I was reading this paper: https://link.springer.com/article/10.1023/A:1011398431524, which makes claims based on the the idea that frost can increase soil fertility. How/Why will frost increase the fertility of the soil? I was always under the assumption that frost was bad for soil and plants in general.
I found this article on why frost increase soil fertility - specifically nutrient density in the soil. 101 years old!
The Occurrence of Bacteria in Frozen Soil E. C. Harder Botanical Gazette Vol. 61, No. 6 (Jun., 1916), pp. 507-517 https://www.jstor.org/stable/2469064?seq=3#fndtn-page_scan_tab_contents
Relevant text pasted below. In short: it is bacterial action and nitrogen fixation which contributes to soil fertility. Freezing increases bacterial population and these metabolic activites. The theory is that freezing kills bacterial predators on higher trophic levels (protozoans) but the bacteria live and thrive in the absence of predators.
From the introduction (bottom of page 167 and top of page 168) of the paper you linked (Masters and McMillan 2001)
We use newly available worldwide climate data to quantify the prevalence of seasonal frosts, hypothesizing that what the tropics have in common is an absence of winter frost, "the great executioner of nature" (Kamarck, 1976, p.17). A hard frost that kills exposed organisms in nature could have a major influence on the productivity of human investment in agriculture and health, by reducing competition from pests, pathogens and parasites.