The community composition, distribution, and nutrient status of epilithic periphyton at five rocky littoral zone sites in Lake Malawi, Africa
The community composition, distribution, and nutrient status of epilithic periphyton at five rocky littoral zone sites in Lake Malawi, Africa
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DOI：
10.1016/s0380-1330(03)70547-4
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发表时间：
2003-01-01
影响因子：
2.2
通讯作者：
Bootsma, HA
中科院分区：
文献类型：
--
作者：
Higgins, SN;Kling, HJ;Bootsma, HA
马拉维湖的附生藻类以异晶蓝藻/蓝藻和含有能够固氮的内共生体的硅藻为主，尽管在一些地方，例如沉积物和营养物质负荷的影响，使藻类群落结构转向硅藻和绿藻的优势。总体而言，重氮营养(能够固定N-2)的Calothrix spp.在本研究范围内的几乎所有地点/深度，都以滨海附生植物群落为主。伴生异形囊的生物量随着深度的增加呈下降趋势，不同地点间差异不大。稻纵卷叶蝉内的重氮型内共生菌是所有地点/深处藻类群落的一个共同特征，尽管以前在马拉维湖的文献中没有报道过。虽然使用化学计量比C：N：P来确定自然发生的附生植物群落的营养状况受到藻类基质的碎屑和非生物部分的混淆，但重氮营养藻类的优势表明，岩石海岸带是N受限的系统。
The epilithic periphyton of Lake Malawi is dominated by heterocystous cyanoprokaryotes (blue-green algae/cyanophytes) and diatoms containing endosymbionts capable of nitrogen fixation, though in some locations impacts such as sediment and nutrient loading have shifted the algal community structure towards dominance by diatoms and chlorophytes. Overall, diazotrophic (capable of N-2 fixation) Calothrix spp. dominated the littoral periphyton communities at almost all sites/depths located within this study. The biovolume of associated heterocysts tended to decline with depth and was similar between sites. Diazotrophic endosymbionts within Rhopalodia spp. were a common feature of the algal community at all sites/depths, although they have not previously been reported in the literature for Lake Malawi. While the use of stoichiometric C:N:P ratios to determine the nutrient status of naturally-occurring periphyton communities was confounded by detrital and non-living portions of the algal matrix, the dominance of diazotrophic algae suggests that the rocky littoral zones are N-limited systems.