ) 197 Plant Ecol. : 81 -90.

    • Search Google Scholar
  • Cavieres, L.A. and E.I. Badano. 2009. Do facilitative interactions increase species richness at the entire community level? J Ecol. 97: 1181–1191.

    Badano E.I. , 'Do facilitative interactions increase species richness at the entire community level? ' (2009 ) 97 J Ecol. : 1181 -1191.

    • Search Google Scholar
  • Cornell, H.V. 1999. Unsaturation and regional influences on species richness in ecological communties: a review of evidence. Ecoscience 6: 1–13.

    Cornell H.V. , 'Unsaturation and regional influences on species richness in ecological communties: a review of evidence ' (1999 ) 6 Ecoscience : 1 -13.

    • Search Google Scholar
  • Cornell, H.V. and J.H. Lawton. 1992. Species interactions, local and regional processes, and limits to the richness of ecological communities: a theoretical perspective. J. Anim. Ecol. 61: 1–12.

    Lawton J.H. , 'Species interactions, local and regional processes, and limits to the richness of ecological communities: a theoretical perspective ' (1992 ) 61 J. Anim. Ecol. : 1 -12.

    • Search Google Scholar
  • Costa-Tenorio, M., C. Morla and H. Sáinz-Ollero. 1997. Los bosques ibéricos. Una interpretación Geobotánica . Planeta, Barcelona.

    Sáinz-Ollero H. , '', in Los bosques ibéricos. Una interpretación Geobotánica , (1997 ) -.

  • Crist, T.O., J.A. Veech, J.C. Gering and K.S. Summerville. 2003. Partitioning species diversity across landscapes and regions: a hierarchical analysis of α, β and γ diversity. Am. Nat. 162: 734–743.

    Summerville K.S. , 'Partitioning species diversity across landscapes and regions: a hierarchical analysis of α, β and γ diversity ' (2003 ) 162 Am. Nat. : 734 -743.

    • Search Google Scholar
  • Gering, J.C., T.O. Crist and J.A. Veech. 2003. Additive partitioning of species diversity across multiple spatial scales: implication for regional conservation of biodiversity. Conserv. Biol. 17: 488–499.

    Veech J.A. , 'Additive partitioning of species diversity across multiple spatial scales: implication for regional conservation of biodiversity ' (2003 ) 17 Conserv. Biol. : 488 -499.

    • Search Google Scholar
  • Gillian, F.S. and M.R. Roberts. 2003. Interactions between the herbaceous layer and overstory canopy of eastern forests: a mechanism for linkage. In: Gillian, F.S. and M.R. Roberts (eds.). The Herbaceous Layer in Forests of Eastern North America . Oxford University Press, New York. pp 198–223.

    Roberts M.R. , '', in The Herbaceous Layer in Forests of Eastern North America , (2003 ) -.

  • González-Alday, J., C. Martínez-Ruíz and F. Bravo. 2009. Evaluating different harvest intensities over understory diversity and pine seedlings, in a Pinus pinaster Aiton natural stand of Spain. Plant Ecol. 201: 211–220.

    Bravo F. , 'Evaluating different harvest intensities over understory diversity and pine seedlings, in a Pinus pinaster Aiton natural stand of Spain ' (2009 ) 201 Plant Ecol. : 211 -220.

    • Search Google Scholar
  • Greenlee, J.P. and R.M. Callaway. 1996. Effects of abiotic stress on the relative importance of interference and facilitation. Am. Nat. 148: 386–396.

    Callaway R.M. , 'Effects of abiotic stress on the relative importance of interference and facilitation ' (1996 ) 148 Am. Nat. : 386 -396.

    • Search Google Scholar
  • Gutiérrez J.R., P.L. Meserve, L.C. Contreras, H. Vásquez and F.M. Jaksic. 1993. Spatial distribution of soil nutrients and ephemeral plants underneath and outside the canopy of Porlieria chilensis shrubs (Zygophyllaceae) in arid coastal Chile. Oecologia 95: 347–352.

    Jaksic F.M. , 'Spatial distribution of soil nutrients and ephemeral plants underneath and outside the canopy of Porlieria chilensis shrubs (Zygophyllaceae) in arid coastal Chile ' (1993 ) 95 Oecologia : 347 -352.

    • Search Google Scholar
  • Hacker, S.D. and S.D. Gaines. 1997. Some implications of direct positive interactions for community species diversity. Ecology 78: 1990–2003.

    Gaines S.D. , 'Some implications of direct positive interactions for community species diversity ' (1997 ) 78 Ecology : 1990 -2003.

    • Search Google Scholar
  • Ha-Lin Zhao, Rui-Lian Zhou, Yong.Zong Su, Hua Zang, Li-Ya Zhao and S. Drake. 2007. Shrub facilitation of desert land restoration in the Horqin Sand Land of Inner Mongolia. Ecol. Eng. 31: 1–8.

    Drake S. , 'Shrub facilitation of desert land restoration in the Horqin Sand Land of Inner Mongolia ' (2007 ) 31 Ecol. Eng. : 1 -8.

    • Search Google Scholar
  • Holzapfel, C., K. Tielbörger, H.A. Parag, J. Kiegel and M. Sternberg. 2006. Annual plant-shrub interactions along an aridity gradient. Basic Appl. Ecol. 7: 268–279.

    Sternberg M. , 'Annual plant-shrub interactions along an aridity gradient ' (2006 ) 7 Basic Appl. Ecol. : 268 -279.

    • Search Google Scholar
  • Huston, M.A. 1994. BiologicaL Diversity: The Coexistence of Species on Changing Landscapes . Cambridge University Press, Cambridge.

    Huston M.A. , '', in BiologicaL Diversity: The Coexistence of Species on Changing Landscapes , (1994 ) -.

  • Huston, M.A. 1999. Local processes and regional patterns: appropriate scales for understanding variation in the diversity of plants and animals Oikos 86: 393–401.

    Huston M.A. , 'Local processes and regional patterns: appropriate scales for understanding variation in the diversity of plants and animals ' (1999 ) 86 Oikos : 393 -401.

    • Search Google Scholar
  • Kawai, T. and M. Tokeshi. 2007. Testing the facilitation-competition paradigm under the stress-gradient hypothesis: decoupling multiple stress factors. Proc. Roy. Soc. B. 274: 2503–2508.

    Tokeshi M. , 'Testing the facilitation-competition paradigm under the stress-gradient hypothesis: decoupling multiple stress factors ' (2007 ) 274 Proc. Roy. Soc. B. : 2503 -2508.

    • Search Google Scholar
  • Koukoura, Z. and A. Kyriazopoulos. 2007. Adaptation of herbaceous plant species in the understory of Pinus brutia . Agroforest. Syst. 70: 11–16.

    Kyriazopoulos A. , 'Adaptation of herbaceous plant species in the understory of Pinus brutia ' (2007 ) 70 Agroforest. Syst. : 11 -16.

    • Search Google Scholar
  • Lande, R. 1996. Statistics and partitioning of species diversity, and similarities among multiple communities. Oikos 76: 5–13.

    Lande R. , 'Statistics and partitioning of species diversity, and similarities among multiple communities ' (1996 ) 76 Oikos : 5 -13.

    • Search Google Scholar
  • Lepš, J. and P. Šmilauer. 2003. Multivariate Analysis of Ecological Data Using CANOCO . Cambridge University Press, Cambridge.

    Šmilauer P. , '', in Multivariate Analysis of Ecological Data Using CANOCO , (2003 ) -.

  • Liancourt, P., R.M. Callaway and R. Michalet. 2005. Stress tolerance and competitive — response ability determine the outcome of biotic interaction. Ecology 86: 1611–1618.

    Michalet R. , 'Stress tolerance and competitive — response ability determine the outcome of biotic interaction ' (2005 ) 86 Ecology : 1611 -1618.

    • Search Google Scholar
  • López, R.P., D.M. Larrea-Alzácar and T. Ortuño. 2009. Positive effects of shrubs on herbaceous species richness across several spatial scales: evidence from the semiarid Andean subtropics. J. Veg. Sci. 20:728–734.

    Ortuño T. , 'Positive effects of shrubs on herbaceous species richness across several spatial scales: evidence from the semiarid Andean subtropics ' (2009 ) 20 J. Veg. Sci. : 728 -734.

    • Search Google Scholar
  • López-Pintor, A., T. Espigares and J.M. Benayas. 2003. Spatial segregation of plant species caused by Retama sphaerocarpa influence in a Mediterranean pasture: a perspective fromthe soil seed bank. Plant Ecol. 167: 107–116.

    Benayas J.M. , 'Spatial segregation of plant species caused by Retama sphaerocarpa influence in a Mediterranean pasture: a perspective fromthe soil seed bank ' (2003 ) 167 Plant Ecol. : 107 -116.

    • Search Google Scholar
  • López-Pintor, A., A. Gómez-Sal and J.M. Rey-Benayas. 2006. Shrubs as a source of spatial heterogeneity — the case of Retama sphaerocarpa in Mediterranean pastures of Central Spain. Acta Oecol. 29: 247–255.

    Rey-Benayas J.M. , 'Shrubs as a source of spatial heterogeneity — the case of Retama sphaerocarpa in Mediterranean pastures of Central Spain ' (2006 ) 29 Acta Oecol. : 247 -255.

    • Search Google Scholar
  • Maestre, F.T., F. Valladares and J.F. Reynolds. 2005. Is the change of plant — plant interactions with abiotic stress predictable? A meta — analysis of field results in arid environments. J. Ecol. 93: 748–757.

    Reynolds J.F. , 'Is the change of plant — plant interactions with abiotic stress predictable? A meta — analysis of field results in arid environments ' (2005 ) 93 J. Ecol. : 748 -757.

    • Search Google Scholar
  • Moir, W.H. 1966. Influence of Ponderosa Pine on herbaceous vegetation. Ecology 47: 1045–1048.

    Moir W.H. , 'Influence of Ponderosa Pine on herbaceous vegetation ' (1966 ) 47 Ecology : 1045 -1048.

    • Search Google Scholar
  • Moro, M.J., F.I. Pugnaire, P. Haase and J. Puigdefabregas. 1997. Mechanisms of interaction between Retama sphaerocarpa and its understory layer in a semi — arid environment. Ecography 20: 175–184.

    Puigdefabregas J. , 'Mechanisms of interaction between Retama sphaerocarpa and its understory layer in a semi — arid environment ' (1997 ) 20 Ecography : 175 -184.

    • Search Google Scholar
  • Pausas, J.G., C. Bladè, A. Valdecantos, J.P. Seva, D. Fuentes, J.A. Alloza, A Milagrosa, S. Bautista, J. Cortina and R. Vallejo. 2004. Pines and oaks in the restoration of Mediterranean landscapes of Spain: new perspectives for an old practice — a review. Plant Ecol. 171: 209–220.

    Vallejo R. , 'Pines and oaks in the restoration of Mediterranean landscapes of Spain: new perspectives for an old practice — a review ' (2004 ) 171 Plant Ecol. : 209 -220.

    • Search Google Scholar
  • Pugnaire F.I., P. Haase, J. Puigdefábregas, M. Cueto, S.C. Clark and L.D. Incoll. 1996. Facilitation and succession under the leguminous shrub, Retama sphaerocarpa in a semi-arid environment in south-east Spain. Oikos 76: 455–464.

    Incoll L.D. , 'Facilitation and succession under the leguminous shrub, Retama sphaerocarpa in a semi-arid environment in south-east Spain ' (1996 ) 76 Oikos : 455 -464.

    • Search Google Scholar
  • Pugnaire, F.I. and R. Lázaro. 2000. Seedbank and understorey species composition in a semiarid environment: the effect of shrub age and rainfall. Ann. Bot.-London 86: 807–813.

    Lázaro R. , 'Seedbank and understorey species composition in a semiarid environment: the effect of shrub age and rainfall ' (2000 ) 86 Ann. Bot.-London : 807 -813.

    • Search Google Scholar
  • Pugnaire, F.I. and M.T. Luque. 2001. Changes in plant interactions along a gradient of environmental stress. Oikos 93: 42–49.

    Luque M.T. , 'Changes in plant interactions along a gradient of environmental stress ' (2001 ) 93 Oikos : 42 -49.

    • Search Google Scholar
  • Pugnaire, F.I., C. Armas and R. Tirado. 2001. Capítulo 8: Balance de las interacciones entre las plantas en ambientes mediterráneos. In: Zamora, R. and F.I. Pugnaire (eds.). Ecosistemas Mediterráneos: Análisis Funcional . Consejo Superior de Investigaciones Científicas-Asociación Española de Ecología Terrestre, Granada. pp 213–235.

    Tirado R. , '', in Ecosistemas Mediterráneos: Análisis Funcional , (2001 ) -.

  • Salvador, L., R. Alía, D. Agúndez and L. Gil. 2000. Genetic variation and migration pathways of maritime pines ( Pinus pinaster Aiton) in the Iberian Peninsula. Theor. Appl. Gent. 100: 89–95.

    Gil L. , 'Genetic variation and migration pathways of maritime pines (Pinus pinaster Aiton) in the Iberian Peninsula ' (2000 ) 100 Theor. Appl. Gent. : 89 -95.

    • Search Google Scholar
  • ter Braak, C.J.F. and P. Šmilauer. 2002. CANOCO 4.5 reference manual and CanoDraw for Windows. User’s guide to Canoco for Windows: software for canonical community ordination . Microcomputer Power, Ithaca.

    Šmilauer P. , '', in CANOCO 4.5 reference manual and CanoDraw for Windows. User’s guide to Canoco for Windows: software for canonical community ordination , (2002 ) -.

  • Termiño, J., J.F. García-Hidalgo and M. Segura. 1997. Caracterización y evolución geológica del sistema dunas — humedales de Cantalejo (Segovia). Estudios Geológicos 53: 135–143.

    Segura M. , 'Caracterización y evolución geológica del sistema dunas — humedales de Cantalejo (Segovia) ' (1997 ) 53 Estudios Geológicos : 135 -143.

    • Search Google Scholar
  • Tewksbury, J.J. and J.D. Lloyd. 2001. Positive interactions under nurse plant: spatial scale, stress gradients and benefactor size. Oecologia 127: 425–434.

    Lloyd J.D. , 'Positive interactions under nurse plant: spatial scale, stress gradients and benefactor size ' (2001 ) 127 Oecologia : 425 -434.

    • Search Google Scholar
  • Veech, J.A. and T.O. Crist. 2009a. Partition 3.0 user’s manual (unpublished manual) ( http://www.users.muohio.edu/cristto/partition.htm )

  • Veech, J.A. and T.O. Crist. 2009b. PARTITION: software for hierarchical partitioning of species diversity, version 3.0. ( http://www.users.muohio.edu/cristto/partition.htm )

  • Wagner, H., O. Wildi and K.C. Ewald. 2000. Additive partitioning of plant species diversity in an agricultural mosaic landscape. Landscape Ecol. 15: 219–227.

    Ewald K.C. , 'Additive partitioning of plant species diversity in an agricultural mosaic landscape ' (2000 ) 15 Landscape Ecol. : 219 -227.

    • Search Google Scholar
  • Weedon J.T. and J.M. Facelli. 2008. Desert shrubs have negative or neutral effects on annuals at two levels of water availability in arid lands of South-Australia. J. Ecol. 96: 1230–1237.

    Facelli J.M. , 'Desert shrubs have negative or neutral effects on annuals at two levels of water availability in arid lands of South-Australia ' (2008 ) 96 J. Ecol. : 1230 -1237.

    • Search Google Scholar