Noto Akana E, Shurin Jonathan B
Section of Ecology, Behavior and Evolution, University of California, San Diego, La Jolla, California, United States of America.
PLoS One. 2017 Jan 19;12(1):e0169056. doi: 10.1371/journal.pone.0169056. eCollection 2017.
Climate change shuffles species ranges and creates novel interactions that may either buffer communities against climate change or exacerbate its effect. For instance, facilitation can become more prevalent in salt marshes under stressful conditions while competition is stronger in benign environments. Sea-level rise (SLR) is a consequence of climate change that affects the distribution of stress from inundation and salinity. To determine how interactions early in SLR are affected by changes in these two stressors in Mediterranean-climate marshes, we transplanted marsh turfs to lower elevations to simulate SLR and manipulated cover of the dominant plant species, Salicornia pacifica (formerly Salicornia virginica). We found that both S. pacifica and the subordinate species were affected by inundation treatments, and that subordinate species cover and diversity were lower at low elevations in the presence of S. pacifica than when it was removed. These results suggest that the competitive effect of S. pacifica on other plants is stronger at lower tidal elevations where we also found that salinity is reduced. As sea levels rise, stronger competition by the dominant plant will likely reduce diversity and cover of subordinate species, suggesting that stronger species interactions will exacerbate the effects of climate change on the plant community.
气候变化会打乱物种分布范围，并产生新的相互作用，这些相互作用可能会缓冲群落应对气候变化的能力，也可能会加剧其影响。例如，在压力条件下，盐沼中的促进作用可能会更加普遍，而在良性环境中竞争则更强。海平面上升（SLR）是气候变化的一个后果，它会影响因淹没和盐度造成的压力分布。为了确定在地中海气候的盐沼中，海平面上升初期的相互作用如何受到这两种压力源变化的影响，我们将盐沼草皮移植到较低海拔以模拟海平面上升，并控制优势植物物种太平洋海蓬子（原弗吉尼亚海蓬子）的覆盖度。我们发现，太平洋海蓬子和从属物种都受到淹没处理的影响，并且在有太平洋海蓬子存在的情况下，低海拔处从属物种的覆盖度和多样性低于移除太平洋海蓬子时的情况。这些结果表明，在较低潮位处，太平洋海蓬子对其他植物的竞争效应更强，我们还发现此处盐度有所降低。随着海平面上升，优势植物更强的竞争可能会降低从属物种的多样性和覆盖度，这表明更强的物种相互作用将加剧气候变化对植物群落的影响。
