The amount of macroalgal biomass is an important ecosystem variable. Estimates can be made for a sampled area or values can be extrapolated to represent biomass over a larger region. Typically biomass is scaled-up using the area multiplied by the mean: a non-spatial method. Where algal biomass is patchy or shows gradients, non-spatial estimates for an area may be improved by spatial interpolation. A separate issue with scaling-up biomass estimates is that conventional confidence intervals based on the standard error (SE) of the sample may not be appropriate. The issues around interpolation and confidence intervals were examined for three fucoid species using data from 40 × 0.25 m-2 quadrats thrown in a 0.717 ha sampling plot on the shore of Galway Bay. Despite evidence of spatial autocorrelation, interpolation did not appear to improve estimates of the total plot biomass of Fucus serratus and F. vesiculosus. In contrast, interpolated estimates for Ascophyllum nodosum had less error than those based on the non-spatial method. Bootstrapped confidence intervals had several benefits over those based on the SE. These benefits include the avoidance of negative confidence limits at low sample sizes and no assumptions of normality in the data. If there is reason to expect strong patchiness or a gradient of biomass in the area of interest, interpolation is likely to produce more accurate estimates of biomass than non-spatial methods. Development of methodologies for biomass would benefit from more definition of local and regional gradients in biomass and their associated covariates.

中文翻译：

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通过样方调查估算更大规模的潮间带海藻生物量。


大型藻类生物量是一个重要的生态系统变量。可以对采样区域进行估计，或者可以推断值以代表更大区域的生物量。通常，生物量是使用面积乘以平均值来放大的：一种非空间方法。当藻类生物量不均匀或呈现梯度时，可以通过空间插值来改进区域的非空间估计。扩大生物量估计的另一个问题是基于样本标准误差 (SE) 的传统置信区间可能不合适。使用戈尔韦湾沿岸 0.717 公顷采样区内 40 × 0.25 m-2 样方的数据，检查了三种岩藻类物种的插值和置信区间问题。尽管有空间自相关的证据，但插值法似乎并没有改善对锯缘墨角藻和水泡墨角藻总生物量的估计。相比之下，泡叶藻的插值估计误差小于基于非空间方法的插值估计。与基于 SE 的置信区间相比，自举置信区间有几个优点。这些好处包括避免小样本量下的负置信限以及不假设数据正态性。如果有理由预期感兴趣区域中存在强烈的斑块或生物量梯度，则插值可能会比非空间方法产生更准确的生物量估计。生物量方法学的开发将受益于对生物量及其相关协变量的局部和区域梯度的更多定义。