# Biomass Refined: 99% of Organic Carbon in Soils
## 3 Results and Discussion
### Total Living Biomass
#### 3.7.4 Earthworms--Their Biomass and Processing of Topsoil Humans  
Earthworms are intimately associated with soil microbes, increasing their abundance up to \(\times\)1000 during passage of soil through the intestines in surficial or subterranean casts; furthermore, they disperse fungal propagules throughout the soil profile [145]. Ref. [146] suggested primarily a terrestrial origin of detritivorous Annelida, plus it is inferred early diversification of (mainly marine) annelids occurred before the Lower Cambrian [147]. Earliest Annelida may have emerged in the Cambrian around 518 million years ago and some late Ediacaran fossils may be older. This suggests annelids are equally likely to have originated on land or in mud then subsequently colonized littoral habitats as much as vice versa. Their emergence is thus in synchrony along with land plants during co-evolution between soils, fungi, and microbes. For earthworms (terrestrial Annelida), ref. [28] had \(\approx\)0.2 Gt C biomass based on 10 mg dry weight for a \"_characteristic_\" earthworm [148]. However, studies by [38, 67] allowing for terrain and based on biomass values from [145] as well as [PERSON] et al. are \(\times\)20 greater at \(\sim\)4.0 Gt C.  
In a recent article, ref. [149] suggested 0.9 Gt of earthworm dry matter available globally, but these authors note: \"_An illustration of the academic uncertainty is a report by [PERSON], which concluded that the global earthworm dry biomass amounts to 4.5 gigatones, fivefold higher than the estimate calculated above_\". At 50% carbon content, this is 2.25 Gt C in earthworms. Subsequent values ranged 2.33.6 Gt C, and a latest estimated mean value is 3.8 Gt C earthworm biomass based upon the totals from [148], simply doubled for terrain. table 9 in ref. [38] noted: \"_Earthworm biomass at 3.8 Gt C and Microbes at 209.6 Gt C are slightly higher than 2.3-3.6 Gt C and 200 Gt C, respectively, estimated by [PERSON] (2023: tab. 2) confirming importance of both groups to Soil Ecology_\". It is interesting that as well as the earthworm biomass in Figure 4 now being much more than Fish, with new values of \(\sim\)4.0 Gt C vs. \(\approx\)0.7 Gt C, earthworm abundance and biodiversity (with \(\sim\)35,000 expected earthworm species) are also much higher than fishes, indicating a need for a major shift in focus (or a \"_sea change_\"?). The Fish value of \(\approx\)0.7 Gt C from [28] compares to their estimate of total global fish biomass before human civilization across all sea depths at just \(\approx\)0.8 Gt C. This suggests there is not an ocean emergency so great nor so urgent as is often implied. Conversely, worms are dying, and populations have declined inordinately. This is not new information as [150, 151] found them eliminated completely from some agrichemical plots at Rothamstead that were acidified. If earthworm declines under global agrichemical [108] and UK forest habitats [152] are representative at \(-\)83% and \(-\)77%, respectively, then policies and practices for their restoration may offer practical solutions not just to biodiversity, but to topsoil loss and excess atmospheric CO\({}_{2}\). Revisiting [153] work a Century later, ref. [145] had mean earthworm surface casts dry mass of 105 t/ha/yr and about equal subsoil casting to sum 210 t/ha/yr. With 24 Gha of topsoil mantle, this is 5040 Gt/yr humus processing. At average cast carbon content around 4% ([PERSON], 2019--[[https://vermecology.wordpress.com/2019/11/11/earthwo](https://vermecology.wordpress.com/2019/11/11/earthwo)]([https://vermecology.wordpress.com/2019/11/11/earthwo](https://vermecology.wordpress.com/2019/11/11/earthwo)) rm-cast-carbon-storage-eccs/, accessed on 11 November 2024) implies 201.6 Gt C/yr, or the processing of nearly the entire terrestrial NPP, as to be expected for balanced Nature. An 83% earthworm loss is a disruptive effect that also offers remedy if field populations are restored five times, or to their former abundance glory.