Resumen

ALMIRON, Martín  y  MARTINEZ CARRETERO, Eduardo. Echinopsis leucantha (Gillies ex Salm-Dyck) Walp. (Cactoideae): Interactions with nurse plants in the central argentine desert. Multequina [online]. 2010, vol.19, n.2, pp. 77-87. ISSN 1852-7329.

In this study we examined the spatial distribution of E. leucantha, through the analysis of bivariate spatial patterns, with respect to available installation sites under bushes in three different physiographic units (geotopes). The influence of shrubs in the photosynthetic active radiation and temperature at ground level was evaluated. A lower scales (0 to 1.6 m) E. leucantha was associated in three geotopes with Larrea cuneifolia and/or Zuccagnia punctata. Regarding to these shrubs, the association found showed a high relation to the gradient of photosynthetic active solar radiation found recorded from the center to the periphery of the bushes. In relation to other shrubs the distribution was random. The effect of shrubs on soil temperature did not influence in the spatial distribution of E. leucantha.

Palabras llave : Interespecific associations; Environmental heterogeneity; Wiegand- Moloney's O(r) statistic.