Similar diurnal, seasonal and annual rhythms in radial root expansion across two coexisting Mediterranean oak species

2020 ◽  
Vol 40 (7) ◽  
pp. 956-968 ◽  
Author(s):  
Josu G Alday ◽  
Jesús Julio Camarero ◽  
Jesús Revilla ◽  
Víctor Resco de Dios
Keyword(s):  
Vapor Pressure Deficit ◽  
Environmental Parameters ◽  
Late Summer ◽  
Growth Strategy ◽  
Environmental Drivers ◽  
Root Radius ◽  
Tree Roots ◽  
Quercus Faginea

Abstract Dendrometers are being increasingly used to measure stem radius changes in trees and to unravel the mechanisms underlying stem daily rhythms of radial expansion and contraction. Nevertheless, automated dendrometers have not been often used to measure root radius dynamics, their relationship with environmental variables and the influence of endogenous processes, especially in drought-prone Mediterranean areas. Here, we measured root radius dynamics of two coexisting oak species (the evergreen Quercus ilex L. and the deciduous Quercus faginea Lam). Our goals were to describe annual, seasonal and diurnal scale root radius patterns and to disentangle the role of different environmental parameters as drivers. Long-term high-resolution measurements (every 15 min over 7 years) were collected with automated point dendrometers on the main tree roots of five individuals per species. Root radius annual change patterns were bimodal and similar for both oak species. Quercus faginea Lam showed three times larger root increment in the spring than Q. ilex, but the bimodal pattern was stronger in Q. ilex, which showed a larger root increment in autumn. Quercus faginea Lam showed an earlier root phenological activation in the spring and in late summer compared with Q. ilex. The effects of environmental drivers across species were similar at daily scales: root radius increased with air temperature and soil moisture, and it decreased with rising vapor pressure deficit. Furthermore, daily root radius variations for both oak species were maintained after extracting statistically the environmental effects, which points toward a significant role of endogenous drivers. These differences in root radius change patterns at seasonal to daily scales likely result from the differences in leaf phenology and growth strategy. Quercus faginea Lam is deciduous and has a faster growing rate in spring than the evergreen Q. ilex, which can grow more in summer.

Role of Ecklonia radiata (C. Ag.) J. Agardh in determining trace metal availability in coastal waters. I. Total trace metals

1987 ◽  
Vol 38 (3) ◽  
pp. 307 ◽  
Author(s):  
HW Higgins ◽  
DJ Mackey
Keyword(s):  
Trace Metals ◽  
Metal Binding ◽  
Late Summer ◽  
Dry Weight ◽  
Metal Availability ◽  
Metal Binding Sites ◽  
Accumulation Of Metals ◽  
Concentration Factors

No seasonal variations were found in the concentrations of Zn, Cd, Cu, K, Ca, Mg and Na in the kelp E. radiata collected from the marine-dominated Port Hacking estuary on the east coast of Australia. Concentrations of Fe and Mn were about 60% higher in late summer. The relative distributions of all metals between different kelp tissues, however, showed no seasonal variation. Concentration factors (dry weight basis) for trace metals ranged from 2600 for Cu to 68 000 for Fe. With high biomasses common in macroalgal ecosystems, a large proportion of the non-sediment- bound trace metals can be associated with the macroalgae, which therefore act as substantial buffers for these elements. Metal concentration factors (Y, wet wt basis) were related to oceanic residence times (τ) by the equation log Y = -0.69 logτ + 5.4. The distribution of the aikaii and akaline earth metais (K, Ca, Mg and Na) was relativeiy uniform throughout the various kelp tissues. However, concentrations of Fe, Mn, Zn and Cd were significantly higher in the older extremities (holdfast and eroding tip) than in the meristematic region. Although the holdfast also had higher levels of Cu than the meristem, levels were lower in the eroding tip. The results suggest either a slow net intracellular accumulation of metals with time or an increase in potential metal- binding sites as the extremities senesce. Translocation and elimination of surplus metals through the eroding tip or holdfast was thought not to be important in E. radiata as metal concentrations did not differ between live and dead haptera of the holdfast. Likewise, storage of metals in either the holdfast or eroding tip was considered unlikely because of the constant relative tissue distribution throughout the year and lack of metal mobilization during periods of growth. Pretreatment of kelp tissue with an EDTA wash released about 90% of the total Zn and Cd, 25% of the Cu and 7% of the Fe, suggesting that a large proportion of the total kelp Zn and Cd is associated with the apparent free space (AFS). With rapid exchange between seawater and the AFS, E. radiata is therefore not generally useful as a sentinel accumulator species in pollution studies for assessing long term integrated changes of metals in the water column.

scholarly journals Diel, seasonal, and interannual patterns in mesozooplankton abundance in the Sargasso Sea

2018 ◽  
Vol 76 (1) ◽  
pp. 217-231 ◽  
Author(s):  
Jami A Ivory ◽  
Deborah K Steinberg ◽  
Robert J Latour
Keyword(s):  
Time Series ◽  
Linear Models ◽  
Imaging System ◽  
Environmental Parameters ◽  
Late Summer ◽  
Late Winter ◽  
Sargasso Sea ◽  
Calanoid Copepods ◽  
Decadal Scale

Abstract Temporal changes in mesozooplankton abundance affect planktonic food web interactions and biogeochemistry. We enumerated mesozooplankton from monthly day and night tows in the epipelagic zone at the Bermuda Atlantic Time-series Study (BATS) site in the Sargasso Sea (1999–2010). Abundances of each taxon were determined using a ZooScan imaging system and microscopy. Generalized linear models were used to determine environmental parameters that best explained abundance patterns. Taxa with pronounced diel vertical migration included euphausiids, amphipods, Limacina spp. pteropods, and other shelled pteropods. Taxa with a pronounced spring abundance peak included euphausiids, appendicularians, and Limacina spp., while harpacticoid copepods peaked in late summer, and calanoid copepods in late winter/early spring and summer. Many taxa increased in 2003, coincident with a diatom bloom and the largest primary production peak in the time series. Long-term, increasing trends occurred in calanoid and oncaeid copepods, and ostracods, with barnacle nauplii significantly increasing. Sub-decadal-scale climate oscillations and long-term warming may be driving decreases in shelled pteropods and appendicularians. Chaetognath abundance increased in response to increased density of a major prey taxon, calanoid copepods. Calanoid copepods and ostracods increased with increasing water column stratification index and the Atlantic Multidecadal Oscillation index, indicating warmer sea surface temperatures favour these taxa.

scholarly journals Hydrometeorology: Review of Past, Present and Future Observation Methods

2020 ◽  
Author(s):  
Mohammad Valipour ◽  
Sayed M. Bateni ◽  
Nicolas R. Dalezios ◽  
Mansour Almazroui ◽  
Essam Heggy ◽  
...  
Keyword(s):  
Numerical Models ◽  
Environmental Parameters ◽  
Weather Forecast ◽  
The Earth ◽  
Observation Methods ◽  
Modeling And Forecasting ◽  
Climate Evolution ◽  
Modern Knowledge

Hydrometeorology aims at measuring and understanding the physics, chemistry, energy and water fluxes of the atmosphere, and their coupling with the earth surface environmental parameters. Accurate hydrometeorological records and observations with different timelines are crucial to assess climate evolution and weather forecast. Historical records suggest that the first hydrometeorological observations date back to ca 3500 BC. Reviewing these observations in the light of our modern knowledge of the dynamic of atmospheres is critical as it can reduce the ambiguities associated to understanding major fluctuations or evolutions in the earth climate. Today, the ambiguities in hydrometeorological observations have significantly improved due to the advances in monitoring, modeling, and forecasting of processes related to the land-atmosphere coupling and forcing. Numerical models have been developed to forecast hydrometeorological phenomena in short-, medium- and long-term horizons, ranging from hourly to annual timescales. We provide herein a synthetic review of advances in hydrometeorological observations from their infancy to today. In particular, we discuss the role of hydrometeorological records, observations, and modeling in assessing the amplitude and time-scale for climate change and global warming.

Increased growing-season productivity drives earlier autumn leaf senescence in temperate trees

Science ◽  
2020 ◽  
Vol 370 (6520) ◽  
pp. 1066-1071 ◽  
Author(s):  
Deborah Zani ◽  
Thomas W. Crowther ◽  
Lidong Mo ◽  
Susanne S. Renner ◽  
Constantin M. Zohner
Keyword(s):  
Leaf Senescence ◽  
Critical Role ◽  
Biotic Interactions ◽  
Growing Season ◽  
Environmental Drivers ◽  
Light Levels ◽  
Temperate Trees ◽  
Autumn Leaf

Changes in the growing-season lengths of temperate trees greatly affect biotic interactions and global carbon balance. Yet future growing-season trajectories remain highly uncertain because the environmental drivers of autumn leaf senescence are poorly understood. Using experiments and long-term observations, we show that increases in spring and summer productivity due to elevated carbon dioxide, temperature, or light levels drive earlier senescence. Accounting for this effect improved the accuracy of senescence predictions by 27 to 42% and reversed future predictions from a previously expected 2- to 3-week delay over the rest of the century to an advance of 3 to 6 days. These findings demonstrate the critical role of sink limitation in governing the end of seasonal activity and reveal important constraints on future growing-season lengths and carbon uptake of trees.

scholarly journals The Effect of Ecological and Geographical Factors on Environmental Parameters as a Background for Vegetables Selection

2018 ◽  
Vol 22 (2) ◽  
pp. 99-106
Author(s):  
Uladzimir Skaryna ◽  
Vitali Skaryna
Keyword(s):  
Environmental Parameters ◽  
Parent Material ◽  
Ecological Sustainability ◽  
Selection Efficiency ◽  
Plant Selection ◽  
Statistical Parameters ◽  
Adaptive Ability ◽  
Sustainable Productivity

AbstractThe aim of the study is to find out the role of the ecological and geographical fator in obtaining sustainable yields and the assessment of the environment as a background for the selection in breeding of vegetable adaptive ability. Objects of research: winter garlic, vegetables beans, headed salad. Research was conducted in various ecological and geographical zones of Belarus, Russia, Uzbekistan. Environmental parameters as the background for selection were determined using Kilchevsky’s, L. V. Hotyleva’s (1985), technique, Kilchevsky (1985). Differences between testing points on environmental parameters for determining the trait “yielding capacity” have been revealed, maximum environmental productivity at assessing various genotype sets has been determined. Long-term research showed that sustainable productivity depends on the ability of a genotype to respond to environmental conditions. Based on the obtained results, statistical parameters of quantity traits of the parent material, their variability depending on ecological-geographical factor and the character of influence on the potential yields and ecological sustainability have been received. Using various ecological and geographical zones helps to reveal the potential of plants in given conditions on sustainability and productivity parameters. Testing of winter garlic, beans, head salad allowed differentiation of them according to adaptability capacity at various set of genotypes. It was found out that research must be carried out at highly productive and analyzing backgrounds to get the required material. One of the main methods enabling to increase plant selection efficiency is the use of natural ecological backgrounds.

Abusive head trauma (AHT) outcome at long-term follow-up and the role of elective neurosurgical approach: A report of 22 cases

2013 ◽  
Author(s):  
Francesca Menegazzo ◽  
Melissa Rosa Rizzotto ◽  
Martina Bua ◽  
Luisa Pinello ◽  
Elisabetta Tono ◽  
...  
Keyword(s):  
Head Trauma ◽  
Abusive Head Trauma ◽  
Long Term Follow Up

The Second Start of Transformation in Ukraine?

2014 ◽  
pp. 30-52 ◽  
Author(s):  
L. Grigoryev ◽  
E. Buryak ◽  
A. Golyashev
Keyword(s):  
Economic Growth ◽  
Armed Conflict ◽  
Political Crisis ◽  
Investment Climate ◽  
Institutional Reforms ◽  
Personal Consumption ◽  
Governance Quality ◽  
Political Turmoil

The Ukrainian socio-economic crisis has been developing for years and resulted in the open socio-political turmoil and armed conflict. The Ukrainian population didn’t meet objectives of the post-Soviet transformation, and people were disillusioned for years, losing trust in the state and the Future. The role of workers’ remittances in the Ukrainian economy is underestimated, since the personal consumption and stability depend strongly on them. Social inequality, oligarchic control of key national assets contributed to instability as well as regional disparity, aggravated by identity differences. Economic growth is slow due to a long-term underinvestment, and prospects of improvement are dependent on some difficult institutional reforms, macro stability, open external markets and the elites’ consensus. Recovering after socio-economic and political crisis will need not merely time, but also governance quality improvement, institutions reform, the investment climate revival - that can be attributed as the second transformation in Ukraine.

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