Thanks for the great points, David! I strongly upvoted your comment.
I presented results for cropland replacing replacing temperate grasslands, savannas, and shrublands, but I consider many other replacements in my sheet. I estimate tropical and subtropical forests have 1.76 (= 5.25*10^6/​(2.99*10^6)) times as many soil nematodes, mites, and springtails per m2 as tropical and subtropical grasslands, savannas, and shrublands, and that temperate forests have 1.42 (= 8.92*10^6/​(6.30*10^6)) times as many soil nematodes, mites, and springtails per m2 as temperate grasslands, savannas, and shrublands. These ratios are higher than 1, so I think replacements of cropland with forests would tend to decrease soil-animal-years more than suggested by the results I presented in my post. This would strengthen my point that effects on soil animals are much larger than those on directly affected animals. However, I very much agree with your broader point that one should consider a mix of cropland and pasture replacing a mix of biomes (instead of just cropland replacing a single biome, as I did).
I also agree that regional and seasonal differences should be taken into account. Table S4 of Rosenberg et al. (2023)has not only the mean densities I used for each biome, but also 95 %confidence intervals(CIs), and the number of sites regarding each estimate. Acari are mites, collembola are springtails, formicidae are ants, and isoptera are termites.
Overall, I am still thinking that increasing agricultural-land-years is a good heuristic to decrease soil-animal-years. However, I am only confident that the effects on soil animals are larger than those on farmed animals. It would be great to have way more research decreasing the uncertainty about the effects on soil animals, not only about their welfare per animal-year, but also about the changes in their animal-years.
However, I very much agree with your broader point that one should consider a mix of cropland and pasture replacing a mix of biomes (instead of just cropland replacing a single biome, as I did).
I have just published a post where I consider this.
Thanks for the great points, David! I strongly upvoted your comment.
I presented results for cropland replacing replacing temperate grasslands, savannas, and shrublands, but I consider many other replacements in my sheet. I estimate tropical and subtropical forests have 1.76 (= 5.25*10^6/​(2.99*10^6)) times as many soil nematodes, mites, and springtails per m2 as tropical and subtropical grasslands, savannas, and shrublands, and that temperate forests have 1.42 (= 8.92*10^6/​(6.30*10^6)) times as many soil nematodes, mites, and springtails per m2 as temperate grasslands, savannas, and shrublands. These ratios are higher than 1, so I think replacements of cropland with forests would tend to decrease soil-animal-years more than suggested by the results I presented in my post. This would strengthen my point that effects on soil animals are much larger than those on directly affected animals. However, I very much agree with your broader point that one should consider a mix of cropland and pasture replacing a mix of biomes (instead of just cropland replacing a single biome, as I did).
I also agree that regional and seasonal differences should be taken into account. Table S4 of Rosenberg et al. (2023) has not only the mean densities I used for each biome, but also 95 % confidence intervals (CIs), and the number of sites regarding each estimate. Acari are mites, collembola are springtails, formicidae are ants, and isoptera are termites.
Overall, I am still thinking that increasing agricultural-land-years is a good heuristic to decrease soil-animal-years. However, I am only confident that the effects on soil animals are larger than those on farmed animals. It would be great to have way more research decreasing the uncertainty about the effects on soil animals, not only about their welfare per animal-year, but also about the changes in their animal-years.
I have just published a post where I consider this.