Temperature-dependent competition between juvenile salmonids in small streams
Temperature-dependent competition between juvenile salmonids in small streams
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小溪中鲑鱼幼鱼之间依赖温度的竞争
DOI：
10.1111/fwb.13325
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发表时间：
2019
影响因子：
2.7
通讯作者：
K. & Koizumi
中科院分区：
文献类型：
--
作者：
Watz;J.;Ohtsuki;Y.;Nagatsuka;K.;Hasegawa;K. & Koizumi
生物相互作用影响物种的分布，而影响这些相互作用的环境因素可以在模拟环境变化引起的范围变化时发挥关键作用。在野外试验中，我们使用围隔，研究了热生境对幼多莉VardenSalvelinus malma和白色斑点红点鲑Salvelinus leucomaenis种内与种间竞争的影响，这是通过在夏季期间在异域和同域处理中的特定生长率的差异来测量的。以前的实验室实验表明，温度依赖的竞争能力作为溪流鱼类空间分离的主要驱动力的重要性，结果不一，到目前为止，还没有研究证实它在自然溪流中的存在。在自然条件下，两个物种在同域分布的地区，多莉瓦登占主导地位的春季喂养支流（冷，稳定的热制度），而这两个物种往往共存于非春季喂养的支流（温暖，不稳定的热制度）。外壳（charr密度= 6每平方米）被放置在非春季饲养（10-14°C）和春季饲养（7-8°C）支流。在非春季饲养支流的围栏中，多莉瓦登每天在异地生长0.81%，（-0.33%每天）在同域性，而增长率是相似的，在异域性和同域性在春季喂养的支流（0.68和0.58%每天）。白色斑点红点鲑在两种热生境中同域分布比异地分布生长得更好。在非春季饲养的支流中，它们每天分别增长0.17%和0.79%，在春季饲养的支流中，每天分别增长0.46%和0.75%。因此，白色斑点红点鲑种间竞争对多莉瓦登的负面影响取决于热生境。然而，没有强有力的证据表明温度依赖的影响，种内和种间竞争的白色斑点charr growth.Multiple因素可能会塑造物种分布格局，我们表明，温度可能介导的竞争结果，从而在溪流鱼类共存。温度的这些影响将是重要的，纳入机械和动态物种分布模型。
Biotic interactions affect species distributions, and environmental factors that influence these interactions can play a key role when range shifts in response to environmental change are modelled.In a field experiment using enclosures, we studied the effects of the thermal habitat on intra‐ versus inter‐specific competition of juvenile Dolly VardenSalvelinus malmaand white‐spotted charrSalvelinus leucomaenis, as measured by differences in specific growth rates during summer in allopatric and sympatric treatments. Previous laboratory experiments have shown mixed results regarding the importance of temperature‐dependent competitive abilities as a main driver for spatial segregation in stream fishes, and no study so far has confirmed its existence in natural streams.Under natural conditions in areas where the two species occur in sympatry, Dolly Varden dominate spring‐fed tributaries (cold, stable thermal regime), whereas both species often coexist in non‐spring‐fed tributaries (warm, unstable thermal regime). Enclosures (charr density = 6 per m2) were placed in non‐spring‐fed (10–14°C) and spring‐fed (7–8°C) tributaries.In enclosures placed in non‐spring‐fed tributaries, Dolly Varden grew 0.81% per day in allopatry and had negative growth (−0.33% per day) in sympatry, whereas growth rates were similar in allopatry and sympatry in spring‐fed tributaries (0.68 and 0.58% per day). White‐spotted charr grew better in sympatry than in allopatry in both thermal habitats. In non‐spring‐fed tributaries, they grew 0.17 and 0.79% per day and in spring‐fed tributaries 0.46 and 0.75% per day in allopatry and sympatry, respectively.The negative effect of inter‐specific competition from white‐spotted charr on Dolly Varden thus depended on the thermal habitat. However, there was no strong evidence of a temperature‐dependent effect of intra‐ and inter‐specific competition on white‐spotted charr growth.Multiple factors may shape species distribution patterns, and we show that temperature may mediate competitive outcomes and thus coexistence in stream fish. These effects of temperature will be important to incorporate into mechanistic and dynamic species distribution models.