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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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Humans and scavenging raptors facilitate Argentine ant invasion in Doñana National Park

Humans and scavenging raptors facilitate Argentine ant invasion in Doñana National Park

Biotic resistance by native communities could have a role in the spread of invasive species. Native communities with higher species richness should be less susceptible to invasion by exotic species than those with fewer component species, interspecific interactions acting as biotic barriers by creating a highly competitive environment. This seems to be the case in the invasion of the Argentine ant, Linepithema humile, but only when the environment is unfavorable for the survival of the invader. The progress of Argentine ant invasion through favorable and unfavorable habitats of Doñana National Park was studied across three temporal snapshots covering three decades (1992, 2000, 2016). Biotic resistance of the native community was assessed using species richness, as well as dominance and community structure. The role of abiotic factors (quality of surrounding habitat and spatial variables) and of potential vectors of Argentine ant dispersal across unfavorable areas was also explored. No evidence of biotic resistance was found. On the contrary, invasion proceeded from trees with higher ant species richness, probably because those trees are larger and provide more resources and better protection from aridity. Furthermore, evidence was found that the invasion of new trees across a matrix of unfavorable habitat could be influenced not only by humans, but also by scavenging avian predators, which could act as vectors of ant dispersal through transport of carrion also exploited by the ants. Such leapfrog expansion through mobile predators could represent an overlooked mechanism that would enrich our understanding of invasion dynamics and provide potential opportunities for management of invasive species. informacion[at] Castro-Cobo et al (2019) Humans and scavenging raptors facilitate Argentine ant invasion in Doñana National Park: no counter-effect of biotic resistance. Biol Invasions 21:2221–2232. Doi 10.1007/s10530-019-01971-5