英语翻译Light limiting thresholds for submerged aquatic vegetation in a blackwater riverDean R.DobberfuhlSt.Johns River Water Management District,4049 Reid Street,Palatka,FL 32178,United StatesReceived 19 January 2006; received in revised form 16

英语翻译Light limiting thresholds for submerged aquatic vegetation in a blackwater riverDean R.DobberfuhlSt.Johns River Water Management District,4049 Reid Street,Palatka,FL 32178,United StatesReceived 19 January 2006; received in revised form 16
英语翻译
Light limiting thresholds for submerged aquatic vegetation in a blackwater river
Dean R.Dobberfuhl
St.Johns River Water Management District,4049 Reid Street,Palatka,FL 32178,United States
Received 19 January 2006; received in revised form 16 November 2006; accepted 3 January 2007
Abstract
Field-based monitoring data were used to estimate the limiting light threshold for Vallisneria americana,the dominant species,in the St.Johns River,Florida.There was a considerable range of threshold estimates (0.5–35% of surface light) among individual observations.Light threshold calculations were divided into low- and high-salinity groups of sites.The field-based mean threshold for 1998–2004 was 9% for low-salinity (0.5 ppt annual mean) had a higher mean light threshold of 14%.A separate analysis of the freshwater Crescent Lake suggested a light threshold of 9%.Increased epiphyte biomass during the drought may have accounted for the majority of the higher light requirements in the freshwater reach of the river.Light requirement values in this study were similar to other studies focusing on V.americana.
# 2007 Elsevier B.V.All rights reserved.
Keywords:Vallisneria americana; Minimum light threshold; Salinity effect; Epiphyte burden; Drought

英语翻译Light limiting thresholds for submerged aquatic vegetation in a blackwater riverDean R.DobberfuhlSt.Johns River Water Management District,4049 Reid Street,Palatka,FL 32178,United StatesReceived 19 January 2006; received in revised form 16
光限制阈值的沉水植物在黑水河流
迪恩河Dobberfuhl
圣约翰斯河水管理区,4049里德街,帕拉特卡,佛罗里达州32178,美国
二零零六年一月十九日收到的,在修订的形式收到的06年11月16日,接受2007年1月3日
摘要
基于实地的监测数据来估计的限制为美洲苦草,优势种在圣约翰河,佛罗里达州,光阈值.有一个阈值估计在个别意见（0.5-35％的表面光）相当广泛.光阈值的计算分为低和高盐度网站群.该油田为基础的1998-2004年的平均阈值是9的低矿化度“（