New uses for old tools: Reviving Holdridge Life Zones in soil carbon persistence research

Hermann F. Jungkunst,Melanie Brunn,Jan Goepel,Thomas Horvath,Simone Ott

doi:10.1002/jpln.202100008

Abstract

AbstractGrowing evidence suggests that climate classification facilitates the identification of zones that either agree or disagree with processes explaining soil organic carbon (SOC) persistence. Already forty years ago, Post et al. (1982) posited that the strict temperature and precipitation‐based classification defining the Holdridge Life Zones (HLZ) provides a descriptive tool to guide our understanding of the heterogeneous distribution of global SOC stocks. Here we argue that this classification has the potential for describing SOC persistence by linking top‐down and bottom‐up approaches from different scales, which allows selection of individual regional relevancies necessary to manage and track the fate of our largest terrestrial carbon (C) reservoir.

Highlights

Growing evidence suggests that climate classification facilitates the identification of zones that either agree or disagree with processes explaining soil organic carbon (SOC) persistence
Processes of SOC persistence differ with climate, and it will be challenging to identify the underlying dominating pedogenic process controlling SOC
We agree with Hall et al (2020) that climate classification holds the potential to reunite diverging explanations for SOC persistence to complementarity

Summary

The old tool and the new challenge

Almost 40 years ago, Post et al (1982) introduced how helpful the Holdridge Life Zones (HLZ) classification is in explaining and describing the regional differentiation of soil organic carbon (SOC) stocks on a global scale. They argued it to be ‘‘important to establish the relationships between the geographical distribution of SOC and climate as a basis for assessing the influence of changes’’ suggesting that the geographical location, in terms of climate, influences the SOC distribution. 2015; Lehmann et al, 2020) and propose the HLZ classification as an effective and descriptive tool to guide research questions leading to a better understanding of climate soil feedback mechanisms

Approach

Carbon stocks in the Holdridge Life Zones

Beyond climate control of SOC stocks

Findings

Conclusion