Water table depth modulates productivity and biomass across Amazonian forests

0 avis

Water table depth modulates productivity and biomass across Amazonian forests

Archive ouverte

Edité par CCSD ; Wiley -

International audience. Aim: Water availability is the major driver of tropical forest structure and dynamics. Most research has focused on the impacts of climatic water availability, whereas remarkably little is known about the influence of water table depth and excess soil water on forest processes. Nevertheless, given that plants take up water from the soil, the impacts of climatic water supply on plants are likely to be modulated by soil water conditions. Location: Lowland Amazonian forests. Time period: 1971–2019. Methods: We used 344 long-term inventory plots distributed across Amazonia to analyse the effects of long-term climatic and edaphic water supply on forest functioning. We modelled forest structure and dynamics as a function of climatic, soil-water and edaphic properties. Results: Water supplied by both precipitation and groundwater affects forest structure and dynamics, but in different ways. Forests with a shallow water table (depth <5 m) had 18% less above-ground woody productivity and 23% less biomass stock than forests with a deep water table. Forests in drier climates (maximum cumulative water deficit < −160 mm) had 21% less productivity and 24% less biomass than those in wetter climates. Productivity was affected by the interaction between climatic water deficit and water table depth. On average, in drier climates the forests with a shallow water table had lower productivity than those with a deep water table, with this difference decreasing within wet climates, where lower productivity was confined to a very shallow water table. Main conclusions: We show that the two extremes of water availability (excess and deficit) both reduce productivity in Amazon upland (terra-firme) forests. Biomass and productivity across Amazonia respond not simply to regional climate, but rather to its interaction with water table conditions, exhibiting high local differentiation. Our study disentangles the relative contribution of those factors, helping to improve understanding of the functioning of tropical ecosystems and how they are likely to respond to climate change.

Langue: en

Indexation

Consulter en ligne

Consulter le document

Suggestions

Du même auteur

Long-term thermal sensitivity of Earth’s tropical forests

Archive ouverte | Sullivan, Martin, J P | CCSD

International audience. The sensitivity of tropical forest carbon to climate is a key uncertainty in predicting global climate change. Although short-term drying and warming are known to affect forests, it is unknow...

Taking the pulse of Earth's tropical forests using networks of highly distributed plots

Archive ouverte | Blundo, Cecilia | CCSD

International audience. Tropical forests are the most diverse and productive ecosystems on Earth. While better understanding of these forests is critical for our collective future, until quite recently efforts to me...

Tree mode of death and mortality risk factors across Amazon forests

Archive ouverte | Esquivel-Muelbert, Adriane | CCSD

Corrections available at : https://doi.org/10.1038/s41467-020-20537-x. International audience. The carbon sink capacity of tropical forests is substantially affected by tree mortality. However, the main drivers of t...

Chargement des enrichissements...