Microbial nutrient limitation in tropical forest soils determined using the V-T model contradicts the traditional view that C is the major limiting element

Mori Taiki

doi:10.3759/tropics.ms22-03

<p>Traditionally, microbial activity in tropical forest soils has been thought to be limited predominantly by carbon (C) availability, prompting investigations of whether phosphorus (P) is a stronger limiting factor (next to C) than other nutrients. However, a recently developed enzyme vector model has sometimes shown that P or nitrogen (N), but not C, is the predominant limiting factor, likely due to biased C vs. N vs. P limitation thresholds. In the latest update of this approach (the V-T model) this problem was addressed by revising the threshold, or balance point, that represents the enzymatic ratio at which microbial metabolism is not limited by nutrients. However, it remains unclear whether results obtained using the V-T model are consistent with the traditional view that C is the predominant limiting element for soil microbial activity. In this short note, I analyzed the microbial resource limitations of tropical forest soils using the V-T model approach based on previously published global data, and discussed the consistency of the results with the traditional view. The V-T model results showed that up to 78 % of the data indicated that P, and not C, was the limiting element, contradicting the traditional view. This finding may have been the result of a bias in the balance point toward C limitation (i.e., the balance point, or threshold, used for determining microbial nutrient limitation is under C-limited condition, rather than under no nutrient limitation), resulting in underestimation of C limitation. The present study suggest that the V-T model requires further improvement; however, the traditional view of C limitation of soil microbial activity is also poorly supported, and further direct observation is needed.</p>

Microbial nutrient limitation in tropical forest soils determined using the V-T model contradicts the traditional view that C is the major limiting element

Search this article

Description

Journal

Citations (2)*help

References(30)*help

Related Projects

Keywords

Details 詳細情報について

Export

Report a problem