Spatial patterns of seasonal crop production suggest coordination within and across dryland agricultural systems of Hawaiʻi Island
Spatial patterns of seasonal crop production suggest coordination within and across dryland agricultural systems of Hawaiʻi Island
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季节性作物生产的空间格局表明夏威夷岛旱地农业系统内部和之间的协调
DOI：
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发表时间：
2018
期刊：
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通讯作者：
T. Giambelluca
中科院分区：
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作者：
A. Kagawa;N. Lincoln;Seth Quintus;M. Lucas;T. Giambelluca
夏威夷旱地农业被认为在古代国家的兴起和政治权力的巩固中发挥了重要作用。与此同时，旱地农田系统的农业生产对气候随时间变化的敏感性会对竞争和合作的经济和政治关系产生影响。在这项研究中，我们探讨是否以及如何每年的气候周期可能会限制季节性耕作和作物生产的三个雨水灌溉的领域系统在夏威夷的夏威夷群岛。我们利用最近开发的每月网格气候数据集的夏威夷群岛比较科哈拉，科纳，和Ka Kahara场系统的平均年气候和季节性。我们发现，尽管表面相似的海拔和年降雨量，外地系统不同的气候变量与蒸发水分损失和雨季的时间。干旱，蒸发需求与降雨量的比率，是强烈的季节性为科哈拉和Ka相对科纳。当我们施加温度和湿度的标准，可视化的季节性种植甘薯（Ipomea batatas）定义的信封，我们发现强大的空间格局与生长季节的开始和长度，这些表明作物生产的季节性互补性内和田间系统之间。这种互补性表明，外地系统内部和外地系统之间通过合并、强制或加强合作进行协调，本来可以缓解周期性的粮食紧张，有助于更稳定的政治等级制度，这可以解释它们各自发展时间表的相似性。我们认为，我们的方法表征旱地种植的季节性限制提供了一个有用的工具，在这些和其他雨水灌溉的旱地系统在夏威夷和热带地区推进持续的恢复和研究。
Hawaiian dryland agriculture is believed to have played an important role in the rise of archaic states and consolidation of political power. At the same time, the sensitivity of agricultural production in dryland field systems to temporal variability in climate would have had implications for economic and political relationships, both competitive and cooperative. In this study, we explore whether and how annual cycles of climate might have constrained seasonal cultivation and crop production in three rain-fed field systems on the Island of Hawaiʻi. We utilized a recently developed monthly gridded climate dataset for the Hawaiian Islands to compare the Kohala, Kona, and Kaʻū field systems in terms of mean annual climate and seasonality. We found that despite superficial similarities in elevation and annual rainfall, the field systems differ in climatic variables associated with evaporative water loss and in the timing of the rainy season. Aridity, a ratio of evaporative demand to rainfall, is strongly seasonal for Kohala and Kaʻū relative to Kona. When we imposed temperature and moisture criteria to visualize seasonal cultivation envelopes defined for sweet potato (Ipomea batatas), we found strong spatial patterns associated with the onset and length of the growing season, and these suggest seasonal complementarity in crop production within and between field systems. This complementarity indicates coordination both within and between field systems through consolidation, coercion, or increased cooperation could have alleviated periodic food stress and contributed to more stable political hierarchies, which may explain similarities in their respective chronologies of development. We suggest that our approach for characterizing seasonal constraints to dryland cultivation provides a useful tool for advancing continued restoration and research in these and other rain-fed dryland systems across Hawaiʻi and the tropics.