Time lag effects of rainfall inside a Platycladus Orientalis plantation forest in the Beijing Mountain Area, China SPATIAL VARIATION OF SAP FLOW OF QUERCUS ACUTISSIMAAND ITS LAG EFFECT DURINGSPRING Dynamics of sap flow density in stems of typical desert shrub Calligonum mongolicum and its responses to environmental variables. Time lag effect between poplar’s sap flow velocity and microclimate factors in agroforestry system in west Liaoning Province. Spatiotemporal variations of vegetation cover in Zhejiang Province and their relations to eco-climatic indices. Study the change of NDVI and climate factors and carrying capacity and their correlation in Maqu County, Gansu Analysis on Trunk Sap Flow Time Lag Effect of Sophora japonica f. pendula Compared to Meteorological Factors