Litterfall Dynamics and Element Use Efficiency in a Kansas Gallery Forest

Abstract

Transfers of biomass and 10 elements in the litterfall of a deciduous gallery forest were studied.on the Konza Prairie Research Natural Area in eastern Kansas. Mean annual litterfall was 694 g m-2year-1 and was composed of 70% leaves, 19% woody litter and 11% reproductive tissues. Importance Values were not useful in accurately predicting the relative contributions of individual species to total litterfall. Leaf litter contained more Ca, Mg, K, Na, Mn, Cu, Fe, Zn, P and N than woody litter and reproductive tissues combined. The allocation of biomass to a specific tissue type and/or species was often very different from the corresponding allocation of elements, indicating that biomass/element allocation patterns are not inextricably linked at the individual or community level. Leaf litterfall occurred predominantly in the autumn (88%), but the majority of element transfers from woody litter and reproductive tissues took place during the remainder of the year, thus partially offsetting the extreme pulsed deposition patterns dictated by leaf litterfall alone. Efficiencies of Ca and P use were extremely low, whereas N use efficiency was moderate compared to other forest types. This, coupled with additional information on autumnal element resorption and demand:availability quotients, suggested that N may be the most limiting element in many gallery forest ecosystems. Within the Konza gallery forest, subdominant species were much less efficient at using Mg, K, P and N than the dominant species.