The response of encrusting coralline algae to canopy loss: an independent test of predictions on an Antarctic coast
The response of encrusting coralline algae to canopy loss: an independent test of predictions on an Antarctic coast
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DOI：
10.1007/s00227-005-0007-4
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发表时间：
2005-09-01
期刊：
影响因子：
2.4
通讯作者：
Gillanders, BM
中科院分区：
文献类型：
--
作者：
Irving, AD;Connell, SD;Gillanders, BM
我们评估了在热带和温带海岸发表的对结壳珊瑚藻类(红藻)生态的观察是否可以用来预测极地海岸的模式和反应，因为那里不存在这样的知识。在东南极凯西附近的潮下岩质海岸，我们检测到覆盖珊瑚藻类的落叶植物与特有藻类Himantothallus Grand difolius形成的树冠有很强的正相关性。大叶珊瑚的实验移除导致珊瑚从红色漂白到粉色/白色，同时它们的光合作用活性下降。这一下降的幅度(平均SE=56.85 8.43%)与温带海岸观测到的(45.98+/-5.91%)非常相似。没有检测到周围水体的营养丰富的积极影响，假设这是为了减轻树冠损失对结壳珊瑚的负面影响。去除大叶黄杨使到达下层的光合作用有效辐射和紫外线辐射的强度增加了三个数量级，为将增强的光照作为冠层损失负面影响的主要原因的模型提供了基础。我们的结果与热带和温带海岸的结果惊人地相似，这表明结壳珊瑚对树冠丧失的反应可能在大距离和环境梯度(热带-温带-极地)上具有预测性。
We assessed whether published observations of the ecology of encrusting coralline algae (Rhodophyta) from tropical and temperate coasts could be used to predict patterns and responses on a polar coast where such knowledge does not exist. On subtidal rocky coasts near Casey, East Antarctica, we detected a strong positive association of understorey encrusting coralline algae with canopies formed by the endemic alga Himantothallus grandifolius. The experimental removal of H. grandifolius caused corallines to bleach from red to pink/ white concomitant with a decline in their photosynthetic activity. The magnitude of this decline (mean SE = 56.85 8.43%) was remarkably similar to that observed on temperate coasts (45.98 +/- 5.91%). Positive effects of nutrient enrichment of the surrounding water, hypothesized to alleviate the negative effects of canopy loss on encrusting corallines, were not detected. Removing H. grandifolius increased the intensity of photosynthetically active radiation and ultra-violet radiation reaching the substratum by three orders of magnitude, providing the basis for models invoking enhanced irradiance as the primary cause of the negative effects of canopy loss. Striking similarities among our results and those from tropical and temperate coasts suggest that responses of encrusting corallines to loss of canopies may have predictive properties across large distances and environmental gradients (tropical-temperate-polar).