Roles of parasitic fungi in aquatic food webs: a theoretical approach
Roles of parasitic fungi in aquatic food webs: a theoretical approach
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DOI：
10.1111/j.1365-2427.2010.02562.x
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发表时间：
2011-06-01
影响因子：
2.7
通讯作者：
Kagami, Maiko
中科院分区：
文献类型：
--
作者：
Miki, Takeshi;Takimoto, Gaku;Kagami, Maiko
P>1。寄生虫在生态系统中无处不在，但人们对它们在物质转移中的作用知之甚少。淡水生态系统中的真菌寄生虫对小型异养真核生物非常重要，并消耗大量抵抗浮游动物放牧的浮游植物。2．为了评估它们对生态系统水平的影响，我们开发了一个简单的食物网模型，其中包含小型和大型浮游植物之间对营养物质的竞争、浮游动物对小型浮游植物的放牧、真菌对大型浮游植物的寄生，并包括新发现的从真菌游动孢子到浮游动物的营养联系（F-Z联系）。3。我们的模型证明了真菌和浮游动物之间可能存在间接互利共生，其中真菌寄生通过减少不可食用的大型浮游植物的生物量来增加浮游动物的产量。与之前的短期实验中 F-Z 链接可能有益于浮游动物的预期相反，由于间接互利共生的负面影响，F-Z 链接的存在可以减少从浮游植物到浮游动物的物质转移。该模型表明，真菌在宿主组织上的高生长效率及其对浮游动物的高营养状态对于F-Z链接提高浮游动物产量至关重要。4．该模型还表明，通过 F-Z 连接向浮游动物转移物质的贡献随着养分可用性的增加而增加。我们的结果表明，寄生真菌可能是物质转移的关键参与者，特别是在富营养化生态系统中。
P>1. Parasites are ubiquitous in ecosystems, but their roles in material transfer are poorly understood. Fungal parasites in freshwater ecosystems are of major importance to small heterotrophic eukaryotes and consume large phytoplankton that are resistant to zooplankton grazing.2. To evaluate their ecosystem-level effects, we developed a simple food web model that incorporates competition between small and large phytoplankton for nutrients, zooplankton grazing on small phytoplankton, fungal parasitism on large phytoplankton and includes a newly discovered trophic link from fungal zoospores to zooplankton (F-Z link).3. Our model demonstrates the likely occurrence of an indirect mutualism between fungi and zooplankton, in which fungal parasitism increases zooplankton production by reducing the biomass of inedible large phytoplankton. Contradicting the expectation from a previous short-term experiment that the F-Z link may benefit zooplankton, the presence of the F-Z link can reduce material transfer from phytoplankton to zooplankton because of the negative effect of the indirect mutualism. The model indicates that high growth efficiency of fungi on host tissue and their high nutrient status for zooplankton are crucial for the F-Z link to increase zooplankton production.4. The model also indicates that the contribution of material transfer via F-Z link to zooplankton increases with nutrient availability. Our results suggest that parasitic fungi may be a key player in material transfer, especially in eutrophic ecosystems.