scholarly journals The Intensity of Simulated Grazing Modifies Costs and Benefits of Physiological Integration in a Rhizomatous Clonal Plant

2020 ◽  
Vol 17 (8) ◽  
pp. 2724
Author(s):  
Jushan Liu ◽  
Chen Chen ◽  
Yao Pan ◽  
Yang Zhang ◽  
Ying Gao
Keyword(s):  
Compensatory Growth ◽  
Grazing Intensity ◽  
Clonal Plants ◽  
Physiological Integration ◽  
Leymus Chinensis ◽  
Moderate Intensity ◽  
Heterogeneous Environments ◽  
Simulated Grazing ◽  
Net Benefits ◽  
Benefits And Costs

Clonal plants in grasslands are special species with physiological integration which can enhance their ability to tolerate herbivory stress especially in heterogeneous environments. However, little is known about how grazing intensity affects the trade-off between the benefits and costs of physiological integration, and the mechanism by which physiological integration improves compensatory growth in response to herbivory stress. We examined the effects of simulated grazing intensity on compensatory growth and physiological integration in a clonal species Leymus chinensis with a greenhouse experiment. This experiment was conducted in a factorial design involving nutrient heterogeneity (high-high, high-low, low-high, low-low), simulated grazing by clipping (0%, 25%, 50% or 75% shoot removal) and rhizome connection (intact versus severed) treatments. Compensatory indexes at 25% and 50% clipping levels were higher than that at 75% clipping level except in low-low nutrient treatments. Physiological integration decreased and increased compensatory indexes when the target-ramets worked as exporter and importer, respectively. Generally, clipping increased both benefits and costs of physiological integration, but its net benefits (benefits minus costs) changed with clipping intensity. Physiological integration optimized compensatory growth at light and moderate clipping intensity, and its net benefits determined the high capacity of compensatory growth. Grassland managements such as grazing or mowing at light and moderate intensity would maximize the profit of physiological integration and improve grassland sustainability.

scholarly journals Physiological Integration Ameliorates Negative Effects of Water Stress in Salt-sensitive ‘C198’ Common Bermudagrass

2015 ◽  
Vol 140 (3) ◽  
pp. 288-294 ◽  
Author(s):  
Erick Amombo ◽  
Longxing Hu ◽  
Jibiao Fan ◽  
Zhengrong Hu ◽  
Jinmin Fu
Keyword(s):  
Antioxidant Enzymes ◽  
Antioxidant Enzyme ◽  
Resource Sharing ◽  
Cynodon Dactylon ◽  
Clonal Plants ◽  
Physiological Integration ◽  
Antioxidant Enzyme Activities ◽  
Heterogeneous Environments ◽  
Peg 6000 ◽  
Common Bermudagrass

Clonal plants can consist of connected individual ramets that enhance resource sharing through physiological integration. This integration enables the whole clone to tolerate environmental stresses. The objective of this research was to investigate the effects of physical ramet connections on the integration of antioxidant enzymes in clonal common bermudagrass (Cynodon dactylon) growing under heterogeneously distributed water; i.e., nonuniform distribution of water due to 20% polyethylene glycol (PEG 6000) treatment on some ramets and not others. The bottom, middle, upper and three fragments of clonal common bermudagrass were subjected to 20% PEG 6000 with water potential of −1.8 MPa to induce heterogeneous and homogeneous drought stress. The control was not treated with 20% PEG 6000. Within the heterogeneous treatment, water stressed clonal fragments generally had higher leaf and root antioxidant enzyme activities with respect to superoxide dismutase, catalase, peroxidase (except for root peroxidase). There was no difference in antioxidant enzyme activity within the connected clonal ramets for homogeneous treatment; i.e., three connected ramets treated with 20% PEG 6000. Osmotically stressed clonal fragments under heterogeneous environments had a lower level of malonaldehyde (MDA) compared with those in homogeneous regimes. The antioxidant enzyme integration was affected by directionality and water availability contrast. This was indicated by significant decline in MDA levels within the heterogeneous treatments as compared with homogeneous treatment, which suggested reduced lipid peroxidation. These results suggested that ramet connections facilitate integration of antioxidant enzymes within clonal plants growing in heterogeneously available water. Enzymes were integrated from clonal fragments growing in water sufficient environment to those in water stressed regimes. This enhanced reactive oxygen species scavenging capacity of the entire clone hence improved drought tolerance.

Development, photosynthetic activity and habitat selection of the clonal plant Fragaria vesca growing in copper-polluted soil

2006 ◽  
Vol 33 (10) ◽  
pp. 961 ◽  
Author(s):  
Sergio R. Roiloa ◽  
Rubén Retuerto
Keyword(s):  
Process Integration ◽  
Photochemical Efficiency ◽  
Copper Toxicity ◽  
Feedback Regulation ◽  
Clonal Plant ◽  
Clonal Plants ◽  
Physiological Integration ◽  
Total Biomass ◽  
Heterogeneous Environments ◽  
Fragaria Vesca

The ability of clonal systems to spread by ramet production may expose the clone to spatial heterogeneity. This study explored the physiological and morphological responses in the clonal plant Fragaria vesca L. growing in homogeneous (Cu-contaminated or uncontaminated) or in heterogeneous environments with patches of contrasting quality (Cu-contaminated or uncontaminated). We also investigated the potential of this species to selectively establish ramets within a heterogeneous environment. In heterogeneous environments, plants expanded ramets randomly, but selectively established ramets in the favourable patches. We discuss whether the selective establishment of ramets is a consequence of direct suppression of plant growth due to copper toxicity. The assimilate demand from offspring ramets in unfavourable environments increased the chlorophyll content and photosynthetic efficiency of parents by a feedback regulation process. Integration ameliorated the effects of copper on the photochemical efficiency of the offspring ramets. We did not observe integration costs, in terms of total biomass, for parents supporting ramets in Cu-contaminated environments, although we did detect costs in terms of ramet production. Parents with offspring ramets in Cu-contaminated environments produced 25 times more reproductive biomass than parents with offspring ramets in uncontaminated environments. We interpret this as a strategy for escaping from stressful environments. In this study, we extend the concept of physiological integration in clonal plants to include photochemical responses.

Accounting for the Distribution of Benefits and Costs in Benefit–Cost Analysis

2020 ◽  
pp. 1-21
Author(s):  
James K. Hammitt
Keyword(s):  
Cost Analysis ◽  
Decision Makers ◽  
Policy Choice ◽  
Alternative Evaluation ◽  
Benefit Cost Analysis ◽  
Transfer Programs ◽  
Net Benefits ◽  
Benefit Cost ◽  
Benefits And Costs

Abstract Benefit–cost analysis (BCA) is often viewed as measuring the efficiency of a policy independent of the distribution of its consequences. The role of distributional effects on policy choice is disputed; either: (a) the policy that maximizes net benefits should be selected and distributional concerns should be addressed through other measures, such as tax and transfer programs or (b) BCA should be supplemented with distributional analysis and decision-makers should weigh efficiency and distribution in policy choice. The separation of efficiency and distribution is misleading. The measure of efficiency depends on the numéraire chosen for the analysis, whether monetary values or some other good (unless individuals have the same rates of substitution between them). The choice of numéraire is not neutral; it can affect the ranking of policies by calculated net benefits. Alternative evaluation methods, such as BCA using a different numéraire, weighted BCA, or a social welfare function (SWF), may better integrate concerns about distribution and efficiency. The most appropriate numéraire, distributional weights, or SWFs cannot be measured or statistically estimated; it is a normative choice.

An evaluation of beef carcass quality 2. Influence of variation in grazing intensity and the level of barley supplementation with silage on the carcass and meat quality of Friesian steers

1972 ◽  
Vol 15 (3) ◽  
pp. 229-237
Author(s):  
C. E. Hinks ◽  
J. H. D. Prescott
Keyword(s):  
Meat Quality ◽  
Compensatory Growth ◽  
Live Weight ◽  
Grazing Intensity ◽  
Carcass Composition ◽  
Carcass Weight ◽  
Eating Quality ◽  
Winter Period ◽  
Carcass Quality

SUMMARYTwo experiments concerning the effects, on the carcass and meat characteristics of 18-months-old Friesian steers, of variation in grazing intensity and the level of barley feeding with silage are reported.Groups of 12 steers were grazed at different intensities over 5-month grazing periods, such that live-weight differences of 38 kg and 16 kg were recorded at housing. No compensatory growth was recorded during the subsequent winter feeding period.Whilst the grazing treatments had little effect on carcass or meat quality, higher levels of barley feeding with silage over the winter period (710 v. 410 kg/steer) had significant effects on live-weight gain, and increased carcass weight by 21 kg at slaughter. The higher yield of carcass weight was reflected in significant differences in carcass composition, joint proportions and retail cut-out value. Sixty per cent of the carcass weight difference was removed as trim fat. Differences in carcass fatness were not associated with any differences in eating quality.

Moderate clipping stimulates over-compensatory growth of Leymus chinensis under saline-alkali stress through high allocation of biomass and nitrogen to shoots

2020 ◽  
Vol 92 (1) ◽  
pp. 95-106
Author(s):  
Huimin Ma ◽  
Congcong Zheng ◽  
Yingzhi Gao ◽  
Carol C. Baskin ◽  
Hao Sun ◽  
...  
Keyword(s):  
Compensatory Growth ◽  
Leymus Chinensis ◽  
Alkali Stress

Who Gains from and who Pays for Channel Deepening?

2005 ◽  
Vol 1909 (1) ◽  
pp. 62-69 ◽  
Author(s):  
Thomas A. Grigalunas ◽  
James J. Opaluch ◽  
Young Tae Chang
Keyword(s):  
Net Present Value ◽  
Cost Savings ◽  
Economic Benefits ◽  
The State ◽  
Sensitivity Analyses ◽  
Cost Ratio ◽  
Benefit Cost Ratio ◽  
Net Benefits ◽  
Benefit Cost ◽  
Benefits And Costs

Port dredging to accommodate larger vessels can create substantial national economic benefits. However, how affected individual states fare economically with dredging is often unclear and can be an important issue. The benefits and the costs to Delaware residents of dredging—with the recent proposed deepening of the Delaware Bay and River main federal channel as a case study—are examined. Benefits include ( a) lower transportation costs that residents might receive on imported goods, ( b) profits that residents would realize if cost savings (e.g., on refinery products) were not passed forward to Delaware users, ( c) project costs that residents would bear as federal taxpayers, and ( d) benefits that residents would realize if the use of dredged sediments for planned beach renourishment created savings to the state. Sensitivity analyses are used to reflect uncertainty in outcomes. The estimated net present value to Delaware today of all future annual quantifiable benefits and costs ranges between $15,528,393 and $14,195,700 over 50 years at 5.875%. Stated another way, the quantified net benefits for Delaware imply a benefit-cost ratio between 2.07 and 1.89. Hence, for every dollar of the $7.5 million that Delaware would pay as a nonfederal cosponsor, estimated quantifiable net benefits to the state are $2.07 to $1.89. Some benefit and cost estimates are vehemently debated between interested parties, and not all benefits and costs can be quantified.

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