The tissue water relationships of Callitris columellaris, Eucalyptus melliodora and Eucalyptus microcarpa investigated using the pressure-volume technique

Abstract

Using the pressure-bomb to construct pressure-volume curves, a cellular basis of differential drought resistance was found between Callitris columellaris (F. Muell), Eucalyptus melliodora A. Cunn. ex Schauer, and Eucalyptus microcarpa Maiden. Between these three species differences were found in bound water, relative water content and water potential at zero turgor, osmotic potential at full turgor and bulk modulus of elasticity. It is suggested that these parameters showed C. columellaris to be the most, and E. melliodora the least drought resistant of the three species.Preliminary studies also showed that drought hardening may involve an increase in bound water content, dry weight: turgid weight ratio and a decrease in osmotic potential at full turgor and water potential at zero turgor.

Variation in stem radial growth of the Australian conifer, Callitris columellaris, across the world’s driest and least fertile vegetated continent

“…Within the combined arid and temperate zones, rainfall effects on ring width were surprisingly weak given the fivefold range in recent average annual rainfall (134-687 mm). This observation is consistent with the fact that C. columellaris is one of the world's most drought-tolerant tree species, with xylem that is extremely resistant to cavitation and foliage capable of withstanding very low water potentials (Clayton-Greene 1983;Brodribb et al 2010).…”

Selection of species and provenances for low-rainfall areas: physiological responses of Eucalyptus cloeziana and Eucalyptus argophloia to seasonal conditions in subtropical Queensland

“…2). A similar lowering of leaf water potential reported for Eucalyptus wandoo (Colquhoun et al, 1984) and for Eucalyptus pulchella (Davidson and Reid, 1989) was associated with the ability to extract more water from the soil-a characteristic reported for eucalypts growing on drought prone sites (Doley, 1967;Ladiges, 1975;Clayton-Greene, 1983). The tendency to maintain relatively high gas exchange indicates little regulation of water loss as has been reported for E. marginata (Doley, 1967;Colquhoun et al, 1984), E. calophylla (Colquhoun et al, 1984), E. microcarpa (Attiwill and Clayton-Greene, 1984) and E. leucoxylon (Sinclair, 1980).…”

Hydraulic properties and photosynthetic rates in co-occurring lianas and trees in a seasonal tropical rainforest in southwestern China

“…In this context, we might expect that lianas suffer little from water stress during a dry season. Several morphological and physiological traits are involved in drought resistance, including rooting depth (Trifilò et al 2004), xylem vulnerability to cavitation (Choat et al 2007;Lopez et al 2005;Maherali et al 2004), and osmotic adjustment (Clayton-Greene 1983;Cao 2000). Lianas have been shown to have deep root systems (Restom and Nepstad 2004), but we know less about their xylem vulnerability to cavitation and osmotic adjustment in a dry season.…”