Effects of Intraspecific Crowding on Water Uptake, Water Storage, Apical Growth, and Reproductive Potential in the Sahuaro Cactus, Carnegiea gigantea

1986 ◽  
Vol 147 (3) ◽  
pp. 334-341 ◽  
Author(s):  
Joseph R. McAuliffe ◽  
Fredric J. Janzen
2001 ◽  
Vol 52 (2) ◽  
pp. 247 ◽  
Author(s):  
F. X. Dunin ◽  
C. J. Smith ◽  
S. J. Zegelin ◽  
R. Leuning

In a detailed study of soil water storage and transport in a sequence of 1 year wheat and 4 years of lucerne, we evaluated drainage under the crop and lucerne as well as additional soil water uptake achieved by the subsequent lucerne phase. The study was performed at Wagga Wagga on a gradational clay soil between 1993 and 1998, during which there was both drought and high amounts of drainage (>10% of annual rainfall) from the rotation. Lucerne removed an additional 125 mm from soil water storage compared with wheat (root-zone of ~1 m), leading to an estimated reduction in drainage to 30–50% of that of rotations comprising solely annual crops and/or pasture. This additional soil water uptake by lucerne was achieved through apparent root extension of 2–2.5 m beyond that of annual crops. It was effective in generating a sink for soil water retention that was about double that of annual crops in this soil. Successful establishment of lucerne at 30 plants/m2 in the first growing season of the pasture phase was a requirement for this root extension. Seasonal water use by lucerne tended to be similar to that of crops in the growing season between May and September, because plant water uptake was confined to the top 1 m of soil. Uptake of water from the subsoil was intermittent over a 2-year period following its successful winter establishment. In each of 2 annual periods, uptake below 1 m soil depth began late in the growing season and terminated in the following autumn. Above-ground dry matter production of lucerne was lower than that by crops grown in the region despite an off-season growth component that was absent under fallow conditions following cropping. This apparent lower productivity of lucerne could be traced in part to greater allocation of assimilate to roots and also to late peak growth rates at high temperatures, which incurred a penalty in terms of lower transpiration efficiency. The shortfall in herbage production by lucerne was offset with the provision of timely, high quality fodder during summer and autumn. Lucerne conferred indirect benefits through nitrogen supply and weed control. Benefits and penalties to the agronomy and hydrology of phase farming systems with lucerne are discussed.


2020 ◽  
Author(s):  
Kathrin Kuehnhammer ◽  
Joost van Haren ◽  
Angelika Kuebert ◽  
Maren Dubbert ◽  
Nemiah Ladd ◽  
...  

<p><em>Online</em> (or: <em>in situ</em>) methods for measuring soil and plant water isotopes have been identified as an innovative and crucial step to address recently identified issues in studying water uptake using stable isotope techniques.</p><p>During a controlled three month drought and rewetting experiment at the Biosphere 2 (B2) enclosed rainforest, a recently developed online method for measuring stem water isotopes (<em>Marshall et al., 2019</em>), namely ‘stem borehole equilibration’, was combined with <em>online</em> monitoring of soil water isotopes and transpired water isotopes as well as sap flow and stem water storage. This enabled us to study root water uptake depths of different tree species and dynamic changes during the dry down and rewetting. After two months of drought, the system was supplied with isotopically labelled water (deuterated water) from down below via a pipe system spanning across the complete B2 rainforest in order to identify deep water uptake of the rainforest trees and hydraulic redistribution.</p><p>Results show that – as expected – all monitored trees responded to the drought by changing their root water uptake towards deeper soil depths while sap flow rates of most trees decreased. When rewetting the system, deep water uptake from the base of B2 (between 2.5m and 4m soil depth) was identified in all large, mature trees (Clitoria faichildiana, Hibiscus tilliaceus, Hura crepitans, Pachira aquatica). No deep water uptake was found in the smaller trees (mainly Pachira aquatica). Furthermore, stem water storage was notably different between species and affected their adaptation to drought and response to rewetting. The labelled water was also identified in the transpired water more than one month after re-starting rainfall at B2.  However, no hydraulic redistribution was identified.</p><p>The holistic approach for monitoring the interactions of soils and plants provides inevitable insights into the adaptation of (enclosed) rainforests under drought and might have implications for natural rainforests. In particular, the capability of large trees to develop deep roots and the role of stem water storage are important elements for adaptation to climatic changes and need to be studied further under ‘real’ conditions.</p><p><strong>References</strong></p><p>Marshall, J.D., Cuntz, M., Beyer, M., Dubbert, M., Kühnhammer, K., 2019. Borehole equilibration: testing a new method to monitor the isotopic composition of tree xylem water in situ. Front. Plant Sci.</p>


2009 ◽  
Vol 00 (00) ◽  
pp. 090904073309027-8
Author(s):  
H.W. Wang ◽  
S. Kyriacos ◽  
L. Cartilier

Author(s):  
Emilda Emilda

The limitations of waste management in the Cipayung Landfill (TPA) causing a buildup of garbage up to more than 30 meters. This condition has a health impact on people in Cipayung Village. This study aims to analyze the impact of waste management at Cipayung Landfill on public health in Cipayung Village, Depok City. The research is descriptive qualitative. Data obtained by purposive sampling. Data was collected by interviews, observation and documentation. Based on interviews with 30 respondents, it was found that the most common diseases were diarrhea, then other types of stomach ailments, subsequent itching on the skin and coughing. This is presumably because the environmental conditions in the form of unhealthy air and water and clean and healthy living behaviors (PHBS) have not become the habit of the people. The results indicated that there were no respondents who had implemented all of these criteria. In general respondents have implemented  3 criteria, namely maintaining hair hygiene, maintaining skin cleanliness, and maintaining hand hygiene. While maintaining clean water storage is the most often overlooked behavior. To minimize this health impact, improvements in waste management in Cipayung landfill are needed along with continuous socialization and education to develop PHBS habits and the importance of maintaining a clean environment.


2019 ◽  
Vol 3 (1) ◽  
pp. 1-14
Author(s):  
Philip Brick ◽  
Kent Woodruff

This case explores the Methow Beaver Project (MBP), an ambitious experiment to restore beaver (Castor canadensis) to a high mountain watershed in Washington State, USA. The Pacific Northwest is already experiencing weather regimes consistent with longer term climate projections, which predict longer and drier summers and stronger and wetter winter storms. Ironically, this combination makes imperative more water storage in one of the most heavily dammed regions in the nation. Although the positive role that beaver can play in watershed enhancement has been well known for decades, no project has previously attempted to re-introduce beaver on a watershed scale with a rigorous monitoring protocol designed to document improved water storage and temperature conditions needed for human uses and aquatic species. While the MBP has demonstrated that beaver can be re-introduced on a watershed scale, it has been much more difficult to scientifically demonstrate positive changes in water retention and stream temperature, given hydrologic complexity, unprecedented fire and floods, and the fact that beaver are highly mobile. This case study can help environmental studies students and natural resource policy professionals think about the broader challenges of diffuse, ecosystem services approaches to climate adaptation. Beaver-produced watershed improvements will remain difficult to quantify and verify, and thus will likely remain less attractive to water planners than conventional storage dams. But as climate conditions put additional pressure on such infrastructure, it is worth considering how beaver might be employed to augment watershed storage capacity, even if this capacity is likely to remain at least in part inscrutable.


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