Spatial relationships between cacti and nurse shrubs in a semi‐arid environment in central Mexico

Abstract

Abstract. The Zapotitlán de las Salinas valley, central Mexico, harbours a high diversity of cacti. Pattern analysis indicated that the establishment of two columnar cacti, Neobuxbaumia tetetzo and Cephalocereus hoppenstedtii, and of three small globose cacti, Coryphantapallida, Mammillaria colina andM casoi, is aggregated and associated with perennial nurse shrubs. Some nurse species, Castela tortuosa, Caesalpinia melanadenia and Eupatorium spinosarum have a higher number of cacti beneath their canopies than would be expected by chance. A replacement pattern was found between the columnar cacti and their nurses, an aspect which was not found with the globose cacti. Following the assumption that protection against excessive radiation is the main factor determining the nurse effect, the azimuth orientation of the cacti with respect to their nurses was evaluated. Only Coryphanta pallida presented a non‐random distribution with a tendency towards the North and West. The difference in maximum temperature between the soil surface under the different nurse species and of open spaces, which is reached at midday, was 16 °C. No significant differences were found in beneath‐canopy temperatures for the three nurse species considered. Soil nitrogen levels were significantly lower beneath the different nurse plants than in open spaces. This result suggests that soil fertility is not an important factor in the nurse‐plant phenomenon in Zapotitlán.

Cactus seed germination: a review

“…Alternatively, Cortes Figueira et al (1994) suggest that for Melocactus violaceus, shady habitats may pose restrictions on survivorship because most plants were observed in open habitats. Nurse plants are mostly perennial shrubs that, in some cases, can be replaced by the grown columnar cacti (Valiente-Banuet et al, 1991a).…”

Tamaño poblacional y características del hábitat de Mammillaria eriacantha , una cactácea endémica del centro de Veracruz, México

“…Existe evidencia de que las cactáceas tienen un patrón de distribución agregado (Godínez-Álvarez et al, 2003), probablemente debido al nodrizaje que les proporcionan algunas especies de plantas (Valiente-Banuet et al,1991;Larrea-Alcázar et al, 2005), pero esto ha sido documentado en cactáceas de ambientes secos. Si bien el bosque tropical caducifolio de la zona de estudio es una ambiente seco la mayor parte del año, es probable que su clima no sea tan extremoso como para evidenciar un patrón de distribución agregado de Mammmillaria eriacantha.…”

Environmental variables and tree population structures in deciduous forests of central Brazil with different levels of logging

“…In fact, cattle is associated to shade, where the stratum up to 1m height is less dense. Places with dense shrub vegetation, such as liana tangles, limit the movement of animals (Valiente-Banuet et al, 1991). Soil cover -There was considerable soil cover in all the fragments, so that even the smallest total soil cover was about 80% in Intact.…”