Author's posts
Mar 12
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 …
Mar 12
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.
Mar 12
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 …
Dec 10
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…
Nov 26
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.
Oct 19
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 …
Oct 02
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 …
Oct 02
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 …
Sep 13
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 …
Sep 13
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 – …
