Response and Recovery of Low-Salinity Marsh Plant Communities to Presses and Pulses of Elevated Salinity
Response and Recovery of Low-Salinity Marsh Plant Communities to Presses and Pulses of Elevated Salinity
复制标题
DOI：
10.1007/s12237-018-00490-1
复制
发表时间：
2018-12
影响因子：
2.7
通讯作者：
Fan Li;S. Pennings
中科院分区：
文献类型：
--
作者：
Fan Li;S. Pennings
在河口，未来海平面和河流流量的变化将导致盐分入侵低盐度潮汐沼泽。为了研究潮汐淡水沼泽植物群落对盐分脉冲的差异响应和恢复过程，通过3 × 5因子温室试验，研究了不同盐度水平(3、5和10个实际盐度单位)和不同脉冲持续时间(5、10、15、20和30天/月)对潮汐淡水沼泽植被群落组成的影响。10个月后，还检查了受干扰社区的恢复情况。结果表明，盐度越高、持续时间越长的处理对群落组成的影响越大。盐敏性物种的减少导致物种重新排序，物种丰富度降低，地上生物量下降。大多数植物物种能够在不到1年的时间内从低盐度、短时间的盐分脉冲中恢复过来。然而，由于并不是所有物种在重度盐碱化处理中都得到了恢复，在处理期间严重盐碱化的处理在恢复期末物种丰富度仍然很低。相反，在重度盐化处理中，植物地上生物量完全恢复。尽管脉动环境变化的幅度和持续时间对群落组成有很大影响，但群落组成的变化防止了生产力的长期下降。因此，在本研究系统中，环境变化对物种组成的影响比对生态系统过程的影响更大。
In estuaries, future variation in sea level and river discharge will lead to saline intrusion into low-salinity tidal marshes. To investigate the processes that control the differential response and recovery of tidal freshwater marsh plant communities to saline pulses, a 3 × 5 factorial greenhouse experiment was conducted to examine the effects of a range of salinity levels (3, 5, and 10 practical salinity units (PSU)) and pulse durations (5, 10, 15, 20, and 30 days per month) on community composition of tidal freshwater marsh vegetation. Recovery of perturbed communities was also examined after 10 months. The results showed that community composition was increasingly affected by the more-saline and longer-duration treatments. The increasing suppression of salt-sensitive species resulted in species reordering, decreased species richness, and decreased aboveground biomass. Most of the plant species were able to recover from low-salinity, short-duration saline pulses in less than 1 year. However, because not all species recovered in the heavily salinized treatments, species richness at the end of the recovery period remained low for treatments that were heavily salinized during the treatment period. In contrast, plant aboveground biomass fully recovered in the heavily salinized treatments. Although the magnitude and duration of pulsed environmental changes had strong effects on community composition, shifts in community composition prevented long-term reductions in productivity. Thus, in this study system, environmental change affected species composition more strongly than it did ecosystem processes.