Skip to main content Accessibility help

Invasibility Patterns of Knotgrass (Paspalum distichum) in Portuguese Riparian Habitats

  • Francisca C. Aguiar (a1), M. Teresa Ferreira (a1), António Albuquerque (a1) and Ivan Bernez (a2)


Spatial patterns of the exotic riverine knotgrass (Paspalum distichum L.) were examined in Mediterranean river basins in Southwestern Iberia. The major goals of this study were to assess the degree of invasibility of riparian habitats by this species and to determine the influence of environmental factors and human-induced disturbances that this knotgrass has on both the landscape and the habitat scales. The present study demonstrates the ability of knotgrass to invade riparian habitats in Portuguese freshwater ecosystems. However, most of the spatial variation of the knotgrass cover seemed to be driven by local factors, such as fine sediment enrichment and the fragmentation of riparian woods, and by other anthropogenic interferences in relation to both the fluvial system and the surrounding landscape.


Corresponding author

Corresponding author's E-mail:


Hide All
Aguiar, F., Moreira, I., and Ferreira, M. T. 1996. A percepção da vegetação aquática infestante pelas entidades gestoras dos recursos hídricos (English abstract title: Perception of aquatic weed problems in Portugal by water resources managers). Rev. Cienc. Agrar. 19:3556.
Aguiar, F. C., Ferreira, M. T., and Moreira, I. 2001. Exotic and native vegetation establishment following channelization of a western Iberian river. Regul. Rivers Res. Manag. 17:509526.
Braun-Blanquet, J. 1932. Plant Sociology: The Study of Plant Communities (English translation). New York: McGraw-Hill.
Costa, J. C., Capelo, J., Espírito-Santo, M. D., Lous&atilde, M., Monteiro, A., Mesquita, S., Vasconcelos, M. T., and Moreira, I. 1999. Plant communities of the lagoons of the Portuguese Coastal Superdistrict—a multivariate approach. Hydrobiologia 415:6775.
Dawson, F. H. and Kern-Hansen, U. 1978. Aquatic weed management in natural streams: the effect of shade by the marginal vegetation. Verh. Internat. Verein. Limnol. 20:14291434.
DiTomaso, J. M. and Healy, E. A. 2002. Aquatic and Riparian Weeds of the West. Publ. 3421. Oakland, CA: University of California Agriculture and Natural Resources.
Ferreira, M. T., Albuquerque, A., Aguiar, F. C., and Catarino, L. F. 2001. Seasonal and yearly variations of macrophytes in a southern Iberian river. Verh. Internat. Verein. Limnol. 27:38333837.
Ferreira, M. T., Albuquerque, A., Aguiar, F. C., and Sidorkewicz, N. 2002. Assessing reference sites and ecological quality of river plant assemblages from an Iberian basin using a multivariate approach. Arch. HydroBiol. 155:121145.
Ferreira, M. T. and Moreira, I. S. 1995. The invasive component of a river flora under the influence of Mediterranean agricultural systems. in Pysek, P., Prach, K., Rejmanek, M., and Wade, M., eds. Plant Invasions— General Aspects and Special Problems. Amsterdam: SPB Academic. Pp. 117127.
Franco, J. A. and Rocha-Afonso, M. L. 1980. Distribuição em Portugal das principais infestantes. in Proceeding of the I Congresso de Fitiatria e Fitofarmacologia, Lisboa. Pp. 122.
Franco, J. A. and Rocha-Afonso, M. L. 1998. Nova Flora de Portugal (Continente e Açores). 3. Gramineae. Lisboa: Escolar Editora.
Gasith, A. and Resh, V. H. 1999. Streams in Mediterranean climate regions: abiotic influences and biotic responses to predictable seasonal events. Annu. Rev. Ecol. Syst. 30:5181.
Guillerm, J. L., Le Floc'h, E., Maillet, J., and Boulet, C. 1990. The invading weeds within the Western Mediterranean Basin. in di Castri, F., Hansen, A. J., and Debussche, M., eds. Biological Invasions in Europe and in the Mediterranean Basin. Dordrecht: Kluwer. Pp. 6184.
Huang, W. Z., Hsiao, A. I., and Jordan, L. 1987. Effects of temperature, light and certain growth regulation substances on sprouting, rooting and growth of single-node rhizome and shoot segments of Paspalum distichum L. Weed Res. 27:5767.
Le Floc'h, E. 1991. Invasive plants of the Mediterranean Basin. in Groves, R. H. and de Castri, F., eds. Biogeography of the Mediterranean Invasions. Cambridge, U.K.: Cambridge University Press. Pp. 6780.
Liu, S. H., Hsiao, A. I., and Quick, W. A. 1991. The influence of leaf blade, nutrients, water and light on the promotion of axillary bud growth of isolated single-node stem segments of Paspalum distichum L. Weed Res. 31:385394.
McIntyre, S. and Lavorel, S. 1994. Predicting richness of native, rare and exotic plants in response to habitat and disturbance variables across a variegated landscape. Conserv. Biol. 8:521531.
Ministério do Ambiente. 1999. Decreto-Lei n° 565/99 de 21-12-1999, Espé cies não indígenas da flora e da fauna. Diário Repub. I Ser. A. 295:91009114.
Mouw, J. E. B. and Alaback, P. B. 2003. Putting floodplain hyperdiversity in a regional context: an assessment of terrestrial-floodplain connectivity in a montane environment. J. Biogeogr. 30:87103.
P-Clima. 1999. Software Provedor de Dados Climatológicos para Portugal. Version 1.2. Aguiar, R., ed. Projecto ALTENER XVII/4.1013/Z/96-092. Lisbon, Portugal: INETI/DER.
Planty-Tabacchi, A. M., Tabacchi, E., Naiman, R. J., De Ferrari, C., and Décamps, H. 1996. Invasibility of species-rich community in riparian zones. Conserv. Biol. 10:598607.
Raunkiaer, C. 1934. The Life Forms of Plants and Statistical Geography. Oxford, UK: Clarendon.
Sampaio, G. 1909. Flora Portuguesa. Porto: Imprensa Moderna.
Silva, A. R. P. 1940. O género Paspalum em Portugal. Agron. Lusit. 2:523.
Strahler, A. N. 1957. Quantitative analysis of watershed geomorphology. Trans. Am. Geophys. Union 38:913920.
Vasconcelos, T., Tavares, M., and Gaspar, N. 1999. Aquatic plants in the rice fields of the Tagus Valley, Portugal. Hydrobiologia 415:5965.


Related content

Powered by UNSILO

Invasibility Patterns of Knotgrass (Paspalum distichum) in Portuguese Riparian Habitats

  • Francisca C. Aguiar (a1), M. Teresa Ferreira (a1), António Albuquerque (a1) and Ivan Bernez (a2)


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.