What Induces Central Australian Arid Zone Trees and Shrubs to Flower and Fruit?

Abstract

I vllL@l!y UL L U~I~G~V~L~U I IZommission of the Northern Territory, Alice Springs, NT 0871. AbstractWe developed two sets of regression models for flowering and fruiting of arid zone trees and shrubs, based on (i) rainfall in the current and preceding seasons and (ii) soil moisture lagged over varying time periods combined with mean maximum temperature and daylength in the month prior to phenological observations. Using up to 4 years of flowering and fruiting records, we found that both approaches identified responses matching those reported in two other long-term data sets or in the literature, for some species but not for all. The second approach appeared to provide better correlations than the first but we were unable to predict flowering and fruiting effectively.Flowering and fruiting of central Australian trees and shrubs were least in late summer, creating potential limitations on animal populations dependent on them for food. With better predictive capabilities, there is some scope for managing the trees and shrubs for particular purposes. However, very long-term phenological records are needed to improve predictions.

Climatic factors governing plant phenological phases along a Norwegian fjord

“…S. aucuparia and S. vulgaris were compared by Köppen (1927) and Fraxinus and Quercus robur by Batta (1969b). More recently the same was observed by Friedel et al (1993) in arid zones. Even various cultivars of the same species may react differently to the environment (e.g.…”

“…Such a change in the effect seemed to take place about 1 month before the time of the phase. In arid zones the effect on flowering was often lagged about 1 month by the moisture conditions (Friedel et al 1993). Cloudy, mild weather was thus an advantage for the phenology of plants in early spring, while later clear, dry weather generally accelerated flowering in the present study.…”

“…Garner and Allard (1920) and later workers (e.g. Wielgolaski 1966;Friedel et al 1993) state the importance of the day length on development in many plants. In field studies this means variation in a plant phenophase at different latitudes, all other environmental factors being the same.…”

“…In field studies this means variation in a plant phenophase at different latitudes, all other environmental factors being the same. The phenological influence of light and water supply has been discussed by Post (1942), Unger and Schneider (1956) and Friedel et al (1993), among others. It has also been stressed that periodic biological events may be influenced by the soil (e.g.…”

The reproductive phenology of three sympatric species of columnar cacti on Curaçao

“…The water retention properties of the soil, rainfall (Beatley, 1974), and temperature (Halvorson & Pattern, 1975) are all factors that may affect the phenology of plants in arid tropical regions; plants of these regions are usually dependent on irregular rainfall (Friedel et al, 1993). Whatever the environmental condition triggering a plant species to flower, a floral homologue that shares the same pollinators may benefit from being triggered to flower by an opposite mechanism.…”