Native submerged macrophyte distribution in seasonally-flowing, south-western Australian streams in relation to stream condition

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• 作者：Robyn L. Paice ; Jane M. Chambers ; Belinda J. Robson
• 关键词：Aquatic plants ; Freshwater invertebrates ; Stream degradation ; Temporary rivers
• 刊名：Aquatic Sciences
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：79
• 期：1
• 页码：171-185
• 全文大小：
• 刊物类别：Biomedical and Life Sciences
• 刊物主题：Freshwater & Marine Ecology; Marine & Freshwater Sciences; Oceanography; Ecology; Life Sciences, general;
• 出版者：Springer International Publishing
• ISSN：1420-9055
• 卷排序：79

文摘

Submerged macrophytes are important structural and biological components of many lowland streams with potential to support ecosystem processes in degraded streams, provided that growth is not excessive. In a low-gradient agricultural landscape, a survey was used to explore associations between submerged macrophyte growth, biodiversity and variables assessing stream condition in seasonally-flowing streams. These variables were sampled across fifty-three reaches on seven adjacent streams in the mediterranean climate region of south-western Australia. Native submerged macrophytes were present in 43 % of sampled reaches, forming two distinct macrophyte assemblages dominated either by Potamogeton spp. together with Otteliaovalifolia, or by Cycnogeton spp. The Potamogeton/Ottelia assemblage was present in degraded reaches with higher light availability and deposition of fine sediments, but did not show excessive growth, even under nutrient-enriched conditions. Conversely, Cycnogeton spp. were associated with shaded conditions and greater flow. Reaches with macrophytes present had significantly higher macroinvertebrate abundance and family richness than those without, although rarefied family richness was similar among reaches with and without submerged macrophytes. The more structurally complex Potamogeton/Ottelia assemblage supported a greater abundance of grazers, shredders and predators than the simpler Cycnogeton spp. In degraded agricultural streams, remnant and colonising populations of submerged macrophytes may compensate for loss of riparian-derived habitat and resources for macroinvertebrates, and thus the food supply for predatory species.