Effects of herbivore-induced nutrient stress on correlates of fitness and on nutrient resorption in scrub oak (Quercusilicifolia)

1995 ◽  
Vol 25 (11) ◽  
pp. 1858-1864 ◽  
Author(s):  
Jeffrey D. May ◽  
Keith T. Killingbeck
Keyword(s):  
Nutrient Dynamics ◽  
Plant Fitness ◽  
Nitrogen And Phosphorus ◽  
Acorn Production ◽  
Nutrient Pools ◽  
Scrub Oak ◽  
Copper And Zinc ◽  
Copper Manganese ◽  
Foliar Nutrient ◽  
Nitrogen Phosphorus

We investigated effects of defoliation by gypsy moth (Lymantriadispar L.) larvae on plant fitness and on foliar nutrient dynamics in scrub oak (Quercusilicifolia Wangenh.). Complete defoliation of treatment plants in 1986 and 1987 resulted in the production of a second flush of leaves (secondary leaves) in each of those years. Insecticide effectively protected controls from herbivory. Mean radial stem growth in 1987–1988 and acorn production in 1988–1989 in plants defoliated by L. dispar were 49% and 88% less than in controls, respectively. Defoliation had little effect on the content of nitrogen, phosphorus, copper, manganese, and zinc in green leaves. However, there was significantly less nitrogen, copper, and zinc in senesced secondary leaves of treatment plants than in the primary leaves of controls. Reduced levels of copper and zinc were also evident in senesced primary leaves of defoliated plants in 1988, when no defoliation occurred. Resorption efficiencies for copper and zinc averaged, respectively, 29% and 117% higher in defoliated plants than in controls for all three years, supporting the hypothesis that resorption may be plastic in response to changes in the magnitude of internal nutrient pools. The lack of such a response in resorption of nitrogen and phosphorus may have been due to biochemical and (or) physiological limitations that prevented increased resorption, since resorption efficiencies of these elements were already high (72% and 75%, respectively).

scholarly journals Element budgets in an Arctic mesocosm CO<sub>2</sub> perturbation study

2012 ◽  
Vol 9 (8) ◽  
pp. 11885-11924 ◽  
Author(s):  
J. Czerny ◽  
K. G. Schulz ◽  
T. Boxhammer ◽  
R. G. J. Bellerby ◽  
J. Büdenbender ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Ocean Acidification ◽  
Nutrient Dynamics ◽  
Temporal Dynamics ◽  
Nitrogen And Phosphorus ◽  
Nutrient Pools ◽  
Dissolved Organics ◽  
Elemental Stoichiometry ◽  
Element Budgets ◽  
Wall Growth

Abstract. Recent studies on the impacts of ocean acidification on pelagic communities have identified changes in carbon to nutrient dynamics with related shifts in elemental stoichiometry. In principle, mesocosm experiments provide the opportunity of determining the temporal dynamics of all relevant carbon and nutrient pools and, thus, calculating elemental budgets. In practice, attempts to budget mesocosm enclosures are often hampered by uncertainties in some of the measured pools and fluxes, in particular due to uncertainties in constraining air/sea gas exchange, particle sinking, and wall growth. In an Arctic mesocosm study on ocean acidification using KOSMOS (Kiel Off-Shore Mesocosms for future Ocean Simulation) all relevant element pools and fluxes of carbon, nitrogen and phosphorus were measured, using an improved experimental design intended to narrow down some of the mentioned uncertainties. Water column concentrations of particulate and dissolved organic and inorganic constituents were determined daily. New approaches for quantitative estimates of material sinking to the bottom of the mesocosms and gas exchange in 48 h temporal resolution, as well as estimates of wall growth were developed to close the gaps in element budgets. Future elevated pCO2 was found to enhance net autotrophic community carbon uptake in 2 of the 3 experimental phases but did not significantly affect particle elemental composition. Enhanced carbon consumption appears to result in accumulation of dissolved organic compounds under nutrient recycling summer conditions. This carbon over-consumption effect becomes evident from budget calculations, but was too small to be resolved by direct measurements of dissolved organics. The out-competing of large diatoms by comparatively small algae in nutrient uptake caused reduced production rates under future ocean CO2 conditions in the end of the experiment. This CO2 induced shift away from diatoms towards smaller phytoplankton and enhanced cycling of dissolved organics was pushing the system towards a retention type food chain with overall negative effects on export potential.

Effects of Preventing Nutrient Resorption on Plant Fitness and Foliar Nutrient Dynamics

Ecology ◽  
1992 ◽  
Vol 73 (5) ◽  
pp. 1868-1878 ◽  
Author(s):  
Jeffrey D. May ◽  
Keith T. Killingbeck
Keyword(s):  
Nutrient Dynamics ◽  
Nutrient Resorption ◽  
Plant Fitness ◽  
Foliar Nutrient

scholarly journals The SN2 reaction and its relationship with the Walden inversion, the Finkelstein and Menshutkin reactions together with theoretical calculations for the Finkelstein reaction

2021 ◽  
Author(s):  
Ibon Alkorta ◽  
José Elguero
Keyword(s):  
Linear Models ◽  
Theoretical Calculations ◽  
Computational Method ◽  
Basis Set ◽  
Free Energies ◽  
Nitrogen And Phosphorus ◽  
Atom Pairs ◽  
Leaving Groups ◽  
First Time ◽  
Nitrogen Phosphorus

AbstractThis communication gives an overview of the relationships between four reactions that although related were not always perceived as such: SN2, Walden, Finkelstein, and Menshutkin. Binary interactions (SN2 & Walden, SN2 & Menshutkin, SN2 & Finkelstein, Walden & Menshutkin, Walden & Finkelstein, Menshutkin & Finkelstein) were reported. Carbon, silicon, nitrogen, and phosphorus as central atoms and fluorides, chlorides, bromides, and iodides as lateral atoms were considered. Theoretical calculations provide Gibbs free energies that were analyzed with linear models to obtain the halide contributions. The M06-2x DFT computational method and the 6-311++G(d,p) basis set have been used for all atoms except for iodine where the effective core potential def2-TZVP basis set was used. Concerning the central atom pairs, carbon/silicon vs. nitrogen/phosphorus, we reported here for the first time that the effect of valence expansion was known for Si but not for P. Concerning the lateral halogen atoms, some empirical models including the interaction between F and I as entering and leaving groups explain the Gibbs free energies.

Water-Fertilizer Coupling Effects and Efficient Utilization under Peanut-Millet Interplanting Conditions

2013 ◽  
Vol 742 ◽  
pp. 272-277
Author(s):  
Liang Shan Feng ◽  
Zhan Xiang Sun ◽  
Jia Ming Zheng
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Soil Moisture Content ◽  
Coupling Effect ◽  
Field Capacity ◽  
Nitrogen And Phosphorus ◽  
Application Rates ◽  
Optimal Value ◽  
Factor Interactions ◽  
Nitrogen Phosphorus

In this study, the results showed that water is the most important factor to affect crop yields and optimum soil moisture is lower under the conditions of peanut-and-millet interplanting. Thus, peanut-and-millet interplanting is generally able to fit most of the semi-arid region. In the interaction of various factors, the coupling effect of water and phosphorus was stronger than the coupling effect of fertilizers, following by the coupling effect of water and nitrogen. Among peanuts factors of water, nitrogen, and multi-factorial interaction of water, nitrogen, and phosphorus, water and nitrogen showed a negative effect, whereas the two-factor interactions had a positive effect. There were some differences between peanut and millet in the need for water and fertilizer, in which peanut required more nitrogen and millet needed slightly higher soil moisture and phosphorus. When other factors were in rich level, both of the optimal value for single factors of water, nitrogen, and phosphorus and the optimal value for two-factor interactions of water-nitrogen, water-phosphorus, and nitrogen-phosphorus, were higher than the optimal value for the interaction of water, nitrogen, and phosphorus. The tiny demand difference on moisture in peanut-millet interplanting could be compromised by configuring a reasonable interplanting population structure and the corresponding demand difference on fertilizer could be resolved by uneven crop planting strips. Under the condition of water-nitrogen-phosphorus interaction, the soil moisture content optimal for peanut accounted for 57.3% of the field capacity, and the related appropriate application rates of nitrogen and phosphorus were 0.98 g/pot (81.18 kg/hm2) and 0.39g/pot (32.18 kg/hm2), respectively. Likewise, the soil moisture content optimal for millet was 59.1% of the field capacity, and the counterpart appropriate application rates of nitrogen and phosphorus were 0.57 g/pot (47.03 kg/hm2) and 0.45g / pot (37.13 kg/hm2), respectively.

scholarly journals Integrating Stand and Soil Properties to Understand Foliar Nutrient Dynamics during Forest Succession Following Slash-and-Burn Agriculture in the Bolivian Amazon

PLoS ONE ◽  
2014 ◽  
Vol 9 (2) ◽  
pp. e86042 ◽  
Author(s):  
Eben N. Broadbent ◽  
Angélica M. Almeyda Zambrano ◽  
Gregory P. Asner ◽  
Marlene Soriano ◽  
Christopher B. Field ◽  
...  
Keyword(s):  
Soil Properties ◽  
Nutrient Dynamics ◽  
Forest Succession ◽  
Slash And Burn ◽  
Slash And Burn Agriculture ◽  
Bolivian Amazon ◽  
Foliar Nutrient

Nitrogen and Phosphorus Availability and the Role of Fire in Heathlands at Wilsons Promontory

1994 ◽  
Vol 42 (3) ◽  
pp. 269 ◽  
Author(s):  
MA Adams ◽  
J Iser ◽  
AD Keleher ◽  
DC Cheal
Keyword(s):  
Phosphatase Activity ◽  
C:N Ratio ◽  
Soil Nutrient ◽  
Fire Frequency ◽  
P Availability ◽  
Native Plant ◽  
Nitrogen And Phosphorus ◽  
Nutrient Pools ◽  
Inorganic P ◽  
Eucalypt Forests

Analyses of carbon, nitrogen and phosphorus in heathland soils at Wilsons Promontory and on Snake Island show that the effects of fire, including repeated fires, are confined to the surface 2 cm. The uppermost soil in long-unburnt heathlands is rich in these elements and usually has a smaller C:N ratio compared with the soil below. Indices of N and P availability (C:N ratios, concentrations of potentially mineralisable N and extractable inorganic P, phosphatase activity) are similar to those in highly productive eucalypt forests-a finding in conflict with past assessments of nutrient availability in heathlands. Phosphatase activity and concentrations of carbon, nitrogen and potentially mineralisable N were less in soils from repeatedly burnt heathlands than in soils from long unburnt heathlands whereas there was a greater concentration of extractable inorganic P in soils from repeatedly burnt heathlands. The balance between nitrogen input and loss is dependent on fire frequency and present-day management of heathland (and other native plant communities with low nutrient capitals) should recognise that over- or under-use of fire will significantly alter soil nutrient pools and availability and that these changes may alter community species composition and productivity.

Distribution of Biomass, Nitrogen, Phosphorus and Other Nutrients in Banksia marginata and B. ornata Shoots of Different Ages After Fire.

1986 ◽  
Vol 34 (6) ◽  
pp. 709 ◽  
Author(s):  
RH Groves ◽  
PJ Hocking ◽  
A Mcmahon
Keyword(s):  
National Park ◽  
Dry Matter ◽  
Lateral Roots ◽  
South Australia ◽  
Distribution Patterns ◽  
Nutrient Accumulation ◽  
Nitrogen And Phosphorus ◽  
Vegetative Organs ◽  
Western Victoria ◽  
Nitrogen Phosphorus

The heathland form of Banksia marginata Cav. regenerates rarely from seed but commonly by resprout- ing from buds on lateral roots, whereas Banksia ornata F. Muell. regenerates only from seed, usually released after fire. The two species co-occur in heath vegetation on nutrient-poor soils in south-eastern South Australia and western Victoria. Shoots were sampled from stands of B. marginata aged from 1 to 25 years and of B. ornata aged from 1 to 50+ years after fire in the Little Desert National Park, western Victoria. B. marginata, the resprouter, distributed a greater proportion of the total shoot dry matter and content of all nutrients to vegetative growth over its shorter life span than B. ornata, the non-sprouter. About 50% of the total phosphorus in B. ornata shoots at 50+ years was present in cones (including seeds) compared with only about 20% in B. marginata shoots at a comparable stage of senescence (25 years). This difference between the species was also true to a lesser degree for nitrogen. There were considerable differences between other nutrients in their distribution patterns in shoots. Nutrients could be grouped together on the basis of distribution in shoots more satisfactorily than on presumed physio- logical roles. Stems were major sites of nutrient accumulation in both species. The content of a particular nutrient in seeds as a proportion of the content in the living parts of the shoot ranged from 0.03% (Na, Mn) to 2.0% (P) in B. marginata, and from 0.3% (Na) to as high as 31% (P) in B. ornata. Concen- trations of all nutrients except sodium were much higher in seeds than in the woody cones or vegetative organs of both species; seeds of B. ornata were particularly rich in calcium and manganese. We conclude that the different patterns of distribution of biomass and nutrients, especially nitrogen and phosphorus, within shoots of the two species reflect their different regenerative modes after fire. Introduction Phosphorus and, to a lesser extent, nitrogen limit the growth of sclerophyllous shrubs on nutrient-poor soils in southern Australia

Frost hardiness and winter photosynthesis of Thujapiicata and Pseudotsugamenzlesll seedlings grown at three rates of nitrogen and phosphorus supply

1995 ◽  
Vol 25 (1) ◽  
pp. 18-28 ◽  
Author(s):  
B.J. Hawkins ◽  
M. Davradou ◽  
D. Pier ◽  
R. Shortt
Keyword(s):  
Net Photosynthesis ◽  
Douglas Fir ◽  
Frost Hardiness ◽  
Nutrient Concentrations ◽  
Nitrogen And Phosphorus ◽  
Red Cedar ◽  
Air Temperatures ◽  
Foliar Nutrient ◽  
One Year ◽  
P Supply

One-year-old seedlings of western red cedar (Thujapiicata Donn ex D.Don) and Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) were grown for one season in five nutrient treatments with nitrogen (N) supplied in solution at rates of 20, 100, or 250 mg•L−1 and phosphorus (P) supplied at rates of 4, 20, or 60 mg•L−1. Growth, onset of dormancy, frost hardiness on six dates, and foliar nutrient concentrations in autumn and spring were measured. Midwinter rates of net photosynthesis and transpiration were measured at air temperatures of 4, 7, and 11 °C in seedlings from all nutrient treatments. Recovery of net photosynthesis and transpiration in whole seedlings from the three N treatments was assessed at intervals for 28 days after the seedlings were frozen to −5, −15, and −25°C. Foliar N content differed significantly among nutrient treatments and was positively correlated with supply. Mitotic activity ceased earliest in plants with low N supply. Douglas-fir seedlings in the low-N treatment also ceased height growth earliest. These differences in growth had no significant correlation with frost hardiness. No consistent differences in frost hardiness among nutrient treatments were observed. Higher rates of N and P supply resulted in higher rates of winter net photosynthesis. Net photosynthesis was reduced dramatically by night frost, with greater damage occurring at lower temperatures. Net photosynthesis recovery occurred most quickly in seedlings with the midrate of N and P supply.

scholarly journals Effect of Intercropping and Fertility Levels on the Nitrogen, Phosphorus and Potash Content and Uptake by Summer Pearlmillet (Pennisetum glaucum L.) under South Gujarat Condition

2021 ◽  
Vol 9 (3) ◽  
pp. 174-179
Author(s):  
K. R. Patel ◽  
Keyword(s):  
Pearl Millet ◽  
Phosphorus Content ◽  
Pennisetum Glaucum ◽  
P Uptake ◽  
Green Gram ◽  
Treatment Combination ◽  
K Uptake ◽  
Nitrogen And Phosphorus ◽  
College Of Agriculture ◽  
Nitrogen Phosphorus

A field experiment was conducted at College Agronomy Farm, N. M. College of Agriculture, Navsari Agricultural University, Navsari during summer, 2019 and 2020 comprising four intercropping treatments i.e. pearlmillet sole, pearlmillet+greengram, pearlmillet+cowpea, pearlmillet+clusterbean and three fertility levels viz., 75 % RDF, 100 % RDF and 125 % RDF. Among the different intercropping system examined, sole pearl millet (I1) accumulated significantly less content of N and P in pearl millet grain and straw as compared to intercropping with pulses treatments. Pearl millet + green gram (I2) recorded significantly higher N and P uptake by pearl millet straw than other intercropping systems. The sole pearl millet (I1) was at par with pearl millet intercropped with green gram (I2) had significantly higher K content and uptake in pearl millet grain and straw. In case of fertility levels, nitrogen and phosphorus content and uptake in pearl millet grain and straw were recorded significantly higher by application of 100 % RDF. Significantly higher N, P and K uptake by pearl millet grain and straw in pooled results were produced by treatment combination of pearl millet + green gram (I2) intercropping along with 75 % RDF (F1).

scholarly journals Laboratory study on the effects of nutrient enrichment on a phytoplankton population in Sawa Lake, Iraq

2008 ◽  
Vol 5 (2) ◽  
pp. 230-236 ◽  
Author(s):  
Baghdad Science Journal
Keyword(s):  
Population Dynamics ◽  
Lake Water ◽  
Nutrient Enrichment ◽  
Cell Number ◽  
Shannon Index ◽  
Nitrogen And Phosphorus ◽  
Phytoplankton Population ◽  
Phytoplankton Cell ◽  
Nitrogen Phosphorus ◽  
Index Of Diversity

Nutrient enrichment of Sawa lake water was made using different nitrogen and phosphorus concentrations during autumn and spring at three stations. Different concentrations of nitrogen, phosphorus and N: P ratios were used to test variations in phytoplankton population dynamics. Nitrogen at a concentration of 25 µmole.l-1 and N: P ratio of 10:1 gave highest phytoplankton cell number at all stations and seasons. A total of 64 algal taxa dominated by Bacillariophyceae followed by Cyanophyceae and Chlorophyceae were identified. The values of Shannon index of diversity were more than one in the studied stations.

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