Shading decreases and delays NDVI and flowering of prostrate Arctic shrubs
Shading decreases and delays NDVI and flowering of prostrate Arctic shrubs
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遮荫减少并延迟了 NDVI 和匍匐的北极灌木的开花
DOI：
10.1139/as-2020-0043
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发表时间：
2022
期刊：
影响因子：
3.3
通讯作者：
Hollister, Robert D.
中科院分区：
文献类型：
--
作者：
May, Jeremy L.;Oberbauer, Steven F.;Unger, Steven L.;Simon, Matthew J.;Betway, Katlyn R.;Hollister, Robert D.
灌木生长和树冠覆盖的增加是北极地区对气候变暖的充分记录的社区反应。较大的落叶灌木的一个重要后果是遮蔽匍匐植物物种，其中许多是花蜜和浆果的重要来源。在这里，我们提出了两个匍匐灌木，越桔vitis-idaeaL的遮荫实验的影响。和高山牛蒡（Arctous alpinaL.）在阿拉斯加北方的两个生长季节里。我们实施了三个层次的阴影（没有阴影，40%的阴影，80%的阴影）在干燥的石楠和潮湿的酸性苔原。地块进行了监测土壤水分含量，地表温度，归一化植被指数（NDVI），开花。平均而言，遮荫可以降低两个群落的地表温度（0.7 °C至5.3 °C），增加土壤含水量（0.5%至5.6%）。两个物种和地块级的NDVI值延迟峰值的时间（7至13天），并在最高的阴影下降。这两个物种的花丰度较低，在阴影区和开花高峰期延迟（3至8天）与对照组相比。时间的变化可能导致物候不匹配，并可能影响北极的其他营养水平，因为花朵和由此产生的浆果都是动物的重要食物来源。
Increases in shrub growth and canopy cover are well documented community responses to climate warming in the Arctic. An important consequence of larger deciduous shrubs is shading of prostrate plant species, many of which are important sources of nectar and berries. Here, we present the impact of a shading experiment on two prostrate shrubs,Vaccinium vitis-idaeaL. andArctous alpinaL., in northern Alaska over two growing seasons. We implemented three levels of shading (no shade, 40% shade, and 80% shade) in dry heath and moist acidic tundra. Plots were monitored for soil moisture content, surface temperature, normalized difference vegetation index (NDVI), and flowering. Shading was shown to, on average, lower surface temperature (0.7 °C to 5.3 °C) and increase soil moisture content (0.5% to 5.6%) in both communities. Both species- and plot-level NDVI values were delayed in timing of peak values (7 to 13 days) and decreased at the highest shading. Flower abundance of both species was lower in shaded plots and peak flowering was delayed (3 to 8 days) compared with controls. Changes in timing may result in phenological mismatches and can impact other trophic levels in the Arctic as both the flowers and resulting berries are important food sources for animals.