I get the number of soil ants, termites, springtails, and mites per unit area for 10 biomes using the means in Table S4 of Rosenberg et al. (2023). I determine the number of soil nematodes per unit area by multiplying the number of soil arthropods from this table by 48.9, which is my estimate for the ratio between the number of soil nematodes and soil arthropods globally.
This resulted in cropland and pasture being the biomes with the least soil animals per unit area besides deserts, and xeric shrublands, which would very hardly be replaced by agricultural land. So I was thinking that increasing this would decrease soil-animal-years. However, from Figure 1a of Li et al. (2022) (summarised in White (2022)), which is below, it is unclear whether cropland and pasture have more or fewer soil nematodes than “primary habitat (undisturbed natural habitat)”, or “secondary habitat (recovering, previously disturbed natural habitat)”. For example, secondary habitat which is “unmanaged (no documented or observed direct human disturbance)” is estimated to have fewer soil nematodes than cropland and pasture which are unmanaged or “managed (more or less disturbed by various human activities like fertilization, tillage, grazing, logging, etc.)”. As a result, I am very uncertain not only about whether soil nematodes have positive or negative lives, but also about whether increasing agricultural land increases or decreases soil-animal-years.
Figure 7 of the meta-analysis of Pothula et al. (2019) also suggests it is very unclear whether agricultural land has more or fewer soil nematodes than forests.
I hadalreadyrecommended decreasing the uncertainty about whether soil animals have positive or negative lives over funding HIPF. However, I now feel like it does not even make sense to recommend global health interventions, or others which do not decrease the uncertainty about effects on soil animals or microorganisms.
Super interesting and helpful! Decreasing uncertainty seems highest value, when it comes to assessing effects of interventions on nematode populations.
One thing that I find striking and that I think illustrates this point well: most of the explained variance in Li et al’s models comes from data provider[1] systematic effects, rather than from environmental or land-use variables. (See their supplementary info).
Thanks, Nicolas. I agree one should prioritise decreasing the uncertainty about changes in the population of nematodes, and in their welfare over doing whatever naively seems to increase their welfare the most cost-effectively based on current best guesses.
One thing that I find striking and that I think illustrates this point well: most of the explained variance in Li et al’s models comes from data provider[1] systematic effects, rather than from environmental or land-use variables. (See their supplementary info).
Which is the relevant table? I did not find “provider” in the Supplementary Information.
Which is the relevant table? I did not find “provider”
Ah, right, good question. My understanding is that provider variance is modeled as a random effect.[1] I was looking at Supplementary Table 5: iiuc, provider effects explain R2_conditional—R2_marginal ~ 50% of the variance, whereas fixed effects explain 17% of the variance.
Paragraph 2.2.1: “Data provider was treated as a random effect to account for potential differences in sampling and analysis methods, and the selection of sampling sites”
This resulted in cropland and pasture being the biomes with the least soil animals per unit area besides deserts, and xeric shrublands, which would very hardly be replaced by agricultural land. So I was thinking that increasing this would decrease soil-animal-years. However, from Figure 1a of Li et al. (2022) (summarised in White (2022)), which is below, it is unclear whether cropland and pasture have more or fewer soil nematodes than “primary habitat (undisturbed natural habitat)”, or “secondary habitat (recovering, previously disturbed natural habitat)”. For example, secondary habitat which is “unmanaged (no documented or observed direct human disturbance)” is estimated to have fewer soil nematodes than cropland and pasture which are unmanaged or “managed (more or less disturbed by various human activities like fertilization, tillage, grazing, logging, etc.)”. As a result, I am very uncertain not only about whether soil nematodes have positive or negative lives, but also about whether increasing agricultural land increases or decreases soil-animal-years.
Figure 7 of the meta-analysis of Pothula et al. (2019) also suggests it is very unclear whether agricultural land has more or fewer soil nematodes than forests.
I had already recommended decreasing the uncertainty about whether soil animals have positive or negative lives over funding HIPF. However, I now feel like it does not even make sense to recommend global health interventions, or others which do not decrease the uncertainty about effects on soil animals or microorganisms.
Super interesting and helpful! Decreasing uncertainty seems highest value, when it comes to assessing effects of interventions on nematode populations.
One thing that I find striking and that I think illustrates this point well: most of the explained variance in Li et al’s models comes from data provider[1] systematic effects, rather than from environmental or land-use variables. (See their supplementary info).
“provider” being the person/group who supplied nematode data; ~50 providers contributed the dataset
Thanks, Nicolas. I agree one should prioritise decreasing the uncertainty about changes in the population of nematodes, and in their welfare over doing whatever naively seems to increase their welfare the most cost-effectively based on current best guesses.
Which is the relevant table? I did not find “provider” in the Supplementary Information.
Ah, right, good question. My understanding is that provider variance is modeled as a random effect.[1] I was looking at Supplementary Table 5: iiuc, provider effects explain R2_conditional—R2_marginal ~ 50% of the variance, whereas fixed effects explain 17% of the variance.
Paragraph 2.2.1: “Data provider was treated as a random effect to account for potential differences in sampling and analysis methods, and the selection of sampling sites”
Thanks. That makes sense to me. Here is a brief explanation of fixed and random effects from Gemini.