The development of relict vegetation at the edges of some ecosystems has taken place particularly in environments where the regeneration of foundational species is declining. As an important stage of regeneration in the Taxodium distichum, this study explored the relationship of cone volume and seed number across environmental gradients in the Mississippi River Alluvial Valley (MRAV) and northern Gulf of Mexico Coast (GOM) in a long-term network of forested wetlands (North American Baldcypress Swamp Network (NABCSN)) from 2007 to 2019. Resembling spheroids, the volumes of Taxodium distichum cones were based on the measured dimensions of the cones collected in swamps across southeastern environmental gradients. Cones with larger volumes also had larger numbers of seeds (r² = 0.423, F = 113.9, p < 0.0001; Linear regression equation: Seed number per cone = 9.8925223 + 0.8854056* Cone volume cm³). Mean cone volumes were related to water availability with highest volumes in locations with moderate amounts of total annual precipitation (e.g., White River National Wildlife Refuge (NWR) Arkansas, Tensas NWR Louisiana, and Morgan Brake NWR Mississippi), and longer periods of annual percent time of site drawdown. Cone volume was high in 2018 following the 2017 mega-flood in the Mississippi River Alluvial Valley (MRAV) generated by Hurricane Harvey. Mean annual air temperature was not related to cone volume. Along the Gulf Coast, mean cone volume increased from east to west from Florida to Texas. Especially near the edge of the range of T. distichum forests, smaller cones may be related to regeneration failure and lower seed numbers to support regeneration. A better understanding of regeneration constraints can inform managers of the emergence of relict status in these forests.

一些生态系统边缘的孑遗植被已经发生，特别是在基础物种的更新正在下降的环境中。作为二尾杉再生的一个重要阶段，本研究在密西西比河冲积谷 (MRAV) 和墨西哥湾北部海岸 (GOM) 的长期网络中探索了锥体体积和种子数之间的关系。从 2007 年到 2019 年的森林湿地（北美 Baldcypress 沼泽网络 (NABCSN)）。类似于球体，Taxodium distichum锥体的体积基于在跨越东南环境梯度的沼泽中收集的锥体的测量尺寸。体积较大的锥体也有较多的种子 (r ² = 0.423，F = 113.9，p < 0.0001；线性回归方程：每个锥体的种子数 = 9.8925223 + 0.8854056* 锥体体积 cm ³ )。平均锥体体积与年降水量中等的地区（例如，怀特河国家野生动物保护区 (NWR) 阿肯色州、路易斯安那州的坦萨斯州 NWR 和密西西比州的摩根布雷克 NWR站点缩减时间。在 2017 年由哈维飓风造成的密西西比河冲积谷 (MRAV) 特大洪水之后，2018 年的锥体体积很高。年平均气温与锥体体积无关。沿着墨西哥湾沿岸，从佛罗里达州到德克萨斯州，平均锥体体积从东到西增加。特别是靠近T. distichum范围的边缘在森林中，较小的锥体可能与再生失败和较低的种子数量有关，以支持再生。更好地了解再生限制可以让管理者了解这些森林中出现的遗物状况。