Decadal declines in avian herbivore reproduction: density-dependent nutrition and phenological mismatch in the Arctic.
Decadal declines in avian herbivore reproduction: density-dependent nutrition and phenological mismatch in the Arctic.
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鸟类食草动物繁殖的十年下降：北极密度依赖的营养和物候不匹配。
DOI：
10.1002/ecy.1856
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发表时间：
2017
期刊：
影响因子：
4.8
通讯作者：
D. Kellett
中科院分区：
文献类型：
--
作者：
Megan V. Ross;R. Alisauskas;D. Douglas;D. Kellett
对种群动态的充分理解不仅取决于对招募和生存的机械贡献的估计，而且还取决于对驱动这些生命率的生态过程的了解。招募过程尤其可能会持续数年，并可能取决于许多生态复杂性，直到达到性成熟的成年期。我们解决了长期下降（23个繁殖季节，1992-2014）在人均生产的年轻罗斯鹅（陈rossii）和小雪雁（陈caerulescens caerulescens）筑巢在卡拉克湖在加拿大的北极中部。在此期间，有一个同期增加从0.4至110万成年人在这个殖民地筑巢。我们评估了是否（1）密度依赖性的营养不足的繁殖前的女性或（2）高峰雏鹅孵化和高峰饲料质量之间的物候不匹配，推断从NDVI的育雏区，可能已经落后于十年下降的人均生产雏鹅。我们发现，在繁殖前的女性到达筑巢地减少营养储备的年份，在育雏饲养的年轻人的比例组成减少了两个物种。此外，增加峰值雏鹅孵化和峰值饲料质量之间的不匹配贡献了添加剂的雏鹅产量进一步下降，除了延迟筑巢与相关的后续负面影响对窝卵数和巢成功造成的下降。在我们的研究过程中，不匹配的程度增加，因为先进的植被物候没有相应的进展鹅筑巢物候。植被物候明显早于春季测量的温暖地表气温的年份（即，5月25日至6月30日）。我们认为，增加的物候不匹配和抵达女性的营养状况下降的背后人口水平的招聘下降，导致最近的雪雁人口增长的衰减。
A full understanding of population dynamics depends not only on estimation of mechanistic contributions of recruitment and survival, but also knowledge about the ecological processes that drive each of these vital rates. The process of recruitment in particular may be protracted over several years, and can depend on numerous ecological complexities until sexually mature adulthood is attained. We addressed long-term declines (23 breeding seasons, 1992-2014) in the per capita production of young by both Ross's Geese (Chen rossii) and Lesser Snow Geese (Chen caerulescens caerulescens) nesting at Karrak Lake in Canada's central Arctic. During this period, there was a contemporaneous increase from 0.4 to 1.1 million adults nesting at this colony. We evaluated whether (1) density-dependent nutritional deficiencies of pre-breeding females or (2) phenological mismatch between peak gosling hatch and peak forage quality, inferred from NDVI on the brood-rearing areas, may have been behind decadal declines in the per capita production of goslings. We found that, in years when pre-breeding females arrived to the nesting grounds with diminished nutrient reserves, the proportional composition of young during brood-rearing was reduced for both species. Furthermore, increased mismatch between peak gosling hatch and peak forage quality contributed additively to further declines in gosling production, in addition to declines caused by delayed nesting with associated subsequent negative effects on clutch size and nest success. The degree of mismatch increased over the course of our study because of advanced vegetation phenology without a corresponding advance in Goose nesting phenology. Vegetation phenology was significantly earlier in years with warm surface air temperatures measured in spring (i.e., 25 May-30 June). We suggest that both increased phenological mismatch and reduced nutritional condition of arriving females were behind declines in population-level recruitment, leading to the recent attenuation in population growth of Snow Geese.