Effects of pollen leaching and microbial degradation on organic carbon and nutrient availability in lake water
Effects of pollen leaching and microbial degradation on organic carbon and nutrient availability in lake water
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DOI：
10.1007/s00027-011-0198-3
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发表时间：
2011
期刊：
影响因子：
2.4
通讯作者：
Stefan Rösel;Anna Rychła;C. Wurzbacher;H. Grossart
中科院分区：
文献类型：
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作者：
Stefan Rösel;Anna Rychła;C. Wurzbacher;H. Grossart
营养盐跨陆-水边界的通量及其与湖泊营养盐循环的整合是当前水生生物研究的一个重要课题。尽管花粉是微生物生长的良好基质，但它作为湖泊中有机物的陆地来源一直被忽视。在实验室实验中，我们培养的花粉粒樟子松在不同的奖杯和pH值的湖泊水体中，以估计花粉输入及其随后的微生物降解对营养动态的影响。在这一situexperiment中，我们测量了有机碳，磷和氮的浓度在周围的水以及微生物动力学（细菌和真菌孢子囊）在良好的控制条件。除了浸出，花粉的化学和微生物分解是最强的第一周内孵化。这导致了环境水中可溶性活性磷和总溶解氮的显著增加（培养5天后分别达到0.04和1.5 mg L−1）。与此同时，花粉粒迅速定植异养细菌和水生真菌。花粉的淋溶和微生物降解分别占有机C、N和P的≥ 80%、≥ 40%和≥50%，并且在所研究的湖泊水样中没有显著差异。因此，花粉在短时间内将大量生物可利用的陆地有机物和营养物质引入地表沃茨。通过对贫营养湖泊Stechlin磷输入量的粗略计算，表明花粉在温带湖泊营养循环中起着重要的生态作用。这需要在水生生态学中进一步关注。
Nutrient fluxes across terrestrial-aquatic boundaries and their subsequent integration into lake nutrient cycles are currently a major topic of aquatic research. Although pollen represents a good substrate for microorganisms, it has been neglected as a terrestrial source of organic matter in lakes. In laboratory experiments, we incubated pollen grains ofPinus sylvestrisin water of lakes with different trophy and pH to estimate effects of pollen input and its subsequent microbial degradation on nutrient dynamics. In thisex situexperiment, we measured concentrations of organic carbon, phosphorus and nitrogen in the surrounding water as well as microbial dynamics (bacteria and fungal sporangia) at well-controlled conditions. Besides leaching, chemical and microbial decomposition of pollen was strongest within the first week of incubation. This led to a marked increase of soluble reactive phosphorus and total dissolved nitrogen (up to 0.04 and 1.5 mg L−1, respectively, after 5 days of incubation) in the ambient water. In parallel, pollen grains were rapidly colonized by heterotrophic bacteria and aquatic fungi. Leaching and microbial degradation of pollen accounted for ≥80, ≥40, ≥50% for organic C, N and P, respectively, and did not significantly differ among water samples from the studied lakes. Thus, pollen introduces high amounts of bio-available terrestrial organic matter and nutrients into surface waters within a short time. A rough calculation on P input into oligotrophic Lake Stechlin indicates that pollen plays an important ecological role in nutrient cycling of temperate lakes. This requires further attention in aquatic ecology.