The James San Jacinto Mountains Reserve is a networked ecological observatory and a test site for experimental embedded networked sensors (ENS). The primary long-term objective is to design, deploy, and evaluate ENS and instrumented platforms for measuring ecological variables. One fundamental challenge for soil research is the spatial and temporal heterogeneity of soil processes, therefore, we deployed a dense array of wireless soil sensors to study rhizosphere soil processes. Using natural spatial gradients within a mountain mixed conifer forest we determined that annual soil respiration rates varied from 1000 to 375 g CO2 m-2 y-1 between a close and an open forest understory sites. Continuous measurements from CO2 sensors have shown differences in diurnal patterns and seasonal shifts in diurnal hysteretic responses of soil respiration at the two forest sites. To study root production and turnover we have developed an automated minirhizotron, which is controlled via a wireless network connection to collect root images. Information from manual minirhizotron images has shown the importance of continuous monitoring of the rhizosphere to detect rapid changes in root dynamics. ENS technology is leading to new understanding of spatio-temporal rhizosphere processes.