Abstract
Ecological networks are complexes of interacting species, but not all potential links among species are realized. Unobserved links are either missing or forbidden. Missing links exist, but require more sampling or alternative ways of detection to be verified. Forbidden links remain unobservable, irrespective of sampling effort. They are caused by linkage constraints. We studied one Arctic pollination network and two Mediterranean seed-dispersal networks. In the first, for example, we recorded flower-visit links for one full season, arranged data in an interaction matrix and got a connectance C of 15 per cent. Interaction accumulation curves documented our sampling of interactions through observation of visits to be robust. Then, we included data on pollen from the body surface of flower visitors as an additional link 'currency'. This resulted in 98 new links, missing from the visitation data. Thus, the combined visit-pollen matrix got an increased C of 20 per cent. For the three networks, C ranged from 20 to 52 per cent, and thus the percentage of unobserved links (100 - C) was 48 to 80 per cent; these were assumed forbidden because of linkage constraints and not missing because of under-sampling. Phenological uncoupling (i.e. non-overlapping phenophases between interacting mutualists) is one kind of constraint, and it explained 22 to 28 per cent of all possible, but unobserved links. Increasing phenophase overlap between species increased link probability, but extensive overlaps were required to achieve a high probability. Other kinds of constraint, such as size mismatch and accessibility limitations, are briefly addressed.
Abstract from the paper’s OpenAlex record, shown for indexing and research. Copyright remains with the authors or the publisher. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 6
Claim · model-written summary
Flower-visit observations yielded 15 per cent connectance in the Arctic pollination network.
Not reportedTaxon
Verbatim
e0“we recorded flower-visit links for one full season, arranged data in an interaction matrix and got a connectance C of 15 per cent.”
Claim · model-written summary
Pollen examination revealed 98 links absent from visitation observations.
Not reportedTaxon
Verbatim
e0“This resulted in 98 new links, missing from the visitation data.”
e1“data on pollen from the body surface of flower visitors as an additional link”
Claim · model-written summary
Adding pollen links increased connectance to 20 per cent.
Not reportedTaxon
Verbatim
e0“the combined visit-pollen matrix got an increased C of 20 per cent.”
Claim · model-written summary
Across three networks, connectance ranged from 20 to 52 per cent and unobserved links from 48 to 80 per cent.
Not reportedTaxon
Verbatim
e0“For the three networks, C ranged from 20 to 52 per cent, and thus the percentage of unobserved links (100 - C) was 48 to 80 per cent”
Claim · model-written summary
Phenological uncoupling explained 22 to 28 per cent of possible unobserved links.
Not reportedTaxonDirection
Verbatim
e0“Phenological uncoupling (i.e. non-overlapping phenophases between interacting mutualists) is one kind of constraint, and it explained 22 to 28 per cent of all possible, but unobserved links.”
Claim · model-written summary
Greater phenophase overlap increased link probability, with extensive overlap needed for high probability.
Not reportedTaxon
Verbatim
e0“Increasing phenophase overlap between species increased link probability, but extensive overlaps were required to achieve a high probability.”