Effects of temperature and interspecific competition on growth and photosynthesis of two endemic Antarctic Desmarestia species
Effects of temperature and interspecific competition on growth and photosynthesis of two endemic Antarctic Desmarestia species
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温度和种间竞争对两种南极特有物种生长和光合作用的影响
DOI：
10.1127/algol_stud/2016/0269
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
Bartsch I
中科院分区：
文献类型：
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作者：
Zacher K;Savaglia V;Bartsch I
本文报道的褐藻Desmarestia menziesii和D.在西南极半岛（WAP）的潮下带中上部，安凯普形成了茂密的水下森林，在这一沿海生态系统中发挥着重要作用。在过去的50年里，WAP的海水温度上升了约2 °C，并且由于全球变暖，未来可能会进一步上升。这可能会对这些冷水适应藻类的生理表现和群落相互作用产生影响。在实验室实验中，我们研究了温度升高对两个物种的光合反应，生长和种间竞争的影响。温度升高（5 °C），D.与0 °C相比，两种植物的光合作用最佳量子产率均较高。既没有种间竞争，也没有竞争和温度之间的相互作用。测定了D. menziesii比D.安塞普结果表明，在该设置中，温度从0°C升高到5°C对两种Desmarestia物种都没有危害。总体而言，D. menziesii是非常低的，可能反映了在连续长日照条件下的休眠状态，从而可能掩盖了温度对生长的影响。为了确定这些关键物种在全球变化情景下的实际生存阈值，进一步的多因素实验非常重要，包括现场材料，不同的藻类生命阶段和繁殖过程。
The brown algae Desmarestia menziesii and D. anceps form dense underwater forests at the Western Antarctic Peninsula (WAP) in the upper to mid subtidal and play an important role in this coastal ecosystem. Seawater temperatures at the WAP increased by about 2 °C in the last 50 years and probably will rise further in future due to global warming. This may have consequences for the physiological performance and community interactions of these cold water adapted algae. In laboratory experiments with culture material we investigated the influence of increased temperatures on the photosynthetic response, growth and interspecific competition of both species. Increased temperature (5 °C) induced a higher growth rate of D. anceps and a higher optimum quantum yield of photosynthesis in both species compared to 0 °C. Neither interspecific competition nor interactions between competition and temperature were detected. The photosynthetic performance (rETRmax , α and Ek ) of D. menziesii was significantly more often affected by temperature increases than of D. anceps. It was shown that a temperature increase from 0°C to 5°C was not harmful for both Desmarestia species in this set-up. Generally, growth of D. menziesii was very low possibly reflecting a dormancy state under continuous long-day conditions and thereby may have masked the influence of temperature on growth. In order to determine realistic survival thresholds of these key species of the Antarctic coastal ecosystem under global change scenarios, further multifactorial experiments are of great importance, including field material, different algal life stages and reproductive processes.