Herbívoros introducidos y el efecto Allee en plantas polinizadas por animales

  • Diego P. Vázquez Instituto Argentino de Investigaciones de las Zonas Áridas, Centro Regional de Investigaciones Científicas y Tecnológicas, CONICET, Mendoza, Argentina
Palabras clave: abundancia, efecto Allee, densodependencia, herbíviros introducidos, mutualismo, reproducción de plantas, polinización, especialización y generalización de polinizadores, dinámica poblacional

Resumen

Las interacciones interespecíficas pueden ser moduladas por el contexto comunitario en el que ocurren. Este artículo estudia las interacciones planta-polinizador y su modulación por herbívoros introducidos mediante cambios en la densidad poblacional de las plantas. En primer lugar desarrollo un modelo matemático que relaciona la densidad poblacional de una planta polinizada por animales con la frecuencia de visitas por polinizadores, la polinización, la reproducción y la tasa per capita de crecimiento poblacional. Este modelo me permite investigar la influencia de varios parámetros relacionados con la polinización—incluyendo la abundancia relativa de la especie focal, la especialización de los polinizadores, la cantidad y la calidad de la polinización y la limitación por polen de la reproducción—sobre la relación entre la tasa per capita de crecimiento y la densidad poblacional. Luego utilizo este marco teórico para discutir dos estudios de caso que han evaluado los efectos mediados por la densidad de los herbívoros introducidos sobre la reproducción de las plantas. Este ejercicio me permite señalar algunas limitaciones de los estudios previos y sugerir direcciones para investigaciones futuras.

Citas

AGUILAR, R & L GALETTO. 2004. Effects of forest fragmentation on male and female reproductive success in Cestrum parqui (Solanaceae). Oecologia, 138:513–520.

AIZEN, MA. 1997. Influence of local floral density and sex ratio on pollen receipt and seed output: empirical and experimental results in dichogamous Alstroemeria aurea (Alstroemeriaceae). Oecologia, 111: 404–412.

AIZEN, MA. 2001. Flower sex ratio, pollinator abundance, and the seasonal pollination dynamics of a protandrous plant. Ecology, 82: 127–144.

AIZEN, MA & A BASILIO. 1995. Within and among flower sex-phase distribution in Alstroemeria aurea (Alstroemeriaceae). Canadian Journal of Botany, 73:1986–1994.

AIZEN, MA & P FEINSINGER. 1994a. Forest fragmentation, pollination, and plant reproduction in a Chaco dry forest, Argentina. Ecology, 75: 330–351.

AIZEN, MA & P FEINSINGER. 1994b. Habitat fragmentation, native insect pollinators, and feral honey bees in Argentine Chaco Serrano. Ecological Applications, 4:378–392.

AIZEN, MA & LD HARDER. 2007. Expanding the limits of the pollen-limitation concept: effects of pollen quantity and quality. Ecology, 88:271–281.

AIZEN, MA & DP VÁZQUEZ. 2006. Flower perfor- mance in human-altered habitats. Pp. 159–179 in: LD Harder & SCH Barrett (eds). Ecology and Evolution of Flowers. Oxford University Press.

ALLEE, WC; AE EMERSON & O PARK. 1949. Princples of Animal Ecology. W.B. Saunders Co., Philadelphia.

ASHWORTH, L; R AGUILAR; L GALETTO & MA AIZEN. 2004. Why do pollination generalist and specialist plant species show similar reproductive susceptibility to habitat fragmentation? Journal of Ecology, 92:717–719.

BOND, WJ. 1994. Do mutualisms matter? Assessing the impact of pollinator and disperser disruption on plant extinction. Philosophical Transactions of the Royal Society of London Series B, 344:83–90.

CAMPOS, CM & RA OJEDA. 1997. Dispersal and germination of Prosopis flexuosa (Fabaceae) seeds by desert mammals in Argentina. Journal of Arid Environments, 35:707–714.

CASWELL, H. 2001. Matrix Population Models: Construction, Analysis, and Interpretation. Sinauer Associates, Suntherland, MA. COURCHAMP, F; T CLUTTON-BROCK & B GRENFELL. 1999.

Inverse density dependence and the Allee effect. Trends in Ecology & Evolution, 14:405–410.

CRAWLEY, MJ (ed.). 1997. Plant Ecology. Second ed. Blackwell Science, Oxford.

DARWIN, C. 1859. The Origin of Species by Means of Natural Selection. Bantam, New York, U.S.A.

DE VOS, A; RH MANVILLE & RG VAN GELDER. 1956. Introduced mammals and their influence on native biota. Zoologica (New York Zoological Society), 41:163–194.

DENNIS, B. 1989. Allee effects: population growth, critical density, and the chance of extinction. Natural Resource Modeling, 3:481–538.

EBENHARD, T. 1988. Introduced birds and mammals and their ecological effects. Swedish Wildlife Research (Viltrevy), 13:1–107.

GHAZOUL, J. 2005. Pollen and seed dispersal among dispersed plants. Biological Reviews, 80:1–31.

HIXON, MA; SW PACALA & SA SANDIN. 2002. Population regulation: historical context and contemporary challenges of open vs. closed systems. Ecology, 83:1490–1508.

KOT, M. 2001. Elements of Mathematical Ecology. Cambridge University Press.

KUNIN, W & Y IWASA. 1996. Pollinator foraging strategies in mixed floral arrays: density effects and floral constancy. Theoretical Population Biology, 49:232–263.

KUNIN, WE. 1993. Sex and the single mustard: population density and pollinator behavior effects on seed-set. Ecology, 74:2145–2160.

KUNIN, WE. 1997a. Population biology of rarity: on the complexity of density dependence in insect-plant interactions. Pp. 150–173 in: WE Kunin & KJ Gaston (eds). The Biology of Rarity. Chapman and Hall, London.

KUNIN, WE. 1997b. Population size and density effects in pollination: pollinator foraging and plant reproductive success in experimental arrays of Brassica kaber. Journal of Ecology, 85:225–234.

LANDE, R. 1988. Genetics and demography in biological conservation. Science, 241:1455–1459.

LAWTON, JH. 1999. Are there general laws in ecology? Oikos, 84:177–192.

MALTHUS, TR. 1798. An essay on the Principle of Population, as it affects the future improvement of society, with remarks on the speculations of Mr. Godwin, M. Concorcet, and other writers. J. Johnson.

MASUELLI, R & O BALBOA. 1989. Self-incompatibility in Prosopis flexuosa D.C. Plant Cell Imcompatibility Newsletter, 21: 44–48.

MCCARTHY, M. 1997. The Allee effect, finding mates and theoretical models. Ecological Modelling, 103:99–102.

MILESI, FA & J LÓPEZ DE CASENAVE. 2004. Unexpected relationships and valuable mistakes: nonmyrmecochorous Prosopis dispersed by messy leaf- cutting ants in harvesting their seeds. Austral Ecology, 29: 558–567.

MORALES, CL. 2007. Introducción de abejorros (Bombus) no nativos: causas, consecuencias ecológicas y perspectivas. Ecología Austral, 17: 51-65.

MORALES, CL & MA AIZEN. 2002. Does invasion of exotic plants promote invasion of exotic flower visitors? A case study from the temperate forests of the southern Andes. Biological Invasions, 4: 87–100.

MORRIS, WF. 2003. Which mutualists are most essential? Buffering of plant reproduction against the extinction of pollinators. Pp. 260–280 in: P Kareiva & SA Levin (eds). The Importance of Species: Perspectives on Expendability and Triage. Princeton University Press, Princeton.

RATHCKE, B. 1983. Competition and facilitiation among plants for pollination. Pp. 305–329 in: L Real (ed). Pollination Biology. Academic Press, London.

ROSSI, BE & PE VILLAGRA. 2003. Effects of Prosopis flexuosa on soil properties and the spatial pattern of understorey species in arid Argentina. Journal of Vegetation Science, 14:543–550. Article.

SOUTO, CP; MA AIZEN & AC PREMOLI. 2002. Effects of crossing distance and genetic relatedness on pollen performance in Alstroemeria aurea (Alstroemeriaceae). American Journal of Botany, 89:427–432.

STEPHENS, PA & WJ SUTHERLAND. 1999. Consequences of the Allee effect for behaviour, ecology and conservation. Trends in Ecology & Evolution, 14:401–405.

TRAVESET, A & DM RICHARDSON. 2006. Biological inva- sions as disruptors of plant reproductive mutualisms. Trends in Ecology & Evolution, 21: 208–216.

TURCHIN, P. 2001. Does population ecology have general laws? Oikos, 94:17–26.

VERHULST, PF. 1845. Recherches mathématiques sur la loi d’accroissement de la population. Nouveaux Mémoires de l’Académie Royale des Sciences et Belles-
Lettres de Bruxelles, 18:3–38.

VÁZQUEZ, DP. 2002. Multiple effects of introduced mammalian herbivores in a temperate forest. Biological Invasions, 4:175–191.

VÁZQUEZ, DP; WF MORRIS & P JORDANO. 2005. Interaction frequency as a surrogate for the total effect of animal mutualists on plants. Ecology Letters, 8:1088–1094.

VÁZQUEZ, DP & D SIMBERLOFF. 2002. Ecological specialization and susceptibility to disturbance: conjectures and refutations. American Naturalist, 159:606–623.

VÁZQUEZ, DP & D SIMBERLOFF. 2004. Indirect effects of an introduced ungulate on pollination and reproduction. Ecological Monographs, 74:281–308.

WASER, NM; L CHITTKA; MV PRICE; NM WILLIAMS & J OLLERTON. 1996. Generalization in pollination systems, and why it matters. Ecology, 77:1043–1060.

WASER, NM & J OLLERTON (eds.). 2006. Plant– Pollinator Interactions: From Specialization to Generalization. University of Chicago Press.
Publicado
2007-06-01
Sección
Sección Especial