This book covers correlation and combined disciplinary aspects implying the use of secondary metabolites (SMs) of different plant species for control and monitoring of environment states. Phyhemical management of ecological systems represents an integrative field aiming for determination/evaluation of environment conditions from qualitative and quantitative analysis of plant metabolites. Plants respond to environmental conditions through productions of secondary metabolites. SMs represent highly variable and sensitive phyompounds because of their small produced amounts, high structural variability and diversified activities. These characteristics make variations of SMs in plants to be highly informative on environmental conditions, physiological states and biological interactions. Qualitative and quantitative variations of SMs in plants are subject to correlation analyses to highlight links between biotic/abiotic conditions and plant chemical patterns.