Department of Biology, Faculty of Marine and Environmental Science, Campus CEI·MAR, University of Cádiz, Puerto Real, Spain.
PLoS One. 2013 Jul 9;8(7):e67787. doi: 10.1371/journal.pone.0067787. Print 2013.
Possible consequences of climate change in one of the world's largest wetlands (Ibera, Argentina) were analysed using a multi-scale approach. Climate projections coupled to hydrological models were used to analyse variability in wetland water level throughout the current century. Two potential scenarios of greenhouse gas emissions were explored, both resulting in an increase in the inter-annual fluctuations of the water level. In the scenario with higher emissions, projections also showed a long-term negative trend in water-level. To explore the possible response of biota to such water-level changes, species-area relationships of flora and aerial censuses of macro-fauna were analysed during an extraordinary dry period. Plant species richness at the basin scale was found to be highly resistant to hydrological changes, as the large dimension of the wetland acts to buffer against the water-level variations. However, local diversity decreased significantly with low water levels, leading to the loss of ecosystem resilience to additional stressors. The analysis of macro-fauna populations suggested that wetland provides refuge, in low water periods, for the animals with high dispersal ability (aquatic and migratory birds). On the contrary, the abundance of animals with low dispersal ability (mainly herbivorous species) was negatively impacted in low water periods, probably because they are required to search for alternative resources beyond the wetland borders. This period of resource scarcity was also related to increased mortality of large mammals (e.g. marsh deer) around water bodies with high anthropogenic enrichment and cyanobacteria dominance. The synergy between recurrent climatic fluctuations and additional stressors (i.e. biological invasions, eutrophication) presents an important challenge to the conservation of neotropical wetlands in the coming decades.
采用多尺度方法分析了世界上最大湿地之一（阿根廷伊贝拉）的气候变化可能产生的后果。气候预测与水文模型相结合，分析了本世纪内湿地水位的变化。探讨了两种温室气体排放的潜在情景，这两种情景都导致了水位的年际波动增加。在排放较高的情景下，预测还显示水位长期呈负趋势。为了探索生物区系对这种水位变化的可能反应，在一次异常干旱期间分析了植物区系的物种-面积关系和空中大型动物普查。在流域尺度上，植物物种丰富度被发现对水文变化具有高度抗性，因为湿地的大尺寸起到了缓冲水位变化的作用。然而，随着水位降低，局部多样性显著下降，导致生态系统对额外压力源的恢复能力丧失。对大型动物种群的分析表明，在低水位时期，湿地为具有高扩散能力的动物（水生和候鸟）提供了避难所。相反，扩散能力低的动物（主要是食草动物）的丰度在低水位时期受到负面影响，可能是因为它们需要在湿地边界以外寻找替代资源。这种资源稀缺时期也与水体中高人为富营养化和蓝藻优势的大型哺乳动物（如沼泽鹿）的死亡率增加有关。气候变化的周期性波动和额外压力源（即生物入侵、富营养化）之间的协同作用，对未来几十年南美湿地的保护提出了重要挑战。
