Table_1_Effects of Benthic Protection Extent on Recovery Dynamics of a Conceptual Seafloor Community.DOCX

Research on disturbance-recovery dynamics has facilitated understanding of species recovery rates, and the likely consequences of human disturbances that operate at large spatial and temporal scales. Benthic Protected Areas (BPA) are a management tool used to protect seafloor communities from disturbance. However, few studies have investigated the benefits of BPAs for benthic communities. A spatially explicit seafloor disturbance model (represented by a 128 × 128 cell grid) was used to simulate recovery dynamics over time in a conceptual benthic community [consisting of eight functional groups (FG)] and investigate interactions between disturbance magnitude and protected area size. The response to disturbance varied between FGs driven by differences in life-history; opportunistic early colonists increased in occupancy whereas other FGs declined, and at high levels of disturbance were extirped. Increasing disturbance accentuated the speed of declines or increases in FG proportional occupancy and increased the recovery times to pre-disturbed levels (if these were not extirped). The inclusion of protected areas lowered the required time for recovery in disturbed areas, with areas adjacent to protected areas recovering faster compared to those further away from the protected areas. Model results suggest that the size of BPAs affects the resilience of the ecosystem, but equally that the effectiveness of protection is heavily dependent on the magnitude of the disturbance in unprotected areas. At high levels of disturbance the permanent loss of the most sensitive FGs occurred in protected areas, resulting in a less functionally diverse and more homogenous conceptual seafloor community. Despite the relatively simple conceptual representation of a benthic community, this heuristic model provides a cost-effective way to explore implications of different management decisions on seafloor communities and highlight model uncertainties for further empirical validation as part of an ecosystem-based management approach.

扰动-恢复动力学领域的研究，有助于深化对物种恢复速率的认知，以及大时空尺度下人类扰动所引发的潜在生态后果的理解。底栖保护区域（Benthic Protected Areas, BPA）是用于保护海底群落免受扰动的管理手段，然而目前鲜有研究探讨底栖保护对海底群落的生态效益。本研究采用空间显式海底扰动模型（以128×128单元格网格表征），模拟由8个功能群（Functional Groups, FG）组成的概念性底栖群落随时间变化的恢复动力学过程，并探究扰动强度与保护面积之间的交互效应。不同功能群对扰动的响应因生活史特征差异而有所不同：机会主义早期拓殖者的占据面积有所增加，其余功能群则出现衰退，在高强度扰动下甚至会发生局部灭绝。扰动强度的提升会加剧功能群相对占据面积的增减速率，并延长其恢复至扰动前水平所需的时长（若未发生局部灭绝的话）。设置底栖保护区域可缩短受扰动区域的恢复时长，且紧邻保护区域的生境相比远离保护区域的生境恢复速度更快。模型结果表明，底栖保护区域的面积会影响生态系统的恢复力，但同时保护措施的有效性在很大程度上取决于未保护区域的扰动强度。在高强度扰动条件下，保护区域内最敏感的功能群会发生永久性丧失，进而导致概念性海底群落的功能多样性降低、群落同质性升高。尽管本研究对底栖群落的概念化表征相对简化，但该启发式模型仍为探究不同管理决策对海底群落的影响提供了一种经济高效的途径，同时也明确了模型的不确定性，可为后续基于生态系统管理框架下的实证验证提供参考。