Eco-Physiological Studies on Plants in Arid and Semi-Arid Regions in Western Australia: V. Heat Resistance Limits of Photosynthetic Organs of Different Seasons, Their Relation to Water Deficits and Cell Sap Properties and the Regeneration Ability

1971 ◽  
Vol 59 (2) ◽  
pp. 365 ◽  
Author(s):  
Erhart O. Hellmuth
Keyword(s):  
Heat Resistance ◽  
Western Australia ◽  
Arid Regions ◽  
Regeneration Ability ◽  
Water Deficits ◽  
Different Seasons ◽  
Physiological Studies ◽  
Semi Arid

Sandalwood (Santalum spicatum) establishment in the semi-arid and arid regions of Western Australia

2013 ◽  
Vol 35 (1) ◽  
pp. 109 ◽  
Author(s):  
Benjamin Sawyer
Keyword(s):  
State Government ◽  
Western Australia ◽  
Significant Relationship ◽  
Arid Regions ◽  
Annual Rainfall ◽  
European Settlement ◽  
Soil Preparation ◽  
Santalum Spicatum ◽  
Semi Arid Region ◽  
Semi Arid

Harvesting of sandalwood (Santalum spicatum) occurs mainly from wild stands in the semi-arid and arid regions (typical annual rainfall 150–300 mm) of Western Australia. Regeneration of wild sandalwood in these regions is believed to be low since the occurrence of changes in land use associated with European settlement. This is thought to be due to factors including drought, poor seed dispersal and grazing. The objective of the study was to increase the germination and establishment of sandalwood through exploring seed response to rainfall. Additionally, the potential of soil-preparation techniques to utilise trace amounts of moisture was investigated. Two 25-ha plots were located either side of the semi-arid–arid divide. Into the plots 16 replicates of the control and 96 replicates of treatments were installed and sown with 11 200 seeds. Rainfall and other weather parameters were recorded at each site with an automated weather station. The study was replicated in 2008 and 2009. It was concluded from the study that there was a statistically significant relationship between germination and rainfall. It is proposed that the germination threshold is 264 mm per year which coincides with the long-term annual rainfall average of Kalgoorlie, Western Australia. Furthermore, a statistically significant relationship between germination and soil preparation was demonstrated. Ripping crust-forming soils before sowing and the construction of water-harvest banks had a positive effect. Information gained from these studies has led to the Western Australian State Government implementing a seeding program to increase sandalwood regeneration in the semi-arid region.

scholarly journals Progressive water deficits during multi-year droughts in central-south Chile

2020 ◽  
Author(s):  
Camila Alvarez-Garreton ◽  
Juan Pablo Boisier ◽  
René Garreaud ◽  
Jan Seibert ◽  
Marc Vis
Keyword(s):  
Water Supply ◽  
Arid Regions ◽  
Snow Accumulation ◽  
Annual Rainfall ◽  
General Question ◽  
Runoff Generation ◽  
Water Deficits ◽  
Moderate Drought ◽  
Central South ◽  
Semi Arid

Abstract. A decade-long (2010–2019) period with precipitation deficits in central-south Chile (30–41º S), the so-called megadrought (MD), has led to larger than expected hydrological response and water deficits, indicating an intensification in drought propagation. We used the CAMELS-CL dataset and simulations from the HBV hydrological model to explore the causes of such intensification. Across 124 basins with varying snow/rainfall regimes, we compared annual rainfall-runoff (R-R) relationships and runoff generation mechanisms before and during the MD, and identified those catchments where drought propagation was intensified. We show that catchments’ hydrological memory -mediated by groundwater flows- is a key control of drought propagation intensity, and that baseflow contribution to runoff is positively correlated with snow accumulation preceding the year affected by a drought. Hence, under persistent drought conditions, snow-dominated catchments progressively generate less water, compared with their historical behaviour, notably affecting the semi-arid regions in central Chile. Finally, we addressed a general question: what is worse, an extreme single year drought or a persistent moderate drought? In semi-arid regions, where water provision strongly depends on both the current and previous precipitation seasons, the worst scenario would be an extreme meteorological drought following consecutive years of precipitation below average. In temperate regions of southern Chile, where catchments have more pluvial regimes, hydrologic memory is still an important factor, but water supply is more strongly dependant on the meteorological conditions of the current year, and therefore an extreme drought would have a higher impact on water supply than a persistent but moderate drought.

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