Category: Non classé

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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New measurements of soil water content with a neutron probe in drought conditions

This summer, new measurements of soil water content were carried out by Cyril Dejean (Irstea G-EAU unit in Montpellier) on the OPTMix plots using a neutron probe. These new measurements carried out during a period of severe drought (14/08/2018) will complete the range of measurements required to calibrate the soil water content sensors (CS616 – …

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Article published: Better predicting sessile oak and Scots pine growth in a changing climate

An article has just been published in “Agricultural and Forest Meteorology” on the growth of sessile oak and Scots pine. The goal of this work was to integrate climatic variables into models to better predict growth in the context of climate change. This work was performed using IGN data and ring-width data collected in the …

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Article published: The effect of deer browsing and understory light availability on stump mortality and sprout growth capacity in sessile oak

An article presenting results on the effect of deer browsing and understory light availability on stump mortality and sprout growth capacity in sessile oak has just been published in Forest Ecology and Management. The work was carried out on parts of the experimental facility OPTMix. The article is the result of work carried out by …

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Monitoring soil microbial activity

Promoted by Stéphane Bazot from UMR 8079, Laboratory Ecology, Systematics and Evolution of Paris-sud University, a team led by Gaëlle Vincent came to OPTMix in March and mid-June for two campaigns to monitor soil microbial activity. Soil samples were taken for structural analyzes of the communities of bacteria, archaea and fungi. To complete, soil respiration …

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