Applications of organ-specific growth models; modelling of resource translocation and the role of emergent aquatic plants in element cycles

概要

論文の詳細を見る
This paper presents and reviews the conceptual structure of several recently developed organ-specific growth models and discusses their applications, with particular emphasis on material translocation between above- and belowground systems and the role of aquatic plants in element cycles. The efficiency of the element cycling process in wetlands is closely related to the proportional biomass allocation to above- and belowground organs. Therefore, the framework of most macrophyte productivity models is usually similar, with a mass-balance approach consisting of gross production, respiration and mortality losses, and the translocation between organs. The paper delineates how these growth models are linked with decomposition models to evaluate the annual cycle of elements. The model formulating procedure and the material budget and translocation processes of two perennial emergent species, Typha angustifolia and Zizania latifolia, and the coupling of the validated partitioned growth model with the modules for decomposition based on a modified decomposition coefficient, are further discussed. Furthermore, the effect of differing water depth on the rhizomatous sedge species Eleocharis sphacelata was studied based on its responsive adaptation by apportioning additional resources to shoots.The analysis of latitudinal effects based on the modelling results for Typha showed that the annual gross production was larger in lower latitudes; however, the higher temperature therein resulted in larger respiration and mortality losses, which balanced the annual gross production in the equivalent stage. The annual translocation of resources to rhizomes was also larger in lower latitudes. Due to the very slow anaerobic decomposition in water, the amount of litter in the anaerobic substrate accumulated continuously at steady rates.Management application to determine harvesting timing to remove biomass is discussed for Phragmites australis and Typha angustifolia based on the elucidations of modelling results on the translocation of resources for spring growth of new shoots and the subsequent exhaustion of rhizome stocks. The model results of E. sphacelata depicted that gross production of the plant stand increases with water depth until about 0.5 m, as water availability supports plant production and survival. Thereafter, the maximum production decreases rapidly with increasing water depth because the shoots are increasingly inundated by water, thus restricting the shoot surface area that is capable of photosynthetic production.These applications highlight the efficiency of employing modelling as a tool to develop management schemes of aquatic macrophytes as well as to obtain insight into the mechanisms involved, as an alternative to cumbersome empirical approaches, such as field observations or pilot investigations. (C) 2008 Elsevier B.V. All rights reserved.

Applications of organ-specific growth models; modelling of resource translocation and the role of emergent aquatic plants in element cycles

スポンサーリンク

概要

論文 | ランダム

スポンサーリンク