The substantial influences of non-resource conditions on recovery of plants: A case study of clipped Spartina alterniflora asphyxiated by submergence

Because non-resource factors, which can not be utilized by organisms but can influence biological growth, are important growing conditions for species, the study of the effect of these factors on the recovery of disturbed plants can contribute to the management of vegetation. Spartina alterniflora (smooth cordgrass), having invaded many marshes, was clipped to test the effects of submergence time and soil salinity on the recovery, as well as their underlying mechanisms. The results showed that salinity did not significantly affect the recovery of clipped invader, while longer-time submergence led to poorer recovery. Pentose phosphate pathway plays primary role in carbon metabolism of S. alterniflora roots. Along with the increase of submergence time, however, the activity of glucose-6-phosphate dehydrogenase in the roots of clipped S. alterniflora decreased; and the activities of lactate dehydrogenase and alcohol dehydrogenase firstly increased and then decreased. Ultimately, the activities of the three dehydrogenases became zero and thus asphyxiated the roots. Consequently, the clipped invader died after submergence of 12 days. Our case study demonstrates the recovery of invasive plants after disturbance depends on some non-resource conditions which can significantly influence the carbon metabolism of remaining parts. Thus, it can be predicted that identifying such non-resource conditions can help to develop an environment-specific management regime. The physical methods for removing aboveground biomass can be used to control invasive Spartina spp. in long-time submergence zones, whereas such methods need to be optimised for other zones.