自然保护与休闲部保护·守护·共享
自然保护与休闲部
目录半永久性蓄水池
This group encompasses aquatic and shoreline vegetation of both beaver ponds and persistent man-made impoundments (e.g., millponds) along streams in all regions of Virginia. Compared to communities in the Floodplain Ponds and Pools group, semipermanent impoundments are more subject to unpredictable disturbances from flooding, beaver activities, irregular water fluctuations, and breaching of dams. Over time, or more rapidly when drained, these wetlands tend to fill with sediment and undergo invasion by emergent and woody vegetation. Community composition varies greatly with geographic region, disturbance regimes, substrate and water depth. Emergent, non-tidal marshes are characteristic of abandoned but persistent beaver ponds. Dominant species of such marshes in the Coastal Plain include smartweeds (Persicaria spp.), pickerelweed (Pontederia cordata var. cordata), arrow-arum (Peltandra virginica), common rush (Juncus effusus), three-way sedge (Dulichium arundinaceum var. arundinaceum), tussock sedge (Carex stricta), spikerushes (Eleocharis spp.), coastal mannagrass (Glyceria obtusa), Virginia marsh St. John's-wort (Triadenum virginicum), and swamp rose-mallow (Hibiscus moscheutos). In the Piedmont and mountains, American bur-reed (Sparganium americanum), arrow-arum (Peltandra virginica), sedges (Carex spp.), lizard's-tail (Saururus cernuus), common water-purslane (Ludwigia palustris), alternate-leaved seedbox (Ludwigia alternifolia), common cattail (Typha latifolia), southern water-plantain (Alisma subcordatum), woolgrass (Scirpus cyperinus), woodland bulrush (Scirpus expansus), and rice cutgrass (Leersia oryzoides) are more characteristic.
深水蓄水池中以浮水和沉水植物为典型，包括滨海平原的白睡莲（ Nymphaea odorata ssp. odorata ）和狸藻（ Utricularia spp.），以及常见的水螅（ Nuphar advena ）、莼菜（ Brasenia schreberi ）、水草（ Potamogeton spp.）、大型水星草等。 （ Callitricheheterophyllavar.heterophylla ）和浮萍（ Lemnaspp .）遍布全州。稀有的泥炭或沙质沿海平原池塘具有丰富的渗流输入，支持着国家稀有物种，如水芦苇 ( Schoenoplectus subterminalis )、罗宾斯荸荠 ( Eleocharis robbinsii )、马尾荸荠 ( Eleocharis equisetoides )、紫狸藻 ( Utricularia purpurea ) 和大浮心 ( Nymphoides aquatica )。
参考文献：Coulling ( 2002 )、McCoy 和 Fleming ( 2000 )、Walton等人。（ 2001 ）。
© DCR-DNH，加里·P·弗莱明。
