The Forest Observation System, building a global reference dataset for remote sensing of forest biomass

Forest biomass is an essential indicator for monitoring the Earth's ecosystems and climate. It is a critical input to greenhouse gas accounting, estimation of carbon losses and forest degradation, assessment of renewable energy potential, and for developing climate change mitigation policies such as REDD+, among others. Wall-to-wall mapping of aboveground biomass (AGB) is now possible with satellite remote sensing (RS). However, RS methods require extant, up-to-date, reliable, representative and comparable in situ data for calibration and validation. Here, we present the Forest Observation System (FOS) initiative, an international cooperation to establish and maintain a global in situ forest biomass database. AGB and canopy height estimates with their associated uncertainties are derived at a 0.25 ha scale from field measurements made in permanent research plots across the world's forests. All plot estimates are geolocated and have a size that allows for direct comparison with many RS measurements. The FOS offers the potential to improve the accuracy of RS-based biomass products while developing new synergies between the RS and ground-based ecosystem research communities.

[The ophthalmological symptoms of chiasmatic gliomas in children in the pre- and postoperative periods]

The paper outlines the ophthalmological symptomatology in 61 children aged 2.5 to 15 years who had great and giant chiasmal gliomas. The ophthalmological symptomatology among the first clinical manifestations was found in 86.9% of cases and remained prevalent throughout the follow-up. There was a correlation between the status of visual functions and the site of a tumor. The tumor affected mainly the chiasma in 6.6% of cases, the chiasma and the both optic nerves in 26.2%, the chiasma and an optic nerve in 62.2%. The ophthalmological and neurological symptomatologies are of value in choosing a surgical treatment. A subtotal and partial removal of the tumor was performed in 51 and 10 patients, respectively. Its removal resulted in an improvement and stabilization of visual functions in 14.3 and 41.1% of cases, respectively. Thirty-three patients were followed up for 4 months to 8 years. Visual improvement occurred in 36.4% in the late period. There was a relapse in 9.1% of cases.

[The neuro-ophthalmological symptom complex in the clinical picture of craniopharyngiomas (the pre- and postoperative periods)]

The comparative analysis of the neuro-ophthalmological symptomatology of 310 patients (202 children and 108 adult persons) revealed the specific features of a disease with age in relation to the baseline growth, site and primarily extent of a tumor. A monitoring of visual functions was made in the pre- and postoperative periods (early and late). The comparison of the visual function prior to surgery, their dynamics in the postoperative period and the analysis of the anatomic and topographic relationships in the chiasm-sellar region, the specific features of tumor removal revealed the pathogenesis of visual disorders in craniopharyngiomas, including after tumor removal. Risk factors for visual dysfunctions were defined.

[Results of surgical treatment of gliomas of the optic nerve]

The work discusses the catamnestic data on 55 children aged from 10 months to 17 years who underwent operation for glioma of the optic nerve by the one-stage cranio-orbital method. A recurrent tumor was found in 6 patients in postoperative periods of 1 to 5 years. Its source was a nonremoved intracanalicular part of the optic nerve involved in the tumor. Chronic trophic uveitis was encountered in some patients after the operation, which led to subatrophy of the eyeball. Exacerbation of uveitis simulated growth of the tumor into the optic disk in some cases, due to which enucleation of the eyeball was performed.