Department of Information and Computer Sciences, Faculty of Sciences, Nara Women's University, Kita-Uoya Nishimachi, Nara 630-8506, Japan.
J Theor Biol. 2013 Feb 21;319:122-33. doi: 10.1016/j.jtbi.2012.11.016. Epub 2012 Dec 3.
Shallow lakes and ponds are often characterised either by clear water with abundant submerged macrophytes or by turbid water with abundant phytoplankton. Blooms of toxic filamentous blue-green algae (cyanobacteria) often dominate the phytoplankton community in eutrophic lakes, which threatens ecological functions and biodiversity of freshwater ecosystems. We studied a simple lake model in order to evaluate individual and combined suppressive effects of rooted submerged and rooted floating-leaved macrophytes on algal blooms. Floating-leaved plants are superior competitors for light, whereas submerged plants absorb and reduce available phosphorus in a water column that rooted floating-leaved plants exploit to a lesser extent. We found that mixed vegetation that includes both submerged and floating-leaved plants is more resistant than vegetation comprised by a single plant type to algal invasion triggered by phosphorus loading. In addition, competitive exclusion of submerged plants by floating-leaved plants may promote an algal bloom. These predictions were confirmed by the decision tree analysis of field data from 35 irrigation ponds in Hyogo Prefecture, Japan.
浅水湖泊和池塘的特征通常是水清澈，有大量的沉水植物，或者水浑浊，有大量的浮游植物。富营养化湖泊中，有毒丝状蓝藻（蓝细菌）的大量繁殖常常会占据浮游植物群落的主导地位，这会威胁到淡水生态系统的生态功能和生物多样性。我们研究了一个简单的湖泊模型，以评估有根沉水植物和有根浮叶植物对藻类水华的单独和联合抑制作用。浮叶植物在争夺阳光方面具有优势，而沉水植物则会吸收和减少水柱中可用的磷，而浮叶植物对磷的利用程度则较低。我们发现，与仅由单一植物类型组成的植被相比，包括沉水植物和浮叶植物在内的混合植被对磷负荷引发的藻类入侵具有更强的抵抗力。此外，浮叶植物对沉水植物的竞争排斥可能会促进藻类水华的发生。这些预测得到了来自日本兵库县 35 个灌溉池塘的实地数据的决策树分析的证实。
