Skip to main content Accessibility help
×
×
Home

Climate and grazing control nurse effects in an Ecuadorian dry shrubby community

  • Carlos Iván Espinosa (a1), Arantzazu L. Luzuriaga (a2), Marcelino de la Cruz (a2) and Adrián Escudero (a2)

Abstract:

Positive plant interactions have strong effects on plant diversity at several spatial scales, expanding species distribution under stressful conditions. We evaluated the joint effect of climate and grazing on the nurse effect of Croton wagneri, by monitoring several community attributes at two spatial scales: microhabitat and plant community. Two very close locations that only differed in grazing intensity were surveyed in an Ecuadorian dry scrub ecosystem. At each location, two 30 × 30-m plots were established at four altitudinal levels (1500, 2630, 1959 and 2100 m asl) and 40 microsites were surveyed in each plot. Croton wagneri acted as community hubs, increasing species richness and plant cover at both scales. Beneath nurses mean richness and cover values were 3.4 and 21.9%, and in open areas 2.3 and 4.5%, respectively. Magnitude of nurse effect was dependent on climate and grazing conditions. In ungrazed locations, cover increased and diversity reduced with altitude, while grazed locations showed the opposite trend. In ungrazed plots the interactions shifted from positive to negative with altitude, in grazed locations interactions remained positive. We conclude that the nurse effect is a key mechanism regulating community properties not only at microsite but also at the entire community scale.

Copyright

Corresponding author

1Corresponding author. Email: ciespinosa@utpl.edu.ec

References

Hide All
AGUIAR, M. R. & SALA, O. E. 1999. Patch structure, dynamics and implications for the functioning of arid ecosystems. Trends in Ecology and Evolution 14:273277.
ARMAS, C., ORDIALES, R. & PUGNAIRE, F. I. 2004. Measuring plant interactions: a new comparative index. Ecology 85:26822686.
ARMAS, C., PUGNAIRE, F. I. & SALA, O. E. 2008. Patch structure dynamics and mechanisms of cyclical succession in a Patagonian steppe (Argentina). Journal of Arid Environments 72:15521561.
BATES, D. M. & CHAMBERS, J. M. 1992. Nonlinear models. Pp. 421454 in Chambers, J. M. & Hastie, T. J. (eds.). Statistical models in S. Wadsworth & Brooks/Cole, Pacific Grove.
BOWERS, J. 2005. Influence of climatic variability on local population dynamics of a Sonoran Desert Platyopuntia. Journal of Arid Environments 61:193210.
CALLAWAY, R. M. 1997. Positive interactions in plant communities and the individualistic-continuum concept. Oecologia 112:143149.
CALLAWAY, R. M. 2007. Positive interactions and interdependence in plant communities. Springer, Dordrecht. 415 pp.
CAVIERES, L. A. & BADANO, E. I. 2009. Do facilitative interactions increase species richness at the entire community level? Journal of Ecology 97:11811191.
CAVIERES, L. A., BADANO, E. I., SIERRA-ALMEIDA, A., GÓMEZ-GONZÁLEZ, S. & MOLINA-MONTENEGRO, M. A. 2006. Positive interactions between alpine plant species and the nurse cushion plant Laretia acaulis do not increase with elevation in the Andes of central Chile. New Phytologist 169:5969.
CHOLER, P., MICHALET, R. & CALLAWAY, R. M. 2001. Facilitation and competition on gradients in alpine plant communities. Ecology 82:32953308.
CRAIN, C. M. & BERTNESS, M. D. 2006. Ecosystem engineering across environmental gradients: implications for conservation and management. BioScience 56:211218.
ESCUDERO, A., GIMÉNEZ-BENAVIDES, L., IRIONDO, J. M. & RUBIO, A. 2004. Patch dynamics and islands of fertility in a high mountain Mediterranean community. Arctic, Antarctic, and Alpine Research 36:518527.
ESPINOSA, C. I., CABRERA, O., LUZURIAGA, A. L. & ESCUDERO, A. 2011. What factors affect diversity and species composition of endangered Tumbesian dry forests in southern Ecuador? Biotropica 43:1522.
ESPINOSA, C. I., LUZURIAGA, A. L., DE LA CRUZ, M., MONTERO, M. & ESCUDERO, A. 2013. Co-occurring grazing and climate stressors have different effects on the total seed bank when compared to the persistent seed bank. Journal of Vegetation Science. DOI: 10.1111/jvs.12043.
GRAFF, P., AGUIAR, M. R. & CHANETON, E. J. 2007. Shifts in positive and negative plant interactions along a grazing intensity gradient. Ecology 88:188199.
GRIME, J. P. 1973. Competitive exclusion in herbaceous vegetation. Nature 242:344347.
GUIJARRO, J. 2011. User´s guide to climatol. Agency of State Meteorological Office, Balearic Islands. 33 pp.
HACKER, S. D. & GAINES, S. D. 1997. Some implications of direct positive interactions for community species diversity. Ecology 78:19902003.
JOST, L. 2006. Entropy and diversity. Oikos 113:363375.
KÖRNER, C. & PAULSEN, J. 2004. A world-wide study of high altitude treeline temperatures. Journal of Biogeography 31:713732.
LEGENDRE, P. & LEGENDRE, L. 1998. Numerical ecology. Elsevier, Amsterdam. 853 pp.
MAALOUF, J. P., LE BAGOUSSE-PINGUET, Y., MARCHAND, L., BÂCHELIER, E., TOUZARD, B. & MICHALET, R. 2012. Integrating climate change into calcareous grassland management. Journal of Applied Ecology 49:795802.
MAESTRE, F. & CORTINA, J. 2005. Remnant shrubs in Mediterranean semi-arid steppes: effects of shrub size, abiotic factors and species identity on understorey richness and occurrence. Acta Oecologica 27:161169.
MAESTRE, F. T. & ESCUDERO, A. 2009. Is the patch size distribution of vegetation a suitable indicator of desertification processes? Ecology 90:17291735.
MAESTRE, F. T., VALLADARES, F. & REYNOLDS, J. F. 2005. Is the change of plant–plant interactions with abiotic stress predictable? A meta-analysis of field results in arid environments. Journal of Ecology 93:748757.
MAESTRE, F. T., CALLAWAY, R. M., VALLADARES, F. & LORTIE, C. J. 2009. Refining the stress-gradient hypothesis for competition and facilitation in plant communities. Journal of Ecology 97:199205.
MICHALET, R., BROOKER, R. W., CAVIERES, L. A., KIKVIDZE, Z., LORTIE, C. J., PUGNAIRE, F. I., VALIENTE-BANUET, A. & CALLAWAY, R. M. 2006. Do biotic interactions shape both sides of the humped-back model of species richness in plant communities? Ecology Letters 9:767–73.
MITTELBACH, G. G., STEINER, C. F., SCHEINER, S. M., GROSS, K. L., REYNOLDS, H. L., WAIDE, R. B., DODSON, S. I. & GOUGH, L. 2001. What is the observed relationship between species richness and productivity? Ecology 82:23812396.
OESTERHELD, M. & OYARZÁBAL, M. 2004. Grass-to-grass protection from grazing in a semi-arid steppe. Facilitation, competition and mass effect. Oikos 107:576582.
O'HARA, R. B. & KOTZE, D. J. 2010. Do not log-transform count data. Methods in Ecology and Evolution 1:118122.
PINHEIRO, J. C. & BATES, D. M. 2000. Mixed-Effects Models in S and S-PLUS. Springer, New York. 530 pp.
RUYLE, G. B. & DWYER, D. D. 1985. Feeding stations of sheep as an indicator of diminished forage supply. Journal of Animal Sciences 61:349353.
SCHEINER, S. M. & JONES, S. 2002. Diversity, productivity and scale in Wisconsin vegetation. Evolutionary Ecology Research 4:10971117.
SENFT, R. L., COUGHENOUR, M. B., BAILEY, D. W., RITTENHOUSE, L. R., SALA, O. E. & SWIFT, D. M. 1987. Large herbivore foraging and ecological hierarchies. BioScience 37:789799.
SIERRA, R. 1999. Propuesta preliminar de un sistema de clasificación de vegetación para el Ecuador continental. Proyecto INEFAN/GEF-BIRF y EcoCiencia, Quito. 193 pp.
SOLIVERES, S., ELDRIDGE, D. J., MAESTRE, F. T., BOWKER, M. A., TIGHE, M. & ESCUDERO, A. 2011. Microhabitat amelioration and reduced competition among understorey plants as drivers of facilitation across environmental gradients: towards a unifying framework. Perspectives in Plant Ecology, Evolution and Systematics 13:247258.
TEWKSBURY, J. J. & LLOYD, J. D. 2001. Positive interactions under nurse-plants: spatial scale, stress gradients and benefactor size. Oecologia 127:425434.
TONGWAY, D. J. & HINDLEY, N. L. 2004. Landscape Function Analysis: procedures for monitoring and assessing landscapes. With special reference to minesites and rangelands. CSIRO Sustainable Ecosystems, Canberra. 82 pp.
ULLOA, C. & JØRGENSEN, P. M. 1995. Árboles y arbustos de los Andes del Ecuador. Department of Systematic Botany. Aarhus University. 264 pp.
WALTER, H. & LIETH, H. 1960. Klimadiagramm Weltatlas. G. Fischer, Jena. 253 pp.
WARREN, R. J. 2010. An experimental test of well-described vegetation patterns across slope aspects using woodland herb transplants and manipulated abiotic drivers. New Phytologist 185:10381049.
WHITE, H. 1996. Estimation, inference and specification analysis. Cambridge University Press, Cambridge. 396 pp.
XU, J., MICHALET, R., ZHANG, J. L., WANG, G., CHU, C. J. & XIAO, S. 2010. Assessing facilitative responses to a nurse shrub at the community level: the example of Potentilla fruticosa in a sub-alpine grassland of northwest China. Plant Biology 12:780787.
Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

Journal of Tropical Ecology
  • ISSN: 0266-4674
  • EISSN: 1469-7831
  • URL: /core/journals/journal-of-tropical-ecology
Please enter your name
Please enter a valid email address
Who would you like to send this to? *
×

Keywords

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed