Periodic Reporting for period 1 - HyChanCEs (Effects of hydrological changes on coastal ecosystems)
Berichtszeitraum: 2020-07-01 bis 2022-06-30
Groundwater dynamics and water table level can greatly influence the physiological performance of plant species, composition of vegetation and ecosystem productivity. Understanding ecosystem sensitivity to hydrological changes such as groundwater decline, and the ecophysiological processes involved, are important challenges. This is particularly relevant in seasonally dry semi-arid coastal dune ecosystems of the Iberian Peninsula (such as Doñana area), where the human pressure is currently high, exacerbating climatic trends of groundwater scarcity.
Thus, this study aimed to evaluate the effects of hydrological drought, particularly water table lowering, on a semi-arid coastal dune ecosystem, and define their vulnerability to groundwater limitation, helping to mitigate the impact of water-resources’ changes on relevant coastal ecosystems.
The project was based on physiological measures, functional diversity, vegetation structure, remote sensing, water-table depth modeling, up-scaling processes, and assessment of integrated vegetation responses to groundwater changes. Community-level assessments, integrated trait syndromes and functional approaches may better point out the vulnerability of vegetation (and habitats/ecosystem) to the reduction of groundwater resources.
The outputs of the project intend to have great implications for water management plans, by signaling vulnerable and endangered coastal areas to current and future groundwater changes. Ultimately, in the long-term, it will contribute to better outline sustainable management strategies conciliating habitat conservation and water-resources use, in semi-arid coastal dune ecosystems of the Iberian Peninsula.
Thus, this study aimed to evaluate the effects of hydrological drought, particularly water table lowering, on a semi-arid coastal dune ecosystem, and define their vulnerability to groundwater limitation, helping to mitigate the impact of water-resources’ changes on relevant coastal ecosystems.
The project was based on physiological measures, functional diversity, vegetation structure, remote sensing, water-table depth modeling, up-scaling processes, and assessment of integrated vegetation responses to groundwater changes. Community-level assessments, integrated trait syndromes and functional approaches may better point out the vulnerability of vegetation (and habitats/ecosystem) to the reduction of groundwater resources.
The outputs of the project intend to have great implications for water management plans, by signaling vulnerable and endangered coastal areas to current and future groundwater changes. Ultimately, in the long-term, it will contribute to better outline sustainable management strategies conciliating habitat conservation and water-resources use, in semi-arid coastal dune ecosystems of the Iberian Peninsula.
Abundance assessments were made (with two different approaches), soil and physiological data were collected, and statistical analysis regarding plant community patterns along a water table depth (WTD) gradient were performed. Models of abundance in function of WTD for the woody community of the studied area of Reserva Biologica de Doñana, and for each functional type, were obtained. The links between physiological traits and vegetation abundance were established, and a potential indicator of groundwater-stress generated. Community functional diversity metrics were analysed in function of WTD lowering, revealing the functional impacts of groundwater depletion on the sandy woody community of Doñana Biological Reserve.
With this work it was found that groundwater depletion influence ecosystem functioning in the studied area. There is a decrease in functional richness and evenness with groundwater lowering. Combining community structure with (multi-trait) physiological approaches is important to better trace the vulnerability of the vegetation to the decline in water table. The basis for creating a suitable indicator of groundwater lowering impacts was achieved. HyChanCEs allowed to understand how groundwater depletion are affecting the functional diversity of important coastal dune woody communities. Importantly, dominant traits on shallow groundwater sites pointed to a community with a higher photosynthetic capacity and better water status. A decrease in functional richness and functional evenness with groundwater lowering reinforced the functional impacts at ecosystem level.
With this work it was found that groundwater depletion influence ecosystem functioning in the studied area. There is a decrease in functional richness and evenness with groundwater lowering. Combining community structure with (multi-trait) physiological approaches is important to better trace the vulnerability of the vegetation to the decline in water table. The basis for creating a suitable indicator of groundwater lowering impacts was achieved. HyChanCEs allowed to understand how groundwater depletion are affecting the functional diversity of important coastal dune woody communities. Importantly, dominant traits on shallow groundwater sites pointed to a community with a higher photosynthetic capacity and better water status. A decrease in functional richness and functional evenness with groundwater lowering reinforced the functional impacts at ecosystem level.
HyChanCEs showed that groundwater depletion strongly influences plant community condition and assemblages, and impact ecosystem functioning. It demonstrated the importance of combining multi-trait physiological approaches with community structure assessments to better trace shifts in the community due to groundwater depletion and define the vulnerability of woody species to the decline in water resources. This is especially important in biodiverse ecosystems that are currently facing climate and human pressure for (ground)water resources, such as our study area of Doñana in the south of Spain. Thus, integrating plant physiology and community ecology across scales through trait(process)-based models to predict hydrological drought mortality, plant community changes and functional impacts is a much-needed challenge which HyChanCEs has tackled.
Project results are expected to be exploited as a reference of water table levels triggering shifts in the woody communities of Iberian coastal dune ecosystems. The information created by this project can be used as a way to flag vulnerable systems (plant species and functional groups) to groundwater depletion, aiming to protect not only biodiversity but ecosystem functions of these relevant coastal dune communities.
Project results are expected to be exploited as a reference of water table levels triggering shifts in the woody communities of Iberian coastal dune ecosystems. The information created by this project can be used as a way to flag vulnerable systems (plant species and functional groups) to groundwater depletion, aiming to protect not only biodiversity but ecosystem functions of these relevant coastal dune communities.