<p>American Demographics’ data bank contains, at the present time, over 2500 variable for 151 countries with a 1975 population of approximately 300,000 or more (as assessed by the United Nations
Arbuscular mycorrhiza is a mutualistic symbiosis between the majority of land plants and fungi from the phylum Glomeromycota. The fungi are obligate symbionts and cannot be cultivated without their ho
