To evaluate daytime and nighttime carbon balance and assimilate export in soybean (Glycine max [L.] Merrill) leaves at different photon flux densities, rates of CO(2) exchange, specific leaf weights, and concentrations of sucrose and starch were measured at intervals in leaves of pod-bearing ;Amsoy 71' and ;Wells II' plants grown in a controlled environment room. Assimilate export was estimated...

Costs of plant defense are a key assumption in evolutionary ecology, yet their detection has remained challenging. Here we introduce a novel method for quantifying plant growth using the common milkweed Asclepias syriaca and repeated non-destructive size measurements to experimentally test for costs of defensive traits. We estimated mechanistic components of plant growth (relative growth rate, ...

Photosynthetic carbon assimilation by isolated chloroplasts and its associated oxygen evolution were measured simultaneously in a single simplified reaction mixture. Each showed an initial lag prior to the attainment of the maximal rate and the photosynthetic quotient was unity during the period of illumination. Following illumination an oxygen uptake was observed in the dark which was not acco...

Growth rates are of fundamental importance for plants, as individual size affects myriad ecological processes. We determined the factors that generate variation in RGR among 14 species of trees and shrubs that are abundant in subtropical Chinese forests. We grew seedlings for two years at four light levels in a shade-house experiment. We monitored the growth of every juvenile plant every two we...