Rhodolith growth and CaCO₃ production remain poorly quantified along the SW Atlantic Ocean, and it is difficult to relate the available measurements with biomass estimates. Suboptimal conditions may clarify how harsh environments influence nodule growth and abundance, elucidating their relationship. Off the energetic South American equatorial coast a rhodolith bed (~65 km²), formed mainly by Mesophyllum sp. and Lithophyllum sp., alters the regional sedimentary pattern and sustains a diverse biota. Its nodules present fast growth rates (2.8 mm year⁻¹), but small biomasses (18 nodules∙m⁻² covering 26 ± 3% of the substrate), resulting in a CaCO₃ production of 163.33 g m⁻²∙year⁻¹. Despite the small biomass, the bed seems stable, with living and dead nodules both on and inside the substrate. And the suboptimal environment apparently affects growth and abundance independently. Therefore, fast growth rates and relevant structural roles are not necessarily associated with dense rhodolith assemblages, and ecological assessments of rhodolith beds should consider the dynamics of both individual nodules and the whole population.

在西南大西洋沿岸，Rhodolith的生长和CaCO _3的产生仍然很难量化，很难将可用的测量结果与生物量估计值联系起来。次优条件可以阐明恶劣环境如何影响结节的生长和丰度，从而阐明它们之间的关系。在充满活力的南美赤道海岸外，有一个主要由Mesophyllum sp。形成的菱锰矿床（〜65 km ²）。和Lithophyllum sp。，改变了区域的沉积模式并维持了一个多样的生物区系。其结节的生长速度快（每年2.8 mm ^-1），但生物量较小（18个结节·m ^-2占基质的26±3％），从而形成CaCO ₃年产量163.33 g m ^-2 ∙年^-1。尽管生物量很小，但床似乎很稳定，在基材的内部和内部都有活结和死结节。次优环境显然独立地影响生长和丰度。因此，快速的生长速度和相关的结构作用不一定与致密的菱纹石组合有关，对菱纹石床的生态评估应考虑单个结核和整个种群的动态。