Evaluating the level of agreement between human and time-lapse camera observations of understory plant phenology at multiple scales
Evaluating the level of agreement between human and time-lapse camera observations of understory plant phenology at multiple scales
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DOI：
10.1016/j.ecoinf.2016.02.005
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发表时间：
2016-05-01
影响因子：
5.1
通讯作者：
McDermid, Gregory J.
中科院分区：
文献类型：
--
作者：
Laskin, David N.;McDermid, Gregory J.
数字重复摄影在野外研究中的日益普及，使传统的野外工作得到了帮助，甚至被低成本相机所取代。使用相机的效率是显而易见的，但有一个假设，即它们捕获的信息与人类观察的信息相同。本文旨在确定这两种解释林下植被物候的方法之间的协议水平。我们比较了低成本相机的日常物候观测与每10天进行实地考察的人员。物候期被定义为非光谱，加拿大水牛莓（Shepherdia canadensis）和高山紫云英（Hedysarum alpinum）的物理发育阶段。观测方法之间的关系进行了量化，使用加权Kappa统计在三个空间尺度范围从个别植物的面积高达6公顷。在所有空间尺度上，两种研究物种的营养和生殖物候学的相机观察结果与野外人员的观察结果之间的一致性几乎是完美的（Kappa > 0.9）。协议的水平被认为是更易变的季节初，植物生长更迅速。总的来说，在图像解释中有轻微的偏差，低估了发展速度。延时摄影被认为是实地考察的类似替代品;然而，有些植物物种比其他物种更适合用相机观察。在空间上，它被确定为一个单一的植物的观察是所有需要捕捉周围地区的物候超过6公顷。这项分析是在加拿大西部阿尔伯塔落基山脉的一个单一的生长季节进行的。(C)© 2016 Elsevier B. V.版权所有。
The growing popularity of digital-repeat photography in field research is seeing traditional field efforts being assisted and even replaced by low-cost cameras. The efficiency of using cameras is obvious, but there is an assumption that they capture the same information as observations made by humans. This paper aims to determine the level of agreement between these two methods of interpreting understory vegetation phenology. We compared daily phenological observations made by low-cost cameras with those made by personnel during field visits every 10 days. Phenophases were defined as the non-spectral, physical developmental stages of Canadian buffaloberry (Shepherdia canadensis) and alpine sweetvetch (Hedysarum alpinum). The relationship between observation methods was quantified using a weighted kappa statistic at three spatial scales ranging from individual plants to areas up to 6 ha. Agreement between the camera observations and those made by field personnel was nearly perfect (Kappa > 0.9) for both the vegetative and reproductive phenology of both study species at all spatial scales. The level of agreement was found to be more variable early in the season when plant growth is more rapid. Overall there was a slight bias in the image interpretations to underestimate the rate of development. Time-lapse photography was found to be an analogous replacement for field visits; however, some plant species are more suitable for observation by camera than others. Spatially, it was determined that observations of a single plant are all that is required to capture the phenology of the surrounding region in excess of 6 ha. This analysis was carried out over a single growing season in the in the Rocky Mountains of western Alberta, Canada. (C) 2016 Elsevier B.V. All rights reserved.