A fundamental feature of the natural world is that no species exists in isolation: all organisms interact with other organisms during their lives. These interactions take many forms and the outcome varies with the type of interactions. For example predator-prey interactions are clearly negative for the prey species, but positive for the predator. Other interactions result in positive outcomes for both species, including relationships between pollinators such as bees, birds and flies, and the flowers that they pollinate. An important feature of such interactions is how specialized or generalized it is; that is, how many different pollinators are actually involved in pollinating a particular type of flower, or how many types of flower does a specific pollinator visits.

In a newly published study, I have collaborated with colleagues from Denmark and Brazil to assess how local specialization (within a community) relates to regional specialization (across communities) using two separate data sets from the Brazilian rupestrian grasslands and Canary Island/North African succulent scrub vegetation.

Here’s the citation with a link to the paper (drop me a line if you can’t access it and need a PDF):

Carstensen, D.W., Trøjelsgaard, K., Ollerton, J. and Morellato, L.P.C. (2017) Local and regional specialization in plant–pollinator networks. Oikos (in press) doi:10.1111/oik.04436

The abstract is as follows:

“Specialization of species is often studied in ecology but its quantification and meaning is disputed. More recently, ecological network analysis has been widely used as a tool to quantify specialization, but here its true meaning is also debated. However, irrespective of the tool used, the geographic scale at which specialization is measured remains central. Consequently, we use data sets of plant–pollinator networks from Brazil and the Canary Islands to explore specialization at local and regional scales. We ask how local specialization of a species is related to its regional specialization, and whether or not species tend to interact with a non-random set of partners in local communities. Local and regional specialization were strongly correlated around the 1:1 line, indicating that species conserve their specialization levels across spatial scales. Furthermore, most plants and pollinators also showed link conservatism repeatedly across local communities, and thus seem to be constrained in their fundamental niche. However, some species are more constrained than others, indicating true specialists. We argue that several geographically separated populations should be evaluated in order to provide a robust evaluation of species specialization.”

This is what those two different habitats look like:

If you would like more information on plant-pollinator networks, including details of an edible game for Christmas (!), follow this link to the standingoutinmyfield blog.