Clonal plasticity in response to reciprocal patchiness of light and nutrients in the stoloniferous herb Glechoma longituba L.

Interconnected ramets of clonal plants can functionally specialize in the uptake of resources from aboveground and/or underground sources. Ramet pairs of the clonal stoloniferous herb Glechoma longituba L. were grown in spatially heterogeneous environments with complementary availability of light and nutrients. Plasticity with respect to root-shoot ratio, fitness-related traits (biomass, number of ramets and dry weight per ramet), morphological traits (lamina area, root length) were experimentally examined. The aim was to understand the adaptation of G. longituba to an environment with reciprocal patchiness of light and soil nutrients by plasticity in its root-shoot ratio and clonal morphology. The results showed that the performance of ramets growing in patches with high light intensity and low soil nutrients into the adjacent opposite patches was increased in terms of fitness-related traits. However, the performance of those from patches with low light intensity and high soil nutrients into the adjacent opposite patches was not changed. The root-shoot ratio and clonal morphology were plastic. Morphological traits such as lamina area and root length were altered in a way that enhanced the capture of light resources and soil nutrients. Apparent reciprocal resource transport between the ramets in an environment of reciprocal patchiness of resources can enhance the growth of ramets with complementary resource deficiencies.