Growth and reproduction ofRumex maritimusandChenopodium rubrumunder different waterlogging regimes

Abstract

The influence of different waterlogging treatments on above-gro und development and subsequent flowering and seed production of Chenopodium rubrum L. and Rumex maritimus L. was studied in a greenhou se experiment.C. rubrum, a typical occupant of low sa ndy beaches at tim es when floods have subsided, appeared to be suppressed by a ll waterloggin g regimes. R. maritimus, an inh abitor of wet mud flats of old river beds, was found to be quite tolerant to waterloggi ng conditions; early waterlogging, during the rose tte stage, led to an increase in dry weight and seed production in some ca es. In genera l, seed production cha nged more than biomass as a result of waterlogging; responses greatly depend on regimes. Intermittent waterlogging genera ll y caused more dama ge than did continuou s waterlogging, especia ll y in the case of C. rubrum . Even R. maritimus produced less seeds und er conditions of intermittent waterlogging. The res ults demon strate that adaptations to , and dama ge from , flooding grea tly depend on floodin g regim es which vary substantially in the field situation .

Physiological Ecology of Riverside Species: Adaptive Responses of Plants to Submergence

“…The use of model species that serve as indicators for larger groups of plants allows an extrapolation of results to the level of plant communities. Later screening of adaptation reactions in other than model species can then be expected to validate the results obtained Blom, 1988;Blome/ «/., 1990;Blom, Voesenek and Van der Sman, 1993). During the relatively short periods of water deprivation between successive floods, plants of these species (e.g., Chenopodium rubrum) very quickly complete their life cycle and produce seeds that will survive the next flood (Van der Sman et al, 1991.…”

Adaptations to flooding in plants from river areas

“…4) showed remarkable differences between the two species. Both species were strongly affected by waterlogging applied at various stages of the life cycle (van der Sman et al, 1988). In C. rubrum, there was a tendency towards reduction of seed output, while in R. maritimus there was an increase in seed output compared with non-waterlogged plants.…”

“…How ever, the tap roots of these plants supply the sugar with which plants survive long-lasting floods ( Laan, 1990 ). Flowering has been proven to be delayed in response to flooding (van der Sman et al, 1988), which often results in re duced seed production. In general, flood-tolerant species secure their repro duction in spite of the unfavourable environmental conditions caused by flooding.…”

“…The severity of the flooding can range from water logging of the soil to submergence of the whole plant. While the responses of plants in waterlogged soils may differ from those of plants facing submer gence, both conditions greatly influence the physiology, morphology and pop ulation biology of the plants (van der Sman et al, 1988;Blom, 1990;Laan, 1990;Voesenek, 1990). As many river forelands are characterized by differ ences in elevation and thus to the extent to which they are inundated, plant zonation caused by these differences can often be distinguished.…”

The realism of models in plant demography

“…Fluctuating anaer obic conditions resulting from flooding strongly influence growth in plants (Voesenek & Blom 1987;Talbot et al 1987;Justin & Armstrong 1987;Voesenek et al 1989). Waterlogging induces different responses in seed production (Van der Sman et al 1988); Rumex maritimus appeared to be tolerant to flooding, and seed production increased under some conditions, whereas in Chenopodium rubrum seed production decreased significantly.…”