Water & Climate

Shedding light on how much carbon tropical forests can absorb


Calculating the amount of carbon that tropical forests sequester requires examining a wider range of factors than most researchers undertake, according to a new report.

The authors of the new study published in Scientific Reports, investigated how many species are needed for tropical ecosystem functioning and C sequestration.

Lead author Florian Hofhansl, a postdoc researcher with the International Institute for Applied Systems Analysis said: “We wanted to find out how much detail we need to know in order to make valid assumptions in terms of the strength of tropical carbon sinks.”

The study showed that abiotic and biotic factors interact to determine how much C can be stored, based on the availability of other resources such as water and nutrients.

Statistical path modelling revealed that apart from climatic factors such as temperature and rainfall, factors like soil texture and chemistry were important.

The study specifically looked at differences between trees, palms, and lianas (long-stemmed, woody vines that climb). Each differed in the amount of C stored. For example, fast-growing lianas do not store as much C as a tree stem.

Traditional large-scale projections of global change effects on tropical forests ignore the underlying factors triggering differences in plant community composition. Remote sensing techniques typically integrate over large spatial areas, averaging out local landscape diversity, while vegetation models usually ignore the variable response of different plant communities to climatic factors.

Dr Hofhansl said: “Our analyses highlighted that it is important to channel knowledge form multiple scientific disciplines, such as botany (identifying species), plant ecology (identifying functional strategies), and geology (identifying differences in soil types). “

Source: International Institute for Applied Systems Analysis