Thermal reaction norms of a subtropical and a tropical species of Diaphanosoma (cladocera) explain their distribution
Thermal reaction norms of a subtropical and a tropical species of Diaphanosoma (cladocera) explain their distribution
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亚热带和热带Diaphanosoma（枝角类）物种的热反应规范解释了它们的分布
DOI：
10.1002/lno.10766
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发表时间：
2018-05-01
影响因子：
4.5
通讯作者：
Dumont, Henri J.
中科院分区：
文献类型：
--
作者：
Pajk, Franja;Zhang, Jiexiang;Dumont, Henri J.
物种分布的边界通常与气候的各个方面有关，并被竞争性的相互作用所改变。在热带地区，海鞘藻属是枝角类中最多样的属。中国地区分布较广，热带地区分布较广，仅分布于中国南岸海岛。在其分布的北端，最冷月份的平均温度为15℃。为了确定它们的热性能曲线(TPC)是否能解释它们的分布，并估计它们的TPC遗传变异的程度和方式，我们在生命表实验中研究了温度(10-40℃)对杜鹃和石杉16个种群无性系生活史特征的影响。结果表明，两种动物的最适温度(∼33℃)、临界最低温度( = 10-15℃)和最高温度(CTmax = 39-40℃)均高于温带枝角类。根据温度分布随纬度变化的预测，石杉无性系的TPC较窄，比杜鹃无性系的TPC高。在两个物种中都存在显著水平的TPC遗传变异。在15℃以上的所有温度下，金边石杉的适合度均高于杜鹃，但在15℃及以下时，杜鹃的适合度较高。在15°C及以下的负r，再加上与更冷适应的杜氏菌的竞争，排除了来自大陆中国的D·exisum。随着温度升高改变生物相互作用的平衡，相互作用物种的TPC可能是预测未来物种分布的基础。
Species distribution boundaries are often associated with aspects of climate and modified by competitive interactions. In the tropical region, Diaphanosoma is the most diverse genus of Cladocera. Diaphanosoma dubium is widely distributed in China, whereas the tropical Diaphanosoma excisum is restricted to the islands off the south China coast. The mean temperature of the coldest month at the northern limit of its distribution is 15°C. We studied the effect of temperature (10–40°C) on life history traits of clones from 16 populations of D. dubium and D. excisum in life‐table experiments in order to determine if their thermal performance curves (TPCs) explain their distribution and to estimate the extent and mode of genetic variation in their TPCs. Our results show that both species have higher optimum temperatures (To ∼ 33°C), critical thermal minimum (CTmin = 10–15°C), and maximum (CTmax = 39–40°C) than temperate cladocerans. Clones of D. excisum had narrower TPCs and higher To than D. dubium clones, in accordance with predictions based on changes of temperature distributions with latitude. Significant levels of genetic variation in TPCs were present in both species. D. excisum had higher fitness than D. dubium at all temperatures above 15°C. However, at 15°C and below, D. dubium fitness was higher. Negative r at 15°C and below in combination with competition with the more cold‐adapted D. dubium exclude D. excisum from mainland China. TPCs of interacting species may be the basis of predicting future species distributions as temperature increases change the balance of biotic interactions.