I would still be interested to see estimates of eg mice per acre in forests vs farms
Brian Tomasik has some estimates. For rainforest, the density of wild terrestrial arthropods as a fraction of the global mean is 1.02 to 5 (95 % confidence interval). For Cerrado, which is a proxy for farmland, it is 0.70 to 3.00. I fitted lognormal distributions to these values, and got that the expected value for the density of wild terrestrial arthropods in rainforests is 72.4 % (= 1.55/​0.899 − 1) higher than that for Cerrado. Overall, it looks like there are more wild terrestrial arthropods in forests, but it is not super clear, judging from the overlap between the 95 % confidence intervals.
I’m not sure yet whether this deforestation effect is reversible.
Yes, I do not know either. From the point of view of resilience against ASRSs, it would be good if abandoned farmland remained deforested such that it could quickly start being used if needed.
Thanks! It’s worth noting that the rainforest and Cerrado numbers in that piece are very rough guesses based on limited and noisy data. As one friend of mine would say, I basically pulled those numbers out of my posterior (...distribution). :) Also, even if that comparison is accurate, it’s just for one region of the world; it may not apply to the difference between, e.g., temperate forests and grasslands. All of that said, my impression is that crop fields do tend to have fewer mammals and birds than wild grassland or forest. For birds, see the screenshot of a table in this section.
You are welcome!
Brian Tomasik has some estimates. For rainforest, the density of wild terrestrial arthropods as a fraction of the global mean is 1.02 to 5 (95 % confidence interval). For Cerrado, which is a proxy for farmland, it is 0.70 to 3.00. I fitted lognormal distributions to these values, and got that the expected value for the density of wild terrestrial arthropods in rainforests is 72.4 % (= 1.55/​0.899 − 1) higher than that for Cerrado. Overall, it looks like there are more wild terrestrial arthropods in forests, but it is not super clear, judging from the overlap between the 95 % confidence intervals.
Yes, I do not know either. From the point of view of resilience against ASRSs, it would be good if abandoned farmland remained deforested such that it could quickly start being used if needed.
Thanks! It’s worth noting that the rainforest and Cerrado numbers in that piece are very rough guesses based on limited and noisy data. As one friend of mine would say, I basically pulled those numbers out of my posterior (...distribution). :) Also, even if that comparison is accurate, it’s just for one region of the world; it may not apply to the difference between, e.g., temperate forests and grasslands. All of that said, my impression is that crop fields do tend to have fewer mammals and birds than wild grassland or forest. For birds, see the screenshot of a table in this section.
Fantastic, thanks for sharing!