Tree lines and hedgerows are typical features in European countryside; they add to the charm of cultivated fields and inspire peaceful and relaxing thoughts. But they also have a less seen, crucial role in biodiversity conservation as they act as safe corridors for plants to disperse their seeds.
In fact, cultivated fields can be unsurmountable barriers for forest plant species that are very habitat-demanding. For them, tree lines, hedgerows and alleys work as safe corridor, the so- called stepping- stones, to migrate from one place to another.
But the question is: are these corridors enough? Or is their functionality limited by the presence of ecological filters?
The dispersal of forest-related plants through green corridors is influenced by different factors and therefore it is not possible to design a single optimal structure for these corridors. However, they should at least incorporate a diversity of shade levels and facilitate the visit of forest insects, birds and mammals that can act as dispersal vectors for the seeds of forest-dwelling plants
To investigate in depth the limits and opportunities of wooded corridors, the authors studied multiple plant traits related to dispersal in the rural landscape of Estonia. They found that the quantitative metrics used so far didn’t include enough traits in their list, leading to interpretational limitations. In fact, different plants have different optimal trait levels and different ecological responses.
The authors propose an all-inclusive methodological solution consisting of survey set-ups, indicator set selections and quantitative intensity metrics. In fact, they believe that the debate concerning the true role of linear green corridors is partially due to methodological reasons.
Paal T.; Zobel K.; Liira J. Standardized response signatures of functional traits pinpoint limiting ecological filters during the migration of forest plant species into wooded corridors. Ecological Indicators, 2020, 108, 105688. https://doi.org/10.1016/j.ecolind.2019.105688
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