Terando Adam J, Youngsteadt Elsa, Meineke Emily K, Prado Sara G
Department of Interior Southeast Climate Science Center US Geological Survey Raleigh NC USA.
Department of Applied Ecology North Carolina State University Raleigh NC USA.
Ecol Evol. 2017 Oct 20;7(23):9890-9904. doi: 10.1002/ece3.3499. eCollection 2017 Dec.
In light of global climate change, ecological studies increasingly address effects of temperature on organisms and ecosystems. To measure air temperature at biologically relevant scales in the field, ecologists often use small, portable temperature sensors. Sensors must be shielded from solar radiation to provide accurate temperature measurements, but our review of 18 years of ecological literature indicates that shielding practices vary across studies (when reported at all), and that ecologists often invent and construct ad hoc radiation shields without testing their efficacy. We performed two field experiments to examine the accuracy of temperature observations from three commonly used portable data loggers (HOBO Pro, HOBO Pendant, and iButton hygrochron) housed in manufactured Gill shields or ad hoc, custom-fabricated shields constructed from everyday materials such as plastic cups. We installed this sensor array (five replicates of 11 sensor-shield combinations) at weather stations located in open and forested sites. HOBO Pro sensors with Gill shields were the most accurate devices, with a mean absolute error of 0.2°C relative to weather stations at each site. Error in ad hoc shield treatments ranged from 0.8 to 3.0°C, with the largest errors at the open site. We then deployed one replicate of each sensor-shield combination at five sites that varied in the amount of urban impervious surface cover, which presents a further shielding challenge. Bias in sensors paired with ad hoc shields increased by up to 0.7°C for every 10% increase in impervious surface. Our results indicate that, due to variable shielding practices, the ecological literature likely includes highly biased temperature data that cannot be compared directly across studies. If left unaddressed, these errors will hinder efforts to predict biological responses to climate change. We call for greater standardization in how temperature data are recorded in the field, handled in analyses, and reported in publications.
鉴于全球气候变化，生态学研究越来越多地关注温度对生物体和生态系统的影响。为了在野外以与生物学相关的尺度测量气温，生态学家通常使用小型便携式温度传感器。传感器必须屏蔽太阳辐射以提供准确的温度测量，但我们对18年生态文献的综述表明，屏蔽做法在不同研究中各不相同（即便有报告），而且生态学家常常自行发明并构建临时辐射屏蔽装置，却不测试其有效性。我们进行了两项野外实验，以检验三种常用便携式数据记录器（HOBO Pro、HOBO Pendant和iButton hygrochron）在配备制造的吉尔屏蔽装置或由塑料杯等日常材料定制的临时屏蔽装置时温度观测的准确性。我们将这个传感器阵列（11种传感器 - 屏蔽组合，每种组合5个重复）安装在位于开阔地和森林地的气象站。配备吉尔屏蔽装置的HOBO Pro传感器是最准确的设备，相对于每个站点的气象站，平均绝对误差为0.2°C。临时屏蔽处理的误差范围为0.8至3.0°C，在开阔地误差最大。然后，我们在五个城市不透水表面覆盖量不同的地点各部署了每种传感器 - 屏蔽组合的一个重复，这带来了进一步的屏蔽挑战。对于不透水表面每增加10%，与临时屏蔽装置配对的传感器偏差最多增加0.7°C。我们的结果表明，由于屏蔽做法各异，生态文献中可能包含偏差很大的温度数据，无法在不同研究之间直接比较。如果不解决这些误差，将阻碍预测生物对气候变化反应的努力。我们呼吁在野外温度数据的记录方式以及分析处理和出版物报告方面实现更大程度的标准化。
