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The phenological optimum in space and time

空间和时间上的最佳物候期

基本信息

批准号：
NE/P011802/1
负责人：
Albert Phillimore
金额：
$ 66.54万
依托单位：
University of Edinburgh
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2017
资助国家：
英国
起止时间：
2017 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=NE%2FP011802%2F1
关键词：
phenological optimum space time

项目摘要

For the many animals and plants that live in seasonal environments, getting the right timing to key life cycle events is vital. To take insectivorous woodland birds as an example, they must lay their eggs early in spring to ensure that their chicks will hatch and grow when food, such as caterpillars, is most plentiful. Because a full month elapses between starting to lay eggs and the maximum food demand of their chicks, the birds use cues in the environment in early spring, such as temperature, to predict what will happen later in the spring. An individual female can therefore be quite flexible in the timing of egg-laying, advancing the time by about two - five days (depending on the species) if spring temperatures are 1C warmer, an ability that we call plasticity. The prediction that the female makes about future conditions remains imperfect however; chicks will often be reared at the wrong time, resulting in few, if any, fledging. With rising spring temperatures the food peak may advance at a rate that is faster than individual birds can keep up with. Therefore, to keep up a species may need to evolve an earlier egg-laying date or, if this is not possible, it may ultimately go extinct.Predicting how climate change will affect species has proven very difficult. If we know how much the optimum timing will shift for a 1C rise in temperature and we know how much a species can track this shift via plasticity, we can work out the amount of ground that evolution will need to make up. Measuring plasticity of timing in response to temperature, whether it be bird egg-laying, frog spawning, plant flowering or tree leafing, is relatively easy. Much more difficult is to work out the amount by which a species needs to shift its timing to track ideal conditions. In fact this has been done for just a single species, the great tit.We will identify the relationship between spring temperatures and optimum timing for a second species, the blue tit, a close relative of the great tit. We will monitor blue tit egg-laying and the availability of caterpillars in four springs and across 50 sites that stretch north of Edinburgh for 200km. We will conduct a huge experiment, swapping hundreds of clutches between the nest boxes of incubating females, to establish when is the best time to lay. We think that the best laying date for a blue tit is likely to be governed by the relationship between temperature and the peak availability of caterpillars. However, the blue tit, like many species is a habitat and feeding generalist and it is possible that the relationship between spring temperature and the best time to lay will vary from one site to another as different caterpillar species become more or less abundant. We will test this idea and if we find support for it this implies that for generalist species we may need to identify the relationship between temperature and the optimum timing anew every time we consider a different population or habitat.Clearly, we cannot expect this huge investment of time or resources to be expended on more than a handful of taxa and yet we need to know how temperature relates to the optimum timing for many taxa. We have developed a method that can infer this relationship from the type of observations on timings that citizen science projects like Nature's Calendar and the BTO Nest Record Scheme have been so effective at collecting. This could greatly increase the number of species for which we can identify this relationship. However, before we encourage much wider use of this method we need first to improve the statistical method and test whether the assumptions it requires are valid in the blue tit.

对于生活在季节性环境中的许多动物和植物来说，获得关键生命周期事件的正确时机至关重要。以食虫的林地鸟类为例，它们必须在早春产卵，以确保它们的雏鸟在食物（如毛虫）最丰富的时候孵化和成长。因为从开始产卵到雏鸟的最大食物需求之间有整整一个月的时间，所以这些鸟会利用早春环境中的线索，比如温度，来预测春天晚些时候会发生什么。因此，一只雌性个体在产卵的时间上可以非常灵活，如果春天的温度比现在高1摄氏度，它会提前大约2 - 5天（取决于物种），这种能力我们称之为可塑性。然而，雌性对未来环境的预测仍然是不完美的;雏鸟经常在错误的时间被饲养，导致很少，如果有的话，羽翼丰满。随着春季气温的上升，食物高峰可能会以比个别鸟类能跟上的速度更快的速度前进。因此，为了维持物种的生存，可能需要进化出更早的产卵日期，否则，如果这是不可能的，它最终可能会灭绝。预测气候变化将如何影响物种已被证明是非常困难的。如果我们知道温度上升1摄氏度时，最佳时间会发生多大的变化，我们知道一个物种可以通过可塑性跟踪这种变化，我们就可以计算出进化需要弥补的土地数量。测量时间对温度反应的可塑性，无论是鸟类产卵，青蛙产卵，植物开花还是树木生叶，都相对容易。更困难的是计算出一个物种需要改变多少时间来跟踪理想的条件。事实上，只有一种山雀做到了这一点，我们将确定春季温度和第二种山雀最佳时间之间的关系，蓝山雀，大山雀的近亲。我们将在四个春天和爱丁堡以北200公里的50个地点监测蓝山雀的产卵和毛虫的可用性。我们将进行一个巨大的实验，在孵化中的雌性巢箱之间交换数百个窝，以确定何时是最佳的产卵时间。我们认为，蓝山雀的最佳产卵日期很可能是由温度和毛虫的峰值之间的关系决定的。然而，与许多物种一样，蓝山雀是一种栖息地和觅食多面手，春季温度和最佳产卵时间之间的关系可能会因地点而异，因为不同的毛毛虫物种变得或多或少丰富。我们将检验这一观点，如果我们找到支持这一观点的证据，这就意味着，对于通才物种，我们可能需要在每次考虑不同的种群或栖息地时重新确定温度与最佳时间之间的关系。显然，我们不能期望将如此巨大的时间或资源投资花费在少数类群上，但我们需要知道温度与许多类群的最佳时间之间的关系。我们已经开发出一种方法，可以从对时间的观察类型中推断出这种关系，公民科学项目如自然日历和BTO巢记录计划在收集方面非常有效。这可能会大大增加我们可以确定这种关系的物种数量。然而，在我们鼓励更广泛地使用这种方法之前，我们首先需要改进统计方法，并测试它所要求的假设在蓝山雀中是否有效。