Historical trends and drivers of the laterally transported terrestrial dissolved organic carbon to river systems

Historical trends and drivers of the laterally transported terrestrial dissolved organic carbon to river systems

Dissolved organic carbon (DOC) represents a critical component of terrestrial carbon (C) cycling and is a key contributor to the carbon flux between land and aquatic systems. Historically, the quantification of environmental factors influencing DOC leaching has been underexplored, with a predominant focus on land use changes as the main driver. In this study, the process-based terrestrial ecosystem model JULES-DOCM was utilized to simulate the spatiotemporal patterns of DOC leaching into the global river network from 1860 to 2010. This study reveals a 17 % increment in DOC leaching to rivers, reaching 292 Tg C yrโˆ’1 by 2010, with atmospheric CO2 fertilization identified as the primary controlling factor, significantly enhancing DOC production and leaching following increased vegetation productivity and soil carbon stocks. To specifically quantify the contribution of CO2 fertilization, a factorial simulation approach was employed that isolated the effects of CO2 from other potential drivers of change.

The research highlights distinct regional responses. While globally CO2 fertilization is the dominant factor, in boreal regions, climate change markedly influences DOC dynamics, at times exceeding the impact of CO2. Temperate and sub-tropical areas exhibit similar trends in DOC leaching, largely controlled by CO2 fertilization, while climate change showed an indirect effect through modifications in runoff patterns. In contrast, the tropics show a relatively low increase in DOC leaching, which can be related to alterations in soil moisture and temperature.

Additionally, the study re-evaluates the role of land use change in DOC leaching, finding its effect to be considerably smaller than previously assumed. These insights emphasize the dominant roles of CO2 fertilization and climate change in modulating DOC leaching, thereby refining our understanding of terrestrial carbon dynamics and their broader implications on the global C budget.

Historical trends and drivers of the laterally transported terrestrial dissolved organic carbon to river systems

Forest carbon stock development following extreme drought-induced dieback of coniferous stands in Central Europe: a CBM-CFS3 model application

We analyze the forest carbon stock development following the recent historically unprecedented dieback of coniferous stands in the Czech Republic. The drought-induced bark-beetle infestation resulted in record-high sanitary logging and total harvest more than doubled from the previous period. It turned Czech forestry from a long-term carbon sink offsetting about 6% of the country’s greenhouse gas emissions since 1990 to a significant source of CO2 emissions in recent years (2018โ€“2021). In 2020, the forestry sector contributed nearly 10% to the country’s overall GHG emissions. Using the nationally calibrated Carbon Budget Model of the Canadian Forest Sector (CBM-CFS3) at a regional (NUTS3) spatial resolution, we analyzed four scenarios of forest carbon stock development until 2070. Two critical points arise: the short-term prognosis for reducing current emissions from forestry and the implementation of adaptive forest management focused on tree species change and sustained carbon accumulation.

ForestNavigator EGU 2024 session

ForestNavigator EGU 2024 session

ForestNavigator is convening the EGU24 session on “๐‘€๐‘œ๐‘‘๐‘’๐‘™๐‘–๐‘›๐‘” ๐‘Ž๐‘›๐‘‘ ๐‘’๐‘ฅ๐‘๐‘™๐‘œ๐‘Ÿ๐‘–๐‘›๐‘” ๐‘“๐‘œ๐‘Ÿ๐‘’๐‘ ๐‘ก ๐‘’๐‘๐‘œ๐‘ ๐‘ฆ๐‘ ๐‘ก๐‘’๐‘š๐‘  ๐‘ข๐‘›๐‘‘๐‘’๐‘Ÿ ๐‘“๐‘ข๐‘ก๐‘ข๐‘Ÿ๐‘’ ๐‘๐‘™๐‘–๐‘š๐‘Ž๐‘ก๐‘’ ๐‘Ž๐‘›๐‘‘ ๐‘š๐‘Ž๐‘›๐‘Ž๐‘”๐‘’๐‘š๐‘’๐‘›๐‘ก”. Submit your abstract and join us…

Monitoring future forests

Monitoring future forests

Forests play a key role in mitigating climate change, protecting and restoring biodiversity, securing the provisioning of many ecosystem services and developing the bioeconomy…