Acid/ Base

Hi, I have a question regarding to acid and base. I remember in the lecture, Sandra mentioned that earthworms prefer basic - neutral (humid) conditions. But isn't basic usually happen in arid regions?

Alkaline soils are common in 1) regions with parent material high in bases, e.g. limestone and/or 2) semi-arid regions, like the Okanagan in B.C. where evaporation is greater than precipitation (for a significant part of the year), so that base forming cations (salts) accumulate at or near the soil surfaces. In contrast, in wetter regions, like Vancouver, the high precipitation will "wash" bases (Na, Ca, Mg, K) from the soil profile (i.e. via leaching).

Earthworms: nuetral pH is ideal for earthworms, but they can adapt to slightly acidic soil pH; i.e. pH 6-7

Note that pH is influenced by climate, but not determined by climate alone.... soil pH reflects the combined effects of soil-forming factors + management.