Category: Non classé

LAI measurements with the needles method

As part of thesis project of Maxime Brière (thesis 2019-2021 supervised by Eric Dufrêne, UMR ESE), LAI estimates in oak mono-specific plots were carried out on February 12, 2019. The LAI of the plots was estimated with the needles method which consists in counting the number of fallen leaves of the year on the ground …

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OPMTix annual meeting, 8, 10 and 11 january 2019

The annual meeting of the project took place on 8, 10 and 11 January, 2019 at Irstea Nogent-sur-Vernisson. These days were an opportunity to review the past year in terms of management and maintenance and also to discuss the scientific aspects: the scientific studies done and those planned and to discuss new experiments or new …

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Digging pits in high tree density plots: soil description, soil sampling and sensor installation

From 10 to 18th of December, 2018, pits have been dug in high tree density plots. The following operations were performed: a fine soil description, soil sampling in the different horizons, installation of sensors for the measurement of soil moisture, level of the water table and soil temperature.

Article published: during severe drought, Sessile oak and Scots Pine growing in mixed stands have different water uptake depths

An article has just been published in the “Plant science” journal on the water uptake depths of sessile oak and Scots pine growing in mixed stands during a severe drought. The data were collected in 2016 on the OPTMix plots. To determine the water uptake depths, isotopic signatures (oxygen) of wood and soil during the …

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Digging pits in high tree density plots: soil description, soil sampling and sensor installation

From December 10, 2018, pits will be dug in high tree density plots. These pits will allow a fine soil description, soil sampling in the different horizons and the installation of sensors for the measurement of the soil moisture, the level of the water table and the soil temperature. Pictures coming soon…

OPTMix annual meeting, January 8, 10 and 11, 2019

The OPTMix annual meeting will take place on January 8, 10 and 11, 2019 at Irstea Nogent-sur-Vernisson.

Visits on OPTMix

On Thursday, October 18th, two groups visited the OPTMix device: in the morning: 36 students from the Mesnières Forest High School in Normandy. For the occasion, Richard Chevalier (Irstea) who was their contact, was present to welcome them and present Irstea. in the afternoon: about fifteen people from the regional CNPF, mainly the Presidents and …

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Article published: How do mixing tree species and stand density affect seasonal radial growth during drought events?

An article has just been published in “Forest Ecology and Management” . This article deals with the effects of species interactions and stand density on radial growth during a drought event. To perform this study, the intra-annual growth of oaks and pines was measured for 3 years on 216 trees distributed over 18 plots of …

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Maintenance of data loggers and sensors

A total of 22 dataloggers and 494 sensors are continuously operating on OPTMix plots. A maintenance operation of the dataloggers and sensors was carried out from 2018-09-11 to 2018-09-14. The purpose of this operation was to review all the sensors returning abnormal data in order to identify the origin of these anomalies (defective sensors, connection …

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Calibration of the 66 light sensors

The 66 light sensors of the OPTMix device were disassembled from the data loggers during a short period in order to carry out a calibration using reference sensors in an open ground. This calibration will update the correction coefficients used to convert the millivolts returned by the sensors into a unit of measurement of solar …

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