What does the ‘chat’ tell us about participation and engagement in online video conferencing?

Although much is known about the experiential nature of online conferencing, we know less about actual participation and engagement. This paper investigates delegate interactions in the “parallel chat” function of a video platform during an online medical education conference. We collected 813 unique messages, posted while speakers presented on a digital stage. We used descriptive statistics to summarize message/chat content in terms of participant categories and topic. 23% of delegates posted in the chat. However, to go beyond these dimensions, we used conversation analytic methods to identify the actions accomplished in messages and their interconnectedness. We developed a coding scheme to report this analysis across the complete dataset. We found that messages mostly comprised positive assessments (“Wonderful talk!”) and appreciations (“Thank you!”). ‘Second’ messages were more common than initiations or ‘first’ messages, indicating extensive engagement between participants. Few messages received no response. Delegates also formulated what speakers said to develop ‘learning moments’ in the chat. Overall, we argue that a richer and more precise understanding of participation and engagement in video conferencing can be achieved by analysing actual participation and its content, rather than relying only on post-hoc reports and surveys. Data are in British English

Drastic Vegetation Change in the Guajira Peninsula (Colombia) during the Neogene

Dry biomes occupy ~35% of the landscape in the Neotropics, but these are heavily human-disturbed. In spite of their importance, we still do not fully understand their origins and how they are sustained. The Guajira Peninsula in northern Colombia is dominated by dry biomes and has a rich Neogene fossil record. Here, we have analyzed its changes in vegetation and precipitation during the Neogene using a fossil pollen and spore dataset of 20 samples taken from a well and we also dated the stratigraphic sequence using microfossils. In addition, we analyzed the pollen and spore contents of 10 Holocene samples to establish a modern baseline for comparison with the Neogene as well as a study of the modern vegetation to assess both its spatial distribution and anthropic disturbances during the initial stages of European colonization. The section was dated to span from the latest Oligocene to the early Miocene (~24.2 to 17.3 Ma), with the Oligocene/Miocene boundary being in the lower Uitpa Formation. The early Miocene vegetation is dominated by a rainforest biome with a mean annual precipitation of ~2,000 mm/yr, which strongly contrasts with Guajira\u27s modern xerophytic vegetation and a precipitation of ~300 mm/yr. The shift to the dry modern vegetation probably occurred over the past three millions years, but the mechanism that led to this change is still uncertain. Global circulation models that include the vegetation could explain the ancient climate of Guajira, but further work is required to assess the feedbacks of vegetation, precipitation, and CO2

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

International audienceForest 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