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Restored and artificial wetlands do not support the same waterbird functional diversity as natural wetlands

The restoration of degraded areas and the creation of artificial ecosystems have partially compensated for the continuing loss of natural wetlands. However, the success of these wetlands in terms of the capacity of supporting biodiversity and ecosystem functions is unclear. Natural, restored, and artificially created wetlands present within the Doñana protected area were compared to evaluate if they are equivalent in terms of waterbird functional trait diversity and composition. Functional diversity measures and functional group species richness describing species diet, body mass, and foraging techniques were modelled in 20 wetlands in wintering and breeding seasons. Artificial wetlands constructed for conservation failed to reach the functional diversity of natural and restored wetlands. Unexpectedly, artificial ponds constructed for fish production performed better, and even exceeded natural wetlands for functional richness during winter. Fish ponds stood out as having a unique functional composition, connected with an increase in richness of opportunistic gulls and a decrease in species sensitive to high salinity. Overall, the functional structure of breeding communities was more affected by wetland type than wintering communities. These findings suggest that compensating the loss of natural wetlands with restored and artificial wetlands results in systems with altered waterbird?supported functions. Protection of natural Mediterranean wetlands is vital to maintain the original diversity and composition of waterbird functional traits. Furthermore, restoration must be prioritised over the creation of artificial wetlands, which, even when intended for conservation, may not provide an adequate replacement. informacion[at] Almeida et al. (2020) Comparing the diversity and composition of waterbird functional traits between natural, restored, and artificial wetlands. Freshwater Biology DOI 10.1111/fwb.13618
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From landfills to lakes: gulls as transporters of nutrients

From landfills to lakes: gulls as transporters of nutrients

The lesser black backed gull Larus fuscus is now the second most abundant wintering waterbird in Andalusia, and has increased in numbers in recent years. Fuente de Piedra, the biggest shallow lake in Andalusia and a Ramsar site famous for its flamingo colony, is the principal gulls roosting site in midwinter. Gulls are the most important source of nitrogen and phosphorus inputs to the lake during winter through their guano, and feed in four landfills up to 80 km away in Málaga and Córdoba provinces according to GPS data. This study has quantified the amount of nutrients gulls import to Fuente de Piedra lake. The obtained results provide a vital step to understand the effects of waterbirds in so called "guanotrophication". Gulls take advantage of easy pickings at landfills for feeding, so they can transport an important amount external of nutrients to the lake, where they spend a large proportion of the day. GPS data were used to determine at which landfills gulls were feeding, and the relative importance of each. Although gulls are regularly counted at the lake, gulls are early risers and GPS data showed that most of them had already flown off towards landfills when counting was carried out, and this allowed correcting the counts for missing birds. Movement data were also used to estimate the amount of daytime gulls spent at the lake over different winters, which determines how much of their guano is deposited in the lake. Laboratory analyses of faeces and pellets completed the calculations of nutrient inputs. As estimated in this study, gull contribution seems to be the most important nutrient source in winter with about 10 kg of nitrogen per Ha and 2 kg of phosphorus per Ha. This may bring implications within the ecosystem, whose state seems already eutrophied. Gull excreta is rich in nitrogen and phosphorus, which combined with other nutrient sources such as flamingos, run-off or inputs from the town's Wastewater Treatment Plant, may lead to an excess of nutrients in the lake. There are signs this has caused effects such as the loss of higher plants and a boom in algae. The water levels of Fuente de Piedra vary a lot from one year to another, and low water levels may increase the impact of gull guano. The study found that gulls preferred to spend more time in the lake when water levels were around 30 cm, when islands were available for roosting, and this can lead to increases in nutrient concentrations. This is the first time GPS data is combined with other methods to determine the origin and quantities of nutrients into aquatic systems, and it is the first step to understand the connection between anthropogenic landfills with aquatic bodies. informacion[at] Martín-Vélez et al (2019). Quantifying nutrient inputs by gulls to a fluctuating lake aided by movement ecology methods. Freshwater Biol