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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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Stochastic and deterministic effects on interactions between canopy and recruiting species in forest communities

Stochastic and deterministic effects on interactions between canopy and recruiting species in forest communities

Interactions between established (canopy) and recruiting individuals (recruits) are pervasive in plant communities. Studies on recruitment in forests have mainly focused on negative density-dependent conspecific interactions, while the outcomes of heterospecific canopy–recruit interactions have received much less attention and are generally assumed to be driven by stochastic processes. Herein, the relative influence of stochastic (abundance) and deterministic (species identity and phylogenetic distance) effects on the frequency of canopy–recruit interactions are explored, and the interactions in terms of their spatial consistency and effect on recruitment (depressing, neutral or enhancing) are characterized. In 12 plots (50 × 50 m) of mixed pine–oak forests in southern Spain, all saplings recruiting beneath 56 shrub and tree species, and in open areas not covered by woody plants were identified. Generalized linear mixed models were used to investigate the influence of stochastic and deterministic processes on the frequency of canopy– recruit interactions, on their spatial consistency and their effects on recruitment, and applied neutral null models to evaluate the spatial consistency in the occurrence of interactions across plots. Deterministic and stochastic interactions were equally common, emphasizing the prevalence of non-neutral effects. Among the realized interactions, 36.8% enhanced recruitment, 49.05% were neutral, and 14.1% depressed recruitment. Many potential interactions (42.08%) were not observed in any study sites, presumably due to the scarcity of the interacting species. Moreover, the probability that two species formed a canopy–recruit interaction, the frequency of their interaction and the probability that the interaction had an enhancing effect on recruitment, all increased with the phylogenetic distance between the interacting species. However, the prevalence of these effects depended on the recruitment environment (heterospecific, conspecific or open). Recruitment-enhancing interactions between heterospecifics were more consistently realized in different sites than neutral or depressing interactions. The establishment of canopy–recruit interactions (which species recruits beneath which others, and how often) is not simply determined by stochastic events. Indeed, due to their prevalence, deterministic canopy–recruit interactions may be important drivers of plant community dynamics. informacion[at] Alcántara et al 2018. Stochastic and deterministic effects on interactions between canopy and recruiting species in forest communities. Functional Ecology 32: 2264–2274.