Seasonal dynamics of macroalgal communities of the northern Florida reef tract
Seasonal dynamics of macroalgal communities of the northern Florida reef tract
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DOI：
10.1515/bot.2000.033
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发表时间：
2000-07-01
期刊：
影响因子：
2.2
通讯作者：
Biber, P
中科院分区：
文献类型：
--
作者：
Lirman, D;Biber, P
由于自然和人类的干扰，世界各地的珊瑚群落正在严重退化，许多珊瑚礁系统的活珊瑚覆盖面已经因大型藻类的增加而大幅度减少。丰饶。在这里，我们记录了北方佛罗里达珊瑚礁区的大型藻类群落的季节动态，为长期研究珊瑚藻竞争提供了一个基线，在该地区。无论是大型藻类生物量和珊瑚礁覆盖率呈上升趋势，从1月至7月，当光照和温度条件有利于生长。覆盖率最高（56.7%）出现在7月，最低水平出现在12月（25.8%）。在藻类覆盖的高峰期，许多珊瑚完全被密集的藻类覆盖。两个属，Halimeda和Dictyota，占总藻类生物量的最大比例（77-99%）。在夏季，网地藻属（Dictyota spp.）占礁底面积的40%，干生物量达20 g.m（-2）。此外，两个物种，Stypopodium zonale和Trichogloea requienii，显示了显着的盛开在1998年4月，覆盖了显着的比例的底部（高达25%）在近岸珊瑚礁。在佛罗里达珊瑚礁上表现出快速空间垄断的物种，如网地藻属。和Stypopodium zonale，也显示了快速增长的微观和现场生长的研究。没有发现之间的相关性，鱼类食草动物丰度和藻类生物量或百分比覆盖，表明目前的食草动物种群的丰度和组成是不足以防止空间垄断和珊瑚过度生长的藻类，如Dictyota种。和Halimeda spp.只有持续的监测工作才能确定藻类群落的季节性动态是否会导致北方佛罗里达珊瑚礁区珊瑚数量的减少。
Coral communities worldwide are undergoing intense degradation in response to natural and human disturbances, and many reef systems have already experienced significant declines in live coral cover associated with an increase in macroalgal. abundance. Here, we document the seasonal dynamics of the macroalgal communities of the Northern Florida Reef Tract, providing a baseline for long-term studies of coral-algal competition in the area.Both macroalgal biomass and percent cover on reefs showed an increasing trend from January to July, when both light and temperature conditions were favorable for growth. Maximum percent cover (56.7%) was found in July and minimum levels in December (25.8%). During these peaks in algal cover, many corals were completely covered by dense mats of algae. Two genera, Halimeda and Dictyota, represented the largest proportion (77-99%) of the total algal biomass. In the summer, Dictyota spp. dominated the algal community, occupying up to 40% of the reef bottom with a dry biomass of up to 20 g.m(-2). In addition, two species, Stypopodium zonale and Trichogloea requienii, showed a significant bloom in April 1998, covering a significant percentage of the bottom (up to 25%) at an inshore reef. Species that exhibited rapid space monopolization on Florida reefs, such as Dictyota spp. and Stypopodium zonale, also showed rapid growth in microcosm and field growth studies.No correlations were found between fish grazer abundance and algal biomass or percent cover, indicating that present grazer population abundance and composition are not adequate to prevent space monopolization and coral overgrowth by algae such as Dictyota spp. and Halimeda spp. Only a continued monitoring effort will determine whether the seasonal dynamics of the algal community may result in the decline of coral populations in the Northern Florida Reef Tract.