Ascidian coverage change from removal experiments in rocky intertidal Marine Protected Areas in the San Juan Islands from 2008-2011 (Subtidal Preserves project)

<p>In this study, we tested the hypothesis that red urchins (Strongylocentrotus franciscanus) and lined chitons (Tonicella spp.) are redundant in the maintenance of available space, defined here as encrusting algae and bare rock. In a factorial field experiment replicated at three sites, we reduced the densities of urchins and chitons for nine months. The effects of grazers were interpreted in the context of natural temporal variation by monitoring the benthic community one year before, during, and after grazer removal.</p>

<p>Physical data - temperature, salinity, conductivity - can also be viewed online at <a href=\"http://nvs.nanoos.org/Explorer\">http://nvs.nanoos.org/Explorer</a> and <a href=\"http://depts.washington.edu/fhl/wx.html\">http://depts.washington.edu/fhl/wx.html</a></p>

<p><strong>Reference for this dataset:</strong></p>

<p><a href=\"http://www.plosone.org/article/authors/info%3Adoi%2F10.1371%2Fjournal.pone.0078969;jsessionid=3865D9F9ECBBD3174EF10F65C01F3CA8\" target=\"_blank\">Elahi R, Sebens KP (2013) Experimental Removal and Recovery of Subtidal Grazers Highlights the Importance of Functional Redundancy and Temporal Context. PLoS ONE 8(11): e78969. doi:10.1371/journal.pone.0078969</a></p>

<p><strong>Associated physical underwater and&nbsp;weather data:</strong></p>

<p>See&nbsp;<a href=\"http://140.142.199.7/vdv/VV_Frame.php\">http://140.142.199.7/vdv/VV_Frame.php</a></p>

本研究旨在验证如下假说：红海胆（Strongylocentrotus franciscanus）与带石鳖（Tonicella spp.）在维持可用空间（本研究中将其定义为结壳藻类与裸露岩石）方面存在功能冗余（functional redundancy）。我们在三个地点重复开展析因野外实验（factorial field experiment），连续九个月降低海胆与石鳖的种群密度。通过在移除植食性动物前一年、移除期间及移除后一年对底栖群落（benthic community）进行监测，我们结合自然时间变异背景解析了植食性动物的生态效应。

相关物理数据（涵盖温度、盐度、电导率）亦可通过以下在线链接查看：<a href="http://nvs.nanoos.org/Explorer">http://nvs.nanoos.org/Explorer</a> 与 <a href="http://depts.washington.edu/fhl/wx.html">http://depts.washington.edu/fhl/wx.html</a>

**本数据集参考文献：**

<a href="http://www.plosone.org/article/authors/info%3Adoi%2F10.1371%2Fjournal.pone.0078969;jsessionid=3865D9F9ECBBD3174EF10F65C01F3CA8" target="_blank">Elahi R, Sebens KP (2013) 《潮下带植食性动物的移除与恢复凸显功能冗余及时间背景的重要性》，PLoS ONE 8(11): e78969. DOI:10.1371/journal.pone.0078969</a>

**配套水下物理与气象数据：**

请访问 <a href="http://140.142.199.7/vdv/VV_Frame.php">http://140.142.199.7/vdv/VV_Frame.php</a> 获取