The occurrence of the three principal reserve carbohydrates, starch, fructan and sucrose, is documented in 20 native British species over four seasons. Species containing two of the reserve carbohydrates in different combinations were present in each of three common habitats.
Sucrose reserves Undergo considerable depletion after winter. Starch depletion also occurs in many though not all species. In contrast, fructan is stored in high concentrations which are not subject to depletion. This indicates the fructan has functions other than as a source of consumable carbohydrate, one of which may be as an osmotic regulator.
Fructan is associated with relatively restricted phenologies associated with early-season, low-temperature growth. In contrast, the Storage of starch or sucrose as a principal reserve carbohydrate is associated with the broadest variation in phenological patterns. There is, however, no indication that fructan has a unique or specific-role in low temperature tolerance as similar attributes are shown to be present in a number of non-fructan species.
In relation to herbivore nutrition, each type of carbohydrate is made relatively unavailable either in space (starch and fructan) or in time (sucrose). The consequences of these various characteristics are considered in relation to plant evolution and Survival.