Characterizing canopy complexity of natural and restored intertidal oyster reefs (Crassostrea virginica) with a novel laser‐scanning method
Characterizing canopy complexity of natural and restored intertidal oyster reefs (Crassostrea virginica) with a novel laser‐scanning method
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DOI：
10.1111/rec.13973
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发表时间：
2023-07
影响因子：
3.2
通讯作者：
D. Cannon;K. Kibler;J. Taye;S. Medeiros
中科院分区：
文献类型：
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作者：
D. Cannon;K. Kibler;J. Taye;S. Medeiros
牡蛎礁冠层的结构复杂性在促进生物多样性、平衡沉积物预算和调节河口系统的水动力方面发挥着重要作用。尽管牡蛎冠层结构在空间和时间上都是异质的，但牡蛎冠层通常使用简单的一阶量来表征，例如牡蛎密度，这可能缺乏充分参数化珊瑚礁粗糙度的能力。在这项研究中，采用了一种新颖的激光扫描方法来绘制退潮期间牡蛎冠完全暴露时完整参考和恢复的珊瑚礁（恢复年龄：1-4年）的表面。测量结果用于估计整个珊瑚礁表面的水动力相关粗糙度特征（>140 m2；0.50 m 分辨率），提供树冠高度 (hc)、标准差 ( σc )、粗糙度指数 (R) 和分形维数 (D) 的估计。平均冠层高度为 3.6 至 4.9 厘米，冠层高度标准偏差为 1.4 至 2.0 厘米。最年轻（1 年）恢复的珊瑚礁的平均粗糙度指数和分形维数相对较低（R = 1.28；D = 2.67），而较成熟的珊瑚礁冠层则观察到显着增加（4 年：R = 1.56；D = 2.71）。珊瑚礁边缘的结构复杂性始终高于珊瑚礁内部。复杂性的增加与恢复年龄有关，较老的珊瑚礁表现出更复杂的牡蛎冠层。在完整的参考珊瑚礁上观察到最高的分形维数，凸显了珊瑚礁持续生长对于维持高阶结构复杂性的重要性。结果为健康的潮间带牡蛎礁提供了空间明确的表面粗糙度特征，可应用于恢复科学以及自然和基于自然的特征设计。
The structural complexity of oyster reef canopy plays a major role in promoting biodiversity, balancing the sediment budget, and modulating hydrodynamics in estuarine systems. Although oyster canopy structure is both spatially and temporally heterogeneous, oyster canopies are generally characterized using simple first‐order quantities, like oyster density, which may lack the ability to sufficiently parameterize reef roughness. In this study, a novel laser‐scan approach was used to map the surface of intact reference and restored reefs (restoration age: 1–4 years) during low tide, when the oyster canopy was fully exposed. Measurements were used to estimate hydrodynamically relevant roughness characteristics over the entire reef surface (>140 m2; 0.50 m resolution), providing estimates of the canopy height (hc), standard deviation ( σc ), rugosity index (R), and fractal dimension (D). Average canopy heights ranged from 3.6 to 4.9 cm, with canopy height standard deviations between 1.4 and 2.0 cm. Mean rugosity indices and fractal dimensions were relatively low on the youngest (1 year) restored reef (R = 1.28; D = 2.67), with substantial increases observed for more mature reef canopies (4 years: R = 1.56; D = 2.71). Structural complexity was consistently greater on reef margins than in reef interiors. Increases in complexity were linked to restoration age, with older reefs exhibiting more complex oyster canopies. The highest fractal dimension was observed on the intact reference reef, highlighting the importance of sustained reef growth for maintaining higher‐order structural complexity. Results provide spatially explicit surface roughness characterizations for healthy, intertidal oyster reefs, with applications in both restoration science and natural and nature‐based feature design.