Biosynthesis of bioactive phytochemicals in plant tissues is highly ordered and effective by harvesting times, including different developmental stages and seasonal changes. Both were complex factors in environmental variables that significantly regulate many physiological and behavioral processes, such as shifts in chemical and microbial rhizosphere community composition. Substantial differences in biological activities may also occur.

Plant geographic origin significantly influenced relative concentrations of nutrient content and morphology with variations between origins of the same species (i.e., genetic factors). Altitudinal gradients differ in several factors, including atmospheric pressure, precipitation, solar radiation, and soil nutrients. Because low temperatures at high altitudes are likely to limit decomposition and other soil processes, soil organic carbon (C) concentration may increase. In contrast, the availability of soil nutrients (e.g., N and P) may decrease with increasing elevation. Moreover, climatic factors, indicated by air temperature, precipitation, and UV radiation, can also vary with altitudes, thus creating complex environmental changes along the altitudinal gradients-microbial communities.