Abstract
We conducted a study of natural variation in functional leaf traits and herbivory in 116 clones of European aspen, Populus tremula L., the Swedish Aspen (SwAsp) collection, originating from ten degrees of latitude across Sweden and grown in a common garden. In surveys of phytophagous arthropods over two years, we found the aspen canopy supports nearly 100 morphospecies. We identified significant broad-sense heritability of plant functional traits, basic plant defence chemistry, and arthropod community traits. The majority of arthropods were specialists, those coevolved with P. tremula to tolerate and even utilize leaf defence compounds. Arthropod abundance and richness were more closely related to plant growth rates than general chemical defences and relationships were identified between the arthropod community and stem growth, leaf and petiole morphology, anthocyanins, and condensed tannins. Heritable genetic variation in plant traits in young aspen was found to structure arthropod community; however no single trait drives the preferences of arthropod folivores among young aspen genotypes. The influence of natural variation in plant traits on the arthropod community indicates the importance of maintaining genetic variation in wild trees as keystone species for biodiversity. It further suggests that aspen can be a resource for the study of mechanisms of natural resistance to herbivores.
Highlights
Populus tremula L., is a pioneer tree valued as a host to many species of dependent flora and fauna, many of which are specialists [1,2,3,4]
In contrast to P. tremuloides, there has been a relative paucity of knowledge of the same traits in P. tremula, an interest in the European aspen has gradually emerged, recognising the genetic variation within this species [14,15] in addition to its ecological value
Despite negligible QST values for leaf traits, H2 values were moderate to high for all plant traits measured except specific leaf area, suggesting abundant genetic variation but little genetic differentiation for these traits
Summary
Populus tremula L., is a pioneer tree valued as a host to many species of dependent flora and fauna, many of which are specialists [1,2,3,4]. Aspen is a common forage food for mammals [4] and supports species of epiphytes [1,2]. In recognition of this conservation value, current forestry practice in Scandinavia retains aspens in clear-cut zones to promote biodiversity [6]. In contrast to P. tremuloides, there has been a relative paucity of knowledge of the same traits in P. tremula, an interest in the European aspen has gradually emerged, recognising the genetic variation within this species [14,15] in addition to its ecological value. Recent chemical analyses of P. tremula leaves have isolated genotype-specificity in phenolic glycoside compounds [20] recognised for their efficacy in herbivore defence in Populus [21], the response of folivorous arthropods has received little attention
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
