Many a little makes a mickle: Global review about the importance of rodents and lagomorphs in seed dispersal

Our review paper by Laura Godó has recently been published in GECCO.

Godó, L., Valkó, O., Borza, S., Deák, B. (2022): A global review on the role of small rodents and lagomorphs (clade Glires) in seed dispersal and plant establishment. Global Ecology and Conservation 33: e01982. doi: 10.1016/j.gecco.2021.e01982 [IF2020: 3.380] 

The paper is open access, and can be freely downloaded from here.

This is a comprehensive review based on approximately 600 papers where we evaluated the role of small herbivores of the orders Rodentia and Lagomorpha in seed dispersal. The studied animal taxa occur in all continents, in all terrestrial habitat types, they form a diverse group with more than 2100 species. Practically these animals occur wherever seeds are present, so all seeds are eaten, dispersed or ignored by a small herbivore. Despite these, there are many knowledge gaps regarding the role of Glires in seed dispersal and many potentially important mechanisms have not been studied yet.

 

Examples of the most important small seed disperser mammals.

In our review we discuss the types of rodent- and lagomorph-mediated seed dispersal, with a special emphasis on epizoochory (dispersal on fur), endozoochory (dispersal  through the digestive tract), synzoochory (dispersal through food caches) and caliochory (dispersal through nest material). Then we evaluate the environmental factors and biotic interactions, such as soil properties, habitat structure, predation risk, that mediate seed dispersal by Glires. We also give an overview on the often human-induced threat factors that affect these seed dispersal processes, such as habitat loss and fragmentation, defaunation, invasive alien species. We higlight the peculiarities of Glires-mediated seed dispersal compared to dispersal by large herbivores and show examples on plant adaptations that influence Glires-mediated seed dispersal. Finally, we evaluate these plant-animal relationships from the perspective of ecosystem services and disservices and identify the major knowledge gaps and promising future research avenues. 

Finally, this article turned to be a very comprehensive, and hopefully very interesting review paper and congratulations to Laura for her hard work during the reading, writing and review process!

Abstract

Zoochory is an ecologically and evolutionarily important seed dispersal type. The decline and extinction of seed-dispersing large herbivores severely threatens dispersal-driven ecosystem processes in many regions. Hence the relative importance of small rodents and lagomorphs (Glires, Mammalia) as dispersal vectors might increase due to their ubiquity, diversity and abundance. Here we provide a review of rodent- and lagomorph-mediated seed dispersal based on approximately 600 papers found in an extensive literature search. We highlight that small rodents and lagomorphs disperse seeds via various mechanisms. The seldom documented epi- and endozoochory are probably universal in these groups. Due to their small home range, short fur and small body size, these mechanisms generally operate at small scales and mainly for small seeds. Taxon-specific feeding, nesting and behavioural characteristics provide a wide spectrum of other seed dispersal types, such as synzoochory (food caching). The studied taxa generally support seed dispersal within a particular habitat patch, contributing to the persistence of local populations, but in rare cases, long-distance dispersal events might occur. Besides seed dispersal, rodents and lagomorphs can also support plant establishment and provide safe sites for seeds where they can survive stochastic events. Studies reviewed here show a strong bias both in scope and geographical distribution: synzoochorous dispersal of woody plants is known in detail, and most studies were conducted in the same few countries and habitat types. In contrast, other mechanisms such as endozoochory, epizoochory and habitat types like grasslands and anthropogenic habitats have rarely been studied. We show examples on ecosystem services and disservices related to rodent- and lagomorph-mediated seed dispersal as well as the importance of these processes in habitat conservation and restoration.