Sinks for plant surplus carbon explain several ecological phenomena

Abstract Plants engage in many processes and relationships that appear to be wasteful of the high-energy compounds they produce through carbon fixation photosynthesis. For example, living trees keep leafless tree stumps alive ( i.e. respiring) support shaded understory by sharing carbohydrates root grafts or mycorrhizal fungal networks. exude a diverse array organic from their roots leaves, which abundant rhizosphere phyllosphere microbiomes. Some plants release substantial amounts sugar via extra-floral nectaries, enrich throughfall alter lichen communities beneath canopy. Large photosynthetically fixed are transferred associates such as fungi N-fixing micro-organisms. also respire C an alternative pathway does not generate ATP. Rates each these highest when growing under mild-to-moderate deficiencies nutrients water. During this stage deficiency, aboveground plant growth is curtailed more than photosynthesis, causing leaves surplus carbohydrates. Each above phenomena provide sink for carbohydrates, thereby preventing feedback inhibition perpetuating influx C. Because incur little cost source plant, need benefit beyond removal