Influence of weed cover on leaf-level CO2 and H2O fluxes in an olive grove

Author(s):  
Sergio Aranda-Barranco ◽  
Andrew S Kowalski ◽  
Penélope Serrano-Ortiz ◽  
Enrique P Sánchez-Cañete

<p>The management of olive groves has a direct impact on the environment in the Mediterranean region since it is one of the most representative crops in this area. In order to prevent erosion and improve the physical-chemical conditions of the soil in these crops, the maintenance of weed cover in the alleys is an increasingly common practice. It increases the organic carbon content in the soil, improves biodiversity indices and enhances various ecosystem services such as pollination and infiltration. Now, the role of vegetation cover in olive groves on biogeochemical cycles is being studied. Although previous studies have quantified the combined effect of weed cover and olive trees on carbon and water at ecosystem level, the role of this conservation practice at the leaf level has not yet been explored.</p><p>The aim of this study is to quantify the effect of weed cover on the net CO<sub>2</sub> assimilation (A<sub>n</sub>) and transpiration (T) rates in an irrigated olive grove. To do this, two plots of olive trees with irrigation (Olea europea L. "Arbequina") in southeast Spain were sampled. In the weed-cover one (WC), spontaneous vegetation is maintained until it is mechanically mowed and left in place. In the weed-free (WF) a glyphosate-based herbicide is applied. The data were taken with a portable gas analyzer (LI-6800, Li-Cor) controlling the following environmental variables on olive leaves: atmospheric CO<sub>2</sub>, relative humidity, photosynthetic active radiation and temperature. One campaign per month was carried out (from January-2018 to January-2019) where 10 random trees were analysed in each treatment. In addition, an eddy covariance tower provided CO<sub>2</sub> and H<sub>2</sub>O fluxes at ecosystem level and they were compared with the fluxes obtained from leaf-level campaigns.</p><p>The results shown significant differences for T only in the period after mowing with T<sub>wc</sub>= 2.0 ± 0.7 mmol H<sub>2</sub>O m<sup>-2</sup>s<sup>-1</sup> vs T<sub>wf </sub>= 2.5 ± 1.0 mmol H<sub>2</sub>O m<sup>-2</sup>s<sup>-1</sup>. However, in this period ET is equal in both treatments, which suggests that the alleys with mowed weed has more ET than bare soil in the other treatment. On the other hand, there are significant differences for A<sub>net</sub> only in the period before mowing with A<sub>net-wc</sub> = 5.5 ± 3.1 μmol CO<sub>2</sub> m<sup>-2</sup>s<sup>-1</sup> vs A<sub>net-wf</sub> = 8.0 ± 3.6 μmol CO<sub>2</sub> m<sup>-2</sup>s<sup>-1</sup>. When the weeds are mowed, A<sub>net</sub> is matched in both treatments. However, higher values of NEE<sub>wc</sub> than NEE<sub>wf  </sub>are observed in the period before mowing. This suggest that the weed-cover olive groves at ecosystem level take up more carbon when the weed-cover is established although the leaves of olive trees are capturing less CO<sub>2</sub>.</p>

Rural History ◽  
2012 ◽  
Vol 23 (2) ◽  
pp. 161-184 ◽  
Author(s):  
JUAN INFANTE-AMATE

AbstractThis article argues that the landscape dominated by olive groves that is now seen as characteristic of southern Spain is a relatively recent phenomenon. In the eighteenth, nineteenth and much of the twentieth century, olives were not an industrial crop, grown on a large scale for the production of oil. Instead, olive trees were largely grown by small peasant farmers and used to produce timber and fodder as well as foodstuffs, forming one component of a diverse peasant economy. This article will analyse the changing role of the olive within the landscape of the Spanish Mediterranean, and explore the process by which production moved towards single crop cultivation by large industrial enterprises.


2021 ◽  
Vol 14 (1) ◽  
pp. 391
Author(s):  
Yiannis G. Zevgolis ◽  
Efstratios Kamatsos ◽  
Triantaphyllos Akriotis ◽  
Panayiotis G. Dimitrakopoulos ◽  
Andreas Y. Troumbis

Conservation of traditional olive groves through effective monitoring of their health state is crucial both at a tree and at a population level. In this study, we introduce a comprehensive methodological framework for estimating the traditional olive grove health state, by considering the fundamental phenotypic, spectral, and thermal traits of the olive trees. We obtained phenotypic information from olive trees on the Greek island of Lesvos by combining this with in situ measurement of spectral reflectance and thermal indices to investigate the effect of the olive tree traits on productivity, the presence of the olive leaf spot disease (OLS), and olive tree classification based on their health state. In this context, we identified a suite of important features, derived from linear and logistic regression models, which can explain productivity and accurately evaluate infected and noninfected trees. The results indicated that either specific traits or combinations of them are statistically significant predictors of productivity, while the occurrence of OLS symptoms can be identified by both the olives’ vitality traits and by the thermal variables. Finally, the classification of olive trees into different health states possibly offers significant information to explain traditional olive grove dynamics for their sustainable management.


2019 ◽  
Vol 11 (3) ◽  
pp. 221 ◽  
Author(s):  
Beatriz Rey ◽  
Nuria Aleixos ◽  
Sergio Cubero ◽  
José Blasco

The use of remote sensing to map the distribution of plant diseases has evolved considerably over the last three decades and can be performed at different scales, depending on the area to be monitored, as well as the spatial and spectral resolution required. This work describes the development of a small low-cost field robot (Remotely Operated Vehicle for Infection Monitoring in orchards, XF-ROVIM), which is intended to be a flexible solution for early detection of Xylella fastidiosa (X. fastidiosa) in olive groves at plant to leaf level. The robot is remotely driven and fitted with different sensing equipment to capture thermal, spectral and structural information about the plants. Taking into account the height of the olive trees inspected, the design includes a platform that can raise the cameras to adapt the height of the sensors to a maximum of 200 cm. The robot was tested in an olive grove (4 ha) potentially infected by X. fastidiosa in the region of Apulia, southern Italy. The tests were focused on investigating the reliability of the mechanical and electronic solutions developed as well as the capability of the sensors to obtain accurate data. The four sides of all trees in the crop were inspected by travelling along the rows in both directions, showing that it could be easily adaptable to other crops. XF-ROVIM was capable of inspecting the whole field continuously, capturing geolocated spectral information and the structure of the trees for later comparison with the in situ observations.


2021 ◽  
Vol 10 (1) ◽  
pp. 15
Author(s):  
Kostas Blekos ◽  
Anastasios Tsakas ◽  
Christos Xouris ◽  
Ioannis Evdokidis ◽  
Dimitris Alexandropoulos ◽  
...  

The intensification and expansion in the cultivation of olives have contributed to the significant spread of Verticillium wilt, which is the most important fungal problem affecting olive trees. Recent studies confirm that practices such as the use of innovative natural minerals (Zeoshell ZF1) and the application of beneficial microorganisms (Micosat F BS WP) restore health in infected trees. However, for their efficient implementation the above methodologies require the marking of trees in the early stages of infestation—a task that is impractical with traditional means (manual labor) but also very difficult, as early stages are difficult to perceive with the naked eye. In this paper, we present the results of the My Olive Grove Coach (MyOGC) project, which used multispectral imaging from unmanned aerial vehicles to develop an olive grove monitoring system based on the autonomous and automatic processing of the multispectral images using computer vision and machine learning techniques. The goal of the system is to monitor and assess the health of olive groves, help in the prediction of Verticillium wilt spread and implement a decision support system that guides the farmer/agronomist.


1995 ◽  
Vol 74 (05) ◽  
pp. 1271-1275 ◽  
Author(s):  
C M A Henkens ◽  
V J J Bom ◽  
W van der Schaaf ◽  
P M Pelsma ◽  
C Th Smit Sibinga ◽  
...  

SummaryWe measured total and free protein S (PS), protein C (PC) and factor X (FX) in 393 healthy blood donors to assess differences in relation to sex, hormonal state and age. All measured proteins were lower in women as compared to men, as were levels in premenopausal women as compared to postmenopausal women. Multiple regression analysis showed that both age and subgroup (men, pre- and postmenopausal women) were of significance for the levels of total and free PS and PC, the subgroup effect being caused by the differences between the premenopausal women and the other groups. This indicates a role of sex-hormones, most likely estrogens, in the regulation of levels of pro- and anticoagulant factors under physiologic conditions. These differences should be taken into account in daily clinical practice and may necessitate different normal ranges for men, pre- and postmenopausal women.


1998 ◽  
pp. 61-62
Author(s):  
N. S. Jurtueva

In the XIV century. centripetal tendencies began to appear in the Moscow principality. Inside the Russian church, several areas were distinguished. Part of the clergy supported the specificobar form. The other understood the need for transformations in society. As a result, this led to a split in the Russian church in the 15th century for "non-possessors" and "Josephites". The former linked the fate of the future with the ideology of hesychasm and its moral transformation, while the latter sought support in alliance with a strong secular power.


2014 ◽  
Vol 4 (2) ◽  
Author(s):  
Tamara Feldman

This paper is a contribution to the growing literature on the role of projective identification in understanding couples' dynamics. Projective identification as a defence is well suited to couples, as intimate partners provide an ideal location to deposit unwanted parts of the self. This paper illustrates how projective identification functions differently depending on the psychological health of the couple. It elucidates how healthier couples use projective identification more as a form of communication, whereas disturbed couples are inclined to employ it to invade and control the other, as captured by Meltzer's concept of "intrusive identification". These different uses of projective identification affect couples' capacities to provide what Bion called "containment". In disturbed couples, partners serve as what Meltzer termed "claustrums" whereby projections are not contained, but imprisoned or entombed in the other. Applying the concept of claustrum helps illuminate common feelings these couples express, such as feeling suffocated, stifled, trapped, held hostage, or feeling as if the relationship is killing them. Finally, this paper presents treatment challenges in working with more disturbed couples.


Moreana ◽  
2017 ◽  
Vol 54 (Number 207) (1) ◽  
pp. 36-56
Author(s):  
Gerard Wegemer

After establishing a context of More's lifelong engagement with the “calculus” of pleasure, this essay shows how the section devoted to the Utopians' pleasure philosophy is structured around five formulations of a “rule” to calculate “true and honest [honesta]” pleasure in ways that playfully imitate and echo the “rule” Cicero formulates several times in De officiis to discern one's duty when there seems to be a conflict between honestas et utilitas. When followed, the Utopian pleasure calculus shows the necessary role of societas, officii, iustitia, caritas, and the other aspects of human nature, most importantly friendship, that Cicero stresses in his rule and that he argued Epicurus ignored. Much of the irony and humor of this section depends on seeing the predominance of Ciceronian vocabulary in Raphael's unusual defense [patrocinium] of pleasure, rather than a Ciceronian defense of duty rooted in honestas. Throughout, however, this essay also shows how More goes beyond Cicero by including Augustinian and biblical allusions to suggest ways that our final end is not as Epicurus or the Stoics or Cicero claim; the language and allusions of this section point to a level of good cheer and care for neighbors and for God in ways quite different from any classical thinker.


1973 ◽  
Vol 74 (4) ◽  
pp. 769-774 ◽  
Author(s):  
Akira Yokoyama ◽  
Hiroshi Tomogane ◽  
Katuaki Ôta
Keyword(s):  

ABSTRACT A non-steroidal oestrogen antagonist, MER-25, was administered to cycling rats for elucidating the role of oestrogen in the surge of prolactin observed on the afternoon of pro-oestrus (POe). In animals injected with 20 mg of MER-25 intramuscularly on the afternoon (16.30 h) of the first day of dioestrus (D-1), the surge of prolactin was blocked while the level of prolactin on the afternoon of POe of these animals was significantly higher than that of the corresponding controls injected with oil. Ovulation was also blocked in these animals treated with the drug on the afternoon of D-l. On the other hand, treatment on the morning (10.30 h) of the 2nd day of dioestrus failed to prevent not only the surge of prolactin but also ovulation. These observations provide strong evidence for the view that oestrogen is responsible for the surge of prolactin on the afternoon of POe, and that the surge is accompanied by that of LH.


1960 ◽  
Vol XXXIV (III) ◽  
pp. 411-429 ◽  
Author(s):  
Melvin J. Fregly ◽  
Kenneth M. Cook

ABSTRACT The anti-thyroid drugs, thiouracil, propylthiouracil, and methimazole, prevented both development of elevated blood pressure and cardiac hypertrophy usually accompanying kidney encapsulation with latex envelopes. These drugs also reduced elevated blood pressure of rats with hypertension of 13 to 40 weeks' duration prior to drug administration. Addition of desiccated thyroid powder to diet containing an anti-thyroid drug overcame the anti-hypertensive effect of the latter. Withdrawal of thyroid powder only was followed by return of blood pressure to previous low level within 3 weeks. The results suggest that the anti-hypertensive effect of these drugs is related directly to the hypothyroidism produced rather than to extrathyroidal effects of the drugs. Comparison of potencies of the 3 drugs in terms of anti-hypertensive effect, inhibition of growth rate, increase in testicular size, and increase in thyroid size suggests that propylthiouracil and methimazole are equally potent per unit weight of drug. Thiouracil has approximately half the potency of the other two.


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