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

Published online by Cambridge University Press:  29 October 2013

Carlos Iván Espinosa*
Affiliation:
Instituto de Ecología. Universidad Técnica Particular de Loja, San Cayetano Alto, Marcelino Champagnat, Loja, Ecuador
Arantzazu L. Luzuriaga
Affiliation:
Departamento de Biología y Geología, ESCET, Universidad Rey Juan Carlos, Móstoles, E-28933, Madrid, Spain
Marcelino de la Cruz
Affiliation:
Departamento de Biología y Geología, ESCET, Universidad Rey Juan Carlos, Móstoles, E-28933, Madrid, Spain
Adrián Escudero
Affiliation:
Departamento de Biología y Geología, ESCET, Universidad Rey Juan Carlos, Móstoles, E-28933, Madrid, Spain
*
1Corresponding author. Email: ciespinosa@utpl.edu.ec

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.

Type
Research Article
Copyright
Copyright © Cambridge University Press 2013 

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References

LITERATURE CITED

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.CrossRefGoogle ScholarPubMed
ARMAS, C., ORDIALES, R. & PUGNAIRE, F. I. 2004. Measuring plant interactions: a new comparative index. Ecology 85:26822686.CrossRefGoogle Scholar
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.CrossRefGoogle Scholar
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.Google Scholar
BOWERS, J. 2005. Influence of climatic variability on local population dynamics of a Sonoran Desert Platyopuntia. Journal of Arid Environments 61:193210.CrossRefGoogle Scholar
CALLAWAY, R. M. 1997. Positive interactions in plant communities and the individualistic-continuum concept. Oecologia 112:143149.CrossRefGoogle ScholarPubMed
CALLAWAY, R. M. 2007. Positive interactions and interdependence in plant communities. Springer, Dordrecht. 415 pp.Google Scholar
CAVIERES, L. A. & BADANO, E. I. 2009. Do facilitative interactions increase species richness at the entire community level? Journal of Ecology 97:11811191.CrossRefGoogle Scholar
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.CrossRefGoogle Scholar
CHOLER, P., MICHALET, R. & CALLAWAY, R. M. 2001. Facilitation and competition on gradients in alpine plant communities. Ecology 82:32953308.CrossRefGoogle Scholar
CRAIN, C. M. & BERTNESS, M. D. 2006. Ecosystem engineering across environmental gradients: implications for conservation and management. BioScience 56:211218.CrossRefGoogle Scholar
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.CrossRefGoogle Scholar
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.CrossRefGoogle Scholar
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.CrossRefGoogle Scholar
GRAFF, P., AGUIAR, M. R. & CHANETON, E. J. 2007. Shifts in positive and negative plant interactions along a grazing intensity gradient. Ecology 88:188199.CrossRefGoogle ScholarPubMed
GRIME, J. P. 1973. Competitive exclusion in herbaceous vegetation. Nature 242:344347.CrossRefGoogle Scholar
GUIJARRO, J. 2011. User´s guide to climatol. Agency of State Meteorological Office, Balearic Islands. 33 pp.Google Scholar
HACKER, S. D. & GAINES, S. D. 1997. Some implications of direct positive interactions for community species diversity. Ecology 78:19902003.CrossRefGoogle Scholar
JOST, L. 2006. Entropy and diversity. Oikos 113:363375.CrossRefGoogle Scholar
KÖRNER, C. & PAULSEN, J. 2004. A world-wide study of high altitude treeline temperatures. Journal of Biogeography 31:713732.CrossRefGoogle Scholar
LEGENDRE, P. & LEGENDRE, L. 1998. Numerical ecology. Elsevier, Amsterdam. 853 pp.Google Scholar
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.CrossRefGoogle Scholar
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.CrossRefGoogle Scholar
MAESTRE, F. T. & ESCUDERO, A. 2009. Is the patch size distribution of vegetation a suitable indicator of desertification processes? Ecology 90:17291735.CrossRefGoogle ScholarPubMed
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.CrossRefGoogle Scholar
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.CrossRefGoogle Scholar
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.CrossRefGoogle ScholarPubMed
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.CrossRefGoogle Scholar
OESTERHELD, M. & OYARZÁBAL, M. 2004. Grass-to-grass protection from grazing in a semi-arid steppe. Facilitation, competition and mass effect. Oikos 107:576582.CrossRefGoogle Scholar
O'HARA, R. B. & KOTZE, D. J. 2010. Do not log-transform count data. Methods in Ecology and Evolution 1:118122.CrossRefGoogle Scholar
PINHEIRO, J. C. & BATES, D. M. 2000. Mixed-Effects Models in S and S-PLUS. Springer, New York. 530 pp.CrossRefGoogle Scholar
RUYLE, G. B. & DWYER, D. D. 1985. Feeding stations of sheep as an indicator of diminished forage supply. Journal of Animal Sciences 61:349353.CrossRefGoogle Scholar
SCHEINER, S. M. & JONES, S. 2002. Diversity, productivity and scale in Wisconsin vegetation. Evolutionary Ecology Research 4:10971117.Google Scholar
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.CrossRefGoogle Scholar
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.Google Scholar
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.CrossRefGoogle ScholarPubMed
TEWKSBURY, J. J. & LLOYD, J. D. 2001. Positive interactions under nurse-plants: spatial scale, stress gradients and benefactor size. Oecologia 127:425434.CrossRefGoogle ScholarPubMed
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.Google Scholar
ULLOA, C. & JØRGENSEN, P. M. 1995. Árboles y arbustos de los Andes del Ecuador. Department of Systematic Botany. Aarhus University. 264 pp.Google Scholar
WALTER, H. & LIETH, H. 1960. Klimadiagramm Weltatlas. G. Fischer, Jena. 253 pp.Google Scholar
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.CrossRefGoogle ScholarPubMed
WHITE, H. 1996. Estimation, inference and specification analysis. Cambridge University Press, Cambridge. 396 pp.Google Scholar
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.CrossRefGoogle Scholar