Do experimental pH increases alter the structure and function of a lowland tropical stream?
Do experimental pH increases alter the structure and function of a lowland tropical stream?
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DOI：
10.1002/ecs2.4097
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发表时间：
2022-07-01
期刊：
影响因子：
2.7
通讯作者：
Ardon，Marcelo
中科院分区：
文献类型：
--
作者：
Marzolf，Nicholas S.;Baca，Dominic M.;Ardon，Marcelo
干扰可以改变生态系统的结构和功能。在河流生态系统中，短期、中期和长期重复间隔的排放和物理化学变化会影响食物网和生态系统过程。在本文中，我们比较了流在拉塞尔瓦生物站，哥斯达黎加，在整个流网络的情景酸化频率变化很大，由于缓冲的碳酸氢盐丰富的流域间地下水的输入的pH值制度。为了研究酸化对生态系统结构和功能的影响，我们通过实验增加了一个源头流的缓冲能力，并将其与一个无缓冲的上游河段进行了比较。我们将这些河段与第二条源头河流的自然缓冲和非缓冲河段进行了比较。我们量化了生态系统的结构（大型无脊椎动物组合的落叶和粗木质残体）和功能的反应（落叶和粗木质残体的分解率，和增长率的重点昆虫类群[双翅目：摇蚊科]）。非度量多维尺度和相似性分析表明，大型无脊椎动物组合相对同质的四个研究达到，虽然自然缓冲达到是最不相似的。生态系统的功能，以摇蚊的增长率，是更大的自然缓冲区达到，而分解率并没有不同的四个达到。我们的研究结果表明，生物组合是适应pH值制度的经常酸化流达到。我们的实验通知结构和功能的影响，在短时间尺度上的流，经历中度酸化，但较大幅度的酸化事件响应水文气候变化，预测气候变化情景下，可能会引起更强的响应流。
Disturbances can alter the structure and function of ecosystems. In stream ecosystems, changes in discharge and physicochemistry at short, intermediate, and long recurrence intervals can affect food webs and ecosystem processes. In this paper, we compare pH regimes in streams at La Selva Biological Station, Costa Rica, where episodic acidification frequency across the stream network varies widely due to buffering from inputs of bicarbonate‐rich interbasin groundwater. To examine the effects of acidification on ecosystem structure and function, we experimentally increased the buffering capacity of a headwater stream reach and compared it to an unbuffered upstream reach. We compared these reaches to a naturally buffered and unbuffered reaches of a second headwater stream. We quantified ecosystem structural (macroinvertebrate assemblages on leaf litter and coarse woody debris) and functional responses (leaf litter and coarse woody debris decomposition rates, and growth rates of a focal insect taxon [Diptera: Chironomidae]). Non‐metric multidimensional scaling and analysis of similarity revealed that macroinvertebrate assemblages were relatively homogenous across the four study reaches, although the naturally buffered reach was the most dissimilar. Ecosystem function, as measured by chironomid growth rates, was greater in the naturally buffered reach, while decomposition rates did not differ across the four reaches. Our results indicate that biological assemblages are adapted to pH regimes of frequently acidified stream reaches. Our experiment informs the effects on structure and function at short time scales in streams that experience moderate acidification, but larger magnitude acidification events in response to hydroclimatic change, as projected under climate change scenarios, may induce stronger responses in streams.