Variation in coral photosynthesis, respiration and growth characteristics in contrasting light microhabitats: an analogue to plants in forest gaps and understoreys?
Variation in coral photosynthesis, respiration and growth characteristics in contrasting light microhabitats: an analogue to plants in forest gaps and understoreys?
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DOI：
10.1046/j.1365-2435.2003.00731.x
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发表时间：
2003-04-01
影响因子：
5.2
通讯作者：
Hoegh-Guldberg, O
中科院分区：
文献类型：
--
作者：
Anthony, KRN;Hoegh-Guldberg, O
1. 珊瑚礁的结构通常很复杂，形成了多样化的光微生境。与森林植物的模式类似，光的变化可能会推动珊瑚有效光利用和新陈代谢的策略。2．我们研究了马刺和凹槽礁石环境中光照状况的空间分布，并检查了珊瑚 Montipora monasteriata (Forskal 1775)（一种栖息地分布广泛的物种）的光生理学。具体来说，我们检查了对比光微生境中组织和骨骼厚度的变化以及光合作用和代谢反应。3．到达洞穴中和悬垂珊瑚的每日辐照度分别是相似深度（3-5 m）开放栖息地珊瑚的 1-5% 和 30-40%。洞穴栖息地珊瑚的每日净光合作用速率接近于零，表明不同栖息地的生长范围存在两个以上数量级的差异。4。在洞穴和悬垂栖息地中观察到三种光适应或驯化机制：（1）组织层变薄 20-50%，骨骼板变薄 40-60%，使每单位质量的光拦截最大化； (2)单位生物量的光合效率提高两到三倍； (3) 暗呼吸率低。5．来自开放和洞穴栖息地的样本分别表现出很强的适应辐照度下降或上升的能力。然而，洞穴中的标本对进一步降低辐照度的适应能力有限，表明它们生活在接近辐照度极限的地方。6。与森林间隙中某些植物物种的模式类似，M. monasteriata 的形态可塑性和生理灵活性使其能够占据变化超过两个数量级的光照栖息地。
1. The often complex architecture of coral reefs forms a diversity of light microhabitats. Analogous to patterns in forest plants, light variation may drive strategies for efficient light utilization and metabolism in corals.2. We investigated the spatial distribution of light regimes in a spur-and-groove reef environment and examine the photophysiology of the coral Montipora monasteriata (Forskal 1775), a species with a wide habitat distribution. Specifically, we examined the variation in tissue and skeletal thickness, and photosynthetic and metabolic responses among contrasting light microhabitats.3. Daily irradiances reaching corals in caves and under overhangs were 1-5 and 30-40% of those in open habitats at similar depth (3-5 m), respectively. Daily rates of net photosynthesis of corals in cave habitats approximated zero, suggesting more than two orders of magnitude variation in scope for growth across habitats.4. Three mechanisms of photoadaptation or acclimation were observed in cave and overhang habitats: (1) a 20-50% thinner tissue layer and 40-60% thinner skeletal plates, maximizing light interception per unit mass; (2) a two- to threefold higher photosynthetic efficiency per unit biomass; and (3) low rates of dark respiration.5. Specimens from open and cave habitats displayed a high capacity to acclimate to downshifts or upshifts in irradiance, respectively. However, specimens in caves displayed limited acclimation to further irradiance reduction, indicating that these live near their irradiance limit.6. Analogous to patterns for some plant species in forest gaps, the morphological plasticity and physiological flexibility of M. monasteriata enable it to occupy light habitats that vary by more than two orders of magnitude.