Supplementary high-resolution images and videos for "Plant water stress, not termite herbivory, causes Namibia’s fairy circles" (PPEES - doi:10.1016/j.ppees.2022.125698)

These visual data contain the same images and videos as the supplemental Word document (Appendix A), but the images are in high resolution.

Figure captions:

Fig. A.1.
Grass excavations at the Kam-1 plot undertaken in March 2022. Grasses were dead within the FCs and
these wilted plants occurred primarily at the inner edges of the FCs (a,b). Various sizes of still vital and greenish
matrix grasses (upper plants in c-f) have been compared to the dead grasses from within the FCs
(lower plants in c-f). The root morphology of the dead FC grasses is indistinguishable from the roots
of the vital matrix grasses and signs of termite herbivory are completely absent.

Fig. A.2.
Data loggers at the Jag-1 plot. Twelve soil-moisture sensors were installed at 20 cm depth along a transect
connecting two FCs (a,b). No grass cover existed during the drought in 2020, making this setup ideal to study
the effects of active grass growth on the soilwater distribution before, during, and at the end of the rainy seasons (c,d).

Fig. A.3.
Examples of infiltration measurements inside fairy circles in various regions of Namibia such as at Jag-1 in the
NamibRand Nature Reserve (a), at Mar-1 in the Marienfluss Valley (b), and at Tso-1 in the Tsondab Valley (c).

Fig. A.4.
Additional examples of grass excavations undertaken in 2021 at Garub (a,b) and Brandberg
(c-f). Grass death inside FCs at Gar-1 occurred despite the fact that most roots were undamaged and
were covered by an intact rhizosheath (a,b). Also at Brandberg in the Bra-3 plot, the grasses died
inside the FCs (upper plants in c,d) although the roots were undamaged. In the Bra-4 plot, the dead
grasses from within the FCs (upper plants in e,f) had on average longer roots than the vital green
grasses of the matrix (lower plants in e,f).

Fig. A.5.
Continuous soil-moisture measurements from dry to rainy season at Jagkop. This image
shows the download of the data on 25th February 2021, when the grasses were still vital and at full
bloom.

Fig. A.6.
Examples of two FCs where grass excavations have been done in the Jag-1 plot. The drone
images in (a) and (b) have been taken on 23rd February 2021, hence two days prior to the grass
excavations. Comparisons with drone images of the same locations from 15th February 2020 (c,d) and
with Google satellite imagery from 1st August 2016 (e,f) were used to specifically identify new
emerging FCs that are different from the long-lived mature FCs in the surrounding. The arrows in (a)
and (b) point to such exemplary FCs, where grass excavations have been undertaken.

Video A.1.
Short movie of the excavation of grass at the Kam-1 plot near the Kamberg. The movie
was recorded about a week after the grass-triggering rainfall event that occurred on 4th March 2020.

Video A.2.
Short movie of the excavation of grasses at the Bra-4 plot at Brandberg, about 35 days
after grass-triggering rainfall.

本视觉数据集包含与附录A补充Word文档一致的图像与视频，且图像均为高分辨率格式。

图注：
图A.1 2022年3月在Kam-1样地开展的草本植物挖掘采样。精灵圈（fairy circles，以下简称FCs）内部的草本植物已枯死，这些萎蔫植株主要分布于FCs的内边缘（a、b）。将不同大小、仍存活且呈青绿色的基质草本（c-f中上方植株）与FCs内部的枯死草本（c-f中下方植株）进行对比。枯死FC草本的根系形态与存活基质草本的根系无明显差异，且未发现白蚁取食的痕迹。
图A.2 Jag-1样地的数据记录仪。沿连接两个FCs的样带在20cm深度处安装了12个土壤湿度传感器（a、b）。2020年干旱期间该区域无草本覆盖，因此该实验设置非常适合研究雨季前后及雨季末期草本活跃生长对土壤水分分布的影响（c、d）。
图A.3 纳米比亚不同区域精灵圈（fairy circles）内部入渗测量的示例，包括纳米布兰德自然保护区的Jag-1样地（a）、玛丽恩弗卢斯山谷的Mar-1样地（b）以及宗达布山谷的Tso-1样地（c）。
图A.4 2021年在加鲁布（a、b）与布兰德山（c-f）开展的草本植物挖掘采样补充示例。Gar-1样地的FC内部草本虽已枯死，但多数根系未受损伤，且被完整的根鞘包裹（a、b）。同样，在布兰德山Bra-3样地，FC内部的草本植物同样枯死（c-d中上方植株），尽管其根系完好无损。在Bra-4样地，FC内部的枯死草本（e-f中上方植株）的平均根系长度长于存活的青绿色基质草本（e-f中下方植株）。
图A.5 Jagkop样地从旱季到雨季的连续土壤湿度监测数据。该图像拍摄于2021年2月25日，当日草本植物仍存活且处于盛花期，图中展示的是数据下载场景。
图A.6 Jag-1样地两处开展过草本挖掘采样的FC示例。（a）与（b）为2021年2月23日拍摄的无人机影像，即草本挖掘采样的两天前。通过与2020年2月15日同一地点的无人机影像（c、d）以及2016年8月1日的谷歌卫星影像（e、f）对比，可精准识别出与周边长期存在的成熟FC不同的新形成精灵圈。（a）与（b）中的箭头即指向此类已开展草本挖掘采样的典型FC。
视频A.1 Kamberg附近Kam-1样地的草本挖掘采样短片。该视频录制于2020年3月4日触发草本生长的降雨事件约一周后。
视频A.2 布兰德山Bra-4样地的草本挖掘采样短片，拍摄于触发草本生长的降雨事件约35天后。