scholarly journals Water: agriculture vs energy development in the Four Corners Area. [Impact of reduced water availability, due to increased energy development, on agriculture]

1979 ◽  
Author(s):  
M Gisser ◽  
R Lansford ◽  
M Evans ◽  
W Gorman ◽  
B Creel ◽  
...  
Keyword(s):  
Water Availability ◽  
Energy Development ◽  
Four Corners ◽  
Reduced Water

Changes in arthropod community but not plant quality benefit a specialist herbivore on plant under reduced water availability

2020 ◽  
Author(s):  
Po-An Lin ◽  
Chia-Ming Liu ◽  
Jia-Ang Ou ◽  
Cheng-Han Sun ◽  
Wen-Po Chuang ◽  
...  
Keyword(s):  
Water Availability ◽  
Pieris Rapae ◽  
Plant Quality ◽  
Physiological Adaptation ◽  
Insect Herbivores ◽  
Specialist Herbivore ◽  
Herbivore Community ◽  
Two Populations ◽  
Reduced Water

AbstractPlants grow under reduced water availability can have divergent effects on insect herbivores, in some instances producing benefits to them. However, the forces mediating these positive impacts remain mostly unclear. We conducted a manipulative field study using a specialist herbivore Pieris rapae, and its host plant, Rorippa indica, in two populations to identify how water availability impacts overall plant quality and multitrophic interactions. We observed that R. indica growing under low water availability led to higher survival of P. rapae larvae. The increase in survival of eggs and larvae was related to the reduced abundance of other herbivores and natural enemies. Water availability had differential impacts on members of the herbivore community through changes in plant quality. Low water availability decreased the quality of R. indica to most herbivores as indicated by reduced abundance in the field and decreased relative growth rate in feeding assays. In contrast, the performance of P. rapae larvae were not affected by differences in sympatric R. indica grown under different water availability. These results indicate that local P. rapae possess some physiological adaptation to overcome fluctuations in host quality. Our findings illustrate that reduced water availability is beneficial to a specialist herbivore, but detrimental to most other herbivores. Our work highlights the complex roles of the arthropod communities associated with plants in determining the impacts of water availability on insect herbivores.

Defining phreatophyte response to reduced water availability: preliminary investigations on the use of xylem cavitation vulnerability in Banksia woodland species

2006 ◽  
Vol 54 (2) ◽  
pp. 173 ◽  
Author(s):  
R. H. Froend ◽  
P. L. Drake
Keyword(s):  
Water Availability ◽  
Tree Mortality ◽  
Water Source ◽  
Resource Planning ◽  
Xylem Cavitation ◽  
Xylem Water Potential ◽  
Critical Thresholds ◽  
Species Response ◽  
Critical Range ◽  
Reduced Water

The consideration of phreatophyte response to changes in water availability is important in identifying ecological water requirements in water-resource planning. Although much is known about water-source partitioning and intra- and interspecific variability in groundwater use by Banksia woodland species, little is known about the response of these species to groundwater draw-down. This paper describes a preliminary study into the use of xylem cavitation vulnerability as a measure of species response to reduced water availability. A response function and critical range in percentage loss of conductance is identified for four Banksia woodland overstorey species. Similarity in the vulnerability curves of B. attenuata R.Br. and B. menziesii R.Br. at low tensions supports the notion that they occupy a similar ecohydrological niche, as defined by their broad distributions relative to depth to groundwater. B. ilicifolia R.Br., however, as an obligate phreatophyte, has a range restricted to environments of higher water availability and shallower depth to groundwater and this is reflected in greater vulnerability to cavitation (relative to other Banksia) at lower tensions. The wetland tree Melaleuca preissiana Schauer generally expressed a greater vulnerability at any given xylem water potential (Ψx). This paper identifies the range in Ψx within which there is an elevated risk of tree mortality, and represents a first step towards quantifying the critical thresholds in the response of Banksia woodland species to reduced water availability.

Photosynthesis in Wheat at the Grain Filling Stage Is Altered by Larval Wheat Stem Sawfly (Hymenoptera: Cephidae) Injury and Reduced Water Availability

2007 ◽  
Vol 42 (2) ◽  
pp. 228-238 ◽  
Author(s):  
Tulio B. Macedo ◽  
David K. Weaver ◽  
Robert K. D. Peterson
Keyword(s):  
Chlorophyll A ◽  
Water Availability ◽  
Chlorophyll A Fluorescence ◽  
Grain Filling ◽  
Larval Feeding ◽  
Primary Metabolism ◽  
Wheat Stem Sawfly ◽  
Filling Stage ◽  
Grain Filling Stage ◽  
Reduced Water

The impact of larval feeding by wheat stem sawfly, Cephus cinctus Norton (Hymenoptera: Cephidae), and reduced water availability on the photosynthesis and primary metabolism of wheat, Triticum aestivum (L.), was evaluated at the grain-filling developmental stage. Photosynthetic parameters measured included photosynthesis (Ps), stomatal conductance (gs), and transpiration (E) in the flag leaves. The parameters were measured at 4 wks after the treatments were imposed. Additional concomitant chlorophyll a fluorescence measurements were taken using both dark- and light-adapted tests. Photosynthesis was significantly affected by C. cinctus injury and suboptimal water availability. However, no significant interaction was observed between the two treatment factors. Plants under a reduced or suboptimal watering regime had Ps rates that were 43.7% lower than plants that were watered daily. We also observed a 12% higher Ps rate in uninfested plants compared to plants infested by C. cinctus. Several chlorophyll a fluorescence parameters also were affected by C. cinctus. Specifically, reductions in the photochemical efficiency of photosystem II (PSII) of C. cinctus infested plants were observed for plants under reduced water availability. This study demonstrates that wheat plants at the grain filling stage have reduced photosynthetic capacity when watered less frequently or when subjected to C. cinctus larval feeding injury. Less frequent watering and larval feeding injury did not have significant impacts on yield in this greenhouse study.

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